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Sample records for optimized surgical techniques

  1. Laparoscopic pyelolithotomy: optimizing surgical technique.

    PubMed

    Salvadó, José A; Guzmán, Sergio; Trucco, Cristian A; Parra, Claudio A

    2009-04-01

    The classic approach to renal stone disease includes shockwave lithotripsy, ureteroscopy or percutaneous nephrolithotripsy, and, in some cases, a combination of both. The usefulness of laparoscopy in this regard remains debated. In this report and video, we present our technique of laparoscopic pyelolithotomy assisted by flexible instrumentation to achieve maximal stone clearance in a selected group of patients.

  2. Laparoscopic pyelolithotomy: optimizing surgical technique.

    PubMed

    Salvadó, José A; Guzmán, Sergio; Trucco, Cristian A; Parra, Claudio A

    2009-04-01

    The classic approach to renal stone disease includes shockwave lithotripsy, ureteroscopy or percutaneous nephrolithotripsy, and, in some cases, a combination of both. The usefulness of laparoscopy in this regard remains debated. In this report and video, we present our technique of laparoscopic pyelolithotomy assisted by flexible instrumentation to achieve maximal stone clearance in a selected group of patients. PMID:19358685

  3. Surgical technique for optimal outcomes: Part I. Cutting tissue: incising, excising, and undermining.

    PubMed

    Miller, Christopher J; Antunes, Marcelo B; Sobanko, Joseph F

    2015-03-01

    Sound surgical technique is necessary to achieve excellent surgical outcomes. Despite the fact that dermatologists perform more office-based cutaneous surgery than any other specialty, few dermatologists have opportunities for practical instruction to improve surgical technique after residency and fellowship. This 2-part continuing medical education article will address key principles of surgical technique at each step of cutaneous reconstruction. Part I reviews incising, excising, and undermining. Objective quality control questions are proposed to provide a framework for self-assessment and continuous quality improvement.

  4. Laparoscopic adrenalectomy: Surgical techniques

    PubMed Central

    Mellon, Matthew J.; Sethi, Amanjot; Sundaram, Chandru P.

    2008-01-01

    Since its first description in 1992, laparoscopic adrenalectomy has become the gold standard for the surgical treatment of most adrenal conditions. The benefits of a minimally invasive approach to adrenal resection such as decreased hospital stay, shorter recovery time and improved patient satisfaction are widely accepted. However, as this procedure becomes more widespread, critical steps of the operation must be maintained to ensure expected outcomes and success. This article reviews the surgical techniques for the laparoscopic adrenalectomy. PMID:19468527

  5. Laparoscopy in the morbidly obese: physiologic considerations and surgical techniques to optimize success.

    PubMed

    Scheib, Stacey A; Tanner, Edward; Green, Isabel C; Fader, Amanda N

    2014-01-01

    The objectives of this review were to analyze the literature describing the benefits of minimally invasive gynecologic surgery in obese women, to examine the physiologic considerations associated with obesity, and to describe surgical techniques that will enable surgeons to perform laparoscopy and robotic surgery successfully in obese patients. The Medline database was reviewed for all articles published in the English language between 1993 and 2013 containing the search terms "gynecologic laparoscopy" "laparoscopy," "minimally invasive surgery and obesity," "obesity," and "robotic surgery." The incidence of obesity is increasing in the United States, and in particular morbid obesity in women. Obesity is associated with a wide range of comorbid conditions that may affect perioperative outcomes including hypertension, atherosclerosis, angina, obstructive sleep apnea, and diabetes mellitus. In obese patients, laparoscopy or robotic surgery, compared with laparotomy, is associated with a shorter hospital stay, less postoperative pain, and fewer wound complications. Specific intra-abdominal access and trocar positioning techniques, as well as anesthetic maneuvers, improve the likelihood of success of laparoscopy in women with central adiposity. Performing gynecologic laparoscopy in the morbidly obese is no longer rare. Increases in the heaviest weight categories involve changes in clinical practice patterns. With comprehensive and thoughtful preoperative and surgical planning, minimally invasive gynecologic surgery may be performed safely and is of particular benefit in obese patients. PMID:24100146

  6. Optimal Suturing Technique and Number of Sutures for Surgical Implantation of Acoustic Transmitters in Juvenile Salmonids

    SciTech Connect

    Deters, Katherine A.; Brown, Richard S.; Boyd, James W.; Eppard, M. B.; Seaburg, Adam

    2012-01-02

    The size reduction of acoustic transmitters has led to a reduction in the length of incision needed to implant a transmitter. Smaller suture knot profiles and fewer sutures may be adequate for closing an incision used to surgically implant an acoustic microtransmitter. As a result, faster surgery times and reduced tissue trauma could lead to increased survival and decreased infection for implanted fish. The objective of this study was to assess the effects of five suturing techniques on mortality, tag and suture retention, incision openness, ulceration, and redness in juvenile Chinook salmon Oncorhynchus tshawytscha implanted with acoustic microtransmitters. Suturing was performed by three surgeons, and study fish were held at two water temperatures (12°C and 17°C). Mortality was low and tag retention was high for all treatments on all examination days (7, 14, 21, and 28 days post-surgery). Because there was surgeon variation in suture retention among treatments, further analyses included only the one surgeon who received feedback training in all suturing techniques. Incision openness and tissue redness did not differ among treatments. The only difference observed among treatments was in tissue ulceration. Incisions closed with a horizontal mattress pattern had more ulceration than other treatments among fish held for 28 days at 17°C. Results from this study suggest that one simple interrupted 1 × 1 × 1 × 1 suture is adequate for closing incisions on fish under most circumstances. However, in dynamic environments, two simple interrupted 1 × 1 × 1 × 1 sutures should provide adequate incision closure. Reducing bias in survival and behavior tagging studies is important when making comparisons to the migrating salmon population. Therefore, by minimizing the effects of tagging on juvenile salmon (reduced tissue trauma and reduced surgery time), researchers can more accurately estimate survival and behavior.

  7. Neuronavigation. Principles. Surgical technique.

    PubMed

    Ivanov, Marcel; Ciurea, Alexandru Vlad

    2009-01-01

    Neuronavigation and stereotaxy are techniques designed to help neurosurgeons precisely localize different intracerebral pathological processes by using a set of preoperative images (CT, MRI, fMRI, PET, SPECT etc.). The development of computer assisted surgery was possible only after a significant technological progress, especially in the area of informatics and imagistics. The main indications of neuronavigation are represented by the targeting of small and deep intracerebral lesions and choosing the best way to treat them, in order to preserve the neurological function. Stereotaxis also allows lesioning or stimulation of basal ganglia for the treatment of movement disorders. These techniques can bring an important amount of confort both to the patient and to the neurosurgeon. Neuronavigation was introduced in Romania around 2003, in four neurosurgical centers. We present our five-years experience in neuronavigation and describe the main principles and surgical techniques.

  8. Neuronavigation. Principles. Surgical technique.

    PubMed

    Ivanov, Marcel; Ciurea, Alexandru Vlad

    2009-01-01

    Neuronavigation and stereotaxy are techniques designed to help neurosurgeons precisely localize different intracerebral pathological processes by using a set of preoperative images (CT, MRI, fMRI, PET, SPECT etc.). The development of computer assisted surgery was possible only after a significant technological progress, especially in the area of informatics and imagistics. The main indications of neuronavigation are represented by the targeting of small and deep intracerebral lesions and choosing the best way to treat them, in order to preserve the neurological function. Stereotaxis also allows lesioning or stimulation of basal ganglia for the treatment of movement disorders. These techniques can bring an important amount of confort both to the patient and to the neurosurgeon. Neuronavigation was introduced in Romania around 2003, in four neurosurgical centers. We present our five-years experience in neuronavigation and describe the main principles and surgical techniques. PMID:20108488

  9. Surgical skin-marking techniques.

    PubMed

    Granick, M S; Heckler, F R; Jones, E W

    1987-04-01

    Surgical skin-marking inks and dyes are in everyday use for designing and planning incisions in plastic and reconstructive surgery. We have traced the historical development of surgical skin-marking techniques from ancient times to the present. The biochemical characteristics of the commonly used marking agents are discussed. A three-part experiment utilizing a pig model was carried out to test the tissue inflammatory response to the various dyes and inks when used intradermally as tattoos, the persistence of such tattoos, and the ease of skin erasure for each of eight stains. Methylene blue and gentian violet are recommended as the best all-purpose marking agents. The use of proprietary inks is discouraged.

  10. Surgical skin-marking techniques.

    PubMed

    Granick, M S; Heckler, F R; Jones, E W

    1987-04-01

    Surgical skin-marking inks and dyes are in everyday use for designing and planning incisions in plastic and reconstructive surgery. We have traced the historical development of surgical skin-marking techniques from ancient times to the present. The biochemical characteristics of the commonly used marking agents are discussed. A three-part experiment utilizing a pig model was carried out to test the tissue inflammatory response to the various dyes and inks when used intradermally as tattoos, the persistence of such tattoos, and the ease of skin erasure for each of eight stains. Methylene blue and gentian violet are recommended as the best all-purpose marking agents. The use of proprietary inks is discouraged. PMID:2434965

  11. [Surgical techniques of organ transplants].

    PubMed

    Froněk, Jiří

    2015-01-01

    The list of surgical procedures of solid organ transplantations appears very interesting and colorful, even with overlap among techniques. Liver transplantation is a life-saving procedure in a majority of cases, the liver can be transplanted as a full or partial graft. The liver graft can be split for two recipients; it can also be reduced for a small recipient if splitting is not indicated. Kidney transplantation is the most common solid organ transplant procedure, the majority of kidney grafts come from brain-dead donors whereas the number of live donor transplants is increasing, also thanks to paired donation and blood group incompatible transplantation methods. The small bowel and multivisceral transplantation are rare procedures; they serve selected patients with short bowel syndrome, some patients with retroperitoneal tumors or with extensive visceral thrombosis. Solid organ transplants are well established treatment methods with good and proven outcomes. A majority of patients can return to a normal life after their transplants.

  12. [Surgical techniques of organ transplants].

    PubMed

    Froněk, Jiří

    2015-01-01

    The list of surgical procedures of solid organ transplantations appears very interesting and colorful, even with overlap among techniques. Liver transplantation is a life-saving procedure in a majority of cases, the liver can be transplanted as a full or partial graft. The liver graft can be split for two recipients; it can also be reduced for a small recipient if splitting is not indicated. Kidney transplantation is the most common solid organ transplant procedure, the majority of kidney grafts come from brain-dead donors whereas the number of live donor transplants is increasing, also thanks to paired donation and blood group incompatible transplantation methods. The small bowel and multivisceral transplantation are rare procedures; they serve selected patients with short bowel syndrome, some patients with retroperitoneal tumors or with extensive visceral thrombosis. Solid organ transplants are well established treatment methods with good and proven outcomes. A majority of patients can return to a normal life after their transplants. PMID:26585110

  13. Arthroscopic Posterior Subtalar Arthrodesis: Surgical Technique

    PubMed Central

    Vilá y Rico, Jesús; Ojeda Thies, Cristina; Parra Sanchez, Guillermo

    2016-01-01

    Surgical fusion of the subtalar joint is a procedure indicated to alleviate pain of subtalar origin, such as in post-traumatic osteoarthritis, adult-acquired flatfoot deformity, and other disorders. Open subtalar arthrodesis has been performed with predictable results, but concerns exist regarding injury to proprioception and local vascularity due to wide surgical dissection. Minimally invasive techniques try to improve results by avoiding these issues but have a reputation for being technically demanding. We describe the surgical technique for arthroscopic subtalar arthrodesis, which has proved to be a safe and reliable technique in our experience, with consistent improvements in American Orthopaedic Foot & Ankle Society scores. PMID:27073783

  14. Cochlear implant simulator for surgical technique analysis

    NASA Astrophysics Data System (ADS)

    Turok, Rebecca L.; Labadie, Robert F.; Wanna, George B.; Dawant, Benoit M.; Noble, Jack H.

    2014-03-01

    Cochlear Implant (CI) surgery is a procedure in which an electrode array is inserted into the cochlea. The electrode array is used to stimulate auditory nerve fibers and restore hearing for people with severe to profound hearing loss. The primary goals when placing the electrode array are to fully insert the array into the cochlea while minimizing trauma to the cochlea. Studying the relationship between surgical outcome and various surgical techniques has been difficult since trauma and electrode placement are generally unknown without histology. Our group has created a CI placement simulator that combines an interactive 3D visualization environment with a haptic-feedback-enabled controller. Surgical techniques and patient anatomy can be varied between simulations so that outcomes can be studied under varied conditions. With this system, we envision that through numerous trials we will be able to statistically analyze how outcomes relate to surgical techniques. As a first test of this system, in this work, we have designed an experiment in which we compare the spatial distribution of forces imparted to the cochlea in the array insertion procedure when using two different but commonly used surgical techniques for cochlear access, called round window and cochleostomy access. Our results suggest that CIs implanted using round window access may cause less trauma to deeper intracochlear structures than cochleostomy techniques. This result is of interest because it challenges traditional thinking in the otological community but might offer an explanation for recent anecdotal evidence that suggests that round window access techniques lead to better outcomes.

  15. Laparoscopic Surgical Techniques for Endometriosis and Adenomyosis

    PubMed Central

    Wood, C.; Maher, P.; Woods, R.

    2000-01-01

    The details of surgical techniques for laparoscopic removal of endometriosis and adenomyosis are described briefly in textbooks and gynaecological journal articles. We have described a wide variety of techniques for the various procedures required in the treatment of endometriosis and adenomyosis, excluding hysterectomy. The principles are based upon those used in removal of primary cancer lesions. The limitations of thermal ablation are discussed, and evidence of improved results after excision of lesions have been submitted for publication. PMID:18493534

  16. [Idiopathic Progressive Subglottic Stenosis: Surgical Techniques].

    PubMed

    Hoetzenecker, K; Schweiger, T; Klepetko, W

    2016-09-01

    Idiopathic subglottic stenosis is a disease characterized by slow, progressive scarring and constriction of the subglottic airway. It almost always occurs in females between the 3rd and 5th decade of life. Symptoms are frequently misinterpreted as asthma and patients are referred for endoscopic evaluation only when asthma medications fail to alleviate their symptoms. Treatment options can be divided into endoscopic and open surgical techniques. Microlaryngoscopic scar reduction by laser followed by balloon dilation usually delivers good short-term results. However, the majority of patients will experience restenosis within a short period of time. Open surgical correction techniques are based on a complete removal of the affected airway segment. This must be combined with various extended resection techniques in patients with advanced stenosis. Depending on the extent and severity of the stenosis the following surgical techniques are required: standard cricotracheal resection (Grillo's technique), cricoplasty with dorsal and lateral mucosaplasty, or a combination of resection and enlargement techniques using rib cartilage grafts. In experienced centres, success rates of over 95 % are reported with good functional outcome of voice and deglutition. PMID:27607884

  17. [Idiopathic Progressive Subglottic Stenosis: Surgical Techniques].

    PubMed

    Hoetzenecker, K; Schweiger, T; Klepetko, W

    2016-09-01

    Idiopathic subglottic stenosis is a disease characterized by slow, progressive scarring and constriction of the subglottic airway. It almost always occurs in females between the 3rd and 5th decade of life. Symptoms are frequently misinterpreted as asthma and patients are referred for endoscopic evaluation only when asthma medications fail to alleviate their symptoms. Treatment options can be divided into endoscopic and open surgical techniques. Microlaryngoscopic scar reduction by laser followed by balloon dilation usually delivers good short-term results. However, the majority of patients will experience restenosis within a short period of time. Open surgical correction techniques are based on a complete removal of the affected airway segment. This must be combined with various extended resection techniques in patients with advanced stenosis. Depending on the extent and severity of the stenosis the following surgical techniques are required: standard cricotracheal resection (Grillo's technique), cricoplasty with dorsal and lateral mucosaplasty, or a combination of resection and enlargement techniques using rib cartilage grafts. In experienced centres, success rates of over 95 % are reported with good functional outcome of voice and deglutition.

  18. Surgical hip dislocation: techniques for success.

    PubMed

    Ricciardi, Benjamin F; Sink, Ernest L

    2014-01-01

    Surgical hip dislocation (SHD) is a versatile approach used to address both intra-articular and extra-articular pathology around the hip joint in both pediatric and adult patients. It allows anterior dislocation of the femoral head for direct visualization of the hip joint while preserving femoral head vascularity and minimizing trauma to the abductor musculature. Previously described indications for SHD include femoroacetabular impingement, deformity resulting from Legg-Calve-Perthes disease, slipped capital femoral epiphysis, periarticular trauma, benign lesions of the hip joint, and osteochondral lesions. In this review, we will describe current surgical techniques, indications, and clinical outcomes for SHD. PMID:25207733

  19. Rhinoplasty: surface aesthetics and surgical techniques.

    PubMed

    Çakir, Bariş; Doğan, Teoman; Öreroğlu, Ali Riza; Daniel, Rollin K

    2013-03-01

    Surface aesthetics of the attractive nose are created by certain lines, shadows, and highlights, with specific proportions and breakpoints. Our evaluation of the nasal surface aesthetics is achieved using the concept of geometric polygons as aesthetic subunits, both to define the existing deformity and the aesthetic goals. Surgical techniques have been developed and modified to achieve the desired surface appearance, and those are detailed in this article. The principles of geometric polygons allow the surgeon to analyze the deformities of the nose, to define an operative plan to achieve specific goals, and to select the appropriate operative technique. These aesthetic concepts and surgical techniques were used in 257 consecutive rhinoplasties performed in the past 3 years by the principal author (B.Ç.).

  20. Surgical discectomy for lumbar disc herniation: surgical techniques.

    PubMed

    Blamoutier, A

    2013-02-01

    Discectomy for lumbar discal herniation is the most commonly performed spinal surgery. The basic principle of the various techniques is to relieve the nerve root compression induced by the herniation. Initially, the approach was a unilateral posterior 5-cm incision: the multifidus was detached from the vertebra, giving access through an interlaminar space in case of posterolateral herniation; an alternative paraspinal approach was used for extraforaminal herniation. Over the past 30 years, many technical improvements have decreased operative trauma by reducing incision size, thereby reducing postoperative pain and hospital stay and time off work, while improving clinical outcome. Magnification and illumination systems by microscope and endoscope have been introduced to enable minimally invasive techniques. Several comparative studies have analyzed the clinical results of these various techniques. Although the methodology of most of these studies is debatable, all approaches seem to provide clinical outcomes of similar quality. At all events, minimally invasive techniques reduce hospital stay. While technical proficiency is essential, the final result depends on strict compliance with a prerequisite for surgical indication: close correlation between clinical symptoms and radiological findings. It is essential to discuss the risk/benefit ratio and explain the pros and cons of the recommended technique to the patient. PMID:23352565

  1. Surgical implantation techniques for electronic tags in fish

    SciTech Connect

    Wagner, Glenn N.; Cooke, Steven J.; Brown, Richard S.; Deters, Katherine A.

    2011-01-01

    Intracoelomic implantation of transmitters into fish requires making a surgical incision, incision closure, and other surgery related techniques; however, the tools and techniques used in the surgical process vary widely. We review the available literature and focus on tools and techniques used for conducting surgery on juvenile salmonids because of the large amount of research that is conducted on them. The use of sterilized surgical instruments properly selected for a given size of fish will minimize tissue damage and infection rates, and speed the wound healing of fish implanted with transmitters. For the implantation of transmitters into small fish, the optimal surgical methods include making an incision on the ventral midline along the linea alba (for studies under 1 month), protecting the viscera (by lifting the skin with forceps while creating the incision), and using absorbable monofilament suture with a small-swaged-on swaged-on tapered or reverse-cutting needle. Standardizing the implantation techniques to be used in a study involving particular species and age classes of fish will improve survival and transmitter retention while allowing for comparisons to be made among studies and across multiple years. This review should be useful for researchers working on juvenile salmonids and other sizes and species of fish.

  2. Post-traumatic knee stiffness: surgical techniques.

    PubMed

    Pujol, N; Boisrenoult, P; Beaufils, P

    2015-02-01

    Post-traumatic knee stiffness and loss of range of motion is a common complication of injuries to the knee area. The causes of post-traumatic knee stiffness can be divided into flexion contractures, extension contractures, and combined contractures. Post-traumatic stiffness can be due to the presence of dense intra-articular adhesions and/or fibrotic transformation of peri-articular structures. Various open and arthroscopic surgical treatments are possible. A precise diagnosis and understanding of the pathology is mandatory prior to any surgical treatment. Failure is imminent if all pathologies are not addressed correctly. From a general point of view, a flexion contracture is due to posterior adhesions and/or anterior impingement. On the other hand, extension contractures are due to anterior adhesions and/or posterior impingement. This overview will describe the different modern surgical techniques for treating post-traumatic knee stiffness. Any bony impingements must be treated before soft tissue release is performed. Intra-articular stiff knees with a loss of flexion can be treated by an anterior arthroscopic arthrolysis. Extra-articular pathology causing a flexion contracture can be treated by open or endoscopic quadriceps release. Extension contractures can be treated by arthroscopic or open posterior arthrolysis. Postoperative care (analgesia, rehabilitation) is essential to maintaining the range of motion obtained intra-operatively.

  3. Metacarpal Neck Fractures: A Review of Surgical Indications and Techniques

    PubMed Central

    Padegimas, Eric M.; Warrender, William J.; Jones, Christopher M.; Ilyas, Asif M.

    2016-01-01

    Context Hand injuries are a common emergency department presentation. Metacarpal fractures account for 40% of all hand fractures and can be seen in the setting of low or high energy trauma. The most common injury pattern is a metacarpal neck fracture. In this study, the authors aim to review the surgical indications for metacarpal neck fractures, the fixation options available along with the risk and benefits of each. Evidence Acquisition Literature review of the different treatment modalities for metacarpal neck fractures. Review focuses on surgical indications and the risks and benefits of different operative techniques. Results The indications for surgery are based on the amount of dorsal angulation of the distal fragment. The ulnar digits can tolerate greater angulation as the radial digits more easily lose grip strength. The most widely utilized fixation techniques are pinning with k-wires, dorsal plating, or intramedullary fixation. There is currently no consensus on an optimal fixation technique as surgical management has been found to have a complication rate up to 36%. Plate and screw fixation demonstrated especially high complication rates. Conclusions Metacarpal neck fractures are a common injury in young and active patients that results in substantial missed time from work. While the surgical indications are well-described, there is no consensus on the optimal treatment modality because of high complication rates. Dorsal plating has higher complication rates than closed reduction and percutaneous pinning, but is necessary in comminuted fractures. The lack of an ideal fixation construct suggests that further study of the commonly utilized techniques as well as novel techniques is necessary. PMID:27800460

  4. Code Optimization Techniques

    SciTech Connect

    MAGEE,GLEN I.

    2000-08-03

    Computers transfer data in a number of different ways. Whether through a serial port, a parallel port, over a modem, over an ethernet cable, or internally from a hard disk to memory, some data will be lost. To compensate for that loss, numerous error detection and correction algorithms have been developed. One of the most common error correction codes is the Reed-Solomon code, which is a special subset of BCH (Bose-Chaudhuri-Hocquenghem) linear cyclic block codes. In the AURA project, an unmanned aircraft sends the data it collects back to earth so it can be analyzed during flight and possible flight modifications made. To counter possible data corruption during transmission, the data is encoded using a multi-block Reed-Solomon implementation with a possibly shortened final block. In order to maximize the amount of data transmitted, it was necessary to reduce the computation time of a Reed-Solomon encoding to three percent of the processor's time. To achieve such a reduction, many code optimization techniques were employed. This paper outlines the steps taken to reduce the processing time of a Reed-Solomon encoding and the insight into modern optimization techniques gained from the experience.

  5. [Salter innominate osteotomy : Indications, surgical technique, results].

    PubMed

    Schulze, A; Tingart, M

    2016-08-01

    The prevalence of congenital hip dysplasia in Germany is 2-4 % and that of hip dislocation is 0.5-1 %. If early therapy is not successful or the hip dysplasia or dislocation is diagnosed too late (children of over 1 year of age) surgical treatment is indicated to increase the femoral coverage. The innominate osteotomy, published by Robert B. Salter 1961, is a worldwide established technique to improve the lateral and ventral coverage of the femoral head in primary or secondary hip dysplasia or dislocation. In this paper we discuss Salter's technique and present indications, the perioperative procedure, operative modifications and operative extensions and demonstrate the anatomical requirements, postoperative biomechanical changes and long-term results.

  6. [Salter innominate osteotomy : Indications, surgical technique, results].

    PubMed

    Schulze, A; Tingart, M

    2016-08-01

    The prevalence of congenital hip dysplasia in Germany is 2-4 % and that of hip dislocation is 0.5-1 %. If early therapy is not successful or the hip dysplasia or dislocation is diagnosed too late (children of over 1 year of age) surgical treatment is indicated to increase the femoral coverage. The innominate osteotomy, published by Robert B. Salter 1961, is a worldwide established technique to improve the lateral and ventral coverage of the femoral head in primary or secondary hip dysplasia or dislocation. In this paper we discuss Salter's technique and present indications, the perioperative procedure, operative modifications and operative extensions and demonstrate the anatomical requirements, postoperative biomechanical changes and long-term results. PMID:27351429

  7. Surgical techniques in type A dissection.

    PubMed

    Hussain, Syed T; Svensson, Lars G

    2016-05-01

    Acute aortic dissection is a surgical emergency that must be urgently managed, with the primary goal of restoring flow to the dominant true lumen in the downstream aorta. Our preference at the Cleveland Clinic is for an open distal anastomosis technique without aortic clamping, as it permits more accurate approximation of dissected layers and more homeostatically secure anastomosis. During this procedure we employ right axillary end-to-side graft perfusion, followed by deep hypothermic circulatory arrest and antegrade brain perfusion. The distal anastomosis is performed without felt strips or glue. Critical to achieving a successful outcome is meticulous de-airing of the arch, diligent myocardial protection, and a water-tight anastomosis prior to discontinuing cardiopulmonary bypass. PMID:27386412

  8. Surgical techniques in type A dissection

    PubMed Central

    Hussain, Syed T.

    2016-01-01

    Acute aortic dissection is a surgical emergency that must be urgently managed, with the primary goal of restoring flow to the dominant true lumen in the downstream aorta. Our preference at the Cleveland Clinic is for an open distal anastomosis technique without aortic clamping, as it permits more accurate approximation of dissected layers and more homeostatically secure anastomosis. During this procedure we employ right axillary end-to-side graft perfusion, followed by deep hypothermic circulatory arrest and antegrade brain perfusion. The distal anastomosis is performed without felt strips or glue. Critical to achieving a successful outcome is meticulous de-airing of the arch, diligent myocardial protection, and a water-tight anastomosis prior to discontinuing cardiopulmonary bypass. PMID:27386412

  9. [Robot-assisted laparoscopic prostatectomy: surgical technique].

    PubMed

    Rocco, B; Coelho, R F; Albo, G; Patel, V R

    2010-09-01

    Prostate tumours are among the most frequently diagnosed solid tumours in males (a total of 192,280 new cases in the USA in 2009); since the approval of the PSA test by the Food and Drug Administration in 1986, incidence has risen significantly, particularly in the '90s; furthermore the spread of the PSA test has led to an increased frequency of cancer diagnosis at the localised stage. The standard treatment for tumour of the prostate is retropubic radical prostatectomy (RRP) which however is not morbidity-free, e.g. intraoperative bleeding, urinary incontinence and erectile dysfunction. This is why the interest of the scientific community has turned increasingly to mini-invasive surgical procedures able to achieve the same oncological results as the open procedure, but which also reduce the impact of the treatment on these patients' quality of life. The first step in this direction was laparoscopic prostatectomy described by Schuessler in 1992 and standardised by Gaston in 1997. However, the technical difficulty inherent in this procedure has limited its more widespread use. In May 2000 Binder and Kramer published a report on the first robot-assisted prostatectomy (RARP) using the Da Vinci system (da Vinci TM, Intuitive Surgical, Sunnyvale, CA, USA). From the original experience, RARP, which exploits the advantages of an enlarged, three-dimensional view and the ability of the instruments to move with 7 degrees of freedom, the technique has spread enormously all over the world. At the time of writing, in the USA, RARP is the most common therapeutic option for the treatment of prostate tumour at localised stage. In the present study we describe the RARP technique proposed by dr. Vipul Patel, head of the Global Robotic Institute (Orlando Fl). PMID:20940698

  10. Sternoclavicular dislocation: case report and surgical technique.

    PubMed

    Terra, Bernardo Barcellos; Rodrigues, Leandro Marano; Pádua, David Victoria Hoffmann; Martins, Marcelo Giovanini; Teixeira, João Carlos de Medeiros; De Nadai, Anderson

    2015-01-01

    Sternoclavicular dislocations account for less than 5% of all dislocations of the scapular belt. Most cases of anterior dislocation of the sternoclavicular joint do not present symptoms. However, some patients may develop chronic anterior instability and remain symptomatic, and surgical treatment is indicated in these cases. There is a scarcity of reports in the literature relating to reconstruction using the long palmar tendon in cases of traumatic anterior instability. Although rare, these injuries deserve rapid diagnosis and efficient treatment in order to avoid future complications. The aim of this report was to report on a case of a motocross competitor who developed chronic traumatic anterior instability of the sternoclavicular joint and underwent surgical reconstruction using the autogenous long palmar tendon. The patient was a 33-year-old man with a history of anterior dislocation of the sternoclavicular subsequent to a fall during a maneuver in a motocross competition. Conservative treatment was instituted initially, consisting of use of a functional sling to treat the symptoms for 3 weeks, along with physiotherapeutic rehabilitation for 3 months. We chose to use a modification of the "figure of eight" technique based on the studies by Spencer and Kuhn. A longitudinal incision of approximately 10 cm was made at the level of the sternoclavicular joint. The graft from the ipsilateral long palmar tendon was passed through the orifices in the form of a modified "figure of eight" and its ends were sutured together. The patient was immobilized using an American sling for 4 weeks. After 6 months of follow-up, the patient no longer presented pain or instability when movement of the sternoclavicular joint was required. Minor discomfort and slight prominence of the sternoclavicular joint continued to be present but did not affect the patient's activities. Thus, the patient was able to return to racing 6 months after the operation. Our study presented a case of

  11. The AO Ulnar Shortening Osteotomy System Indications and Surgical Technique

    PubMed Central

    Nagy, Ladislav; Jungwirth-Weinberger, Anna; Campbell, Douglas; Pino, Juan González del

    2014-01-01

    Ulnar shortening osteotomy is an established and frequently performed surgical procedure in wrist surgery. The technical aspects of the procedure have continued to develop in recent years, with instruments and implants being developed specifically for this purpose. Ulnar shortening osteotomy is required for different clinical indications and situations. These varying indications demand different amounts of shortening, but all must be precise and accurate. Controversy exists as to how this can best be achieved in terms of the location for osteotomy, the surgical approach and geometry of the osteotomy, as well as which implant to use to provide optimal stability. The goal of all techniques (besides successfully resolving the underlying problem) is to achieve reliable and rapid bone union without compromising early functional rehabilitation and also to avoid hardware complications. The AO Hand Expert Group has developed a specialized instrumentation system with dedicated and specifically designed implants to ensure exact and accurate cutting with precise and rigid stabilization of the ulna. The matched drill guides and double-blade saws allow accurate completion of the planned amount of shortening together with precise coaptation of the osteotomy fragments. The specific ulnar osteotomy LCP (locking compression plate) combines maximum stability with minimum bulk and soft tissue irritation. The features of the implant, its surgical technique, and early results are described. PMID:25077046

  12. Evolving Educational Techniques in Surgical Training.

    PubMed

    Evans, Charity H; Schenarts, Kimberly D

    2016-02-01

    Training competent and professional surgeons efficiently and effectively requires innovation and modernization of educational methods. Today's medical learner is quite adept at using multiple platforms to gain information, providing surgical educators with numerous innovative avenues to promote learning. With the growth of technology, and the restriction of work hours in surgical education, there has been an increase in use of simulation, including virtual reality, robotics, telemedicine, and gaming. The use of simulation has shifted the learning of basic surgical skills to the laboratory, reserving limited time in the operating room for the acquisition of complex surgical skills". PMID:26612021

  13. Evolving Educational Techniques in Surgical Training.

    PubMed

    Evans, Charity H; Schenarts, Kimberly D

    2016-02-01

    Training competent and professional surgeons efficiently and effectively requires innovation and modernization of educational methods. Today's medical learner is quite adept at using multiple platforms to gain information, providing surgical educators with numerous innovative avenues to promote learning. With the growth of technology, and the restriction of work hours in surgical education, there has been an increase in use of simulation, including virtual reality, robotics, telemedicine, and gaming. The use of simulation has shifted the learning of basic surgical skills to the laboratory, reserving limited time in the operating room for the acquisition of complex surgical skills".

  14. [Robot-assisted radical prostatectomy: surgical techniques].

    PubMed

    Kojima, Yoshiyuki; Sato, Yuichi; Ogawa, Soichiro; Haga, Nobuhiro; Yanagida, Tomohiko

    2016-01-01

    Robot-assisted radical prostatectomy (RARP) for the patients with localized prostate cancer is increasingly being adopted around the world. The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) provides the advantages of simplification and precision of exposure and suturing because of allowing movements of the robotic arm in real time with increased degree of freedom and magnified 3-dimensional view. Therefore, RARP has been expected to provide superior therapeutic benefit to patients in terms of surgical outcome to open or laparoscopic radical prostatectomy. In this review, we provide our technical aspects and tips and tricks of RARP to improve surgical outcome and postoperative quality of life. PMID:26793888

  15. Surgical Techniques. Second Edition. Teacher Edition.

    ERIC Educational Resources Information Center

    Bushey, Vicki; And Others

    This instructor's manual contains 18 units of instruction for a course on surgical technology designed to include the entry-level competencies students need as a surgical technologist. Each unit includes some or all of the following basic components of a unit of instruction: objective sheet, suggested activities for the teacher, assignment sheets…

  16. Tibial inlay posterior cruciate ligament reconstruction: surgical technique and results.

    PubMed

    McAllister, David R; Hussain, Suleman M

    2010-12-01

    Posterior cruciate ligament (PCL) injuries occur much less frequently than other ligament injuries of the knee such as anterior cruciate ligament injuries. There is general agreement for nonoperative treatment for lower grade injuries such as type I PCL injuries. However, for more severe injuries which may require surgery, there is no consensus on an optimal reconstruction method. Multiple arthroscopic and open techniques exist to reconstruct the PCL. Limited clinical outcomes data reveals good short-term clinical results with different reconstruction options. Biomechanical data has helped further the understanding regarding the performance of different reconstructions. This article will present a surgical technique for single bundle tibial inlay reconstruction of the PCL along with the objective biomechanical data that supports this reconstruction.

  17. Computer-Assisted Technique for Surgical Tooth Extraction

    PubMed Central

    Hamza, Hosamuddin

    2016-01-01

    Introduction. Surgical tooth extraction is a common procedure in dentistry. However, numerous extraction cases show a high level of difficulty in practice. This difficulty is usually related to inadequate visualization, improper instrumentation, or other factors related to the targeted tooth (e.g., ankyloses or presence of bony undercut). Methods. In this work, the author presents a new technique for surgical tooth extraction based on 3D imaging, computer planning, and a new concept of computer-assisted manufacturing. Results. The outcome of this work is a surgical guide made by 3D printing of plastics and CNC of metals (hybrid outcome). In addition, the conventional surgical cutting tools (surgical burs) are modified with a number of stoppers adjusted to avoid any excessive drilling that could harm bone or other vital structures. Conclusion. The present outcome could provide a minimally invasive technique to overcome the routine complications facing dental surgeons in surgical extraction procedures. PMID:27127510

  18. Computer-Assisted Technique for Surgical Tooth Extraction.

    PubMed

    Hamza, Hosamuddin

    2016-01-01

    Introduction. Surgical tooth extraction is a common procedure in dentistry. However, numerous extraction cases show a high level of difficulty in practice. This difficulty is usually related to inadequate visualization, improper instrumentation, or other factors related to the targeted tooth (e.g., ankyloses or presence of bony undercut). Methods. In this work, the author presents a new technique for surgical tooth extraction based on 3D imaging, computer planning, and a new concept of computer-assisted manufacturing. Results. The outcome of this work is a surgical guide made by 3D printing of plastics and CNC of metals (hybrid outcome). In addition, the conventional surgical cutting tools (surgical burs) are modified with a number of stoppers adjusted to avoid any excessive drilling that could harm bone or other vital structures. Conclusion. The present outcome could provide a minimally invasive technique to overcome the routine complications facing dental surgeons in surgical extraction procedures. PMID:27127510

  19. Hysteroscopic metroplasty: surgical technique and obstetric outcome.

    PubMed

    Daly, D C; Walters, C A; Soto-Albors, C E; Riddick, D H

    1983-05-01

    Congenital Müllerian abnormalities, particularly the septate uterus, may result in recurrent abortion or premature labor. Twenty-five patients found to have a septate uterus during evaluation for infertility or recurrent abortion were treated by hysteroscopic metroplasty with laparoscopic visualization. Surgical outcome was excellent, intraoperative and postoperative morbidity was negligible, and the postoperative course was similar to that following laparoscopy alone. Preoperative fetal wastage in 17 previously fertile patients was 90%. Of 11 patients, 6 or more months postoperatively, 10 had conceived: 5 delivered vaginally at term, 2 delivered by cesarean section, and 2 pregnancies are in progress. One pregnancy miscarried at 21 weeks secondary to an incompetent cervix. With hysteroscopic metroplasty, septa can be incised successfully with lower morbidity and as good a surgical outcome as with abdominal procedures. If further studies confirm the pregnancy outcome reported, then hysteroscopic metroplasty should become the treatment of choice for the septate uterus.

  20. Supramalleolar Osteotomy: Indications and Surgical Techniques.

    PubMed

    Mulhern, Jennifer L; Protzman, Nicole M; Brigido, Stephen A; Deol, Premjit Pete S

    2015-07-01

    Supramalleolar osteotomies are a surgical treatment option for asymmetric varus or valgus ankle arthritis where at least 50% of the joint surface is spared. Procedure selection requires significant preoperative planning for appropriate execution. Thus, the surgeon must be familiar with the principles of deformity correction. With appropriate patient selection and proper preoperative planning, the procedure has been shown to yield excellent results, redistributing forces more evenly across the ankle joint by restoring the mechanical axis of the lower leg with minimal complications.

  1. Minimally invasive surgical techniques in periodontal regeneration.

    PubMed

    Cortellini, Pierpaolo

    2012-09-01

    A review of the current scientific literature was undertaken to evaluate the efficacy of minimally invasive periodontal regenerative surgery in the treatment of periodontal defects. The impact on clinical outcomes, surgical chair-time, side effects and patient morbidity were evaluated. An electronic search of PUBMED database from January 1987 to December 2011 was undertaken on dental journals using the key-word "minimally invasive surgery". Cohort studies, retrospective studies and randomized controlled clinical trials referring to treatment of periodontal defects with at least 6 months of follow-up were selected. Quality assessment of the selected studies was done through the Strength of Recommendation Taxonomy Grading (SORT) System. Ten studies (1 retrospective, 5 cohorts and 4 RCTs) were included. All the studies consistently support the efficacy of minimally invasive surgery in the treatment of periodontal defects in terms of clinical attachment level gain, probing pocket depth reduction and minimal gingival recession. Six studies reporting on side effects and patient morbidity consistently indicate very low levels of pain and discomfort during and after surgery resulting in a reduced intake of pain-killers and very limited interference with daily activities in the post-operative period. Minimally invasive surgery might be considered a true reality in the field of periodontal regeneration. The observed clinical improvements are consistently associated with very limited morbidity to the patient during the surgical procedure as well as in the post-operative period. Minimally invasive surgery, however, cannot be applied at all cases. A stepwise decisional algorithm should support clinicians in choosing the treatment approach.

  2. Optimization of care for the pediatric surgical patient: Why now?

    PubMed

    Arca, Marjorie J; Goldin, Adam B; Oldham, Keith T

    2015-12-01

    In 2015, the American College of Surgeons (ACS) has begun to verify hospitals and ambulatory centers which meet consensus based optimal resource standards as "Children׳s Surgical Centers." The intent is to identify children-specific resources available within an institution and using a stratification system similar to the ACS Trauma Program match these to the needs of infants and children with surgical problems. This review briefly summarizes the history, supporting data and processes which drove this initiative.

  3. Retrospective evaluation of surgical endodontic treatment: traditional versus modern technique.

    PubMed

    Tsesis, Igor; Rosen, Eyal; Schwartz-Arad, Devorah; Fuss, Zvi

    2006-05-01

    The aim of this retrospective study was to compare the outcome of surgical endodontic treatment preformed using the traditional versus modern techniques. There were 110 patients who were treated by surgical endodontic treatment between 2000 and 2002 and evaluated from their dental charts. The surgical endodontic treatment was preformed using a traditional or modern technique. The traditional technique included root-end resection with a 45 degrees bevel angle, and retrograde preparation using a carbide round bur. The modern technique included root-end resection with minimal or no bevel, and retrograde preparation using ultrasonic retro-tips with the aid of a dental operating microscope. The retrograde filling material for both techniques was intermediate restorative material. There were 71 patients with 88 treated teeth that were compatible with the inclusion criteria. Complete healing rate for the teeth treated with the modern technique (91.1%) was significantly higher than that for teeth treated using the traditional technique (44.2%) (p < 0.0001). In the traditional technique a significant (p = 0.032) negative influence of the tooth type was found. Modern surgical endodontic treatment using operative microscope and ultrasonic tips significantly improves the outcome of the therapy compared to the traditional technique.

  4. Technique of surgical sex reassignment for micropenis and allied conditions.

    PubMed

    Jones, H W; Park, I J; Rock, J A

    1978-12-15

    Although the etiology of micropenis is diverse, individuals who have in common a penile length of 2 cm. or less at birth do not function well as men. For this reason, during the last 18 years, 10 individuals with this problem were selected for surgical sex reassignment. The technique of the surgical procedure is described. The immediate results are considered to be cosmetically satisfactory, and the long-term results, as judged by two individuals who have been observed for 18 plus years seem to indicate that surgical sex reassignment is a useful procedure in selected patients with this disorder.

  5. Techniques for shuttle trajectory optimization

    NASA Technical Reports Server (NTRS)

    Edge, E. R.; Shieh, C. J.; Powers, W. F.

    1973-01-01

    The application of recently developed function-space Davidon-type techniques to the shuttle ascent trajectory optimization problem is discussed along with an investigation of the recently developed PRAXIS algorithm for parameter optimization. At the outset of this analysis, the major deficiency of the function-space algorithms was their potential storage problems. Since most previous analyses of the methods were with relatively low-dimension problems, no storage problems were encountered. However, in shuttle trajectory optimization, storage is a problem, and this problem was handled efficiently. Topics discussed include: the shuttle ascent model and the development of the particular optimization equations; the function-space algorithms; the operation of the algorithm and typical simulations; variable final-time problem considerations; and a modification of Powell's algorithm.

  6. Powered instrumentation in functional endoscopic sinus surgery. I: Surgical technique.

    PubMed

    Christmas, D A; Krouse, J H

    1996-01-01

    The use of the microdebrider provides an excellent, safe and thorough technique in functional endoscopic sinus surgery. It provides atraumatic dissection with minimal bleeding which enables decreased surgical time and faster postoperative healing. It is easily learned and requires minimal supplemental instrumentation. We feel that it is a superior technique in the practice of functional endoscopic sinus surgery.

  7. First-trimester surgical abortion technique.

    PubMed

    Yonke, Nicole; Leeman, Lawrence M

    2013-12-01

    New data have emerged to support changes in first-trimester abortion practice in regard to antibiotic prophylaxis, cervical ripening, the use of manual vacuum aspiration, and pain management. This article addresses these new recommendations and reviews techniques in performing manual and electric vacuum uterine aspiration procedures before 14 weeks' gestation, including very early abortion (<7 weeks' gestation), technically difficult abortions, management of complications, and postabortal contraception. The information discussed also applies to miscarriage management.

  8. Soft Tissue Surgical Procedures for Optimizing Anterior Implant Esthetics

    PubMed Central

    Ioannou, Andreas L.; Kotsakis, Georgios A.; McHale, Michelle G.; Lareau, Donald E.; Hinrichs, James E.; Romanos, Georgios E.

    2015-01-01

    Implant dentistry has been established as a predictable treatment with excellent clinical success to replace missing or nonrestorable teeth. A successful esthetic implant reconstruction is predicated on two fundamental components: the reproduction of the natural tooth characteristics on the implant crown and the establishment of soft tissue housing that will simulate a healthy periodontium. In order for an implant to optimally rehabilitate esthetics, the peri-implant soft tissues must be preserved and/or augmented by means of periodontal surgical procedures. Clinicians who practice implant dentistry should strive to achieve an esthetically successful outcome beyond just osseointegration. Knowledge of a variety of available techniques and proper treatment planning enables the clinician to meet the ever-increasing esthetic demands as requested by patients. The purpose of this paper is to enhance the implant surgeon's rationale and techniques beyond that of simply placing a functional restoration in an edentulous site to a level whereby an implant-supported restoration is placed in reconstructed soft tissue, so the site is indiscernible from a natural tooth. PMID:26124837

  9. Three-piece Inflatable Penile Prosthesis: Surgical Techniques and Pitfalls

    PubMed Central

    Al-Enezi, Ahmad; Al-Khadhari, Sulaiman; Al-Shaiji, Tariq F.

    2011-01-01

    Penile prosthesis surgery plays a vital role in the treatment of erectile dysfunction (ED). As far as outcome is concerned, it is one of the most rewarding procedures for both patients and surgeons. We describe our surgical technique for implantation of the three-piece inflatable penile prosthesis and point out the major surgical pitfalls accompanying this procedure and their specific management. The psychological outcome of penile prosthesis surgery is also discussed. Different surgical approaches are available when performing the procedure. A number of procedure-related problems can be encountered and a thorough knowledge of these is of paramount importance. Penile prosthesis surgery has a favorable psychological outcome. Surgery for implantation of an inflatable penile prosthesis is a rewarding procedure, with a high yield of patient satisfaction. Urologists should have thorough understanding of the surgical pitfalls peculiar to this procedure and their management. PMID:22413049

  10. HOSPITALIZATION TIME AFTER OPEN APPENDECTOMY BY THREE DIFFERENT SURGICAL TECHNIQUES

    PubMed Central

    XIMENES, Agláia Moreira Garcia; MELLO, Fernando Salvo Torres; de LIMA-JÚNIOR, Zailton Bezerra; FERREIRA, Cícero Faustino; CAVALCANTI, Amanda Dantas Ferreira; DIAS-FILHO, Adalberto Vieira

    2014-01-01

    Background The choice of surgical technique to approach the appendicular stump depends mostly on skill and personal preference of the surgeon or on the protocol used in the service, and the influence of this choice in hospitalization time is not evaluated. Aim To evaluate the relation between surgical technique and postoperative hospitalization time in patients presenting with acute appendicitis. Methods Retrospective analysis of 180 patients who underwent open appendectomy. These where divided into three groups according to surgical technique: conventional appendectomy (simple ligation of the stump), tobacco pouch suture and Parker-Kerr suture. Data where crossed with hospitalization time (until three days, from four to six days and over seven days). Results A hundred and eighty patients with age from 15 to 85 years where included. From these, 95 underwent conventional technique, had an average hospitalization time of 3,9 days and seven had complications (surgical site infection, seroma, suture dehiscence and evisceration). In 67 patients, tobacco pouch suture was chosen and had average hospitalization time of 3,7 days and two complications (infection and seroma). In 18 Parker-Kerr suture was made, with average hospitalization time of 2,6 days, with no complication. Contingency coefficient between the variables hospitalization time and technique was 0,255 and Cramér's V was 0,186. Conclusion There was tendency to larger hospitalization time and larger number of complications in conventional appendectomy, whereas in patients where Parker-Kerr suture was performed, hospitalization time was significantly smaller. PMID:25184769

  11. Surgical Approaches to the Acetabulum and Modifications in Technique.

    PubMed

    Cutrera, Norele Jean; Pinkas, Daphne; Toro, Jose Bernardo

    2015-10-01

    Acetabular injuries are often difficult to treat because the acetabulum is surrounded by many important structures, making access difficult and sometimes dangerous. Surgical exposures of the acetabulum are complex and require significant skill and in-depth knowledge of pelvic anatomy. Each approach has its limitations, and the potential morbidity associated with these exposures can be daunting. Recent modifications to traditional acetabular approaches have been developed to address these issues. Knowledge of the ilioinguinal, Kocher-Langenbeck, and extended iliofemoral surgical exposures and the potential drawbacks associated with each approach are essential to optimize treatment and minimize morbidity.

  12. Some Observations on Veterinary Undergraduate Training in Surgical Techniques.

    ERIC Educational Resources Information Center

    Whittick, William G.

    1978-01-01

    The undergraduate surgery course of the Faculty of Veterinary Medicine and Animal Science, Universiti Pertanian Malaysia, is described with focus on its experential method of teaching surgical techniques. Also discussed are the benefits of veterinary school cooperation with a large city Society for the Prevention of Cruelty to Animals (SPCA). (JMD)

  13. Innovative Surgical Management of the Synovial Chondromatosis of Temporo-Mandibular Joints: Highly Conservative Surgical Technique.

    PubMed

    Ionna, Franco; Amantea, Massimiliano; Mastrangelo, Filiberto; Ballini, Andrea; Maglione, Maria Grazia; Aversa, Corrado; De Cecio, Rossella; Russo, Daniela; Marrelli, Massimo; Tatullo, Marco

    2016-07-01

    Synovial chondromatosis (SC) is an uncommon disease characterized by a benign nodular cartilaginous proliferation arising from the joint synovium, bursae, or tendon sheaths. Although the temporomandibular joint is rarely affected by neoplastic lesions, SC is the most common neoplastic lesion of this joint. The treatment of this disease consists in the extraoral surgery with a wide removal of the lesion; in this study, the authors described a more conservative intraoral surgical approach. Patient with SC of temporomandibular joint typically refer a limitation in the mouth opening, together with a persistent not physiological mandibular protrusion and an appearance of a neoformation located at the right preauricular region: the authors reported 1 scholar patient. After biopsy of the neoformation, confirming the synovial chondromatosis, the patient underwent thus to the surgical excision of the tumor, via authors' conservative transoral approach, to facilitate the enucleation of the neoformation. The mass fully involved the pterygo-maxillary fossa with involvement of the parotid lodge and of the right TMJ: this multifocal extension suggested for a trans-oral surgical procedure, in the light of the suspicion of a possible malignant nature of the neoplasm. Our intraoral conservative approach to surgery is aimed to reduce the presence of unaesthetic scars in preauricular and facial regions, with surgical results undoubtedly comparable to the traditional surgical techniques much more aggressive. Our technique could be a valid, alternative, and safe approach to treat this rare and complex kind of oncological disease.

  14. Optimization and surgical design for applications in pediatric cardiology

    NASA Astrophysics Data System (ADS)

    Marsden, Alison; Bernstein, Adam; Taylor, Charles; Feinstein, Jeffrey

    2007-11-01

    The coupling of shape optimization to cardiovascular blood flow simulations has potential to improve the design of current surgeries and to eventually allow for optimization of surgical designs for individual patients. This is particularly true in pediatric cardiology, where geometries vary dramatically between patients, and unusual geometries can lead to unfavorable hemodynamic conditions. Interfacing shape optimization to three-dimensional, time-dependent fluid mechanics problems is particularly challenging because of the large computational cost and the difficulty in computing objective function gradients. In this work a derivative-free optimization algorithm is coupled to a three-dimensional Navier-Stokes solver that has been tailored for cardiovascular applications. The optimization code employs mesh adaptive direct search in conjunction with a Kriging surrogate. This framework is successfully demonstrated on several geometries representative of cardiovascular surgical applications. We will discuss issues of cost function choice for surgical applications, including energy loss and wall shear stress distribution. In particular, we will discuss the creation of new designs for the Fontan procedure, a surgery done in pediatric cardiology to treat single ventricle heart defects.

  15. The posterolateral corner: surgical approach and technique overview.

    PubMed

    Dickens, Jonathan F; Kilcoyne, Kelly; Kluk, Matthew; Rue, John-Paul

    2011-09-01

    Injuries to the posterolateral corner (PLC) of the knee can lead to profound knee instability, especially when combined with anterior cruciate or posterior cruciate ligament injury. With increased recognition of this injury, as well as improved understanding of the pathoanatomy, surgical treatment of these injuries has evolved in favor of acute treatment including reconstructive techniques to minimize recurrent laxity and allow for early rehabilitation. This article describes the approach to the PLC and the technique for figure of 8 reconstruction.

  16. Standardization of surgical techniques used in facial bone contouring.

    PubMed

    Lee, Tae Sung

    2015-12-01

    Since the introduction of facial bone contouring surgery for cosmetic purposes, various surgical methods have been used to improve the aesthetics of facial contours. In general, by standardizing the surgical techniques, it is possible to decrease complication rates and achieve more predictable surgical outcomes, thereby increasing patient satisfaction. The technical strategies used by the author to standardize facial bone contouring procedures are introduced here. The author uses various pre-manufactured surgical tools and hardware for facial bone contouring. During a reduction malarplasty or genioplasty procedure, double-bladed reciprocating saws and pre-bent titanium plates customized for the zygomatic body, arch and chin are used. Various guarded oscillating saws are used for mandibular angloplasty. The use of double-bladed saws and pre-bent plates to perform reduction malarplasty reduces the chances of post-operative asymmetry or under- or overcorrection of the zygoma contours due to technical faults. Inferior alveolar nerve injury and post-operative jawline asymmetry or irregularity can be reduced by using a guarded saw during mandibular angloplasty. For genioplasty, final placement of the chin in accordance with preoperative quantitative analysis can be easily performed with pre-bent plates, and a double-bladed saw allows more procedural accuracy during osteotomies. Efforts by the surgeon to avoid unintentional faults are key to achieving satisfactory results and reducing the incidence of complications. The surgical techniques described in this study in conjunction with various in-house surgical tools and modified hardware can be used to standardize techniques to achieve aesthetically gratifying outcomes.

  17. Standardization of surgical techniques used in facial bone contouring.

    PubMed

    Lee, Tae Sung

    2015-12-01

    Since the introduction of facial bone contouring surgery for cosmetic purposes, various surgical methods have been used to improve the aesthetics of facial contours. In general, by standardizing the surgical techniques, it is possible to decrease complication rates and achieve more predictable surgical outcomes, thereby increasing patient satisfaction. The technical strategies used by the author to standardize facial bone contouring procedures are introduced here. The author uses various pre-manufactured surgical tools and hardware for facial bone contouring. During a reduction malarplasty or genioplasty procedure, double-bladed reciprocating saws and pre-bent titanium plates customized for the zygomatic body, arch and chin are used. Various guarded oscillating saws are used for mandibular angloplasty. The use of double-bladed saws and pre-bent plates to perform reduction malarplasty reduces the chances of post-operative asymmetry or under- or overcorrection of the zygoma contours due to technical faults. Inferior alveolar nerve injury and post-operative jawline asymmetry or irregularity can be reduced by using a guarded saw during mandibular angloplasty. For genioplasty, final placement of the chin in accordance with preoperative quantitative analysis can be easily performed with pre-bent plates, and a double-bladed saw allows more procedural accuracy during osteotomies. Efforts by the surgeon to avoid unintentional faults are key to achieving satisfactory results and reducing the incidence of complications. The surgical techniques described in this study in conjunction with various in-house surgical tools and modified hardware can be used to standardize techniques to achieve aesthetically gratifying outcomes. PMID:26346781

  18. Surgical Approaches Based on Biological Objectives: GTR versus GBR Techniques

    PubMed Central

    Pagni, Giorgio; Rasperini, Giulio

    2013-01-01

    Guided tissue regenerative (GTR) therapies are performed to regenerate the previously lost tooth supporting structure, thus maintaining the aesthetics and masticatory function of the available dentition. Alveolar ridge augmentation procedures (GBR) intend to regain the alveolar bone lost following tooth extraction and/or periodontal disease. Several biomaterials and surgical approaches have been proposed. In this paper we report biomaterials and surgical techniques used for periodontal and bone regenerative procedures. Particular attention will be adopted to highlight the biological basis for the different therapeutic approaches. PMID:23843792

  19. Multiple advanced surgical techniques to treat acquired seminal duct obstruction

    PubMed Central

    Jiang, Hong-Tao; Yuan, Qian; Liu, Yu; Liu, Zeng-Qin; Zhou, Zhen-Yu; Xiao, Ke-Feng; Yang, Jiang-Gen

    2014-01-01

    The aim of this study was to evaluate the outcomes of multiple advanced surgical treatments (i.e. microsurgery, laparoscopic surgery and endoscopic surgery) for acquired obstructive azoospermia. We analyzed the surgical outcomes of 51 patients with suspected acquired obstructive azoospermia consecutively who enrolled at our center between January 2009 and May 2013. Modified vasoepididymostomy, laparoscopically assisted vasovasostomy and transurethral incision of the ejaculatory duct with holmium laser were chosen and performed based on the different obstruction sites. The mean postoperative follow-up time was 22 months (range: 9 months to 52 months). Semen analyses were initiated at four postoperative weeks, followed by trimonthly (months 3, 6, 9 and 12) semen analyses, until no sperm was found at 12 months or until pregnancy was achieved. Patency was defined as >10,000 sperm ml−1 of semen. The obstruction sites, postoperative patency and natural pregnancy rate were recorded. Of 51 patients, 47 underwent bilateral or unilateral surgical reconstruction; the other four patients were unable to be treated with surgical reconstruction because of pelvic vas or intratesticular tubules obstruction. The reconstruction rate was 92.2% (47/51), and the patency rate and natural pregnancy rate were 89.4% (42/47) and 38.1% (16/42), respectively. No severe complications were observed. Using multiple advanced surgical techniques, more extensive range of seminal duct obstruction was accessible and correctable; thus, a favorable patency and pregnancy rate can be achieved. PMID:25337841

  20. Halstedian technique revisited. Innovations in teaching surgical skills.

    PubMed

    Barnes, R W; Lang, N P; Whiteside, M F

    1989-07-01

    This paper reviews the laboratory models used to teach fundamental surgical skills in our general surgery residency. The laboratory modules allow supervision and self-instruction, practice, and videotape monitoring of the following techniques: skin incision, suturing, knot tying, hemostasis, vascular anastomosis, and intestinal anastomosis. Pigs' feet simulate human skin for exercises in skin incision, lesion excision, suturing, and basic plastic surgical techniques. Latex tubing and penrose drains allow experience in suturing, knot tying, and hemostasis. Polytetrafluoroethylene vascular prostheses permit quantification of the precision of needle passage and suturing by measurement of leakage of water through a vascular anastomosis. Reconstituted, lyophilized, irradiated bovine arteries and ileum provide models of biologic tissue for creating handsewn vascular anastomoses and sutured or stapled gastrointestinal anastomoses. A headlamp videocamera allows unobstructive recording of the resident's technical performance and provides subsequent visual feedback for self-improvement when compared to reference instructional videotapes. We feel that these innovations may enhance surgical dexterity of residents without the need for animal sacrifice. Our goal is to foreshorten the learning curve for basic surgical skills and improve performance in the clinical operating room.

  1. [Pictures balance for optimal surgical management of pelvic endometriosis. Imaging and surgery of endometriosis].

    PubMed

    Leroy, A; Garabedian, C; Fourquet, T; Azaïs, H; Merlot, B; Collinet, P; Rubod, C

    2016-03-01

    Endometriosis is a frequent benign pathology that is found in 10-15% of women and in 20% of infertile women. It has an impact on fertility, but also in everyday life. If medical treatment fails, surgical treatment can be offered to the patient. To provide adequate treatment and give clearer information to patients, it seems essential to achieve an optimal preoperative imaging assessment. Thus, the aim of this work is to define the information expected by the surgeon and the indications of each imaging test for each compartment of the pelvis, allowing an ideal surgical management of pelvic endometriosis. We will not discuss imaging techniques' principles and we will not develop the indications and surgical techniques. PMID:26874665

  2. Biliopancreatic Diversion with Duodenal Switch: Surgical Technique and Perioperative Care.

    PubMed

    Biertho, Laurent; Lebel, Stéfane; Marceau, Simon; Hould, Frédéric-Simon; Julien, François; Biron, Simon

    2016-08-01

    The goal of this article is to present an overview of selection criteria, surgical technique, and perioperative outcomes of biliopancreatic diversion with duodenal switch. The standard follow-up requirements, including vitamin supplementation, and long-term risks associated with metabolic surgery are also discussed. Most of the data reported here are based on the authors' experience with 4000 biliopancreatic diversions with duodenal switch performed in their institution since 1990.

  3. Hemorrhage after tonsillectomy: does the surgical technique really matter?

    PubMed

    Gysin, Claudine; Dulguerov, Pavel

    2013-01-01

    A thorough review of the publications on surgical techniques used for tonsillectomy is provided, emphasizing randomized studies and meta-analysis. In the assessment of the data it is important to clearly define and categorize the types of posttonsillectomy bleeding (PTB), as well as the various factors that have been associated with increased PTB. In recent audits of a large number of tonsillectomies, the PTB rates seem to concur: 1% early and 2.5% delayed PTB; 10% anamnestic, 2% objective, and 2% re-operation PTB. Objective PTB rates beyond 10% should require an audit. The bipolar technique seems associated with the least early PTB, while the cold technique is associated with the least delayed PTB. Because of the lack of large well-conducted randomized trials, it is difficult to conclude which technique is the best. With electrocautery techniques, the current power should be adjusted to the minimal level providing hemostasis. Surgical techniques for tonsillectomy that should probably be abandoned include monopolar electrocautery, Coblation, various lasers, and the harmonic scalpel. Vessel-sealing systems might hold promise and deserve further evaluation. Tonsillotomy might be associated with less postoperative pain, but the hemorrhagic advantage in randomized studies is not obvious. Tonsil regrowth rates and efficacy to treat obstruction need also further evaluation.

  4. AUDIOVISUAL RESOURCES ON THE TEACHING PROCESS IN SURGICAL TECHNIQUE

    PubMed Central

    PUPULIM, Guilherme Luiz Lenzi; IORIS, Rafael Augusto; GAMA, Ricardo Ribeiro; RIBAS, Carmen Australia Paredes Marcondes; MALAFAIA, Osvaldo; GAMA, Mirnaluci

    2015-01-01

    Background: The development of didactic means to create opportunities to permit complete and repetitive viewing of surgical procedures is of great importance nowadays due to the increasing difficulty of doing in vivo training. Thus, audiovisual resources favor the maximization of living resources used in education, and minimize problems arising only with verbalism. Aim: To evaluate the use of digital video as a pedagogical strategy in surgical technique teaching in medical education. Methods: Cross-sectional study with 48 students of the third year of medicine, when studying in the surgical technique discipline. They were divided into two groups with 12 in pairs, both subject to the conventional method of teaching, and one of them also exposed to alternative method (video) showing the technical details. All students did phlebotomy in the experimental laboratory, with evaluation and assistance of the teacher/monitor while running. Finally, they answered a self-administered questionnaire related to teaching method when performing the operation. Results: Most of those who did not watch the video took longer time to execute the procedure, did more questions and needed more faculty assistance. The total exposed to video followed the chronology of implementation and approved the new method; 95.83% felt able to repeat the procedure by themselves, and 62.5% of those students that only had the conventional method reported having regular capacity of technique assimilation. In both groups mentioned having regular difficulty, but those who have not seen the video had more difficulty in performing the technique. Conclusion: The traditional method of teaching associated with the video favored the ability to understand and transmitted safety, particularly because it is activity that requires technical skill. The technique with video visualization motivated and arouse interest, facilitated the understanding and memorization of the steps for procedure implementation, benefiting the

  5. Surgical technique for allogeneic uterus transplantation in macaques

    PubMed Central

    Obara, Hideaki; Kisu, Iori; Kato, Yojiro; Yamada, Yohei; Matsubara, Kentaro; Emoto, Katsura; Adachi, Masataka; Matoba, Yusuke; Umene, Kiyoko; Nogami, Yuya; Banno, Kouji; Tsuchiya, Hideaki; Itagaki, Iori; Kawamoto, Ikuo; Nakagawa, Takahiro; Ishigaki, Hirohito; Itoh, Yasushi; Ogasawara, Kazumasa; Saiki, Yoko; Sato, Shin-ichi; Nakagawa, Kenshi; Shiina, Takashi; Aoki, Daisuke; Kitagawa, Yuko

    2016-01-01

    No study has reported an animal model of uterus transplantation (UTx) using cynomolgus macaques. We aimed to establish a surgical technique of allogeneic UTx assuming the recovery of a uterus from a deceased donor in cynomolgus macaques. Four allogeneic UTxs were performed in female cynomolgus macaques. Donor surgeries comprised en bloc recovery of organs with iliac vessels on both sides, and/or abdominal aorta/vena cava after sufficient perfusion from one femoral artery or external iliac artery. Before perfusion, 150 mL of whole blood was obtained from the donor for subsequent blood transfusion to the recipient. Four uterine grafts were orthotopically transplanted to recipients. End-to-side anastomosis was performed to the iliac vessels on one side in case 1 and iliac vessels on both sides in case 2; aorto-aorto/cavo-caval anastomosis was performed in cases 3 and 4. Arterial blood flow of the uterine grafts was determined by intraoperative indocyanine green (ICG) angiography. ICG angiography results showed sufficient blood flow to all uterine grafts, and anaemia did not progress. Under appropriate immune suppression, all recipients survived for more than 90 days post-transplantation, without any surgical complications. We describe a surgical technique for allogeneic UTx in cynomolgus macaques. PMID:27786258

  6. Open, laparoscopic and robotic radical prostatectomy: optimizing the surgical approach.

    PubMed

    Bivalacqua, Trinity J; Pierorazio, Phillip M; Su, Li-Ming

    2009-09-01

    As advances in the understanding of prostatic anatomy led to improvements in functional and oncologic outcomes after prostatectomy of the past few decades, advances in technology and surgical technique have made minimally-invasive prostate surgery a reality. Today patients diagnosed with clinically localized prostate cancer have more surgical treatment options than in the past including open, laparoscopic and robot-assisted laparoscopic radical prostatectomy. Advantages and disadvantages exist for each modality and lead to subtle differences in the technical execution of the procedure. Evidence from centers of excellence and from experienced surgeons demonstrates that both laparoscopic and robotic-assisted laparoscopic radical prostatectomy appear to be comparable to outcomes achieved with open radical retropubic prostatectomy series. Individual surgeon skill, experience and clinical judgment are likely the stronger predictors of outcome rather than the technique chosen. However, learning curves, oncologic outcomes and cost-efficacy remain important considerations in the dissemination of minimally-invasive prostate surgery. A greater appreciation of the periprostatic anatomy and further modification of surgical technique will result in continued improvement in functional outcomes and oncological control for patients undergoing radical prostatectomy, whether by open or minimally-invasive surgery. PMID:19286370

  7. Surgical technique for treatment of recalcitrant adductor longus tendinopathy.

    PubMed

    Gill, Thomas J; Carroll, Kaitlin M; Makani, Amun; Wall, Andrew J; Dumont, Guillaume D; Cohn, Randy M

    2014-04-01

    Chronic groin pain in the athlete can be a difficult problem to manage. Adductor dysfunction is the most common cause of groin pain in athletes, with the adductor longus being the tendon most commonly involved. The most reproducible finding for adductor longus tendinopathy is tenderness along the tendon with passive abduction and resisted hip adduction in extension. Magnetic resonance imaging and injection of a corticosteroid and anesthetic into the proximal muscle-tendon junction are both helpful in confirming the diagnosis. Nonoperative treatment may consist of protected weight bearing, ice application, ultrasonography, electrical stimulation, and gentle stretching with progressive strengthening. However, nonoperative management is not always successful. In these instances, surgical treatment can be quite effective. We present the indications, surgical technique, and rehabilitation protocol of adductor tenotomy for chronic tendinopathy. This can prove a useful tool for the treatment of recalcitrant groin pain attributable to the adductor longus. PMID:24904780

  8. Surgical technique for treatment of recalcitrant adductor longus tendinopathy.

    PubMed

    Gill, Thomas J; Carroll, Kaitlin M; Makani, Amun; Wall, Andrew J; Dumont, Guillaume D; Cohn, Randy M

    2014-04-01

    Chronic groin pain in the athlete can be a difficult problem to manage. Adductor dysfunction is the most common cause of groin pain in athletes, with the adductor longus being the tendon most commonly involved. The most reproducible finding for adductor longus tendinopathy is tenderness along the tendon with passive abduction and resisted hip adduction in extension. Magnetic resonance imaging and injection of a corticosteroid and anesthetic into the proximal muscle-tendon junction are both helpful in confirming the diagnosis. Nonoperative treatment may consist of protected weight bearing, ice application, ultrasonography, electrical stimulation, and gentle stretching with progressive strengthening. However, nonoperative management is not always successful. In these instances, surgical treatment can be quite effective. We present the indications, surgical technique, and rehabilitation protocol of adductor tenotomy for chronic tendinopathy. This can prove a useful tool for the treatment of recalcitrant groin pain attributable to the adductor longus.

  9. Surgical techniques and radiological findings of meniscus allograft transplantation.

    PubMed

    Lee, Hoseok; Lee, Sang Yub; Na, Young Gon; Kim, Sung Kwan; Yi, Jae Hyuck; Lim, Jae Kwang; Lee, So Mi

    2016-08-01

    Meniscus allograft transplantation has been performed over the past 25 years to relieve knee pain and improve knee function in patients with an irreparable meniscus injury. The efficacy and safety of meniscus allograft transplantation have been established in numerous experimental and clinical researches. However, there is a lack of reviews to aid radiologists who are routinely interpreting images and evaluating the outcome of the procedures, and also meniscus allograft transplantation is not widely performed in most hospitals. This review focuses on the indications of the procedure, the different surgical techniques used for meniscus allograft transplantation according to the involvement of the lateral and medial meniscus, and the associated procedures. The postoperative radiological findings and surgical complications of the meniscus allograft transplantation are also described in detail.

  10. The anatomic coracoclavicular ligament reconstruction: surgical technique and indications.

    PubMed

    Carofino, Brad C; Mazzocca, Augustus D

    2010-03-01

    The anatomic coracoclavicular ligament reconstruction (ACCR) is a surgical procedure to address acriomioclavicular joint instability. The coracoclavicular ligaments are reconstructed using a semitendinosus allograft passed beneath the coracoid and through bone tunnels in the clavicle. The graft is secured with interference screw fixation, and the acromioclavicular joint is retained. Here we describe the authors' surgical technique, indications, and rehabilitation protocol. Also, a preliminary case series of seventeen patients is presented. Patients demonstrated significant improvement in pain levels and function. The mean ASES score increased from 52 preoperatively to 92. The Constant Murley rose from 66.6 to 94.7. There were three failures in this series, and two required revision surgery. PMID:20188267

  11. Surgical repair of complete atrioventricular defect (Nunn technique).

    PubMed

    El-Rassi, Issam; Charafeddine, Fatimah; Tabbakh, Anas; Aboutaka, Mohammad; Khater, Daniele; Arabi, Mariam; Bitar, Fadi

    2015-01-01

    Two procedures have been traditionally used for the surgical repair of complete atrioventricular canal. The single-patch technique includes the division of valve leaflets, and the use of one patch to close the ventricular and the atrial septal defects, whereas the double-patch technique uses two separate patches, without the division of the bridging leaflets. Between 1997 and 2007, another technique emerged, the modified single-patch technique, or the 'Australian' technique, whereby the ventricular septal defect (VSD) is closed by the direct apposition of the bridging leaflets against the crest of the defect. Because of the absence of the ventricular septal patch, concerns have been raised about the possible left ventricular outflow tract obstruction (LVOTO), or atrioventricular valve (AVV) distortion, especially in case of a deep VSD, or if the defect extends superiorly. The results of the modified single-patch technique in terms of mortality, immediate and long-term AVV function and LVOTO have been similar to the standard techniques in most reports. This article will describe in detail the operative technique and review the relevant literature. PMID:26443542

  12. Surgical techniques: robot-assisted laparoscopic colposacropexy with the da Vinci(®) surgical system.

    PubMed

    Matthews, Catherine A

    2009-03-01

    Colposacropexy is the gold-standard operation for repair of apical vaginal support defects. While it is feasible to perform this operation using conventional laparoscopic techniques, a limited number of surgeons have mastered the advanced minimally invasive skills that are required. Introduction of the da Vinci(®) robotic system with instruments that have improved dexterity and precision and a camera system with three-dimensional imaging presents an opportunity for more surgeons treating women with pelvic organ prolapse to perform the procedure laparoscopically. This paper will outline a technique that is exactly modeled after the open procedure for completion of a robotic-assisted colposacropexy using the da Vinci(®) surgical system. PMID:27628451

  13. An artificial system for selecting the optimal surgical team

    PubMed Central

    Saberi, Nahid; Mahvash, Mohsen; Zenati, Marco

    2016-01-01

    We introduce an intelligent system to optimize a team composition based on the team’s historical outcomes and apply this system to compose a surgical team. The system relies on a record of the procedures performed in the past. The optimal team composition is the one with the lowest probability of unfavorable outcome. We use the theory of probability and the inclusion exclusion principle to model the probability of team outcome for a given composition. A probability value is assigned to each person of database and the probability of a team composition is calculated from them. The model allows to determine the probability of all possible team compositions even if there is no recoded procedure for some team compositions. From an analytical perspective, assembling an optimal team is equivalent to minimizing the overlap of team members who have a recurring tendency to be involved with procedures of unfavorable results. A conceptual example shows the accuracy of the proposed system on obtaining the optimal team. PMID:26736239

  14. Role of Recipient-site Preparation Techniques and Post-operative Wound Dressing in the Surgical Management of Vitiligo

    PubMed Central

    Al-Hadidi, Nour; Griffith, James L; Al-Jamal, Mohammed S; Hamzavi, Iltefat

    2015-01-01

    Vitiligo is an acquired skin disorder characterized by the destruction of melanocytes resulting in achromic macules and patches involving the affected skin. Multiple methods of treatments have emerged to manage vitiligo, including medical and surgical techniques. Among the surgical techniques described in the management of vitiligo are minipunch grafting, split-thickness skin grafting, hair follicle transplantation, suction blister grafting, and cultured and non-cultured autologous melanocyte transplantation. However, prior to grafting optimal recipient-site preparation is needed for graft survival and successful repigmentation outcomes. Similarly, post-operative care of the recipient site is vital to yielding a viable graft irrespective of the transplantation technique employed. This article reviews the multiple methods employed to prepare the recipient site in vitiligo surgeries and the post-surgical conditions which optimize graft viability. A pubmed search was conducted utilizing the key words listed below. PMID:26157306

  15. Polynomial optimization techniques for activity scheduling. Optimization based prototype scheduler

    NASA Technical Reports Server (NTRS)

    Reddy, Surender

    1991-01-01

    Polynomial optimization techniques for activity scheduling (optimization based prototype scheduler) are presented in the form of the viewgraphs. The following subject areas are covered: agenda; need and viability of polynomial time techniques for SNC (Space Network Control); an intrinsic characteristic of SN scheduling problem; expected characteristics of the schedule; optimization based scheduling approach; single resource algorithms; decomposition of multiple resource problems; prototype capabilities, characteristics, and test results; computational characteristics; some features of prototyped algorithms; and some related GSFC references.

  16. Orthodontic microsurgery: a new surgically guided technique for dental movement.

    PubMed

    Vercellotti, Tomaso; Podesta, Andrea

    2007-08-01

    Eight patients with malocclusions were treated with a new orthodontic-surgical technique that reduces the duration of treatment compared to conventional techniques. The monocortical tooth dislocation and ligament distraction (MTDLD) technique combines two different dental movements that work separately but simultaneously on opposite root surfaces. On the root surface corresponding to the direction of movement, vertical and horizontal microsurgical corticotomies are performed around each tooth root with a piezosurgical microsaw to eliminate cortical bone resistance. The immediate application of strong biomechanical forces produces rapid dislocation of the root and the cortical bone together. On the root surface opposite the direction of movement, the force of dislocation produces rapid distraction of ligament fibers. During the osteogenic process that follows, application of normal orthodontic biomechanics achieves the final tooth movement. All eight patients underwent periodontal and radiologic examinations for more than 1 year after treatment. No periodontal defects were observed in any of the patients, including one with a severe malocclusion and a thin periodontal tissue biotype. Compared to traditional orthodontic therapy, the average treatment time with the MTDLD technique in the mandible and maxilla was reduced by 60% and 70%, respectively.

  17. THD Doppler procedure for hemorrhoids: the surgical technique.

    PubMed

    Ratto, C

    2014-03-01

    Transanal hemorrhoidal dearterialization (THD) is an effective treatment for hemorrhoidal disease. The ligation of hemorrhoidal arteries (called "dearterialization") can provide a significant reduction of the arterial overflow to the hemorrhoidal piles. Plication of the redundant rectal mucosa/submucosa (called "mucopexy") can provide a repositioning of prolapsing tissue to the anatomical site. In this paper, the surgical technique and perioperative patient management are illustrated. Following adequate clinical assessment, patients undergo THD under general or spinal anesthesia, in either the lithotomy or the prone position. In all patients, distal Doppler-guided dearterialization is performed, providing the selective ligation of hemorrhoidal arteries identified by Doppler. In patients with hemorrhoidal/muco-hemorrhoidal prolapse, the mucopexy is performed with a continuous suture including the redundant and prolapsing mucosa and submucosa. The description of the surgical procedure is complemented by an accompanying video (see supplementary material). In long-term follow-up, there is resolution of symptoms in the vast majority of patients. The most common complication is transient tenesmus, which sometimes can result in rectal discomfort or pain. Rectal bleeding occurs in a very limited number of patients. Neither fecal incontinence nor chronic pain should occur. Anorectal physiology parameters should be unaltered, and anal sphincters should not be injured by following this procedure. When accurately performed and for the correct indications, THD is a safe procedure and one of the most effective treatments for hemorrhoidal disease.

  18. Current techniques in surgical correction of congenital ptosis.

    PubMed

    Allard, Felicia D; Durairaj, Vikram D

    2010-04-01

    Ptosis refers to vertical narrowing of the palpebral fissure secondary to drooping of the upper eyelid to a lower than normal position. Ptosis is considered congenital if present at birth or if it is diagnosed within the first year of life. Correction of congenital ptosis is one of the most difficult challenges ophthalmologists face. Multiple surgical procedures are available including, frontalis sling, levator advancement, Whitnall sling, frontalis muscle flap, and Mullerectomy. Selection of one technique over another depends on the consideration of several factors including the surgeon experience, the degree of ptosis in the patient, as well as the degree of levator muscle function. Current recommendations for the correction of congential ptosis vary based on clinical presentation. Advantages and disadvantages of each of these procedures are presented with recommendations to avoid complications. PMID:20616918

  19. Indications and Specific Surgical Techniques in Crohn's Disease

    PubMed Central

    Seifarth, Claudia; Kreis, Martin E.; Gröne, Jörn

    2015-01-01

    Summary Background Crohn's disease (CD) as one of the major entities of chronic inflammatory bowel diseases can affect all segments of the gastrointestinal tract but occurs most often in the small bowel, the terminal ileum, the colon, and the rectum. Typical symptoms include tiredness, lower abdominal pain, fever, and diarrhea, which are initially treated by conservative measures. Most patients will eventually develop complications such as fistulas, abscesses, or strictures. Surgery is often unavoidable in these cases. Methods This review considers studies on the treatment of CD, published from 1979 up to now. The literature regarding the course, complications, and surgical therapy of CD was reviewed. Searches were performed in PubMed, using the following key words: CD, surgery, immunosuppression, guidelines, malnutrition as well as appropriate sub-items. In most cases the literature is limited to detailed information on specific therapeutic or diagnostic topics. Moreover, many studies are designed retrospectively and with a small number of patients. Additionally, our long-standing experience with patients suffering from CD is taken into consideration in this review. Results There is a wide variety of indications for surgery in CD which includes complications like strictures, fistulas and abscess formation, neoplasia, or refractoriness to medical therapy. The risk of developing complications is about 33% after 5 years, and 50% after 20 years. Furthermore, one-third of CD patients need surgical therapy within the first 5 years of diagnosis. The treatment requires close cooperation between gastroenterologists and surgeons. When indicated, surgery should be performed in a ‘conservative’ fashion, i.e. as limited as possible, in order to achieve the required result and to avoid small bowel syndrome. Conclusion This article provides a complete overview of indications and specific surgical treatment in patients with CD. Surgery is typically indicated when

  20. Refinement of a surgical technique using angulated needle holders and surgical instruments.

    PubMed

    Hodge, J

    1986-01-01

    Surgical techniques can be refined and dexterity improved by using angulated needle holders and instruments. This allows the surgeon to place his or her hand in the position of function while suturing either retrograde or antegrade, thus permitting flexion, extension, abduction, adduction, pronation and supination with circumduction to occur without restriction. Under normal circumstances abduction, pronation and extension are limited by anatomic factors, such as the greater mulitangular abutting the longer styloid process of the radius and the stronger ulnar collateral ligament restricting abduction. The chief indication for using angulated needle holders is in retrograde suturing, such as placing posterior row sutures in anastomosing blood vessels, intestine and the ureter. These instruments are not substitutes for straight needle holders but are chiefly an adjunct that permit the surgeon to perform movements with his hand at the wrist joint that are not allowed with the use of straight needle holders which require greater torque in performing operative procedures. They allow better exposure by improving visibility to the area being sutured since the surgeon is not looking down the barrel of the needle holder and has a clear unobstructed view. The instruments permit clamping and suturing of tissues and vessels in small deep wounds that do not readily admit nonangulated hemostats and needle holders, such as those in urologic and gynecologic operations. Instrument tying is easily accomplished because of the short shaft of the instrument, especially in plastic or surface surgical procedures. Furthermore, with angulation, one is able to grasp the needle holder between the thumb and volar aspect of the second and third digits, thus allowing easy retrograde movements that one experiences in grasping a thumb forceps. From the standpoint of medical egonometrics, hand fatigue is reduced since the needle holder does not have to be locked by closing the rings and engaging

  1. Through Knee Amputation: Technique Modifications and Surgical Outcomes

    PubMed Central

    Albino, Frank P; Seidel, Rachel; Brown, Benjamin J; Crone, Charles G

    2014-01-01

    Background Knee disarticulations (KD) are most commonly employed following trauma or tumor resection but represent less than 2% of all lower extremity amputations performed in the United States annually. KDs provide enhanced proprioception, a long lever arm, preservation of adductor muscle insertion, decreased metabolic cost of ambulation, and an end weight-bearing stump. The role for KDs in the setting of arterial insufficiency or overwhelming infection is less clear. The purpose of this study is to describe technique modifications and report surgical outcomes following KDs at a high-volume Limb Salvage Center. Methods A retrospective study of medical records for all patients who underwent a through-knee amputation performed by the senior author (C.E.A.) between 2004 and 2012 was completed. Medical records were reviewed to collect demographic, operative, and postoperative information for each of the patients identified. Results Between 2004 and 2012, 46 through-knee amputations for 41 patients were performed. The mean patient age was 68 and indications for surgery included infection (56%), arterial thrombosis (35%), and trauma (9%). Postoperative complications included superficial cellulitis (13%), soft tissue infection (4%), and flap ischemia (4%) necessitating one case of surgical debridement (4%) and four trans-femoral amputations (9%). 9 (22%) patients went on to ambulate. Postoperative ambulation was greatest in the traumatic cohort and for patients less than 50 years of age, P<0.05. Alternatively, diabetes mellitus and infection reduced the likelihood of postoperative ambulation, P<0.01. Conclusions Knee disarticulations are a safe and effective alternative to other lower extremity amputations when clinically feasible. For patient unlikely to ambulate, a through-knee amputation maximizes ease of transfers, promotes mobility by providing a counterbalance, and eliminates the potential for knee flexion contracture with subsequent skin breakdown. PMID:25276650

  2. A survey of compiler optimization techniques

    NASA Technical Reports Server (NTRS)

    Schneck, P. B.

    1972-01-01

    Major optimization techniques of compilers are described and grouped into three categories: machine dependent, architecture dependent, and architecture independent. Machine-dependent optimizations tend to be local and are performed upon short spans of generated code by using particular properties of an instruction set to reduce the time or space required by a program. Architecture-dependent optimizations are global and are performed while generating code. These optimizations consider the structure of a computer, but not its detailed instruction set. Architecture independent optimizations are also global but are based on analysis of the program flow graph and the dependencies among statements of source program. A conceptual review of a universal optimizer that performs architecture-independent optimizations at source-code level is also presented.

  3. Lumbar hernia: surgical anatomy, embryology, and technique of repair.

    PubMed

    Stamatiou, Dimitrios; Skandalakis, John E; Skandalakis, Lee J; Mirilas, Petros

    2009-03-01

    Lumbar hernia is the protrusion of intraperitoneal or extraperitoneal contents through a defect of the posterolateral abdominal wall. Barbette was the first, in 1672, to suggest the existence of lumbar hernias. The first case was reported by Garangeot in 1731. Petit and Grynfeltt delineated the boundaries of the inferior and superior lumbar triangles in 1783 and 1866, respectively. These two anatomical sites account for about 95 per cent of lumbar hernias. Approximately 20 per cent of lumbar hernias are congenital. The rest are either primarily or secondarily acquired. The most common cause of primarily acquired lumbar hernias is increased intra-abdominal pressure. Secondarily acquired lumbar hernias are associated with prior surgical incisions, trauma, and abscess formation. During embryologic development, weakening of the area of the aponeuroses of the layered abdominal muscles that derive from somitic mesoderm, which invades the somatopleure, may potentially lead to lumbar hernias. Repair of lumbar hernias should be performed as early as possible to avoid incarceration and strangulation. The classic repair technique uses the open approach, where closure of the defect is performed either directly or using prosthetic mesh. The laparoscopic approach, either transabdominal or extraperitoneal, is an alternative.

  4. LESS living donor nephrectomy: Surgical technique and results

    PubMed Central

    Alessimi, Abdullah; Adam, Emilie; Haber, Georges-Pascal; Badet, Lionel; Codas, Ricardo; Fehri, Hakim Fassi; Martin, Xavier; Crouzet, Sébastien

    2015-01-01

    Purpose: We present the findings of 50 patients undergoing pure trans-umbilical laparo-endoscopic single-site surgery (LESS) living donor nephrectomy (LDN), between February 2010 and May 2014. Materials and Methods: Laparo-endoscopic single-site surgery LDN was performed through an umbilical incision. Different trocars were used, namely Gelpoint (Applied Mιdical, Rancho Santa Margarita, CA) SILS port (Covidien, Hamilton, Bermuda), R-port (Olympus Surgical, Orangeburg, NY) and standard trocars, inserted through the same skin incision but using separate fascial punctures. The standard laparoscopic technique was employed. The kidney was pre-entrapped in a retrieval bag and extracted trans-umbilically. Data were collected prospectively including questionnaires containing patient reported oral pain medication duration and time to recovery. Results: LESS LDN was successful in all patients. Mean warm ischemia time was 6.2 min (3–15), mean procedure time was 233.2 min (172–300), and hospitalization stay was 3.94 days (3–7) with a visual analogue pain score at discharge of 1.32 (0–3). No intraoperative complications occurred. The mean time of oral pain medication was 8.72 days (1–20) and final scar length was 4.06 cm (3–5). Each allograft was functional. Conclusion: Although challenging, trans-umbilical LESS LDN seems to be feasible and safe. Hence, LESS has the potential to improve cosmetic results and decrease morbidity. PMID:26229326

  5. Bernese periacetabular osteotomy for hip dysplasia: Surgical technique and indications

    PubMed Central

    Kamath, Atul F

    2016-01-01

    For young, active patients with healthy hip cartilage, pelvic osteotomy is a surgical option in to address hip pain and to improve mechanical loading conditions related to dysplasia. Hip dysplasia may lead to arthrosis at an early age due to poor coverage of the femoral head and abnormal loading of the joint articulation. In patients with symptomatic dysplasia and closed triradiate cartilage (generally over age 10), including adolescents and young adults (generally up to around age 40), the Bernese periacetabular osteotomy (PAO) is a durable technique for addressing underlying structural deformity. The PAO involves a modified Smith-Petersen approach. Advantages of the Bernese osteotomy include preservation of the weight-bearing posterior column of the hemi-pelvis, preservation of the acetabular blood supply, maintenance of the hip abductor musculature, and the ability to effect powerful deformity correction about an ideal center of rotation. There is an increasing body of evidence that preservation of the native hip can be improved through pelvic osteotomy. In contrast to hip osteotomy and joint preservation, the role of total hip arthroplasty in young, active patients with correctable hip deformity remains controversial. Moreover, the durability of hip replacement in young patients is inherently limited. Pelvic osteotomy should be considered the preferred method to address correctable structural deformity of the hip in the young, active patient with developmental dysplasia. The Bernese PAO is technically demanding, yet offers reproducible results with good long-term survivorship in carefully selected patients with preserved cartilage and the ability to meet the demands of rehabilitation. PMID:27190755

  6. Periodontal plastic surgical technique for gingival fenestration closure.

    PubMed

    Peacock, M E; Mott, D A; Cuenin, M F; Hokett, S D; Fowler, E B

    2001-01-01

    Gingival fenestration is an opening through oral keratinized tissue, usually unattached, that is observed in thin gingiva with usually thick subgingival calculus deposits. This lesion is seen infrequently but may be more common than has been reported; lack of symptoms may inhibit patient awareness. Because surgical correction usually is not required, there are very few reports in the literature concerning this lesion. The following report describes a case of gingival fenestration and surgical treatment with a connective tissue/periosteal graft. PMID:12016683

  7. Lengthening of fourth brachymetatarsia by three different surgical techniques.

    PubMed

    Lee, W-C; Yoo, J H; Moon, J-S

    2009-11-01

    We carried out a retrospective study to assess the clinical results of lengthening the fourth metatarsal in brachymetatarsia in 153 feet of 106 patients (100 female, six males) using three different surgical techniques. In one group lengthening was performed by one-stage intercalary bone grafting secured by an intramedullary Kirschner-wire (45 feet, 35 patients). In the second group lengthening was obtained gradually using a mini-external fixator after performing an osteotomy with a saw (59 feet, 39 patients) and in the third group lengthening was achieved in a gradual manner using a mini-external fixator after undertaking an osteotomy using osteotome through pre-drilled holes (49 feet, 32 patients). The mean age of the patients was 26.3 years (13 to 48). Pre-operatively, the fourth ray of the bone-graft group was longer than that of other two groups (p < 0.000). The clinical outcome was compared in the three groups. The mean follow-up was 22 months (7 to 55). At final follow-up, the mean lengthening in the bone-graft group was 13.9 mm (3.5 to 23.0, 27.1%) which was less than that obtained in the saw group with a mean of 17.8 mm (7.0 to 33.0, 29.9%) and in the pre-drilled osteotome group with a mean of 16.8 mm (6.5 to 28.0, 29.4%, p = 0.001). However, the mean time required for retention of the fixation in the bone-graft group was the shortest of the three groups. Patients were dissatisfied with the result for five feet (11.1%) in the bone-graft group, eight (13.6%) in the saw group and none in the pre-drilled osteotomy group (p < 0.000). The saw group included eight feet with failure of bone formation after surgery. Additional operations were performed in 20 feet because of stiffness (n = 7, all groups), failure of bone formation (n = 4, saw group), skin maceration (n = 4, bone-graft group), malunion (n = 4, bone-graft and saw groups) and breakage of the external fixator (n = 1, saw group). We conclude that the gradual lengthening by distraction osteogenesis after

  8. Optimization techniques for integrating spatial data

    USGS Publications Warehouse

    Herzfeld, U.C.; Merriam, D.F.

    1995-01-01

    Two optimization techniques ta predict a spatial variable from any number of related spatial variables are presented. The applicability of the two different methods for petroleum-resource assessment is tested in a mature oil province of the Midcontinent (USA). The information on petroleum productivity, usually not directly accessible, is related indirectly to geological, geophysical, petrographical, and other observable data. This paper presents two approaches based on construction of a multivariate spatial model from the available data to determine a relationship for prediction. In the first approach, the variables are combined into a spatial model by an algebraic map-comparison/integration technique. Optimal weights for the map comparison function are determined by the Nelder-Mead downhill simplex algorithm in multidimensions. Geologic knowledge is necessary to provide a first guess of weights to start the automatization, because the solution is not unique. In the second approach, active set optimization for linear prediction of the target under positivity constraints is applied. Here, the procedure seems to select one variable from each data type (structure, isopachous, and petrophysical) eliminating data redundancy. Automating the determination of optimum combinations of different variables by applying optimization techniques is a valuable extension of the algebraic map-comparison/integration approach to analyzing spatial data. Because of the capability of handling multivariate data sets and partial retention of geographical information, the approaches can be useful in mineral-resource exploration. ?? 1995 International Association for Mathematical Geology.

  9. Software for the grouped optimal aggregation technique

    NASA Technical Reports Server (NTRS)

    Brown, P. M.; Shaw, G. W. (Principal Investigator)

    1982-01-01

    The grouped optimal aggregation technique produces minimum variance, unbiased estimates of acreage and production for countries, zones (states), or any designated collection of acreage strata. It uses yield predictions, historical acreage information, and direct acreage estimate from satellite data. The acreage strata are grouped in such a way that the ratio model over historical acreage provides a smaller variance than if the model were applied to each individual stratum. An optimal weighting matrix based on historical acreages, provides the link between incomplete direct acreage estimates and the total, current acreage estimate.

  10. Language abstractions for low level optimization techniques

    NASA Astrophysics Data System (ADS)

    Dévai, Gergely; Gera, Zoltán; Kelemen, Zoltán

    2012-09-01

    In case of performance critical applications programmers are often forced to write code at a low abstraction level. This leads to programs that are hard to develop and maintain because the program text is mixed up by low level optimization tricks and is far from the algorithm it implements. Even if compilers are smart nowadays and provide the user with many automatically applied optimizations, practice shows that in some cases it is hopeless to optimize the program automatically without the programmer's knowledge. A complementary approach is to allow the programmer to fine tune the program but provide him with language features that make the optimization easier. These are language abstractions that make optimization techniques explicit without adding too much syntactic noise to the program text. This paper presents such language abstractions for two well-known optimizations: bitvectors and SIMD (Single Instruction Multiple Data). The language features are implemented in the embedded domain specific language Feldspar which is specifically tailored for digital signal processing applications. While we present these language elements as part of Feldspar, the ideas behind them are general enough to be applied in other language definition projects as well.

  11. Systematic Review and Meta-Analysis of Surgical Zipper Technique versus Intracutaneous Sutures for the Closing of Surgical Incision

    PubMed Central

    Chen, Dezhi; Song, Jian; Zhao, Yong; Zheng, Xun; Yu, Aixi

    2016-01-01

    Background It is controversial whether surgical zipper technique (SZT), a non-invasive method of surgical wound closure, achieves a better outcome of incision healing than intracutaneous sutures (IS) in the surgery. This meta-analysis was performed to systematically analyze whether surgical zipper is superior to suture material for the incision closure. Methods Databases and reference lists were searched for randomized controlled trials (RCTs) comparing SZT with IS for the incision closure. Results Four RCTs with 678 patients were identified and analyzed. Compared with IS, SZT achieved similar incidence of postoperative complications, less time for incision closure, less cost of both surgeons’ time and operating room time, no need for removing sutures and more comfort for the patients. Besides, SZT achieved perfect aesthetic results in various types of incisions with the exception of those with substantial curvatures, those with secretions, in obese patients or those under high tension. Conclusion The non-invasive zipper technique may be a more attractive option of incision closure in a wide spectrum of surgical areas. PMID:27611083

  12. Sacroiliac screw fixation: A mini review of surgical technique

    PubMed Central

    Alvis-Miranda, Hernando Raphael; Farid-Escorcia, Hector; Alcalá-Cerra, Gabriel; Castellar-Leones, Sandra Milena; Moscote-Salazar, Luis Rafael

    2014-01-01

    The sacral percutaneous fixation has many advantages but can be associated with a significant exposure to X-ray radiation. Currently, sacroiliac screw fixation represents the only minimally invasive technique to stabilize the posterior pelvic ring. It is a technique that should be used by experienced surgeons. We present a practical review of important aspects of this technique. PMID:25336831

  13. Surgical Technique of Anterolateral Approach for Tibial Plateau Fracture.

    PubMed

    Wang, Peng-cheng; Ren, Dong; Zhou, Bing

    2015-11-01

    A 66-year-old woman had sustained crush injury 3 hours prior to her presentation to our hospital. The diagnosis was defined as lateral tibial plateau fracture of the right knee (Schatzker III). Supine position was set up and a pad was put under the affected hip. After sterilization of the surgical field the sterilized sheets were placed beneath the leg in order to be higher than the other side. A rolled sheet was put under the knee joint so that the knee joint was flexed around 30° to 40°. After the surgical field was draped the skin was incised. Iliotibial band was incised by blade (not by electrotomy) and sharp dissection was performed in the Gerdy's tubercle. Capsulotomy was made by cutting the tibial meniscal ligament. Then the meniscus was tagged superiorly and the articular surface was clearly visualized. A window was made in the lateral cortex beneath the plateau, so the impacted fragment was elevated through the window. The metaphyseal void was filled by bone allograft. The placement of the raft-screw plate must be ensured that the raft screws passing the plate could purchase the subchondral bone. After perfect placement of the plate was defined, the femoral distractor was removed and the knee joint was relaxed. It was ensured that the alignment of the lower leg was normal, and then the other screws were inserted. Following placing drainage in the wound the iliotibial band was closed and the subcutaneous soft tissue and skin were closed in layer. PMID:26791810

  14. Optimizing resources for the surgical care of children: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee consensus statement.

    PubMed

    Goldin, Adam B; Dasgupta, Roshni; Chen, Li Ern; Blakely, Martin L; Islam, Saleem; Downard, Cynthia D; Rangel, Shawn J; St Peter, Shawn D; Calkins, Casey M; Arca, Marjorie J; Barnhart, Douglas C; Saito, Jacqueline M; Oldham, Keith T; Abdullah, Fizan

    2014-05-01

    The United States' healthcare system is facing unprecedented pressures: the healthcare cost curve is not sustainable while the bar of standards and expectations for the quality of care continues to rise. Systems committed to the surgical treatment of children will likely require changes and reorganization. Regardless of these mounting pressures, hospitals must remain focused on providing the best possible care to each child at every encounter. Available clinical expertise and hospital resources should be optimized to match the complexity of the treated condition. Although precise criteria are lacking, there is a growing consensus that the optimal combination of clinical experience and hospital resources must be defined, and efforts toward this goal have been supported by the Regents of the American College of Surgeons, the members of the American Pediatric Surgical Association, and the Society for Pediatric Anesthesia (SPA) Board of Directors. The topic of optimizing outcomes and the discussion of the concepts involved have unfortunately become divisive. Our goals, therefore, are 1) to provide a review of the literature that can provide context for the discussion of regionalization, volume, and optimal resources and promote mutual understanding of these important terms, 2) to review the evidence that has been published to date in pediatric surgery associated with regionalization, volume, and resource, 3) to focus on a specific resource (anesthesia), and the association that this may have with outcomes, and 4) to provide a framework for future research and policy efforts.

  15. Combined operative technique with anterior surgical approach and video-assisted thoracoscopic surgical lobectomy for anterior superior sulcus tumours.

    PubMed

    Yokoyama, Yuhei; Chen, Fengshi; Aoyama, Akihiro; Sato, Toshihiko; Date, Hiroshi

    2014-11-01

    Video-assisted thoracoscopic surgery (VATS) has been widely used, but surgical resections of superior sulcus tumours remain challenging because of their anatomical location. For such cases, less-invasive procedures, such as the anterior transcervical-thoracic and transmanubrial approaches, have been widely performed because of their excellent visualization of the subclavian vessels. Recently, a combined operative technique with an anterior surgical approach and VATS for anterior superior sulcus tumours has been introduced. Herein, we report three cases of anterior superior sulcus tumours successfully resected by surgical approaches combined with a VATS-based lobectomy. In all cases, operability was confirmed by VATS, and upper lobectomies with hilar and mediastinal lymph node dissections were performed. Subsequently, dissections of the anterior inlet of the tumours were performed using the transmanubrial approach in two patients and the anterior trans-cervical-thoracic approach in one patient. Both approaches provided excellent access to the anterior inlet of the tumour and exposure of the subclavian vessels, resulting in radical resection of the tumour with concomitant resection of the surrounding anatomical structures, including the chest wall and vessels. In conclusion, VATS lobectomy combined with the anterior surgical approach might be an excellent procedure for the resection of anterior superior sulcus tumours.

  16. [Merle D'Aubigne's oblique proximal femoral osteotomy. Surgical technique].

    PubMed

    López Sosa, Francisco H; Valentín-Guerrero, Santiago; Miranda-López, Eduardo

    2008-01-01

    Proximal femoral osteotomy with the technique described by Merle D'AubignC and Valliant was used in the treatment of adult patients with osteoarthritis or idiopathic avascular necrosis. Dr. Antonio Flores applied this technique to children with subluxation and acetabular dysplasia, identified with exaggerated anteversion and valgus of the proximal femur. He reported correction of the deformity in 75% of patients. The purpose of this paper is to describe the technique, its indications and complications.

  17. Osteoradionecrosis of the temporal bone: a surgical technique of treatment

    SciTech Connect

    Ma, K.H.; Fagan, P.A.

    1988-05-01

    Osteoradionecrosis of the temporal bone is a well-documented complication of radiotherapy to the ear, with potentially lethal complications. Three cases of advanced disease, treated surgically, are presented. In two of these, subtotal petrosectomy with blind-sac closure of the external auditory canal was carried out via an anterior approach. The enclosed space was obliterated with pedicled temporalis muscle. Primary healing took place. One case was similarly obliterated using a prolonged posterior incision. The wound broke down, requiring a microvascular free flap for closure. Radiotherapy jeopardizes the viability of skin flaps. An anterior incision bases the flap behind on the occipital and postauricular arteries. When radiotherapy has been used, this incision has theoretical and practical advantages over a standard posterior incision.

  18. Automated optimization techniques for aircraft synthesis

    NASA Technical Reports Server (NTRS)

    Vanderplaats, G. N.

    1976-01-01

    Application of numerical optimization techniques to automated conceptual aircraft design is examined. These methods are shown to be a general and efficient way to obtain quantitative information for evaluating alternative new vehicle projects. Fully automated design is compared with traditional point design methods and time and resource requirements for automated design are given. The NASA Ames Research Center aircraft synthesis program (ACSYNT) is described with special attention to calculation of the weight of a vehicle to fly a specified mission. The ACSYNT procedures for automatically obtaining sensitivity of the design (aircraft weight, performance and cost) to various vehicle, mission, and material technology parameters are presented. Examples are used to demonstrate the efficient application of these techniques.

  19. Perineal hernia: surgical anatomy, embryology, and technique of repair.

    PubMed

    Stamatiou, Dimitrios; Skandalakis, John E; Skandalakis, Lee J; Mirilas, Petros

    2010-05-01

    Perineal hernia is the protrusion into the perineum of intraperitoneal or extraperitoneal contents through a congenital or acquired defect of the pelvic diaphragm. The first case was reported by de Garangeot in 1743. Perineal hernias may occur anteriorly or posteriorly to the superficial transverse perineal muscles. Congenital perineal hernia is a rare entity. Failure of regression of the peritoneal cul de sac of the embryo is considered a predisposing factor for hernia formation. Acquired perineal hernias are primary or secondary. Primarily acquired perineal hernias are caused by factors associated with increased intra-abdominal pressure. They are more common in females as a result of the broader female pelvis and the attenuation of the pelvic floor during pregnancy and childbirth. Secondarily acquired perineal hernias are incisional hernias associated with extensive pelvic operations such as abdominoperineal resection of the anorectum and pelvic exenteration. Pain in the perineal area, intestinal obstruction, topical skin erosion, and difficulty with urination necessitate the surgical repair of a perineal hernia. This can be accomplished through transabdominal, perineal, or combined abdominoperineal approaches. The defect in the muscles of the pelvic diaphragm may be closed either with direct suturing or by using autogenous tissues or synthetic mesh.

  20. Machine Learning Techniques in Optimal Design

    NASA Technical Reports Server (NTRS)

    Cerbone, Giuseppe

    1992-01-01

    Many important applications can be formalized as constrained optimization tasks. For example, we are studying the engineering domain of two-dimensional (2-D) structural design. In this task, the goal is to design a structure of minimum weight that bears a set of loads. A solution to a design problem in which there is a single load (L) and two stationary support points (S1 and S2) consists of four members, E1, E2, E3, and E4 that connect the load to the support points is discussed. In principle, optimal solutions to problems of this kind can be found by numerical optimization techniques. However, in practice [Vanderplaats, 1984] these methods are slow and they can produce different local solutions whose quality (ratio to the global optimum) varies with the choice of starting points. Hence, their applicability to real-world problems is severely restricted. To overcome these limitations, we propose to augment numerical optimization by first performing a symbolic compilation stage to produce: (a) objective functions that are faster to evaluate and that depend less on the choice of the starting point and (b) selection rules that associate problem instances to a set of recommended solutions. These goals are accomplished by successive specializations of the problem class and of the associated objective functions. In the end, this process reduces the problem to a collection of independent functions that are fast to evaluate, that can be differentiated symbolically, and that represent smaller regions of the overall search space. However, the specialization process can produce a large number of sub-problems. This is overcome by deriving inductively selection rules which associate problems to small sets of specialized independent sub-problems. Each set of candidate solutions is chosen to minimize a cost function which expresses the tradeoff between the quality of the solution that can be obtained from the sub-problem and the time it takes to produce it. The overall solution

  1. Spigelian hernia: surgical anatomy, embryology, and technique of repair.

    PubMed

    Skandalakis, Panagiotis N; Zoras, Odyseas; Skandalakis, John E; Mirilas, Petros

    2006-01-01

    Spigelian hernia (1-2% of all hernias) is the protrusion of preperitoneal fat, peritoneal sac, or organ(s) through a congenital or acquired defect in the spigelian aponeurosis (i.e., the aponeurosis of the transverse abdominal muscle limited by the linea semilunaris laterally and the lateral edge of the rectus muscle medially). Mostly, these hernias lie in the "spigelian hernia belt," a transverse 6-cm-wide zone above the interspinal plane; lower hernias are rare and should be differentiated from direct inguinal or supravescical hernias. Although named after Adriaan van der Spieghel, he only described the semilunar line (linea Spigeli) in 1645. Josef Klinkosch in 1764 first defined the spigelian hernia as a defect in the semilunar line. Defects in the aponeurosis of transverse abdominal muscle (mainly under the arcuate line and more often in obese individuals) have been considered as the principal etiologic factor. Pediatric cases, especially neonates and infants, are mostly congenital. Embryologically, spigelian hernias may represent the clinical outcome of weak areas in the continuation of aponeuroses of layered abdominal muscles as they develop separately in the mesenchyme of the somatopleura, originating from the invading and fusing myotomes. Traditionally, repair consists of open anterior herniorraphy, using direct muscle approximation, mesh, and prostheses. Laparoscopy, preferably a totally extraperitoneal procedure, or intraperitoneal when other surgical repairs are planned within the same procedure, is currently employed as an adjunct to diagnosis and treatment of spigelian hernias. Care must be taken not to create iatrogenic spigelian hernias when using laparoscopy trocars or classic drains in the spigelian aponeurosis.

  2. Robot assisted radical prostatectomy: how I do it. Part II: Surgical technique.

    PubMed

    Valdivieso, Roger F; Hueber, Pierre-Alain; Zorn, Kevin C

    2013-12-01

    The introduction of the "da Vinci Robotic Surgical System" (Intuitive Surgical, Sunnyvale, CA, USA) has been an important step towards a minimally invasive approach to radical prostatectomy. Technologic peculiarities, such as three-dimensional vision, wristed instrumentation with seven degrees of freedom of motion, lack of tremor, a 10x-magnification and a comfortable seated position for the surgeon has added value to the procedure for the surgeon and the patient. In this article, we describe the 9 step surgical technique for robot assisted radical prostatectomy (RARP) that is currently used in our institution (University of Montreal Hospital Center (CHUM) - Hopital St-Luc). We use the four-arm da Vinci Surgical System. Our experience with RARP is now over 250 cases with the senior surgeon having performed over 1200 RARPs and we have continually refined our technique to improve patient outcomes. PMID:24331353

  3. Novel surgical techniques, regenerative medicine, tissue engineering and innovative immunosuppression in kidney transplantation

    PubMed Central

    Nowacki, Maciej; Nazarewski, Łukasz; Tyloch, Dominik; Pokrywczyńska, Marta; Pietkun, Katarzyna; Jundziłł, Arkadiusz; Tyloch, Janusz; Habib, Samy L.; Drewa, Tomasz

    2016-01-01

    On the 60th anniversary of the first successfully performed renal transplantation, we summarize the historical, current and potential future status of kidney transplantation. We discuss three different aspects with a potential significant influence on kidney transplantation progress: the development of surgical techniques, the influence of regenerative medicine and tissue engineering, and changes in immunosuppression. We evaluate the standard open surgical procedures with modern techniques and compare them to less invasive videoscopic as well as robotic techniques. The role of tissue engineering and regenerative medicine as a potential method for future kidney regeneration or replacement and the interesting search for novel solutions in the field of immunosuppression will be discussed. After 60 years since the first successfully performed kidney transplantation, we can conclude that the greatest achievements are associated with the development of surgical techniques and with planned systemic immunosuppression. PMID:27695507

  4. Novel surgical techniques, regenerative medicine, tissue engineering and innovative immunosuppression in kidney transplantation

    PubMed Central

    Nowacki, Maciej; Nazarewski, Łukasz; Tyloch, Dominik; Pokrywczyńska, Marta; Pietkun, Katarzyna; Jundziłł, Arkadiusz; Tyloch, Janusz; Habib, Samy L.; Drewa, Tomasz

    2016-01-01

    On the 60th anniversary of the first successfully performed renal transplantation, we summarize the historical, current and potential future status of kidney transplantation. We discuss three different aspects with a potential significant influence on kidney transplantation progress: the development of surgical techniques, the influence of regenerative medicine and tissue engineering, and changes in immunosuppression. We evaluate the standard open surgical procedures with modern techniques and compare them to less invasive videoscopic as well as robotic techniques. The role of tissue engineering and regenerative medicine as a potential method for future kidney regeneration or replacement and the interesting search for novel solutions in the field of immunosuppression will be discussed. After 60 years since the first successfully performed kidney transplantation, we can conclude that the greatest achievements are associated with the development of surgical techniques and with planned systemic immunosuppression.

  5. Cache Energy Optimization Techniques For Modern Processors

    SciTech Connect

    Mittal, Sparsh

    2013-01-01

    and veterans in the field of cache power management. It will help graduate students, CAD tool developers and designers in understanding the need of energy efficiency in modern computing systems. Further, it will be useful for researchers in gaining insights into algorithms and techniques for micro-architectural and system-level energy optimization using dynamic cache reconfiguration. We sincerely believe that the ``food for thought'' presented in this book will inspire the readers to develop even better ideas for designing ``green'' processors of tomorrow.

  6. [NABARRA TECHNIQUE. POST-SURGICAL APPLICATION OF NOBECUTAN® AS BARRIER DRESSING].

    PubMed

    Esparza Imas, Gonzalo; Borruel Sola, María Pilar; González Gómez, Maria Teresa; Labarga Etulain, Cristna; Tarrío Fernández, Orencio; Lapeña Calavia, Sonia; Aguirre Gorospe, Sara; Muruzábal Torquemada, Juan Carlos

    2015-12-01

    The incidence of neoplasia of vulva round 1-2 per 100,000 women with predominance in ranges age of diagnosis between 65-75years. This type of cancer pathology is tackled with surgical techniques summarized in simple vulvectomy or vulvectomy with unilateral or bilateral lymphadenectomy according to staging of cutaneous involvement. The morbidity of this surgical process is mainly grouped in skin moisture, dehiscence and infection. The use of Nobecutan® as a plastic dressing aerosol barrier reduces cutaneous surgical comorbidity.

  7. Step-by-step surgical technique for mandibular reconstruction with fibular free flap: application of digital technology in virtual surgical planning.

    PubMed

    Succo, G; Berrone, M; Battiston, B; Tos, P; Goia, F; Appendino, P; Crosetti, E

    2015-06-01

    At present, mandibular reconstruction with a fibular free flap is the gold standard for functional and esthetic rehabilitation after oncological surgery. The purpose of this study was to describe the computer-assisted mandibular reconstruction procedure adopting the customized solution Synthes ProPlan CMF. The study reports five consecutive patients with benign or malignant disease requiring mandibular reconstruction using a microvascular fibular free flap, pre-operative virtual planning, construction of cutting guides and customized laser pre-bent titanium plates. The surgical technique is discussed in a step-by-step fashion. The average post-operative hospital stay was 18 ± 3 days. Ischemia time was recorded in all five cases, with an average of 75 ± 8 min. No problems were encountered in any surgical step and there were no major complications. Excellent precision of cutting guides and a good fit of pre-bent plates were found on both the mandible and fibula. There was excellent precision in bone to bone contact and position between mandible and fibula graft. Measurement data from the pre-operative and post-operative CT scans were compared. The average difference (Δ) between programed segment lengths and CT control segment lengths was 0.098 ± 0.077 cm. Microsurgical mandibular reconstruction using a virtual surgical planning yields significantly shorter ischemia times and allows more precise osteotomies. The technology is becoming increasingly recognized for its ability to optimize surgical outcomes and minimize operating time. Considering that the extent of resection can be wider than predicted, this results in safer modeling of the fibula only after frozen sections have demonstrated the radicality of resection.

  8. A modified surgical technique for reconstruction of an acute acromioclavicular joint dislocation

    PubMed Central

    Marchie, Anthony; Kumar, Arun; Catre, Melanio

    2009-01-01

    We report a modified surgical technique for reconstruction of coracoclavicular and acromioclavicular ligaments after acute dislocation of acromioclavicular joint using suture anchors. We have repaired 3 consecutive type III acromioclavicular dislocations with good results. This technique is simple and safe and allows anatomical reconstruction of the ligaments in acute dislocations. PMID:20671868

  9. Intraoperative neuromonitoring techniques in the surgical management of acoustic neuromas.

    PubMed

    Oh, Taemin; Nagasawa, Daniel T; Fong, Brendan M; Trang, Andy; Gopen, Quinton; Parsa, Andrew T; Yang, Isaac

    2012-09-01

    Unfavorable outcomes such as facial paralysis and deafness were once unfortunate probable complications following resection of acoustic neuromas. However, the implementation of intraoperative neuromonitoring during acoustic neuroma surgery has demonstrated placing more emphasis on quality of life and preserving neurological function. A modern review demonstrates a great degree of recent success in this regard. In facial nerve monitoring, the use of modern electromyography along with improvements in microneurosurgery has significantly improved preservation. Recent studies have evaluated the use of video monitoring as an adjunctive tool to further improve outcomes for patients undergoing surgery. Vestibulocochlear nerve monitoring has also been extensively studied, with the most popular techniques including brainstem auditory evoked potential monitoring, electrocochleography, and direct compound nerve action potential monitoring. Among them, direct recording remains the most promising and preferred monitoring method for functional acoustic preservation. However, when compared with postoperative facial nerve function, the hearing preservation is only maintained at a lower rate. Here, the authors analyze the major intraoperative neuromonitoring techniques available for acoustic neuroma resection. PMID:22937857

  10. [Optimization of approaches to the surgical treatment of patients with benign breast gland tumors].

    PubMed

    Usmanova, T É

    2014-06-01

    The results of 95 patients treatment with benign brest gland tumours (BBGT) were studied. For improve the results of treatment the introduction of surgical techniques that reduce the invasiveness of operations were applied. The performance of preoperative ultrasound (US) marking BB GT, cosmetically non-traumatic incisions, US dissector, combined cosmetic suture applay for the glandular tissue after sectoral resection of brest gland contribute to improving the results of surgical treatment, which is confirmed by the auspicious course of the early postoperative period.

  11. A novel surgical technique for transverse sternal bone defects using flexible intramedullary nailing.

    PubMed

    Böcker, W; Euler, E; Schieker, M; Kettler, M; Mutschler, W

    2006-12-01

    Transverse sternal bone defects as a result of surgery or trauma remain an important clinical condition with serious sequelae. Patients sometimes complain of local pain during movement and breathing. Usually, defects are filled with prosthetic materials which remain permanently IN SITU. Small defects can be treated with autogenous bone grafts, whereas large defects are difficult to stabilize with common osteosynthetic techniques. Here, we report a new surgical technique using flexible intramedullary nailing ("Elastic Stable Intramedullary Nailing"--ESIN or "Embrochage Centro-Medullaire Elastique Stable"--ECMES) to stabilize a sternal defect after surgical removal of an osteochondral lesion. The defect was bridged by two elastic titanium nails and an autogenous corticocancellous bone graft. This new surgical technique showed a good clinical and functional outcome. PMID:17151979

  12. Richter hernia: surgical anatomy and technique of repair.

    PubMed

    Skandalakis, Panagiotis N; Zoras, Odyseas; Skandalakis, John E; Mirilas, Petros

    2006-02-01

    Richter hernia (partial enterocele) is the protrusion and/or strangulation of only part of the circumference of the intestine's antimesenteric border through a rigid small defect of the abdominal wall. The first case was reported in 1606 by Fabricius Hildanus. The first definition of partial enterocele was given by August Gottlieb Richter in 1785. Sir Frederick Treves discriminated it from Littre hernia (hernia of the Meckel diverticulum). More often these hernias are diagnosed in the sixth and seventh decades of life. They comprise 10 per cent of strangulated hernias. Their common sites are the femoral ring, inguinal ring, and at incisional trauma. The most-often entrapped part of the bowel is the distal ileum, but any part of the intestinal tube may be incarcerated. These hernias progress more rapidly to gangrene than other strangulated hernias, and obstruction is less frequent. The gold standard technique for repair is the preperitoneal approach, followed by laparotomy and resection if perforation is suspected.

  13. Evaluation of the effect of pulmonary hydatid cyst location on the surgical technique approaches

    PubMed Central

    Sadrizadeh, Ali; Haghi, Seyed Ziaollah; Masuom, Seyed Hossein Fattahi; Bagheri, Reza; Dalouee, Marziyeh Nouri

    2014-01-01

    Purpose: A hydatid cyst is the most common lung parasitic disease and is endemic in Iran. A hydatid cyst is more common in the right lung and lower lobes. Objective: The aim of this study was to assess surgical treatment of pulmonary hydatid cysts and whether the location of cyst affects surgical technique approaches. Materials and Methods: This study was performed on 87 patients with a pulmonary hydatid cyst who were referred to Qaem Hospital from 2010 to 2012. Selection of surgical technique was according to size, location, and the number of cysts. Patients were divided into two groups: (1) surgery with preserving lung parenchyma and (2) lobectomy. Afterward, the relationship between the location of cyst and surgical technique approaches was evaluated. Data was analyzed by Chi-square and Fisher exact tests. Results: In this study, no significant relation was found between the size (P = 0.682) and number (P = 0.344) of cysts and lobectomy necessity. But, there was a significant relation between the occurrence of cyst in middle lobe and lobectomy necessity (P = 0.016). Conclusions: According to the results, type of surgical technique does not depend on the size and number of cysts, but it may be related to the location of the cyst and the ratio of lung destruction. PMID:25378844

  14. Bursectomy in gastric cancer surgery: surgical technique and operative safety.

    PubMed

    Blouhos, Konstantinos; Boulas, Konstantinos A; Hatzigeorgiadis, Anestis

    2013-06-01

    Although there is little evidence that bursectomy has clinical benefit, its continuing practice imposes evaluation of bursectomy-related adverse effects, especially pancreatic fistula and intestinal obstruction. The aims of this study were to provide a detailed description of the technique of bursectomy as standardized by the authors and determine if extended surgery for gastric cancer with additional bursectomy can be performed safely in Western population. A total of 72 consecutive patients of median age 76.4 years and mean ASA score grade 2.1, who submitted to D2 or D2+ gastrectomy with additional bursectomy for gastric adenocarcinoma, were prospectively studied. Bursectomy was associated with a median additional operative time of 41 min and a median additional blood loss of 65 ml. The post-operative morbidity rate was 19.4 %. Among various adverse events, pancreatic fistula was observed in three patients (4.2 %) and intestinal obstruction was observed in eight patients (11.1 %) including two cases of delayed gastric emptying, one case of afferent loop syndrome, one case of early postoperative adhesions and four cases of prolonged postoperative ileus. The in-hospital mortality rate was 1.4 %. D2 or D2+ gastrectomy with additional bursectomy can be safely performed in Western patients. Although the incidence of pancreatic fistula that we reported was low, the incidence of bursectomy-related intestinal obstruction was high and should always be kept in mind when performing extended surgery for gastric cancer. PMID:23592040

  15. [Surgical techniques for thoracic and thoracoabdominal aneurysm repair].

    PubMed

    Imoto, K; Uchida, K

    2010-07-01

    We introduce our technique for the treatment of aneurysms arising in the descending thoracic aorta and the thoracoabdominal aorta. Thoracotomy is performed at a single site. The costal arch is transected to ensure an adequate field of vision. A lifting hook is used to open the proximal side of the aorta. The diaphragm is not totally transected to preserve respiratory function after surgery. In principle, partial extracorporeal circulation is performed using a percutaneous cardiopulmonary support system. The dose of heparin for systemic treatment is limited to 50 U/kg. The abdominal branches are perfused with the use of balloon catheters. Cardiac arrest is induced for about 10 seconds by intravenous administration of adenosine triphosphate to avoid aortic injury when the proximal aorta is clamped during partial extracorporeal circulation and to prevent massive bleeding when the elephant trunk is clamped. To prevent paraplegia, the Adamkiewics artery and 2 pairs of adjacent intercostal arteries identified by preoperative computed tomography are reconstructed, and cerebrospinal drainage and motor evoked potential monitoring are performed.

  16. Imaging techniques for infections in the surgical patient

    SciTech Connect

    Gerzof, S.G.; Oates, M.E.

    1988-02-01

    Gallium-67 citrate is easy to use and readily available, but the need to delay imaging for 2 to 4 days after injection hinders rapid diagnosis. Moreover, normal gastrointestinal activity limits its usefulness in evaluating the abdomen. Labeling leukocytes with Indium-111 oxine is a time-consuming, technically involved process, yet the images obtained at 24 hours will usually reveal sites of inflammation or infection. Although the techniques have similar sensitivities, the higher specificity of In-111 makes it the superior agent for many clinical situations. When there are localizing signs or symptoms or a reason to suspect a specific body region, CT or ultrasonography is the imaging modality of choice. Guided needle aspiration can then be performed and is usually diagnostic. Radionuclide imaging with either Ga-67 or In-111 is available as an adjunct if needle aspiration cannot be performed or is inconclusive. Since it provides total-body surveillance, radionuclide imaging is particularly useful for screening when there are no localizing signs and in cases of occult sepsis or fever of unknown origin. If positive, it can direct further imaging with CT or ultrasound. 46 references.

  17. A Practical Surgical Technique to Expose the Mental Nerve in Narrowing Genioplasty.

    PubMed

    Wang, Chenglong; Gui, Lai; Liu, Jianfeng

    2015-11-01

    In this article, the authors present a practical surgical technique using the anatomical character of the inferior alveolar nerve to fully expose the mental nerve (MN) in narrowing genioplasty. During the procedure, a rectangular mandibular outer cortex adjacent to the mental foramen is removed before the osteotomy. The objective is to avoid the injury of the MN from the reciprocating saw or bur and offer abundant space for the surgical operation. The technique has a minimal learning curve and will be useful to plastic surgeons to minimize unintentional cutting or pulling injury to the MN in narrowing genioplasty. PMID:26893979

  18. Minimally invasive corticotomy in orthodontics: a new technique using a CAD/CAM surgical template.

    PubMed

    Cassetta, M; Pandolfi, S; Giansanti, M

    2015-07-01

    Accelerating orthodontic tooth movement is a topical issue. Despite the different techniques described in the literature, the corticotomy is the only effective and safe means of accelerating orthodontic tooth movement. Although effective, the corticotomy presents significant postoperative discomfort. The aggressive nature of these particular methods, related to the elevation of mucoperiosteal flaps and to the length of the surgery, has resulted in reluctance to proceed with this technique among both patients and the dental community. To overcome the disadvantages of the corticotomy, this technical note describes an innovative, minimally invasive, flapless procedure combining piezoelectric surgical cortical micro-incisions with the use of a 3D Printed CAD/CAM surgical guide.

  19. Brain abscess and subdural empyema. Factors influencing mortality and results of various surgical techniques.

    PubMed Central

    Van Alphen, H A; Dreissen, J J

    1976-01-01

    The authors review the results of various surgical techniques in relation to mortality and morbidity in 100 consecutive cases of brain abscess and subdural empyema. The mortality rate is the same with total excision and fractional drainage of brain abscesses, although in acute and subacute cases slight differences between both techniques are seen. In terms of morbidity, fractional drainage appears to be more favourable than total excision. The authors believe that factors other than surgical procedure influence mortality in cases of brain abscess and subdural empyema. These factors are defined in detail. Images PMID:932767

  20. Surgical Technique: Endoscopic Endonasal Transphenoidal Resection of a Large Suprasellar Mixed Germ Cell Tumor

    PubMed Central

    Chakravarthy, Vikram; Hanna, George; DeLos Reyes, Kennethy

    2016-01-01

    The endoscopic endonasal transphenoidal approach has proven to be a very versatile surgical approach for the resection of small midline skull base tumors. This is due to its minimally invasive nature, the potentially fewer neurological complications, and lower morbidity in comparison to traditional craniotomies. This surgical approach has been less commonly utilized for large midline tumors such as suprasellar germ cell tumors, due to numerous reasons including the surgeon’s comfort with the surgical approach, a higher chance of postoperative cerebrospinal fluid (CSF) leak, limited visualization due to arterial/venous bleeding, and limited working space. We present our surgical technique in the case of a large suprasellar and third ventricular mixed germ cell tumor that was resected via an endoscopic endonasal approach with favorable neurological outcome and no postoperative CSF leak. PMID:27014537

  1. Individualized optimal surgical extent of the lateral neck in papillary thyroid cancer with lateral cervical metastasis.

    PubMed

    Park, Jae-Yong; Koo, Bon Seok

    2014-06-01

    Despite an excellent prognosis, cervical lymph node (LN) metastases are common in patients with papillary thyroid cancer (PTC). The presence of metastasis is associated with an increased risk of locoregional recurrence, which significantly impairs quality of life and may decrease survival. Therefore, it has been an important determinant of the extent of lateral LN dissection in the initial treatment of PTC patients with lateral cervical metastasis. However, the optimal extent of therapeutic lateral neck dissection (ND) remains controversial. Optimizing the surgical extent of LN dissection is fundamental for balancing the surgical morbidity and oncological benefits of ND in PTC patients with lateral neck metastasis. We reviewed the currently available literature regarding the optimal extent of lateral LN dissection in PTC patients with lateral neck metastasis. Even in cases with suspicion of metastatic LN at the single lateral level or isolated metastatic lateral LN, the application of ND including all sublevels from IIa and IIb to Va and Vb may be overtreatment, due to the surgical morbidity. When there is no suspicion of LN metastasis at levels II and V, or when multilevel aggressive neck metastasis is not found, sublevel IIb and Va dissection may not be necessary in PTC patients with lateral neck metastasis. Thus consideration of the individualized optimal surgical extent of lateral ND is important when treating PTC patients with lateral cervical metastasis.

  2. Comparison of Surgical Techniques for Ulnar Collateral Ligament Reconstruction in Overhead Athletes.

    PubMed

    Chang, Edward S; Dodson, Christopher C; Ciccotti, Michael G

    2016-03-01

    Several surgical techniques and modifications for ulnar collateral ligament (UCL) reconstruction have been proposed since this procedure was first performed in 1974. The goal of these techniques has been restoration of stability to the medial elbow with minimal alteration to the surrounding anatomy. Outcome studies and systematic reviews on modified techniques for UCL reconstruction have shown a trend toward increased return to play in patients, particularly overhead athletes. Abandonment of flexor pronator mass detachment in favor of a muscle-splitting or muscle-elevating approach, minimal handling of the ulnar nerve, and the docking technique may result in improved outcomes and decreased complications without diminished performance. Several biomechanical studies have compared the structural properties of these techniques with those of the native UCL. However, a clear, concise surgical algorithm for UCL reconstruction is lacking. Additional studies that use sport-specific outcome measures and performance metrics may better demonstrate the true return to preinjury performance after UCL reconstruction in overhead athletes.

  3. Optimizing correlation techniques for improved earthquake location

    USGS Publications Warehouse

    Schaff, D.P.; Bokelmann, G.H.R.; Ellsworth, W.L.; Zanzerkia, E.; Waldhauser, F.; Beroza, G.C.

    2004-01-01

    Earthquake location using relative arrival time measurements can lead to dramatically reduced location errors and a view of fault-zone processes with unprecedented detail. There are two principal reasons why this approach reduces location errors. The first is that the use of differenced arrival times to solve for the vector separation of earthquakes removes from the earthquake location problem much of the error due to unmodeled velocity structure. The second reason, on which we focus in this article, is that waveform cross correlation can substantially reduce measurement error. While cross correlation has long been used to determine relative arrival times with subsample precision, we extend correlation measurements to less similar waveforms, and we introduce a general quantitative means to assess when correlation data provide an improvement over catalog phase picks. We apply the technique to local earthquake data from the Calaveras Fault in northern California. Tests for an example streak of 243 earthquakes demonstrate that relative arrival times with normalized cross correlation coefficients as low as ???70%, interevent separation distances as large as to 2 km, and magnitudes up to 3.5 as recorded on the Northern California Seismic Network are more precise than relative arrival times determined from catalog phase data. Also discussed are improvements made to the correlation technique itself. We find that for large time offsets, our implementation of time-domain cross correlation is often more robust and that it recovers more observations than the cross spectral approach. Longer time windows give better results than shorter ones. Finally, we explain how thresholds and empirical weighting functions may be derived to optimize the location procedure for any given region of interest, taking advantage of the respective strengths of diverse correlation and catalog phase data on different length scales.

  4. Endoscopic Debridement for Treatment of Chronic Plantar Fasciitis: An Innovative Surgical Technique.

    PubMed

    Cottom, James M; Maker, Jared M

    2016-01-01

    Plantar fasciitis is one the most common pathologies seen by foot and ankle surgeons. When nonoperative therapy fails, surgical intervention is warranted. Various surgical procedures are available for the treatment of recalcitrant plantar fasciitis. The most common surgical management typically consists of open versus endoscopic plantar fascia release. The documented comorbidities associated with the release of the plantar fascia include lateral column overload and metatarsalgia. We present a new technique for this painful condition that is minimally invasive, allows visualization of the plantar fascia, and maintains the integrity of this fascia. Our hypothesis was that the use of endoscopic debridement of the plantar fascia would provide a minimally invasive technique with acceptable patient outcomes.

  5. Endoscopic Debridement for Treatment of Chronic Plantar Fasciitis: An Innovative Surgical Technique.

    PubMed

    Cottom, James M; Maker, Jared M

    2016-01-01

    Plantar fasciitis is one the most common pathologies seen by foot and ankle surgeons. When nonoperative therapy fails, surgical intervention is warranted. Various surgical procedures are available for the treatment of recalcitrant plantar fasciitis. The most common surgical management typically consists of open versus endoscopic plantar fascia release. The documented comorbidities associated with the release of the plantar fascia include lateral column overload and metatarsalgia. We present a new technique for this painful condition that is minimally invasive, allows visualization of the plantar fascia, and maintains the integrity of this fascia. Our hypothesis was that the use of endoscopic debridement of the plantar fascia would provide a minimally invasive technique with acceptable patient outcomes. PMID:26952313

  6. Successful surgical repair of a triple cardiac rupture using modified cohesive double patch technique.

    PubMed

    Dorobantu, Lucian Florin; Stiru, Ovidiu; Iliescu, Vlad Anton

    2016-02-01

    Introduction The association between both left and right ventricular free wall ruptures (FWR) and post-infarction anterior ventricular septal defect (VSD) is an exceptional situation. Case report We present the case of a patient who developed a VSD and two FWRs (of the left and right ventricle, respectively) shortly after the onset of an anterior AMI. We surgically closed this complex rupture using the cohesive double patch technique with two Teflon patches combined with an infarct exclusion technique. The left and right ventricular patches were attached cohesively to the septal wall and the infarcted area was excluded without reducing the left ventricular cavity. Conclusion Association between post-infarction ventricular septal rupture and both left and right free wall ruptures are a very rare and dangerous situation. The modified cohesive double patch technique associated the modified Cooley technique seems to be the correct surgical solution. PMID:27385145

  7. Comparative study of 2 surgical techniques for castration of guinea pigs (Cavia porcellus)

    PubMed Central

    Guilmette, Josée; Langlois, Isabelle; Hélie, Pierre; de Oliveira El Warrak, Alexander

    2015-01-01

    The objective of this study was to compare 2 surgical approaches (scrotal or abdominal) for castration of guinea pigs and to investigate post-operative infection rates with either technique. Forty-eight guinea pigs were castrated by scrotal or abdominal technique after being randomly assigned to 1 of 2 groups (n = 24). Individuals were either castrated by an experienced exotic animal surgeon (n = 12) or by an experienced small animal surgeon (n = 12). Surgical wounds were evaluated daily before euthanasia for histological evaluation 2 wks after surgery. Post-operative infection rate was significantly higher in the scrotal group than in the abdominal group, with a higher rate for the experienced small animal surgeon. Castration of guinea pigs with the abdominal technique is significantly faster and has a significantly lower post-operative infection rate than the scrotal technique. PMID:26424914

  8. Promoting teamwork and surgical optimization: combining TeamSTEPPS with a specialty team protocol.

    PubMed

    Tibbs, Sheila Marie; Moss, Jacqueline

    2014-11-01

    This quality improvement project was a 300-day descriptive preintervention and postintervention comparison consisting of a convenience sample of 18 gynecology surgical team members. We administered the Team Strategies & Tools to Enhance Performance and Patient Safety (TeamSTEPPS®) Teamwork Perception Questionnaire to measure the perception of teamwork. In addition, we collected data regarding rates of compliance (ie, huddle, time out) and measurable surgical procedure times. Results showed a statistically significant increase in the number of team members present for each procedure, 2.34 μ before compared with 2.61 μ after (P = .038), and in the final time-out (FTO) compliance as a result of a clarification of the definition of FTO, 1.05 μ before compared with 1.18 μ after (P = .004). Additionally, there was improvement in staff members' perception of teamwork. The implementation of team training, protocols, and algorithms can enhance surgical optimization, communication, and work relationships.

  9. Vaginal-sparing ventral buccal mucosal graft urethroplasty for female urethral stricture: A novel modification of surgical technique

    PubMed Central

    Gani, Johan; Chee, Justin

    2016-01-01

    Purpose To present a novel modification of surgical technique to treat female urethral stricture (FUS) by a vaginal-sparing ventral buccal mucosal urethroplasty. Recurrent FUS represents an uncommon, though difficult clinical scenario to manage definitively. A variety of surgical techniques have been described to date, yet a lack of consensus on the optimal procedure persists. Materials and Methods We present a 51-year-old female with urethral stricture involving the entire urethra. Suspected etiology was iatrogenic from cystoscopy 17 years prior. Since then, the patient had undergone at least 25 formal urethral dilations and periods of self-dilation. In lithotomy position, the urethra was dilated to accommodate forceps, and ventral urethrotomy carried out sharply, exposing a bed of periurethral tissue. Buccal mucosa was harvested, and a ventral inlay technique facilitated by a nasal speculum, was used to place the graft from the proximal urethra/bladder neck to urethral meatus without a vaginal incision. Graft was sutured into place, and urethral Foley catheter inserted. Results The vaginal-sparing ventral buccal mucosal graft urethroplasty was deemed successful as of last follow-up. Flexible cystoscopy demonstrated patency of the repair at 6 months. At 10 months of follow-up, the patient was voiding well, with no urinary incontinence. No further interventions have been required. Conclusions This case describes a novel modification of surgical technique for performing buccal mucosal urethroplasty for FUS. By avoiding incision of the vaginal mucosa, benefits may include reduced: morbidity, urinary incontinence, and wound complications including urethro-vaginal fistula. PMID:27437540

  10. Measurement of blood flow through surgical anastomosis using the radioactive microsphere technique

    SciTech Connect

    Hummel, S.J.; Delgado, G.; Butterfield, A.; Dritschilo, A.; Harbert, J.

    1985-10-01

    Two different radioactive microspheres ( U Ce and UWSc) were used to measure blood flow to an area of the large intestine in dogs before and after a surgical resection was performed with surgical staples. The healing of an anastomosis is theoretically related to the blood flow to the anastomotic site. Blood flow studies were conducted in three dogs using this technique. The average blood flow preoperatively was 0.558 mL/minute per gram and 1.04 mL/minute per gram postoperatively. These results indicate a statistically significant increase in blood flow at the anastomotic site six days after anastomosis when compared with the blood flow to the same area before any surgical procedures.

  11. Unstable elbow dislocations: a case report of a new surgical technique

    PubMed Central

    Harris, Mark; McMahon, Sarah; Bishop, Timothy; Bernard, Jason

    2016-01-01

    This case report describes our first clinical experience of a previously described new surgical technique for the treatment of unstable simple elbow dislocations. The technique utilises a central strip of the distal triceps tendon which is harvested proximally at the musculotendonous junction and left attached at its insertion on the olecranon. The strip is the passed through the olecranon fossa and attached to the coronoid process to stabilise the joint. We encountered an early postoperative complication that led to a modification of our technique and ultimately an excellent recovery of a stable pain free joint with a full range of movement. PMID:27163104

  12. Management of posttraumatic kyphosis: surgical technique to facilitate a combined approach.

    PubMed

    Marré, Bartolomé

    2005-07-01

    This report describes a variation of the "posterior-anterior-posterior" surgical techniques to correct posttraumatic kyphosis of the thoracic and lumbar spine with the USS internal fixator. This modification is based on the use of "temporary screws" to mark the entrance of the pedicles in the first stage of the operation (posterior approach, with the patient in prone position). Approaching both columns of the spine simultaneously facilitates correction of the kyphotic defect and permits 360 reconstruction of the spine. PMID:15993120

  13. A mesh gradient technique for numerical optimization

    NASA Technical Reports Server (NTRS)

    Willis, E. A., Jr.

    1973-01-01

    A class of successive-improvement optimization methods in which directions of descent are defined in the state space along each trial trajectory are considered. The given problem is first decomposed into two discrete levels by imposing mesh points. Level 1 consists of running optimal subarcs between each successive pair of mesh points. For normal systems, these optimal two-point boundary value problems can be solved by following a routine prescription if the mesh spacing is sufficiently close. A spacing criterion is given. Under appropriate conditions, the criterion value depends only on the coordinates of the mesh points, and its gradient with respect to those coordinates may be defined by interpreting the adjoint variables as partial derivatives of the criterion value function. In level 2, the gradient data is used to generate improvement steps or search directions in the state space which satisfy the boundary values and constraints of the given problem.

  14. A surgical glove port technique for laparoscopic-assisted ovariohysterectomy for pyometra in the bitch.

    PubMed

    Becher-Deichsel, Anja; Aurich, Jörg E; Schrammel, Nadine; Dupré, Gilles

    2016-07-15

    The objective of the study was to describe the feasibility of a glove port technique for laparoscopic-assisted surgical treatment of canine pyometra. In this retrospective case series, a total of 10 female dogs (median age 7 years, range 5.5-10.5 years; median weight 37.0 kg, range 12.9-64.0 kg) with pyometra were included. A multiaccess port was created from a surgical glove attached to an Alexis wound retractor and placed in the ventral midline between the middle and caudal third of the distance between umbilicus and pubic rim. A vessel sealing device was used for transection of the ovarian pedicle. The port size was selected on the basis of maximum uterine diameter determined by ultrasound. Median incision length was 5.0 cm (range 3.1-7.7 cm) for a maximum uterine diameter of 4.0 cm (range 2.0-7.0 cm). Median surgical time was 57 minutes (range 48-65 minutes). No case had to be converted to open celiotomy. Complications included one case of minor, self-limiting splenic trauma by the endoscope. In eight dogs, the distended uterine horns endangered safe access to the ovarian pedicle, and the vessel sealing device was inserted through a second cannula placed periumbilically. Extension of the original incision was necessary to exteriorize organs in two dogs. All dogs recovered quickly and were discharged either on the day of surgery or 1 day thereafter. In conclusion, a surgical glove port technique in combination with an Alexis wound retractor is feasible for surgical laparoscopic treatment of canine pyometra up to a diameter of 7 cm. PMID:27039076

  15. Surgical extrusion technique for clinical crown lengthening: report of three cases.

    PubMed

    Kim, Chang-Sung; Choi, Seong-Ho; Chai, Jung-Kiu; Kim, Chong-Kwan; Cho, Kyoo-Sung

    2004-10-01

    Although a number of techniques have been proposed for clinical crown lengthening procedures, all have some limitation in terms of function and esthetics. This report presents the clinical and radiographic results of a surgical extrusion technique for clinical crown lengthening. Atraumatic surgical extrusion using a specially designed instrument (Periotome) was performed in three cases in which it was expected that extensive resective osseous surgery would have to be used for crown lengthening. Full-thickness mucoperiosteal flaps were raised both labially and palatally. The tooth was carefully luxated and extruded to the desired position without damaging the marginal bone area or root apex. No rigid splint was applied. Clinical examinations performed for more than 1 year after surgery revealed probing depths < or = 3 mm around the teeth at all sites, without bleeding on probing. The teeth functioned normally, with near-normal mobility. Radiographs showed normal periodontal contour consistent with new bone formation in the periapical area. Radiographic analysis did not show any evidence of root or crestal bone resorption or endodontic problems. The technique presented could constitute an alternative surgical approach to performing crown lengthening; it does not induce functional or esthetic deformities, especially in the anterior region.

  16. Optimization Techniques for College Financial Aid Managers

    ERIC Educational Resources Information Center

    Bosshardt, Donald I.; Lichtenstein, Larry; Palumbo, George; Zaporowski, Mark P.

    2010-01-01

    In the context of a theoretical model of expected profit maximization, this paper shows how historic institutional data can be used to assist enrollment managers in determining the level of financial aid for students with varying demographic and quality characteristics. Optimal tuition pricing in conjunction with empirical estimation of…

  17. Surgical treatment of combined PCL-ACL medial and lateral side injuries (global laxity): surgical technique and 2- to 18-year results.

    PubMed

    Fanelli, Gregory C; Edson, Craig J

    2012-09-01

    The multiple ligament injured knee is a severe injury that may also involve neurovascular injuries, fractures, and other systemic injuries. Surgical treatment offers good functional results documented in the literature by physical examination, arthrometer testing, stress radiography, and knee ligament rating scales. Mechanical tensioning devices are helpful with cruciate ligament tensioning. Some low grade medial collateral ligament (MCL) complex injuries may be amenable to brace treatment, while high grade medial side injuries require combined surgical repair-reconstruction. Lateral posterolateral injuries are most successfully treated with combined surgical repair-reconstruction. Surgical timing in acute multiple ligament injured knee cases depends on the ligaments injured, injured extremity vascular status, skin condition of the extremity, degree of instability, and the patients overall health. Allograft tissue is preferred for these complex surgical procedures. Delayed reconstruction of 2 to 3 weeks may decrease the incidence of arthrofibrosis, and it is important to address all components of the instability. Currently, there is no conclusive evidence that double-bundle posterior cruciate ligament (PCL) reconstruction provides superior results to single-bundle PCL reconstruction in the multiple ligament injured knee. The purpose of this article is to discuss G.F.'s surgical technique for combined PCL and anterior cruciate ligament, medial, and lateral side reconstructions in acute and chronic multiple ligament injured knees with global laxity. This article will focus on recognizing and defining the instability pattern, the use of external fixation, surgical timing, graft selection and preparation, G.F.'s preferred surgical technique, mechanical graft tensioning, perioperative antibiotics, specialized operating teams, postoperative rehabilitation, and our results of treatment in these complex surgical cases.

  18. Unique Technique for Open Surgical Repair after Failed Endovascular Aneurysm Repair with Proximal Anastomoses.

    PubMed

    Takebayashi, Satoshi; Hirota, Jun; Mori, Kazuki; Shuto, Takashi; Okamoto, Keitaro; Sato, Aiko; Wada, Tomoyuki; Anai, Hirofumi; Miyamoto, Shinji

    2016-01-01

    Endovascular aortic aneurysm repair (EVAR) has revolutionized the management of abdominal aortic aneurysms (AAAs), with lower perioperative morbidity and mortality compared to conventional surgical repair. However, late secondary re-interventions after EVAR are still needed before aneurysm rupture in many cases. A patient with impending rupture of an AAA associated with a type I endoleak 7 years after EVAR who was successfully treated with a unique technique of fixation of the proximal aortic neck taking into account the structure of the stent graft is reported. This technique offers a safe solution to late open conversion after failed EVAR. PMID:27375808

  19. Unique Technique for Open Surgical Repair after Failed Endovascular Aneurysm Repair with Proximal Anastomoses

    PubMed Central

    Hirota, Jun; Mori, Kazuki; Shuto, Takashi; Okamoto, Keitaro; Sato, Aiko; Wada, Tomoyuki; Anai, Hirofumi; Miyamoto, Shinji

    2016-01-01

    Endovascular aortic aneurysm repair (EVAR) has revolutionized the management of abdominal aortic aneurysms (AAAs), with lower perioperative morbidity and mortality compared to conventional surgical repair. However, late secondary re-interventions after EVAR are still needed before aneurysm rupture in many cases. A patient with impending rupture of an AAA associated with a type I endoleak 7 years after EVAR who was successfully treated with a unique technique of fixation of the proximal aortic neck taking into account the structure of the stent graft is reported. This technique offers a safe solution to late open conversion after failed EVAR. PMID:27375808

  20. Hepatic MR imaging techniques, optimization, and artifacts.

    PubMed

    Guglielmo, Flavius F; Mitchell, Donald G; Roth, Christopher G; Deshmukh, Sandeep

    2014-08-01

    This article describes a basic 1.5-T hepatic magnetic resonance (MR) imaging protocol, strategies for optimizing pulse sequences while managing artifacts, the proper timing of postgadolinium 3-dimensional gradient echo sequences, and an effective order of performing pulse sequences with the goal of creating an efficient and high-quality hepatic MR imaging examination. The authors have implemented this general approach on General Electric, Philips, and Siemens clinical scanners.

  1. Neural network training with global optimization techniques.

    PubMed

    Yamazaki, Akio; Ludermir, Teresa B

    2003-04-01

    This paper presents an approach of using Simulated Annealing and Tabu Search for the simultaneous optimization of neural network architectures and weights. The problem considered is the odor recognition in an artificial nose. Both methods have produced networks with high classification performance and low complexity. Generalization has been improved by using the backpropagation algorithm for fine tuning. The combination of simple and traditional search methods has shown to be very suitable for generating compact and efficient networks.

  2. Axillary dissection in primary breast cancer: variations of the surgical technique and influence on morbidity.

    PubMed

    Wojcinski, Sebastian; Nuengsri, Sirin; Hillemanns, Peter; Schmidt, Werner; Deryal, Mustafa; Ertan, Kubilay; Degenhardt, Friedrich

    2012-01-01

    Lymphedema of the arm is the most common and impairing complication after breast cancer surgery with axillary lymph node dissection (ALND). Our prospective study evaluated the effect of two different surgical techniques for ALND on postoperative morbidity. Patients were scheduled to undergo ALND. Patients in group 1 (n = 17) underwent the most common and standard technique of ALND, which uses sharp dissection of the tissue and subsequent electro-coagulation of bleedings. Patients in group 2 (n = 17) underwent a modified standard technique of ALND with clamping and ligatures of all resection margins. Postoperative wound secretion was quantified and patients were followed up for 6 months to assess long-term morbidity. The variations in surgical technique had no significant influence on the outcome variables. However, patients in group 2 showed a tendency to less wound secretion (713 versus 802 mL; P = nonsignificant), a decreased rate of immediate postoperative seromas (11.8 versus 23.5%; P = nonsignificant) and less lymphedema after 3 months (29.4 versus 41.2%; P = nonsignificant). Moreover, the number of resected lymph nodes correlated with the total amount of drained fluid (P = 0.006), the duration of the drain (P = 0.015), and the risk for the development of lymphedema after 3 months (P = 0.016). The described variations in surgical technique had no influence on the outcomes of the patients. The number of resected axillary lymph nodes remains the most important risk factor for treatment-related morbidity. Therefore, a well-balanced choice of the extent of the axillary dissection should be the surgeon's main concern. PMID:22570566

  3. Axillary dissection in primary breast cancer: variations of the surgical technique and influence on morbidity

    PubMed Central

    Wojcinski, Sebastian; Nuengsri, Sirin; Hillemanns, Peter; Schmidt, Werner; Deryal, Mustafa; Ertan, Kubilay; Degenhardt, Friedrich

    2012-01-01

    Lymphedema of the arm is the most common and impairing complication after breast cancer surgery with axillary lymph node dissection (ALND). Our prospective study evaluated the effect of two different surgical techniques for ALND on postoperative morbidity. Patients were scheduled to undergo ALND. Patients in group 1 (n = 17) underwent the most common and standard technique of ALND, which uses sharp dissection of the tissue and subsequent electro-coagulation of bleedings. Patients in group 2 (n = 17) underwent a modified standard technique of ALND with clamping and ligatures of all resection margins. Postoperative wound secretion was quantified and patients were followed up for 6 months to assess long-term morbidity. The variations in surgical technique had no significant influence on the outcome variables. However, patients in group 2 showed a tendency to less wound secretion (713 versus 802 mL; P = nonsignificant), a decreased rate of immediate postoperative seromas (11.8 versus 23.5%; P = nonsignificant) and less lymphedema after 3 months (29.4 versus 41.2%; P = nonsignificant). Moreover, the number of resected lymph nodes correlated with the total amount of drained fluid (P = 0.006), the duration of the drain (P = 0.015), and the risk for the development of lymphedema after 3 months (P = 0.016). The described variations in surgical technique had no influence on the outcomes of the patients. The number of resected axillary lymph nodes remains the most important risk factor for treatment-related morbidity. Therefore, a well-balanced choice of the extent of the axillary dissection should be the surgeon’s main concern. PMID:22570566

  4. Axillary dissection in primary breast cancer: variations of the surgical technique and influence on morbidity.

    PubMed

    Wojcinski, Sebastian; Nuengsri, Sirin; Hillemanns, Peter; Schmidt, Werner; Deryal, Mustafa; Ertan, Kubilay; Degenhardt, Friedrich

    2012-01-01

    Lymphedema of the arm is the most common and impairing complication after breast cancer surgery with axillary lymph node dissection (ALND). Our prospective study evaluated the effect of two different surgical techniques for ALND on postoperative morbidity. Patients were scheduled to undergo ALND. Patients in group 1 (n = 17) underwent the most common and standard technique of ALND, which uses sharp dissection of the tissue and subsequent electro-coagulation of bleedings. Patients in group 2 (n = 17) underwent a modified standard technique of ALND with clamping and ligatures of all resection margins. Postoperative wound secretion was quantified and patients were followed up for 6 months to assess long-term morbidity. The variations in surgical technique had no significant influence on the outcome variables. However, patients in group 2 showed a tendency to less wound secretion (713 versus 802 mL; P = nonsignificant), a decreased rate of immediate postoperative seromas (11.8 versus 23.5%; P = nonsignificant) and less lymphedema after 3 months (29.4 versus 41.2%; P = nonsignificant). Moreover, the number of resected lymph nodes correlated with the total amount of drained fluid (P = 0.006), the duration of the drain (P = 0.015), and the risk for the development of lymphedema after 3 months (P = 0.016). The described variations in surgical technique had no influence on the outcomes of the patients. The number of resected axillary lymph nodes remains the most important risk factor for treatment-related morbidity. Therefore, a well-balanced choice of the extent of the axillary dissection should be the surgeon's main concern.

  5. A new technique for feeding dogs with a congenital cleft palate for surgical research.

    PubMed

    Martínez-Sanz, Elena; Casado-Gómez, Inmaculada; Martín, Concepción; López-Gordillo, Yamila; González, Pablo; Rodríguez-Bobada, Cruz; Paradas, Irene; González-Meli, Beatriz; Maldonado, Estela; Maestro, Carmen; Prados, Juan Carlos; Martínez-Álvarez, Concepción

    2011-04-01

    In humans, cleft palate (CP) is one of the most common malformations. Although surgeons use palatoplasty to close CP defects in children, its consequences for subsequent facial growth have prompted investigations into other novel surgical alternatives. The animal models of CP used to evaluate new surgical treatments are frequently obtained by creating surgically induced clefts in adult dogs. This procedure has been ethically criticized due to its severity and questionable value as an animal model for human CP. Dogs born with a congenital CP would be much better for this purpose, provided they developed CP at a sufficient rate and could be fed. Up until now, feeding these pups carried the risk of aspiration pneumonia, while impeding normal suckling and chewing, and thus compromising orofacial growth. We developed a technique for feeding dog pups with CP from birth to the time of surgery using two old Spanish pointer dog pups bearing a complete CP. This dog strain develops CP in 15-20% of the offspring spontaneously. Custom-made feeding teats and palatal prostheses adapted to the pups' palates were made from thermoplastic plates. This feeding technique allowed lactation, eating and drinking in the pups with CP, with only sporadic rhinitis. To determine whether the use of this palatal prosthesis interferes with palatal growth, the palates of three littermate German shorthaired pointer pups without CP, either wearing or not wearing (controls) the prosthesis, were measured. The results showed that the permanent use of this prosthesis does not impede palatal growth in the pups.

  6. Surgical techniques for the treatment of ankyloglossia in children: a case series.

    PubMed

    Junqueira, Marina Azevedo; Cunha, Nayara Nery Oliveira; Costa e Silva, Lidiane Lucas; Araújo, Leandro Borges; Moretti, Ana Beatriz Silveira; Couto Filho, Carlos Eduardo Gomes; Sakai, Vivien Thiemy

    2014-06-01

    This paper reports a series of clinical cases of ankyloglossia in children, which were approached by different techniques: frenotomy and frenectomy with the use of one hemostat, two hemostats, a groove director or laser. Information on the indications, contraindications, advantages and disadvantages of the techniques was also presented. Children diagnosed with ankyloglossia were subjected to different surgical procedures. The choice of the techniques was based on the age of the patient, length of the frenulum and availability of the instruments and equipment. All the techniques presented are successful for the treatment of ankyloglossia and require a skilled professional. Laser may be considered a simple and safe alternative for children while reducing the amount of local anesthetics needed, the bleeding and the chances of infection, swelling and discomfort. PMID:25025566

  7. Surgical techniques for the treatment of ankyloglossia in children: a case series.

    PubMed

    Junqueira, Marina Azevedo; Cunha, Nayara Nery Oliveira; Costa e Silva, Lidiane Lucas; Araújo, Leandro Borges; Moretti, Ana Beatriz Silveira; Couto Filho, Carlos Eduardo Gomes; Sakai, Vivien Thiemy

    2014-06-01

    This paper reports a series of clinical cases of ankyloglossia in children, which were approached by different techniques: frenotomy and frenectomy with the use of one hemostat, two hemostats, a groove director or laser. Information on the indications, contraindications, advantages and disadvantages of the techniques was also presented. Children diagnosed with ankyloglossia were subjected to different surgical procedures. The choice of the techniques was based on the age of the patient, length of the frenulum and availability of the instruments and equipment. All the techniques presented are successful for the treatment of ankyloglossia and require a skilled professional. Laser may be considered a simple and safe alternative for children while reducing the amount of local anesthetics needed, the bleeding and the chances of infection, swelling and discomfort.

  8. Computer-assisted surgical techniques: can they really improve laser surgery?

    NASA Astrophysics Data System (ADS)

    Reinisch, Lou; Arango, Pablo; Howard, John G.; Mendenhall, Marcus H.; Ossoff, Robert H.

    1995-05-01

    As part of our Computer-Assisted Surgical Techniques (CAST) program, we use computers to guide surgical lasers, create minimal incision widths, regulate the rate of tissue ablation, monitor the types of tissue being ablated with photo-acoustic feedback, and track and compensate for patient motions due to respiration and heart beat. The union of the computer, robotics and lasers can assist the surgeon and permit several new applications. Although these advances in laser surgery appear to have obvious benefits, it is important to evaluate and quantify the clinical advantages. We have compared the CAST system to manually controlled laser surgery and studied the wound healing after laser incision. We have found definite advantages to the CAST system. However, the computer, alone, cannot compensate for the thermal damage lateral to the incision site. The results suggest the need for motion tracking and compensation to be a part of the CAST system.

  9. Indocyanine Green Fluorescence Imaging in the Surgical Management of an Iatrogenic Lymphatic Fistula: Description of a Surgical Technique.

    PubMed

    Papadia, Andrea; Imboden, Sara; Mohr, Stefan; Lanz, Susanne; Nirgianakis, Konstantinos; Mueller, Michael D

    2015-01-01

    We present a case of laparoscopic surgical management of an iatrogenic lymphorrhea using indocyanine green (ICG). A case of a patient who developed recurrent symptomatic lymphorrhea after laparoscopic radical hysterectomy and bilateral pelvic lymphadenectomy for an early stage cervical cancer is presented. Intraoperative bipedal interdigital subcutaneous injection of ICG exactly localized the disrupted lymphatic duct on fluorescence imaging performed with a near-infrared laparoscopic fluorescent optic device, thus allowing a successful surgical repair.

  10. The analytical representation of viscoelastic material properties using optimization techniques

    NASA Astrophysics Data System (ADS)

    Hill, S. A.

    1993-02-01

    This report presents a technique to model viscoelastic material properties with a function of the form of the Prony series. Generally, the method employed to determine the function constants requires assuming values for the exponential constants of the function and then resolving the remaining constants through linear least-squares techniques. The technique presented here allows all the constants to be analytically determined through optimization techniques. This technique is employed in a computer program named PRONY and makes use of commercially available optimization tool developed by VMA Engineering, Inc. The PRONY program was utilized to compare the technique against previously determined models for solid rocket motor TP-H1148 propellant and V747-75 Viton fluoroelastomer. In both cases, the optimization technique generated functions that modeled the test data with at least an order of magnitude better correlation. This technique has demonstrated the capability to use small or large data sets and to use data sets that have uniformly or nonuniformly spaced data pairs. The reduction of experimental data to accurate mathematical models is a vital part of most scientific and engineering research. This technique of regression through optimization can be applied to other mathematical models that are difficult to fit to experimental data through traditional regression techniques.

  11. Chondroblastoma of the femoral head disrupting the articular cartilage. Description of a novel surgical technique.

    PubMed

    Givissis, Panagiotis; Agathangelidis, Filon; Christodoulou, Evangelos; Christodoulou, Anastasios

    2012-06-01

    Chondroblastoma is a rare benign tumour. Involvement of the femoral head may often lead to a delayed diagnosis. We present the case of a 15-year-old patient with right hip pain which was first attributed to adductor tendinitis. Following aggravation of the symptoms, thorough investigation including a CT-guided biopsy, revealed the diagnosis of chondroblastoma of the femoral head. Removal of the lesion based on the techniques described in literature was not possible, mainly because the articular cartilage was breached. A novel surgical technique was used in order to address the rare location and behaviour of the tumour. This technique offered the patient pain relief and return to his previous every day and sports activities. No recurrence was seen at two years follow-up.

  12. A Novel Surgical Pre-suturing Technique for the Management of Ankyloglossia

    PubMed Central

    Khairnar, Mayur; Pawar, Babita; Khairnar, Darshana

    2014-01-01

    Ankyloglossia or “tongue-tie” is a congenital anomaly caused by tight lingual frenulum that abnormally connects the tongue base to the floor of the mouth. Ankyloglossia can results in difficulty during speech and deglutition. This case series presents a novel surgical technique in the management of ankyloglossia in using presuturing technique in which different sets of sutures are given on lingual frenum before severing it. This results in reduced opening of the wound, minimal bleeding, pain and discomfort. Two male patients with severe ankyloglossia had been managed with this technique and after 2 years of follow-up of these cases showed satisfactory protrusive and lateral movement of the tongue with minimal scarring and discomfort. PMID:25598942

  13. Chondroblastoma of the femoral head disrupting the articular cartilage. Description of a novel surgical technique.

    PubMed

    Givissis, Panagiotis; Agathangelidis, Filon; Christodoulou, Evangelos; Christodoulou, Anastasios

    2012-06-01

    Chondroblastoma is a rare benign tumour. Involvement of the femoral head may often lead to a delayed diagnosis. We present the case of a 15-year-old patient with right hip pain which was first attributed to adductor tendinitis. Following aggravation of the symptoms, thorough investigation including a CT-guided biopsy, revealed the diagnosis of chondroblastoma of the femoral head. Removal of the lesion based on the techniques described in literature was not possible, mainly because the articular cartilage was breached. A novel surgical technique was used in order to address the rare location and behaviour of the tumour. This technique offered the patient pain relief and return to his previous every day and sports activities. No recurrence was seen at two years follow-up. PMID:22822587

  14. A systematic review on skin complications of bone-anchored hearing aids in relation to surgical techniques.

    PubMed

    Mohamad, Shwan; Khan, Imran; Hey, S Y; Hussain, S S Musheer

    2016-03-01

    A systematic review to study the skin complications associated with the bone-anchored hearing aid in relation to surgical techniques. The following databases have been searched: MEDLINE, EMBASE, the Cochrane Library , Google scholar and the PubMed. The literature search date was from January 1977 until November 2013. Randomised controlled trials and retrospective studies were included. Initial search identified 420 publications. Thirty articles met the inclusion criteria of this review. The most common surgical techniques identified were full-thickness skin graft, Dermatome and linear incision techniques. The result shows that dermatome technique is associated with higher rate of skin complications when compared to linear incision and skin graft techniques. Based on the available literature, the use of a linear incision technique appears to be associated with lower skin complications; however, there is limited data available supporting this. Higher quality studies would allow a more reliable comparison between the surgical techniques.

  15. Surgical approach to right colon cancer: From open technique to robot. State of art

    PubMed Central

    Fabozzi, Massimiliano; Cirillo, Pia; Corcione, Francesco

    2016-01-01

    This work is a topic highlight on the surgical treatment of the right colon pathologies, focusing on the literature state of art and comparing the open surgery to the different laparoscopic and robotic procedures. Different laparoscopic procedures have been described for the treatment of right colon tumors: Totally laparoscopic right colectomy, laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy, single incision laparoscopic surgery colectomy, robotic right colectomy. Two main characteristics of these techniques are the different type of anastomosis: Intracorporeal (for totally laparoscopic right colectomy, single incision laparoscopic surgery colectomy, laparoscopic assisted right colectomy and robotic technique) or extracorporeal (for laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy and open right colectomy) and the different incision (suprapubic, median or transverse on the right side of abdomen). The different laparoscopic techniques meet the same oncological criteria of radicalism as the open surgery for the right colon. The totally laparoscopic right colectomy with intracorporeal anastomosis and even more the single incision laparoscopic surgery colectomy, remain a technical challenge due to the complexity of procedures (especially for the single incision laparoscopic surgery colectomy) and the particular right colon vascular anatomy but they seem to have some theoretical advantages compared to the other laparoscopic and open procedures. Data reported in literature while confirming the advantages of laparoscopic approach, do not allow to solve controversies about which is the best laparoscopic technique (Intracorporeal vs Extracorporeal Anastomosis) to treat the right colon cancer. However, the laparoscopic techniques with intracorporeal anastomosis for the right colon seem to show some theoretical advantages (functional, technical

  16. Surgical approach to right colon cancer: From open technique to robot. State of art

    PubMed Central

    Fabozzi, Massimiliano; Cirillo, Pia; Corcione, Francesco

    2016-01-01

    This work is a topic highlight on the surgical treatment of the right colon pathologies, focusing on the literature state of art and comparing the open surgery to the different laparoscopic and robotic procedures. Different laparoscopic procedures have been described for the treatment of right colon tumors: Totally laparoscopic right colectomy, laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy, single incision laparoscopic surgery colectomy, robotic right colectomy. Two main characteristics of these techniques are the different type of anastomosis: Intracorporeal (for totally laparoscopic right colectomy, single incision laparoscopic surgery colectomy, laparoscopic assisted right colectomy and robotic technique) or extracorporeal (for laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy and open right colectomy) and the different incision (suprapubic, median or transverse on the right side of abdomen). The different laparoscopic techniques meet the same oncological criteria of radicalism as the open surgery for the right colon. The totally laparoscopic right colectomy with intracorporeal anastomosis and even more the single incision laparoscopic surgery colectomy, remain a technical challenge due to the complexity of procedures (especially for the single incision laparoscopic surgery colectomy) and the particular right colon vascular anatomy but they seem to have some theoretical advantages compared to the other laparoscopic and open procedures. Data reported in literature while confirming the advantages of laparoscopic approach, do not allow to solve controversies about which is the best laparoscopic technique (Intracorporeal vs Extracorporeal Anastomosis) to treat the right colon cancer. However, the laparoscopic techniques with intracorporeal anastomosis for the right colon seem to show some theoretical advantages (functional, technical

  17. Surgical approach to right colon cancer: From open technique to robot. State of art.

    PubMed

    Fabozzi, Massimiliano; Cirillo, Pia; Corcione, Francesco

    2016-08-27

    This work is a topic highlight on the surgical treatment of the right colon pathologies, focusing on the literature state of art and comparing the open surgery to the different laparoscopic and robotic procedures. Different laparoscopic procedures have been described for the treatment of right colon tumors: Totally laparoscopic right colectomy, laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy, single incision laparoscopic surgery colectomy, robotic right colectomy. Two main characteristics of these techniques are the different type of anastomosis: Intracorporeal (for totally laparoscopic right colectomy, single incision laparoscopic surgery colectomy, laparoscopic assisted right colectomy and robotic technique) or extracorporeal (for laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy and open right colectomy) and the different incision (suprapubic, median or transverse on the right side of abdomen). The different laparoscopic techniques meet the same oncological criteria of radicalism as the open surgery for the right colon. The totally laparoscopic right colectomy with intracorporeal anastomosis and even more the single incision laparoscopic surgery colectomy, remain a technical challenge due to the complexity of procedures (especially for the single incision laparoscopic surgery colectomy) and the particular right colon vascular anatomy but they seem to have some theoretical advantages compared to the other laparoscopic and open procedures. Data reported in literature while confirming the advantages of laparoscopic approach, do not allow to solve controversies about which is the best laparoscopic technique (Intracorporeal vs Extracorporeal Anastomosis) to treat the right colon cancer. However, the laparoscopic techniques with intracorporeal anastomosis for the right colon seem to show some theoretical advantages (functional, technical

  18. Surgical approach to right colon cancer: From open technique to robot. State of art.

    PubMed

    Fabozzi, Massimiliano; Cirillo, Pia; Corcione, Francesco

    2016-08-27

    This work is a topic highlight on the surgical treatment of the right colon pathologies, focusing on the literature state of art and comparing the open surgery to the different laparoscopic and robotic procedures. Different laparoscopic procedures have been described for the treatment of right colon tumors: Totally laparoscopic right colectomy, laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy, single incision laparoscopic surgery colectomy, robotic right colectomy. Two main characteristics of these techniques are the different type of anastomosis: Intracorporeal (for totally laparoscopic right colectomy, single incision laparoscopic surgery colectomy, laparoscopic assisted right colectomy and robotic technique) or extracorporeal (for laparoscopic assisted right colectomy, laparoscopic facilitated right colectomy, hand-assisted right colectomy and open right colectomy) and the different incision (suprapubic, median or transverse on the right side of abdomen). The different laparoscopic techniques meet the same oncological criteria of radicalism as the open surgery for the right colon. The totally laparoscopic right colectomy with intracorporeal anastomosis and even more the single incision laparoscopic surgery colectomy, remain a technical challenge due to the complexity of procedures (especially for the single incision laparoscopic surgery colectomy) and the particular right colon vascular anatomy but they seem to have some theoretical advantages compared to the other laparoscopic and open procedures. Data reported in literature while confirming the advantages of laparoscopic approach, do not allow to solve controversies about which is the best laparoscopic technique (Intracorporeal vs Extracorporeal Anastomosis) to treat the right colon cancer. However, the laparoscopic techniques with intracorporeal anastomosis for the right colon seem to show some theoretical advantages (functional, technical

  19. Reconstruction of medial patello-femoral ligament: Comparison of two surgical techniques.

    PubMed

    Criscenti, G; De Maria, C; Sebastiani, E; Tei, M; Placella, G; Speziali, A; Vozzi, G; Cerulli, G

    2016-06-01

    The medial patello-femoral ligament is considered the most important passive patellar stabilizer and its proper functionality is essential for the patello-femoral joint stability. In this work, 18 human knees were randomly divided into two groups and reconstructed through two different surgical techniques: the "Through tunnel tendon" and the "Double converging tunnel" reconstructions. Subsequently, the samples were mechanically tested to evaluate the structural properties of reconstructed femur-MPFL-Patella complex (rFMPC). Particular attention was given to maintain the anatomical orientation between the patella and the graft. Both procedures showed lower stiffness and higher ultimate strain and absorbed energy compared to the native MPFL, but the advantages of the double converging tunnel technique are related to the restoration of the native MPFL sail-shape, to a better stress distribution on the patella, to the use of a single interference screw as fixation device and to the simplicity, rapidity and cost-effectivity of the surgical procedure. The evaluation of the structural properties of rMPFL is fundamental to evaluate the adequacy of the different techniques to restore the physiological structural properties of the native MPFL. PMID:26894660

  20. Surface optimization technique for MammoSite breast brachytherapy applicator

    SciTech Connect

    Kirk, Michael . E-mail: Michael_C_Kirk@rush.edu; Hsi, W.C.; Dickler, Adam; Chu, James; Dowlatshahi, Kambiz; Francescatti, Darius; Nguyen, Cam

    2005-06-01

    Purpose: We present a technique to optimize the dwell times and positions of a high-dose-rate {sup 192}Ir source using the MammoSite breast brachytherapy applicator. The surface optimization method used multiple dwell positions and optimization points to conform the 100% isodose line to the surface of the planning target volume (PTV). Methods and materials: The study population consisted of 20 patients treated using the MammoSite device between October 2002 and February 2004. Treatment was delivered in 10 fractions of 3.4 Gy/fraction, twice daily, with a minimum of 6 h between fractions. The treatment of each patient was planned using three optimization techniques. The dosimetric characteristics of the single-point, six-point, and surface optimization techniques were compared. Results: The surface optimization technique increased the PTV coverage compared with the single- and six-point methods (mean percentage of PTV receiving 100% of the prescription dose was 94%, 85%, and 91%, respectively). The surface method, single-point, and six-point method had a mean dose homogeneity index of 0.62, 0.68, and 0.63 and a mean full width at half maximum value of 189, 190, and 192 cGy/fraction, respectively. Conclusion: The surface technique provided greater coverage of the PTV than did the single- and six-point methods. Using the FWHM method, the surface, single-, and six-point techniques resulted in equivalent dose homogeneity.

  1. Case Report: ALCAPA syndrome: successful repair with an anatomical and physiological alternative surgical technique

    PubMed Central

    Vilá Mollinedo, Luis Gustavo; Jaime Uribe, Andrés; Aceves Chimal, José Luis; Martínez-Rubio, Roberto Pablo; Hernández-Romero, Karen Patricia

    2016-01-01

    Anomalous left coronary artery from the pulmonary artery, or ALCAPA syndrome, is a rare congenital cardiac disease that can cause myocardial infarction, heart failure and even death in paediatric patients. Only few untreated patients survive until adult age. Here we present the case of a 33-year-old female patient with paroxysmal tachycardia, syncope and mild exertional dyspnoea. She was diagnosed with ALCAPA syndrome and underwent surgical correction with an alternative technique of left main coronary artery extension to the aorta. PMID:27547381

  2. Lateralization of the inferior alveolar nerve with simultaneous implant placement: surgical techniques.

    PubMed

    Garg, A K; Morales, M J

    1998-01-01

    In the event of moderate to severe mandibular bone resorption posterior to the mental foramen, repositioning of the inferior alveolar nerve provides a greater amount of available bone for implant placement and reduces the risk of nerve injury. While neural paresthesia may initially occur, this altered sensation generally resolves spontaneously. Alveolar nerve repositioning may be possible in cases in which other procedures cannot be performed due to the extent of atrophy of the posterior mandibular alveolar crest. This article presents the surgical technique to achieve this objective. PMID:10093565

  3. Case Report: ALCAPA syndrome: successful repair with an anatomical and physiological alternative surgical technique.

    PubMed

    Vilá Mollinedo, Luis Gustavo; Jaime Uribe, Andrés; Aceves Chimal, José Luis; Martínez-Rubio, Roberto Pablo; Hernández-Romero, Karen Patricia

    2016-01-01

    Anomalous left coronary artery from the pulmonary artery, or ALCAPA syndrome, is a rare congenital cardiac disease that can cause myocardial infarction, heart failure and even death in paediatric patients. Only few untreated patients survive until adult age. Here we present the case of a 33-year-old female patient with paroxysmal tachycardia, syncope and mild exertional dyspnoea. She was diagnosed with ALCAPA syndrome and underwent surgical correction with an alternative technique of left main coronary artery extension to the aorta. PMID:27547381

  4. Evaluation of a training course on open vascular surgical techniques in aortoiliac pathology - 5 years of experience

    PubMed Central

    STANCU, BOGDAN; BETEG, FLORIN; MIRONIUC, AUREL; MUSTE, AUREL; GHERMAN, CLAUDIA

    2015-01-01

    Introduction The aim of this prospective study was to assess the efficacy of a vascular surgery course (2008–2012), and to verify the viability and the feasibility of vascular anastomoses. Material and method The vascular surgical techniques performed simultaneously on pigs were: enlargement prosthetic angioplasty, abdominal aortic interposition graft and aortoiliac bypass. The endpoints of the study were the surgical skills and the technical quality, assessed on a scale ranging from 1 (satisfactory) to 3 (very good) for our participants. Results A significant improvement in vascular surgical skills tasks was observed during the study years and we also found a significant statistical association between the quality of the suture and the surgical technique used (Kendall coefficient=0.71, p=0.001<0.05). Conclusions Our course contributed to the improvement of the technical vascular surgical skills of the operator teams, reproducing in vivo, in pigs, the intraoperative environment of human patients. PMID:26528071

  5. The “excluding” suture technique for surgical closure of ventricular septal defects: A retrospective study comparing the standard technique

    PubMed Central

    Varghese, Roy; Saheed, Sanni; Ravi, Amrutha K; Sherrif, Ejaz Ahmed; Agarwal, Ravi; Kothandam, Sivakumar

    2016-01-01

    Background: Conventional methods of closure of ventricular septal defects involve placement of sutures 4-5 mm from the posterior inferior margin. This study compares the conventional method with an alternative technique wherein sutures are placed along the edge of the defect thereby “excluding” the conduction system and the tensor apparatus of the tricuspid valve from the suture line. Materials and Methods: Between January 2013 and January 2016, 409 consecutive patients were retrospectively reviewed and divided into two matched groups. Group A (n = 174) underwent closure using the alternative technique and Group B (n = 235) with the conventional technique. Patients with isolated ventricular septal defects (VSDs) (n = 136) were separately analyzed as were infants within this subset. Results: Immediate postoperative results were similar with no statistically significant differences in either group in terms of incidence of residual defects or postoperative tricuspid regurgitation. There was however a significantly increased incidence of post operative complete heart block (CHB) among patients in the conventional group (P = 0.02). Incidence of temporary heart block that reverted to sinus rhythm was also more in the conventional method group (Group B) (P = 0.03) as was right bundle branch block (P ≤ 0.05) in all the subsets of patients analyzed. Conclusion: Surgical closure of VSDs can be accomplished by placing sutures along the margins or away with comparable results. The incidence of CHB, however, seems to be less when the “excluding” technique is employed.

  6. The “excluding” suture technique for surgical closure of ventricular septal defects: A retrospective study comparing the standard technique

    PubMed Central

    Varghese, Roy; Saheed, Sanni; Ravi, Amrutha K; Sherrif, Ejaz Ahmed; Agarwal, Ravi; Kothandam, Sivakumar

    2016-01-01

    Background: Conventional methods of closure of ventricular septal defects involve placement of sutures 4-5 mm from the posterior inferior margin. This study compares the conventional method with an alternative technique wherein sutures are placed along the edge of the defect thereby “excluding” the conduction system and the tensor apparatus of the tricuspid valve from the suture line. Materials and Methods: Between January 2013 and January 2016, 409 consecutive patients were retrospectively reviewed and divided into two matched groups. Group A (n = 174) underwent closure using the alternative technique and Group B (n = 235) with the conventional technique. Patients with isolated ventricular septal defects (VSDs) (n = 136) were separately analyzed as were infants within this subset. Results: Immediate postoperative results were similar with no statistically significant differences in either group in terms of incidence of residual defects or postoperative tricuspid regurgitation. There was however a significantly increased incidence of post operative complete heart block (CHB) among patients in the conventional group (P = 0.02). Incidence of temporary heart block that reverted to sinus rhythm was also more in the conventional method group (Group B) (P = 0.03) as was right bundle branch block (P ≤ 0.05) in all the subsets of patients analyzed. Conclusion: Surgical closure of VSDs can be accomplished by placing sutures along the margins or away with comparable results. The incidence of CHB, however, seems to be less when the “excluding” technique is employed. PMID:27625520

  7. Optimization of detector positioning in the radioactive particle tracking technique.

    PubMed

    Dubé, Olivier; Dubé, David; Chaouki, Jamal; Bertrand, François

    2014-07-01

    The radioactive particle tracking (RPT) technique is a non-intrusive experimental velocimetry and tomography technique extensively applied to the study of hydrodynamics in a great variety of systems. In this technique, arrays of scintillation detector are used to track the motion of a single radioactive tracer particle emitting isotropic γ-rays. This work describes and applies an optimization strategy developed to find an optimal set of positions for the scintillation detectors used in the RPT technique. This strategy employs the overall resolution of the detectors as the objective function and a mesh adaptive direct search (MADS) algorithm to solve the optimization problem. More precisely, NOMAD, a C++ implementation of the MADS algorithm is used. First, the optimization strategy is validated using simple cases with known optimal detector configurations. Next, it is applied to a three-dimensional axisymmetric system (i.e. a vertical cylinder, which could represent a fluidized bed, bubble column, riser or else). The results obtained using the optimization strategy are in agreement with what was previously recommended by Roy et al. (2002) for a similar system. Finally, the optimization strategy is used for a system consisting of a partially filled cylindrical tumbler. The application of insights gained by the optimization strategy is shown to lead to a significant reduction in the error made when reconstructing the position of a tracer particle. The results of this work show that the optimization strategy developed is sensitive to both the type of objective function used and the experimental conditions. The limitations and drawbacks of the optimization strategy are also discussed.

  8. Intradural Intramedullary Mixed Type Hemangioma: Optimizing the Surgical Management through Intraoperative Neurophysiological Monitoring

    PubMed Central

    Rahyussalim, Ahmad Jabir; Situmeang, Adrian; Safri, Ahmad Yanuar; Fadhly, Zulfa Indah K.

    2015-01-01

    Intradural intramedullary mixed type hemangioma is a rare histotype of primary spinal cord tumors, though it can carry a severe clinical burden leading to limb dysfunction or motor and sensory disturbances. Timely intervention with radical resection is the hallmark of treatment but achieving it is not an easy task even for experienced neurosurgeons. We herein present an exemplificative case presenting with sudden paraplegia in which total resection was achieved under intraoperative neurophysiology monitoring. A thorough discussion on the operative technique and the role of neuromonitoring in allowing a safe surgical management of primary spinal cord tumors is presented. PMID:26839729

  9. Surgical treatment of iliotibial band friction syndrome with the mesh technique.

    PubMed

    Sangkaew, Chanchit

    2007-05-01

    Iliotibial band friction syndrome is an overuse injury caused by repetitive friction of the iliotibial band across the lateral femoral epicondyle. It has been reported to afflict long-distance runners, cyclists and military personnel. Initial treatments include rest, anti-inflammatory medication, modalities (ice or heat), stretching, physical therapy, and possibly a corticosteroid injection. If the conservative treatment is unsuccessful, surgery has been advocated. This report describes a new surgical technique to release the pressure on the lateral femoral epicondyle in a patient who failed the nonoperative efforts. The surgery was performed with the knee held in 30 degrees of flexion and consisted of multiple 2 mm long incisions across the fiber of the iliotibial band covering the lateral femoral epicondyle. There were six incisions, each of which was 4 mm apart. The incisions were spontaneously enlarged and changed to several punctured wounds (mesh appearance) by the tension of iliotibial band, resulted in relaxing the tight iliotibial band over the lateral femoral epicondyle. At the final follow-up 2 years after surgery the patient was pain free and could resume his previous occupational activities. The surgical result of the present technique is encouraging.

  10. Laparoscopic vasectomy in African savannah elephant (Loxodonta africana); surgical technique and results.

    PubMed

    Marais, Hendrik J; Hendrickson, Dean A; Stetter, Mark; Zuba, Jeffery R; Penning, Mark; Siegal-Willott, Jess; Hardy, Christine

    2013-12-01

    Several small, enclosed reserves in southern Africa are experiencing significant elephant population growth, which has resulted in associated environmental damage and changes in biodiversity. Although several techniques exist to control elephant populations, e.g., culling, relocation, and immunocontraception, the technique of laparoscopic vasectomy of free-ranging bull elephants was investigated. Bilateral vasectomies were performed in 45 elephants. Of these elephants, one died within 24 hr of recovery and two had complications during surgery but recovered uneventfully. Histologic examination confirmed the resected tissue as ductus deferens in all the bulls. Most animals recovered uneventfully and showed no abnormal behavior after surgery. Complications recorded included incisional dehiscence, 1 full-thickness and 2 partial-thickness lacerations of the large intestine, and initial sling-associated complications, for example, deep radial nerve paresis. One bull was found dead 6 weeks after surgery without showing any prior abnormal signs. Vasectomy in free-ranging African bull elephants may be effectively performed in their normal environment. The surgical procedure can be used as a realistic population management tool in free-ranging elephants without major anesthetic, surgical, or postoperative complications.

  11. Surgical Treatment of Iatrogenic Ventral Glottic Stenosis Using a Mucosal Flap Technique

    PubMed Central

    Barnett, Timothy P.; O'Leary, John Mark; Dixon, Padraic M.

    2016-01-01

    Objective To describe a novel surgical technique for correcting postoperative ventral glottic stenosis (cicatrix or web formation) and the outcome in 2 Thoroughbred racehorses. Study Design Retrospective case report. Animals Thoroughbreds diagnosed with ventral glottic stenosis (n=2). Methods Horses presenting with iatrogenic ventral glottic stenosis and resultant exercise intolerance and abnormal exercise‐related noise were anesthetized and a midline sagittal skin incision was made over the ventral larynx and between the sternohyoideus muscles overlying the cricothyroid notch. The cricothyroid ligament, attached laryngeal cicatrix, and overlying mucosa were sagittally sectioned at the dorsal aspect of the cicatrix on the left side. The laryngeal mucosa, cicatrix, and underlying cricothyroid ligament immediately rostral and caudal to the cicatrix were sectioned in a medial (axial) direction as far as the right side of the cricothyroid notch. After resection of the majority of the attached cicatrix tissue, the residual mucosal flap (attached to the right side of the larynx) was reflected ventrally and sutured to the attachment of the cricothyroid ligament on the right side of the cricothyroid notch, creating an intact mucosal layer on the right side of the ventral larynx. Results Both horses had good intralaryngeal wound healing with minimal redevelopment of ventral glottic stenosis at 5 and 9 months postoperatively and were successfully returned to racing with complete absence of abnormal respiratory noise. Conclusion The unique laryngeal anatomy of horses, with a cartilage‐free ventral laryngeal area (cricothyroid notch), allowed the use of this novel surgical technique to successfully treat ventral glottic stenosis. PMID:27013024

  12. Laparoscopic vasectomy in African savannah elephant (Loxodonta africana); surgical technique and results.

    PubMed

    Marais, Hendrik J; Hendrickson, Dean A; Stetter, Mark; Zuba, Jeffery R; Penning, Mark; Siegal-Willott, Jess; Hardy, Christine

    2013-12-01

    Several small, enclosed reserves in southern Africa are experiencing significant elephant population growth, which has resulted in associated environmental damage and changes in biodiversity. Although several techniques exist to control elephant populations, e.g., culling, relocation, and immunocontraception, the technique of laparoscopic vasectomy of free-ranging bull elephants was investigated. Bilateral vasectomies were performed in 45 elephants. Of these elephants, one died within 24 hr of recovery and two had complications during surgery but recovered uneventfully. Histologic examination confirmed the resected tissue as ductus deferens in all the bulls. Most animals recovered uneventfully and showed no abnormal behavior after surgery. Complications recorded included incisional dehiscence, 1 full-thickness and 2 partial-thickness lacerations of the large intestine, and initial sling-associated complications, for example, deep radial nerve paresis. One bull was found dead 6 weeks after surgery without showing any prior abnormal signs. Vasectomy in free-ranging African bull elephants may be effectively performed in their normal environment. The surgical procedure can be used as a realistic population management tool in free-ranging elephants without major anesthetic, surgical, or postoperative complications. PMID:24437080

  13. Endoscopic treatment of the external snapping hip syndrome: surgical technique and report of two cases.

    PubMed

    Kunac, Nino; Trsek, Denis; Medancić, Nenad; Starcević, Damir; Haspl, Miroslav

    2012-12-01

    Snapping hip or coxa saltans is a condition characterized by an audible and/or palpable snapping during hip movement and can be associated with pain around the hip. There are various causes of this condition and can be divided into two types: extra-articular and intra-articular. The most common type is the external extra-articular, where the snapping is due to thickened posterior part of the iliotibial band or anterior part of the gluteus maximus muscle sliding over the greater trochanter during hip movement. Two patients with external snapping hip are presented, who were treated with our original endoscopic iliotibial band release and greater trochanteric bursectomy. There were no surgical complications and the patients did not experience snapping or pain in the hip during 24-month follow-up period. Results of various open techniques and one endoscopic technique in the treatment of external snapping hip are also reported. PMID:23540176

  14. Treatment planning for colorectal cancer: radiation and surgical techniques and value of small-bowel films

    SciTech Connect

    Gunderson, L.L.; Russell, A.H.; Llewellyn, H.J.; Doppke, K.P.; Tepper, J.E.

    1985-07-01

    For colorectal cancer, the adjuvant radiation dose levels required to achieve a high incidence of local control closely parallel the radiation tolerance of small bowel (4500-5000 rad), and for patients with partially resected or unresected disease, the dose levels exceed tolerance (6000-7000 rad). Therefore, both the surgeon and the radiation oncologist should use techniques that localize tumor volumes and decrease the amount of small intestine within the irradiation field. Surgical options include pelvic reconstruction and clip placement. Radiation options include the use of radiographs to define small bowel location and mobility combined with treatment techniques using multiple fields, bladder distention, shrinking or boost fields, and/or patient position changes. When both specialties interact in optimum fashion, local control can be increased with minimal side effects to the small intestine.

  15. [Transcutaneous excision of the submandibular and sublingual glands: notes on anatomy and surgical technique].

    PubMed

    Fornaro, Rosario; Frascio, Marco; Stabilini, Cesare; Ricci, Barbara; Mandolfino, Francesca; Sticchi, Camilla; Gianetta, Ezio

    2007-01-01

    Removal of the submandibular and sublingual glands requires in-depth knowledge of the anatomy and scrupulous technique for the purposes of limiting the functional and aesthetic damage, which is unjustifiable above all in the treatment of benign lesions (sialodenitis, lithiasis). After presenting the main aspects of the surgical anatomy of the submandibular space, the operative technique for its dissection with removal of the submandibular gland and excision of the sublingual gland is described. The complexity of the anatomical structures that may be involved in submandibular and sublingual gland lesions is the cause of unsatisfactory functional and aesthetic outcomes in some cases. The most feared complications are lesions to nerve formations, due both to the resulting deficits and the possible legal implications.

  16. A comparison of two anesthesia methods for the surgical removal of maxillary third molars: PSA nerve block technique vs. local infiltration technique

    PubMed Central

    2014-01-01

    Objectives: The purpose of this study was to compare the effect of PSA block injection with infiltration technique regarding local anesthesia for surgical extraction of upper third molar. Material and Methods: A prospective, intra individual, single-blind randomized controlled trial was designed to study the severity of pain during injection and after surgical extraction of the bilaterally and symmetrically similar upper third molar in a total of 53 patients, in addition to evaluating the need to repeat the injection and requirement of post operative anti-inflammatory tablets. Result: Although the average pain score for all studied times in PSA side was lower than the average pain score in infiltration technique, repeated statistical measures demonstrated that no significant pain reduction occurred in the two techniques. Conclusion: The both tested methods have the same statistic equivalence for the surgical extraction of maxillary third molars. Key words:Surgical extraction, maxillary third molars, PSA block, infiltration. PMID:24596629

  17. A Comparison of Three C-Arm Draping Techniques to Minimize Contamination of the Surgical Field.

    PubMed

    Gershkovich, Grigory E; Tiedeken, Nathan C; Hampton, David; Budacki, Ross; Samuel, Solomon P; Saing, Minn

    2016-10-01

    The use of intraoperative fluoroscopy has become a routine and useful adjunct within orthopaedic surgery. However, the fluoroscopy machine may become an additional source of contamination in the operating room, particularly when maneuvering from the anterior-posterior position to the lateral position. Consequently, draping techniques were developed to maintain sterility of the operative field and surgeon. Despite a variety of methods, no studies exist to compare the sterility of these techniques specifically when the fluoroscopy machine is in the lateral imaging position. We evaluated the sterility of 3 c-arm draping techniques in a simulated operative environment. The 3 techniques consisted of a traditional 3-quarter sterile sheet attached to the side of the operative table, a modified clip-drape method, and a commercially available sterile pouch. Our study demonstrated that the traditional method poses a high risk for sterile field contamination, whereas the modified clip-drape method and commercially available sterile pouch kept floor contamination furthest from the surgical field. With the current data, we urge surgeons to use modified techniques rather than the traditional draping method.

  18. ARTHROSCOPIC RELEASE OF THE SUPRASCAPULAR NERVE: SURGICAL TECHNIQUE AND EVALUATION OF CLINICAL CASES

    PubMed Central

    Garcia Júnior, José Carlos; Paccola, Ana Maria Ferreira; Tonoli, Cristiane; Zabeu, José Luis Amin; Garcia, Jesely Pereira Myrrha

    2015-01-01

    To describe a specific surgical technique for arthroscopic decompression of the suprascapular nerve (SSN) and evaluate its preliminary results. Methods: Ten shoulders of nine patients were operated using a technique with portals differing from the already-known techniques, which did not use traction and made use of materials available within the public healthcare system. Results: Among the ten shoulders of nine patients, eight were right shoulders and two were left shoulders. The mean age was 69.5 years. The UCLA score increased from 11.7 to 26.1 points over the postoperative follow-up of 16.6 months. The SF-36 questionnaire score was 122.9 and the raw pain scale value was 88%. Conclusion: Arthroscopic decompression of the SSN in accordance with the described technique is reproducible and less traumatic than the open techniques. The patients achieved improvements in many of the parameters evaluated, particularly with regard to pain. Arthroscopic decompression of the SSN may be a therapeutic option for pathological compression of the SSN. PMID:27027028

  19. The Optimal Surgical Approach for Treatment of Chronic Subdural Hematoma: Questionnaire Assessment of Practice in Iran and Review of Literature.

    PubMed

    Javadi, Seyed Amir Hossein; Naderi, Fereshteh; Javadi, Amir Mohammad

    2015-10-01

    Chronic subdural hematoma (CSDH) is a curable entity frequently encountered by neurosurgeons. The present study was conducted to explore expert opinion and common practice in Iran. Besides, a Review of randomized clinical trials in literature was performed. A questionnaire including six questions discussing major aspects of practice on CSDH, with multiple choices was designed. A pilot study was performed for reliability analysis of the questionnaire. A total of 100 neurosurgeons were selected randomly from the members of Iranian Association of Neurological Surgeons. Frequency of answers to each item, differences in response rates and correlation of various categories were analyzed using Chi-square statistics. The mean duration of experience was 15.4 ± 5 years, with a range of 10 to 37 years. The most common initial procedure of choice was burr-hole drainage (64%). At recurrent cases, surgical approach was changed to craniotomy at one-third of those treated initially with burr-hole drainage. The participants believed that surgical technique was predictive of outcome and recurrence. Burr-hole without drainage was used by less expert neurosurgeons (mean 12.5 ± 6), however, burr-hole drainage was the dominant technique at more than 15 years of experience and craniectomy was used only by participants with more than 30 years of experience (10%). Irrigation was used by most of the neurosurgeons (87.5%) in combination with drainage and burr-hole. The majority of participants used flat position at the postoperative period. At the current study, the pattern of management for CSDH was similar to other reports at literature suggesting the burr-hole drainage and irrigation as optimal treatment. Individualized decision-making could be made at challenging cases. PMID:26615373

  20. Process sequence optimization for digital microfluidic integration using EWOD technique

    NASA Astrophysics Data System (ADS)

    Yadav, Supriya; Joyce, Robin; Sharma, Akash Kumar; Sharma, Himani; Sharma, Niti Nipun; Varghese, Soney; Akhtar, Jamil

    2016-04-01

    Micro/nano-fluidic MEMS biosensors are the devices that detects the biomolecules. The emerging micro/nano-fluidic devices provide high throughput and high repeatability with very low response time and reduced device cost as compared to traditional devices. This article presents the experimental details for process sequence optimization of digital microfluidics (DMF) using "electrowetting-on-dielectric" (EWOD). Stress free thick film deposition of silicon dioxide using PECVD and subsequent process for EWOD techniques have been optimized in this work.

  1. The utilization of six sigma and statistical process control techniques in surgical quality improvement.

    PubMed

    Sedlack, Jeffrey D

    2010-01-01

    Surgeons have been slow to incorporate industrial reliability techniques. Process control methods were applied to surgeon waiting time between cases, and to length of stay (LOS) after colon surgery. Waiting times between surgeries were evaluated by auditing the operating room records of a single hospital over a 1-month period. The medical records of 628 patients undergoing colon surgery over a 5-year period were reviewed. The average surgeon wait time between cases was 53 min, and the busiest surgeon spent 291/2 hr in 1 month waiting between surgeries. Process control charting demonstrated poor overall control of the room turnover process. Average LOS after colon resection also demonstrated very poor control. Mean LOS was 10 days. Weibull's conditional analysis revealed a conditional LOS of 9.83 days. Serious process management problems were identified in both analyses. These process issues are both expensive and adversely affect the quality of service offered by the institution. Process control mechanisms were suggested or implemented to improve these surgical processes. Industrial reliability and quality management tools can easily and effectively identify process control problems that occur on surgical services. PMID:20946422

  2. Surgical techniques for implanting implantable cardioverter defibrillators in children and infants.

    PubMed

    Suzuki, Shoji; Motohashi, Shinya; Matsumoto, Masahiko

    2014-10-01

    Implantable cardioverter defibrillators (ICDs) are now being used in children. ICDs can be used to prevent sudden cardiac death caused by not only congenital heart defects, but also various non-structural diseases, such as long QT syndrome. However, a standard implantation technique for children, especially infants, has not yet been established. As the surgical implantation in infants is not amenable to transvenous lead placement, it was necessary to choose from epicardial, subcutaneous and pericardial ICD systems. However, many of these systems are associated with high rates of late complications. Lead fracture, insulation breakage, migration, buckling or crinkling of the patch lead and constrictive pericarditis have been reported as the most common lead-related complications. An increase in the defibrillation threshold is another issue that must be considered when using an ICD in a child or infant. Further studies on the outcomes, psychosomatic impact and other specific complications in the pediatric population need to be considered. The clinical use of ICDs in infants is still limited. Therefore, it is important to have many surgical options available so that the treatment can be custom-tailored to suit individual patients. PMID:24154922

  3. Application of optimization techniques to vehicle design: A review

    NASA Technical Reports Server (NTRS)

    Prasad, B.; Magee, C. L.

    1984-01-01

    The work that has been done in the last decade or so in the application of optimization techniques to vehicle design is discussed. Much of the work reviewed deals with the design of body or suspension (chassis) components for reduced weight. Also reviewed are studies dealing with system optimization problems for improved functional performance, such as ride or handling. In reviewing the work on the use of optimization techniques, one notes the transition from the rare mention of the methods in the 70's to an increased effort in the early 80's. Efficient and convenient optimization and analysis tools still need to be developed so that they can be regularly applied in the early design stage of the vehicle development cycle to be most effective. Based on the reported applications, an attempt is made to assess the potential for automotive application of optimization techniques. The major issue involved remains the creation of quantifiable means of analysis to be used in vehicle design. The conventional process of vehicle design still contains much experience-based input because it has not yet proven possible to quantify all important constraints. This restraint on the part of the analysis will continue to be a major limiting factor in application of optimization to vehicle design.

  4. Enhanced Multiobjective Optimization Technique for Comprehensive Aerospace Design. Part A

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Aditi; Rajadas, John N.

    1997-01-01

    A multidisciplinary design optimization procedure which couples formal multiobjectives based techniques and complex analysis procedures (such as computational fluid dynamics (CFD) codes) developed. The procedure has been demonstrated on a specific high speed flow application involving aerodynamics and acoustics (sonic boom minimization). In order to account for multiple design objectives arising from complex performance requirements, multiobjective formulation techniques are used to formulate the optimization problem. Techniques to enhance the existing Kreisselmeier-Steinhauser (K-S) function multiobjective formulation approach have been developed. The K-S function procedure used in the proposed work transforms a constrained multiple objective functions problem into an unconstrained problem which then is solved using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. Weight factors are introduced during the transformation process to each objective function. This enhanced procedure will provide the designer the capability to emphasize specific design objectives during the optimization process. The demonstration of the procedure utilizes a computational Fluid dynamics (CFD) code which solves the three-dimensional parabolized Navier-Stokes (PNS) equations for the flow field along with an appropriate sonic boom evaluation procedure thus introducing both aerodynamic performance as well as sonic boom as the design objectives to be optimized simultaneously. Sensitivity analysis is performed using a discrete differentiation approach. An approximation technique has been used within the optimizer to improve the overall computational efficiency of the procedure in order to make it suitable for design applications in an industrial setting.

  5. Towards Clinically Optimized MRI-guided Surgical Manipulator for Minimally Invasive Prostate Percutaneous Interventions: Constructive Design*

    PubMed Central

    Eslami, Sohrab; Fischer, Gregory S.; Song, Sang-Eun; Tokuda, Junichi; Hata, Nobuhiko; Tempany, Clare M.; Iordachita, Iulian

    2013-01-01

    This paper undertakes the modular design and development of a minimally invasive surgical manipulator for MRI-guided transperineal prostate interventions. Severe constraints for the MRI-compatibility to hold the minimum artifact on the image quality and dimensions restraint of the bore scanner shadow the design procedure. Regarding the constructive design, the manipulator kinematics has been optimized and the effective analytical needle workspace is developed and followed by proposing the workflow for the manual needle insertion. A study of the finite element analysis is established and utilized to improve the mechanism weaknesses under some inevitable external forces to ensure the minimum structure deformation. The procedure for attaching a sterile plastic drape on the robot manipulator is discussed. The introduced robotic manipulator herein is aimed for the clinically prostate biopsy and brachytherapy applications. PMID:24683502

  6. [Choice of optimal perfusion flow rate during surgical correction of combined acquired heart diseases].

    PubMed

    Len'kin, A I; Zakharov, V I; Smetkin, A A; Len'kin, P I; Kirov, M Iu

    2013-01-01

    Cardiac output during the use of cardiopulmonary bypass (CPB) is defined by perfusion flow rate, which is calculated by multiplying the perfusion index (PI) on the body surface area. To date, there is no clear definition of an optimal PI and flow rate of perfusion. 60 patients operated with CPB were enrolled in the prospective study to determine the relations between different modes of perfusion and oxygen transport during surgical correction of combined valvular heart disease. Calculation of the CPB flow rate was based on PI 2.5 and 3.0 l/min/m2. Results of the study demonstrate that perfusion based on PI 2.5 l/min/m2 provides more stable oxygen transport parameters and reduces the time of ICU stay in comparison with the flow rate based on PI 3.0 l/min/m2.

  7. Stochastic optimization techniques for NDE of bridges using vibration signatures

    NASA Astrophysics Data System (ADS)

    Yi, Jin-Hak; Feng, Maria Q.

    2003-08-01

    A baseline model updating is the first step for the model-based non destructive evaluation for civil infrastructures. Many researches have been drawn to obtain a more reliable baseline model. In this study, heuristic optimization techniques (or called as stochastic optimization techniques) including the genetic algorithm, the simulated annealing, and the tabu search, were have been investigated for constructing the reliable baseline model for an instrumented new highway bridge, and also were compared with the result of conventional sensitivity method. The preliminary finite element model of the bridge was successfully updated to a baseline model based on measured vibration data.

  8. A Review of Current Concepts in Flexor Tendon Repair: Physiology, Biomechanics, Surgical Technique and Rehabilitation

    PubMed Central

    Rymer, Ben; Theobald, Peter; Thomas, Peter B.M.

    2015-01-01

    Historically, the surgical treatment of flexor tendon injuries has always been associated with controversy. It was not until 1967, when the paper entitled Primary repair of flexor tendons in no man’s land was presented at the American Society of Hand Surgery, which reported excellent results and catalyzed the implementation of this technique into worldwide practice. We present an up to date literature review using PubMed and Google Scholar where the terms flexor tendon, repair and rehabilitation were used. Topics covered included functional anatomy, nutrition, biome-chanics, suture repair, repair site gapping, and rehabilitation. This article aims to provide a comprehensive and complete overview of flexor tendon repairs. PMID:26793293

  9. Minimally invasive cardiac surgery in the adult: surgical instruments, equipment, and techniques.

    PubMed

    Kitamura, M; Uwabe, K; Hirota, J; Kawai, A; Endo, M; Koyanagi, H

    1998-09-01

    To clarify the special instruments and equipment used for minimally invasive cardiac surgery (MICS), we examined the initial experiences with MICS operations with ministernotomy or minithoracotomy at our institution. Fifty adult patients with congenital, valvular, and/or ischemic heart diseases underwent MICS operations, and all surgical procedures were completed without conversion to full sternotomy. The length of the skin incision was about 10 cm or less in all patients. Postoperative recovery was favorable, and the majority of the patients were discharged from the hospital around the end of the second postoperative week. In this series of patients, an oscillating bone saw, lifting type retractor, 2 blade spreader, cannula with a balloon, and right-angled aortic clamp among other items, were very useful for successfully performing various operations with MICS approaches and techniques. The associated results suggest that MICS with ministernotomy or minithoracotomy was feasible using special instruments and equipment and could be encouraged for adult patients with various cardiovascular diseases.

  10. Vitreoretinal surgical technique for transplanting retinal pigment epithelium in rabbit retina.

    PubMed

    Yamaguchi, K; Yamaguchi, K; Young, R W; Gaur, V P; Greven, C M; Slusher, M M; Turner, J E

    1992-01-01

    Transplantation of retinal pigment epithelial (RPE) cells has been proposed as a potential remedial procedure for previously untreatable retinal diseases. In this study, a vitreoretinal surgical technique was used to transplant pigmented RPE cells obtained from pigmented rabbits into the subretinal space of New Zealand White rabbits. At the time the animals were sacrificed, the retina was re-attached in all but 4 of the 24 experimental eyes. Histologically, by one week the transplanted RPE cells had formed a monolayer in patchy areas beneath the attached retina. By electron microscopy, RPE cells with prominent melanin granules were found attached to Bruch's membrane. Three weeks after transplantation, grafted RPE cells had formed apical microvilli and tight junctions with adjacent cells. The nucleus of the cells containing pigment had become oval, and their contact with Bruch's membrane appeared to be composed of bsal infoldings that were well formed. Our findings demonstrated the functional appearance of the transplanted RPE cells.

  11. Does the Implant Surgical Technique Affect the Primary and/or Secondary Stability of Dental Implants? A Systematic Review

    PubMed Central

    Shadid, Rola Muhammed; Sadaqah, Nasrin Rushdi; Othman, Sahar Abdo

    2014-01-01

    Background. A number of surgical techniques for implant site preparation have been advocated to enhance the implant of primary and secondary stability. However, there is insufficient scientific evidence to support the association between the surgical technique and implant stability. Purpose. This review aimed to investigate the influence of different surgical techniques including the undersized drilling, the osteotome, the piezosurgery, the flapless procedure, and the bone stimulation by low-level laser therapy on the primary and/or secondary stability of dental implants. Materials and methods. A search of PubMed, Cochrane Library, and grey literature was performed. The inclusion criteria comprised observational clinical studies and randomized controlled trials (RCTs) conducted in patients who received dental implants for rehabilitation, studies that evaluated the association between the surgical technique and the implant primary and/or secondary stability. The articles selected were carefully read and classified as low, moderate, and high methodological quality and data of interest were tabulated. Results. Eight clinical studies were included then they were classified as moderate or high methodological quality and control of bias. Conclusions. There is a weak evidence suggesting that any of previously mentioned surgical techniques could influence the primary and/or secondary implant stability. PMID:25126094

  12. Total anomalous pulmonary venous connection (surgical technique, early and late results).

    PubMed Central

    Di Eusanio, G; Sandrasagra, F A; Donnelly, R J; Hamilton, D I

    1978-01-01

    Between March 1970 and October 1977, 36 patients underwent correction of total anomalous pulmonary venous connection. The ages ranged from 5 days to 16 years; 27 (75%) were under 1 year and 19 were under 3 months of age at the time of surgery. The overall mortality was 33%. Supracardiac connection was the commonest type and was associated with the lowest hospital mortality (30%). The highest mortality occurred in the mixed and infracardiac types and was related in part to the presence of associated intracardiac anomalies. The use of hypothermia and circulatory arrest in infancy has resulted in a considerably lower hospital mortality compared with cases operated on under conventional cardiopulmonary bypass. The mortality in 23 infants (under 1 year of age) was 26% using circulatory arrest and was lowest when correction was performed within the first three months of life (18%). All four infants operated on with standard cardiopulmonary bypass died, whereas this technique was found to be safe in older children. The surgical technique using a left anterolateral thoractomy with a trans-sternal extension is described. This technique gives an excellent exposure for fashioning a long anastomosis and has been associated with a low incidence of postoperative pulmonary complications. There have been no late deaths and all survivors, who are in excellent condition up to seven years after correction, have a normal exercise tolerance. Images PMID:684663

  13. New surgical technique for the correction of congenital muscular torticollis (wry neck).

    PubMed

    Stassen, L F; Kerawala, C J

    2000-04-01

    Congenital muscular torticollis (wry neck) results from shortening of the sternocleidomastoid muscle and may lead to limitation of neck movement and craniofacial deformity. If conservative treatment is started early, with a regimen of passive stretching exercises and active strengthening of the contralateral muscle, about 95% of patients achieve an acceptable range of neck movement. The surgical management of patients who do not respond to physiotherapy remains controversial. Its aim is to provide a long-term, cosmetic restoration of neck mobility while minimizing the development of craniofacial deformity and upper cervical scoliosis; few previously advocated techniques achieve both these goals. We describe a technique that combines subperiosteal lengthening of the sternocleidomastoid muscle at its mastoid insertion, and division of lower fibrotic bands with minimal postoperative fibrosis. As the sternomastoid muscle is reattached lower down on the mastoid process, the lengthening of the muscle is stable, because the tendency to fibrosis and shortening is minimized. Comparison of the results with previous series shows that this technique provides immediate benefit and good long-term results.

  14. Using optimization models to demonstrate the need for structural changes in training programs for surgical medical residents.

    PubMed

    Turner, Jonathan; Kim, Kibaek; Mehrotra, Sanjay; DaRosa, Debra A; Daskin, Mark S; Rodriguez, Heron E

    2013-09-01

    The primary goal of a residency program is to prepare trainees for unsupervised care. Duty hour restrictions imposed throughout the prior decade require that residents work significantly fewer hours. Moreover, various stakeholders (e.g. the hospital, mentors, other residents, educators, and patients) require them to prioritize very different activities, often conflicting with their learning goals. Surgical residents' learning goals include providing continuity throughout a patient's pre-, peri-, and post-operative care as well as achieving sufficient surgical experience levels in various procedure types and participating in various formal educational activities, among other things. To complicate matters, senior residents often compete with other residents for surgical experience. This paper features experiments using an optimization model and a real dataset. The experiments test the viability of achieving the above goals at a major academic center using existing models of delivering medical education and training to surgical residents. It develops a detailed multi-objective, two-stage stochastic optimization model with anticipatory capabilities solved over a rolling time horizon. A novel feature of the models is the incorporation of learning curve theory in the objection function. Using a deterministic version of the model, we identify bounds on the achievement of learning goals under existing training paradigms. The computational results highlight the structural problems in the current surgical resident educational system. These results further corroborate earlier findings and suggest an educational system redesign is necessary for surgical medical residents. PMID:23519945

  15. Using optimization models to demonstrate the need for structural changes in training programs for surgical medical residents.

    PubMed

    Turner, Jonathan; Kim, Kibaek; Mehrotra, Sanjay; DaRosa, Debra A; Daskin, Mark S; Rodriguez, Heron E

    2013-09-01

    The primary goal of a residency program is to prepare trainees for unsupervised care. Duty hour restrictions imposed throughout the prior decade require that residents work significantly fewer hours. Moreover, various stakeholders (e.g. the hospital, mentors, other residents, educators, and patients) require them to prioritize very different activities, often conflicting with their learning goals. Surgical residents' learning goals include providing continuity throughout a patient's pre-, peri-, and post-operative care as well as achieving sufficient surgical experience levels in various procedure types and participating in various formal educational activities, among other things. To complicate matters, senior residents often compete with other residents for surgical experience. This paper features experiments using an optimization model and a real dataset. The experiments test the viability of achieving the above goals at a major academic center using existing models of delivering medical education and training to surgical residents. It develops a detailed multi-objective, two-stage stochastic optimization model with anticipatory capabilities solved over a rolling time horizon. A novel feature of the models is the incorporation of learning curve theory in the objection function. Using a deterministic version of the model, we identify bounds on the achievement of learning goals under existing training paradigms. The computational results highlight the structural problems in the current surgical resident educational system. These results further corroborate earlier findings and suggest an educational system redesign is necessary for surgical medical residents.

  16. Development of Multiobjective Optimization Techniques for Sonic Boom Minimization

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Aditi; Rajadas, John Narayan; Pagaldipti, Naryanan S.

    1996-01-01

    A discrete, semi-analytical sensitivity analysis procedure has been developed for calculating aerodynamic design sensitivities. The sensitivities of the flow variables and the grid coordinates are numerically calculated using direct differentiation of the respective discretized governing equations. The sensitivity analysis techniques are adapted within a parabolized Navier Stokes equations solver. Aerodynamic design sensitivities for high speed wing-body configurations are calculated using the semi-analytical sensitivity analysis procedures. Representative results obtained compare well with those obtained using the finite difference approach and establish the computational efficiency and accuracy of the semi-analytical procedures. Multidisciplinary design optimization procedures have been developed for aerospace applications namely, gas turbine blades and high speed wing-body configurations. In complex applications, the coupled optimization problems are decomposed into sublevels using multilevel decomposition techniques. In cases with multiple objective functions, formal multiobjective formulation such as the Kreisselmeier-Steinhauser function approach and the modified global criteria approach have been used. Nonlinear programming techniques for continuous design variables and a hybrid optimization technique, based on a simulated annealing algorithm, for discrete design variables have been used for solving the optimization problems. The optimization procedure for gas turbine blades improves the aerodynamic and heat transfer characteristics of the blades. The two-dimensional, blade-to-blade aerodynamic analysis is performed using a panel code. The blade heat transfer analysis is performed using an in-house developed finite element procedure. The optimization procedure yields blade shapes with significantly improved velocity and temperature distributions. The multidisciplinary design optimization procedures for high speed wing-body configurations simultaneously

  17. J-tube technique for double-j stent insertion during laparoscopic upper urinary tract surgical procedures.

    PubMed

    Kim, Hyung Suk; Lee, Byung Ki; Jung, Jin-Woo; Lee, Jung Keun; Byun, Seok-Soo; Lee, Sang Eun; Jeong, Chang Wook

    2014-11-01

    Double-J stent insertion has been generally performed during laparoscopic upper urinary tract (UUT) surgical procedures to prevent transient urinary tract obstruction and postoperative flank pain from ureteral edema and blood clots. Several restrictive conditions that make this procedure difficult and time consuming, however, include the coiled distal ends of the flexible Double-J stent and the limited bending angle of the laparoscopic instruments. To overcome these limitations, we devised a Double-J stent insertion method using the new J-tube technique. Between July 2011 and May 2013, Double-J stents were inserted using the J-tube technique in 33 patients who underwent a laparoscopic UUT surgical procedure by a single surgeon. The mean stent placement time was 4.8±2.7 minutes, and there were no intraoperative complications. In conclusion, the J-tube technique is a safe and time-saving method for Double-J stent insertion during laparoscopic surgical procedures.

  18. Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

    PubMed Central

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th.; Mauerer, Andreas; Hennig, Friedrich F.; Buder, Thomas

    2015-01-01

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture’s morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology. PMID

  19. Optimization of CT colonography technique: a practical guide.

    PubMed

    Tolan, D J M; Armstrong, E M; Burling, D; Taylor, S A

    2007-09-01

    In this article we provide practical advice for optimizing computed tomography colonography (CTC) technique to help ensure that reproducible, high-quality examinations are achieved. Relevant literature is reviewed and specific attention is paid to patient information, bowel cleansing, insufflation, anti-spasmodics, patient positioning, CT technique, post-procedure care and complications, as well as practical problem-solving advice. There are many different approaches to performing CTC; our aim is to not to provide a comprehensive review of the literature, but rather to present a practical and robust protocol, providing guidance, particularly to those clinicians with little prior experience of the technique.

  20. RADIOGRAPHIC ABNORMALITIES OF THE TALUS IN PATIENTS WITH CLUBFOOT AFTER SURGICAL RELEASE USING THE MCKAY TECHNIQUE

    PubMed Central

    Pinto, José Antonio; Hernandes, Andréa Canizares; Buchaim, Thais Paula; Blumetti, Francesco Camara; Chertman, Carla; Yamane, Patrícia Corey; da Rocha Corrêa Fernandes, Artur

    2015-01-01

    Objective: To analyze morphological abnormalities of the talus in patients with clubfoot after surgical treatment using the McKay technique. Method: Lateral standing-position radiographs of the feet of 14 patients with unilateral clubfoot who underwent treatment by means of the doubleincision McKay technique were retrospectively analyzed. All the patients were operated by the same surgeon, with an average of 6.53 years between surgery and the radiograph. We compared the radiographic characteristics of the talus between the operated and the contralateral foot. We assessed the presence of deformity of the talar dome and head (sphericity evaluation); the talar length and height; the percentage and degree of navicular subluxation; abnormalities of the Gissane angle; and the trabecular bone pattern. Results: Abnormalities of the talar head occurred in 92.8% of the patients; of the talar dome in 92.8%; and of the trabecular pattern in 100%. The talar length ratio between the operated and the contralateral foot ranged from 0.61 to 0.88 (mean 0.79; SD = 0.09), while the height ratio ranged from 0.57 to 0.98 (mean 0.82; SD = 0.12). The Gissane angle was greater in all of the operated feet, and all of them also showed navicular subluxation, at a rate ranging from 6.43 to 59.75% (mean 26.34%; SD = 16.66%). Conclusion: Talar abnormalities occurred in 100% of the feet treated using the McKay technique. It was shown that establishing radiographic parameters to describe and quantify these deformities was feasible, through simple and easy-to-perform techniques. PMID:27047821

  1. Efficiency of Various Cerebral Protection Techniques Used during the Surgical Treatment of Chronic Pulmonary Thromboembolism

    PubMed Central

    Kamenskaya, Oksana Vasilyevna; Cherniavsky, Alexander Mikhailovich; Klinkova, Asya Stanislavovna; Cherniavsky, Mikhail Alexandrovich; Meshkov, Ivan Olegovich; Lomivorotov, Vladimir Vladimirovich; Kornilov, Igor Anatolyevich; Karaskov, Alexander Mikhailovich

    2015-01-01

    Abstract: Circulatory arrest during pulmonary thromboendarterectomy (PTE) for chronic pulmonary embolism leads to an increased risk of cerebral ischemia and neurological complications. This study aimed to assess the efficacy of various cerebral protection techniques used during the surgical treatment of chronic pulmonary thromboembolism. We prospectively studied 61 patients with chronic pulmonary thromboembolism who underwent PTE. We compared the dynamics of cerebral oxygen saturation (rSO2, %) during the surgical treatment and analyzed neurological complications during the early postoperative period in two groups of patients: 30 patients who underwent surgery under conditions of moderate hypothermia (23°C–24°C) combined with antegrade unilateral cerebral perfusion (ACP group) and 31 patients who underwent thromboendarterectomy under deep hypothermic circulatory arrest (18°C, DHCA group) combined with craniocerebral hypothermia. In the ACP group, regional rSO2 decreased by less than 20% from baseline during the course of PTE. In the DHCA group, a more profound reduction of cerebral oxygen supply (by >30% from baseline) was recorded compared with the ACP group (p < .05). During the early postoperative period, 29% of patients in the DHCA group exhibited neurological complications, compared with only 7% of patients from the ACP group. The results of logistic regression analysis indicated that the risk of progressive neurological deficit depended on the duration of the intraoperative period when the absolute values of regional rSO2 were <40%. The method with the best adjustment to human physiology in patients with chronic pulmonary thromboembolism was antegrade cerebral perfusion. This method provides a smaller decrease in cerebral oxygen supply during thromboendarterectomy and significantly reduces the risk of ischemia and neurological complications in the early postoperative period. PMID:26405357

  2. Gluteal tendon repair augmented with a synthetic ligament: surgical technique and a case series.

    PubMed

    Bucher, Thomas A; Darcy, Peter; Ebert, Jay R; Smith, Anne; Janes, Greg

    2014-01-01

    We describe an augmented surgical repair technique for gluteus minimus and medius tears, along with a supportive case series. A consecutive series of 22 patients presenting with clinical and radiological findings consistent with hip abductor tears, who had undergone failed prior conservative treatments, were prospectively recruited. Patients underwent open bursectomy, Y-iliotibial release, debridement of the diseased tendon, decortication of the trochanteric foot-plate and reattachment augmented with a LARS ligament through a trans-osseous tunnel, together with suture anchors. All patients were assessed pre- and postoperatively to 12 months with the Oxford Hip Score (OHS), the Short-Form Health Survey (SF-36) and a Visual Analogue Pain Scale (VAS), while a satisfaction scale was employed at 12 months. A statistically significant improvement (p<0.05) was observed for all patient reported outcome measures, while all patients were at least 'satisfied' with the procedure at 12 months. One patient reported some lateral hip discomfort at 10 months, and removal of the LARS interference screw provided immediate relief. One patient had a urological catheter-related complication. With no other complications and no clinical failures of the repair, we believe the technique to be safe and reliable, whilst reducing the incidence of re-tears as reported in the existing literature. PMID:24186680

  3. Complete mesocolic excision and central vascular ligation for colon cancer: Principle, anatomy, surgical technique, and outcomes.

    PubMed

    Kim, Nam Kyu; Kim, Young Wan; Han, Yoon Dae; Cho, Min Soo; Hur, Hyuk; Min, Byung Soh; Lee, Kang Young

    2016-09-01

    Classic colon cancer surgery refers to a wide resection of the tumor-bearing segment and the lymphatics draining along the named artery. The concept of TME has been applied to colon cancer and complete mesocolic excision (CME) in conjuction with central vascular ligation (CVL) has been introduced as the surgical treatment for colon cancer. Here, we discuss appropriate CME procedure with regard to the oncologic backgrounds, essential components, applied anatomy, laparoscopic technique, short-term, and oncologic outcomes. The introduction of CME has improved oncologic outcomes greatly in patients with colon cancer. The improved outcomes with CME can be attributed to underlying sound oncologic principles such as dissection through the proper plane of mesocolic excision, central vascular ligation, and sufficient length of proximal and distal margins. Thereby, CME technique can achieve en bloc removal of the diseased lesion with the increased amount of the colonic mesentery even though the length of for both bowel and mesentery resection remains a matter of debate. CME is a technically demanding operation thus, comprehensive understanding of the applied vascular anatomy is essential for successful CME. Favorable outcomes of open CME have been replicated with a laparoscopic approach. In future perspective, incorporating a structured education program on minimally invasive (laparoscopy or robot) CME would be beneficial. PMID:27566031

  4. A method to objectively optimize coral bleaching prediction techniques

    NASA Astrophysics Data System (ADS)

    van Hooidonk, R. J.; Huber, M.

    2007-12-01

    Thermally induced coral bleaching is a global threat to coral reef health. Methodologies, e.g. the Degree Heating Week technique, have been developed to predict bleaching induced by thermal stress by utilizing remotely sensed sea surface temperature (SST) observations. These techniques can be used as a management tool for Marine Protected Areas (MPA). Predictions are valuable to decision makers and stakeholders on weekly to monthly time scales and can be employed to build public awareness and support for mitigation. The bleaching problem is only expected to worsen because global warming poses a major threat to coral reef health. Indeed, predictive bleaching methods combined with climate model output have been used to forecast the global demise of coral reef ecosystems within coming decades due to climate change. Accuracy of these predictive techniques has not been quantitatively characterized despite the critical role they play. Assessments have typically been limited, qualitative or anecdotal, or more frequently they are simply unpublished. Quantitative accuracy assessment, using well established methods and skill scores often used in meteorology and medical sciences, will enable objective optimization of existing predictive techniques. To accomplish this, we will use existing remotely sensed data sets of sea surface temperature (AVHRR and TMI), and predictive values from techniques such as the Degree Heating Week method. We will compare these predictive values with observations of coral reef health and calculate applicable skill scores (Peirce Skill Score, Hit Rate and False Alarm Rate). We will (a) quantitatively evaluate the accuracy of existing coral reef bleaching predictive methods against state-of- the-art reef health databases, and (b) present a technique that will objectively optimize the predictive method for any given location. We will illustrate this optimization technique for reefs located in Puerto Rico and the US Virgin Islands.

  5. Evaluation of a minimally invasive surgical fixation technique for young children with the Concerto Pin cochlear implant system.

    PubMed

    Schnabl, Johannes; Wolf-Magele, Astrid; Pok, Stefan Marcel; Url, Christoph; Zorowka, Patrick; Sprinzl, Georg

    2015-08-01

    In 2011, Med-El (Innsbruck, Austria) introduced a new cochlear implant system, designed to require a minimally invasive surgical technique and allow greater positional flexibility for its fixation on the skull. The Concerto Pin implant system is a good option for patients with thinner bone, such as children and elderly. The aim of this study was to investigate the implant’s stability in children using our minimally invasive surgical technique. This was a prospective, longitudinal study with a single-subject, repeated-examination design. Six children, implanted with a Concerto Pin using our minimally invasive surgical technique between October 2011 and September 2012, were assessed 1, 3 and 6 months after surgery. In each case, the implant remained in a stable position and no adverse events or problems with healing were observed at any time during the investigation. The minimally invasive technique and the method of implant fixation that bypass drilling a deep implant bed constitute a good option for patients with thinner bone, such as children. This clinical study shows the safety and stability of the Concerto Pin implant system using a minimally invasive surgical technique.

  6. An Image Morphing Technique Based on Optimal Mass Preserving Mapping

    PubMed Central

    Zhu, Lei; Yang, Yan; Haker, Steven; Tannenbaum, Allen

    2013-01-01

    Image morphing, or image interpolation in the time domain, deals with the metamorphosis of one image into another. In this paper, a new class of image morphing algorithms is proposed based on the theory of optimal mass transport. The L2 mass moving energy functional is modified by adding an intensity penalizing term, in order to reduce the undesired double exposure effect. It is an intensity-based approach and, thus, is parameter free. The optimal warping function is computed using an iterative gradient descent approach. This proposed morphing method is also extended to doubly connected domains using a harmonic parameterization technique, along with finite-element methods. PMID:17547128

  7. An image morphing technique based on optimal mass preserving mapping.

    PubMed

    Zhu, Lei; Yang, Yan; Haker, Steven; Tannenbaum, Allen

    2007-06-01

    Image morphing, or image interpolation in the time domain, deals with the metamorphosis of one image into another. In this paper, a new class of image morphing algorithms is proposed based on the theory of optimal mass transport. The L(2) mass moving energy functional is modified by adding an intensity penalizing term, in order to reduce the undesired double exposure effect. It is an intensity-based approach and, thus, is parameter free. The optimal warping function is computed using an iterative gradient descent approach. This proposed morphing method is also extended to doubly connected domains using a harmonic parameterization technique, along with finite-element methods. PMID:17547128

  8. Transposition of Great Arteries with Intramural Coronary Artery: Experience with a Modified Surgical Technique

    PubMed Central

    Mishra, Amit; Jain, Anil; Hinduja, Manish; Wadhawa, Vivek; Patel, Ramesh; Vaidhya, Nikunj; Rodricks, Dayesh; Patel, Hardik

    2016-01-01

    Objective: Transposition of the great arteries is a common congenital heart disease. Arterial switch is the gold standard operation for this complex heart disease. Arterial switch operation in the presence of intramural coronary artery is surgically the most demanding even for the most experienced hands. We are presenting our experience with a modified technique for intramural coronary arteries in arterial switch operation. Methods: This prospective study involves 450 patients undergoing arterial switch operation at our institute from April 2006 to December 2013 (7.6 years). Eighteen patients underwent arterial switch operation with intramural coronary artery. The coronary patterns and technique used are detailed in the text. Results: The overall mortality found in the subgroup of 18 patients having intramural coronary artery was 16% (n=3). Our first patient had an accidental injury to the left coronary artery and died in the operating room. A seven-day old newborn died from intractable ventricular arrhythmia fifteen hours after surgery. Another patient who had multiple ventricular septal defects with type B arch interruption died from residual apical ventricular septal defect and sepsis on the eleventh postoperative day. The remainder of the patients are doing well, showing a median follow-up duration of 1235.34±815.26 days (range 369 - 2730). Conclusion: Transposition of the great arteries with intramural coronary artery is demanding in a subset of patients undergoing arterial switch operation. We believe our technique of coronary button dissection in the presence of intramural coronary arteries using coronary shunt is simple and can be a good addition to the surgeons' armamentarium. PMID:27074270

  9. Diabetic arthropathy of the first metatarsal cuneiform joint. Introduction of a new surgical fusion technique.

    PubMed

    Cohn, B T; Brahms, M A

    1987-07-01

    This paper describes the surgical treatment of advanced arthropathy of the first metatarsal cuneiform joint in the diabetic patient. A new surgical procedure is described as performed on a 59-year-old black diabetic woman with advanced arthropathy of the first metatarsal cuneiform joint. A brief review of diabetic arthropathy is presented, with special emphasis on the first metatarsal cuneiform joint involvement. The authors believe that with early diagnosis and surgical fusion, the process of rapid tarsal disintegration can be prevented.

  10. Model reduction using new optimal Routh approximant technique

    NASA Technical Reports Server (NTRS)

    Hwang, Chyi; Guo, Tong-Yi; Sheih, Leang-San

    1992-01-01

    An optimal Routh approximant of a single-input single-output dynamic system is a reduced-order transfer function of which the denominator is obtained by the Routh approximation method while the numerator is determined by minimizing a time-response integral-squared-error (ISE) criterion. In this paper, a new elegant approach is presented for obtaining the optimal Routh approximants for linear time-invariant continuous-time systems. The approach is based on the Routh canonical expansion, which is a finite-term orthogonal series of rational basis functions, and minimization of the ISE criterion. A procedure for combining the above approach with the bilinear transformation is also presented in order to obtain the optimal bilinear Routh approximants of linear time-invariant discrete-time systems. The proposed technique is simple in formulation and is amenable to practical implementation.

  11. [Clinical experience with a C-section surgical technique in patients with morbid obesity: a case series].

    PubMed

    Hernández Carrazco, Mayra Elena; Rodríguez Torres, Alejandra; Ortiz Pineda, Omar; Rodríguez Torres, Juan; Casas Patiño, Donovan

    2014-07-04

    Obesity is a public health challenge that has crossed into the area of reproductive health. An obese pregnant woman has multiple complications before, during, and after pregnancy. Likewise, cesarean section is more difficult and has slower recovery times in this group of patients. This paper proposes a surgical technique adapted to the morbidly obese pregnant patient that aims to reduce cesarean section complications.

  12. “Two-step” technique with OsiriX™ to evaluate feasibility of C2 pedicle for surgical fixation

    PubMed Central

    Marques, Luis Miguel Sousa; d’Almeida, Gonçalo Neto; Cabral, José

    2016-01-01

    Background: Surgical treatment of craniovertebral junction pathology has evolved considerably in recent decades with the implementation of short atlanto-axial fixation techniques, notwhithstanding increasing neurovascular risks. Also, there is strong evidence that fixation of C2 anatomical pedicle has the best biomechanical profile of the entire cervical spine. However, it is often difficult and misleading, to evaluate anatomical bony and vascular anomalies using the three orthogonal planes (axial, coronal, and sagittal) of CT. Objectives: The authors describe an innovative and simple technique to evaluate the feasibility of C2 pedicle for surgical screw fixation using preoperative planning with the free DICOM (Digital Imaging and Communications in Medicine) software OsiriX™. Materials and Methods: The authors report the applicatin of this novel technique in 5 cases (3 traumatic, 1 Os Odontoideum, and 1 complex congenital malformation) collected from our general case series of the Department in the last 5 years. Results: In this proof of concept study, the pre-operative analysis with the two-step tecnique was detrimental for choosing the surgical tecnique. Detailed post-operative analysis confirmed correct position of C2 screws without cortical breach. There were no complications or mortality reported. Conclusion: This two-step technique is an easy and reliable way to determine the feasibility of C2 pedicle for surgical fixation. The detailed tridimensional radiological preoperative evaluation of craniovertebral junction anatomy is critical to the sucess and safety of this surgeries, and can avoid, to certain degree, expensive intra-operative tridimensional imaging facilities. PMID:27217652

  13. Accelerating orthodontic tooth movement: A new, minimally-invasive corticotomy technique using a 3D-printed surgical template

    PubMed Central

    Giansanti, Matteo

    2016-01-01

    Background A reduction in orthodontic treatment time can be attained using corticotomies. The aggressive nature of corticotomy due to the elevation of muco-periosteal flaps and to the duration of the surgery raised reluctance for its employ among patients and dental community. This study aims to provide detailed information on the design and manufacture of a 3D-printed CAD-CAM (computer-aided design and computer-aided manufacturing) surgical guide which can aid the clinician in achieving a minimally-invasive, flapless corticotomy. Material and Methods An impression of dental arches was created; the models were digitally-acquired using a 3D scanner and saved as STereoLithography ( STL ) files. The patient underwent cone beam computed tomography (CBCT): images of jaws and teeth were transformed into 3D models and saved as an STL file. An acrylic template with the design of a surgical guide was manufactured and scanned. The STLs of jaws, scanned casts, and acrylic templates were matched. 3D modeling software allowed the view of the 3D models from different perspectives and planes with perfect rendering. The 3D model of the acrylic template was transformed into a surgical guide with slots designed to guide, at first, a scalpel blade and then a piezoelectric cutting insert. The 3D STL model of the surgical guide was printed. Results This procedure allowed the manufacturing of a 3D-printed CAD/CAM surgical guide, which overcomes the disadvantages of the corticotomy, removing the need for flap elevation. No discomfort, early surgical complications or unexpected events were observed. Conclusions The effectiveness of this minimally-invasive surgical technique can offer the clinician a valid alternative to other methods currently in use. Key words:Corticotomy, orthodontics, CAD/CAM, minimally invasive, surgical template, 3D printer. PMID:27031067

  14. Vascular Z-shaped ligation technique in surgical treatment of haemorrhoid

    PubMed Central

    Gemici, Kazım; Okuş, Ahmet; Ay, Serden

    2015-01-01

    AIM: To present the effectiveness of minimal invasive vascular zet ligation in the surgical treatment of haemorrhoidal disease (HD). METHODS: Among 138 patients with 2nd-4th grade internal HD having several complaints and operated at our hospital between 2003-2013; 116 patients who regularly attended 1-year control were included in the study. Operation times, postoperative early period pain, satisfaction score, complications and relapse details were obtained from computer records retrospectively. Visual Analogous Scale (VAS) scores were used for patient satisfaction on the 3rd, 7th and 21st days. Technique; fixed suture which is constituted by the first leg of the Z-shaped suture (to pass by the mucosa and muscular layer) was put in the pile root in order to ensure vascular ligation and fixation. The second leg of the Z-shaped suture is constituted by mobile suture and it passes by the pile mucosa and submucosa which prolapses 5-10 mm below the first suture. RESULTS: Seventy-five of the patients (65%) were male, 41 of them (35%) were female and their age average was 41. The mean operation time was 12 ± 4.8 min. VAS/satisfaction score was found as 2.2/4.3, 1.8/4.0, 1.2/4.4 respectively on the 3rd, 7th, and 21st days. Four of the patient (3.5%) had relapse. CONCLUSION: This technique is an easily applicable, cost efficient way of operation which increases patient satisfaction. PMID:25625005

  15. Optimization of backward giant circle technique on the asymmetric bars.

    PubMed

    Hiley, Michael J; Yeadon, Maurice R

    2007-11-01

    The release window for a given dismount from the asymmetric bars is the period of time within which release results in a successful dismount. Larger release windows are likely to be associated with more consistent performance because they allow a greater margin for error in timing the release. A computer simulation model was used to investigate optimum technique for maximizing release windows in asymmetric bars dismounts. The model comprised four rigid segments with the elastic properties of the gymnast and bar modeled using damped linear springs. Model parameters were optimized to obtain a close match between simulated and actual performances of three gymnasts in terms of rotation angle (1.5 degrees ), bar displacement (0.014 m), and release velocities (<1%). Three optimizations to maximize the release window were carried out for each gymnast involving no perturbations, 10-ms perturbations, and 20-ms perturbations in the timing of the shoulder and hip joint movements preceding release. It was found that the optimizations robust to 20-ms perturbations produced release windows similar to those of the actual performances whereas the windows for the unperturbed optimizations were up to twice as large. It is concluded that robustness considerations must be included in optimization studies in order to obtain realistic results and that elite performances are likely to be robust to timing perturbations of the order of 20 ms. PMID:18089928

  16. Pilot study: evaluation of the use of the convergent interview technique in understanding the perception of surgical design and simulation

    PubMed Central

    2013-01-01

    Background It is important to understand the perceived value of surgical design and simulation (SDS) amongst surgeons, as this will influence its implementation in clinical settings. The purpose of the present study was to examine the application of the convergent interview technique in the field of surgical design and simulation and evaluate whether the technique would uncover new perceptions of virtual surgical planning (VSP) and medical models not discovered by other qualitative case-based techniques. Methods Five surgeons were asked to participate in the study. Each participant was interviewed following the convergent interview technique. After each interview, the interviewer interpreted the information by seeking agreements and disagreements among the interviewees in order to understand the key concepts in the field of SDS. Results Fifteen important issues were extracted from the convergent interviews. Conclusion In general, the convergent interview was an effective technique in collecting information about the perception of clinicians. The study identified three areas where the technique could be improved upon for future studies in the SDS field. PMID:23782771

  17. Enhanced regeneration of corneal tissue via a bioengineered collagen construct implanted by a nondisruptive surgical technique.

    PubMed

    Koulikovska, Marina; Rafat, Mehrdad; Petrovski, Goran; Veréb, Zoltán; Akhtar, Saeed; Fagerholm, Per; Lagali, Neil

    2015-03-01

    Severe shortage of donor corneas for transplantation, particularly in developing countries, has prompted the advancement of bioengineered tissue alternatives. Bioengineered corneas that can withstand transplantation while maintaining transparency and compatibility with host cells, and that are additionally amenable to standardized low-cost mass production are sought. In this study, a bioengineered porcine construct (BPC) was developed to function as a biodegradable scaffold to promote corneal stromal regeneration by host cells. Using high-purity medical-grade type I collagen, high 18% collagen content and optimized EDC-NHS cross-linker ratio, BPCs were fabricated into hydrogel corneal implants with over 90% transparency and four-fold increase in strength and stiffness compared with previous versions. Remarkably, optical transparency was achieved despite the absence of collagen fibril organization at the nanoscale. In vitro testing indicated that BPC supported confluent human epithelial and stromal-derived mesenchymal stem cell populations. With a novel femtosecond laser-assisted corneal surgical model in rabbits, cell-free BPCs were implanted in vivo in the corneal stroma of 10 rabbits over an 8-week period. In vivo, transparency of implanted corneas was maintained throughout the postoperative period, while healing occurred rapidly without inflammation and without the use of postoperative steroids. BPC implants had a 100% retention rate at 8 weeks, when host stromal cells began to migrate into implants. Direct histochemical evidence of stromal tissue regeneration was observed by means of migrated host cells producing new collagen from within the implants. This study indicates that a cost-effective BPC extracellular matrix equivalent can incorporate cells passively to initiate regenerative healing of the corneal stroma, and is compatible with human stem or organ-specific cells for future therapeutic applications as a stromal replacement for treating blinding

  18. Far lateral microdiscectomy: a minimally-invasive surgical technique for the treatment of far lateral lumbar disc herniation

    PubMed Central

    Phan, Kevin; Dunn, Alexander E.; Rao, Prashanth J.

    2016-01-01

    Lumbar disc herniation arises when the annulus fibrosus of the vertebral disc fails, thus allowing displacement of the nucleus pulposus and other tissue. The term far lateral is used variably in the literature and usually refers to an extraforaminal displacement in the peridiscal zone peripheral to the sagittal plane of the most lateral part of the pedicle at the same level. Non-surgical treatments of far lateral disc herniation include physical therapy, anti-inflammatory medication, and corticosteroid injections. Where these conservative measures fail, surgical intervention may be required. Several surgical techniques for the treatment of far lateral herniations have been investigated, including total or medial facetectomy, laminectomy, hemilaminectomy, approaches through the pars interarticularis, and lateral approaches between the transverse processes via the intertransverse muscle and ligament. We present our far lateral microdiscectomy technique which involves accessing the nerve root lateral to the foramen through a small paramedian incision and use of an operating microscope. Far lateral microdiscectomy offers the prospect of better long-term results than other surgical techniques because of less extensive muscle dissection and preservation of the integrity of the facet joint.

  19. Far lateral microdiscectomy: a minimally-invasive surgical technique for the treatment of far lateral lumbar disc herniation.

    PubMed

    Phan, Kevin; Dunn, Alexander E; Rao, Prashanth J; Mobbs, Ralph J

    2016-03-01

    Lumbar disc herniation arises when the annulus fibrosus of the vertebral disc fails, thus allowing displacement of the nucleus pulposus and other tissue. The term far lateral is used variably in the literature and usually refers to an extraforaminal displacement in the peridiscal zone peripheral to the sagittal plane of the most lateral part of the pedicle at the same level. Non-surgical treatments of far lateral disc herniation include physical therapy, anti-inflammatory medication, and corticosteroid injections. Where these conservative measures fail, surgical intervention may be required. Several surgical techniques for the treatment of far lateral herniations have been investigated, including total or medial facetectomy, laminectomy, hemilaminectomy, approaches through the pars interarticularis, and lateral approaches between the transverse processes via the intertransverse muscle and ligament. We present our far lateral microdiscectomy technique which involves accessing the nerve root lateral to the foramen through a small paramedian incision and use of an operating microscope. Far lateral microdiscectomy offers the prospect of better long-term results than other surgical techniques because of less extensive muscle dissection and preservation of the integrity of the facet joint. PMID:27683697

  20. [Medico-social and administrative aspects of optimization of thoracoabdominal aortic aneurism surgical treatment].

    PubMed

    Belov, Iu V; Komarov, R N

    2008-01-01

    Improvement of diagnostics, availability and quality of surgical help for patients with thoracoabdominal aneurisms is necessary. Cardiosurgical hospitals should be supplied with modern equipment, new technologies should be wider introduced to practice. Establishing departments of aortic surgery with the concentration of patients in the single center together with the risin the level of surgical skills are crucial. PMID:18577964

  1. [Medico-social and administrative aspects of optimization of thoracoabdominal aortic aneurism surgical treatment].

    PubMed

    Belov, Iu V; Komarov, R N

    2008-01-01

    Improvement of diagnostics, availability and quality of surgical help for patients with thoracoabdominal aneurisms is necessary. Cardiosurgical hospitals should be supplied with modern equipment, new technologies should be wider introduced to practice. Establishing departments of aortic surgery with the concentration of patients in the single center together with the risin the level of surgical skills are crucial.

  2. Pulley Reconstruction As Part of the Surgical Treatment for de Quervain Disease: Surgical Technique with Medium-Term Results

    PubMed Central

    van der Wijk, Jacobien; Goubau, Jean F.; Mermuys, Koen; van Hoonacker, Petrus; Vanmierlo, Bert; Kerckhove, Diederick; Berghs, Bart

    2015-01-01

    Background Simple decompression of the first extensor compartment is commonly used for treating de Quervain disease, with the possible complication of subluxation of the tendons of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) over the radial styloid. To prevent this painful subluxation of the tendons, several methods of reconstructing the pulley have been proposed. Questions/Purposes The purpose of our study was to evaluate a new technique for reconstructing the first extensor compartment following a release for de Quervain disease. Patients and Methods A retrospective study (mean length 40.4 months) was performed in 45 patients. The outcome assessment involved two different questionnaires and ultrasound evaluation of any tendon subluxation. Results None of the patients required reoperation for tendon instability or incomplete decompression of the first extensor compartment. Two patients experienced clicking around the radial styloid after surgery. This was not related to the amount of volar migration of the tendons. Conclusions We believe the reconstruction proposed here is an effective method of preventing painful subluxation of the APL and EPB following a release of the first extensor compartment. PMID:26261747

  3. The Role of Minimally Invasive Surgical Techniques in the Management of Large-gland Benign Prostatic Hypertrophy.

    PubMed

    Sivarajan, Ganesh; Borofsky, Michael S; Shah, Ojas; Lingeman, James E; Lepor, Herbert

    2015-01-01

    Lower urinary tract symptoms (LUTS) secondary to benign prostatic hypertrophy (BPH) are among the most common medical issues for aging men. Population-based studies suggest that 13.8% of men in their 40s and more than 40% of men over age 60 have BPH. When LUTS are refractory to medical therapy and bothersome enough to warrant surgical intervention, transurethral resection of the prostate and open simple prostatectomy have been the historical reference-standard procedures for decades. Both procedures are highly effective and offer durable improvements in urinary functional outcomes. However, they also have the potential for considerable perioperative complications and morbidity. In an effort to limit surgical morbidity, a variety of minimally invasive surgical techniques to treat BPH have been introduced. Herein we present a comprehensive, evidence-based review of the efficacy and safety profile of modern minimally invasive treatments for large-gland BPH.

  4. Techniques for developing reliability-oriented optimal microgrid architectures

    NASA Astrophysics Data System (ADS)

    Patra, Shashi B.

    2007-12-01

    Alternative generation technologies such as fuel cells, micro-turbines, solar etc. have been the focus of active research in the past decade. These energy sources are small and modular. Because of these advantages, these sources can be deployed effectively at or near locations where they are actually needed, i.e. in the distribution network. This is in contrast to the traditional electricity generation which has been "centralized" in nature. The new technologies can be deployed in a "distributed" manner. Therefore, they are also known as Distributed Energy Resources (DER). It is expected that the use of DER, will grow significantly in the future. Hence, it is prudent to interconnect the energy resources in a meshed or grid-like structure, so as to exploit the reliability and economic benefits of distributed deployment. These grids, which are smaller in scale but similar to the electric transmission grid, are known as "microgrids". This dissertation presents rational methods of building microgrids optimized for cost and subject to system-wide and locational reliability guarantees. The first method is based on dynamic programming and consists of determining the optimal interconnection between microsources and load points, given their locations and the rights of way for possible interconnections. The second method is based on particle swarm optimization. This dissertation describes the formulation of the optimization problem and the solution methods. The applicability of the techniques is demonstrated in two possible situations---design of a microgrid from scratch and expansion of an existing distribution system.

  5. Demonstration of optimization techniques for groundwater plume remediation

    SciTech Connect

    Finsterle, Stefan

    2000-09-01

    We examined the potential use of standard optimization algorithms for the solution of aquifer remediation problems. Costs for the removal of dissolved or free-phase contaminants depend on aquifer properties, the chosen remediation technology, and operational parameters (such as number of wells drilled and pumping rates). A cost function must be formulated that may include actual costs and hypothetical penalty costs for incomplete cleanup; the total cost function is therefore a measure of the overall effectiveness and efficiency of the proposed remediation scenario. In this study, the cost function is minimized by automatically adjusting certain operational parameters. The impact of these operational parameters on remediation is evaluated using a state-of-the-art three-phase, three-component flow and transport simulator, which is linked to nonlinear optimization routines. The report demonstrates that methods developed for automatic model calibration are capable of minimizing arbitrary cost functions. Two illustrative examples are presented. While hypothetical, these examples demonstrate that remediation costs can be substantially lowered by combining simulation and optimization techniques. The second example on co-injection of air and steam also make evident the need for coupling optimization routines with an accurate state-of-the-art process simulator. Simplified models are likely to miss significant system behaviors such as increased downward mobilization due to recondensation of contaminants during steam flooding, which can be partly suppressed by the co-injection of air.

  6. Automated parameterization of intermolecular pair potentials using global optimization techniques

    NASA Astrophysics Data System (ADS)

    Krämer, Andreas; Hülsmann, Marco; Köddermann, Thorsten; Reith, Dirk

    2014-12-01

    In this work, different global optimization techniques are assessed for the automated development of molecular force fields, as used in molecular dynamics and Monte Carlo simulations. The quest of finding suitable force field parameters is treated as a mathematical minimization problem. Intricate problem characteristics such as extremely costly and even abortive simulations, noisy simulation results, and especially multiple local minima naturally lead to the use of sophisticated global optimization algorithms. Five diverse algorithms (pure random search, recursive random search, CMA-ES, differential evolution, and taboo search) are compared to our own tailor-made solution named CoSMoS. CoSMoS is an automated workflow. It models the parameters' influence on the simulation observables to detect a globally optimal set of parameters. It is shown how and why this approach is superior to other algorithms. Applied to suitable test functions and simulations for phosgene, CoSMoS effectively reduces the number of required simulations and real time for the optimization task.

  7. Optimization Techniques for 3D Graphics Deployment on Mobile Devices

    NASA Astrophysics Data System (ADS)

    Koskela, Timo; Vatjus-Anttila, Jarkko

    2015-03-01

    3D Internet technologies are becoming essential enablers in many application areas including games, education, collaboration, navigation and social networking. The use of 3D Internet applications with mobile devices provides location-independent access and richer use context, but also performance issues. Therefore, one of the important challenges facing 3D Internet applications is the deployment of 3D graphics on mobile devices. In this article, we present an extensive survey on optimization techniques for 3D graphics deployment on mobile devices and qualitatively analyze the applicability of each technique from the standpoints of visual quality, performance and energy consumption. The analysis focuses on optimization techniques related to data-driven 3D graphics deployment, because it supports off-line use, multi-user interaction, user-created 3D graphics and creation of arbitrary 3D graphics. The outcome of the analysis facilitates the development and deployment of 3D Internet applications on mobile devices and provides guidelines for future research.

  8. Prospective study of percutaneous tracheostomy: Role of bronchoscopy and surgical technique

    PubMed Central

    Laisaar, Tanel; Jakobson, Eero; Sarana, Bruno; Sarapuu, Silver; Vahtramäe, Jüri; Raag, Mait

    2016-01-01

    Objective: Percutaneous tracheostomy is a common procedure but varies considerably in approach. The aim of our study was to evaluate the need for intraoperative bronchoscopy and to compare various surgical techniques. Methods: During 1 year all percutaneous tracheostomies in three intensive care units were prospectively documented according to a unified protocol. In one unit, bronchoscopy was used routinely and in others only during the study. Results: A total of 111 subjects (77 males) with median age 64 (range, 18–86) years and body mass index 25.4 (range, 15.9–50.7) were included. In unit A, tracheal wall was directly exposed; in unit B, limited dissection to enable tracheal palpation was made. In both units, bronchoscopy was used to check the location of an already inserted guiding needle; needle position required correction in 8% and 12% of cases, respectively. In unit C, in tracheostomies without pretracheal tissue dissection, bronchoscopy was used to guide needle insertion; needle position required correction in 66% of cases. Median duration of operations performed by thoracic surgeons and residents was 10 (range, 3–37) min and by intensive care doctors and residents was 16.5 (range, 3–63) min (p < 0.001). Time from the beginning of preparations for tracheostomy until the end of the whole procedure was median 32 min for bedside tracheostomies and 64 min for operations in the operating theatre (p < 0.001). Conclusion: Limited pretracheal tissue dissection enabled proper guiding needle insertion and bronchoscopy was rarely needed. Percutaneous tracheostomies performed by thoracic surgeons took less time, and duration of the whole procedure was remarkably shorter when performed at bedside. PMID:27708779

  9. Machine learning techniques for energy optimization in mobile embedded systems

    NASA Astrophysics Data System (ADS)

    Donohoo, Brad Kyoshi

    Mobile smartphones and other portable battery operated embedded systems (PDAs, tablets) are pervasive computing devices that have emerged in recent years as essential instruments for communication, business, and social interactions. While performance, capabilities, and design are all important considerations when purchasing a mobile device, a long battery lifetime is one of the most desirable attributes. Battery technology and capacity has improved over the years, but it still cannot keep pace with the power consumption demands of today's mobile devices. This key limiter has led to a strong research emphasis on extending battery lifetime by minimizing energy consumption, primarily using software optimizations. This thesis presents two strategies that attempt to optimize mobile device energy consumption with negligible impact on user perception and quality of service (QoS). The first strategy proposes an application and user interaction aware middleware framework that takes advantage of user idle time between interaction events of the foreground application to optimize CPU and screen backlight energy consumption. The framework dynamically classifies mobile device applications based on their received interaction patterns, then invokes a number of different power management algorithms to adjust processor frequency and screen backlight levels accordingly. The second strategy proposes the usage of machine learning techniques to learn a user's mobile device usage pattern pertaining to spatiotemporal and device contexts, and then predict energy-optimal data and location interface configurations. By learning where and when a mobile device user uses certain power-hungry interfaces (3G, WiFi, and GPS), the techniques, which include variants of linear discriminant analysis, linear logistic regression, non-linear logistic regression, and k-nearest neighbor, are able to dynamically turn off unnecessary interfaces at runtime in order to save energy.

  10. Growth and physiological responses to surgical and gastric radio transmitter implantation techniques in subyearling chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Martinelli, T.L.; Hansel, H.C.; Shively, R.S.

    1998-01-01

    We examined the effects of surgical and gastric transmitter implantation techniques on the growth, general physiology and behavior of 230 subyearling chinook salmon (Oncorhynchus tshawytscha, Walbaum) (100 mm-154 mm fork length). The transmitter weighed 1.3 g in air (0.9 g in water) and comprised, on average, 6% of the body weight of the fish (in air). Individuals were randomly assigned to an experimental group (control, surgical or gastric) and a sampling period (day 5 or day 21). Relative growth rate was expressed as% body weight gained/day. General condition was assessed by necropsy. Physiological response variables included hematocrit, leucocrit and plasma protein concentration. The mean relative growth rates of control, surgical and gastric fish were not significantly different at day 5. By day 21, the gastric group had a significantly lower relative growth rate (1.3%) as compared to the surgical group (1.8%) and the control group (1.9%) (P = 0.0001). Mean hematocrit values were significantly lower in the surgical (41.8%) and gastric (42.2%) groups as compared to controls (47.3%) at day 5 (P = 0.01), but all were within normal range for salmonids. No significant differences in hematocrit values were detected at day 21. Leucocrit values for all groups were ??? 1% in 99% of the fish. Both tagged groups had significantly lower mean plasma protein levels as compared to controls at day 5 (P = 0.001) and day 21 (P = 0.0001). At day 21 the gastric group (64.4 g 100 m1-1) had significantly lower mean plasma protein levels than the surgical group (68.8 g 100 ml-1) (P = 0.0001). Necropsies showed decreasing condition of gastrically tagged fish over time, and increasing condition of surgical fish. Paired releases of surgically and gastrically implanted yearling chinook salmon in the lower Columbia River in spring, 1996 revealed few significant differences in migration behavior through two reservoirs. We conclude that gastrically implanted fish show decreased growth and

  11. High-level power analysis and optimization techniques

    NASA Astrophysics Data System (ADS)

    Raghunathan, Anand

    1997-12-01

    This thesis combines two ubiquitous trends in the VLSI design world--the move towards designing at higher levels of design abstraction, and the increasing importance of power consumption as a design metric. Power estimation and optimization tools are becoming an increasingly important part of design flows, driven by a variety of requirements such as prolonging battery life in portable computing and communication devices, thermal considerations and system cooling and packaging costs, reliability issues (e.g. electromigration, ground bounce, and I-R drops in the power network), and environmental concerns. This thesis presents a suite of techniques to automatically perform power analysis and optimization for designs at the architecture or register-transfer, and behavior or algorithm levels of the design hierarchy. High-level synthesis refers to the process of synthesizing, from an abstract behavioral description, a register-transfer implementation that satisfies the desired constraints. High-level synthesis tools typically perform one or more of the following tasks: transformations, module selection, clock selection, scheduling, and resource allocation and assignment (also called resource sharing or hardware sharing). High-level synthesis techniques for minimizing the area, maximizing the performance, and enhancing the testability of the synthesized designs have been investigated. This thesis presents high-level synthesis techniques that minimize power consumption in the synthesized data paths. This thesis investigates the effects of resource sharing on the power consumption in the data path, provides techniques to efficiently estimate power consumption during resource sharing, and resource sharing algorithms to minimize power consumption. The RTL circuit that is obtained from the high-level synthesis process can be further optimized for power by applying power-reducing RTL transformations. This thesis presents macro-modeling and estimation techniques for switching

  12. Arthroscopic-Assisted Acromioclavicular Joint Reconstruction Using the TightRope Device With Allograft Augmentation: Surgical Technique

    PubMed Central

    Frank, Rachel M.; Trenhaile, Scott W.

    2015-01-01

    Surgical management of acromioclavicular (AC) joint separations remains challenging, especially in the revision setting. Most commonly, Rockwood type I and II injuries are managed nonoperatively whereas type IV, V, and VI injuries are managed with surgery. Type III separations are more controversial, with evidence supporting both nonoperative and operative treatment options. Multiple different arthroscopic techniques have been described; however, there is no current gold standard. AC joint reconstruction with the TightRope device (Arthrex, Naples, FL) with the patient in the lateral decubitus position is a method of restoring joint stability that allows for a minimally invasive, low-profile fixation construct using a single drill hole through the clavicle. Allograft augmentation of this fixation construct helps to eliminate the stress risers potentially created by this device while increasing overall repair construct stability. The purpose of this article is to describe the surgical technique for arthroscopic AC joint reconstruction using a TightRope device with allograft augmentation. PMID:26759765

  13. Optimized evaporation technique for leachate treatment: Small scale implementation.

    PubMed

    Benyoucef, Fatima; Makan, Abdelhadi; El Ghmari, Abderrahman; Ouatmane, Aziz

    2016-04-01

    This paper introduces an optimized evaporation technique for leachate treatment. For this purpose and in order to study the feasibility and measure the effectiveness of the forced evaporation, three cuboidal steel tubs were designed and implemented. The first control-tub was installed at the ground level to monitor natural evaporation. Similarly, the second and the third tub, models under investigation, were installed respectively at the ground level (equipped-tub 1) and out of the ground level (equipped-tub 2), and provided with special equipment to accelerate the evaporation process. The obtained results showed that the evaporation rate at the equipped-tubs was much accelerated with respect to the control-tub. It was accelerated five times in the winter period, where the evaporation rate was increased from a value of 0.37 mm/day to reach a value of 1.50 mm/day. In the summer period, the evaporation rate was accelerated more than three times and it increased from a value of 3.06 mm/day to reach a value of 10.25 mm/day. Overall, the optimized evaporation technique can be applied effectively either under electric or solar energy supply, and will accelerate the evaporation rate from three to five times whatever the season temperature.

  14. Range of Hip Joint Motion in Developmental Dysplasia of the Hip Patients Following Total Hip Arthroplasty With the Surgical Technique Using the Concept of Combined Anteversion: A Study of Crowe I and II Patients.

    PubMed

    Zhang, Jingwei; Wei, Jianhe; Mao, Yuanqing; Li, Huiwu; Xie, Youzhuan; Zhu, Zhenan

    2015-12-01

    The combined anteversion surgical technique has been proposed and used in clinical practice. To more objectively evaluate the feasibility of this surgical technique using combined anteversion concept for DDH patients, we studied 34 DDH patients (40 hips) in this research. Every patient underwent pelvic CT scans before and after surgery and the HHSs were recorded. Optimal range of joint motion was measured using a three-dimensional reconstruction technique and a dynamic measurement technique. The results revealed that joint function met the requirements of daily life and the range of motion was not over-limited by impingement between the prosthesis and the skeleton. Moreover, the combined anteversion was found to be the most critical parameter in this study. PMID:26228491

  15. Range of Hip Joint Motion in Developmental Dysplasia of the Hip Patients Following Total Hip Arthroplasty With the Surgical Technique Using the Concept of Combined Anteversion: A Study of Crowe I and II Patients.

    PubMed

    Zhang, Jingwei; Wei, Jianhe; Mao, Yuanqing; Li, Huiwu; Xie, Youzhuan; Zhu, Zhenan

    2015-12-01

    The combined anteversion surgical technique has been proposed and used in clinical practice. To more objectively evaluate the feasibility of this surgical technique using combined anteversion concept for DDH patients, we studied 34 DDH patients (40 hips) in this research. Every patient underwent pelvic CT scans before and after surgery and the HHSs were recorded. Optimal range of joint motion was measured using a three-dimensional reconstruction technique and a dynamic measurement technique. The results revealed that joint function met the requirements of daily life and the range of motion was not over-limited by impingement between the prosthesis and the skeleton. Moreover, the combined anteversion was found to be the most critical parameter in this study.

  16. Surgical approach in primary total hip arthroplasty: anatomy, technique and clinical outcomes

    PubMed Central

    Petis, Stephen; Howard, James L.; Lanting, Brent L.; Vasarhelyi, Edward M.

    2015-01-01

    Total hip arthroplasty (THA) has revolutionized the treatment of hip arthritis. A number of surgical approaches to the hip joint exist, each with unique advantages and disadvantages. The most commonly used approaches include the direct anterior, direct lateral and posterior approaches. A number of technical intricacies allow safe and efficient femoral and acetabular reconstruction when using each approach. Hip dislocation, abductor insufficiency, fracture and nerve injury are complications of THA, although their relative risk varies by approach. Numerous clinical trials have sought to elicit differences in patient-reported outcomes, complication rates and return to function among the surgical approaches. This review outlines some of the technical pearls of performing a THA through either a direct anterior, direct lateral or posterior approach. A literature review outlines the impact of surgical approach on clinical outcomes and clinically relevant complication rates. PMID:25799249

  17. Application of multivariable search techniques to structural design optimization

    NASA Technical Reports Server (NTRS)

    Jones, R. T.; Hague, D. S.

    1972-01-01

    Multivariable optimization techniques are applied to a particular class of minimum weight structural design problems: the design of an axially loaded, pressurized, stiffened cylinder. Minimum weight designs are obtained by a variety of search algorithms: first- and second-order, elemental perturbation, and randomized techniques. An exterior penalty function approach to constrained minimization is employed. Some comparisons are made with solutions obtained by an interior penalty function procedure. In general, it would appear that an interior penalty function approach may not be as well suited to the class of design problems considered as the exterior penalty function approach. It is also shown that a combination of search algorithms will tend to arrive at an extremal design in a more reliable manner than a single algorithm. The effect of incorporating realistic geometrical constraints on stiffener cross-sections is investigated. A limited comparison is made between minimum weight cylinders designed on the basis of a linear stability analysis and cylinders designed on the basis of empirical buckling data. Finally, a technique for locating more than one extremal is demonstrated.

  18. A technique for integrating engine cycle and aircraft configuration optimization

    NASA Technical Reports Server (NTRS)

    Geiselhart, Karl A.

    1994-01-01

    A method for conceptual aircraft design that incorporates the optimization of major engine design variables for a variety of cycle types was developed. The methodology should improve the lengthy screening process currently involved in selecting an appropriate engine cycle for a given application or mission. The new capability will allow environmental concerns such as airport noise and emissions to be addressed early in the design process. The ability to rapidly perform optimization and parametric variations using both engine cycle and aircraft design variables, and to see the impact on the aircraft, should provide insight and guidance for more detailed studies. A brief description of the aircraft performance and mission analysis program and the engine cycle analysis program that were used is given. A new method of predicting propulsion system weight and dimensions using thermodynamic cycle data, preliminary design, and semi-empirical techniques is introduced. Propulsion system performance and weights data generated by the program are compared with industry data and data generated using well established codes. The ability of the optimization techniques to locate an optimum is demonstrated and some of the problems that had to be solved to accomplish this are illustrated. Results from the application of the program to the analysis of three supersonic transport concepts installed with mixed flow turbofans are presented. The results from the application to a Mach 2.4, 5000 n.mi. transport indicate that the optimum bypass ratio is near 0.45 with less than 1 percent variation in minimum gross weight for bypass ratios ranging from 0.3 to 0.6. In the final application of the program, a low sonic boom fix a takeoff gross weight concept that would fly at Mach 2.0 overwater and at Mach 1.6 overland is compared with a baseline concept of the same takeoff gross weight that would fly Mach 2.4 overwater and subsonically overland. The results indicate that for the design mission

  19. An Alternative Surgical Technique for Repair of Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery

    PubMed Central

    Kim, Young-su; Lee, Mina; Cho, Yang Hyun; Yang, Ji-Hyuk; Jun, Tae-Gook

    2014-01-01

    Background For the surgical management of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), there have been various techniques that reduce the tension and kinking of the coronary artery during reimplantation to the aorta. The aim of this study is to describe the results of our modified technique of coronary reimplantation for the treatment of ALCAPA. Methods Between October 2003 and February 2011, seven patients underwent coronary reimplantation with the modified technique (tubing formation with the sinus wall of the pulmonary artery and trapdoor formation at the site of implantation in the aorta). The median follow-up duration was 52 months (range, 4 to 72 months). Clinical outcomes and serial echocardiographic data were reviewed. Results There was no mortality. One patient had a small amount of cerebral hemorrhage postoperatively and improved without any sequelae. Another patient had left diaphragm palsy and underwent diaphragm plication. Follow-up echocardiogram showed that all patients had normal ventricular function without chamber enlargement. Conclusion Our modified technique (tubing formation with the sinus wall of the pulmonary artery and trapdoor formation at the site of implantation in the aorta) demonstrated successful clinical outcomes. We conclude that this surgical technique can be a potential alternative for the treatment of ALCAPA. PMID:25207218

  20. Breast Cancer-Related Arm Lymphedema: Incidence Rates, Diagnostic Techniques, Optimal Management and Risk Reduction Strategies

    SciTech Connect

    Shah, Chirag; Vicini, Frank A.

    2011-11-15

    As more women survive breast cancer, long-term toxicities affecting their quality of life, such as lymphedema (LE) of the arm, gain importance. Although numerous studies have attempted to determine incidence rates, identify optimal diagnostic tests, enumerate efficacious treatment strategies and outline risk reduction guidelines for breast cancer-related lymphedema (BCRL), few groups have consistently agreed on any of these issues. As a result, standardized recommendations are still lacking. This review will summarize the latest data addressing all of these concerns in order to provide patients and health care providers with optimal, contemporary recommendations. Published incidence rates for BCRL vary substantially with a range of 2-65% based on surgical technique, axillary sampling method, radiation therapy fields treated, and the use of chemotherapy. Newer clinical assessment tools can potentially identify BCRL in patients with subclinical disease with prospective data suggesting that early diagnosis and management with noninvasive therapy can lead to excellent outcomes. Multiple therapies exist with treatments defined by the severity of BCRL present. Currently, the standard of care for BCRL in patients with significant LE is complex decongestive physiotherapy (CDP). Contemporary data also suggest that a multidisciplinary approach to the management of BCRL should begin prior to definitive treatment for breast cancer employing patient-specific surgical, radiation therapy, and chemotherapy paradigms that limit risks. Further, prospective clinical assessments before and after treatment should be employed to diagnose subclinical disease. In those patients who require aggressive locoregional management, prophylactic therapies and the use of CDP can help reduce the long-term sequelae of BCRL.

  1. Techniques for developing approximate optimal advanced launch system guidance

    NASA Technical Reports Server (NTRS)

    Feeley, Timothy S.; Speyer, Jason L.

    1991-01-01

    An extension to the authors' previous technique used to develop a real-time guidance scheme for the Advanced Launch System is presented. The approach is to construct an optimal guidance law based upon an asymptotic expansion associated with small physical parameters, epsilon. The trajectory of a rocket modeled as a point mass is considered with the flight restricted to an equatorial plane while reaching an orbital altitude at orbital injection speeds. The dynamics of this problem can be separated into primary effects due to thrust and gravitational forces, and perturbation effects which include the aerodynamic forces and the remaining inertial forces. An analytic solution to the reduced-order problem represented by the primary dynamics is possible. The Hamilton-Jacobi-Bellman or dynamic programming equation is expanded in an asymptotic series where the zeroth-order term (epsilon = 0) can be obtained in closed form.

  2. Review of optimization techniques of polygeneration systems for building applications

    NASA Astrophysics Data System (ADS)

    Y, Rong A.; Y, Su; R, Lahdelma

    2016-08-01

    Polygeneration means simultaneous production of two or more energy products in a single integrated process. Polygeneration is an energy-efficient technology and plays an important role in transition into future low-carbon energy systems. It can find wide applications in utilities, different types of industrial sectors and building sectors. This paper mainly focus on polygeneration applications in building sectors. The scales of polygeneration systems in building sectors range from the micro-level for a single home building to the large- level for residential districts. Also the development of polygeneration microgrid is related to building applications. The paper aims at giving a comprehensive review for optimization techniques for designing, synthesizing and operating different types of polygeneration systems for building applications.

  3. On improving storm surge forecasting using an adjoint optimal technique

    NASA Astrophysics Data System (ADS)

    Li, Yineng; Peng, Shiqiu; Yan, Jing; Xie, Lian

    2013-12-01

    A three-dimensional ocean model and its adjoint model are used to simultaneously optimize the initial conditions (IC) and the wind stress drag coefficient (Cd) for improving storm surge forecasting. To demonstrate the effect of this proposed method, a number of identical twin experiments (ITEs) with a prescription of different error sources and two real data assimilation experiments are performed. Results from both the idealized and real data assimilation experiments show that adjusting IC and Cd simultaneously can achieve much more improvements in storm surge forecasting than adjusting IC or Cd only. A diagnosis on the dynamical balance indicates that adjusting IC only may introduce unrealistic oscillations out of the assimilation window, which can be suppressed by the adjustment of the wind stress when simultaneously adjusting IC and Cd. Therefore, it is recommended to simultaneously adjust IC and Cd to improve storm surge forecasting using an adjoint technique.

  4. Early surgical intervention and optimal medical treatment for Candida parapsilosis endocarditis.

    PubMed

    Toyoda, Shigeru; Tajima, Emi; Fukuda, Reiko; Masawa, Taito; Inami, Shu; Amano, Hirohisa; Arikawa, Takuo; Yoshida, Atsushi; Hishinuma, Akira; Inoue, Teruo

    2015-01-01

    We herein report the case of a 72-year-old man with endocarditis of the aortic valve who underwent urgent aortic valve replacement 36 hours after admission due to an aggravation of aortic valve regurgitation. Postoperative cultures of the blood and site of valve vegetation identified Candida parapsilosis as a pathogen. Antifungal therapy with amphotericin B and fluconazole was initiated after surgical treatment. Thereafter, the patient displayed a favorable clinical course. Candida parapsilosis endocarditis involving the native valves is extremely rare and associated with a very high mortality rate. Prompt surgical treatment and the aggressive use of antifungal agents are required to save the patient's life.

  5. Optimal technique for maximal forward rotating vaults in men's gymnastics.

    PubMed

    Hiley, Michael J; Jackson, Monique I; Yeadon, Maurice R

    2015-08-01

    In vaulting a gymnast must generate sufficient linear and angular momentum during the approach and table contact to complete the rotational requirements in the post-flight phase. This study investigated the optimization of table touchdown conditions and table contact technique for the maximization of rotation potential for forwards rotating vaults. A planar seven-segment torque-driven computer simulation model of the contact phase in vaulting was evaluated by varying joint torque activation time histories to match three performances of a handspring double somersault vault by an elite gymnast. The closest matching simulation was used as a starting point to maximize post-flight rotation potential (the product of angular momentum and flight time) for a forwards rotating vault. It was found that the maximized rotation potential was sufficient to produce a handspring double piked somersault vault. The corresponding optimal touchdown configuration exhibited hip flexion in contrast to the hyperextended configuration required for maximal height. Increasing touchdown velocity and angular momentum lead to additional post-flight rotation potential. By increasing the horizontal velocity at table touchdown, within limits obtained from recorded performances, the handspring double somersault tucked with one and a half twists, and the handspring triple somersault tucked became theoretically possible.

  6. Optimal exposure techniques for iodinated contrast enhanced breast CT

    NASA Astrophysics Data System (ADS)

    Glick, Stephen J.; Makeev, Andrey

    2016-03-01

    Screening for breast cancer using mammography has been very successful in the effort to reduce breast cancer mortality, and its use has largely resulted in the 30% reduction in breast cancer mortality observed since 1990 [1]. However, diagnostic mammography remains an area of breast imaging that is in great need for improvement. One imaging modality proposed for improving the accuracy of diagnostic workup is iodinated contrast-enhanced breast CT [2]. In this study, a mathematical framework is used to evaluate optimal exposure techniques for contrast-enhanced breast CT. The ideal observer signal-to-noise ratio (i.e., d') figure-of-merit is used to provide a task performance based assessment of optimal acquisition parameters under the assumptions of a linear, shift-invariant imaging system. A parallel-cascade model was used to estimate signal and noise propagation through the detector, and a realistic lesion model with iodine uptake was embedded into a structured breast background. Ideal observer performance was investigated across kVp settings, filter materials, and filter thickness. Results indicated many kVp spectra/filter combinations can improve performance over currently used x-ray spectra.

  7. Optimal technique for maximal forward rotating vaults in men's gymnastics.

    PubMed

    Hiley, Michael J; Jackson, Monique I; Yeadon, Maurice R

    2015-08-01

    In vaulting a gymnast must generate sufficient linear and angular momentum during the approach and table contact to complete the rotational requirements in the post-flight phase. This study investigated the optimization of table touchdown conditions and table contact technique for the maximization of rotation potential for forwards rotating vaults. A planar seven-segment torque-driven computer simulation model of the contact phase in vaulting was evaluated by varying joint torque activation time histories to match three performances of a handspring double somersault vault by an elite gymnast. The closest matching simulation was used as a starting point to maximize post-flight rotation potential (the product of angular momentum and flight time) for a forwards rotating vault. It was found that the maximized rotation potential was sufficient to produce a handspring double piked somersault vault. The corresponding optimal touchdown configuration exhibited hip flexion in contrast to the hyperextended configuration required for maximal height. Increasing touchdown velocity and angular momentum lead to additional post-flight rotation potential. By increasing the horizontal velocity at table touchdown, within limits obtained from recorded performances, the handspring double somersault tucked with one and a half twists, and the handspring triple somersault tucked became theoretically possible. PMID:26026290

  8. Inferior Alveolar Nerve Lateralization and Transposition for Dental Implant Placement. Part I: a Systematic Review of Surgical Techniques

    PubMed Central

    Juodzbalys, Gintaras

    2015-01-01

    ABSTRACT Objectives The purpose of this first part of a two-part series was to review the literature concerning the indications, contraindications, advantages, disadvantages and surgical techniques of the lateralization and transposition of the inferior alveolar nerve, followed by the placement of an implant in an edentulous atrophic posterior mandible. Material and Methods A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed and PMC database, academic sites and books. The articles were searched from January 1997 to July 2014 and comprised English-language articles that included adult patients between 18 and 80 years old with minimal residual bone above the mandibular canal who had undergone inferior alveolar nerve (IAN) repositioning with a minimum 6 months of follow-up. Results A total of 16 studies were included in this review. Nine were related to IAN transposition, 4 to IAN lateralization and 3 to both transposition and lateralization. Implant treatment results and complications were presented. Conclusions Inferior alveolar nerve lateralization and transposition in combination with the installation of dental implants is sometimes the only possible procedure to help patients to obtain a fixed prosthesis, in edentulous atrophic posterior mandibles. With careful pre-operative surgical and prosthetic planning, imaging, and extremely precise surgical technique, this procedure can be successfully used for implant placement in edentulous posterior mandibular segments. PMID:25937873

  9. Robotic-assisted transperitoneal nephron-sparing surgery for small renal masses with associated surgical procedures: surgical technique and preliminary experience.

    PubMed

    Ceccarelli, Graziano; Codacci-Pisanelli, Massimo; Patriti, Alberto; Ceribelli, Cecilia; Biancafarina, Alessia; Casciola, Luciano

    2013-09-01

    Small renal masses (T1a) are commonly diagnosed incidentally and can be treated with nephron-sparing surgery, preserving renal function and obtaining the same oncological results as radical surgery. Bigger lesions (T1b) may be treated in particular situations with a conservative approach too. We present our surgical technique based on robotic assistance for nephron-sparing surgery. We retrospectively analysed our series of 32 consecutive patients (two with 2 tumours and one with 4 bilateral tumours), for a total of 37 robotic nephron-sparing surgery (RNSS) performed between June 2008 and July 2012 by a single surgeon (G.C.). The technique differs depending on tumour site and size. The mean tumour size was 3.6 cm; according to the R.E.N.A.L. Nephrometry Score 9 procedures were considered of low, 14 of moderate and 9 of hight complexity with no conversion in open surgery. Vascular clamping was performed in 22 cases with a mean warm ischemia time of 21.5 min and the mean total procedure time was 149.2 min. Mean estimated blood loss was 187.1 ml. Mean hospital stay was 4.4 days. Histopathological evaluation confirmed 19 cases of clear cell carcinoma (all the multiple tumours were of this nature), 3 chromophobe tumours, 1 collecting duct carcinoma, 5 oncocytomas, 1 leiomyoma, 1 cavernous haemangioma and 2 benign cysts. Associated surgical procedures were performed in 10 cases (4 cholecystectomies, 3 important lyses of peritoneal adhesions, 1 adnexectomy, 1 right hemicolectomy, 1 hepatic resection). The mean follow-up time was 28.1 months ± 12.3 (range 6-54). Intraoperative complications were 3 cases of important bleeding not requiring conversion to open or transfusions. Regarding post-operative complications, there were a bowel occlusion, 1 pleural effusion, 2 pararenal hematoma, 3 asymptomatic DVT (deep vein thrombosis) and 1 transient increase in creatinine level. There was no evidence of tumour recurrence in the follow-up. RNSS is a safe and feasible technique

  10. Surgical Airway

    PubMed Central

    Patel, Sapna A; Meyer, Tanya K

    2014-01-01

    Close to 3% of all intubation attempts are considered difficult airways, for which a plan for a surgical airway should be considered. Our article provides an overview of the different types of surgical airways. This article provides a comprehensive review of the main types of surgical airways, relevant anatomy, necessary equipment, indications and contraindications, preparation and positioning, technique, complications, and tips for management. It is important to remember that the placement of a surgical airway is a lifesaving procedure and should be considered in any setting when one “cannot intubate, cannot ventilate”. PMID:24741501

  11. Surgical technique: hemi-extensor carpi radialis brevis tenodesis for stabilizing the midcarpal joint in Ehlers-Danlos syndrome.

    PubMed

    Krijgh, David D; Harley, Oliver J; Hovius, Steven E; Coert, J Henk; Walbeehm, Erik T

    2014-10-01

    Patients with the hypermobility type of Ehlers-Danlos (EDS-HT) often complain of wrist pain, usually originating from subluxations. As a result of the laxity, wrist function in these patients can be highly limited. This paper presents a surgical technique that stabilizes the lunocapitate joint with the use of an extensor carpi radialis brevis strip. Five patients with confirmed EDS-HT were treated with an extensor carpi radialis brevis tenodesis for their midcarpal instability. Two patients presented with complications following surgery, one major and one minor. This paper presents a potentially satisfactory surgical solution to recurrent midcarpal instability in EDS-HT patients and demonstrates that the use of an autologous tendon might be feasible in spite of a background of abnormal collagen metabolism. PMID:25194773

  12. Isolated Avulsion of Extensor Carpi Radialis Longus and Brachioradialis Origins: A Case Report and Surgical Repair Technique.

    PubMed

    Salazar, Dane; Hazel, Antony; Marra, Guido

    2015-10-01

    The mobile wad of the elbow provides a tremendous mechanical advantage with respect to elbow flexion and wrist extension. Injury to these structures causes significant upper extremity dysfunction. In this article, we report the case of a 31-year-old right hand-dominant man who sustained an isolated avulsion of the extensor carpi radialis longus and brachioradialis origins from the lateral epicondyle and lateral supracondylar ridge. We describe our diagnostic workup and present our surgical repair technique. The literature includes only 2 case reports of bony avulsion fracture of the origin of the brachioradialis and, up until now, no case reports of isolated avulsion of the extensor carpi radialis longus and brachioradialis origins. Given the biomechanics and anatomy of the dorsal mobile wad, we posit that our patient's injury occurred secondary to an overwhelming eccentric muscle contracture. The rarity of this injury led to a substantial delay in diagnosis. Because of the potential morbidity, surgical intervention is recommended.

  13. [Approach to the jugular foramen and related structures - an analysis of the surgical technique based on cadaver simulation].

    PubMed

    Ladziński, Piotr; Maliszewski, Mariusz; Kaspera, Wojciech; Szczygieł, Majchrzak; Tymowski, Michał

    2011-01-01

    This study presents consecutive stages of the approach to the jugular foramen and related structures. Eleven simulations of the approach were performed on non-fixed human cadavers without any known pathologies in the head and neck. The consecutive stages of the procedure were documented with photographs and schematic diagrams. The starting point for the discussed approach is removal of the mastoid and petrosal parts of the temporal bone, as well as the jugular process and the jugular tuberculum. It allows penetration of the jugular foramen from the back. Widening of the approach enables penetration of the jugular foramen from above and the front. Approach to the jugular foramen is a reproducible technique, which provides surgical penetration of this foramen and related structures. This approach is particularly useful in the surgical treatment of tumours expanding in the petrous pyramid, surroundings of the petrosal part of the internal carotid artery, cerebellopontine angle, subtemporal fossa and nervous-vascular bundle of the neck. PMID:21866483

  14. In vitro biomechanical evaluation of four surgical techniques for fusion of equine centrodistal and tarsometatarsal joints.

    PubMed

    Biedrzycki, Adam H; Grant, Barrie G; Nemke, Brett; Morello, Samantha L; Markel, Mark D

    2016-10-01

    OBJECTIVE To evaluate the biomechanical properties of 4 methods for fusion of the centrodistal and tarsometatarsal joints in horses and compare them among each other and with control tarsi. SAMPLE 24 sets of paired tarsi without substantial signs of osteoarthritis harvested from equine cadavers. PROCEDURES Test constructs (n = 6/type) were prepared from 1 tarsus from each pair to represent surgical drilling; 2 medially to laterally placed kerf-cut cylinders (MLKCs); a single large, dorsally applied kerf-cut cylinder (DKC); and a dorsomedially applied locking compression plate (DMLCP). Constructs and their contralateral control tarsi were evaluated in 4-point bending in the dorsoplantar, lateromedial, and mediolateral directions; internal and external rotation; and axial compression. Bending, torsional, and axial stiffness values were calculated. RESULTS Mean stiffness values were consistently lower for surgical drilling constructs than for contralateral control tarsi. Over all biomechanical testing, surgical drilling significantly reduced joint stability. The MLKC constructs had superior biomechanical properties to those of control tarsi for 4-point bending but inferior properties for external and internal rotation. The DMLCP and DKC constructs were superior to control tarsi in dorsoplantar, rotational, and axial compression directions only; DMLCP constructs had no superior stiffness in lateromedial or mediolateral directions. Only the DKC constructs had greater stiffness in the mediolateral direction than did control tarsi. Over all biomechanical testing, DMLCP and DKC constructs were superior to the other constructs. CONCLUSIONS AND CLINICAL RELEVANCE These biomechanical results suggested that a surgical drilling approach to joint fusion may reduce tarsal stability in horses without clinical osteoarthritis, compared with stability with no intervention, whereas the DMLCP and DKC approaches may significantly enhance stability. PMID:27668578

  15. [Nephropexy in the course of time. Aspects of an historical surgical technique].

    PubMed

    Hatzinger, M; Langbein, S; de la Rosette, J; Sohn, M; Alken, P

    2007-02-01

    The first successful nephropexy was performed in the year 1881. From this time, surgical therapy of nephroptosis has always been a subject of discussion. A partly uncritical acceptance led to nephropexy being the most performed urological operation at the beginning of the 20th century, with up to 200 different surgical variations. As early as the 15th century, a first description of ren mobilis was made by Alessius de Pedemontanus. The first surgical intervention for the treatment of nephroptosis was performed by Gilmore in 1870. In 1877, the American Dowell from New Orleans tried a fixation of the kidney through a seton, however, this operation failed. Eventually in 1881, Eugen Hahn from Berlin was able to perform the first successful nephropexy, he named this method "nephroraphy". In 1882, the first modification was made by Bassini with sutures through the renal capsule. Finally, the gynaecologist George Edebohl led nephropexy into a great popularity and secured the method through numerous technical innovations. By 1936, approximately 170 different surgical methods existed for fixation of the kidney. An accurate diagnosis is imperative before performing nephropexy. There were times in which this operation was carried out much too often and, therefore, had a bad reputation. However, it is not correct to drop nephropexy altogether as some would prefer. The statement by Professor Voelcker from Halle in the year 1911 that for all those who have a urinary obstruction and those with a beginning dilation, nephropexy is still justified and may - when correctly performed provide many blessings". Nothing needs to be added to this. PMID:17221244

  16. Surgical closure of persistent arterial duct with minimal invasive anterior thoracotomy: an alternative technique.

    PubMed

    Fouilloux, Virginie; Gran, Célia; Kreitmann, Bernard

    2014-10-01

    Surgical approach for persistent ductus arteriosus ligation is typically a left lateral thoracotomy opening the pleural-space with left lung retraction. We describe an alternative approach, with a minimally invasive anterior parasternal incision. This is particularly adapted to preterm infants weighing less than 1.5 kg. This approach ensures a good exposure of vessels. We believe that it is safe, reliable and reproducible. The learning curve should not be an issue for surgeons used to manage low weight patients.

  17. Modern surgical techniques for management of soft tissue sarcomas involving the spine: outcomes and complications.

    PubMed

    Mattei, Tobias A; Teles, Alisson R; Mendel, Ehud

    2015-04-01

    Several types of soft tissue sarcomas may locally extend to the spine. The best therapeutic strategy for such lesions strongly depends on the histological diagnosis. In this article the authors provide an up-to-date review of current guidelines regarding the management of soft tissue sarcomas involving the spine. Special attention is given to outcomes and complications of modern surgical series in order to highlight current challenges in the management of such lesions.

  18. An in-use microbiological comparison of two surgical hand disinfection techniques in cardiothoracic surgery: hand rubbing versus hand scrubbing.

    PubMed

    Carro, C; Camilleri, L; Traore, O; Badrikian, L; Legault, B; Azarnoush, K; Dualé, C; De Riberolles, C

    2007-09-01

    Surgical site infection after heart surgery increases morbidity and mortality. The method of presurgical hand disinfection could influence the infection risk. From February to April 2003, we compared the microbiological efficacy of hand-rubbing (R) and hand-scrubbing (S) procedures. The surgical team alternately used hand-scrubbing or hand-rubbing techniques every two weeks. Fingertip impressions were taken before and immediately after hand disinfection, every 2h and at the end of the operation. Acceptability of hand rubbing was assessed by a questionnaire. Mean durations of surgical procedures were 259+/-68 and 244+/-69min for groups S and R respectively (P=0.43). Bacterial counts immediately after hand disinfection were comparable with the two techniques, but significantly lower in group R at the end of surgery. No differences were observed between the percentages of negative samples taken after 2h, 4h and at the end of surgery between the two groups. Bacterial skin flora reduction immediately after hand disinfection, after 2h and 4h of operating time and at the end of surgery was better in group R, but the difference was not statistically significant. Before surgery, the hand-rubbing method with alcohol solution preceded by hand washing with mild neutral soap is as effective as hand scrubbing to reduce bacterial counts on hands. It decreased the bacterial counts both immediately after hand disinfection and at the end of long cardiothoracic surgical procedures. The acceptability of hand rubbing was excellent and it can be considered to be a valid alternative to the conventional hand-scrubbing protocol.

  19. Alveolar Antral Artery: Review of Surgical Techniques Involving this Anatomic Structure

    PubMed Central

    Rahpeyma, Amin; Khajehahmadi, Saeedeh

    2014-01-01

    Introduction: The horizontal bony canal in the lateral maxillary wall is the site of anastomosis between the arterial branches from the posterior superior alveolar artery (PSAa) and the infraorbital artery. This anatomic structure is known as the ‘alveolar antral artery’. Materials and Methods: We performed a literature review. The anatomic location of the alveolar antral artery in the lateral maxillary sinus wall was researched and its importance in surgical procedures routinely performed on this bony wall discussed. Results: This artery can be accidentally involved during surgical procedures on the lateral maxillary sinus wall, such as open sinus lift surgery, horizontal osteotomy of the maxilla, Le Fort I fracture treatment, and Caldwell-Luc surgeries. Conclusion: The alveolar antral artery is an important anatomic structure in the lateral maxillary sinus wall. A preoperative cone beam computed tomography (CBCT) scan can be used as a good diagnostic procedure to reduce surgical complications in suspected cases as well as conditions that may involve this artery. PMID:24744995

  20. Production of piglets with sexed semen employing a non-surgical insemination technique.

    PubMed

    Grossfeld, R; Klinc, P; Sieg, B; Rath, D

    2005-05-01

    The aim of the present study was to ascertain whether multiparous sows could successfully be inseminated with sexed semen non-surgically. Spermatozoa were stained with Hoechst 33342 and separated flowcytometrically in X- and Y-chromosome bearing sperm populations employing the Beltsville Sperm Sexing Technology (BSST). After weaning, estrus was induced in sows with PMSG and hCG. Animals were inseminated once per estrus non-surgically with a specially designed catheter into the tip of the uterine horn, employing 50x10(6) of either sexed or non-sexed spermatozoa diluted in 2 ml Androhep. Pregnant sows were allowed to go to term. Mean pregnancy rate from inseminations with unsexed spermatozoa was 54.5% whereas inseminations with sexed spermatozoa resulted in 33.3% pregnant sows. All but one piglet born after insemination with sexed semen were of the predicted sex. The sex of those piglets born after inseminations with non-sexed spermatozoa was 61.1% for male and 38.9% for female sex. It is concluded that non-surgically inseminations with flowcytometrically sexed spermatozoa can be conducted successfully. PMID:15826689

  1. Surgical hand antisepsis in veterinary practice: evaluation of soap scrubs and alcohol based rub techniques.

    PubMed

    Verwilghen, Denis R; Mainil, Jacques; Mastrocicco, Emilie; Hamaide, Annick; Detilleux, Johann; van Galen, Gaby; Serteyn, Didier; Grulke, Sigrid

    2011-12-01

    Recent studies have shown that hydro-alcoholic solutions are more efficient than traditional medicated soaps in the pre-surgical hand antisepsis of human surgeons but there is little veterinary literature on the subject. The aim of this study was to compare the efficiency of medicated soaps and a hydro-alcoholic solution prior to surgery using an in-use testing method in a veterinary setting. A preliminary trial was performed that compared the mean log(10) number of bacterial colony forming units (CFU) and the reduction factors (RF) between two 5-min hand-scrubbing sessions using different soaps, namely, povidone iodine (PVP) and chlorhexidine gluconate (CHX), and the 1.5-min application of a hydro-alcoholic rub. A clinical in-use trial was then used to compare the hydro-alcoholic rub and CHX in a surgical setting. Sampling was performed using finger printing on agar plates. The hydro-alcoholic rub and CHX had a similar immediate effect, although the sustained effect was significantly better for the hydro-alcoholic rub, while PVP had a significantly lower immediate and sustained effect. The hydro-alcoholic rub showed good efficiency in the clinical trial and could be considered as a useful alternative method for veterinary surgical hand antisepsis.

  2. Surgical Technologists

    MedlinePlus

    ... in place during the procedure, or set up robotic surgical equipment. Technologists also may handle specimens taken ... sterilization techniques, how to set up technical or robotic equipment, and preventing and controlling infections. In addition ...

  3. Optimization technique for problems with an inequality constraint

    NASA Technical Reports Server (NTRS)

    Russell, K. J.

    1972-01-01

    General technique uses a modified version of an existing technique termed the pattern search technique. New procedure called the parallel move strategy permits pattern search technique to be used with problems involving a constraint.

  4. Technique to optimize magnetic response of gelatin coated magnetic nanoparticles.

    PubMed

    Parikh, Nidhi; Parekh, Kinnari

    2015-07-01

    The paper describes the results of optimization of magnetic response for highly stable bio-functionalize magnetic nanoparticles dispersion. Concentration of gelatin during in situ co-precipitation synthesis was varied from 8, 23 and 48 mg/mL to optimize magnetic properties. This variation results in a change in crystallite size from 10.3 to 7.8 ± 0.1 nm. TEM measurement of G3 sample shows highly crystalline spherical nanoparticles with a mean diameter of 7.2 ± 0.2 nm and diameter distribution (σ) of 0.27. FTIR spectra shows a shift of 22 cm(-1) at C=O stretching with absence of N-H stretching confirming the chemical binding of gelatin on magnetic nanoparticles. The concept of lone pair electron of the amide group explains the mechanism of binding. TGA shows 32.8-25.2% weight loss at 350 °C temperature substantiating decomposition of chemically bind gelatin. The magnetic response shows that for 8 mg/mL concentration of gelatin, the initial susceptibility and saturation magnetization is the maximum. The cytotoxicity of G3 sample was assessed in Normal Rat Kidney Epithelial Cells (NRK Line) by MTT assay. Results show an increase in viability for all concentrations, the indicative probability of a stimulating action of these particles in the nontoxic range. This shows the potential of this technique for biological applications as the coated particles are (i) superparamagnetic (ii) highly stable in physiological media (iii) possibility of attaching other drug with free functional group of gelatin and (iv) non-toxic.

  5. Association between Fellowship Training, Surgical Volume, and Laparoscopic Suturing Techniques among Members of the American Association of Gynecologic Laparoscopists

    PubMed Central

    Scott, Lauren; Miladinovic, Branko; Imudia, Anthony N.; Hart, Stuart

    2016-01-01

    Study Objective. To compare surgical volume and techniques including laparoscopic suturing among members of the American Association of Gynecologic Laparoscopists (AAGL) according to fellowship training status. Design. A web-based survey was designed using Qualtrics and sent to AAGL members. Results. Minimally invasive gynecologic surgery (FMIGS) trained surgeons were more likely to perform more than 8 major conventional laparoscopic cases per month (63% versus 38%, P < 0.001, OR [95% CI] = 2.78 [1.54–5.06]) and were more likely to perform laparoscopic suturing during these cases (32% versus 16%, P < 0.004, OR [95% CI] = 2.44 [1.25–4.71]). The non-fellowship trained (NFT) surgeons in private practice were less likely to perform over 8 conventional laparoscopic cases (34% versus 51%, P = 0.03, OR [95% CI] = 0.50 [0.25–0.99]) and laparoscopic suturing during these cases (13% versus 27%, P = 0.01, OR [95% CI] = 0.39 [0.17–0.92]) compared to NFT surgeons in academic practice. Conclusion. The surgical volume and utilization of laparoscopic suturing of FMIGS trained surgeons are significantly increased compared to NFT surgeons. Academic practice setting had a positive impact on surgical volume of NFT surgeons but not on FMIGS trained surgeons. PMID:26885389

  6. Selective peripheral denervation for spasmodic torticollis: surgical technique, results, and observations in 260 cases.

    PubMed

    Bertrand, C M

    1993-08-01

    A total of 260 cases of spasmodic torticollis or of the cervical component of diffuse dystonias have been surgically treated with selective peripheral denervation of the involved muscles sparing their antagonists, after verification with electromyography and, if necessary, nerve blocks. Total or marked relief of symptoms with preservation of normal or nearly normal movements has been obtained in 88% of the patients with surgery followed by early physiotherapy. There are minimal sequelae with this approach. Selective denervation may be recommended if, after 2 years, conservative treatment, including botulinum injections, does not offer satisfactory relief of symptoms.

  7. The iLappSurgery taTME app: a modern adjunct to the teaching of surgical techniques.

    PubMed

    Atallah, S; Brady, R R W

    2016-09-01

    Application-based technology has emerged as a method of modern information communication, and this has been applied towards surgical training and education. It allows surgeons the ability to obtain portable and instant access to information that is otherwise difficult to deliver. The iLappSurgery Foundation has recently launched the transanal total mesorectal excision educational application (taTME app) which provides a useful adjunct, especially for surgeons interested in mastery of the taTME technique and its principles. The article provides a detailed review of the application, which has achieved a large user-base since its debut in June, 2016. PMID:27503235

  8. An optimal merging technique for high-resolution precipitation products: OPTIMAL MERGING OF PRECIPITATION METHOD

    SciTech Connect

    Shrestha, Roshan; Houser, Paul R.; Anantharaj, Valentine G.

    2011-04-01

    Precipitation products are currently available from various sources at higher spatial and temporal resolution than any time in the past. Each of the precipitation products has its strengths and weaknesses in availability, accuracy, resolution, retrieval techniques and quality control. By merging the precipitation data obtained from multiple sources, one can improve its information content by minimizing these issues. However, precipitation data merging poses challenges of scale-mismatch, and accurate error and bias assessment. In this paper we present Optimal Merging of Precipitation (OMP), a new method to merge precipitation data from multiple sources that are of different spatial and temporal resolutions and accuracies. This method is a combination of scale conversion and merging weight optimization, involving performance-tracing based on Bayesian statistics and trend-analysis, which yields merging weights for each precipitation data source. The weights are optimized at multiple scales to facilitate multiscale merging and better precipitation downscaling. Precipitation data used in the experiment include products from the 12-km resolution North American Land Data Assimilation (NLDAS) system, the 8-km resolution CMORPH and the 4-km resolution National Stage-IV QPE. The test cases demonstrate that the OMP method is capable of identifying a better data source and allocating a higher priority for them in the merging procedure, dynamically over the region and time period. This method is also effective in filtering out poor quality data introduced into the merging process.

  9. Clinical comparison of ultrasonic surgery and conventional surgical techniques for enucleating jaw cysts.

    PubMed

    Yaman, Z; Suer, B T

    2013-11-01

    The conventional treatment of odontogenic cysts usually involves enucleation of the cyst using rotary and manual instruments; such procedures can cause trauma to the cystic epithelium or soft tissues in the region, such as sinus membrane perforation or nerve damage. The use of ultrasonic surgery may reduce the risk of damage to soft tissues. The objective of this study was to evaluate the performance of ultrasonic surgery in removing odontogenic cysts. Eighty-two cysts were removed from 68 patients over a period of 45 months. Ultrasonic surgery was used for 34 patients and conventional surgical procedures were used for 34 control patients. Two surgeons rated the cutting efficiency, visibility of the surgical field, ease of operation, and ease of cyst epithelium removal on a 100-mm visual analogue scale. The operation time was also recorded. No major intraoperative or postoperative complications were observed, and there was no cyst recurrence. Ultrasonic surgery for enucleating jaw cysts was found to increase the operation time, but also markedly increased the visibility of the operation field. In cases where cyst enucleation is performed in difficult areas that require delicate manipulation, there is less risk of damage to vital structures such as neurovascular tissues with ultrasonic surgery.

  10. Optimization of fast dissolving etoricoxib tablets prepared by sublimation technique.

    PubMed

    Patel, D M; Patel, M M

    2008-01-01

    The purpose of this investigation was to develop fast dissolving tablets of etoricoxib. Granules containing etoricoxib, menthol, crospovidone, aspartame and mannitol were prepared by wet granulation technique. Menthol was sublimed from the granules by exposing the granules to vacuum. The porous granules were then compressed in to tablets. Alternatively, tablets were first prepared and later exposed to vacuum. The tablets were evaluated for percentage friability and disintegration time. A 3(2) full factorial design was applied to investigate the combined effect of 2 formulation variables: amount of menthol and crospovidone. The results of multiple regression analysis indicated that for obtaining fast dissolving tablets; optimum amount of menthol and higher percentage of crospovidone should be used. A surface response plots are also presented to graphically represent the effect of the independent variables on the percentage friability and disintegration time. The validity of a generated mathematical model was tested by preparing a checkpoint batch. Sublimation of menthol from tablets resulted in rapid disintegration as compared with the tablets prepared from granules that were exposed to vacuum. The optimized tablet formulation was compared with conventional marketed tablets for percentage drug dissolved in 30 min (Q(30)) and dissolution efficiency after 30 min (DE(30)). From the results, it was concluded that fast dissolving tablets with improved etoricoxib dissolution could be prepared by sublimation of tablets containing suitable subliming agent.

  11. Optimal cone size to predict positive surgical margins after cold knife conization (CKC) and the risk factors for residual disease

    PubMed Central

    Öz, Murat; Çetinkaya, Nilüfer; Korkmaz, Elmas; Seçkin, Kerem Doğa; Meydanlı, Mehmet Mutlu; Güngör, Tayfun

    2016-01-01

    Objective To determine the optimal cone size to achieve a reliable sensitivity and specificity for clear surgical margins after cold knife conization (CKC). Material and Methods The medical reports of patients who had high-grade cervical intraepithelial lesions, carcinoma in situ, or stage 1A1 microinvasive carcinoma in their CKC specimens between June 2008 and January 2015 were reviewed retrospectively. Results In total, 315 women fulfilled the inclusion criteria. The mean age of the patients was 40.7 years. The conization results were microinvasive carcinoma and high-grade squamous lesion (HSIL) for 8 and 307 patients, respectively. Ninety-nine patients had positive surgical margins. Eighty-one patients with positive cone margins underwent the repeat excisional procedure and 35 of them showed residual disease. In the univariate analyses, the patient age, menopausal status, and mean cone height parameters showed statistically significant differences between the patients with positive and negative margins. Also, residual disease was associated with the menopausal status and age of the patients. Conclusion There is no optimal cone depth that is applicable for all patients. The most important predictors for positive margins are the menopausal status of the patient and that more than two quadrants are involved. However, the menopausal status and age of the patients were still predictors for residual disease. PMID:27651725

  12. Optimal cone size to predict positive surgical margins after cold knife conization (CKC) and the risk factors for residual disease

    PubMed Central

    Öz, Murat; Çetinkaya, Nilüfer; Korkmaz, Elmas; Seçkin, Kerem Doğa; Meydanlı, Mehmet Mutlu; Güngör, Tayfun

    2016-01-01

    Objective To determine the optimal cone size to achieve a reliable sensitivity and specificity for clear surgical margins after cold knife conization (CKC). Material and Methods The medical reports of patients who had high-grade cervical intraepithelial lesions, carcinoma in situ, or stage 1A1 microinvasive carcinoma in their CKC specimens between June 2008 and January 2015 were reviewed retrospectively. Results In total, 315 women fulfilled the inclusion criteria. The mean age of the patients was 40.7 years. The conization results were microinvasive carcinoma and high-grade squamous lesion (HSIL) for 8 and 307 patients, respectively. Ninety-nine patients had positive surgical margins. Eighty-one patients with positive cone margins underwent the repeat excisional procedure and 35 of them showed residual disease. In the univariate analyses, the patient age, menopausal status, and mean cone height parameters showed statistically significant differences between the patients with positive and negative margins. Also, residual disease was associated with the menopausal status and age of the patients. Conclusion There is no optimal cone depth that is applicable for all patients. The most important predictors for positive margins are the menopausal status of the patient and that more than two quadrants are involved. However, the menopausal status and age of the patients were still predictors for residual disease.

  13. A Novel Surgical Technique for Thyroid Cancer with Intra-Cricotracheal Invasion: Windmill Resection and Tetris Reconstruction.

    PubMed

    Enomoto, Keisuke; Uchino, Shinya; Noguchi, Hitoshi; Enomoto, Yukie; Noguchi, Shiro

    2015-12-01

    The most effective treatment for thyroid cancer (TC) invading into the larynx and trachea is a complete surgical resection of the tumor, but currently employed techniques are less than ideal. We report a novel surgical technique, which we named Windmill resection and Tetris reconstruction, for patients with TC invading into the laryngeal lumen. We treated eight cases of TC with invasion into the laryngeal lumen by Windmill resection and Tetris reconstruction. We analyzed complications, clinical data, and pathological findings for all patients. Patients included one man and seven women (mean age 69 ± 10 years). Histopathology of TC indicated papillary cancer in five patients, poorly differentiated cancer in one patient, anaplastic cancer in one patient, and squamous cell carcinoma in one patient. Unilateral recurrent laryngeal nerve (RLN) palsy was confirmed preoperatively by laryngoscope in four patients, and none had bilateral RLN palsy. All patients underwent Windmill resection and Tetris reconstruction along with total thyroidectomy (three patients), subtotal thyroidectomy (three patients), and lobectomy (two patients). Neck dissection was performed in all patients. The average resected length of the larynx and trachea was 29 ± 6 mm. Air leakage at the suture line occurred in three patients; two required further surgery, while the third was closed by insertion of a Penrose drain. Postoperative RLN palsy occurred in five patients. Aspiration was observed in two patients and resolved within 4 weeks. Pneumonia, atelectasis, and pleural effusion occurred in some patients. No other complications, including hemorrhage, wound infection, or airway stenosis, occurred. There was no postoperative mortality and no recurrence at the anastomotic site. Two patients underwent permanent tracheostomy due to permanent bilateral RLN palsy. Two patients, one with anaplastic cancer and the other with poorly differentiated cancer, recurred 13 and 21 months after surgery

  14. Evaluation of coblation lingual tonsil removal technique for obstructive sleep apnea in Asians: preliminary results of surgical morbidity and prognosticators.

    PubMed

    Wee, Jee Hye; Tan, Kenglu; Lee, Woo-Hyun; Rhee, Chae-Seo; Kim, Jeong-Whun

    2015-09-01

    Retroglossal obstruction is one of the etiologies causing obstructive sleep apnea (OSA) and can be addressed by removing some tissues of the tongue base. However, because of its deep-seated location, its surgical removal is still challenging. Although coblation technique has been introduced, its efficacy and morbidity need further evaluation, particularly in Asians. This study aimed to assess its safety and effectiveness and to identify outcome prognosticators. Forty-seven OSA patients who underwent coblation lingual tonsil removal were included. Retroglossal obstruction was confirmed by drug-induced sleep videofluoroscopy. Attended full-night polysomnography was performed twice; before and 6 months after surgery in 27 patients. The tongue base was fully exposed with three deep-seated traction sutures, visualized with a 30° or 70° endoscope, and ablated using a coblator. Surgical success was defined with postoperative apnea hypopnea index (AHI) <20 and reduction >50 %. Postoperative morbidities were evaluated. Demographic and polysomnographic parameters between success and failure groups were compared. None of the patients had immediate postoperative hemorrhage. Postoperatively, one patient had delayed hemorrhage and one patient severe respiratory difficulty. Taste loss, tongue dysmotility, dental injury or severe oropharyngeal stricture were absent. A mean AHI decreased from 37.7 ± 18.6 to 18.7 ± 14.8/h (P < 0.001). The success rate was 55.6 %. Their mean minimal oxygen saturation was significantly lower (P = 0.004) in the failure group. Coblation lingual tonsil removal technique showed minimal morbidity and favorable outcome in Koreans. The surgical outcome might be associated with the severity of single respiratory events.

  15. Optimization of the extent of surgical treatment in patients with stage I in cervical cancer

    NASA Astrophysics Data System (ADS)

    Chernyshova, A. L.; Kolomiets, L. A.; Sinilkin, I. G.; Chernov, V. I.; Lyapunov, A. Yu.

    2016-08-01

    The study included 26 patients with FIGO stage Ia1-Ib1 cervical cancer who underwent fertility-sparing surgery (transabdominaltrachelectomy). To visualize sentinel lymph nodes, lymphoscintigraphy with injection of 99mTc-labelled nanocolloid was performed the day before surgery. Intraoperative identification of sentinel lymph nodes using hand-held gamma probe was carried out to determine the radioactive counts over the draining lymph node basin. The sentinel lymph node detection in cervical cancer patients contributes to the accurate clinical assessment of the pelvic lymph node status, precise staging of the disease and tailoring of surgical treatment to individual patient.

  16. The Future of Rheumatoid Arthritis and Hand Surgery - Combining Evolutionary Pharmacology and Surgical Technique

    PubMed Central

    M, Malahias; H, Gardner; S, Hindocha; A, Juma; Khan, W

    2012-01-01

    Rheumatoid arthritis is a systemic autoimmune disease of uncertain aetiology, which is characterized primarily by synovial inflammation with secondary skeletal destructions. Rheumatoid Arthritis is diagnosed by the presence of four of the seven diagnostic criteria, defined by The American College of Rheumatology. Approximately half a million adults in the United Kingdom suffer from rheumatoid arthritis with an age prevalence between the second and fourth decades of life; annually approximately 20,000 new cases are diagnosed. The management of Rheumatoid Arthritis is complex; in the initial phase of the disease it primarily depends on pharmacological management. With disease progression, surgical input to correct deformity comes to play an increasingly important role. The treatment of this condition is also intimately coupled with input from both the occupational therapists and physiotherapy. PMID:22423304

  17. Ex-PRESS mini glaucoma shunt: surgical technique and review of clinical experience.

    PubMed

    Hendrick, Andrew M; Kahook, Malik Y

    2008-11-01

    Glaucoma is a leading cause of worldwide blindness. Treatment of this chronic disease, centered on lowering intraocular pressure (IOP), may require surgical intervention when medical and/or laser therapy fail to control IOP. Traditional glaucoma surgery, such as trabeculectomy, has been performed for decades and has a proven track record of success. Unfortunately, many complications such as hypotony and slow visual recovery are known to occur and can lead to significant patient morbidity. New devices are being developed to allow surgeons increased control with more predictable postoperative results. One such device, the Ex-PRESS mini glaucoma shunt, has undergone changes in design and method of insertion making it more appealing for use in patients requiring IOP-lowering surgery. We summarize pertinent literature and expand on the future role of this device in glaucoma surgery. PMID:19025342

  18. Ulnar-basilic fistula: indications, surgical aspects, puncture technique, and results.

    PubMed

    Salgado, Octavio J; Chacón, Rosa E; Henríquez, Carlos

    2004-07-01

    Ulnar-basilic fistula (UBF) is an autogenic vascular access option for hemodialysis (HD) first reported in 1967. However, only a few reports dealing with its complications and survival rates have been published in the literature. In the present work the results of 61 UBFs done in 60 adult patients on chronic HD are reported. Forty UBFs were created as primary access and the remaining 21 UBF as secondary access after: (a) thrombosis of an ipsilateral radiocephalic fistula (RCF) in 6 cases, (b) thrombosis of a contralateral RCF in 7 cases, and (c) thrombosis of a brachiocephalic fistula in 2 cases. No episodes of surgical complications, arterial steal, or ulnar nerve damage were observed. Five UBFs thrombosed within the first week after surgery. The 1-, 3-, and 5-year unassisted survival rates were 70.9%, 67.7%, and 57.3%, respectively, which were significantly higher than those reported previously. The inclusion of UBF in routine access plans is recommended.

  19. Novel Endoscopic and Surgical Techniques for Treatment of Morbid Obesity: A Glimpse into the Future.

    PubMed

    Davis, Matthew; Kroh, Matthew

    2016-08-01

    The burden of obesity and weight-related comorbid disease is significant. Existing laparoscopic techniques show excellent efficacy and safety. New endoscopic and laparoscopic procedures offer different approaches, as primary and revisional techniques, to treat obesity and associated metabolic disease. PMID:27473806

  20. Nasogastric tube placement into the hepaticojejunostomy anastomosis in pancreaticoduodenectomy: a simple surgical technique for prevention of bile leak.

    PubMed

    Kaya, Bulent; Ozcabi, Yetkin; Tasdelen, Iksan; Onur, Ender; Memisoglu, Kemal

    2016-05-01

    Hepaticojejunostomy is an important part of many surgical procedures including pancreaticoduodenectomy. Biliary leakage from hepaticojejunostomy may be associated with intraabdominal abscess formation, biliary peritonitis, and even mortality. A 72-year-old female patient was admitted to our hospital with obstructive jaundice. After initial evaluation, she was diagnosed with distal common bile duct obstruction without accurate diagnosis. Before planned pancreaticoduodenectomy, biliary drainage with a T-tube was performed due to the presence of cholangitis. After the first operation, pancreaticoduodenectomy was performed. Postinflammatory changes around the hilar region made the hepaticojejunostomy risky. A bilio-digestive anastomosis was performed using a new technique. A nasogastric tube was placed into the common bile duct proximal to the anastomosis. The postoperative course of the patient was uneventful. The use of a nasogastric tube as a stent in risky hepaticojejunostomies is a simple technique that can be beneficial.

  1. Optimal Surgical Management of Severe Ischemic Mitral Regurgitation: To Repair or to Replace?

    PubMed Central

    Perrault, Louis P.; Moskowitz, Alan J.; Kron, Irving L.; Acker, Michael A.; Miller, Marissa A.; Horvath, Keith A.; Thourani, Vinod H.; Argenziano, Michael; D'Alessandro, David A.; Blackstone, Eugene H.; Moy, Claudia S.; Mathew, Joseph P.; Hung, Judy; Gardner, Timothy J.; Parides, Michael K.

    2013-01-01

    Background Ischemic mitral regurgitation (MR), a complication of myocardial infarction and coronary artery disease more generally, is associated with a high mortality rate and estimated to affect 2.8 million Americans. With 1-year mortality rates as high as 40%, recent practice guidelines of professional societies recommend repair or replacement, but there remains a lack of conclusive evidence supporting either intervention. The choice between therapeutic options is characterized by the trade-off between reduced operative morbidity and mortality with repair versus a better long-term correction of mitral insufficiency with replacement. The long-term benefits of repair versus replacement remain unknown, which has led to significant variation in surgical practice. Methods and Results This paper describes the design of a prospective randomized clinical trial to evaluate the safety and effectiveness of mitral valve repair and replacement in patients with severe ischemic mitral regurgitation. This trial is being conducted as part of the Cardiothoracic (CT) Surgical Trials Network. This paper addresses challenges in selecting a feasible primary endpoint, characterizing the target population (including the degree of MR), and analytical challenges in this high mortality disease. Conclusions The paper concludes by discussing the importance of information on functional status, survival, neurocognition, quality of life and cardiac physiology in therapeutic decision-making. PMID:22054660

  2. A new technique of subtrochanteric shortening in total hip arthroplasty: surgical technique and results of 9 cases.

    PubMed

    Bruce, W J; Rizkallah, S M; Kwon, Y M; Goldberg, J A; Walsh, W R

    2000-08-01

    Total hip arthroplasty for severe chronic proximal femoral migration, most commonly seen in congenital dislocation of the hip, has been associated with high rates of complications. A new technique of femoral subtrochanteric shortening osteotomy with the prosthesis in situ is described. This technique minimizes the potential complications, allows for correction of severe femoral neck anteversion, and gives excellent rotational stability, while preserving the proximal femur for better press-fit cementless fixation. In this series, there were 9 cases: 6 women and 2 men with a mean age of 53 years (range, 26-77 years). The average follow-up period was 56 months (range, 6-86 months). The mean preoperative Harris Hip Score was 31 (range, 20-35), and the mean postoperative score was 81 (range, 60-98). At follow-up, all patients reported significant pain relief and functional improvement. All osteotomies appeared to be healed on radiographs by 12 weeks. There were 3 complications. The first complication was a recurrent dislocation resulting from muscle incompetence, which was revised using a constrained liner and a 32-mm head with no further dislocations. The second complication was a breach of the femoral shaft, which was treated operatively using a longer stem. The third complication was a proximal femoral shaft split, which was treated by leaving the cerclage wire in situ. This technique should be considered in cases of congenital dislocation of the hip and when femoral shortening is needed. PMID:10960001

  3. Unilateral orchidectomy in donkey (Equus asinus): Evaluation of different surgical techniques, histological and morphological changes on remaining testis

    PubMed Central

    Mahmoud Ali Omar, Magda; Mohamed Ahmed Hassanein, Khaled; Khalifa Abdel-Razek, Abdel-Razek; Ali Yousef Hussein, Haroon

    2013-01-01

    Unilateral orchidectomy (UO) is required when further breeding potential is important. It is sometimes necessary to remove a single testis in a matured stallion for therapeutic reasons. In this study, twelve donkeys were used to evaluate three techniques of unilateral castration, histological and morphological changes on the remaining testis. Results of the study showed that each of the surgical techniques used had its advantages and disadvantages in comparison with the other two techniques. Therefore the selection among the three techniques depends on the surgeon preferences and the environment in which the unilateral orchidectomy is performed. The volume of the remaining testis recorded at the end of the study was significantly greater than that estimated at the start of the study (p < 0.05). The percentage of sperm motility obtained from the remaining testis was significantly decreased (p < 0.05). Histological examination of the testis in open surgery (group I) (where the scrotum was left opened) revealed severe hemorrhages, edema and fibrosis. The test is showed degenerative changes in the seminiferous tubules and interstitial orchitis. Histological examination of the testes removed using a closed technique, (in groups II and III) where the scrotum wound was sutured, revealed hyperplasia of spermatogenic series and Leydig cells. In conclusion, unilateral orchidectomy had compensatory effects on the weight and volume of remaining testis. Adverse effects on sperm motility and viability can affect the fertility of the animal. PMID:25593678

  4. Unilateral orchidectomy in donkey (Equus asinus): Evaluation of different surgical techniques, histological and morphological changes on remaining testis.

    PubMed

    Mahmoud Ali Omar, Magda; Mohamed Ahmed Hassanein, Khaled; Khalifa Abdel-Razek, Abdel-Razek; Ali Yousef Hussein, Haroon

    2013-01-01

    Unilateral orchidectomy (UO) is required when further breeding potential is important. It is sometimes necessary to remove a single testis in a matured stallion for therapeutic reasons. In this study, twelve donkeys were used to evaluate three techniques of unilateral castration, histological and morphological changes on the remaining testis. Results of the study showed that each of the surgical techniques used had its advantages and disadvantages in comparison with the other two techniques. Therefore the selection among the three techniques depends on the surgeon preferences and the environment in which the unilateral orchidectomy is performed. The volume of the remaining testis recorded at the end of the study was significantly greater than that estimated at the start of the study (p < 0.05). The percentage of sperm motility obtained from the remaining testis was significantly decreased (p < 0.05). Histological examination of the testis in open surgery (group I) (where the scrotum was left opened) revealed severe hemorrhages, edema and fibrosis. The test is showed degenerative changes in the seminiferous tubules and interstitial orchitis. Histological examination of the testes removed using a closed technique, (in groups II and III) where the scrotum wound was sutured, revealed hyperplasia of spermatogenic series and Leydig cells. In conclusion, unilateral orchidectomy had compensatory effects on the weight and volume of remaining testis. Adverse effects on sperm motility and viability can affect the fertility of the animal. PMID:25593678

  5. Influence of two different surgical techniques on the difficulty of impacted lower third molar extraction and their post-operative complications

    PubMed Central

    Ohanyan, Ani; Kechagias, Nikos; Tsekos, Antonis; Vahtsevanos, Konstantinos

    2015-01-01

    Background Post-operative complications of various degrees of severity are commonly observed in third molar impaction surgery. For this reason, a surgical procedure that decreases the trauma of bone and soft tissues should be a priority for surgeons. In the present study, we compare the efficacy and the post-operative complications of patients to whom two different surgical techniques were applied for impacted lower third molar extraction. Material and Methods Patients of the first group underwent the classical bur technique, while patients of the second group underwent another technique, in which an elevator was placed on the buccal surface of the impacted molar in order to luxate the alveolar socket more easily. Results Comparing the two techniques, we observed a statistically significant decrease in the duration of the procedure and in the need for tooth sectioning when applying the second surgical technique, while the post-operative complications were similar in the two groups. We also found a statistically significant lower incidence of lingual nerve lesions and only a slightly higher frequency of sharp mandibular bone irregularities in the second group, which however was not statistically significant. Conclusions The results of our study indicate that the surgical technique using an elevator on the buccal surface of the tooth seems to be a reliable method to extract impacted third molars safely, easily, quickly and with the minimum trauma to the surrounding tissues. Key words:Mandibular third molar, impacted, surgical technique, extraction, elevator. PMID:26116843

  6. Linear left atrial lesions in minimally invasive surgical ablation of persistent atrial fibrillation: techniques for assessing conduction block across surgical lesions.

    PubMed

    Lockwood, Deborah; Nakagawa, Hiroshi; Peyton, Marvin D; Edgerton, James R; Scherlag, Benjamin J; Sivaram, Chittur A; Po, Sunny S; Beckman, Karen J; Abedin, Moeen; Jackman, Warren M

    2009-12-01

    Minimally invasive surgical (MIS) ablation, with pulmonary vein (PV) isolation and ganglionated plexi (GP) ablation, has proven highly successful for paroxysmal atrial fibrillation but has limited success in patients with persistent and long-standing persistent (P-LSP) AF. A set of linear left atrial (LA) lesions has been added to interrupt some macroreentrant components of P-LSP AF. This includes a Transverse Roof Line and Left Fibrous Trigone Line (from Roof Line to mitral annulus at the left fibrous trigone). With complete conduction block (CCB), these lesions should prevent single- or double-loop macroreentrant LA tachycardias from propagating around the PVs or mitral annulus. It is critical to identify whether CCB has been achieved and, if not, to locate the gap for further ablation, since residual gaps will support macroreentrant atrial tachycardias. Confirming CCB involves pacing close to one side of the ablation line and determining the direction of activation on the opposite side, by recording close bipolar electrograms at multiple paired sites (perpendicular and close to the ablation line) along the entire length of the line. Simpler approaches have been used, but all have limitations, especially when the conduction time across a gap is long. The extended lesion set was created after PV isolation and GP ablation in 14 patients with P-LSP AF. Mapping after the first set of radiofrequency applications for the Transverse Roof and Left Trigone Lines confirmed CCB in only 3/14 (21%) patients for each line, showing the importance of checking for CCB. During follow-up (median 8 months), 10/14 (71%) patients had no symptoms of atrial arrhythmia (7/10 off antiarrhythmic drugs). Of the remaining four patients, three have only infrequent episodes (self-terminating in 2/3). These preliminary results suggest that adding Roof and Trigone Lines may increase MIS success in patients with P-LSP AF. Accurate mapping techniques verify CCB and effectively locate gaps in

  7. A simple, safe, and effective surgical technique for the treatment of post-traumatic parotid sialocoele.

    PubMed

    Asha'ari, Zamzil Amin; Razali, Mohd Sayuti; Leman, Wan Ishlah; Ahmad, Ashri

    2014-01-01

    Post-traumatic parotid sialocoele is a subcutaneous extravasation of saliva from the parotid gland secondary to traumatic disruption of its duct or parenchyma. Currently, there is no consensus regarding the best therapy for parotid sialocoele, as it is resistant to conservative management. The present paper puts forward a relatively simple, safe and effective technique for the treatment of parotid sialocoele, specifically a peroral drainage technique. The results justify our recommendation to use this approach for the treatment of sialocoele.

  8. Submucosal anoderm-preserving hemorrhoidectomy revisited: a modified technique for the surgical management of hemorrhoidal crisis.

    PubMed

    Theodoropoulos, George E; Michalopoulos, Nikolaos V; Linardoutsos, Dimitrios; Flessas, Ioannis; Tsamis, Dimitrios; Zografos, George

    2013-11-01

    Submucosal hemorrhoidectomy (Parks' procedure) is a recognized method for treating acute hemorrhoidal crisis. Anoderm preservation has been stressed in various techniques described for elective or emergency excisional hemorrhoidal management. Mucopexy techniques have been proven useful as an adjunct to minimally resectional techniques. A modified submucosal technique with anoderm preservation and mucopexy was applied to 45 patients who presented on an emergency basis with hemorrhoidal crisis. External piles were minimally removed, the minimum possible amount of diseased mucosa was excised, a linear incision was used at the anoderm to enter the subanodermal/mucosal plane to achieve the submucosal excision, and a mucopexy was added at the approximation of the mucosal flaps. Postoperative morbidity was minimal and pain after the procedure remained at acceptable levels. This technique allows for an excision limited to the pathology with important anatomic tissue preservation. This results in conservation of the sensitive and useful anoderm, a decreased risk of stenosis, and addresses the mucosal prolapse. The level of postoperative pain with this technique is acceptable and long-term follow-up reveals a high degree of patient satisfaction.

  9. “The Superficial Quad Technique” for Medial Patellofemoral Ligament Reconstruction: The Surgical Video Technique

    PubMed Central

    Goyal, Deepak

    2015-01-01

    With the introduction of the superficial quad technique, there has been a recent revival of interest in the quadriceps tendon as a graft choice for medial patellofemoral ligament (MPFL) reconstruction. The superficial quad technique has many anatomic advantages because the length, breadth, and thickness of the graft are similar to those of the native MPFL; moreover, the graft provides a continuous patellar attachment at the superior half of the medial border of the patella. The technique requires neither a patellar bony procedure nor patellar hardware. Biomechanically, the mean strength and stiffness of the graft are very similar to those of the native MPFL. The anatomic and biomechanical advantages depend on correct identification of the anatomic superficial lamina of the quadriceps tendon; hence the correct harvesting technique for the superficial lamina is crucial. Various sub-techniques for harvesting the quadriceps graft have emerged recently, such as superficial strip, pedicled, or partial graft harvesting; these can create confusion for surgeons. Additional confusion related to the preparation and fixation of the graft should also be addressed to avoid any potential complications. A step-by-step video of the superficial quad technique is presented, covering the exact dissection of the graft material and its preparation, delivery, and fixation. PMID:26900556

  10. Obturator hernia revisited: surgical anatomy, embryology, diagnosis, and technique of repair.

    PubMed

    Stamatiou, Dimitrios; Skandalakis, Lee J; Zoras, Odysseas; Mirilas, Petros

    2011-09-01

    Obturator hernia is the protrusion of intraperitoneal or extraperitoneal organs or tissues through the obturator canal. The first case was published by de Ronsil in 1724. Obturator hernia is more common in older malnourished women due to loss of supporting connective tissue and the wider female pelvis. The hernia sac usually contains small bowel, especially ileum. It may follow the anterior or posterior division of the obturator nerve. In most cases, obturator hernia presents with intestinal obstruction of unknown cause. It may present with obturator neuralgia, as a palpable mass or, in cases of bowel necrosis, as ecchymosis of the thigh. A correct diagnosis is made in 20 to 30 per cent of cases. CT scan is considered the gold standard for diagnosis, whereas ultrasonography, contrast studies, herniography and plain films are less specific. Surgery is the only treatment option for obturator hernia. Hesitancy to intervene surgically for chronically ill patients results in high mortality. Transabdominal approach is indicated in cases of complete bowel obstruction or suspected peritonitis. The extra-abdominal approach is used in preoperatively diagnosed cases and in absence of bowel strangulation. The laparoscopic approach is minimally invasive and effectively reduces morbidity. The defect is closed using sutures, tissue flaps, or prosthetic mesh.

  11. Arthroscopic contact Nd:YAG laser meniscectomy: basic science, surgical technique, and clinical follow up

    NASA Astrophysics Data System (ADS)

    O'Brien, Stephen J.; Fealy, Stephen V.; Gibney, Mary A.; Miller, Drew V.; Kelly, Anne M.

    1990-06-01

    Recent basic science studies (5) have provided a scientific foundation for the use of the Contact Nd:YAG Laser as an arthroscopic tool for xneniscal resection and acroxnioplasty of the shoulder in a saline medium. This study prospectively evaluates the results of a three stage laboratory investigation as well as the clinical results of arthroscopic xneniscal resection. Fifteen patients with meniscal tears underwent subtotal meniscectomies utilizing a Contact Nd:YAG Laser (Surgical Laser Technologies; Malvern, Pennsylvania) . This was done in a saline medium with an average laser wattage of 25 W, (range 20 W to 30 W). Patients were evaluated postoperatively with reference to subjective and objective parameters at one week and four weeks postoperatively. Patients were evaluated with regard to wound healing, intraarticular swelling and pain. Assessment of technical parameters such as ease of resection, time of resection and instrument access were compared to conventional instruments. All fifteen patients were rated as having clinically excellent results based on pain relief, wound healing and swelling. In addition, although there was increased time with setting up the laser and calibrating it, there was not an increase in time for meniscal resection. Little, or no, secondary "trimmuning" was necessary with the laser. Increased accessibility was noted due to the small size of the laser. Arthroscopic Contact Nd:YAG Laser surgery is a safe and effective tool for menisca]. resection and coagulation in arthroscopic acromioplasties. It provides significant advantages over conventional cutting instruments with regard to accessibility and reduced need for secondary instruments.

  12. The clinical study of the optimalization of surgical treatment and the traditional Chinese medicine intervention on palmar hyperhidrosis.

    PubMed

    Yang, Yong; Yan, Zhikun; Fu, Xiaoqing; Dong, Liwen; Xu, Linhai; Wang, Jun; Cheng, Genmiao

    2014-11-01

    To analyze the efficacy of different surgical methods in treating palmar hyperhidrosis and the compensatory hyperhidrosis after surgery and to observe the efficacy of "Energy-boosting and Yin-nourishing anti-perspirant formula" on postsurgical hyperhidrosis patients. Two-hundred patients were randomly assigned to groups A (Chinese and Western medicine, T4 transection plus "Energy-boosting and Yin-nourishing anti-perspirant formula") and B (Western medicine, T4 transection). The surgical efficiency, recurrence rate, compensatory hyperhidrosis, and the long-term life quality were compared. Another 100 cases (group C, T2 transection) were analyzed as a control group. After surgery, the palmar hyperhidrosis and armpit sweating were relieved in all the three group patients and in 34 % of patients combined with plantar hyperhidrosis, the symptoms were relieved. Transient palmar hyperhidrosis was found in three cases at day 2 to day 5 postoperatively. One case of Horner's syndrome and one case recurrence were found in group C patients. The compensatory sweating of various degrees occurred in all the three groups. There were 25, 24, and 43 cases in groups A, B, and C, respectively. There is a significant difference between groups C, A, and B. The compensatory sweating in 13 cases of group A and four cases of group B had different degrees of improvement in the follow-up 6 months after surgery. There is a significant difference. Thoracoscopic bilateral T4 sympathetic chain and the Kuntz resection are the optimized surgical treatments for the palmar hyperhidrosis. "Energy-boosting and Yin-nourishing anti-perspirant formula" is effective in treating the postoperative compensatory sweating.

  13. [Two Surgical Techniques for Metastatic Brain Tumors:Minimum Resection and Removal with Safety Margin].

    PubMed

    Nakasu, Yoko; Mitsuya, Koichi; Hayashi, Nakamasa; Ito, Ichiro

    2016-03-01

    Successful resection of cerebral metastases is based on good basic neurosurgical techniques, in conjunction with technologies for tumor localization. A clear understanding about the border zone pathology of metastatic lesions leads to two different techniques for safe and effective tumor removal. There is no capsule or pseudocapsule around the metastatic brain tumors. The border zone is widely heterogeneous, especially in lesions after stereotactic irradiation. Resection can be performed in a circumferential and en bloc fashion with sufficient safety margin of the normal brain in non-eloquent area. However, enucleation should be done without surrounding brain damage in and near eloquent areas.

  14. A modified surgical technique for lengthening of a metatarsal using an external fixator.

    PubMed

    Scher, David M; Blyakher, Arkady; Krantzow, Michael

    2010-09-01

    Brachymetatarsia is a congenital or developmental condition that results in a short metatarsal. Problems that arise from this condition can include pain, difficulty with shoe wear, and cosmetic concerns. Multiple techniques have been described that successfully correct the deformity, including both acute and gradual distraction. We describe a modification of the technique of gradual lengthening by way of distraction osteogenesis in which an axial transarticular K-wire is incorporated into a monolateral frame, thereby increasing the stability of the construct and potentially minimizing complications. PMID:21886542

  15. A Modified Surgical Technique for Lengthening of a Metatarsal Using an External Fixator

    PubMed Central

    Blyakher, Arkady; Krantzow, Michael

    2010-01-01

    Brachymetatarsia is a congenital or developmental condition that results in a short metatarsal. Problems that arise from this condition can include pain, difficulty with shoe wear, and cosmetic concerns. Multiple techniques have been described that successfully correct the deformity, including both acute and gradual distraction. We describe a modification of the technique of gradual lengthening by way of distraction osteogenesis in which an axial transarticular K-wire is incorporated into a monolateral frame, thereby increasing the stability of the construct and potentially minimizing complications. PMID:21886542

  16. Investigation into the optimal surgical conditions for coronary artery ligation for establishing a myocardial infarction model in mice

    PubMed Central

    YUE, XIA; YU, HONGSHENG; LIN, XIALU; LIU, KUI; WANG, XIN; ZHOU, FEI; ZHAO, JINSHUN; ZOU, BAOBO

    2013-01-01

    In the present study, the left anterior descending coronary arteries of mice under anesthesia were ligated, and the optimal surgical conditions for coronary artery ligation (CAL) in the establishment of a myocardial infarction (MI) mouse model were investigated. All mice that survived were sacrificed seven days subsequent to the successful surgery. Body weight, blood serum and heart tissues were obtained for further analysis or biochemical and histopathological examinations. The survival rate of the mice following the CAL procedure was 70%. The aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) concentrations in the serum of the experimental mice were significantly increased compared with those of the control mice, which reflected the enzyme release from the infarcted myocardial cells. Histopathological examination showed different degrees of MI in the heart tissues of the experimental mice. The results indicate that an MI model in mice may be successfully established using CAL under the surgical conditions utilized in the present study. These conditions were cost effective and the results may be replicated by laboratories that are less well-equipped. PMID:24137186

  17. Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management.

    PubMed

    Wolfe, J Alan; Malaisrie, S Chris; Farivar, R Saeid; Khan, Junaid H; Hargrove, W Clark; Moront, Michael G; Ryan, William H; Ailawadi, Gorav; Agnihotri, Arvind K; Hummel, Brian W; Fayers, Trevor M; Grossi, Eugene A; Guy, T Sloane; Lehr, Eric J; Mehall, John R; Murphy, Douglas A; Rodriguez, Evelio; Salemi, Arash; Segurola, Romualdo J; Shemin, Richard J; Smith, J Michael; Smith, Robert L; Weldner, Paul W; Lewis, Clifton T P; Barnhart, Glenn R; Goldman, Scott M

    2016-01-01

    Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery. PMID:27654406

  18. Hamate hook nonunion treated with a hook plate: case report and surgical technique.

    PubMed

    Taleb, Chihab; Murachowsky, Joel; Ruggiero, Gustavo M

    2012-12-01

    Despite of its rarity, hamate hook nonunion can cause several complications like tendon rupture or loss of grip strength. Admitted treatments in the literature are excision of the bone fragment or its open reduction and internal fixation. We report a clinical case of a high-level baseball player with hamate hook nonunion treated with an original technique of fixation using a hook plate.

  19. New technique for treating abdominal surgical site infection using CT woundgraphy and NPWT: A case report

    PubMed Central

    Ito, Eisaku; Yoshida, Masashi; Nakashima, Keigo; Suzuki, Norihiko; Imakita, Tomonori; Tsutsui, Nobuhiro; Ohdaira, Hironori; Kitajima, Masaki; Suzuki, Yutaka

    2016-01-01

    Introduction Negative pressure wound therapy (NPWT) for abdominal surgical site infection (SSI) is becoming increasingly common, although enterocutaneous fistula (ECF) has been reported as a complication. To avoid ECF, we used computed tomography (CT) woundgraphy to evaluate the relationship between the wound and the intestine, and then safely treated the abdominal SSI with NPWT. Case presentation Following a laparoscopic intersphincteric resection for low rectal neuroendocrine tumor and covering ileostomy, a 59-year-old woman underwent stoma closure. Six days after surgery, we diagnosed SSI. We suspected ECF, because the wound was deep and the pus resembled enteric fluid. However, CT woundgraphy showed that the wound was separated from the abdominal cavity and the intestine by the abdominal rectus muscle. Accordingly, we performed NPWT. SSI was cured and the wound was well granulated. Twenty-three days after surgery, the patient was discharged. Eventually, the wound was completely epithelialized. Discussion Although successful NPWT has been reported for open abdominal wounds, ECF is a common complication. ECF can be prevented by separating the wound from the intestine by the omentum or muscle fascia, protecting the intestinal serosa during surgery, and applying low vacuum pressure. The relationships among the wound, the fascia, and the intestine must be evaluated before abdominal SSI treatment. One good method is CT woundgraphy, which evaluates wound extent and depth, closure of muscle fascia, and the relationship between the wound and the intestine. Conclusion We report a case of CT woundgraphy before NPWT for abdominal SSI. CT woundgraphy is a good candidate for evaluating wound condition. PMID:27002290

  20. Challenging the Surgical Rodent Hindlimb Ischemia Model with the Miniinterventional Technique

    PubMed Central

    Zhuang, Zhen W.; Shi, Jing; Rhodes, John M.; Tsapakos, Michael J.; Simons, Michael

    2012-01-01

    Purpose To develop an interventional hindlimb ischemic model and compare its angiogenic effect versus surgical ligation (SL) and excision of the femoral artery in rats treated with transplantation of bone marrow mononuclear cells (MNCs) as an angiogenic stimulator. Materials and Methods Forty-eight Lewis rats randomly received interventional embolization (IE) with hydrogel wire or SL and excision of the right femoral artery. Rodents were intraarterially transplanted with 1.5 × 107 MNCs in 500 μL medium from 24 isogenic donor rats. Functional and structural recovery was evaluated by laser Doppler imaging (LDI), cytokine/chemokine assay, and histologic staining. Results In vivo microscopic images showed significantly dilated vasa vasorum around the embolized segment of the right femoral artery at 3 days compared with disorganized tissue structure in the SL group. However, the LDI index was significantly higher in the SL group at 3 days compared with the IE group. LDI did not significantly differ between the two groups at 2 weeks after transplantation. Cytokine assay showed higher levels of interleukin (IL)–1α and IL-18 in the SL group; the IE group had higher levels of interferon-γ, IL-6, IL-13, and granulocyte colony-stimulating factor. Histologic examination demonstrated inflammatory infiltration near the incision within nerve fibers with dilated capillaries, showing nerve degeneration in the SL group. At 2 weeks, histologic analysis demonstrated massive scarring under the skin spreading into the musculature in the SL group. Conclusions A minimally invasive hindlimb ischemia model has been successfully developed that preserves tissue integrity and minimizes inflammation and confounding factors in the early stages of angiogenesis and arteriogenesis. PMID:21459613

  1. Arthroscopic Labrum Reconstruction in the Hip Using the Indirect Head of Rectus Femoris as a Local Graft: Surgical Technique.

    PubMed

    Sharfman, Zachary T; Amar, Eyal; Sampson, Thomas; Rath, Ehud

    2016-04-01

    The importance of the acetabular labrum has been well documented for the health and function of the hip joint. Labral reconstruction has proven effective but often requires the use of a cadaveric allograft or auto graft from the fascia lata or gracilis. The indirect head of the rectus femoris is in close proximity with the anterior superior acetabulum, which is the most common site of labral tears. Using the indirect head of the rectus femoris as a local graft minimizes surgical invasiveness by mitigating the need to harvest the graft from a different location, in case of an autograft, and by minimizing donor site morbidity and damage to local tissues. The graft is harvested and fixed to the acetabular rim through the same arthroscopic portals. Hip labral reconstruction using the reflected head of the rectus femoris tendon is a minimally invasive surgical procedure that restores stability to the hip joint, is applicable in all patients undergoing hip labral reconstruction, and offers decreased tissue morbidity compared with other grafting techniques. PMID:27462534

  2. Optimization techniques in molecular structure and function elucidation.

    PubMed

    Sahinidis, Nikolaos V

    2009-12-01

    This paper discusses recent optimization approaches to the protein side-chain prediction problem, protein structural alignment, and molecular structure determination from X-ray diffraction measurements. The machinery employed to solve these problems has included algorithms from linear programming, dynamic programming, combinatorial optimization, and mixed-integer nonlinear programming. Many of these problems are purely continuous in nature. Yet, to this date, they have been approached mostly via combinatorial optimization algorithms that are applied to discrete approximations. The main purpose of the paper is to offer an introduction and motivate further systems approaches to these problems. PMID:20160866

  3. Surgical reconstruction of PIP joint collateral ligament in chronic instability in a high performance athlete: case report and description of technique.

    PubMed

    Mantovani, Gustavo; Pavan, Alexandre; Aita, Marcio A; Argintar, Evan

    2011-06-01

    We present a case report describing the surgical technique for the reconstruction of the proximal interphalangeal (PIP) joint collateral ligament using autograft palmaris longus tendon graft. We accomplished this successfully in a high performance professional athlete presenting with chronic instability of the PIP joint. Our surgical reconstructive technique recreated anatomic ligament position, while correcting multidirectional instability without disruption of the other dynamic anatomic structures of the PIP joint. Our results demonstrated excellent clinical and functional results, and we offer our technique as an alternative to tenodesis procedures for individuals with professions that demand PIP motion.

  4. Shoulder arthroplasty in osteoarthritis: current concepts in biomechanics and surgical technique

    PubMed Central

    Merolla, G; Nastrucci, G; Porcellini, G

    Shoulder arthroplasty is a technically demanding procedure to restore shoulder function in patients with severe osteoarthritis of the glenohumeral joint. The modern prosthetic system exploit the benefits of modularity and the availibility of additional sizes of the prosthetic components. In this paper we describe the biomechanics of shoulder arthroplasty and the technique for shoulder replacement including total shoulder arthroplasty (TSA) with all-polyethylene and metal-backed glenoid component, humeral head resurfacing and stemless humeral replacement. PMID:24251240

  5. Lateral high abdominal ovariopexy: an original surgical technique for protection of the ovaries during curative radiotherapy for Hodgkin's disease

    SciTech Connect

    Gaetini, A.; De Simone, M.; Urgesi, A.; Levis, A.; Resegotti, A.; Ragona, R.; Anglesio, S.

    1988-09-01

    An original surgical method for gonadal protection in young women given pelvic radiation for Hodgkin's disease is presented. Lateral high ovarian transposition (LHAO) consists of the transposition of the ovaries into the paracolic gutter during staging laparotomy, after disconnecting the gonads from the fallopian tubes by dividing the tubo-ovarian vessels. The technique's effectiveness was assessed by a study using clinical investigation, radioimmunoassay (RIA) determination of sex hormones, and dosimetry; of 18 patients treated, 10 participated in the study. All but one have normal menses and hormone values, and one pregnancy occurred. We also calculated the doses absorbed by the ovaries and proved that, during inverted Y irradiation following LHAO, the ovaries are exposed to nearly one-half the dose they receive after traditional medial transposition. During subtotal nodal irradiation after LHAO, the irradiation dose is higher than after medialisation, but absolute values are minimal and castration is not induced.

  6. Surgical repair of distal arch psendoaneurysm from ruptured penetrating aortic ulcer with the frozen elephant trunk technique.

    PubMed

    Kokotsakis, John; Tassopoulos, Dimitrios; Ttofi, Jacob; Harling, Leanne; Ashrafian, Hutan; Velissarios, Konstantinos; Kratimenos, Theodore; Anagnostou, Stratos; Athanasiou, Thanos

    2014-04-05

    Ruptured Penetrating Ulcer and aortic arch pseudo-aneurysm is a rare condition but one which carries a high risk of rupture. We report the case of a 74-year-old man with aortic arch pseudo-aneurysm, in which a Frozen Elephant Trunk procedure was successfully performed. There were no postoperative complications at 6 months follow-up. The Computed Tomography Angiogram demonstrated thrombus formation in the pseudo-aneurysm lumen, with no endoleak on the stented part of the descending thoracic aorta and complete patency of all branches of aortic arch. This case demonstrates that the Frozen Elephant Trunk technique may be the treatment of choice when treating such complex aortic arch lesions provided there is no absolute contraindication to radical surgical intervention. However, long-term clinical efficacy and safety have yet to be confirmed.

  7. Central Breast Excision With Immediate Autologous Reconstruction for Recurrent Periductal Sepsis: An Application of Oncoplastic Surgical Techniques

    PubMed Central

    Gore, Sinclair M.; Wishart, Gordon C.; Malata, Charles M.

    2012-01-01

    Objective: The aim of this procedure was to definitively treat periductal mastitis and periareolar sepsis which was previously resistant to multiple surgical procedures and nonoperative treatment of chronic nipple sepsis. Methods: We employed a multidisciplinary approach to the treatment of end-stage periductal mastitis using a combination of central breast excision and immediate autologous latissimus dorsi flap reconstruction. Results: Clearance of periductal mastitis and infection has been achieved with no recurrence at 3 years. Good symmetry of breast shape and volume has been achieved using this technique. Conclusions: This method of partial breast reconstruction, commonly used for reconstruction of breast cancer ablative defects, may also provide good outcomes in nonmalignant disease. PMID:22893784

  8. Vascular surgery trainees still need to learn how to sew: importance of learning surgical techniques in the era of endovascular surgery.

    PubMed

    Aziz, Faisal

    2015-01-01

    Vascular surgery represents one of the most rapidly evolving specialties in the field of surgery. It was merely 100 years ago when Dr. Alexis Carrel described vascular anastomosis. Over the course of next several decades, vascular surgeons distinguished themselves from general surgeons by horning the techniques of vascular surgery operations. In the era of minimally invasive interventions, the number of endovascular interventions performed by vascular surgeons has increased exponentially. Vascular surgery trainees in the current times spend considerable time in mastering the techniques of endovascular operations. Unfortunately, the reduction in number of open surgical operations has lead to concerns in regards to adequacy of learning open surgical techniques. In future, majority of vascular interventions will be done with minimally invasive techniques. Combination of poor training in open operations and increasing complexity of open surgical operations may lead to poor surgical outcomes. It is the need of the hour for vascular surgery trainees to realize the importance of learning and mastering open surgical techniques. One of the most distinguishing features of contemporary vascular surgeons is their ability to perform both endovascular and open vascular surgery operations, and we should strive to maintain our excellence in both of these arenas.

  9. Vascular Surgery Trainees Still Need to Learn How to Sew: Importance of Learning Surgical Techniques in the Era of Endovascular Surgery

    PubMed Central

    Aziz, Faisal

    2015-01-01

    Vascular surgery represents one of the most rapidly evolving specialties in the field of surgery. It was merely 100 years ago when Dr. Alexis Carrel described vascular anastomosis. Over the course of next several decades, vascular surgeons distinguished themselves from general surgeons by horning the techniques of vascular surgery operations. In the era of minimally invasive interventions, the number of endovascular interventions performed by vascular surgeons has increased exponentially. Vascular surgery trainees in the current times spend considerable time in mastering the techniques of endovascular operations. Unfortunately, the reduction in number of open surgical operations has lead to concerns in regards to adequacy of learning open surgical techniques. In future, majority of vascular interventions will be done with minimally invasive techniques. Combination of poor training in open operations and increasing complexity of open surgical operations may lead to poor surgical outcomes. It is the need of the hour for vascular surgery trainees to realize the importance of learning and mastering open surgical techniques. One of the most distinguishing features of contemporary vascular surgeons is their ability to perform both endovascular and open vascular surgery operations, and we should strive to maintain our excellence in both of these arenas. PMID:26029698

  10. Vascular surgery trainees still need to learn how to sew: importance of learning surgical techniques in the era of endovascular surgery.

    PubMed

    Aziz, Faisal

    2015-01-01

    Vascular surgery represents one of the most rapidly evolving specialties in the field of surgery. It was merely 100 years ago when Dr. Alexis Carrel described vascular anastomosis. Over the course of next several decades, vascular surgeons distinguished themselves from general surgeons by horning the techniques of vascular surgery operations. In the era of minimally invasive interventions, the number of endovascular interventions performed by vascular surgeons has increased exponentially. Vascular surgery trainees in the current times spend considerable time in mastering the techniques of endovascular operations. Unfortunately, the reduction in number of open surgical operations has lead to concerns in regards to adequacy of learning open surgical techniques. In future, majority of vascular interventions will be done with minimally invasive techniques. Combination of poor training in open operations and increasing complexity of open surgical operations may lead to poor surgical outcomes. It is the need of the hour for vascular surgery trainees to realize the importance of learning and mastering open surgical techniques. One of the most distinguishing features of contemporary vascular surgeons is their ability to perform both endovascular and open vascular surgery operations, and we should strive to maintain our excellence in both of these arenas. PMID:26029698

  11. Implementation of a Surgical Safety Checklist: Interventions to Optimize the Process and Hints to Increase Compliance

    PubMed Central

    Sendlhofer, Gerald; Mosbacher, Nina; Karina, Leitgeb; Kober, Brigitte; Jantscher, Lydia; Berghold, Andrea; Pregartner, Gudrun; Brunner, Gernot; Kamolz, Lars Peter

    2015-01-01

    Background A surgical safety checklist (SSC) was implemented and routinely evaluated within our hospital. The purpose of this study was to analyze compliance, knowledge of and satisfaction with the SSC to determine further improvements. Methods The implementation of the SSC was observed in a pilot unit. After roll-out into each operating theater, compliance with the SSC was routinely measured. To assess subjective and objective knowledge, as well as satisfaction with the SSC implementation, an online survey (N = 891) was performed. Results During two test runs in a piloting unit, 305 operations were observed, 175 in test run 1 and 130 in test run 2. The SSC was used in 77.1% of all operations in test run 1 and in 99.2% in test run 2. Within used SSCs, completion rates were 36.3% in test run 1 and 1.6% in test run 2. After roll-out, three unannounced audits took place and showed that the SSC was used in 95.3%, 91.9% and 89.9%. Within used SSCs, completion rates decreased from 81.7% to 60.6% and 53.2%. In 2014, 164 (18.4%) operating team members responded to the online survey, 160 of which were included in the analysis. 146 (91.3%) consultants and nursing staff reported to use the SSC regularly in daily routine. Conclusion These data show that the implementation of new tools such as the adapted WHO SSC needs constant supervision and instruction until it becomes self-evident and accepted. Further efforts, consisting mainly of hands-on leadership and training are necessary. PMID:25658317

  12. Optimizing Basic French Skills Utilizing Multiple Teaching Techniques.

    ERIC Educational Resources Information Center

    Skala, Carol

    This action research project examined the impact of foreign language teaching techniques on the language acquisition and retention of 19 secondary level French I students, focusing on student perceptions of the effectiveness and ease of four teaching techniques: total physical response, total physical response storytelling, literature approach,…

  13. Dynamic medial patellofemoral ligament reconstruction in recurrent patellar instability: A surgical technique

    PubMed Central

    Kiran, Kopuri Ravi; Srikanth, I Muni; Chinnusamy, Lenin; Deepti, K

    2015-01-01

    The medial patellofemoral ligament (MPFL) is the primary stabilizer of the patellofemoral joint; its reconstruction has been recommended in adults over the past decade after recurrent patellar instability. However, there has been no standardized technique for reconstruction, therefore, ideal graft and technique for reconstruction are yet undetermined. However, dynamic MPFL reconstruction studies claim to be superior to other procedures as it is more anatomical. This preliminary study aims at assessing the outcomes of MPFL reconstruction in a dynamic pattern using hamstring graft. We performed this procedure in four consecutive patients with chronic patellar instability following trauma. MPFL reconstruction was done with hamstring tendons detached distally and secured to patellar periosteum after being passed through a bony tunnel in the patella without an implant and using the medial collateral ligament as a pulley. In all 4 knees, the MPFL reconstruction was isolated and was not associated with any other realignment procedures. No recurrent episodes of dislocation or subluxation were reported at 24 months followup. PMID:26806970

  14. Practical light embalming technique for use in the surgical fresh tissue dissection laboratory.

    PubMed

    Anderson, Stephen D

    2006-01-01

    Surgeons using a fresh tissue dissection laboratory need specimens with tissue color and texture as close as possible to those of a living body. Completely unembalmed specimens kept in a cooler remain in good condition only for a few days, and then decay rapidly. Unembalmed specimens can be frozen for later use, but freezing harms their texture, and decay is suspended only for as long as they remain frozen. Since 1998, we have used a method of light embalming adapted from funeral home techniques, on over 250 cadavers used in our fresh tissue dissection laboratory. Lightly embalmed cadavers can be kept in a cooler for up to 6 weeks before use, with negligible loss of tissue quality and color. Once dissection is begun, the cadavers remain in excellent condition, free from odor, for at least two further weeks. Light embalming overcomes the practical problems seen with completely unembalmed specimens, avoids the use of freezing, and extends the range of activities that can be planned in the laboratory. This paper presents details of the light embalming technique. We assume that light embalming does not kill all transmissible pathogens.

  15. Acetabular protrusio: surgical technique of dealing with a problem in depth.

    PubMed

    Mullaji, A B; Shetty, G M

    2013-11-01

    There are few reports describing the technique of managing acetabular protrusio in primary total hip replacement. Most are small series with different methods of addressing the challenges of significant medial and proximal migration of the joint centre, deficient medial bone and reduced peripheral bony support to the acetabular component. We describe our technique and the clinical and radiological outcome of using impacted morsellised autograft with a porous-coated cementless cup in 30 primary THRs with mild (n = 8), moderate (n = 10) and severe (n = 12) grades of acetabular protrusio. The mean Harris hip score had improved from 52 pre-operatively to 85 at a mean follow-up of 4.2 years (2 to 10). At final follow-up, 27 hips (90%) had a good or excellent result, two (7%) had a fair result and one (3%) had a poor result. All bone grafts had united by the sixth post-operative month and none of the hips showed any radiological evidence of recurrence of protrusio, osteolysis or loosening. By using impacted morsellised autograft and cementless acetabular components it was possible to achieve restoration of hip mechanics, provide a biological solution to bone deficiency and ensure long-term fixation without recurrence in arthritic hips with protrusio undergoing THR. PMID:24187349

  16. Adjoint Techniques for Topology Optimization of Structures Under Damage Conditions

    NASA Technical Reports Server (NTRS)

    Akgun, Mehmet A.; Haftka, Raphael T.

    2000-01-01

    The objective of this cooperative agreement was to seek computationally efficient ways to optimize aerospace structures subject to damage tolerance criteria. Optimization was to involve sizing as well as topology optimization. The work was done in collaboration with Steve Scotti, Chauncey Wu and Joanne Walsh at the NASA Langley Research Center. Computation of constraint sensitivity is normally the most time-consuming step of an optimization procedure. The cooperative work first focused on this issue and implemented the adjoint method of sensitivity computation (Haftka and Gurdal, 1992) in an optimization code (runstream) written in Engineering Analysis Language (EAL). The method was implemented both for bar and plate elements including buckling sensitivity for the latter. Lumping of constraints was investigated as a means to reduce the computational cost. Adjoint sensitivity computation was developed and implemented for lumped stress and buckling constraints. Cost of the direct method and the adjoint method was compared for various structures with and without lumping. The results were reported in two papers (Akgun et al., 1998a and 1999). It is desirable to optimize topology of an aerospace structure subject to a large number of damage scenarios so that a damage tolerant structure is obtained. Including damage scenarios in the design procedure is critical in order to avoid large mass penalties at later stages (Haftka et al., 1983). A common method for topology optimization is that of compliance minimization (Bendsoe, 1995) which has not been used for damage tolerant design. In the present work, topology optimization is treated as a conventional problem aiming to minimize the weight subject to stress constraints. Multiple damage configurations (scenarios) are considered. Each configuration has its own structural stiffness matrix and, normally, requires factoring of the matrix and solution of the system of equations. Damage that is expected to be tolerated is local

  17. Cluster LEDs mixing optimization by lens design techniques.

    PubMed

    Chien, Ming-Chin; Tien, Chung-Hao

    2011-07-01

    This paper presents a methodology analogous to a general lens design rule to optimize step-by-step the spectral power distribution of a white-light LED cluster with the highest possible color rendering and efficiency in a defined range of color temperatures. By examining a platform composed of four single-color LEDs and a phosphor-converted cool-white (CW) LED, we successfully validate the proposed algorithm and suggest the optimal operation range (correlated color temperature = 2600-8500 K) accompanied by a high color quality scale (CQS > 80 points) as well as high luminous efficiency (97% of cluster's theoretical maximum value).

  18. Assessment of scapular morphology and surgical technique as predictors of notching in reverse shoulder arthroplasty.

    PubMed

    Sabesan, Vani; Callanan, Mark; Sharma, Vinay; Wiater, J Michael

    2015-05-01

    There has been increased focus on understanding risk factors for scapular notching in reverse shoulder arthroplasty (RSA). We conducted a study to evaluate the scapular notching index and other factors associated with the occurrence of scapular notching. Ninety-one patients treated with primary RSA were followed for a minimum of 24 months. Patients' radiographic assessments were grouped by Nerot grade of scapular notching (group 1, grades 0 and 1; group 2, grades 2, 3, 4). Group mean differences were compared for preoperative scapular neck angle (SNA), prosthesis-scapular neck angle (PSNA), peg glenoid rim distance (PGRD), notching index, and clinical outcomes. There was no significant difference in mean (SD) notching index between group 1, 31.8 (4.4), and group 2, 33.1 (7.3), and there were no significant differences in SNA (102.8° vs 105.4°; P=.3), PSNA (125.8° vs 125.4°; P=.82), PGRD (15.4 vs 16.8 mm; P=.47), or clinical outcomes between the groups. Our results suggest that Grammont-style prostheses have a higher rate of notching regardless of optimal PGRD and variations in PSNA. Perhaps with certain scapular morphology, prosthetic design may be a more significant contributor to notching. PMID:25950544

  19. Robot-Assisted Extended Pelvic Lymph Nodes Dissection for Prostate Cancer: Personal Surgical Technique and Outcomes

    PubMed Central

    Francesco, Porpiglia; Stefano, De Luca; Riccardo, Bertolo; Roberto, Passera; Fabrizio, Mele; Matteo, Manfredi; Daniele, Amparore; Ivano, Morra; Cristian, Fiori

    2015-01-01

    ABSTRACT Objective: Extended pelvic lymph nodes dissection (EPLND) allows the removal of a higher number of lymph nodes than limited PLND. The aims of this study were to describe our robot-assisted EPLND (RAEPLND) technique with related complications, and to report the number of lymph nodes removed and the rate of lymph nodal metastasis. Materials and Methods: 153 patients underwent RAEPLND prior to robot-assisted radical prostatectomy (RARP). Indications were defined according to Briganti nomogram, to predict risk of lymph-nodal metastasis. Lymphatic packages covering the distal tract of the common iliac artery, the medial portion of the external iliac artery, the external iliac vein and the internal iliac vessels, together with the obturator and the presacral lymphatic packages were removed on both sides. Results: Median preoperative PSA was 7.5 ng/mL (IQR 5.5–11.5). Median operative time was 150 min (135–170). Median RAEPLND alone operative time was 38 min (32.75–41.25); for right and left side, 18 (15–29) and 20 min (15.75–30) (p=0.567). Median number of lymph nodes retrieved per patient was 25 (19.25–30); 13 (11–16) and 11 (8–15) for right and left side. In 19 patients (12.41%) metastasis was found at the level of pelvic lymph nodes. Median number of positive lymph nodes was 1 (1–4.6) per patient. Complications occurred in 11 patients (7.3%). Conclusions: the number of lymph nodes removed was comparable to published data about open series, allowing the increase of detection rate of lymph nodal metastasis for minimally invasive approach without compromising complications' rate if performing the procedure following reported technique. PMID:26742982

  20. Laparoscopic surgical technique to facilitate management of high anorectal malformations – report of seven cases

    PubMed Central

    Murawski, Maciej; Łosin, Marcin; Królak, Marek; Czauderna, Piotr

    2011-01-01

    Anorectal malformations (ARMs) occur in approximately 1 per 5000 live births. The most commonly used procedure for repair of high ARMs is posterior sagittal anorectoplasty (PSARP). This operation is performed entirely through a perineal approach. The first report of laparoscopically assisted anorectal pull-through (LAARP) for repair of ARMs was presented by Georgeson in 2000. The aim is presenting early experience with laparoscopically assisted anorectal pull-through technique in boys with high anorectal malformations. In the last 5 years 7 boys (9 months to 2 years old) with high ARMs were operated on using the LAARP technique. Laparoscopically the rectal pouch was exposed down to the urethral fistula, which was clipped and divided. Externally, the centre of the muscle complex was identified using an electrical stimulator. In the first 4 patients after a midline incision of 2 cm at the planned anoplasty site, a tunnel to the pelvis was created bluntly and dilated with Hegar probes under laparoscopic control. In the last 3 boys a minimal PSARP was done creating a channel into the pelvis. The separated rectum was pulled down and sutured to the perineum. Laparoscopic mobilization of the rectal pouch and fistula division was possible in all cases. There were no intraoperative complications except one ureteral injury. Patients were discharged home on post-operative day 5 to 7. The early results prove that LAARP, an alternative option to PSARP for treatment of imperforate anus, offers many advantages, including excellent visualization of the pelvic anatomical structures, accurate placement of the bowel into the muscle complex and a minimally invasive abdominal and perineal incision. It allows for shorter hospital stay and faster recovery. However, to compare the functional results against the standard procedure (PSARP), longer follow-up of all patients is necessary. PMID:23255974

  1. Optimal Use of Wire-Assisted Techniques and Precut Sphincterotomy

    PubMed Central

    Lee, Tae Hoon; Park, Sang-Heum

    2016-01-01

    Various endoscopic techniques have been developed to overcome the difficulties in biliary or pancreatic access during endoscopic retrograde cholangiopancreatography, according to the preference of the endoscopist or the aim of the procedures. In terms of endoscopic methods, guidewire-assisted cannulation is a commonly used and well-known initial cannulation technique, or an alternative in cases of difficult cannulation. In addition, precut sphincterotomy encompasses a range of available rescue techniques, including conventional precut, precut fistulotomy, transpancreatic septotomy, and precut after insertion of pancreatic stent or pancreatic duct guidewire-guided septal precut. We present a literature review of guidewire-assisted cannulation as a primary endoscopic method and the precut technique for the facilitation of selective biliary access. PMID:27642848

  2. Percutaneous endoscopic discectomy: surgical technique and preliminary results compared to microsurgical discectomy.

    PubMed

    Mayer, H M; Brock, M

    1993-02-01

    Percutaneous endoscopic discectomy is a new technique for removing "contained" lumbar disc herniations (those in which the outer border of the anulus fibrosus is intact) and small "noncontained" lumbar disc herniations (those at the level of the disc space and occupying less than one-third of the sagittal diameter of the spinal canal) through a posterolateral approach with the aid of specially developed instruments. The technique combines rigid straight, angled, and flexible forceps with automated high-power suction shaver and cutter systems. Access can thus be gained to the dorsal parts of the intervertebral space where the disc herniation is located. Percutaneous endoscopic discectomy is monitored using an endoscope angled to 70 degrees coupled with a television and video unit and is performed with the patient under local anesthesia and an anesthesiologist available if needed. Its indication is restricted to discogenic root compression with a minor neurological deficit. Two groups of patients with contained or small noncontained disc herniations were treated by either percutaneous endoscopic discectomy (20 cases) or microdiscectomy (20 cases). Both groups were investigated in a prospective randomized study in order to compare the efficacy of the two methods. The disc herniations were located at L2-3 (one patient), L3-4 (two patients), or L4-5 (37 patients). There were no significant differences between the two groups concerning age and sex distribution, preoperative evolution of complaints, prior conservative therapy, patient's occupation, preoperative disability, and clinical symptomatology. Two years after percutaneous endoscopic discectomy, sciatica had disappeared in 80% (16 of 20 patients), low-back pain in 47% (nine of 19 patients), sensory deficits in 92.3% (12 of 13 patients), and motor deficits in the one patient affected. Two years after microdiscectomy, sciatica had disappeared in 65% (13 of 20 patients), low-back pain in 25% (five of 20 patients

  3. Single-Portal Versus Two-Portal Knee Arthroscopy: First Clinical Experience With a New Surgical Technique.

    PubMed

    Cooper, Daniel E

    2016-01-01

    This pilot study compared efficacy, morbidity, and complication rates with a new single-portal arthroscopy technique and traditional 2-portal knee arthroscopy. This prospective study evaluated 156 patients who underwent arthroscopic knee surgery, 106 with 2 portals and a traditional arthroscope and instruments and 50 with a single portal and newly designed arthroscopy instruments. Patients who had reconstructive procedures, microfractures, lateral release procedures, advanced osteoarthritis, and revision surgery were excluded, as were obese patients. The same surgeon performed all procedures, and the patient groups had no significant differences in sex, age, types of pathology, surgical treatment, medications given, or rehabilitation protocol. All patients were examined and completed questionnaires 1 week, 1 month, and 3 months postoperatively. The surgeon was blinded to the data. Follow-up was 100%. The single-portal technique was technically feasible for treatment of knee pathology in 49 of 50 patients. The 2-portal technique provided adequate treatment of knee pathology in all 106 cases. No difference was reported in pain level in the recovery room or on postoperative day 2. However, patients in the single-portal group reported less pain on day 4 (P=.04) and day 7 (P=.004) and were less likely to use oral narcotic analgesics (P=.0001). The single-portal group reported better function in activities of daily living at 1 month and less interference with sports participation at 3 months. Complication rates were no different in the 2 groups. The findings showed that the single-portal technique improved functional recovery at 1 month and 3 months postoperatively and may result in less morbidity in some parameters.

  4. Reconstruction of the mandible and the maxilla: the evolution of surgical technique.

    PubMed

    Genden, Eric M

    2010-01-01

    The upper and lower jaws play an essential role in mastication, articulation, and cosmetic form. The mandible provides support for tongue position and elevation of the larynx during swallowing, while the maxilla provides support for the nasal structures as well as an opposing structure to the mandible during mastication. The evolution of mandibular and maxillary reconstruction dates back to the early 19th century. Before the introduction of free tissue transfer, a variety of local flaps, regional flaps, and prosthetics were introduced, yet each was met with eventual failure. Since the introduction of free tissue transfer, mandibular and maxillary reconstruction has become as much of an art as it has a science. Whether the mandibular or the palatomaxillary defects are a result of trauma, congenital deformity, or tumor extirpation, the resultant effect often disrupts both form and function. With these considerations taken together, jaw reconstruction is a unique undertaking in which the artistic reconstruction of the facial skeleton is met with the science of reestablishing the mechanics of mastication. The site, size, and associated soft-tissue defects represent the 3 most important factors in determining the impact of a given defect on function and aesthetics. There is also an inherent difference between defects that are sustained in a controlled fashion, such as during cancer ablation, and those that result from trauma. The consideration of these complexities in jaw reconstruction is reflected in the wide variety of approaches and techniques that have evolved over the past century. PMID:20231587

  5. Anterograde excision of a sublingual gland: new surgical technique for the treatment of ranulas.

    PubMed

    Liu, Zhigang; Wang, Bin

    2016-02-01

    Wharton's duct is dissected in a retrograde direction from the orifice of the duct to the hilum of the submandibular gland when the gland is being excised conventionally. Here we describe an anterograde technique, in which Wharton's duct is dissected in an anterograde direction from the hilum of the submandibular gland to the orifice of the duct. This prospective clinical study included 50 consecutive patients with ranulas who had anterograde excision of the sublingual gland between May 2012 and January 2015. The intraoral incision was similar to that for conventional excision. Wharton's duct and other important anatomical structures located in the space behind the sublingual gland were all identified at the beginning of the procedure, followed by anterograde dissection of Wharton's duct. After the glandular tissue lateral to the duct had been incised completely, the duct was exposed and the gland cut into two parts. Finally, the two parts were removed, and the ranula ruptured. The patients were followed up from 6 months-2 years. There were no complications. Anterograde excision of the sublingual gland is based on the anatomy, and this reduces the risk of complications after removal of a ranula.

  6. Novel Techniques with the Aid of a Staged CBCT Guided Surgical Protocol

    PubMed Central

    Drew, Howard

    2015-01-01

    The case report will present some novel techniques for using a “staged” protocol utilizing strategic periodontally involved teeth as transitional abutments in combination with CBCT guided implant surgery. Staging the case prevented premature loading of the grafted sites during the healing phase. A CBCT following a tenting screw guided bone regeneration procedure ensured adequate bone to place an implant fixture. Proper assessment of the CBCT allowed the surgeon to do an osteotome internal sinus lift in an optimum location. The depth of the bone needed for the osteotome sinus floor elevation was planned. The staged appliance allowed these sinus-augmented sites to heal for an extended period of time compared to implants, which were uncovered and loaded at an earlier time frame. The staged protocol and CBCT analysis enabled the immediate implants to be placed in proper alignment to the adjacent fixture. After teeth were extracted, the osseointegrated implants were converted to abutments for the transitional appliance. Finally, the staged protocol allowed for soft tissue enhancement in the implant and pontic areas prior to final insertion of the prosthesis. PMID:25632356

  7. Massive cuff tears treated with arthroscopically assisted latissimus dorsi transfer. Surgical technique

    PubMed Central

    De Cupis, Vincenzo; De Cupis, Mauro

    2012-01-01

    Summary Latissimus dorsi transfer is our preferred treatment for active disabled patients with a posterosuperior massive cuff tear. We present an arthroscopically assisted technique which avoids an incision through the deltoid obtaining a better and faster clinical outcome. The patient is placed in lateral decubitus. After the arthroscopic evaluation of the lesion through a posterior and a posterolateral portal, with the limb in traction we perform the preparation of the greater tuberosity of the humerus. We place the arm in abduction and internal rotation and we proceed to the harvest of the latissimus dorsi and the tendon preparation by stitching the two sides using very resistant sutures. After restoring limb traction, under arthroscopic visualization, we pass a curved grasper through the posterolateral portal by going to the armpit in the space between the teres minor and the posterior deltoid. Once the grasper has exited the access at the level of the axilla we fix two drainage transparent tubes, each with a wire inside, and, withdrawing it back, we shuttle the two tubes in the subacromial space. After tensioning the suture wires from the anterior portals these are assembled in a knotless anchor of 5.5 mm that we place in the prepared site on the greater tuberosity of the humerus. A shoulder brace at 15° of abduction and neutral rotation protect the patient for the first month post-surgery but physical therapy can immediately start. PMID:23738290

  8. In vitro characterization of the technique of portal vein embolization by injection of a surgical glue

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Sandulache, Mihai-Cristinel; Lancon, Oceane; El Kadri Benkara, Khadija

    2012-11-01

    Partial embolization of the portal trunk by glue injection is a minimally invasive technique used in the case of malignant liver tumors. It is conducted few weeks prior to partial liver ablation, when the volume of the remnant liver section is too small to allow hepatectomy. The limitation of glue embolotherapy is that its clinical practice is based on empirical knowledge. The present objective is to study glue injection in a confined blood flow and investigate how the injection dynamics is coupled with glue polymerization. We first characterize polymerization under static conditions for various glue concentrations and then consider the influence of injection. An experimental setup reproduces the co-flow of two immiscible fluids. The glue mixture is injected through a capillary tube into a saline solution with the same ionic concentration, pH and viscosity as blood, flowing steadily in a straight cylindrical tube. The injected phase is visualized with a high-speed imaging system and results are compared with those obtained for non-reacting fluids. These experiments have enabled us to characterize the characteristic times of polymerization of the glue mixtures under static and dynamic conditions and understand how they affect the flow topology of the glue once injected. Biomechanics and Bioengineering Laboratory (UMR CNRS 7338).

  9. Surgical stabilization for open tibial fractures in children: External fixation or elastic stable intramedullary nail - which method is optimal?

    PubMed Central

    Ramasubbu, Rohan A; Ramasubbu, Benjamin M

    2016-01-01

    Background: Management of open tibial fractures is well documented in adults, with existing protocols outlining detailed treatment strategies. No clear guidelines exist for children. Surgical stabilization of tibial fractures in the pediatric population requires implants that do not disrupt the open epiphyses (growth plate). Both elastic stable intramedullary nails and external fixation can be used. The objective of this study was to identify the optimal method of surgical stabilization in the treatment of open tibial fractures in children. Materials and Methods: MEDLINE and Embase were searched from their inception to March 2014 using the following advanced search terms (Key words): “open tibia fracture,” “fracture fixation,” “external fixation,” “intramedullary,” and “bone nail.” Only studies in English and pertaining to children with open fractures treated with elastic stable intramedullary nails or external fixation between 1994 and 2014 were included. Twelve clinical studies were critically appraised. Results: Due to a paucity in the literature coupled with a nonsystematic presentation of results, it proved to be very difficult in extracting relevant results from the studies. This was further added by a variation in outcome measures. Consequently, the results we obtained were difficult to draw conclusions from. Conclusion: There is no conclusive evidence or best practice guidelines for their management. Thus, as is highlighted in this study, more research is needed to determine the optimum treatment strategy for this common pediatric injury. The existing literature is of poor quality; consisting mainly of retrospective reviews of patients’ medical records, charts, and radiographs. Carefully designed, high-quality prospective cohort studies utilizing a nationalized multi-hospital approach are needed to improve understanding before protocols and guidelines can be developed and implemented. PMID:27746486

  10. Laparoscopic uterine sling suspension: a new technique of uterine suspension in women desiring surgical management of uterine prolapse with uterine conservation.

    PubMed

    Cutner, A; Kearney, R; Vashisht, A

    2007-09-01

    The surgical management of uterine prolapse in women who wish to retain their uterus remains a challenge. Several techniques have been reported using open abdominal, laparoscopic and vaginal approaches. The laparoscopic approach offers both excellent intraoperative visualisation of supportive and adjacent structures and quick postoperative recovery. Currently, laparoscopic suspension of the uterus to the round ligaments, uterosacral ligaments, suture and synthetic mesh suspension to the sacral promontory have been reported. This report describes a new surgical technique of laparoscopic uterine suspension, which has been performed successfully in eight women. Mersilene tape is used to suspend the uterus to the sacral promontory bilaterally and to recreate new uterosacral ligaments.

  11. The Use of MMF Screws: Surgical Technique, Indications, Contraindications, and Common Problems in Review of the Literature

    PubMed Central

    Cornelius, Carl-Peter; Ehrenfeld, Michael

    2010-01-01

    Mandibulo-maxillary fixation (MMF) screws are inserted into the bony base of both jaws in the process of fracture realignment and immobilisation. The screw heads act as anchor points to fasten wire loops or rubber bands connecting the mandible to the maxilla. Traditional interdental chain-linked wiring or arch bar techniques provide the anchorage by attached cleats, hooks, or eyelets. In comparison to these tooth-borne appliances MMF screws facilitate and shorten the way to achieve intermaxillary fixation considerably. In addition, MMF screws help to reduce the hazards of glove perforation and wire stick injuries. On the downside, MMF screws are attributed with the risk of tooth root damage and a lack of versatility beyond the pure maintenance of occlusion such as stabilizing loose teeth or splinting fragments of the alveolar process. The surgical technique of MMF screws as well as the pros and cons of the clinical application are reviewed. The adequate screw placement to prevent serious tooth root injuries is still an issue to rethink and modify conceptual guidelines. PMID:22110819

  12. Basal Cell Carcinoma of the Outer Nose: Overview on Surgical Techniques and Analysis of 312 Patients

    PubMed Central

    Wollina, Uwe; Bennewitz, Annett; Langner, Dana

    2014-01-01

    Background: Basal cell carcinoma of the nose is common, with a potential of local recurrence and high-risk features. Materials and Methods: We provide a review on anatomy of the nose, tumour surgery and defect closure on the nose. We analysed our own patients with nasal BCC of a 24 months period. Results: We identified 321 patients with nasal BCC. There was a predominance of female patients of 1.2 to 1. The mean age was 74.8 years. Slow Mohs technique was employed for all tumours until 3D tumour-free margins were achieved. That resulted on average in 1.8 ± 0.7 Mohs stages. The most common histologic types were solitary (n = 182), morpheic (79), and micronodular (20), Perineural infiltration was evident in 56 tumours. Primary closure after mobilisation of soft tissue was possible in 105 BCCs. Advancement flaps were used in 91 tumours, rotation flaps in 47, transposition flaps in 34 tumours, and combined procedures in 6 cases. In 36 patients full-thickness skin grafting was performed. In two patients healing by second intention was preferred. Partial flap loss was seen in four patients (1.4%). All of them had significant underlying pathologies. None of the tumours treated showed a relapse during the observation time. However, this is a limitation of the present study since follow-up was on average only 10 months. Conclusions: BCCs of the nose are common. Only 3D-controlled micrographic surgery (Mohs or slow Mohs) guarantee a high rate of complete tumour removal and a very low risk of recurrence. PMID:25538434

  13. Iliac crest allograft glenoid reconstruction for recurrent anterior shoulder instability in athletes: Surgical technique and results

    PubMed Central

    Mascarenhas, Randy; Raleigh, Eden; McRae, Sheila; Leiter, Jeff; Saltzman, Bryan; MacDonald, Peter B.

    2014-01-01

    Performing a labral repair alone in patients with recurrent anterior instability and a large glenoid defect has led to poor outcomes. We present a technique involving the use of the iliac crest allograft inserted into the glenoid defect in athletes with recurrent anterior shoulder instability and large bony defects of the glenoid (>25% of glenoid diameter). All athletes with recurrent anterior shoulder instability and a large glenoid defect that underwent open anterior shoulder stabilization and glenoid reconstruction with the iliac crest allograft were followed over a 4-year period. Preoperatively, a detailed history and physical exam were obtained along with standard radiographs and magnetic resonance imaging of the affected shoulder. All patients also completed the Simple Shoulder Test (SST) and American Shoulder and Elbow Surgeons (ASES) evaluation forms preoperatively. A computed tomography scan was obtained postoperatively to assess osseous union of the graft and the patient again went through a physical exam in addition to completing the SST, ASES, and Western Ontario Shoulder Instability Index (WOSI) forms. 10 patients (9 males, 1 female) were followed for an average of 16 months (4–36 months) and had a mean age of 24.4 years. All patients exhibited a negative apprehension/relocation test and full shoulder strength at final follow-up. Eight of 10 patients had achieved osseous union at 6 months (80.0%). ASES scores improved from 64.3 to 97.8, and SST scores improved from 66.7 to 100. Average postoperative WOSI scores were 93.8%. The use of the iliac crest allograft provides a safe and clinically useful alternative compared to previously described procedures for recurrent shoulder instability in the face of glenoid deficiency. PMID:25538432

  14. Optimization techniques for OpenCL-based linear algebra routines

    NASA Astrophysics Data System (ADS)

    Kozacik, Stephen; Fox, Paul; Humphrey, John; Kuller, Aryeh; Kelmelis, Eric; Prather, Dennis W.

    2014-06-01

    The OpenCL standard for general-purpose parallel programming allows a developer to target highly parallel computations towards graphics processing units (GPUs), CPUs, co-processing devices, and field programmable gate arrays (FPGAs). The computationally intense domains of linear algebra and image processing have shown significant speedups when implemented in the OpenCL environment. A major benefit of OpenCL is that a routine written for one device can be run across many different devices and architectures; however, a kernel optimized for one device may not exhibit high performance when executed on a different device. For this reason kernels must typically be hand-optimized for every target device family. Due to the large number of parameters that can affect performance, hand tuning for every possible device is impractical and often produces suboptimal results. For this work, we focused on optimizing the general matrix multiplication routine. General matrix multiplication is used as a building block for many linear algebra routines and often comprises a large portion of the run-time. Prior work has shown this routine to be a good candidate for high-performance implementation in OpenCL. We selected several candidate algorithms from the literature that are suitable for parameterization. We then developed parameterized kernels implementing these algorithms using only portable OpenCL features. Our implementation queries device information supplied by the OpenCL runtime and utilizes this as well as user input to generate a search space that satisfies device and algorithmic constraints. Preliminary results from our work confirm that optimizations are not portable from one device to the next, and show the benefits of automatic tuning. Using a standard set of tuning parameters seen in the literature for the NVIDIA Fermi architecture achieves a performance of 1.6 TFLOPS on an AMD 7970 device, while automatically tuning achieves a peak of 2.7 TFLOPS

  15. Optimal feedback control infinite dimensional parabolic evolution systems: Approximation techniques

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Wang, C.

    1989-01-01

    A general approximation framework is discussed for computation of optimal feedback controls in linear quadratic regular problems for nonautonomous parabolic distributed parameter systems. This is done in the context of a theoretical framework using general evolution systems in infinite dimensional Hilbert spaces. Conditions are discussed for preservation under approximation of stabilizability and detectability hypotheses on the infinite dimensional system. The special case of periodic systems is also treated.

  16. Asynchronous global optimization techniques for medium and large inversion problems

    SciTech Connect

    Pereyra, V.; Koshy, M.; Meza, J.C.

    1995-04-01

    We discuss global optimization procedures adequate for seismic inversion problems. We explain how to save function evaluations (which may involve large scale ray tracing or other expensive operations) by creating a data base of information on what parts of parameter space have already been inspected. It is also shown how a correct parallel implementation using PVM speeds up the process almost linearly with respect to the number of processors, provided that the function evaluations are expensive enough to offset the communication overhead.

  17. An Optimal Cell Detection Technique for Automated Patch Clamping

    NASA Technical Reports Server (NTRS)

    McDowell, Mark; Gray, Elizabeth

    2004-01-01

    While there are several hardware techniques for the automated patch clamping of cells that describe the equipment apparatus used for patch clamping, very few explain the science behind the actual technique of locating the ideal cell for a patch clamping procedure. We present a machine vision approach to patch clamping cell selection by developing an intelligent algorithm technique that gives the user the ability to determine the good cell to patch clamp in an image within one second. This technique will aid the user in determining the best candidates for patch clamping and will ultimately save time, increase efficiency and reduce cost. The ultimate goal is to combine intelligent processing with instrumentation and controls in order to produce a complete turnkey automated patch clamping system capable of accurately and reliably patch clamping cells with a minimum amount of human intervention. We present a unique technique that identifies good patch clamping cell candidates based on feature metrics of a cell's (x, y) position, major axis length, minor axis length, area, elongation, roundness, smoothness, angle of orientation, thinness and whether or not the cell is only particularly in the field of view. A patent is pending for this research.

  18. Prospective Study of the Surgical Techniques Used in Primary Rhinoplasty on the Caucasian Nose and Comparison of the Preoperative and Postoperative Anthropometric Nose Measurements

    PubMed Central

    Berger, Cezar Augusto Sarraf; Freitas, Renato da Silva; Malafaia, Osvaldo; Pinto, José Simão de Paula; Macedo Filho, Evaldo Dacheux; Mocellin, Marcos; Fagundes, Marina Serrato Coelho

    2014-01-01

    Introduction The knowledge and study of surgical techniques and anthropometric measurements of the nose make possible a qualitative and quantitative analysis of surgical results. Objective Study the main technique used in rhinoplasty on Caucasian noses and compare preoperative and postoperative anthropometric measurements of the nose. Methods A prospective study with 170 patients was performed at a private hospital. Data were collected using the Electronic System Integrated of Protocols software (Sistema Integrado de Protocolos Eletrônicos, SINPE©). The surgical techniques used in the nasal dorsum and tip were evaluated. Preoperative and 12-month follow-up photos as well as the measurements compared with the ideal aesthetic standard of a Caucasian nose were analyzed objectively. Student t test and standard deviation test were applied. Results There was a predominance of endonasal access (94.4%). The most common dorsum technique was hump removal (33.33%), and the predominance of sutures (24.76%) was observed on the nasal tip, with the lateral intercrural the most frequent (32.39%). Comparison between preoperative and postoperative photos found statistically significant alterations on the anthropometric measurements of the noses. Conclusion The main surgical techniques on Caucasian noses were evaluated, and a great variety was found. The evaluation of anthropometric measurements of the nose proved the efficiency of the performed procedures. PMID:25992149

  19. Insight into current surgical techniques and practice patterns associated with robotic-assisted radical prostatectomy: a national survey of urologists within the USA.

    PubMed

    Dyche, Damon J; Coffey, Mary; Sarle, Richard; Kernen, Kenneth; Seifman, Brian; Relle, James; Hollander, Jay; Hafron, Jason

    2010-08-01

    Robotic-assisted radical prostatectomy (RARP) has been rapidly adopted throughout the USA. The purpose of this study is to describe the prevailing RARP operative techniques and perceptions within the USA. An anonymous web-based survey was sent electronically to a list of 920 robotic urological surgeons. The survey assessed surgeon demographics, surgical technique, and postoperative care related to RARP. The study was comprised of urologists from community hospitals (76%) and university hospitals/specialty centers (24%). All geographic sections of the American Urological Association were represented. The most common neurovascular preservation techniques were ante/retrograde approach (48%), athermal (22%), and preservation of lateral pelvic fascia (17%). Surgeon choice of neurovascular preservation technique varied with the average number of procedures performed per year (P = 0.0065). High-volume surgeons tended to require a higher number of robotic cases in order to go through the learning curve of the "comfortable" (P = 0.001) and "expert" levels (P < 0.0001). The majority of surgeons reported that RARP (as compared with open surgery) improved urinary continence (77.2%), sexual function (65.6%), and surgical margin rates (53.8%). RARP is an evolving surgical procedure with significant variability in practice patterns among US surgeons. Further studies are necessary to compare the various techniques in order to improve surgical outcomes. PMID:27628775

  20. Coordination and Control of Multiple Spacecraft using Convex Optimization Techniques

    NASA Astrophysics Data System (ADS)

    How, Jonathan P.

    2002-06-01

    Formation flying of multiple spacecraft is an enabling technology for many future space science missions. These future missions will, for example, use the highly coordinated, distributed array of vehicles for earth mapping interferometers and synthetic aperture radar. This thesis presents coordination and control algorithms designed for a fleet of spacecraft. These algorithms are embedded in a hierarchical fleet archi- tecture that includes a high-level coordinator for the fleet maneuvers used to form, re-size, or re-target the formation configuration and low-level controllers to generate and implement the individual control inputs for each vehicle. The trajectory and control problems are posed as linear programming (LP) optimizations to solve for the minimum fuel maneuvers. The combined result of the high-level coordination and low-level controllers is a very flexible optimization framework that can be used off-line to analyze aspects of a mission design and in real-time as part of an on-board autonomous formation flying control system. This thesis also investigates several crit- ical issues associated with the implementation of this formation flying approach. In particular, modifications to the LP algorithms are presented to: include robustness to sensor noise, include actuator constraints, ensure that the optimization solutions are always feasible, and reduce the LP solution times. Furthermore, the dynamics for the control problem are analyzed in terms of two key issues: 1) what dynamics model should be used to specify the desired state to maintain a passive aperture; and 2) what dynamics model should be used in the LP to represent the motion about this state. Several linearized models of the relative dynamics are considered in this analysis, including Hill's equations for circular orbits, modified linear dynamics that partially account for the J2 effects, and Lawden's equations for eccentric orbits.

  1. Basic Surgical Techniques in the Göttingen Minipig: Intubation, Bladder Catheterization, Femoral Vessel Catheterization, and Transcardial Perfusion

    PubMed Central

    Ettrup, Kaare S.; Glud, Andreas N.; Orlowski, Dariusz; Fitting, Lise M.; Meier, Kaare; Soerensen, Jens Christian; Bjarkam, Carsten R.; Alstrup, Aage K. Olsen

    2011-01-01

    The emergence of the Göttingen minipig in research of topics such as neuroscience, toxicology, diabetes, obesity, and experimental surgery reflects the close resemblance of these animals to human anatomy and physiology 1-6.The size of the Göttingen minipig permits the use of surgical equipment and advanced imaging modalities similar to those used in humans 6-8. The aim of this instructional video is to increase the awareness on the value of minipigs in biomedical research, by demonstrating how to perform tracheal intubation, transurethral bladder catheterization, femoral artery and vein catheterization, as well as transcardial perfusion. Endotracheal Intubation should be performed whenever a minipig undergoes general anesthesia, because it maintains a patent airway, permits assisted ventilation and protects the airways from aspirates. Transurethral bladder catheterization can provide useful information about about hydration state as well as renal and cardiovascular function during long surgical procedures. Furthermore, urinary catheterization can prevent contamination of delicate medico-technical equipment and painful bladder extension which may harm the animal and unnecessarily influence the experiment due to increased vagal tone and altered physiological parameters. Arterial and venous catheterization is useful for obtaining repeated blood samples and monitoring various physiological parameters. Catheterization of femoral vessels is preferable to catheterization of the neck vessels for ease of access, when performing experiments involving frame-based stereotaxic neurosurgery and brain imaging. When performing vessel catheterization in survival studies, strict aseptic technique must be employed to avoid infections6. Transcardial perfusion is the most effective fixation method, and yields preeminent results when preparing minipig organs for histology and histochemistry2,9. For more information about anesthesia, surgery and experimental techniques in swine in

  2. Surgical Techniques to Increase the Apicocoronal Dimension of the Attached Gingiva: A 1-Year Comparison Between the Free Gingival Graft and the Modified Apically Repositioned Flap.

    PubMed

    Carnio, João; Camargo, Paulo M; Pirih, Paulo Q

    2015-01-01

    The attached gingiva is a desirable anatomical element for the maintenance of gingival health. The free gingival graft (FGG) and the modified apically repositioned flap (MARF) are predictable surgical techniques often employed to increase the zone of attached gingiva. This randomized study compared the FGG and the MARF in increasing the zone of attached gingiva in contralateral sides of 15 patients 1 year posttreatment. There was an increase in keratinized tissue and attached gingiva in both groups. Gingival recession did not significantly change between pre- and posttreatment levels in either group. The MARF surgical time was approximately half as long as that of the FGG. The authors conclude that both techniques are viable; however, the main advantages of the MARF were decreased surgical time and less postoperative discomfort.

  3. Benign tumours affecting the deep lobe of the parotid gland: how to select the optimal surgical approach.

    PubMed

    Casani, A P; Cerchiai, N; Dallan, I; Seccia, V; Sellari Franceschini, S

    2015-04-01

    Many types of approaches allow extra-capsular dissection in the deep parotid parenchyma in the treatment of benign tumours. A transcervical approach (TCA), transparotid approach (TPA) and a combined transcervical-transparotid approach (TPTCA) are the three main procedures performed to expose the deep parenchyma. We conducted a retrospective chart review enrolling 24 consecutive patients treated for benign tumours affecting the deep lobe of the parotid. Review of the surgical data was accompanied by careful follow-up to establish surgical morbidity, functional (Frey's Syndrome and first-bite syndrome) and aesthetical outcomes. A TPA was performed in the majority of cases; in 26% superficial parotidectomy was not required (selective deep parotidectomy). Minor's test showed a low rate of Frey's syndrome (3 cases of 23, 13%). No long-lasting first-bite syndrome was reported. Some additional procedures were easily performed in order to improve aesthetical results (rotational flap of sternocleidomastoid muscle, free abdominal fat transfer); these had the same results as selective deep parotidectomy. TCA (or TPTCA) ensures the best control of the facial nerve, providing good exposure and good functional and aesthetical results (without sparing the superficial parenchyma if additional techniques are performed with the aim of reducing skin depression in the treated area). The choice of the approach should have only the aim of safe resection and should not be influenced by aesthetical outcome; the craniocaudal level of the tumour seems to be the best indicator of the feasibility of the procedure also considering the branches of the facial nerve. In our experience, mandibulotomy can always be avoided.

  4. Decomposition technique and optimal trajectories for the aeroassisted flight experiment

    NASA Technical Reports Server (NTRS)

    Miele, A.; Wang, T.; Deaton, A. W.

    1990-01-01

    An actual geosynchronous Earth orbit-to-low Earth orbit (GEO-to-LEO) transfer is considered with reference to the aeroassisted flight experiment (AFE) spacecraft, and optimal trajectories are determined by minimizing the total characteristic velocity. The optimization is performed with respect to the time history of the controls (angle of attack and angle of bank), the entry path inclination and the flight time being free. Two transfer maneuvers are considered: direct ascent (DA) to LEO and indirect ascent (IA) to LEO via parking Earth orbit (PEO). By taking into account certain assumptions, the complete system can be decoupled into two subsystems: one describing the longitudinal motion and one describing the lateral motion. The angle of attack history, the entry path inclination, and the flight time are determined via the longitudinal motion subsystem. In this subsystem, the difference between the instantaneous bank angle and a constant bank angle is minimized in the least square sense subject to the specified orbital inclination requirement. Both the angles of attack and the angle of bank are shown to be constant. This result has considerable importance in the design of nominal trajectories to be used in the guidance of AFE and aeroassisted orbital transfer (AOT) vehicles.

  5. Decomposition technique and optimal trajectories for the aeroassisted flight experiment

    NASA Technical Reports Server (NTRS)

    Miele, A.; Wang, T.; Deaton, A. W.

    1991-01-01

    An actual geosynchronous earth orbit-to-low earth orbit (GEO-to-LEO) transfer is considered with reference to the aeroassisted flight experiment (AFE) spacecraft, and optimal trajectories are determined by minimizing the total characteristic velocity. The optimization is performed with respect to the time history of the controls (angle of attack and angle of bank), the entry path inclination and the flight time being free. Two transfer maneuvers are considered: direct ascent (DA) to LEO and indirect ascent (IA) to LEO via parking earth orbit (PEO). By taking into account certain assumptions, the complete system can be decoupled into two subsystems: one describing the longitudinal motion and one describing the lateral motion. The angle of attack history, the entry path inclination, and the flight time are determined via the longitudinal motion subsystem. In this subsystem, the difference between the instantaneous bank angle and a constant bank angle is minimized in the least square sense subject to the specified orbital inclination requirement. Both the angles of attack and the angle of bank are shown to be constant. This result has considerable importance in the design of nominal trajectories to be used in the guidance of AFE and aeroassisted orbital transfer (AOT) vehicles.

  6. Nonparametric probability density estimation by optimization theoretic techniques

    NASA Technical Reports Server (NTRS)

    Scott, D. W.

    1976-01-01

    Two nonparametric probability density estimators are considered. The first is the kernel estimator. The problem of choosing the kernel scaling factor based solely on a random sample is addressed. An interactive mode is discussed and an algorithm proposed to choose the scaling factor automatically. The second nonparametric probability estimate uses penalty function techniques with the maximum likelihood criterion. A discrete maximum penalized likelihood estimator is proposed and is shown to be consistent in the mean square error. A numerical implementation technique for the discrete solution is discussed and examples displayed. An extensive simulation study compares the integrated mean square error of the discrete and kernel estimators. The robustness of the discrete estimator is demonstrated graphically.

  7. A technique for optimizing the design of power semiconductor devices

    NASA Technical Reports Server (NTRS)

    Schlegel, E. S.

    1976-01-01

    A technique is described that provides a basis for predicting whether any device design change will improve or degrade the unavoidable trade-off that must be made between the conduction loss and the turn-off speed of fast-switching high-power thyristors. The technique makes use of a previously reported method by which, for a given design, this trade-off was determined for a wide range of carrier lifetimes. It is shown that by extending this technique, one can predict how other design variables affect this trade-off. The results show that for relatively slow devices the design can be changed to decrease the current gains to improve the turn-off time without significantly degrading the losses. On the other hand, for devices having fast turn-off times design changes can be made to increase the current gain to decrease the losses without a proportionate increase in the turn-off time. Physical explanations for these results are proposed.

  8. Finger joint force minimization in pianists using optimization techniques.

    PubMed

    Harding, D C; Brandt, K D; Hillberry, B M

    1993-12-01

    A numerical optimization procedure was used to determine finger positions that minimize and maximize finger tendon and joint force objective functions during piano play. A biomechanical finger model for sagittal plane motion, based on finger anatomy, was used to investigate finger tendon tensions and joint reaction forces for finger positions used in playing the piano. For commonly used piano key strike positions, flexor and intrinsic muscle tendon tensions ranged from 0.7 to 3.2 times the fingertip key strike force, while resultant inter-joint compressive forces ranged from 2 to 7 times the magnitude of the fingertip force. In general, use of a curved finger position, with a large metacarpophalangeal joint flexion angle and a small proximal interphalangeal joint flexion angle, reduces flexor tendon tension and resultant finger joint force.

  9. PRE-OPERATIVE PLANNING AND SURGICAL TECHNIQUE OF THE OPEN WEDGE SUPRACONDYLAR OSTEOTOMY FOR CORRECTION OF VALGUS KNEE AND FIXATION WITH A FIXED-ANGLE IMPLANT

    PubMed Central

    Paccola, Cleber Antonio Jansen

    2015-01-01

    The step-by-step preoperative planning for supracondylar opening wedge osteotomy of the femur for precise correction of the load axis of the lower limb using a fixed-angle implant (95° AO blade plate) is presented. The surgical technique and the use of a bone graft from the same site for filling in the defect are also presented. PMID:27026976

  10. Intermediate-Term Outcomes of Dual Adult versus Single-Kidney Transplantation: Evolution of a Surgical Technique.

    PubMed

    Islam, Ana K; Knight, Richard J; Mayer, Wesley A; Hollander, Adam B; Patel, Samir; Teeter, Larry D; Graviss, Edward A; Saharia, Ashish; Podder, Hemangshu; Asham, Emad H; Gaber, A Osama

    2016-01-01

    Background. Acceptance of dual kidney transplantation (DKT) has proven difficult, due to surgical complexity and concerns regarding long-term outcomes. We herein present a standard technique for ipsilateral DKT and compare outcomes to single-kidney transplant (SKT) recipients. Methods. A retrospective single-center comparison of DKT and SKT performed between February 2007 and July 2013. Results. Of 516 deceased donor kidney transplants, 29 were DKT and 487 were SKT. Mean follow-up was 43 ± 67 months. DKT recipients were older and more likely than SKT recipients to receive an extended criteria graft (p < 0.001). For DKT versus SKT, the rates of delayed graft function (10.3 versus 9.2%) and acute rejection (20.7 versus 22.4%) were equivalent (p = ns). A higher than expected urologic complication rate in the DKT cohort (14 versus 2%, p < 0.01) was reduced through modification of the ureteral anastomosis. Graft survival was equivalent between DKT and SKT groups (p = ns) with actuarial 3-year DKT patient and graft survivals of 100% and 93%. At 3 years, the groups had similar renal function (p = ns). Conclusions. By utilizing extended criteria donor organs as DKT, the donor pool was enlarged while providing excellent patient and graft survival. The DKT urologic complication rate was reduced by modification of the ureteral anastomosis.

  11. Intermediate-Term Outcomes of Dual Adult versus Single-Kidney Transplantation: Evolution of a Surgical Technique

    PubMed Central

    Islam, Ana K.; Mayer, Wesley A.; Hollander, Adam B.; Patel, Samir; Teeter, Larry D.; Graviss, Edward A.; Saharia, Ashish; Podder, Hemangshu; Asham, Emad H.; Gaber, A. Osama

    2016-01-01

    Background. Acceptance of dual kidney transplantation (DKT) has proven difficult, due to surgical complexity and concerns regarding long-term outcomes. We herein present a standard technique for ipsilateral DKT and compare outcomes to single-kidney transplant (SKT) recipients. Methods. A retrospective single-center comparison of DKT and SKT performed between February 2007 and July 2013. Results. Of 516 deceased donor kidney transplants, 29 were DKT and 487 were SKT. Mean follow-up was 43 ± 67 months. DKT recipients were older and more likely than SKT recipients to receive an extended criteria graft (p < 0.001). For DKT versus SKT, the rates of delayed graft function (10.3 versus 9.2%) and acute rejection (20.7 versus 22.4%) were equivalent (p = ns). A higher than expected urologic complication rate in the DKT cohort (14 versus 2%, p < 0.01) was reduced through modification of the ureteral anastomosis. Graft survival was equivalent between DKT and SKT groups (p = ns) with actuarial 3-year DKT patient and graft survivals of 100% and 93%. At 3 years, the groups had similar renal function (p = ns). Conclusions. By utilizing extended criteria donor organs as DKT, the donor pool was enlarged while providing excellent patient and graft survival. The DKT urologic complication rate was reduced by modification of the ureteral anastomosis. PMID:27478630

  12. Tumour recurrence after surgical removal of parotid pleomorphic salivary adenoma using a retrograde facial nerve dissection technique.

    PubMed

    O'Regan, Barry; Bharadwaj, Girish

    2012-07-01

    Recurrence after surgical removal of parotid pleomorphic salivary adenoma using retrograde facial nerve dissection is not well researched. We adopted retrograde nerve dissection for parotid surgery for benign disease as a standard procedure in 1995. The objective of this study was to establish the rate of recurrence of primary tumours associated with the technique after removal of parotid pleomorphic salivary adenoma. We recruited 59 patients over a 16-year (1995-2011) period and collected the data prospectively. Eight patients were excluded as they had died or had been lost to follow up. Male:female ratio was 16:35 and age range was 15-69 years. The mean tumour size as measured on magnetic resonance imaging (MRI) was 27.4mm. Thirty-eight patients had superficial parotidectomy, 8 had total parotidectomy, and 5 had partial superficial parotidectomy. Mean follow up from the date of operation was 104 months (median 98, range 17-171). All patients were reviewed and examined in 2011 to establish whether the tumour had recurred. One patient had developed a solitary nodular recurrence 8 years after the initial procedure. Recurrence was 2%. The rate of clinically apparent recurrence after parotidectomy for pleomorphic salivary adenoma in this study is low and is comparable with others reported.

  13. Investigation on the use of optimization techniques for helicopter airframe vibrations design studies

    NASA Technical Reports Server (NTRS)

    Sreekanta Murthy, T.

    1992-01-01

    Results of the investigation of formal nonlinear programming-based numerical optimization techniques of helicopter airframe vibration reduction are summarized. The objective and constraint function and the sensitivity expressions used in the formulation of airframe vibration optimization problems are presented and discussed. Implementation of a new computational procedure based on MSC/NASTRAN and CONMIN in a computer program system called DYNOPT for optimizing airframes subject to strength, frequency, dynamic response, and dynamic stress constraints is described. An optimization methodology is proposed which is thought to provide a new way of applying formal optimization techniques during the various phases of the airframe design process. Numerical results obtained from the application of the DYNOPT optimization code to a helicopter airframe are discussed.

  14. Epitympanoplasty with cartilage obliteration in the preservation of posterior canal wall: a technique for surgical treatment of attic cholesteatoma.

    PubMed

    Liu, Yang; Sun, Jianjun; Zhao, Danheng; Lin, Yongsheng

    2014-05-01

    To report and evaluate the surgical outcomes of the treatment of attic cholesteatoma using epitympanoplasty with cartilage obliteration in the preservation of the posterior canal wall. Our study group consists of 138 subjects with attic cholesteatoma who underwent surgery of the mastoidectomy of the intact posterior canal wall and epitympanoplasty with cartilage obliteration, from November 2008 to November 2010. The major techniques employed included the following: (1) mastoidectomy with the preservation of the posterior canal; (2) removal of the scutum; (3) epitympanum obliteration with cartilage, and (4) mastoid obliteration with bone dust. The post-operative observation period was between 2 and 4 years. All patients were examined via microscopy and oto-endoscopy. Of these 138 subjects, 91 subjects have a follow up period of more than 3 years. There was no retraction pocket formation in the epitympanum in all cases. However, in two subjects, there was a recurrence of cholesteatoma within the mesotympanum. Other observable post-surgery complications were also recorded. For hearing results, 64 of the 138 subjects underwent post-operative audiometric testing for 2 to 3 years and 3 to 4 years consecutively. The average pre- and post-operative air-bone gap closure was found to be 11.97 ± 11.02 dB for the 2 to 3 year period, and 10.08 ± 10.34 dB for the 3 to 4 year period. Based on the results of our study group, epitympanoplasty with cartilage obliteration in the preservation of the posterior canal wall is a better alternative treatment technique for attic cholesteatoma. PMID:23589157

  15. First Robotic-Assisted Dual Kidney Transplant: Surgical Technique and Report of a Case With 24-month Follow-up

    PubMed Central

    Frongia, Mauro; Cadoni, Rossano; Solinas, Andrea

    2015-01-01

    Background Open surgery is the gold standard procedure for kidney transplantation. There is a strong rationale for using minimally invasive surgery in patients with end-stage renal disease. A robotic-assisted dual kidney transplant was performed for the first time at our institution. Methods In August 2013, a 63-year-old man with end-stage renal disease and diabetes mellitus under pharmacological control received both kidneys from a 70-year-old marginal donor. Pretransplant donor biopsy demonstrated a bilateral Karpinski score greater than 5. The organs did not exhibit malformations and each had an artery and a vein. The procedure was carried out by a 7-port intraperitoneal approach using the da Vinci surgical system. The procedure was identical for the 2 kidneys except that mobilization of the sigmoid colon was required to introduce the left graft. The renal vessels were anastomosed to the left external iliac vessels. The novel aspect of the technique was the introduction of both grafts through a single, 7-cm upper midline incision. Results Total operative time was 400 minutes and blood loss was 120 mL. Both grafts immediately began functioning. There were no intraoperative or postoperative complications. The patient was discharged on the seventh postoperative day with normal renal function. At 24 months, he is well and does not require hemodialysis. Conclusions Minimally invasive robotic-assisted technology is a promising technique that provides exceptional patient outcomes by reducing operative morbidity, immobilization, and time to recovery, while affording better esthetic results. Selected patients with multiple comorbidities benefit most. Grafts from marginal donors are an extremely valuable resource. PMID:27500234

  16. Surgical approaches for the management of idiopathic thoracic scoliosis and the indications for combined anterior-posterior technique.

    PubMed

    Rauzzino, M J; Shaffrey, C I; Wagner, J; Nockels, R; Abel, M

    1999-05-15

    The indications for surgical intervention in patients with idiopathic scoliosis have been well defined. The goals of surgery are to achieve fusion and arrest progressive curvature while restoring normal coronal and sagittal balance. As first introduced by Harrington, posterior fusion, the gold standard of treatment, has a proven record of success. More recently, anterior techniques for performing fusion procedures via either a thoracotomy or a retroperitoneal approach have been popularized in attempts to achieve better correction of curvature, preserve motion segments, and avoid some of the complications of posterior fusion such as the development of the flat-back syndrome. Anterior instrumentation alone, although effective, can be kyphogenic and has been shown to be associated with complications such as pseudarthrosis and instrumentation failure. Performing a combined approach in patients with scoliosis and other deformities has become an increasingly popular procedure to achieve superior correction of deformity and to minimize later complications. Indications for a combined approach (usually consisting of anterior release, arthrodesis with or without use of instrumentation, and posterior segmental fusion) include: prevention of crankshaft phenomenon in juvenile or skeletally immature adolescents; correction of large curves (75 degrees ) or excessively rigid curves in skeletally mature or immature patients; correction of curves with large sagittal-plane deformities such as thoracic kyphosis (> 90 degrees ) or thoracic lordosis (> 20 degrees ); and correction of thoracolumbar curves that need to be fused to the sacrum. Surgery may be performed either in a staged proceedure or, more commonly, in a single sitting. The authors discuss techniques for combined surgery and complication avoidance. PMID:17031912

  17. Optimized digital filtering techniques for radiation detection with HPGe detectors

    NASA Astrophysics Data System (ADS)

    Salathe, Marco; Kihm, Thomas

    2016-02-01

    This paper describes state-of-the-art digital filtering techniques that are part of GEANA, an automatic data analysis software used for the GERDA experiment. The discussed filters include a novel, nonlinear correction method for ballistic deficits, which is combined with one of three shaping filters: a pseudo-Gaussian, a modified trapezoidal, or a modified cusp filter. The performance of the filters is demonstrated with a 762 g Broad Energy Germanium (BEGe) detector, produced by Canberra, that measures γ-ray lines from radioactive sources in an energy range between 59.5 and 2614.5 keV. At 1332.5 keV, together with the ballistic deficit correction method, all filters produce a comparable energy resolution of ~1.61 keV FWHM. This value is superior to those measured by the manufacturer and those found in publications with detectors of a similar design and mass. At 59.5 keV, the modified cusp filter without a ballistic deficit correction produced the best result, with an energy resolution of 0.46 keV. It is observed that the loss in resolution by using a constant shaping time over the entire energy range is small when using the ballistic deficit correction method.

  18. Calculation of free fall trajectories based on numerical optimization techniques

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The development of a means of computing free-fall (nonthrusting) trajectories from one specified point in the solar system to another specified point in the solar system in a given amount of time was studied. The problem is that of solving a two-point boundary value problem for which the initial slope is unknown. Two standard methods of attack exist for solving two-point boundary value problems. The first method is known as the initial value or shooting method. The second method of attack for two-point boundary value problems is to approximate the nonlinear differential equations by an appropriate linearized set. Parts of both boundary value problem solution techniques described above are used. A complete velocity history is guessed such that the corresponding position history satisfies the given boundary conditions at the appropriate times. An iterative procedure is then followed until the last guessed velocity history and the velocity history obtained from integrating the acceleration history agree to some specified tolerance everywhere along the trajectory.

  19. Use of an infrared temperature monitoring system to determine optimal temperature for arterial repair using light-activated surgical adhesive

    NASA Astrophysics Data System (ADS)

    Soller, Eric C.; Hoffman, Grant T.; McNally-Heintzelman, Karen M.

    2003-06-01

    The ability to reproduce strong repairs is essential to establishing the reliability of laser-tissue soldering techniques and advancing their use to the clinical setting. While some thermal damage is necessary to achieve a viable solder-tissue bond, excessive thermal damage leads to decreased flexibility and strength of the repair. In addition, if the temperature at the solder/tissue interface is too low, inadequate solder-tissue bonding will occur to provide a strong repair. This suggests the presence of an optimal temperature for laser-tissue repair. The choice of solder material presents another challenge to the reproducibility of strong repairs. The emerging use of chromophore-enhanced solder-doped polymer scaffolds offers numerous advantages over more traditional liquid and solid solders composed of serum albumin and an absorbing chromophore mixed in deionized water. Polymer scaffolds, fabricated from poly(L-lactic-co-glycolic acid) using a solvent casting and particulate leaching technique, are porous enough to absorb serum albumin and can also be doped with various hemostatic and thrombogenic agents to aid in tissue healing. Use of the polymer scaffolds allows one to combine the strength of solid solders and the flexibility of liquid solders without the common "runaway" problems. An in vitro study was performed to correlate tissue temperature with the tensile strength of arterial repairs formed using the chromophore-enhanced solder-doped polymer scaffolds. Laser irradiance was varied and the solder surface and solder/tissue interface temperatures were monitored by an IR temperature monitoring system and a type-K thermocouple, respectively. The solder/tissue interface temperature required for optimized tensile strength was determined to be 67 +/- 5°C. This value was in agreement with previous studies using serum albumin solders alone, where the optimal solder/tissue interface temperature was found to be 65°C.

  20. A technique for locating function roots and for satisfying equality constraints in optimization

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, Jaroslaw

    1991-01-01

    A new technique for locating simultaneous roots of a set of functions is described. The technique is based on the property of the Kreisselmeier-Steinhauser function which descends to a minimum at each root location. It is shown that the ensuing algorithm may be merged into any nonlinear programming method for solving optimization problems with equality constraints.

  1. A new model of abdominal aortic aneurysm with gastric serosa patch: surgical technique and short-term evaluation.

    PubMed

    Usón-Gargallo, Jesús; Crisóstomo, Verónica; Loscertales, Beatriz; Sun, Fei; Sánchez-Margallo, Francisco M; Martín-Cancho, Maria F; Maynar, Manuel

    2006-01-01

    The purpose of this work was to develop an abdominal aortic aneurysm (AAA) model that resembles human aneurysms with potential for further growth, patent collateral vessels, and a predictable tendency to rupture, and that can be used in the development of new endoprostheses and implant training. An infrarenal AAA model was created in five domestic swine using an autologous gastric serosal patch. Pre- and postsurgical digital subtraction aortograms (DSA) were obtained to document the appearance and dimensions of the aneurysm. Animals were followed up with DSA and ultrasonography on days 7, 14, 30, 45, 60, and 90 after model creation. Aneurysmal diameters were measured with both techniques in all examinations. On day 90, animals were euthanized, target arteries were harvested, and pathological evaluation was performed. The nonparametric Wilcoxon test was used to assess any differences in measured diameters. All the animals survived the surgical procedure. The aneurysmal diameters increased from 8.14+/- 2.15 to 13.28+/- 1.18 mm immediately after surgery (p < .05), but no subsequent significant growth of the aneurysmal sac was seen during follow-up. In this experimental setting, measurements obtained with DSA were slightly larger than those obtained with ultrasound. Two animals died of AAA rupture on days 6 and 10 (40% rupture rate). Pathological examination showed lack of elastic laminae and increased collagen content in the aortic patch. Thus, model showed a tendency to rupture, but no significant potential for further aneurysmal growth. It might be useful for training in endovascular therapies, but its usefulness for preclinical endovascular device testing is limited by its lack of growth potential. PMID:16531367

  2. Practical Framework for an Electron Beam Induced Current Technique Based on a Numerical Optimization Approach

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hideshi; Soeda, Takeshi

    2015-03-01

    A practical framework for an electron beam induced current (EBIC) technique has been established for conductive materials based on a numerical optimization approach. Although the conventional EBIC technique is useful for evaluating the distributions of dopants or crystal defects in semiconductor transistors, issues related to the reproducibility and quantitative capability of measurements using this technique persist. For instance, it is difficult to acquire high-quality EBIC images throughout continuous tests due to variation in operator skill or test environment. Recently, due to the evaluation of EBIC equipment performance and the numerical optimization of equipment items, the constant acquisition of high contrast images has become possible, improving the reproducibility as well as yield regardless of operator skill or test environment. The technique proposed herein is even more sensitive and quantitative than scanning probe microscopy, an imaging technique that can possibly damage the sample. The new technique is expected to benefit the electrical evaluation of fragile or soft materials along with LSI materials.

  3. Surgical innovation as sui generis surgical research.

    PubMed

    Lotz, Mianna

    2013-12-01

    Successful innovative 'leaps' in surgical technique have the potential to contribute exponentially to surgical advancement, and thereby to improved health outcomes for patients. Such innovative leaps often occur relatively spontaneously, without substantial forethought, planning, or preparation. This feature of surgical innovation raises special challenges for ensuring sufficient evaluation and regulatory oversight of new interventions that have not been the subject of controlled investigatory exploration and review. It is this feature in particular that makes early-stage surgical innovation especially resistant to classification as 'research', with all of the attendant methodological and ethical obligations--of planning, regulation, monitoring, reporting, and publication--associated with such a classification. This paper proposes conceptual and ethical grounds for a restricted definition according to which innovation in surgical technique is classified as a form of sui generis surgical 'research', where the explicit goal of adopting such a definition is to bring about needed improvements in knowledge transfer and thereby benefit current and future patients.

  4. Abortion - surgical

    MedlinePlus

    Suction curettage; Surgical abortion; Elective abortion - surgical; Therapeutic abortion - surgical ... Surgical abortion involves dilating the opening to the uterus (cervix) and placing a small suction tube into the uterus. ...

  5. Optimizing molecular properties using a relative index of thermodynamic stability and global optimization techniques.

    PubMed

    Fournier, René; Mohareb, Amir

    2016-01-14

    We devised a global optimization (GO) strategy for optimizing molecular properties with respect to both geometry and chemical composition. A relative index of thermodynamic stability (RITS) is introduced to allow meaningful energy comparisons between different chemical species. We use the RITS by itself, or in combination with another calculated property, to create an objective function F to be minimized. Including the RITS in the definition of F ensures that the solutions have some degree of thermodynamic stability. We illustrate how the GO strategy works with three test applications, with F calculated in the framework of Kohn-Sham Density Functional Theory (KS-DFT) with the Perdew-Burke-Ernzerhof exchange-correlation. First, we searched the composition and configuration space of CmHnNpOq (m = 0-4, n = 0-10, p = 0-2, q = 0-2, and 2 ≤ m + n + p + q ≤ 12) for stable molecules. The GO discovered familiar molecules like N2, CO2, acetic acid, acetonitrile, ethane, and many others, after a small number (5000) of KS-DFT energy evaluations. Second, we carried out a GO of the geometry of CumSnn (+) (m = 1, 2 and n = 9-12). A single GO run produced the same low-energy structures found in an earlier study where each CumSnn (+) species had been optimized separately. Finally, we searched bimetallic clusters AmBn (3 ≤ m + n ≤ 6, A,B= Li, Na, Al, Cu, Ag, In, Sn, Pb) for species and configurations having a low RITS and large highest occupied Molecular Orbital (MO) to lowest unoccupied MO energy gap (Eg). We found seven bimetallic clusters with Eg > 1.5 eV. PMID:26772561

  6. Optimizing molecular properties using a relative index of thermodynamic stability and global optimization techniques

    NASA Astrophysics Data System (ADS)

    Fournier, René; Mohareb, Amir

    2016-01-01

    We devised a global optimization (GO) strategy for optimizing molecular properties with respect to both geometry and chemical composition. A relative index of thermodynamic stability (RITS) is introduced to allow meaningful energy comparisons between different chemical species. We use the RITS by itself, or in combination with another calculated property, to create an objective function F to be minimized. Including the RITS in the definition of F ensures that the solutions have some degree of thermodynamic stability. We illustrate how the GO strategy works with three test applications, with F calculated in the framework of Kohn-Sham Density Functional Theory (KS-DFT) with the Perdew-Burke-Ernzerhof exchange-correlation. First, we searched the composition and configuration space of CmHnNpOq (m = 0-4, n = 0-10, p = 0-2, q = 0-2, and 2 ≤ m + n + p + q ≤ 12) for stable molecules. The GO discovered familiar molecules like N2, CO2, acetic acid, acetonitrile, ethane, and many others, after a small number (5000) of KS-DFT energy evaluations. Second, we carried out a GO of the geometry of Cu m Snn + (m = 1, 2 and n = 9-12). A single GO run produced the same low-energy structures found in an earlier study where each Cu m S nn + species had been optimized separately. Finally, we searched bimetallic clusters AmBn (3 ≤ m + n ≤ 6, A,B= Li, Na, Al, Cu, Ag, In, Sn, Pb) for species and configurations having a low RITS and large highest occupied Molecular Orbital (MO) to lowest unoccupied MO energy gap (Eg). We found seven bimetallic clusters with Eg > 1.5 eV.

  7. Cost-Optimal Design of a 3-Phase Core Type Transformer by Gradient Search Technique

    NASA Astrophysics Data System (ADS)

    Basak, R.; Das, A.; Sensarma, A. K.; Sanyal, A. N.

    2014-04-01

    3-phase core type transformers are extensively used as power and distribution transformers in power system and their cost is a sizable proportion of the total system cost. Therefore they should be designed cost-optimally. The design methodology for reaching cost-optimality has been discussed in details by authors like Ramamoorty. It has also been discussed in brief in some of the text-books of electrical design. The paper gives a method for optimizing design, in presence of constraints specified by the customer and the regulatory authorities, through gradient search technique. The starting point has been chosen within the allowable parameter space the steepest decent path has been followed for convergence. The step length has been judiciously chosen and the program has been maneuvered to avoid local minimal points. The method appears to be best as its convergence is quickest amongst different optimizing techniques.

  8. Partial-transfer absorption imaging: a versatile technique for optimal imaging of ultracold gases.

    PubMed

    Ramanathan, Anand; Muniz, Sérgio R; Wright, Kevin C; Anderson, Russell P; Phillips, William D; Helmerson, Kristian; Campbell, Gretchen K

    2012-08-01

    Partial-transfer absorption imaging is a tool that enables optimal imaging of atomic clouds for a wide range of optical depths. In contrast to standard absorption imaging, the technique can be minimally destructive and can be used to obtain multiple successive images of the same sample. The technique involves transferring a small fraction of the sample from an initial internal atomic state to an auxiliary state and subsequently imaging that fraction absorptively on a cycling transition. The atoms remaining in the initial state are essentially unaffected. We demonstrate the technique, discuss its applicability, and compare its performance as a minimally destructive technique to that of phase-contrast imaging.

  9. Efficient optimization of batch distillation with chemical reaction using polynomial curve fitting techniques

    SciTech Connect

    Mujtaba, I.M.; Macchietto, S.

    1997-06-01

    A computationally efficient framework is presented for dynamic optimization of batch distillation where chemical reaction and separation take place simultaneously. An objective to maximize the conversion of the limiting reactant dynamic optimization problem (maximum conversion problem) is formulated for a representative system, and parametric solutions of the problem are obtained. Polynomial curve fitting techniques are then applied to the results of the dynamic optimization problem. These polynomials are used to formulate a nonlinear algebraic maximum profit problem which can be solved extremely efficiently using a nonlinear optimization solver. This provides an efficient framework which can be used for on-line optimization of batch distillation within scheduling programs for batch processes. The method can also be easily extended to nonreactive batch distillation and to nonconventional batch distillation columns.

  10. Scalable Clustering of High-Dimensional Data Technique Using SPCM with Ant Colony Optimization Intelligence

    PubMed Central

    Srinivasan, Thenmozhi; Palanisamy, Balasubramanie

    2015-01-01

    Clusters of high-dimensional data techniques are emerging, according to data noisy and poor quality challenges. This paper has been developed to cluster data using high-dimensional similarity based PCM (SPCM), with ant colony optimization intelligence which is effective in clustering nonspatial data without getting knowledge about cluster number from the user. The PCM becomes similarity based by using mountain method with it. Though this is efficient clustering, it is checked for optimization using ant colony algorithm with swarm intelligence. Thus the scalable clustering technique is obtained and the evaluation results are checked with synthetic datasets. PMID:26495413

  11. Gradient-based multiobjective optimization using a distance constraint technique and point replacement

    NASA Astrophysics Data System (ADS)

    Sato, Yuki; Izui, Kazuhiro; Yamada, Takayuki; Nishiwaki, Shinji

    2016-07-01

    This paper proposes techniques to improve the diversity of the searching points during the optimization process in an Aggregative Gradient-based Multiobjective Optimization (AGMO) method, so that well-distributed Pareto solutions are obtained. First to be discussed is a distance constraint technique, applied among searching points in the objective space when updating design variables, that maintains a minimum distance between the points. Next, a scheme is introduced that deals with updated points that violate the distance constraint, by deleting the offending points and introducing new points in areas of the objective space where searching points are sparsely distributed. Finally, the proposed method is applied to example problems to illustrate its effectiveness.

  12. A knowledge-based approach to improving optimization techniques in system planning

    NASA Technical Reports Server (NTRS)

    Momoh, J. A.; Zhang, Z. Z.

    1990-01-01

    A knowledge-based (KB) approach to improve mathematical programming techniques used in the system planning environment is presented. The KB system assists in selecting appropriate optimization algorithms, objective functions, constraints and parameters. The scheme is implemented by integrating symbolic computation of rules derived from operator and planner's experience and is used for generalized optimization packages. The KB optimization software package is capable of improving the overall planning process which includes correction of given violations. The method was demonstrated on a large scale power system discussed in the paper.

  13. Application of response surface techniques to helicopter rotor blade optimization procedure

    NASA Technical Reports Server (NTRS)

    Henderson, Joseph Lynn; Walsh, Joanne L.; Young, Katherine C.

    1995-01-01

    In multidisciplinary optimization problems, response surface techniques can be used to replace the complex analyses that define the objective function and/or constraints with simple functions, typically polynomials. In this work a response surface is applied to the design optimization of a helicopter rotor blade. In previous work, this problem has been formulated with a multilevel approach. Here, the response surface takes advantage of this decomposition and is used to replace the lower level, a structural optimization of the blade. Problems that were encountered and important considerations in applying the response surface are discussed. Preliminary results are also presented that illustrate the benefits of using the response surface.

  14. Particle size in fat graft retention: A review on the impact of harvesting technique in lipofilling surgical outcomes

    PubMed Central

    Gause, Trent M; Kling, Russell E; Sivak, Wesley N; Marra, Kacey G; Rubin, J Peter; Kokai, Lauren E

    2014-01-01

    Fat grafting popularity continues to rise among plastic surgeons. As a soft tissue filler, adipose tissue had many desirable attributes: it is easy to obtain, autologous, and may reintegrate into recipient sites. However, fat grafting is clinically plagued by unpredictable resorption rates, thus there is much interest in optimizing the procedure of fat grafting for consistent graft volumes. Fat harvesting, a part of fat transfer surgery, involves the removal of adipose tissue from the donor site. Different harvest procedures, such as whole fat excision or liposuction cannulas, result in a range of fat particle volumes, which may play a role in the cellular stability of grafts. The ideal harvesting technique and fat particle diameter is not currently known. This study aims to review the literature on the impact of fat particle size and clinical fat grafting outcomes, to present overarching conclusions, and to provide future directions for study. Current evidence supports excisional methods and larger bore cannulas to minimize cellular damage, preserve the native architecture, and maximize the number of cells within fat particles. PMID:26317051

  15. Configuration optimization and sensitivity comparison among thermal lens, photothermal deflection, and interference detection techniques

    NASA Astrophysics Data System (ADS)

    Li, Bincheng; Welsch, Eberhard

    1999-04-01

    Photothermal techniques, such as probe beam deflection and thermal lens detection, have been widely used for low absorption measurement, thermal characterization, and laser- induced damage detection of optical coatings. In specially configured photothermal techniques, the probe beam either detects the photothermally induced refractive index change inside the sample via propagation through the interacting region in the measured sample, or detects the surface displacement via reflection from the deformed surface. Usually, due to the very low absorption of the sample or/and the short interaction length, a very high sensitivity is required for such applications. It is therefore of importance to maximize the sensitivity for each measurement, by selecting appropriate detection scheme and optimizing the performance of the selected scheme. In this paper, we first maximize the sensitivity of these photothermal techniques by configuration optimization, then compare their maximum sensitivity. The applicability of the pulsed photothermal techniques to optical coating characterization is also discussed.

  16. A technique optimization protocol and the potential for dose reduction in digital mammography

    PubMed Central

    Ranger, Nicole T.; Lo, Joseph Y.; Samei, Ehsan

    2010-01-01

    Digital mammography requires revisiting techniques that have been optimized for prior screen∕film mammography systems. The objective of the study was to determine optimized radiographic technique for a digital mammography system and demonstrate the potential for dose reduction in comparison to the clinically established techniques based on screen- film. An objective figure of merit (FOM) was employed to evaluate a direct-conversion amorphous selenium (a-Se) FFDM system (Siemens Mammomat NovationDR, Siemens AG Medical Solutions, Erlangen, Germany) and was derived from the quotient of the squared signal-difference-to-noise ratio to mean glandular dose, for various combinations of technique factors and breast phantom configurations including kilovoltage settings (23–35 kVp), target∕filter combinations (Mo–Mo and W–Rh), breast-equivalent plastic in various thicknesses (2–8 cm) and densities (100% adipose, 50% adipose∕50% glandular, and 100% glandular), and simulated mass and calcification lesions. When using a W–Rh spectrum, the optimized FOM results for the simulated mass and calcification lesions showed highly consistent trends with kVp for each combination of breast density and thickness. The optimized kVp ranged from 26 kVp for 2 cm 100% adipose breasts to 30 kVp for 8 cm 100% glandular breasts. The use of the optimized W–Rh technique compared to standard Mo–Mo techniques provided dose savings ranging from 9% for 2 cm thick, 100% adipose breasts, to 63% for 6 cm thick, 100% glandular breasts, and for breasts with a 50% adipose∕50% glandular composition, from 12% for 2 cm thick breasts up to 57% for 8 cm thick breasts. PMID:20384232

  17. A technique optimization protocol and the potential for dose reduction in digital mammography

    SciTech Connect

    Ranger, Nicole T.; Lo, Joseph Y.; Samei, Ehsan

    2010-03-15

    Digital mammography requires revisiting techniques that have been optimized for prior screen/film mammography systems. The objective of the study was to determine optimized radiographic technique for a digital mammography system and demonstrate the potential for dose reduction in comparison to the clinically established techniques based on screen- film. An objective figure of merit (FOM) was employed to evaluate a direct-conversion amorphous selenium (a-Se) FFDM system (Siemens Mammomat Novation{sup DR}, Siemens AG Medical Solutions, Erlangen, Germany) and was derived from the quotient of the squared signal-difference-to-noise ratio to mean glandular dose, for various combinations of technique factors and breast phantom configurations including kilovoltage settings (23-35 kVp), target/filter combinations (Mo-Mo and W-Rh), breast-equivalent plastic in various thicknesses (2-8 cm) and densities (100% adipose, 50% adipose/50% glandular, and 100% glandular), and simulated mass and calcification lesions. When using a W-Rh spectrum, the optimized FOM results for the simulated mass and calcification lesions showed highly consistent trends with kVp for each combination of breast density and thickness. The optimized kVp ranged from 26 kVp for 2 cm 100% adipose breasts to 30 kVp for 8 cm 100% glandular breasts. The use of the optimized W-Rh technique compared to standard Mo-Mo techniques provided dose savings ranging from 9% for 2 cm thick, 100% adipose breasts, to 63% for 6 cm thick, 100% glandular breasts, and for breasts with a 50% adipose/50% glandular composition, from 12% for 2 cm thick breasts up to 57% for 8 cm thick breasts.

  18. A Preliminary Evaluation of an Optimizing Technique for Use in Selecting New School Locations.

    ERIC Educational Resources Information Center

    Hall, Fred L.

    During the past two decades, mathematical programing techniques have been widely utilized in the private sector for optimization studies in locating industrial plants, scheduling commodity flows, determining product mix, etc. However, their use in the public sector has been less extensive, partly because of the absence of a clear-cut profit motive…

  19. Optimum Design of Aluminum Beverage Can Ends Using Structural Optimization Techniques

    SciTech Connect

    Yamazaki, Koetsu; Watanabe, Masato; Itoh, Ryouiti; Han, Jing; Nishiyama, Sadao

    2005-08-05

    This paper has tried to apply the response surface approximate method in the structural optimization techniques to develop aluminum beverage can ends. Geometrical parameters of the end shell are selected as design variables. The analysis points in the design space are assigned using an orthogonal array in the design-of-experiment technique. Finite element analysis code is used to simulate the deforming behavior and to calculate buckling strength and central panel displacement of the end shell under internal pressure. On the basis of the numerical analysis results, the response surface of the buckling strength and panel growth are approximated in terms of the design variables. By using a numerical optimization program, the weight of the end shell is minimized subject to constraints of the buckling strength, panel growth suppression and other design requirements. A numerical example on 202 end shell optimization problem has been shown in this paper.

  20. Optimal regulator or conventional? Setup techniques for a model following simulator control system

    NASA Technical Reports Server (NTRS)

    Deets, D. A.

    1978-01-01

    Optimal regulator technique was compared for determining simulator control system gains with the conventional servo analysis approach. Practical considerations, associated with airborne motion simulation using a model-following system, provided the basis for comparison. The simulation fidelity specifications selected were important in evaluating the relative advantages of the two methods. Frequency responses for a JetStar aircraft following a roll mode model were calculated digitally to illustrate the various cases. A technique for generating forward loop lead in the optimal regulator model-following problem was developed which increases the flexibility of that approach. It appeared to be the only way in which the optimal regulator method could meet the fidelity specifications.

  1. Expert system and process optimization techniques for real-time monitoring and control of plasma processes

    NASA Astrophysics Data System (ADS)

    Cheng, Jie; Qian, Zhaogang; Irani, Keki B.; Etemad, Hossein; Elta, Michael E.

    1991-03-01

    To meet the ever-increasing demand of the rapidly-growing semiconductor manufacturing industry it is critical to have a comprehensive methodology integrating techniques for process optimization real-time monitoring and adaptive process control. To this end we have accomplished an integrated knowledge-based approach combining latest expert system technology machine learning method and traditional statistical process control (SPC) techniques. This knowledge-based approach is advantageous in that it makes it possible for the task of process optimization and adaptive control to be performed consistently and predictably. Furthermore this approach can be used to construct high-level and qualitative description of processes and thus make the process behavior easy to monitor predict and control. Two software packages RIST (Rule Induction and Statistical Testing) and KARSM (Knowledge Acquisition from Response Surface Methodology) have been developed and incorporated with two commercially available packages G2 (real-time expert system) and ULTRAMAX (a tool for sequential process optimization).

  2. Design of multifunctional structure with embedded electronic circuitry using composite laminate optimization techniques

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven; Crossley, William

    2008-10-01

    This research investigates the optimization of a multifunctional structure with embedded electronic circuitry, following traditional composite laminate optimization methods. A heavily 'de-featured' finite element model provides thermal and mechanical analyses of the structure. The model places point heat sources at the surface component locations, and the optimization problem enforces strain constraints at these locations. A simple problem seeks the least-mass I-beam whose shear web contains a simple circuit, subject to strength and strain constraints. A second problem finds the lowest mass unmanned aerial vehicle (UAV) wing box configuration containing embedded circuitry subject to strength, deflection and strain constraints under two load cases. Sequential unconstrained minimization techniques and sequential quadratic programming perform the optimization; combinatorial methods are computationally impractical. Despite the model de-featuring and the use of calculus-based methods, the problem requires significant computational effort. The surface-component strain constraints result in structures with more mass than those without surface components.

  3. Skating technique for the straights, based on the optimization of a simulation model.

    PubMed

    Allinger, T L; Van den Bogert, A J

    1997-02-01

    Although experimental data have been collected to determine the skating techniques of the fastest skaters in the world, the "ideal" skating technique has not been determined (i.e., stroke time, glide time, push-off velocity, and push-off direction). The purpose of this study was to determine the skating technique that results in the fastest steady-state speed on a straight-away using optimization of a simulation model. A dynamic model of a skater was developed that included anatomical and physiological constraints: leg length, instantaneous power, and average power of a skater. Results from the model demonstrate that a number of skating techniques can be used to achieve the same steady-state speed. Increasing the average power output of a skater raises the top skating speed and decreases the range of optimal skating techniques. Increasing instantaneous power output (i.e., increasing isometric strength) increases the range of techniques a skater may use for a given speed. In the future, this model can be applied to individual skaters to determine if changes in technique or if improvements in power production are necessary to improve their steady-state skating speed. This model may be adapted to skating sports, such as speed skating, in-line skating, hockey, and cross-country skiing.

  4. Techniques for optimal crop selection in a controlled ecological life support system

    NASA Technical Reports Server (NTRS)

    Mccormack, Ann; Finn, Cory; Dunsky, Betsy

    1993-01-01

    A Controlled Ecological Life Support System (CELSS) utilizes a plant's natural ability to regenerate air and water while being grown as a food source in a closed life support system. Current plant research is directed toward obtaining quantitative empirical data on the regenerative ability of each species of plant and the system volume and power requirements. Two techniques were adapted to optimize crop species selection while at the same time minimizing the system volume and power requirements. Each allows the level of life support supplied by the plants to be selected, as well as other system parameters. The first technique uses decision analysis in the form of a spreadsheet. The second method, which is used as a comparison with and validation of the first, utilizes standard design optimization techniques. Simple models of plant processes are used in the development of these methods.

  5. Techniques for optimal crop selection in a controlled ecological life support system

    NASA Technical Reports Server (NTRS)

    Mccormack, Ann; Finn, Cory; Dunsky, Betsy

    1992-01-01

    A Controlled Ecological Life Support System (CELSS) utilizes a plant's natural ability to regenerate air and water while being grown as a food source in a closed life support system. Current plant research is directed toward obtaining quantitative empirical data on the regenerative ability of each species of plant and the system volume and power requirements. Two techniques were adapted to optimize crop species selection while at the same time minimizing the system volume and power requirements. Each allows the level of life support supplied by the plants to be selected, as well as other system parameters. The first technique uses decision analysis in the form of a spreadsheet. The second method, which is used as a comparison with and validation of the first, utilizes standard design optimization techniques. Simple models of plant processes are used in the development of these methods.

  6. Feedback control for fuel-optimal descents using singular perturbation techniques

    NASA Technical Reports Server (NTRS)

    Price, D. B.

    1984-01-01

    In response to rising fuel costs and reduced profit margins for the airline companies, the optimization of the paths flown by transport aircraft has been considered. It was found that application of optimal control theory to the considered problem can result in savings in fuel, time, and direct operating costs. The best solution to the aircraft trajectory problem is an onboard real-time feedback control law. The present paper presents a technique which shows promise of becoming a part of a complete solution. The application of singular perturbation techniques to the problem is discussed, taking into account the benefits and some problems associated with them. A different technique for handling the descent part of a trajectory is also discussed.

  7. Implant surgical guides: From the past to the present

    PubMed Central

    Ramasamy, Manikandan; Giri; Raja, Ramesh; Subramonian; Karthik; Narendrakumar, Rachuri

    2013-01-01

    Advent of osseointegration has rapidly led to use of dental implants over recent years. Implant complications are often inadvertent sequelae of improper diagnosis, treatment planning, surgical method, and placement. This can be overcome by using surgical guides for implant positioning. Although conventionally made surgical guide are used, the clinical outcome is often unpredictable, and even if the implants are well placed, the location and deviation of the implants may not meet the optimal prosthodontic requirements. High accuracy in planning and execution of surgical procedures is important in securing a high success rate without causing iatrogenic damage. This can be achieved by computed tomography, 3D implant planning software, image-guided template production techniques, and computer-aided surgery. This article evaluates about the various systems of conventionally made surgical guide using radiograph and also the newer computer generated surgical guide in detail. PMID:23946587

  8. Evolutionary techniques for sensor networks energy optimization in marine environmental monitoring

    NASA Astrophysics Data System (ADS)

    Grimaccia, Francesco; Johnstone, Ron; Mussetta, Marco; Pirisi, Andrea; Zich, Riccardo E.

    2012-10-01

    The sustainable management of coastal and offshore ecosystems, such as for example coral reef environments, requires the collection of accurate data across various temporal and spatial scales. Accordingly, monitoring systems are seen as central tools for ecosystem-based environmental management, helping on one hand to accurately describe the water column and substrate biophysical properties, and on the other hand to correctly steer sustainability policies by providing timely and useful information to decision-makers. A robust and intelligent sensor network that can adjust and be adapted to different and changing environmental or management demands would revolutionize our capacity to wove accurately model, predict, and manage human impacts on our coastal, marine, and other similar environments. In this paper advanced evolutionary techniques are applied to optimize the design of an innovative energy harvesting device for marine applications. The authors implement an enhanced technique in order to exploit in the most effective way the uniqueness and peculiarities of two classical optimization approaches, Particle Swarm Optimization and Genetic Algorithms. Here, this hybrid procedure is applied to a power buoy designed for marine environmental monitoring applications in order to optimize the recovered energy from sea-wave, by selecting the optimal device configuration.

  9. An approximation technique for computing optimal fixed-order controllers for infinite-dimensional systems

    NASA Technical Reports Server (NTRS)

    Bernstein, Dennis S.; Rosen, I. Gary

    1988-01-01

    The finite-dimensional approximation of the infinite-dimensional Bernstein/Hyland optimal projection theory is investigated analytically. The approach yields fixed-finite-order controllers which are optimal with respect to high-order approximating finite-dimensional plant models. The technique is illustrated by computing a sequence of first-order controllers for a one-dimensional SISO parabolic (heat/diffusion) system using a spline-based Ritz-Galerkin finite-element approximation. The numerical studies indicate convergence of the feedback gains with less than 2-percent performance degradation over full-order LQG controllers.

  10. Influence of robust optimization in intensity-modulated proton therapy with different dose delivery techniques

    SciTech Connect

    Liu Wei; Li Yupeng; Li Xiaoqiang; Cao Wenhua; Zhang Xiaodong

    2012-06-15

    Purpose: The distal edge tracking (DET) technique in intensity-modulated proton therapy (IMPT) allows for high energy efficiency, fast and simple delivery, and simple inverse treatment planning; however, it is highly sensitive to uncertainties. In this study, the authors explored the application of DET in IMPT (IMPT-DET) and conducted robust optimization of IMPT-DET to see if the planning technique's sensitivity to uncertainties was reduced. They also compared conventional and robust optimization of IMPT-DET with three-dimensional IMPT (IMPT-3D) to gain understanding about how plan robustness is achieved. Methods: They compared the robustness of IMPT-DET and IMPT-3D plans to uncertainties by analyzing plans created for a typical prostate cancer case and a base of skull (BOS) cancer case (using data for patients who had undergone proton therapy at our institution). Spots with the highest and second highest energy layers were chosen so that the Bragg peak would be at the distal edge of the targets in IMPT-DET using 36 equally spaced angle beams; in IMPT-3D, 3 beams with angles chosen by a beam angle optimization algorithm were planned. Dose contributions for a number of range and setup uncertainties were calculated, and a worst-case robust optimization was performed. A robust quantification technique was used to evaluate the plans' sensitivity to uncertainties. Results: With no uncertainties considered, the DET is less robust to uncertainties than is the 3D method but offers better normal tissue protection. With robust optimization to account for range and setup uncertainties, robust optimization can improve the robustness of IMPT plans to uncertainties; however, our findings show the extent of improvement varies. Conclusions: IMPT's sensitivity to uncertainties can be improved by using robust optimization. They found two possible mechanisms that made improvements possible: (1) a localized single-field uniform dose distribution (LSFUD) mechanism, in which the

  11. New surgical techniques and surgical site infections.

    PubMed Central

    Gordon, S. M.

    2001-01-01

    Technologic advances in surgery include a trend toward less invasive procedures, driven by potential benefits to patients and by health-care economics. These less invasive procedures provide infection control personnel opportunities for direct involvement in outcomes measurement. PMID:11294710

  12. Geometric parameter analysis to predetermine optimal radiosurgery technique for the treatment of arteriovenous malformation

    SciTech Connect

    Mestrovic, Ante . E-mail: amestrovic@bccancer.bc.ca; Clark, Brenda G.

    2005-11-01

    Purpose: To develop a method of predicting the values of dose distribution parameters of different radiosurgery techniques for treatment of arteriovenous malformation (AVM) based on internal geometric parameters. Methods and Materials: For each of 18 previously treated AVM patients, four treatment plans were created: circular collimator arcs, dynamic conformal arcs, fixed conformal fields, and intensity-modulated radiosurgery. An algorithm was developed to characterize the target and critical structure shape complexity and the position of the critical structures with respect to the target. Multiple regression was employed to establish the correlation between the internal geometric parameters and the dose distribution for different treatment techniques. The results from the model were applied to predict the dosimetric outcomes of different radiosurgery techniques and select the optimal radiosurgery technique for a number of AVM patients. Results: Several internal geometric parameters showing statistically significant correlation (p < 0.05) with the treatment planning results for each technique were identified. The target volume and the average minimum distance between the target and the critical structures were the most effective predictors for normal tissue dose distribution. The structure overlap volume with the target and the mean distance between the target and the critical structure were the most effective predictors for critical structure dose distribution. The predicted values of dose distribution parameters of different radiosurgery techniques were in close agreement with the original data. Conclusions: A statistical model has been described that successfully predicts the values of dose distribution parameters of different radiosurgery techniques and may be used to predetermine the optimal technique on a patient-to-patient basis.

  13. Optimization of brushless direct current motor design using an intelligent technique.

    PubMed

    Shabanian, Alireza; Tousiwas, Armin Amini Poustchi; Pourmandi, Massoud; Khormali, Aminollah; Ataei, Abdolhay

    2015-07-01

    This paper presents a method for the optimal design of a slotless permanent magnet brushless DC (BLDC) motor with surface mounted magnets using an improved bee algorithm (IBA). The characteristics of the motor are expressed as functions of motor geometries. The objective function is a combination of losses, volume and cost to be minimized simultaneously. This method is based on the capability of swarm-based algorithms in finding the optimal solution. One sample case is used to illustrate the performance of the design approach and optimization technique. The IBA has a better performance and speed of convergence compared with bee algorithm (BA). Simulation results show that the proposed method has a very high/efficient performance.

  14. Integration of artificial intelligence and numerical optimization techniques for the design of complex aerospace systems

    SciTech Connect

    Tong, S.S.; Powell, D.; Goel, S. GE Consulting Services, Albany, NY )

    1992-02-01

    A new software system called Engineous combines artificial intelligence and numerical methods for the design and optimization of complex aerospace systems. Engineous combines the advanced computational techniques of genetic algorithms, expert systems, and object-oriented programming with the conventional methods of numerical optimization and simulated annealing to create a design optimization environment that can be applied to computational models in various disciplines. Engineous has produced designs with higher predicted performance gains that current manual design processes - on average a 10-to-1 reduction of turnaround time - and has yielded new insights into product design. It has been applied to the aerodynamic preliminary design of an aircraft engine turbine, concurrent aerodynamic and mechanical preliminary design of an aircraft engine turbine blade and disk, a space superconductor generator, a satellite power converter, and a nuclear-powered satellite reactor and shield. 23 refs.

  15. The surgical management of necrotizing enterocolitis.

    PubMed

    Kastenberg, Zachary J; Sylvester, Karl G

    2013-03-01

    Necrotizing enterocolitis (NEC), a common cause of neonatal morbidity and mortality, is strongly associated with prematurity and typically occurs following initiation of enteral feeds. Mild NEC is adequately treated by cessation of enteral feeding, empiric antibiotics, and supportive care. Approximately 50% of affected infants will develop progressive intestinal necrosis requiring urgent operation. Several surgical techniques have been described, but there is no clear survival benefit for any single operative approach. While debate continues regarding the optimal surgical management for infants with severe NEC, future progress will likely depend on the development of improved diagnostic tools and preventive therapies. PMID:23415269

  16. Method and apparatus for optimizing operation of a power generating plant using artificial intelligence techniques

    DOEpatents

    Wroblewski, David; Katrompas, Alexander M.; Parikh, Neel J.

    2009-09-01

    A method and apparatus for optimizing the operation of a power generating plant using artificial intelligence techniques. One or more decisions D are determined for at least one consecutive time increment, where at least one of the decisions D is associated with a discrete variable for the operation of a power plant device in the power generating plant. In an illustrated embodiment, the power plant device is a soot cleaning device associated with a boiler.

  17. Parametric Studies and Optimization of Eddy Current Techniques through Computer Modeling

    SciTech Connect

    Todorov, E. I.

    2007-03-21

    The paper demonstrates the use of computer models for parametric studies and optimization of surface and subsurface eddy current techniques. The study with high-frequency probe investigates the effect of eddy current frequency and probe shape on the detectability of flaws in the steel substrate. The low-frequency sliding probe study addresses the effect of conductivity between the fastener and the hole, frequency and coil separation distance on detectability of flaws in subsurface layers.

  18. A technique for calculating optimal Hohmann transfers with simultaneous plane and node rotations

    NASA Astrophysics Data System (ADS)

    Rogers, Christopher F.

    This analysis presents eight nonlinear coupled equations whose solution provides sufficient information to characterize an optimal Hohmann transfer with simultaneous plane and node rotations. It also presents auxiliary equations which help provide other information of interest. The derivations utilize spherical geometry but otherwise deal very directly with the transfer geometry and thereby remain conceptually simple. The assumptions include initial and final circular orbits and impulsive burns. Numerical results illustrate the technique.

  19. An adaptive image enhancement technique by combining cuckoo search and particle swarm optimization algorithm.

    PubMed

    Ye, Zhiwei; Wang, Mingwei; Hu, Zhengbing; Liu, Wei

    2015-01-01

    Image enhancement is an important procedure of image processing and analysis. This paper presents a new technique using a modified measure and blending of cuckoo search and particle swarm optimization (CS-PSO) for low contrast images to enhance image adaptively. In this way, contrast enhancement is obtained by global transformation of the input intensities; it employs incomplete Beta function as the transformation function and a novel criterion for measuring image quality considering three factors which are threshold, entropy value, and gray-level probability density of the image. The enhancement process is a nonlinear optimization problem with several constraints. CS-PSO is utilized to maximize the objective fitness criterion in order to enhance the contrast and detail in an image by adapting the parameters of a novel extension to a local enhancement technique. The performance of the proposed method has been compared with other existing techniques such as linear contrast stretching, histogram equalization, and evolutionary computing based image enhancement methods like backtracking search algorithm, differential search algorithm, genetic algorithm, and particle swarm optimization in terms of processing time and image quality. Experimental results demonstrate that the proposed method is robust and adaptive and exhibits the better performance than other methods involved in the paper. PMID:25784928

  20. The L_infinity constrained global optimal histogram equalization technique for real time imaging

    NASA Astrophysics Data System (ADS)

    Ren, Qiongwei; Niu, Yi; Liu, Lin; Jiao, Yang; Shi, Guangming

    2015-08-01

    Although the current imaging sensors can achieve 12 or higher precision, the current display devices and the commonly used digital image formats are still only 8 bits. This mismatch causes significant waste of the sensor precision and loss of information when storing and displaying the images. For better usage of the precision-budget, tone mapping operators have to be used to map the high-precision data into low-precision digital images adaptively. In this paper, the classic histogram equalization tone mapping operator is reexamined in the sense of optimization. We point out that the traditional histogram equalization technique and its variants are fundamentally improper by suffering from local optimum problems. To overcome this drawback, we remodel the histogram equalization tone mapping task based on graphic theory which achieves the global optimal solutions. Another advantage of the graphic-based modeling is that the tone-continuity is also modeled as a vital constraint in our approach which suppress the annoying boundary artifacts of the traditional approaches. In addition, we propose a novel dynamic programming technique to solve the histogram equalization problem in real time. Experimental results shows that the proposed tone-preserved global optimal histogram equalization technique outperforms the traditional approaches by exhibiting more subtle details in the foreground while preserving the smoothness of the background.

  1. Optimization of liquid overlay technique to formulate heterogenic 3D co-cultures models.

    PubMed

    Costa, Elisabete C; Gaspar, Vítor M; Coutinho, Paula; Correia, Ilídio J

    2014-08-01

    Three-dimensional (3D) cell culture models of solid tumors are currently having a tremendous impact in the in vitro screening of candidate anti-tumoral therapies. These 3D models provide more reliable results than those provided by standard 2D in vitro cell cultures. However, 3D manufacturing techniques need to be further optimized in order to increase the robustness of these models and provide data that can be properly correlated with the in vivo situation. Therefore, in the present study the parameters used for producing multicellular tumor spheroids (MCTS) by liquid overlay technique (LOT) were optimized in order to produce heterogeneous cellular agglomerates comprised of cancer cells and stromal cells, during long periods. Spheroids were produced under highly controlled conditions, namely: (i) agarose coatings; (ii) horizontal stirring, and (iii) a known initial cell number. The simultaneous optimization of these parameters promoted the assembly of 3D characteristic cellular organization similar to that found in the in vivo solid tumors. Such improvements in the LOT technique promoted the assembly of highly reproducible, individual 3D spheroids, with a low cost of production and that can be used for future in vitro drug screening assays.

  2. An adaptive image enhancement technique by combining cuckoo search and particle swarm optimization algorithm.

    PubMed

    Ye, Zhiwei; Wang, Mingwei; Hu, Zhengbing; Liu, Wei

    2015-01-01

    Image enhancement is an important procedure of image processing and analysis. This paper presents a new technique using a modified measure and blending of cuckoo search and particle swarm optimization (CS-PSO) for low contrast images to enhance image adaptively. In this way, contrast enhancement is obtained by global transformation of the input intensities; it employs incomplete Beta function as the transformation function and a novel criterion for measuring image quality considering three factors which are threshold, entropy value, and gray-level probability density of the image. The enhancement process is a nonlinear optimization problem with several constraints. CS-PSO is utilized to maximize the objective fitness criterion in order to enhance the contrast and detail in an image by adapting the parameters of a novel extension to a local enhancement technique. The performance of the proposed method has been compared with other existing techniques such as linear contrast stretching, histogram equalization, and evolutionary computing based image enhancement methods like backtracking search algorithm, differential search algorithm, genetic algorithm, and particle swarm optimization in terms of processing time and image quality. Experimental results demonstrate that the proposed method is robust and adaptive and exhibits the better performance than other methods involved in the paper.

  3. An Adaptive Image Enhancement Technique by Combining Cuckoo Search and Particle Swarm Optimization Algorithm

    PubMed Central

    Ye, Zhiwei; Wang, Mingwei; Hu, Zhengbing; Liu, Wei

    2015-01-01

    Image enhancement is an important procedure of image processing and analysis. This paper presents a new technique using a modified measure and blending of cuckoo search and particle swarm optimization (CS-PSO) for low contrast images to enhance image adaptively. In this way, contrast enhancement is obtained by global transformation of the input intensities; it employs incomplete Beta function as the transformation function and a novel criterion for measuring image quality considering three factors which are threshold, entropy value, and gray-level probability density of the image. The enhancement process is a nonlinear optimization problem with several constraints. CS-PSO is utilized to maximize the objective fitness criterion in order to enhance the contrast and detail in an image by adapting the parameters of a novel extension to a local enhancement technique. The performance of the proposed method has been compared with other existing techniques such as linear contrast stretching, histogram equalization, and evolutionary computing based image enhancement methods like backtracking search algorithm, differential search algorithm, genetic algorithm, and particle swarm optimization in terms of processing time and image quality. Experimental results demonstrate that the proposed method is robust and adaptive and exhibits the better performance than other methods involved in the paper. PMID:25784928

  4. Combinatorial techniques to efficiently investigate and optimize organic thin film processing and properties.

    PubMed

    Wieberger, Florian; Kolb, Tristan; Neuber, Christian; Ober, Christopher K; Schmidt, Hans-Werner

    2013-04-08

    In this article we present several developed and improved combinatorial techniques to optimize processing conditions and material properties of organic thin films. The combinatorial approach allows investigations of multi-variable dependencies and is the perfect tool to investigate organic thin films regarding their high performance purposes. In this context we develop and establish the reliable preparation of gradients of material composition, temperature, exposure, and immersion time. Furthermore we demonstrate the smart application of combinations of composition and processing gradients to create combinatorial libraries. First a binary combinatorial library is created by applying two gradients perpendicular to each other. A third gradient is carried out in very small areas and arranged matrix-like over the entire binary combinatorial library resulting in a ternary combinatorial library. Ternary combinatorial libraries allow identifying precise trends for the optimization of multi-variable dependent processes which is demonstrated on the lithographic patterning process. Here we verify conclusively the strong interaction and thus the interdependency of variables in the preparation and properties of complex organic thin film systems. The established gradient preparation techniques are not limited to lithographic patterning. It is possible to utilize and transfer the reported combinatorial techniques to other multi-variable dependent processes and to investigate and optimize thin film layers and devices for optical, electro-optical, and electronic applications.

  5. Enterocutaneous Fistula: Different Surgical Intervention Techniques for Closure along with Comparative Evaluation of Aluminum Paint, Karaya Gum (Hollister) and Gum Acacia for Peristomal Skin Care

    PubMed Central

    Namrata; Ahmad, Shabi

    2015-01-01

    Introduction Gastrointestinal fistulas are serious complications and are associated with high morbidity and mortality rates. In majority of the patients, fistulas are treatable. However, the treatment is very complex and often multiple therapies are required. These highly beneficial treatment options which could shorten fistula closure time also result in considerable hospital cost savings. Aim This study was planned to study aetiology, clinical presentation, morbidity and mortality of enterocutaneous fistula and to evaluate the different surgical intervention techniques for closure of enterocutaneous fistula along with a comparative evaluation of different techniques for management of peristomal skin with special emphasis on aluminum paint, Karaya gum (Hollister) and Gum Acacia. Materials and Methods This prospective observational study was conducted in the Department of Surgery, M.L.N. Medical College, Allahabad and its associated hospital (S.R.N. Hospital, Allahabad) for a period of five years. Results Majority of enterocutaneous fistula were of small bowel and medium output fistulas (500-1000 ml/24hours). Most of the patients were treated with conservative treatment as compared to surgical intervention. Large bowel fistula has maximum spontaneous closure rate compare to small bowel and duodenum. Number of orifice whether single or multiple does not appear to play statistically significant role in spontaneous closure of fistula. Serum Albumin is a significantly important predictor of spontaneous fistula closure and mortality. Surgical management appeared to be the treatment of choice in distal bowel fistula. The application of karaya gum (Hollister kit), Gum Acacia and Aluminum Paint gave similar outcome. Conclusion Postoperative fistulas are the most common aetiology of enterocutaneous fistula and various factors do play role in management. Peristomal skin care done with Karaya Gum, Gum Acacia and Aluminum Paint has almost equal efficiency in management of skin

  6. Estimation of the stapes-bone thickness in the stapedotomy surgical procedure using a machine-learning technique.

    PubMed

    Kaburlasos, V G; Petridis, V; Brett, P N; Baker, D A

    1999-12-01

    Stapedotomy is a surgical procedure aimed at the treatment of hearing impairment due to otosclerosis. The treatment consists of drilling a hole through the stapes bone in the inner ear in order to insert a prosthesis. Safety precautions require knowledge of the nonmeasurable stapes thickness. The technical goal herein has been the design of high-level controls for an intelligent mechatronics drilling tool in order to enable the estimation of stapes thickness from measurable drilling data. The goal has been met by learning a map between drilling features, hence no model of the physical system has been necessary. Learning has been achieved as explained in this paper by a scheme, namely the d-sigma Fuzzy Lattice Neurocomputing (d sigma-FLN) scheme for classification, within the framework of fuzzy lattices. The successful application of the d sigma-FLN scheme is demonstrated in estimating the thickness of a stapes bone "on-line" using drilling data obtained experimentally in the laboratory.

  7. Optimized swimmer tracking system by a dynamic fusion of correlation and color histogram techniques

    NASA Astrophysics Data System (ADS)

    Benarab, D.; Napoléon, T.; Alfalou, A.; Verney, A.; Hellard, P.

    2015-12-01

    To design a robust swimmer tracking system, we took into account two well-known tracking techniques: the nonlinear joint transform correlation (NL-JTC) and the color histogram. The two techniques perform comparably well, yet they both have substantial limitations. Interestingly, they also seem to show some complementarity. The correlation technique yields accurate detection but is sensitive to rotation, scale and contour deformation, whereas the color histogram technique is robust for rotation and contour deformation but shows low accuracy and is highly sensitive to luminosity and confusing background colors. These observations suggested the possibility of a dynamic fusion of the correlation plane and the color scores map. Before this fusion, two steps are required. First is the extraction of a sub-plane of correlation that describes the similarity between the reference and target images. This sub-plane has the same size as the color scores map but they have different interval values. Thus, the second step is required which is the normalization of the planes in the same interval so they can be fused. In order to determine the benefits of this fusion technique, first, we tested it on a synthetic image containing different forms with different colors. We thus were able to optimize the correlation plane and color histogram techniques before applying our fusion technique to real videos of swimmers in international competitions. Last, a comparative study of the dynamic fusion technique and the two classical techniques was carried out to demonstrate the efficacy of the proposed technique. The criteria of comparison were the tracking percentage, the peak to correlation energy (PCE), which evaluated the sharpness of the peak (accuracy), and the local standard deviation (Local-STD), which assessed the noise in the planes (robustness).

  8. Retrograde Approach Using Surgical Cutdown Technique for Limb Salvage in a Case of Critical Limb Ischemia With Severely Calcified Tibial Occlusive Disease.

    PubMed

    Shiraki, Tatsuya; Iida, Osamu; Suemitsu, Kotaro; Tsuji, Yoriko; Uematsu, Masaaki

    2016-05-01

    We here report a successful angioplasty for tibial artery occlusion using direct tibial puncture and subsequent retrograde approach under surgical cutdown technique. An 82-year-old man with ulcer/gangrene in first and second digits was referred to our hospital for endovascular therapy (EVT) of lower extremity ischemia. Diagnostic angiogram revealed anterior tibial artery (ATA) occlusion with severe calcification. Subintimal angioplasty was attempted using a 0.014-inch hydrophilic guidewire but was unsuccessful. A retrograde approach was subsequently attempted for ATA recanalization. However, because of severe calcification of dorsal pedis artery (DPA), percutaneous distal puncture was also unsuccessful. Direct puncture under surgical cutdown technique for DPA was subsequently performed and was successful. A 0.014-inch hydrophilic wire was advanced in retrograde fashion across the ATA occlusion and was used to access the microcatheter positioned at the proximal ATA via antegrade approach. Angioplasty of the ATA occlusion was performed using a 2.5-/3.0-mm tapered balloon. Completion angiogram revealed restoration of flow without dissection. Skin perfusion pressure was dramatically improved. Complete wound healing was achieved 5 months after EVT. PMID:27207678

  9. Dynamic optimization of distributed biological systems using robust and efficient numerical techniques

    PubMed Central

    2012-01-01

    Background Systems biology allows the analysis of biological systems behavior under different conditions through in silico experimentation. The possibility of perturbing biological systems in different manners calls for the design of perturbations to achieve particular goals. Examples would include, the design of a chemical stimulation to maximize the amplitude of a given cellular signal or to achieve a desired pattern in pattern formation systems, etc. Such design problems can be mathematically formulated as dynamic optimization problems which are particularly challenging when the system is described by partial differential equations. This work addresses the numerical solution of such dynamic optimization problems for spatially distributed biological systems. The usual nonlinear and large scale nature of the mathematical models related to this class of systems and the presence of constraints on the optimization problems, impose a number of difficulties, such as the presence of suboptimal solutions, which call for robust and efficient numerical techniques. Results Here, the use of a control vector parameterization approach combined with efficient and robust hybrid global optimization methods and a reduced order model methodology is proposed. The capabilities of this strategy are illustrated considering the solution of a two challenging problems: bacterial chemotaxis and the FitzHugh-Nagumo model. Conclusions In the process of chemotaxis the objective was to efficiently compute the time-varying optimal concentration of chemotractant in one of the spatial boundaries in order to achieve predefined cell distribution profiles. Results are in agreement with those previously published in the literature. The FitzHugh-Nagumo problem is also efficiently solved and it illustrates very well how dynamic optimization may be used to force a system to evolve from an undesired to a desired pattern with a reduced number of actuators. The presented methodology can be used for the

  10. [Initial management of advanced ovarian cancer: What radiological, pathological and surgical information are important for optimal therapeutic strategy?].

    PubMed

    Heudel, Pierre-Etienne; Selle, Frédéric; Morice, Philippe; Rouzier, Roman; Taieb, Sophie; Devouassoux-Shisheboran, Mojgan; Genestie, Catherine; Balleyguier, Corinne; Ray-Coquard, Isabelle

    2015-09-01

    Because the majority of patients present advanced disease at diagnosis, the management of epithelial ovarian cancer needs specialist multidisciplinary teamwork. Expertise in surgery, chemotherapy, imaging and histopathology is essential to achieve optimum outcomes. Computed tomography scans are routinely used to determine the extent of disease and to aid in surgical planning. The histologic classification is crucial to plan the best therapeutic strategy and to define the prognosis of disease. Pathological prognostic factors, such as degree of differentiation, FIGO-stage, and histological type have to be described. This report is fundamental to assessing prognosis and selection of appropriate treatment strategy. An adequate staging procedure is an extensive staging by an experienced gynecological oncologist, exploring the entire upper abdomen, and the pelvic and para-aortic lymph node regions to define the Peritoneal Cancer Index (PCI). The final assessment is the completeness of cytoreduction (CC) score, which is an assessment of residual disease after a maximal surgical effort. Initial management of advanced ovarian cancer is best provided by a specialist multidisciplinary team, including a radiologist, a pathologist, a gynecologic oncologist and a medical oncologist.

  11. Talus fractures: surgical principles.

    PubMed

    Rush, Shannon M; Jennings, Meagan; Hamilton, Graham A

    2009-01-01

    Surgical treatment of talus fractures can challenge even the most skilled foot and ankle surgeon. Complicated fracture patterns combined with joint dislocation of variable degrees require accurate assessment, sound understanding of principles of fracture care, and broad command of internal fixation techniques needed for successful surgical care. Elimination of unnecessary soft tissue dissection, a low threshold for surgical reduction, liberal use of malleolar osteotomy to expose body fracture, and detailed attention to fracture reduction and joint alignment are critical to the success of treatment. Even with the best surgical care complications are common and seem to correlate with injury severity and open injuries. PMID:19121756

  12. Does the piezoelectric surgical technique produce fewer postoperative sequelae after lower third molar surgery than conventional rotary instruments? A systematic review and meta analysis.

    PubMed

    Al-Moraissi, E A; Elmansi, Y A; Al-Sharaee, Y A; Alrmali, A E; Alkhutari, A S

    2016-03-01

    A systematic review and meta-analysis was conducted to answer the clinical question "Does the piezoelectric surgical technique produce fewer postoperative sequelae after lower third molar surgery than conventional rotary instruments?" A systematic and electronic search of several databases with specific key words, a reference search, and a manual search were performed from respective dates of inception through November 2014. The inclusion criteria were clinical human studies, including randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies, with the aim of comparing the piezoelectric surgical osteotomy technique to the standard rotary instrument technique in lower third molar surgery. Postoperative sequelae (oedema, trismus, and pain), the total number of analgesics taken, and the duration of surgery were analyzed. A total of nine articles were included, six RCTs, two CCTs, and one retrospective study. Six studies had a low risk of bias and three had a moderate risk of bias. A statistically significant difference was found between piezoelectric surgery and conventional rotary instrument surgery for lower third molar extraction with regard to postoperative sequelae (oedema, trismus, and pain) and the total number of analgesics taken (P=0.0001, P=0.0001, P<0.00001, and P<0.0001, respectively). However, a statistically significant increased surgery time was required in the piezoelectric osteotomy group (P<0.00001). The results of the meta-analysis showed that piezoelectric surgery significantly reduced the occurrence of postoperative sequelae (oedema, trismus, and pain) and the total number of analgesics taken compared to the conventional rotary instrument technique in lower third molar surgery, but required a longer surgery time.

  13. Determination of the optimal tolerance for MLC positioning in sliding window and VMAT techniques

    SciTech Connect

    Hernandez, V. Abella, R.; Calvo, J. F.; Jurado-Bruggemann, D.; Sancho, I.; Carrasco, P.

    2015-04-15

    Purpose: Several authors have recommended a 2 mm tolerance for multileaf collimator (MLC) positioning in sliding window treatments. In volumetric modulated arc therapy (VMAT) treatments, however, the optimal tolerance for MLC positioning remains unknown. In this paper, the authors present the results of a multicenter study to determine the optimal tolerance for both techniques. Methods: The procedure used is based on dynalog file analysis. The study was carried out using seven Varian linear accelerators from five different centers. Dynalogs were collected from over 100 000 clinical treatments and in-house software was used to compute the number of tolerance faults as a function of the user-defined tolerance. Thus, the optimal value for this tolerance, defined as the lowest achievable value, was investigated. Results: Dynalog files accurately predict the number of tolerance faults as a function of the tolerance value, especially for low fault incidences. All MLCs behaved similarly and the Millennium120 and the HD120 models yielded comparable results. In sliding window techniques, the number of beams with an incidence of hold-offs >1% rapidly decreases for a tolerance of 1.5 mm. In VMAT techniques, the number of tolerance faults sharply drops for tolerances around 2 mm. For a tolerance of 2.5 mm, less than 0.1% of the VMAT arcs presented tolerance faults. Conclusions: Dynalog analysis provides a feasible method for investigating the optimal tolerance for MLC positioning in dynamic fields. In sliding window treatments, the tolerance of 2 mm was found to be adequate, although it can be reduced to 1.5 mm. In VMAT treatments, the typically used 5 mm tolerance is excessively high. Instead, a tolerance of 2.5 mm is recommended.

  14. Optimizing charge breeding techniques for ISOL facilities in Europe: Conclusions from the EMILIE project.

    PubMed

    Delahaye, P; Galatà, A; Angot, J; Cam, J F; Traykov, E; Ban, G; Celona, L; Choinski, J; Gmaj, P; Jardin, P; Koivisto, H; Kolhinen, V; Lamy, T; Maunoury, L; Patti, G; Thuillier, T; Tarvainen, O; Vondrasek, R; Wenander, F

    2016-02-01

    The present paper summarizes the results obtained from the past few years in the framework of the Enhanced Multi-Ionization of short-Lived Isotopes for Eurisol (EMILIE) project. The EMILIE project aims at improving the charge breeding techniques with both Electron Cyclotron Resonance Ion Sources (ECRIS) and Electron Beam Ion Sources (EBISs) for European Radioactive Ion Beam (RIB) facilities. Within EMILIE, an original technique for debunching the beam from EBIS charge breeders is being developed, for making an optimal use of the capabilities of CW post-accelerators of the future facilities. Such a debunching technique should eventually resolve duty cycle and time structure issues which presently complicate the data-acquisition of experiments. The results of the first tests of this technique are reported here. In comparison with charge breeding with an EBIS, the ECRIS technique had lower performance in efficiency and attainable charge state for metallic ion beams and also suffered from issues related to beam contamination. In recent years, improvements have been made which significantly reduce the differences between the two techniques, making ECRIS charge breeding more attractive especially for CW machines producing intense beams. Upgraded versions of the Phoenix charge breeder, originally developed by LPSC, will be used at SPES and GANIL/SPIRAL. These two charge breeders have benefited from studies undertaken within EMILIE, which are also briefly summarized here. PMID:26932063

  15. Optimizing charge breeding techniques for ISOL facilities in Europe: Conclusions from the EMILIE project

    NASA Astrophysics Data System (ADS)

    Delahaye, P.; Galatà, A.; Angot, J.; Cam, J. F.; Traykov, E.; Ban, G.; Celona, L.; Choinski, J.; Gmaj, P.; Jardin, P.; Koivisto, H.; Kolhinen, V.; Lamy, T.; Maunoury, L.; Patti, G.; Thuillier, T.; Tarvainen, O.; Vondrasek, R.; Wenander, F.

    2016-02-01

    The present paper summarizes the results obtained from the past few years in the framework of the Enhanced Multi-Ionization of short-Lived Isotopes for Eurisol (EMILIE) project. The EMILIE project aims at improving the charge breeding techniques with both Electron Cyclotron Resonance Ion Sources (ECRIS) and Electron Beam Ion Sources (EBISs) for European Radioactive Ion Beam (RIB) facilities. Within EMILIE, an original technique for debunching the beam from EBIS charge breeders is being developed, for making an optimal use of the capabilities of CW post-accelerators of the future facilities. Such a debunching technique should eventually resolve duty cycle and time structure issues which presently complicate the data-acquisition of experiments. The results of the first tests of this technique are reported here. In comparison with charge breeding with an EBIS, the ECRIS technique had lower performance in efficiency and attainable charge state for metallic ion beams and also suffered from issues related to beam contamination. In recent years, improvements have been made which significantly reduce the differences between the two techniques, making ECRIS charge breeding more attractive especially for CW machines producing intense beams. Upgraded versions of the Phoenix charge breeder, originally developed by LPSC, will be used at SPES and GANIL/SPIRAL. These two charge breeders have benefited from studies undertaken within EMILIE, which are also briefly summarized here.

  16. Optimization of image acquisition techniques for dual-energy imaging of the chest

    SciTech Connect

    Shkumat, N. A.; Siewerdsen, J. H.; Dhanantwari, A. C.; Williams, D. B.; Richard, S.; Paul, N. S.; Yorkston, J.; Van Metter, R.

    2007-10-15

    Experimental and theoretical studies were conducted to determine optimal acquisition techniques for a prototype dual-energy (DE) chest imaging system. Technique factors investigated included the selection of added x-ray filtration, kVp pair, and the allocation of dose between low- and high-energy projections, with total dose equal to or less than that of a conventional chest radiograph. Optima were computed to maximize lung nodule detectability as characterized by the signal-difference-to-noise ratio (SDNR) in DE chest images. Optimal beam filtration was determined by cascaded systems analysis of DE image SDNR for filter selections across the periodic table (Z{sub filter}=1-92), demonstrating the importance of differential filtration between low- and high-kVp projections and suggesting optimal high-kVp filters in the range Z{sub filter}=25-50. For example, added filtration of {approx}2.1 mm Cu, {approx}1.2 mm Zr, {approx}0.7 mm Mo, and {approx}0.6 mm Ag to the high-kVp beam provided optimal (and nearly equivalent) soft-tissue SDNR. Optimal kVp pair and dose allocation were investigated using a chest phantom presenting simulated lung nodules and ribs for thin, average, and thick body habitus. Low- and high-energy techniques ranged from 60-90 kVp and 120-150 kVp, respectively, with peak soft-tissue SDNR achieved at [60/120] kVp for all patient thicknesses and all levels of imaging dose. A strong dependence on the kVp of the low-energy projection was observed. Optimal allocation of dose between low- and high-energy projections was such that {approx}30% of the total dose was delivered by the low-kVp projection, exhibiting a fairly weak dependence on kVp pair and dose. The results have guided the implementation of a prototype DE imaging system for imaging trials in early-stage lung nodule detection and diagnosis.

  17. Maintaining Optimal Surgical Conditions With Low Insufflation Pressures is Possible With Deep Neuromuscular Blockade During Laparoscopic Colorectal Surgery

    PubMed Central

    Kim, Myoung Hwa; Lee, Ki Young; Lee, Kang-Young; Min, Byung-Soh; Yoo, Young Chul

    2016-01-01

    Abstract Carbon dioxide (CO2) absorption and increased intra-abdominal pressure can adversely affect perioperative physiology and postoperative recovery. Deep muscle relaxation is known to improve the surgical conditions during laparoscopic surgery. We aimed to compare the effects of deep and moderate neuromuscular block in laparoscopic colorectal surgery, including intra-abdominal pressure. In this prospective, double-blind, parallel-group trial, 72 adult patients undergoing laparoscopic colorectal surgery were randomized using an online randomization generator to achieve either moderate (1–2 train-of-four response, n = 36) or deep (1–2 post-tetanic count, n = 36) neuromuscular block by receiving a continuous infusion of rocuronium. Adjusted intra-abdominal pressure, which was titrated by a surgeon with maintaining the operative field during pneumoperitoneum, was recorded at 5-minute intervals. Perioperative hemodynamic parameters and postoperative outcomes were assessed. Six patients from the deep and 5 from the moderate neuromuscular block group were excluded, leaving 61 for analysis. The average adjusted IAP was lower in the deep compared to the moderate neuromuscular block group (9.3 vs 12 mm Hg, P < 0.001). The postoperative pain scores (P < 0.001) and incidence of postoperative shoulder tip pain were lower, whereas gas passing time (P = 0.002) and sips of water time (P = 0.005) were shorter in the deep neuromuscular block than in the moderate neuromuscular block group. Deep neuromuscular blocking showed several benefits compared to conventional moderate neuromuscular block, including a greater intra-abdominal pressure lowering effect, whereas surgical conditions are maintained, less severe postoperative pain and faster bowel function recovery. PMID:26945393

  18. A review on optimization production and upgrading biogas through CO2 removal using various techniques.

    PubMed

    Andriani, Dian; Wresta, Arini; Atmaja, Tinton Dwi; Saepudin, Aep

    2014-02-01

    Biogas from anaerobic digestion of organic materials is a renewable energy resource that consists mainly of CH4 and CO2. Trace components that are often present in biogas are water vapor, hydrogen sulfide, siloxanes, hydrocarbons, ammonia, oxygen, carbon monoxide, and nitrogen. Considering the biogas is a clean and renewable form of energy that could well substitute the conventional source of energy (fossil fuels), the optimization of this type of energy becomes substantial. Various optimization techniques in biogas production process had been developed, including pretreatment, biotechnological approaches, co-digestion as well as the use of serial digester. For some application, the certain purity degree of biogas is needed. The presence of CO2 and other trace components in biogas could affect engine performance adversely. Reducing CO2 content will significantly upgrade the quality of biogas and enhancing the calorific value. Upgrading is generally performed in order to meet the standards for use as vehicle fuel or for injection in the natural gas grid. Different methods for biogas upgrading are used. They differ in functioning, the necessary quality conditions of the incoming gas, and the efficiency. Biogas can be purified from CO2 using pressure swing adsorption, membrane separation, physical or chemical CO2 absorption. This paper reviews the various techniques, which could be used to optimize the biogas production as well as to upgrade the biogas quality.

  19. On large-scale nonlinear programming techniques for solving optimal control problems

    SciTech Connect

    Faco, J.L.D.

    1994-12-31

    The formulation of decision problems by Optimal Control Theory allows the consideration of their dynamic structure and parameters estimation. This paper deals with techniques for choosing directions in the iterative solution of discrete-time optimal control problems. A unified formulation incorporates nonlinear performance criteria and dynamic equations, time delays, bounded state and control variables, free planning horizon and variable initial state vector. In general they are characterized by a large number of variables, mostly when arising from discretization of continuous-time optimal control or calculus of variations problems. In a GRG context the staircase structure of the jacobian matrix of the dynamic equations is exploited in the choice of basic and super basic variables and when changes of basis occur along the process. The search directions of the bound constrained nonlinear programming problem in the reduced space of the super basic variables are computed by large-scale NLP techniques. A modified Polak-Ribiere conjugate gradient method and a limited storage quasi-Newton BFGS method are analyzed and modifications to deal with the bounds on the variables are suggested based on projected gradient devices with specific linesearches. Some practical models are presented for electric generation planning and fishery management, and the application of the code GRECO - Gradient REduit pour la Commande Optimale - is discussed.

  20. Integration of ab-initio nuclear calculation with derivative free optimization technique

    SciTech Connect

    Sharda, Anurag

    2008-01-01

    Optimization techniques are finding their inroads into the field of nuclear physics calculations where the objective functions are very complex and computationally intensive. A vast space of parameters needs searching to obtain a good match between theoretical (computed) and experimental observables, such as energy levels and spectra. Manual calculation defies the scope of such complex calculation and are prone to error at the same time. This body of work attempts to formulate a design and implement it which would integrate the ab initio nuclear physics code MFDn and the VTDIRECT95 code. VTDIRECT95 is a Fortran95 suite of parallel code implementing the derivative-free optimization algorithm DIRECT. Proposed design is implemented for a serial and parallel version of the optimization technique. Experiment with the initial implementation of the design showing good matches for several single-nucleus cases are conducted. Determination and assignment of appropriate number of processors for parallel integration code is implemented to increase the efficiency and resource utilization in the case of multiple nuclei parameter search.

  1. Artificial intelligent techniques for optimizing water allocation in a reservoir watershed

    NASA Astrophysics Data System (ADS)

    Chang, Fi-John; Chang, Li-Chiu; Wang, Yu-Chung

    2014-05-01

    This study proposes a systematical water allocation scheme that integrates system analysis with artificial intelligence techniques for reservoir operation in consideration of the great uncertainty upon hydrometeorology for mitigating droughts impacts on public and irrigation sectors. The AI techniques mainly include a genetic algorithm and adaptive-network based fuzzy inference system (ANFIS). We first derive evaluation diagrams through systematic interactive evaluations on long-term hydrological data to provide a clear simulation perspective of all possible drought conditions tagged with their corresponding water shortages; then search the optimal reservoir operating histogram using genetic algorithm (GA) based on given demands and hydrological conditions that can be recognized as the optimal base of input-output training patterns for modelling; and finally build a suitable water allocation scheme through constructing an adaptive neuro-fuzzy inference system (ANFIS) model with a learning of the mechanism between designed inputs (water discount rates and hydrological conditions) and outputs (two scenarios: simulated and optimized water deficiency levels). The effectiveness of the proposed approach is tested on the operation of the Shihmen Reservoir in northern Taiwan for the first paddy crop in the study area to assess the water allocation mechanism during drought periods. We demonstrate that the proposed water allocation scheme significantly and substantially avails water managers of reliably determining a suitable discount rate on water supply for both irrigation and public sectors, and thus can reduce the drought risk and the compensation amount induced by making restrictions on agricultural use water.

  2. The axillary approach to raising the latissimus dorsi free flap for facial re-animation: a descriptive surgical technique.

    PubMed

    Leckenby, Jonathan; Butler, Daniel; Grobbelaar, Adriaan

    2015-01-01

    The latissimus dorsi flap is popular due to the versatile nature of its applications. When used as a pedicled flap it provides a robust solution when soft tissue coverage is required following breast, thoracic and head and neck surgery. Its utilization as a free flap is extensive due to the muscle's size, constant anatomy, large caliber of the pedicle and the fact it can be used for functional muscle transfers. In facial palsy it provides the surgeon with a long neurovascular pedicle that is invaluable in situations where commonly used facial vessels are not available, in congenital cases or where previous free functional muscle transfers have been attempted, or patients where a one-stage procedure is indicated and a long nerve is required to reach the contra-lateral side. Although some facial palsy surgeons use the trans-axillary approach, an operative guide of raising the flap by this method has not been provided. A clear guide of raising the flap with the patient in the supine position is described in detail and offers the benefits of reducing the risk of potential brachial plexus injury and allows two surgical teams to work synchronously to reduce operative time.

  3. Central pancreatectomy: The Dagradi Serio Iacono operation. Evolution of a surgical technique from the pioneers to the robotic approach

    PubMed Central

    Iacono, Calogero; Ruzzenente, Andrea; Bortolasi, Luca; Guglielmi, Alfredo

    2014-01-01

    Central pancreatectomy (CP) is a parenchyma-sparing surgical procedure. The aims are to clarify the history and the development of CP and to give credits to those from whom it came. Ehrhardt, in 1908, described segmental neck resection (SNR) followed, in 1910, by Finney without reconstructive part. In 1950 Honjyo described two cases of SNR combined with gastrectomy for gastric cancer infiltrating the neck of the pancreas. Guillemin and Bessot (1957) and Letton and Wilson (1959) dealt only with the reconstructive aspect of CP. Dagradi and Serio, in 1982, performed the first CP including the resective and reconstructive aspects. Subsequently Iacono has validated it with functional endocrine and exocrine tests and popularized it worldwide. In 2003, Baca and Bokan performed laparoscopic CP and, In 2004, Giulianotti et al performed a robotic assisted CP. CP is performed worldwide either by open surgery or by using minimally-invasive or robotic approaches. This confirms that the operation does not belong to whom introduced it but to everyone who carries out it; however credit must be given to those from whom it came. PMID:25400451

  4. A Survey on Optimal Signal Processing Techniques Applied to Improve the Performance of Mechanical Sensors in Automotive Applications

    PubMed Central

    Hernandez, Wilmar

    2007-01-01

    In this paper a survey on recent applications of optimal signal processing techniques to improve the performance of mechanical sensors is made. Here, a comparison between classical filters and optimal filters for automotive sensors is made, and the current state of the art of the application of robust and optimal control and signal processing techniques to the design of the intelligent (or smart) sensors that today's cars need is presented through several experimental results that show that the fusion of intelligent sensors and optimal signal processing techniques is the clear way to go. However, the switch between the traditional methods of designing automotive sensors and the new ones cannot be done overnight because there are some open research issues that have to be solved. This paper draws attention to one of the open research issues and tries to arouse researcher's interest in the fusion of intelligent sensors and optimal signal processing techniques.

  5. [The use of minimally invasive instrumental spinal surgical technique in lumbar diseases of degenerative or traumatic origin].

    PubMed

    Schwarcz, Attila; Kasó, Gábor; Büki, András; Dóczi, Tamás

    2013-03-30

    Paradigm change has recently taken place in spine surgery with the application of minimally invasive techniques. Minimally invasive techniques have several advantages over the open traditional techniques: less blood loss, preservation of spine muscle integrity, shorter hospitalization, early mobilization, reduced pain levels, lower risk of infection. The presented cases cover following lumbar pathologies: segmental spinal instability, LV-SI grade II. spondylolisthesis, degenerative spondylolisthesis, spine trauma. Unilateral or bilateral mini-open technique was employed in the degenerative cases, depending on symptoms and signes. If unilateral symptoms--pathology was identified, screws and rod were implanted percutaneously on the side contralateral to the pathology. The segmental fusion between vertebral bodies was always assured by a cage and autologous bone. The presented trauma case involved combined AO type A2 and B fractures. The anterior column was strengthened with vertebral body stents filled with bone cement, the posterior column was fixed with a percutaneously implanted screw rod system. Insertion of stents in the collapsed vertebra significantly increased the vertebral body height and also improved the stability of the spine. Minimally invasive spine surgery techniques appear more advantageous over the traditional open spine surgery that necessitates for large midline approaches. PMID:23750428

  6. Tips and tricks of the surgical technique for borderline resectable pancreatic cancer: mesenteric approach and modified distal pancreatectomy with en-bloc celiac axis resection.

    PubMed

    Hirono, Seiko; Yamaue, Hiroki

    2015-02-01

    Borderline resectable (BR) pancreatic cancer involves the portal vein and/or superior mesenteric vein (PV/SMV), major arteries including the superior mesenteric artery (SMA) or common hepatic artery (CHA), and sometimes includes the involvement of the celiac axis. We herein describe tips and tricks for a surgical technique with video assistance, which may increase the R0 rates and decrease the mortality and morbidity for BR pancreatic cancer patients. First, we describe the techniques used for the "artery-first" approach for BR pancreatic cancer with involvement of the PV/SMV and/or SMA. Next, we describe the techniques used for distal pancreatectomy with en-bloc celiac axis resection (DP-CAR) and tips for decreasing the delayed gastric emptying (DGE) rates for advanced pancreatic body cancer. The mesenteric approach, followed by the dissection of posterior tissues of the SMV and SMA, is a feasible procedure to obtain R0 rates and decrease the mortality and morbidity, and the combination of this aggressive procedure and adjuvant chemo(radiation) therapy may improve the survival of BR pancreatic cancer patients. The DP-CAR procedure may increase the R0 rates for pancreatic cancer patients with involvement within 10 mm from the root of the splenic artery, as well as the CHA or celiac axis, and preserving the left gastric artery may lead to a decrease in the DGE rates in cases where there is more than 10 mm between the tumor edge and the root of the left gastric artery. The development of safer surgical procedures is necessary to improve the survival of BR pancreatic cancer patients.

  7. Identifying Ensembles of Signal Transduction Models using Pareto Optimal Ensemble Techniques (POETs)

    PubMed Central

    Song, Sang Ok; Chakrabarti, Anirikh; Varner, Jeffrey D.

    2010-01-01

    Mathematical modeling of complex gene expression programs is an emerging tool for understanding disease mechanisms. However, identification of large models sometimes requires training using qualitative, conflicting or even contradictory data sets. One strategy to address this challenge is to estimate experimentally constrained model ensembles using multiobjective optimization. In this study, we used Pareto Optimal Ensemble Techniques (POETs) to identify a family of proof-of-concept signal transduction models. POETs integrate Simulated Annealing (SA) with Pareto optimality to identify models near the optimal tradeoff surface between competing training objectives. We modeled a prototypical-signaling network using mass action kinetics within an ordinary differential equation (ODE) framework (64-ODEs in total). The true model was used to generate synthetic immunoblots from which the POET algorithm identified the 117 unknown model parameters. POET generated an ensemble of signaling models, which collectively exhibited population-like behavior. For example, scaled gene expression levels were approximately normally distributed over the ensemble following the addition of extracellular ligand. Also, the ensemble recovered robust and fragile features of the true model, despite significant parameter uncertainty. Taken together, these results suggest that experimentally constrained model ensembles could capture qualitatively important network features without exact parameter information. PMID:20665647

  8. Ensembles of signal transduction models using Pareto Optimal Ensemble Techniques (POETs).

    PubMed

    Song, Sang Ok; Chakrabarti, Anirikh; Varner, Jeffrey D

    2010-07-01

    Mathematical modeling of complex gene expression programs is an emerging tool for understanding disease mechanisms. However, identification of large models sometimes requires training using qualitative, conflicting or even contradictory data sets. One strategy to address this challenge is to estimate experimentally constrained model ensembles using multiobjective optimization. In this study, we used Pareto Optimal Ensemble Techniques (POETs) to identify a family of proof-of-concept signal transduction models. POETs integrate Simulated Annealing (SA) with Pareto optimality to identify models near the optimal tradeoff surface between competing training objectives. We modeled a prototypical-signaling network using mass-action kinetics within an ordinary differential equation (ODE) framework (64 ODEs in total). The true model was used to generate synthetic immunoblots from which the POET algorithm identified the 117 unknown model parameters. POET generated an ensemble of signaling models, which collectively exhibited population-like behavior. For example, scaled gene expression levels were approximately normally distributed over the ensemble following the addition of extracellular ligand. Also, the ensemble recovered robust and fragile features of the true model, despite significant parameter uncertainty. Taken together, these results suggest that experimentally constrained model ensembles could capture qualitatively important network features without exact parameter information.

  9. Total Pancreatectomy and Islet Auto-Transplantation in Children for Chronic Pancreatitis. Indication, Surgical Techniques, Post Operative Management and Long-Term Outcomes

    PubMed Central

    Chinnakotla, Srinath; Bellin, Melena D.; Schwarzenberg, Sarah J.; Radosevich, David M.; Cook, Marie; Dunn, Ty B.; Beilman, Gregory J.; Freeman, Martin L.; Balamurugan, A.N.; Wilhelm, Josh; Bland, Barbara; Jimenez-Vega, Jose M; Hering, Bernhard J.; Vickers, Selwyn M.; Pruett, Timothy L.; Sutherland, David E.R.

    2014-01-01

    Objective Describe the surgical technique, complications and long term outcomes of total pancreatectomy and islet auto transplantation (TP-IAT) in a large series of pediatric patients. Summary Background Data Surgical management of childhood pancreatitis is not clear; partial resection or drainage procedures often provide transient pain relief, but long term recurrence is common due to the diffuse involvement of the pancreas. Total pancreatectomy (TP) removes the source of the pain, while islet auto transplantation (IAT) potentially can prevent or minimize TP-related diabetes. Methods Retrospective review of 75 children undergoing TP-IAT for chronic pancreatitis who had failed medical, endoscopic or surgical treatment between 1989–2012. Results Pancreatitis pain and the severity of pain statistically improved in 90% of patients after TP-IAT (p =<0.001). The relief from narcotics was sustained. Of the 75 patients undergoing TP-IAT, 31 (41.3%) achieved insulin independence. Younger age (p=0.032), lack of prior Puestow (p=0.018), lower body surface area (p=0.048), IEQ per Kg Body Weight (p=0.001) and total IEQ (100,000) (0.004) were associated with insulin independence. By multivariate analysis, 3 factors were associated with insulin independence after TP-IAT:(1) male gender, (2) lower body surface area and the (3) higher total IEQ per kilogram body weight. Total IEQ (100,000) was the single factor most strongly associated with insulin independence (OR = 2.62; p value < 0.001). Conclusions TP-IAT provides sustained pain relief and improved quality of life. The β cell function is dependent on islet yield. TP-IAT is an effective therapy for children with painful pancreatitis that fail medical and or endoscopic management PMID:24509206

  10. Optimized scheduling technique of null subcarriers for peak power control in 3GPP LTE downlink.

    PubMed

    Cho, Soobum; Park, Sang Kyu

    2014-01-01

    Orthogonal frequency division multiple access (OFDMA) is a key multiple access technique for the long term evolution (LTE) downlink. However, high peak-to-average power ratio (PAPR) can cause the degradation of power efficiency. The well-known PAPR reduction technique, dummy sequence insertion (DSI), can be a realistic solution because of its structural simplicity. However, the large usage of subcarriers for the dummy sequences may decrease the transmitted data rate in the DSI scheme. In this paper, a novel DSI scheme is applied to the LTE system. Firstly, we obtain the null subcarriers in single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems, respectively; then, optimized dummy sequences are inserted into the obtained null subcarrier. Simulation results show that Walsh-Hadamard transform (WHT) sequence is the best for the dummy sequence and the ratio of 16 to 20 for the WHT and randomly generated sequences has the maximum PAPR reduction performance. The number of near optimal iteration is derived to prevent exhausted iterations. It is also shown that there is no bit error rate (BER) degradation with the proposed technique in LTE downlink system.

  11. Optimized Scheduling Technique of Null Subcarriers for Peak Power Control in 3GPP LTE Downlink

    PubMed Central

    Park, Sang Kyu

    2014-01-01

    Orthogonal frequency division multiple access (OFDMA) is a key multiple access technique for the long term evolution (LTE) downlink. However, high peak-to-average power ratio (PAPR) can cause the degradation of power efficiency. The well-known PAPR reduction technique, dummy sequence insertion (DSI), can be a realistic solution because of its structural simplicity. However, the large usage of subcarriers for the dummy sequences may decrease the transmitted data rate in the DSI scheme. In this paper, a novel DSI scheme is applied to the LTE system. Firstly, we obtain the null subcarriers in single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems, respectively; then, optimized dummy sequences are inserted into the obtained null subcarrier. Simulation results show that Walsh-Hadamard transform (WHT) sequence is the best for the dummy sequence and the ratio of 16 to 20 for the WHT and randomly generated sequences has the maximum PAPR reduction performance. The number of near optimal iteration is derived to prevent exhausted iterations. It is also shown that there is no bit error rate (BER) degradation with the proposed technique in LTE downlink system. PMID:24883376

  12. [Optimization on alcohol precipitation techniques of Liuwei Dihuang decoction by response surface methodology].

    PubMed

    Yan, Ming; Wei, Ying-chun; Li, Xue-feng; Meng, Jin; Wu, Yun; Xiao, Wei

    2015-10-01

    The theoretical basis of the alcohol precipitation process control was provided, the alcohol precipitation was optimized and the relationship equation was got. The monod glycoside, loganin and paeoniflorin were used as the evaluation indexes to determine the impact factors of alcohol precipitation techniques of Liuwei Dihuang decoction by the Plackett-Burman experimental design and the levels of non-significant factors were identified. Then, Box-Behnken response surface methodology was used to research and discuss the critical process parameters influence the effect of alcohol precipitation and draw interaction between key process parameters and the correlation equation with index components. Through the establishment and solving the quadratic regression model of composite score, the optimum preparation conditions of alcohol precipitation techniques of liuwei were as follows: stirring speed was 580 r x min(-1), standing time was 17 hours, alcohol concentration was 34%, the density of Liuwei Dihuang decoction was 1.13. The response surface methodology for optimized alcohol precipitation techniques of Liuwei Dihuang decoction is. reasonable and feasible.

  13. Human motion planning based on recursive dynamics and optimal control techniques

    NASA Technical Reports Server (NTRS)

    Lo, Janzen; Huang, Gang; Metaxas, Dimitris

    2002-01-01

    This paper presents an efficient optimal control and recursive dynamics-based computer animation system for simulating and controlling the motion of articulated figures. A quasi-Newton nonlinear programming technique (super-linear convergence) is implemented to solve minimum torque-based human motion-planning problems. The explicit analytical gradients needed in the dynamics are derived using a matrix exponential formulation and Lie algebra. Cubic spline functions are used to make the search space for an optimal solution finite. Based on our formulations, our method is well conditioned and robust, in addition to being computationally efficient. To better illustrate the efficiency of our method, we present results of natural looking and physically correct human motions for a variety of human motion tasks involving open and closed loop kinematic chains.

  14. Optimization techniques applied to passive measures for in-orbit spacecraft survivability

    NASA Technical Reports Server (NTRS)

    Mog, Robert A.; Price, D. Marvin

    1991-01-01

    Spacecraft designers have always been concerned about the effects of meteoroid impacts on mission safety. The engineering solution to this problem has generally been to erect a bumper or shield placed outboard from the spacecraft wall to disrupt/deflect the incoming projectiles. Spacecraft designers have a number of tools at their disposal to aid in the design process. These include hypervelocity impact testing, analytic impact predictors, and hydrodynamic codes. Analytic impact predictors generally provide the best quick-look estimate of design tradeoffs. The most complete way to determine the characteristics of an analytic impact predictor is through optimization of the protective structures design problem formulated with the predictor of interest. Space Station Freedom protective structures design insight is provided through the coupling of design/material requirements, hypervelocity impact phenomenology, meteoroid and space debris environment sensitivities, optimization techniques and operations research strategies, and mission scenarios. Major results are presented.

  15. Parameterized CAD techniques implementation for the fatigue behaviour optimization of a service chamber

    NASA Astrophysics Data System (ADS)

    Sánchez, H. T.; Estrems, M.; Franco, P.; Faura, F.

    2009-11-01

    In recent years, the market of heat exchangers is increasingly demanding new products in short cycle time, which means that both the design and manufacturing stages must be extremely reduced. The design stage can be reduced by means of CAD-based parametric design techniques. The methodology presented in this proceeding is based on the optimized control of geometric parameters of a service chamber of a heat exchanger by means of the Application Programming Interface (API) provided by the Solidworks CAD package. Using this implementation, a set of different design configurations of the service chamber made of stainless steel AISI 316 are studied by means of the FE method. As a result of this study, a set of knowledge rules based on the fatigue behaviour are constructed and integrated into the design optimization process.

  16. Development of a parameter optimization technique for the design of automatic control systems

    NASA Technical Reports Server (NTRS)

    Whitaker, P. H.

    1977-01-01

    Parameter optimization techniques for the design of linear automatic control systems that are applicable to both continuous and digital systems are described. The model performance index is used as the optimization criterion because of the physical insight that can be attached to it. The design emphasis is to start with the simplest system configuration that experience indicates would be practical. Design parameters are specified, and a digital computer program is used to select that set of parameter values which minimizes the performance index. The resulting design is examined, and complexity, through the use of more complex information processing or more feedback paths, is added only if performance fails to meet operational specifications. System performance specifications are assumed to be such that the desired step function time response of the system can be inferred.

  17. a High-Level Technique for Estimation and Optimization of Leakage Power for Full Adder

    NASA Astrophysics Data System (ADS)

    Shrivas, Jayram; Akashe, Shyam; Tiwari, Nitesh

    2013-04-01

    Optimization of power is a very important issue in low-voltage and low-power application. In this paper, we have proposed power gating technique to reduce leakage current and leakage power of one-bit full adder. In this power gating technique, we use two sleep transistors i.e., PMOS and NMOS. PMOS sleep transistor is inserted between power supply and pull up network. And NMOS sleep transistor is inserted between pull down network and ground terminal. These sleep transistors (PMOS and NMOS) are turned on when the circuit is working in active mode. And sleep transistors (PMOS and NMOS) are turned off when circuit is working in standby mode. We have simulated one-bit full adder and compared with the power gating technique using cadence virtuoso tool in 45 nm technology at 0.7 V at 27°C. By applying this technique, we have reduced leakage current from 2.935 pA to 1.905 pA and leakage power from 25.04μw to 9.233μw. By using this technique, we have reduced leakage power up to 63.12%.

  18. Recent advances in the surgical management of rhinosinusitis

    PubMed Central

    Jaksha, Alexandria F.; Weitzel, Erik K.; Laury, Adrienne M.

    2016-01-01

    Rhinosinusitis affects a significant portion of the US population, and its management imposes a substantial burden on the healthcare system. The treatment of chronic rhinosinusitis includes initial medical management prior to consideration of surgical intervention. However, if surgery does become necessary, several factors must be considered in order to optimize outcomes. This review evaluates surgical patient selection, perioperative medical management, and the extent of operative intervention, with the goal of improving surgical results, decreasing the need for revision surgery, and enhancing the patient’s quality of life. Specific variations in patient genotypes and phenotypes will be further explored with regard to their implications on surgical outcomes. Additionally, the evidence behind pre- and post-operative antibiotic and steroid use will be evaluated. Finally, we will review evolving surgical tools and techniques that are currently being utilized for the treatment of specific subsets of rhinosinusitis. PMID:27746900

  19. Comparison of Surgical Outcomes Between Short-Segment Open and Percutaneous Pedicle Screw Fixation Techniques for Thoracolumbar Fractures.

    PubMed

    Fu, Zhiguo; Zhang, Xi; Shi, Yaohua; Dong, Qirong

    2016-01-01

    BACKGROUND This study aimed to compare the surgical outcomes between open pedicle screw fixation (OPSF) and percutaneous pedicle screw fixation (PPSF) for the treatment of thoracolumbar fractures, which has received scant research attention to date. MATERIAL AND METHODS Eight-four patients with acute and subacute thoracolumbar fractures who were treated with SSPSF from January 2013 to June 2014 at the Changzhou Hospital of Traditional Chinese Medicine (Changzhou, China) were retrospectively reviewed. The patients were divided into 4 groups: the OPSF with 4 basic screws (OPSF-4) group, the OPSF with 4 basic and 2 additional screws (OPSF-6) group, the PPSF with 4 basic screws (PPSF-4) group, and the PPSF with 4 basic and 2 additional screws (PPSF-6) group. The intraoperative, immediate postoperative, and over 1-year follow-up outcomes were evaluated and compared among these groups. RESULTS Blood loss in the PPSF-4 group and the PPSF-6 group was significantly less than in the OPSF-4 group and the OPSF-6 group (P<0.05). The OPSF-6 group exhibited significantly higher immediate postoperative correction percentage of anterior column height of fractured vertebra than the other 3 groups (P<0.05), and higher correction of sagittal regional Cobb angle and kyphotic angle of injured vertebra than in the PPSF-4 and -6 groups (P<0.05). In addition, there was no significant difference in the correction loss of percentage of anterior column height, and loss of sagittal Cobb angle and kyphotic angle of fractured vertebrae at final follow-up among the 4 groups (P>0.05). CONCLUSIONS OPSF with 6 screws had an advantage in the correction of injured vertebral height and kyphosis, and PPSF reduced the intraoperative blood loss of patients. PMID:27602557

  20. Comparison of Surgical Outcomes Between Short-Segment Open and Percutaneous Pedicle Screw Fixation Techniques for Thoracolumbar Fractures

    PubMed Central

    Fu, Zhiguo; Zhang, Xi; Shi, Yaohua; Dong, Qirong

    2016-01-01

    Background This study aimed to compare the surgical outcomes between open pedicle screw fixation (OPSF) and percutaneous pedicle screw fixation (PPSF) for the treatment of thoracolumbar fractures, which has received scant research attention to date. Material/Methods Eight-four patients with acute and subacute thoracolumbar fractures who were treated with SSPSF from January 2013 to June 2014 at the Changzhou Hospital of Traditional Chinese Medicine (Changzhou, China) were retrospectively reviewed. The patients were divided into 4 groups: the OPSF with 4 basic screws (OPSF-4) group, the OPSF with 4 basic and 2 additional screws (OPSF-6) group, the PPSF with 4 basic screws (PPSF-4) group, and the PPSF with 4 basic and 2 additional screws (PPSF-6) group. The intraoperative, immediate postoperative, and over 1-year follow-up outcomes were evaluated and compared among these groups. Results Blood loss in the PPSF-4 group and the PPSF-6 group was significantly less than in the OPSF-4 group and the OPSF-6 group (P<0.05). The OPSF-6 group exhibited significantly higher immediate postoperative correction percentage of anterior column height of fractured vertebra than the other 3 groups (P<0.05), and higher correction of sagittal regional Cobb angle and kyphotic angle of injured vertebra than in the PPSF-4 and -6 groups (P<0.05). In addition, there was no significant difference in the correction loss of percentage of anterior column height, and loss of sagittal Cobb angle and kyphotic angle of fractured vertebrae at final follow-up among the 4 groups (P>0.05). Conclusions OPSF with 6 screws had an advantage in the correction of injured vertebral height and kyphosis, and PPSF reduced the intraoperative blood loss of patients. PMID:27602557

  1. A technique for optimal temperature estimation for modeling sunrise/sunset thermal snap disturbance torque

    NASA Technical Reports Server (NTRS)

    Zimbelman, D. F.; Dennehy, C. J.; Welch, R. V.; Born, G. H.

    1990-01-01

    A predictive temperature estimation technique which can be used to drive a model of the Sunrise/Sunset thermal 'snap' disturbance torque experienced by low Earth orbiting spacecraft is described. The twice per orbit impulsive disturbance torque is attributed to vehicle passage in and out of the Earth's shadow cone (umbra), during which large flexible appendages undergo rapidly changing thermal conditions. Flexible members, in particular solar arrays, experience rapid cooling during umbra entrance (Sunset) and rapid heating during exit (Sunrise). The thermal 'snap' phenomena has been observed during normal on-orbit operations of both the LANDSAT-4 satellite and the Communications Technology Satellite (CTS). Thermal 'snap' has also been predicted to be a dominant source of error for the TOPEX satellite. The fundamental equations used to model the Sunrise/Sunset thermal 'snap' disturbance torque for a typical solar array like structure will be described. For this derivation the array is assumed to be a thin, cantilevered beam. The time varying thermal gradient is shown to be the driving force behind predicting the thermal 'snap' disturbance torque and therefore motivates the need for accurate estimates of temperature. The development of a technique to optimally estimate appendage surface temperature is highlighted. The objective analysis method used is structured on the Gauss-Markov Theorem and provides an optimal temperature estimate at a prescribed location given data from a distributed thermal sensor network. The optimally estimated surface temperatures could then be used to compute the thermal gradient across the body. The estimation technique is demonstrated using a typical satellite solar array.

  2. Surgical smoke.

    PubMed

    Fan, Joe King-Man; Chan, Fion Siu-Yin; Chu, Kent-Man

    2009-10-01

    Surgical smoke is the gaseous by-product formed during surgical procedures. Most surgeons, operating theatre staff and administrators are unaware of its potential health risks. Surgical smoke is produced by various surgical instruments including those used in electrocautery, lasers, ultrasonic scalpels, high speed drills, burrs and saws. The potential risks include carbon monoxide toxicity to the patient undergoing a laparoscopic operation, pulmonary fibrosis induced by non-viable particles, and transmission of infectious diseases like human papilloma virus. Cytotoxicity and mutagenicity are other concerns. Minimisation of the production of surgical smoke and modification of any evacuation systems are possible solutions. In general, a surgical mask can provide more than 90% protection to exposure to surgical smoke; however, in most circumstances it cannot provide air-tight protection to the user. An at least N95 grade or equivalent respirator offers the best protection against surgical smoke, but whether such protection is necessary is currently unknown. PMID:19892630

  3. Optimization techniques applied to passive measures for in-orbit spacecraft survivability

    NASA Technical Reports Server (NTRS)

    Mog, Robert A.; Helba, Michael J.; Hill, Janeil B.

    1992-01-01

    The purpose of this research is to provide Space Station Freedom protective structures design insight through the coupling of design/material requirements, hypervelocity impact phenomenology, meteoroid and space debris environment sensitivities, optimization techniques and operations research strategies, and mission scenarios. The goals of the research are: (1) to develop a Monte Carlo simulation tool which will provide top level insight for Space Station protective structures designers; (2) to develop advanced shielding concepts relevant to Space Station Freedom using unique multiple bumper approaches; and (3) to investigate projectile shape effects on protective structures design.

  4. New efficient optimizing techniques for Kalman filters and numerical weather prediction models

    NASA Astrophysics Data System (ADS)

    Famelis, Ioannis; Galanis, George; Liakatas, Aristotelis

    2016-06-01

    The need for accurate local environmental predictions and simulations beyond the classical meteorological forecasts are increasing the last years due to the great number of applications that are directly or not affected: renewable energy resource assessment, natural hazards early warning systems, global warming and questions on the climate change can be listed among them. Within this framework the utilization of numerical weather and wave prediction systems in conjunction with advanced statistical techniques that support the elimination of the model bias and the reduction of the error variability may successfully address the above issues. In the present work, new optimization methods are studied and tested in selected areas of Greece where the use of renewable energy sources is of critical. The added value of the proposed work is due to the solid mathematical background adopted making use of Information Geometry and Statistical techniques, new versions of Kalman filters and state of the art numerical analysis tools.

  5. A model based technique for the design of flight directors. [optimal control models

    NASA Technical Reports Server (NTRS)

    Levison, W. H.

    1973-01-01

    A new technique for designing flight directors is discussed. This technique uses the optimal-control pilot/vehicle model to determine the appropriate control strategy. The dynamics of this control strategy are then incorporated into the director control laws, thereby enabling the pilot to operate at a significantly lower workload. A preliminary design of a control director for maintaining a STOL vehicle on the approach path in the presence of random air turbulence is evaluated. By selecting model parameters in terms of allowable path deviations and pilot workload levels, a set of director laws is achieved which allows improved system performance at reduced workload levels. The pilot acts essentially as a proportional controller with regard to the director signals, and control motions are compatible with those appropriate to status-only displays.

  6. Design and optimization of stepped austempered ductile iron using characterization techniques

    SciTech Connect

    Hernández-Rivera, J.L.; Garay-Reyes, C.G.; Campos-Cambranis, R.E.; Cruz-Rivera, J.J.

    2013-09-15

    Conventional characterization techniques such as dilatometry, X-ray diffraction and metallography were used to select and optimize temperatures and times for conventional and stepped austempering. Austenitization and conventional austempering time was selected when the dilatometry graphs showed a constant expansion value. A special heat color-etching technique was applied to distinguish between the untransformed austenite and high carbon stabilized austenite which had formed during the treatments. Finally, it was found that carbide precipitation was absent during the stepped austempering in contrast to conventional austempering, on which carbide evidence was found. - Highlights: • Dilatometry helped to establish austenitization and austempering parameters. • Untransformed austenite was present even for longer processing times. • Ausferrite formed during stepped austempering caused important reinforcement effect. • Carbide precipitation was absent during stepped treatment.

  7. Development of a novel method for surgical implant design optimization through noninvasive assessment of local bone properties.

    PubMed

    Schiuma, D; Brianza, S; Tami, A E

    2011-03-01

    A method was developed to improve the design of locking implants by finding the optimal paths for the anchoring elements, based on a high resolution pQCT assessment of local bone mineral density (BMD) distribution and bone micro-architecture (BMA). The method consists of three steps: (1) partial fixation of the implant to the bone and creation of a reference system, (2) implant removal and pQCT scan of the bone, and (3) determination of BMD and BMA of all implant-anchoring locations along the actual and alternative directions. Using a PHILOS plate, the method uncertainty was tested on an artificial humerus bone model. A cadaveric humerus was used to quantify how the uncertainty of the method affects the assessment of bone parameters. BMD and BMA were determined along four possible alternative screw paths as possible criteria for implant optimization. The method is biased by a 0.87 ± 0.12 mm systematic uncertainty and by a 0.44 ± 0.09 mm random uncertainty in locating the virtual screw position. This study shows that this method can be used to find alternative directions for the anchoring elements, which may possess better bone properties. This modification will thus produce an optimized implant design.

  8. Comparison between three mini-sling surgical procedures and the traditional transobturator vaginal tape technique for female stress urinary incontinence

    PubMed Central

    LEANZA, V.; INTAGLIATA, E.; LEANZA, A.; FERLA, F.; LEANZA, G.; VECCHIO, R.

    2014-01-01

    Objectives To compare mini-sling and traditional tension-free operations for female stress urinary incontinence. Study design A systematic review of articles in the Literature published between 2002 and 2012, was conducted. A Pubmed search was performed. Primary outcomes were subjective and objective cure rates at 12 months comparing the three single-incision mini-slings techniques (TVT-Secur, MiniArc and Monarc systems) with the standard mid-urethral sling procedure TOT (Transobturator Vaginal Tape). Secondary outcomes included peri-operative (vaginal and/or bladder perforation, urine retention, urinary tract infection, bleeding, pain) and post-operative (mesh exposure, de novo urgency, and dyspareunia) complications. Results In term of objective cure rate at 12 month after surgery, it is evident that TOT at first, and MiniArc are the most effective procedures. The incidence of post-operative urgency and UTI was lower in TOT technique, while vaginal perforation was described in equal frequency both in TOT and in MiniArc procedures. The advantages of the three above described mini-invasive techniques seem to consist into lower cases of urinary retention, pain and bleeding. Furthermore, bladder perforation and bleeding are not described in the Literature for TVT-Secur and Monarc systems. Conclusions Some single-incision slings look promising and as effective as conventional sub-urethral slings at short term evaluation. However, at this moment a clear statement in favor of the widespread use of single-incision slings cannot be made. More studies must define the efficacy of these techniques. PMID:24841685

  9. Macroscopic optical imaging technique for wide-field estimation of fluorescence depth in optically turbid media for application in brain tumor surgical guidance

    PubMed Central

    Kolste, Kolbein K.; Kanick, Stephen C.; Valdés, Pablo A.; Jermyn, Michael; Wilson, Brian C.; Roberts, David W.; Paulsen, Keith D.; Leblond, Frederic

    2015-01-01

    Abstract. A diffuse imaging method is presented that enables wide-field estimation of the depth of fluorescent molecular markers in turbid media by quantifying the deformation of the detected fluorescence spectra due to the wavelength-dependent light attenuation by overlying tissue. This is achieved by measuring the ratio of the fluorescence at two wavelengths in combination with normalization techniques based on diffuse reflectance measurements to evaluate tissue attenuation variations for different depths. It is demonstrated that fluorescence topography can be achieved up to a 5 mm depth using a near-infrared dye with millimeter depth accuracy in turbid media having optical properties representative of normal brain tissue. Wide-field depth estimates are made using optical technology integrated onto a commercial surgical microscope, making this approach feasible for real-world applications. PMID:25652704

  10. [After-cataract following intraocular lens implantation. Part I. Genesis and prevention by optimizing conventional lens implants and surgical techniques].

    PubMed

    Menapace, R

    2007-03-01

    After-cataract is the most common complication in cataract surgery. Implementing a sharp posterior optic edge has, together with improved cortical aspiration, drastically reduced its rate. The impact of optic design and material has been systematically studied in detail in Vienna in a series of prospectively randomized intra-individual comparison studies using objective evaluation methods. Circular rhexis-optic overlap is essential for the durability of the posterior sharp optic edge barrier effect. Using haptics with a capsular bag design and a slim junction to the optic enhanced it further. The use of fibrosis-inducing optic materials has been shown to prolong the barrier effect, which was decreased after anterior capsule polishing. Although the incidence of clinically significant after-cataract has been significantly reduced by these conventional measures, it still cannot be completely avoided.

  11. [Surgical technique of displacement and retraction of the heart with a pigtail shaped hook and Tentacles Heart Positioner].

    PubMed

    Shimamura, Yoshiei; Mochizuki, Y; Yamada, Y; Eda, K; Shibasaki, I; Inoue, Y; Miyoshi, S

    2007-07-01

    We describe a novel heart retracting system with Tentacles Heart Positioner (Sumitomo Bakelite, Tokyo) during off-pump coronary artery bypass grafting (OPCAB). The heart retracting system is composed of a pigtail shaped hook attached to a flexible Universal Stabilizer Arm (Estech, Minneapolis). After Tentacles suction device is applied on the surface of the heart, the retracting system is fixed on the sternal retracter so that the hook can hang and support the retracting tubes of the sucker. By regulating the shape of the Universal Stabilizer Arm and the position of the hook, the retracting system can lift the heart sufficiently and maintain the optimal position of the heart during OPCAB procedure. Together with Tentacles Heart Positioner, the heart retracting system provides excellent exposure of target coronary arteries with minimal effect on hemodynamics.

  12. Brachymetatarsia. A new surgical approach.

    PubMed

    Martin, D E; Kalish, S R

    1991-01-01

    Although most practitioners are familiar with brachymetatarsia, it is a relatively uncommon clinical entity presenting for surgical correction. Traditional methods of surgical correction have been successful for the most part; however, a number of potentially devastating complications exist with these procedures. The authors present a review of the deformity, including the historical surgical techniques, and introduce a new surgical approach that minimizes the risk of complication. PMID:1993972

  13. Use of a microdebrider for corporeal excavation and penile prosthesis implantation in men with severely fibrosed corpora cavernosa: a new minimal invasive surgical technique

    PubMed Central

    Bozkurt, İbrahim Halil; Yonguç, Tarık; Aydoğdu, Özgü; Değirmenci, Tansu; Arslan, Murat; Minareci, Süleyman

    2015-01-01

    Objective To propose a new minimal invasive surgical technique using a microdebrider (shaver) to excavate the fibrosed corpora cavernosa for penile prosthesis implantation in patients with severe fibrosis. Material and methods Two patients with severe corporeal fibrosis were implanted with a penile prosthesis using this technique. In the first patient, fibrosis was due to neglected idiopathic ischemic priapism and the second patient had his prosthesis extruded because of erosion in another center. Both patients were counseled about the procedure and the possible complications related to the experimental nature of the technique. A written informed consent was obtained from both patients. Excavation of the corpora was performed using microdebrider in both patients. Results Both operations were performed successfully without any intraoperative complications, including urethral injury or perforation of the tunica. The mean operation time was 57 min. The postoperative period was uneventful without any infection, migration, erosion, or mechanical failure. The penile length was increased nearly 2 cm in both patients, and the penile girth was increased around 30% in the patient who underwent inflatable penile prosthesis implantation. Conclusion The microdebrider potentially provides an important advance in patients with severe corporeal fibrosis to excavate the fibrosed corpora cavernosa for penile prosthesis implantation. The main advantages include fast, safe, and effective excavation of fibrous corpora cavernosa adequate for a satisfactory penile prosthesis implantation. PMID:26516594

  14. 18F-FDG PET-CT after Neoadjuvant Chemoradiotherapy in Esophageal Cancer Patients to Optimize Surgical Decision Making

    PubMed Central

    Anderegg, Maarten C. J.; de Groof, Elisabeth J.; Gisbertz, Suzanne S.; Bennink, Roel J.; Lagarde, Sjoerd M.; Klinkenbijl, Jean H. G.; Dijkgraaf, Marcel G. W.; Bergman, Jacques J. G. H. M.; Hulshof, Maarten C. C. M.; van Laarhoven, Hanneke W. M.; van Berge Henegouwen, Mark I.

    2015-01-01

    Background Prognosis of esophageal cancer patients can be significantly improved by neoadjuvant chemoradiotherapy (nCRT). Given the aggressive nature of esophageal tumors, it is conceivable that in a significant portion of patients treated with nCRT, dissemination already becomes manifest during the period of nCRT. The aim of this retrospective study was to determine the value and diagnostic accuracy of PET-CT after neoadjuvant chemoradiotherapy to identify patients with metastases preoperatively in order to prevent non-curative surgery. Methods From January 2011 until February 2013 esophageal cancer patients deemed eligible for a curative approach with nCRT and surgical resection underwent a PET-CT after completion of nCRT. If abnormalities on PET-CT were suspected metastases, histological proof was acquired. A clinical decision model was designed to assess the cost-effectiveness of this diagnostic strategy. Results 156 patients underwent a PET-CT after nCRT. In 31 patients (19.9%) PET-CT showed abnormalities suspicious for dissemination, resulting in 17 cases of proven metastases (10.9%). Of the patients without proven metastases 133 patients were operated. In 6 of these 133 cases distant metastases were detected intraoperatively, corresponding to 4.5% false-negative results. The standard introduction of a post-neoadjuvant therapy PET-CT led to a reduction of overall health care costs per patient compared to a scenario without restaging with PET-CT ($34,088 vs. $36,490). Conclusion In 10.9% of esophageal cancer patients distant metastases were detected by standard PET-CT after neoadjuvant chemoradiotherapy. To avoid non-curative resections we advocate post-neoadjuvant therapy PET-CT as a cost-effective step in the standard work-up of candidates for surgery. PMID:26529313

  15. Obtaining the optimal fuel conserving investment mix: a linear programming hedonic technique approach

    SciTech Connect

    Dinan, T.M.

    1984-01-01

    The objectives of this study were to: (1) determine how energy efficiency affects the resale value of homes; (2) use this information concerning the implicit price of energy efficiency to estimate the resale value of fuel saving investments; and (3) incorporate these resale values into the investment decision process and determine the efficient investment mix for a household planning to own a given home for three alternative time periods. Two models were used to accomplish these objectives. A hedonic price model was used to determine the impact of energy efficiency on housing prices. The hedonic technique is a method used to attach implicit prices to characteristics that are not themselves bought and sold in markets, but are components of market goods. The hedonic model in this study provided an estimate of the implicit price paid for an increase in energy efficiency in homes on the Des-Moines housing market. In order to determine how the length of time the home is to be owned affects the optimal investment mix, a linear programming model was used to determine the cost minimizing investment mix for a baseline house under the assumption that it would be owned for 6, 20, and 50 years, alternatively. The results of the hedonic technique revealed that a premium is paid for energy efficient homes in Des Moines. The results of the linear programming model reveal that the optimal fuel saving investment mix for a home is sensitive to the time the home is to be owned.

  16. Applying Reflective Middleware Techniques to Optimize a QoS-enabled CORBA Component Model Implementation

    NASA Technical Reports Server (NTRS)

    Wang, Nanbor; Parameswaran, Kirthika; Kircher, Michael; Schmidt, Douglas

    2003-01-01

    Although existing CORBA specifications, such as Real-time CORBA and CORBA Messaging, address many end-to-end quality-of service (QoS) properties, they do not define strategies for configuring these properties into applications flexibly, transparently, and adaptively. Therefore, application developers must make these configuration decisions manually and explicitly, which is tedious, error-prone, and open sub-optimal. Although the recently adopted CORBA Component Model (CCM) does define a standard configuration framework for packaging and deploying software components, conventional CCM implementations focus on functionality rather than adaptive quality-of-service, which makes them unsuitable for next-generation applications with demanding QoS requirements. This paper presents three contributions to the study of middleware for QoS-enabled component-based applications. It outlines rejective middleware techniques designed to adaptively (1) select optimal communication mechanisms, (2) manage QoS properties of CORBA components in their contain- ers, and (3) (re)con$gure selected component executors dynamically. Based on our ongoing research on CORBA and the CCM, we believe the application of rejective techniques to component middleware will provide a dynamically adaptive and (re)configurable framework for COTS software that is well-suited for the QoS demands of next-generation applications.

  17. Applying Reflective Middleware Techniques to Optimize a QoS-enabled CORBA Component Model Implementation

    NASA Technical Reports Server (NTRS)

    Wang, Nanbor; Kircher, Michael; Schmidt, Douglas C.

    2000-01-01

    Although existing CORBA specifications, such as Real-time CORBA and CORBA Messaging, address many end-to-end quality-of-service (QoS) properties, they do not define strategies for configuring these properties into applications flexibly, transparently, and adaptively. Therefore, application developers must make these configuration decisions manually and explicitly, which is tedious, error-prone, and often sub-optimal. Although the recently adopted CORBA Component Model (CCM) does define a standard configuration frame-work for packaging and deploying software components, conventional CCM implementations focus on functionality rather than adaptive quality-of service, which makes them unsuitable for next-generation applications with demanding QoS requirements. This paper presents three contributions to the study of middleware for QoS-enabled component-based applications. It outlines reflective middleware techniques designed to adaptively: (1) select optimal communication mechanisms, (2) man- age QoS properties of CORBA components in their containers, and (3) (re)configure selected component executors dynamically. Based on our ongoing research on CORBA and the CCM, we believe the application of reflective techniques to component middleware will provide a dynamically adaptive and (re)configurable framework for COTS software that is well-suited for the QoS demands of next-generation applications.

  18. Optimization and enhancement of soil bioremediation by composting using the experimental design technique.

    PubMed

    Sayara, Tahseen; Sarrà, Montserrat; Sánchez, Antoni

    2010-06-01

    The objective of this study was the application of the experimental design technique to optimize the conditions for the bioremediation of contaminated soil by means of composting. A low-cost material such as compost from the Organic Fraction of Municipal Solid Waste as amendment and pyrene as model pollutant were used. The effect of three factors was considered: pollutant concentration (0.1-2 g/kg), soil:compost mixing ratio (1:0.5-1:2 w/w) and compost stability measured as respiration index (0.78, 2.69 and 4.52 mg O2 g(-1) Organic Matter h(-1)). Stable compost permitted to achieve an almost complete degradation of pyrene in a short time (10 days). Results indicated that compost stability is a key parameter to optimize PAHs biodegradation. A factor analysis indicated that the optimal conditions for bioremediation after 10, 20 and 30 days of process were (1.4, 0.78, 1:1.4), (1.4, 2.18. 1:1.3) and (1.3, 2.18, 1:1.3) for concentration (g/kg), compost stability (mg O2 g(-1) Organic Matter h(-1)) and soil:compost mixing ratio, respectively.

  19. A comparison of two global optimization algorithms with sequential niche technique for structural model updating

    NASA Astrophysics Data System (ADS)

    Shabbir, Faisal; Omenzetter, Piotr

    2014-04-01

    Much effort is devoted nowadays to derive accurate finite element (FE) models to be used for structural health monitoring, damage detection and assessment. However, formation of a FE model representative of the original structure is a difficult task. Model updating is a branch of optimization which calibrates the FE model by comparing the modal properties of the actual structure with these of the FE predictions. As the number of experimental measurements is usually much smaller than the number of uncertain parameters, and, consequently, not all uncertain parameters are selected for model updating, different local minima may exist in the solution space. Experimental noise further exacerbates the problem. The attainment of a global solution in a multi-dimensional search space is a challenging problem. Global optimization algorithms (GOAs) have received interest in the previous decade to solve this problem, but no GOA can ensure the detection of the global minimum either. To counter this problem, a combination of GOA with sequential niche technique (SNT) has been proposed in this research which systematically searches the whole solution space. A dynamically tested full scale pedestrian bridge is taken as a case study. Two different GOAs, namely particle swarm optimization (PSO) and genetic algorithm (GA), are investigated in combination with SNT. The results of these GOA are compared in terms of their efficiency in detecting global minima. The systematic search enables to find different solutions in the search space, thus increasing the confidence of finding the global minimum.

  20. Highly sensitive focus monitoring technique based on illumination and target co-optimization

    NASA Astrophysics Data System (ADS)

    Lee, Myungjun; Smith, Mark D.; Subrahmanyan, Pradeep; Levy, Ady

    2016-03-01

    We present a cost-effective focus monitoring technique based on the illumination and the target co-optimization. An advanced immersion scanner can provide the freeform illumination that enables the use of any kind of custom source shape by using a programmable array of thousands of individually adjustable micro-mirrors. Therefore, one can produce non-telecentricity using the asymmetric illumination in the scanner with the optimized focus target on the cost-effective binary OMOG mask. Then, the scanner focus variations directly translate into easily measurable overlay shifts in the printed pattern with high sensitivity (ΔShift/Δfocus = 60nm/100nm). In addition, the capability of using the freeform illumination allows us to computationally co-optimize the source and the focus target, simultaneously, generating not only vertical or horizontal shifts, but also introducing diagonal pattern shifts. The focus-induced pattern shifts can be accurately measured by standard wafer metrology tools such as CD-SEM and overlay metrology tools.

  1. Application of Singular Value Decomposition and Regularization Techniques for Optimization of a Highly Parameterized FEFLOW Model

    NASA Astrophysics Data System (ADS)

    Andrachek, R. G.; Abbey, D.; James, S. C.; Zhang, B.; Gabriel, C.; Martin, P.; Arnold, B. W.; Woessner, W. W.

    2009-12-01

    Groundwater flow predictions in complex geologic environments require the use of models that represent all potentially important physical features. Oversimplification of the flow system may neglect features that are important to understanding the range of possible flow predictions. FEFLOW was used to develop an equivalent porous medium model representing all of the key features of the conceptual model describing a folded and faulted fractured rock environment located in Southern California, USA. FEFLOW allows dipping layers with layer parallel anisotropy, vertical faults, and decreasing hydraulic conductivity with depth. The variably-saturated flow model consists of 46 layers and 1,245 parameters supported by 302 point observations of heads, head differences, pumping rates and seepage flow. The flow solution was optimized using Singular Value Decomposition and Tikhonov Regularization techniques implemented in the SVD-Assist tool within PEST. Optimization improved the model fit significantly; the objective function was reduced by 80% from its initial value. The optimized model retains sufficient parameter detail to predict flow directions. Moreover, the analysis can be extended to facilitate a probability-based assessment of flow prediction uncertainty.

  2. Reducing the impact of a desalination plant using stochastic modeling and optimization techniques

    NASA Astrophysics Data System (ADS)

    Alcolea, Andres; Renard, Philippe; Mariethoz, Gregoire; Bertone, François

    2009-02-01

    SummaryWater is critical for economic growth in coastal areas. In this context, desalination has become an increasingly important technology over the last five decades. It often has environmental side effects, especially when the input water is pumped directly from the sea via intake pipelines. However, it is generally more efficient and cheaper to desalt brackish groundwater from beach wells rather than desalting seawater. Natural attenuation is also gained and hazards due to anthropogenic pollution of seawater are reduced. In order to minimize allocation and operational costs and impacts on groundwater resources, an optimum pumping network is required. Optimization techniques are often applied to this end. Because of aquifer heterogeneity, designing the optimum pumping network demands reliable characterizations of aquifer parameters. An optimum pumping network in a coastal aquifer in Oman, where a desalination plant currently pumps brackish groundwater at a rate of 1200 m 3/h for a freshwater production of 504 m 3/h (insufficient to satisfy the growing demand in the area) was designed using stochastic inverse modeling together with optimization techniques. The Monte Carlo analysis of 200 simulations of transmissivity and storage coefficient fields conditioned to the response to stresses of tidal fluctuation and three long term pumping tests was performed. These simulations are physically plausible and fit the available data well. Simulated transmissivity fields are used to design the optimum pumping configuration required to increase the current pumping rate to 9000 m 3/h, for a freshwater production of 3346 m 3/h (more than six times larger than the existing one). For this task, new pumping wells need to be sited and their pumping rates defined. These unknowns are determined by a genetic algorithm that minimizes a function accounting for: (1) drilling, operational and maintenance costs, (2) target discharge and minimum drawdown (i.e., minimum aquifer

  3. Current concepts in surgical treatment of osteosarcoma

    PubMed Central

    Tiwari, Akshay

    2012-01-01

    Osteosarcoma is the most common malignant primary neoplasm of bone. For an optimal oncological outcome, surgical removal of tumor is an essential component of its multidisciplinary treatment. Limb salvage surgery has long been established as the standard of care for osteosarcoma. While limb-salvaging techniques have acceptable rates of disease control, amputation remains a valid procedure in selected cases. In current orthopedic oncology practice, the focus is on optimizing the balance between preservation of form and function of the limb and adequate oncological clearance at the same time. Improving the functional outcome and longevity of reconstructive procedures also remains a challenge. PMID:25983449

  4. Optimal technique of linear accelerator-based stereotactic radiosurgery for tumors adjacent to brainstem.

    PubMed

    Chang, Chiou-Shiung; Hwang, Jing-Min; Tai, Po-An; Chang, You-Kang; Wang, Yu-Nong; Shih, Rompin; Chuang, Keh-Shih

    2016-01-01

    either DCA or IMRS plans, at 9.2 ± 7% and 8.2 ± 6%, respectively. Owing to the multiple arc or beam planning designs of IMRS and VMAT, both of these techniques required higher MU delivery than DCA, with the averages being twice as high (p < 0.05). If linear accelerator is only 1 modality can to establish for SRS treatment. Based on statistical evidence retrospectively, we recommend VMAT as the optimal technique for delivering treatment to tumors adjacent to brainstem. PMID:27396940

  5. Good techniques optimize control of oil-based mud and solids

    SciTech Connect

    Phelps, J.; Hoopingarner, J.

    1989-02-13

    Effective techniques have been developed from work on dozens of North Sea Wells to minimize the amount of oil-based mud discharged to the sea while maintaining acceptable levels of solids. Pressure to reduce pollution during the course of drilling prompted the development of these techniques. They involve personnel and optimization of mud system and procedures. Case histories demonstrate that regulations may be met with economical techniques using existing technology. The benefits of low solids content are widely known, and are a key part of any successful mud program. Good solids control should result in lower mud costs and better drilling performance. Operators have specified high-performance shakers to accomplish this and have revised their mud programs with lower and lower allowable drilled solids percentages. This will pay off in certain areas. But with the U.K. Department of Energy regulations requiring cuttings oil discharge content (CODC) to be less than 150 g of oil/kg of dry solids discharge that went into effect Jan. 1, 1989, oil-loss control has a higher profile in the U.K. sector of the North Sea.

  6. Dose reduction in a paediatric X-ray department following optimization of radiographic technique.

    PubMed

    Mooney, R; Thomas, P S

    1998-08-01

    A survey of radiation doses to children from diagnostic radiography has been carried out in a dedicated paediatric X-ray room. Entrance surface dose (ESD) and dose-area product (DAP) per radiograph were simultaneously measured with thermoluminescent dosemeters (TLDs) and a DAP meter to provide mean dose values for separate age ranges. Results of ESD and DAP were lower than the mean values from other UK studies for all ages and radiographs, except for the infant pelvis AP radiograph. Comparison of ESD and radiographic technique with CEC quality criteria highlighted a need for reduction of dose to infants and implied an increase in tube filtration might overcome the limitations of the room's three-phase, 12-pulse generator, allowing higher tube potentials to be used on infants. Additional tube filtration of 3 mmA1 was installed following assessment of dose reduction and image quality with test objects and phantoms, and confirmation from the paediatric radiologist that clinical image quality was not-significantly altered. The tube potential was increased from 50 to 56 kVp for the infant pelvis AP radiograph. The resulting ESD and effective dose fell by 51% and 38%, respectively. The CEC quality criteria have proved useful as a benchmark against which technique in X-ray departments can be compared, and as such are a useful tool for optimizing radiographic technique and reducing patient dose.

  7. Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique

    PubMed Central

    Karthivashan, Govindarajan; Masarudin, Mas Jaffri; Kura, Aminu Umar; Abas, Faridah; Fakurazi, Sharida

    2016-01-01

    This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as “flavonosome”. Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA–phosphatidylcholine) through four different methods of synthesis – bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug–carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA–phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of −39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a

  8. Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique.

    PubMed

    Karthivashan, Govindarajan; Masarudin, Mas Jaffri; Kura, Aminu Umar; Abas, Faridah; Fakurazi, Sharida

    2016-01-01

    This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as "flavonosome". Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA-phosphatidylcholine) through four different methods of synthesis - bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug-carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA-phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of -39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising

  9. Recursive Ant Colony Global Optimization: a new technique for the inversion of geophysical data

    NASA Astrophysics Data System (ADS)

    Gupta, D. K.; Gupta, J. P.; Arora, Y.; Singh, U. K.

    2011-12-01

    We present a new method called Recursive Ant Colony Global Optimization (RACO) technique, a modified form of general ACO, which can be used to find the best solutions to inversion problems in geophysics. RACO simulates the social behaviour of ants to find the best path between the nest and the food source. A new term depth has been introduced, which controls the extent of recursion. A selective number of cities get qualified for the successive depth. The results of one depth are used to construct the models for the next depth and the range of values for each of the parameters is reduced without any change to the number of models. The three additional steps performed after each depth, are the pheromone tracking, pheromone updating and city selection. One of the advantages of RACO over ACO is that if a problem has multiple solutions, then pheromone accumulation will take place at more than one city thereby leading to formation of multiple nested ACO loops within the ACO loop of the previous depth. Also, while the convergence of ACO is almost linear, RACO shows exponential convergence and hence is faster than the ACO. RACO proves better over some other global optimization techniques, as it does not require any initial values to be assigned to the parameters function. The method has been tested on some mathematical functions, synthetic self-potential (SP) and synthetic gravity data. The obtained results reveal the efficiency and practicability of the method. The method is found to be efficient enough to solve the problems of SP and gravity anomalies due to a horizontal cylinder, a sphere, an inclined sheet and multiple idealized bodies buried inside the earth. These anomalies with and without noise were inverted using the RACO algorithm. The obtained results were compared with those obtained from the conventional methods and it was found that RACO results are more accurate. Finally this optimization technique was applied to real field data collected over the Surda

  10. A Study on the Complications of Surgical Treatment for Bilateral Developmental Dysplasia of the Hip and A Comparison of Two Osteotomy Techniques

    PubMed Central

    Ezirmik, Naci; Yildiz, Kadri

    2011-01-01

    Objective: This study aims to present a review about complications of surgical treatment of Developmental Dysplasia of the Hip and comparing the kinds and ratios of two osteotomy technique (Salter Innominate Osteotomy and Pemberton Pericapsular Osteotomy). Materials and Methods: Fifty-seven patients of 126 that had bilateral developmental dysplasia of the hip are the case series that had undewent to Salter Innominate Osteotomy for one hip and Pemberton Pericapsular Osteotomy for other hip by one surgeon in one stage. Results: Avascular Necrosis ratio was 19.29% on hips with Salter Innominate Osteotomy, and 8.77% on hips with Pemberton Pericapsular Osteotomy. Salter Innominate Osteotomy made lower limb discrepency with 0.47 cm mean in all patients. There were 17 general complications on hips with Salter Innominate Osteotomy (SIO) (14.91%) and 9 general complications on hip with Pemberton Pericapsular Osteotomy (PPO) (7.89%). As looking for general complications, SIO/PPO ratio were 1.8 (17/9). Conclusion: By the comparing two osteotomy technique for complication ratios, SIO had two-fold of complications than PPO. SIO had 65% more complications as to PPO. PMID:25610185

  11. Multiscale Surgical Telerobots

    SciTech Connect

    Miles, R R; Seward, K P; Benett, W J; Tendick, F; Bentley, L; Stephan, P L

    2002-01-23

    A project was undertaken to improve robotic surgical tools for telerobotic minimally invasive surgery. The major objectives were to reduce the size of the tools to permit new surgical procedures in confined spaces such as the heart and to improve control of surgical tools by locating positional sensors and actuators at the end effector rather than external to the patient as is currently the state of the technology. A new compact end-effector with wrist-like flexibility was designed. Positional sensors based on MEMS microfabrication techniques were designed.

  12. Surgical correction of brachymetatarsia.

    PubMed

    Bartolomei, F J

    1990-02-01

    Brachymetatarsia describes the condition of an abnormally short metatarsal. Although the condition has been recorded since antiquity, surgical options to correct the deformity have been available for only two decades. Most published procedures involve metaphyseal lengthening with autogenous grafts from different donor sites. The author discusses one such surgical technique. In addition, the author proposes specific criteria for the objective diagnosis of brachymetatarsia. PMID:2406417

  13. Robust breathing signal extraction from cone beam CT projections based on adaptive and global optimization techniques.

    PubMed

    Chao, Ming; Wei, Jie; Li, Tianfang; Yuan, Yading; Rosenzweig, Kenneth E; Lo, Yeh-Chi

    2016-04-21

    We present a study of extracting respiratory signals from cone beam computed tomography (CBCT) projections within the framework of the Amsterdam Shroud (AS) technique. Acquired prior to the radiotherapy treatment, CBCT projections were preprocessed for contrast enhancement by converting the original intensity images to attenuation images with which the AS image was created. An adaptive robust z-normalization filtering was applied to further augment the weak oscillating structures locally. From the enhanced AS image, the respiratory signal was extracted using a two-step optimization approach to effectively reveal the large-scale regularity of the breathing signals. CBCT projection images from five patients acquired with the Varian Onboard Imager on the Clinac iX System Linear Accelerator (Varian Medical Systems, Palo Alto, CA) were employed to assess the proposed technique. Stable breathing signals can be reliably extracted using the proposed algorithm. Reference waveforms obtained using an air bellows belt (Philips Medical Systems, Cleveland, OH) were exported and compared to those with the AS based signals. The average errors for the enrolled patients between the estimated breath per minute (bpm) and the reference waveform bpm can be as low as -0.07 with the standard deviation 1.58. The new algorithm outperformed the original AS technique for all patients by 8.5% to 30%. The impact of gantry rotation on the breathing signal was assessed with data acquired with a Quasar phantom (Modus Medical Devices Inc., London, Canada) and found to be minimal on the signal frequency. The new technique developed in this work will provide a practical solution to rendering markerless breathing signal using the CBCT projections for thoracic and abdominal patients.

  14. Robust breathing signal extraction from cone beam CT projections based on adaptive and global optimization techniques

    NASA Astrophysics Data System (ADS)

    Chao, Ming; Wei, Jie; Li, Tianfang; Yuan, Yading; Rosenzweig, Kenneth E.; Lo, Yeh-Chi

    2016-04-01

    We present a study of extracting respiratory signals from cone beam computed tomography (CBCT) projections within the framework of the Amsterdam Shroud (AS) technique. Acquired prior to the radiotherapy treatment, CBCT projections were preprocessed for contrast enhancement by converting the original intensity images to attenuation images with which the AS image was created. An adaptive robust z-normalization filtering was applied to further augment the weak oscillating structures locally. From the enhanced AS image, the respiratory signal was extracted using a two-step optimization approach to effectively reveal the large-scale regularity of the breathing signals. CBCT projection images from five patients acquired with the Varian Onboard Imager on the Clinac iX System Linear Accelerator (Varian Medical Systems, Palo Alto, CA) were employed to assess the proposed technique. Stable breathing signals can be reliably extracted using the proposed algorithm. Reference waveforms obtained using an air bellows belt (Philips Medical Systems, Cleveland, OH) were exported and compared to those with the AS based signals. The average errors for the enrolled patients between the estimated breath per minute (bpm) and the reference waveform bpm can be as low as  -0.07 with the standard deviation 1.58. The new algorithm outperformed the original AS technique for all patients by 8.5% to 30%. The impact of gantry rotation on the breathing signal was assessed with data acquired with a Quasar phantom (Modus Medical Devices Inc., London, Canada) and found to be minimal on the signal frequency. The new technique developed in this work will provide a practical solution to rendering markerless breathing signal using the CBCT projections for thoracic and abdominal patients.

  15. Robust breathing signal extraction from cone beam CT projections based on adaptive and global optimization techniques.

    PubMed

    Chao, Ming; Wei, Jie; Li, Tianfang; Yuan, Yading; Rosenzweig, Kenneth E; Lo, Yeh-Chi

    2016-04-21

    We present a study of extracting respiratory signals from cone beam computed tomography (CBCT) projections within the framework of the Amsterdam Shroud (AS) technique. Acquired prior to the radiotherapy treatment, CBCT projections were preprocessed for contrast enhancement by converting the original intensity images to attenuation images with which the AS image was created. An adaptive robust z-normalization filtering was applied to further augment the weak oscillating structures locally. From the enhanced AS image, the respiratory signal was extracted using a two-step optimization approach to effectively reveal the large-scale regularity of the breathing signals. CBCT projection images from five patients acquired with the Varian Onboard Imager on the Clinac iX System Linear Accelerator (Varian Medical Systems, Palo Alto, CA) were employed to assess the proposed technique. Stable breathing signals can be reliably extracted using the proposed algorithm. Reference waveforms obtained using an air bellows belt (Philips Medical Systems, Cleveland, OH) were exported and compared to those with the AS based signals. The average errors for the enrolled patients between the estimated breath per minute (bpm) and the reference waveform bpm can be as low as -0.07 with the standard deviation 1.58. The new algorithm outperformed the original AS technique for all patients by 8.5% to 30%. The impact of gantry rotation on the breathing signal was assessed with data acquired with a Quasar phantom (Modus Medical Devices Inc., London, Canada) and found to be minimal on the signal frequency. The new technique developed in this work will provide a practical solution to rendering markerless breathing signal using the CBCT projections for thoracic and abdominal patients. PMID:27008349

  16. Evaluation and optimization of the structural parameter of diesel nozzle basing on synchrotron radiation imaging techniques

    NASA Astrophysics Data System (ADS)

    Wu, Z.; Gao, Y.; Gong, H.; Li, L.

    2016-04-01

    Lacking of efficient methods, industry currently uses one only parameter—fuel flow rate—to evaluate the nozzle quality, which is far from satisfying the current emission regulations worldwide. By utilizing synchrotron radiation high energy X-ray in Shanghai Synchrotron Radiation Facility (SSRF), together with the imaging techniques, the 3D models of two nozzles with the same design dimensions were established, and the influence of parameters fluctuation in the azimuthal direction were analyzed in detail. Results indicate that, due to the orifice misalignment, even with the same design dimension, the inlet rounding radius of orifices differs greatly, and its fluctuation in azimuthal direction is also large. This difference will cause variation in the flow characteristics at orifice outlet and then further affect the spray characteristics. The study also indicates that, more precise investigation and insight into the evaluation and optimization of diesel nozzle structural parameter are needed.

  17. Optimization of a wood dryer kiln using the mixed integer programming technique: A case study

    SciTech Connect

    Gustafsson, S.I.

    1999-07-01

    When wood is to be utilized as a raw material for furniture, buildings, etc., it must be dried from approximately 100% to 6% moisture content. This is achieved at least partly in a drying kiln. Heat for this purpose is provided by electrical means, or by steam from boilers fired with wood chips or oil. By making a close examination of monitored values from an actual drying kiln it has been possible to optimize the use of steam and electricity using the so called mixed integer programming technique. Owing to the operating schedule for the drying kiln it has been necessary to divide the drying process in very short time intervals, i.e., a number of minutes. Since a drying cycle takes about two or three weeks, a considerable mathematical problem is presented and this has to be solved.

  18. Review of ventilatory techniques to optimize mechanical ventilation in acute exacerbation of chronic obstructive pulmonary disease

    PubMed Central

    Reddy, Raghu M; Guntupalli, Kalpalatha K

    2007-01-01

    Chronic obstructive pulmonary disease (COPD) is a major global healthcare problem. Studies vary widely in the reported frequency of mechanical ventilation in acute exacerbations of COPD. Invasive intubation and mechanical ventilation may be associated with significant morbidity and mortality. A good understanding of the airway pathophysiology and lung mechanics in COPD is necessary to appropriately manage acute exacerbations and respiratory failure. The basic pathophysiology in COPD exacerbation is the critical expiratory airflow limitation with consequent dynamic hyperinflation. These changes lead to further derangement in ventilatory mechanics, muscle function and gas exchange which may result in respiratory failure. This review discusses the altered respiratory mechanics in COPD, ways to detect these changes in a ventilated patient and formulating ventilatory techniques to optimize management of respiratory failure due to exacerbation of COPD. PMID:18268918

  19. Probabilistic risk assessment techniques help in identifying optimal equipment design for in-situ vitrification

    SciTech Connect

    Lucero, V.; Meale, B.M.; Purser, F.E.

    1990-01-01

    The analysis discussed in this paper was performed as part of the buried waste remediation efforts at the Idaho National Engineering Laboratory (INEL). The specific type of remediation discussed herein involves a thermal treatment process for converting contaminated soil and waste into a stable, chemically-inert form. Models of the proposed process were developed using probabilistic risk assessment (PRA) fault tree and event tree modeling techniques. The models were used to determine the appropriateness of the conceptual design by identifying potential hazards of system operations. Additional models were developed to represent the reliability aspects of the system components. By performing various sensitivities with the models, optimal design modifications are being identified to substantiate an integrated, cost-effective design representing minimal risk to the environment and/or public with maximum component reliability. 4 figs.

  20. Engine Yaw Augmentation for Hybrid-Wing-Body Aircraft via Optimal Control Allocation Techniques

    NASA Technical Reports Server (NTRS)

    Taylor, Brian R.; Yoo, Seung Yeun

    2011-01-01

    Asymmetric engine thrust was implemented in a hybrid-wing-body non-linear simulation to reduce the amount of aerodynamic surface deflection required for yaw stability and control. Hybrid-wing-body aircraft are especially susceptible to yaw surface deflection due to their decreased bare airframe yaw stability resulting from the lack of a large vertical tail aft of the center of gravity. Reduced surface deflection, especially for trim during cruise flight, could reduce the fuel consumption of future aircraft. Designed as an add-on, optimal control allocation techniques were used to create a control law that tracks total thrust and yaw moment commands with an emphasis on not degrading the baseline system. Implementation of engine yaw augmentation is shown and feasibility is demonstrated in simulation with a potential drag reduction of 2 to 4 percent. Future flight tests are planned to demonstrate feasibility in a flight environment.

  1. Optimization of numerical weather/wave prediction models based on information geometry and computational techniques

    NASA Astrophysics Data System (ADS)

    Galanis, George; Famelis, Ioannis; Kalogeri, Christina

    2014-10-01

    The last years a new highly demanding framework has been set for environmental sciences and applied mathematics as a result of the needs posed by issues that are of interest not only of the scientific community but of today's society in general: global warming, renewable resources of energy, natural hazards can be listed among them. Two are the main directions that the research community follows today in order to address the above problems: The utilization of environmental observations obtained from in situ or remote sensing sources and the meteorological-oceanographic simulations based on physical-mathematical models. In particular, trying to reach credible local forecasts the two previous data sources are combined by algorithms that are essentially based on optimization processes. The conventional approaches in this framework usually neglect the topological-geometrical properties of the space of the data under study by adopting least square methods based on classical Euclidean geometry tools. In the present work new optimization techniques are discussed making use of methodologies from a rapidly advancing branch of applied Mathematics, the Information Geometry. The latter prove that the distributions of data sets are elements of non-Euclidean structures in which the underlying geometry may differ significantly from the classical one. Geometrical entities like Riemannian metrics, distances, curvature and affine connections are utilized in order to define the optimum distributions fitting to the environmental data at specific areas and to form differential systems that describes the optimization procedures. The methodology proposed is clarified by an application for wind speed forecasts in the Kefaloniaisland, Greece.

  2. Optimization of GPS water vapor tomography technique with radiosonde and COSMIC historical data

    NASA Astrophysics Data System (ADS)

    Ye, Shirong; Xia, Pengfei; Cai, Changsheng

    2016-09-01

    The near-real-time high spatial resolution of atmospheric water vapor distribution is vital in numerical weather prediction. GPS tomography technique has been proved effectively for three-dimensional water vapor reconstruction. In this study, the tomography processing is optimized in a few aspects by the aid of radiosonde and COSMIC historical data. Firstly, regional tropospheric zenith hydrostatic delay (ZHD) models are improved and thus the zenith wet delay (ZWD) can be obtained at a higher accuracy. Secondly, the regional conversion factor of converting the ZWD to the precipitable water vapor (PWV) is refined. Next, we develop a new method for dividing the tomography grid with an uneven voxel height and a varied water vapor layer top. Finally, we propose a Gaussian exponential vertical interpolation method which can better reflect the vertical variation characteristic of water vapor. GPS datasets collected in Hong Kong in February 2014 are employed to evaluate the optimized tomographic method by contrast with the conventional method. The radiosonde-derived and COSMIC-derived water vapor densities are utilized as references to evaluate the tomographic results. Using radiosonde products as references, the test results obtained from our optimized method indicate that the water vapor density accuracy is improved by 15 and 12 % compared to those derived from the conventional method below the height of 3.75 km and above the height of 3.75 km, respectively. Using the COSMIC products as references, the results indicate that the water vapor density accuracy is improved by 15 and 19 % below 3.75 km and above 3.75 km, respectively.

  3. Trends in the Surgical Correction of Gynecomastia

    PubMed Central

    Brown, Rodger H.; Chang, Daniel K.; Siy, Richard; Friedman, Jeffrey

    2015-01-01

    Gynecomastia refers to the enlargement of the male breast due to a proliferation of ductal, stromal, and/or fatty tissue. Although it is a common condition affecting up to 65% of men, not all cases require surgical intervention. Contemporary surgical techniques in the treatment of gynecomastia have become increasingly less invasive with the advent of liposuction and its variants, including power-assisted and ultrasound-assisted liposuction. These techniques, however, have been largely limited in their inability to address significant skin excess and ptosis. For mild to moderate gynecomastia, newer techniques using arthroscopic morcellation and endoscopic techniques promise to address the fibrous component, while minimizing scar burden by utilizing liposuction incisions. Nevertheless, direct excision through periareolar incisions remains a mainstay in treatment algorithms for its simplicity and avoidance of additional instrumentation. This is particularly true for more severe cases of gynecomastia requiring skin resection. In the most severe cases with significant skin redundancy and ptosis, breast amputation with free nipple grafting remains an effective option. Surgical treatment should be individualized to each patient, combining techniques to provide adequate resection and optimize aesthetic results. PMID:26528088

  4. Optimal spatial sampling techniques for ground truth data in microwave remote sensing of soil moisture

    NASA Technical Reports Server (NTRS)

    Rao, R. G. S.; Ulaby, F. T.

    1977-01-01

    The paper examines optimal sampling techniques for obtaining accurate spatial averages of soil moisture, at various depths and for cell sizes in the range 2.5-40 acres, with a minimum number of samples. Both simple random sampling and stratified sampling procedures are used to reach a set of recommended sample sizes for each depth and for each cell size. Major conclusions from statistical sampling test results are that (1) the number of samples required decreases with increasing depth; (2) when the total number of samples cannot be prespecified or the moisture in only one single layer is of interest, then a simple random sample procedure should be used which is based on the observed mean and SD for data from a single field; (3) when the total number of samples can be prespecified and the objective is to measure the soil moisture profile with depth, then stratified random sampling based on optimal allocation should be used; and (4) decreasing the sensor resolution cell size leads to fairly large decreases in samples sizes with stratified sampling procedures, whereas only a moderate decrease is obtained in simple random sampling procedures.

  5. Revisiting fixation and embedding techniques for optimal detection of dendritic cell subsets in tissues.

    PubMed

    Accart, Nathalie; Sergi, Florinda; Rooke, Ronald

    2014-09-01

    Organ-specific cell types are maintained by tissue homeostasis and may vary in nature and/or frequency in pathological situations. Moreover, within a cell lineage, some sub-populations, defined by combinations of cell-surface markers, may have specific functions. Dendritic cells are the epitome of such a population as they may be subdivided into discrete sub-groups with defined functions in specific compartments of various organs. Technically, to study the distribution of DC sub-populations, it involves performing multiparametric immunofluorescence on well-conserved organ structures. However, immunodetection may be impacted by protein cross-linking and antigenic epitope masking by the use of 10% neutral-buffered formalin. To circumvent this and to preserve a good morphological tissue structure, we evaluated alternative fixatives such as Periodate Lysine Paraformaldehyde or Tris Zinc fixatives in combination with other embedding techniques. The cryosection protocols were adapted for optimal antigen detection but offered a poor morphological preservation. We therefore developed a new methodology based on Tris Zinc fixative, gelatin-sucrose embedding and freezing. Using multiple DC markers, we demonstrate that this treatment is an optimal protocol for cell-surface marker detection on high-quality tissue sections. PMID:24874853

  6. A novel built-up spectral index developed by using multiobjective particle-swarm-optimization technique

    NASA Astrophysics Data System (ADS)

    Sameen, Maher Ibrahim; Pradhan, Biswajeet

    2016-06-01

    In this study, we propose a novel built-up spectral index which was developed by using particle-swarm-optimization (PSO) technique for Worldview-2 images. PSO was used to select the relevant bands from the eight (8) spectral bands of Worldview-2 image and then were used for index development. Multiobiective optimization was used to minimize the number of selected spectral bands and to maximize the classification accuracy. The results showed that the most important and relevant spectral bands among the eight (8) bands for built-up area extraction are band4 (yellow) and band7 (NIR1). Using those relevant spectral bands, the final spectral index was form ulated by developing a normalized band ratio. The validation of the classification result using the proposed spectral index showed that our novel spectral index performs well compared to the existing WV -BI index. The accuracy assessment showed that the new proposed spectral index could extract built-up areas from Worldview-2 image with an area under curve (AUC) of (0.76) indicating the effectiveness of the developed spectral index. Further improvement could be done by using several datasets during the index development process to ensure the transferability of the index to other datasets and study areas.

  7. Optimization of electrospinning techniques for the realization of nanofiber plastic lasers

    NASA Astrophysics Data System (ADS)

    Persano, L.; Moffa, M.; Fasano, V.; Montinaro, M.; Morello, G.; Resta, V.; Spadaro, D.; Gucciardi, P. G.; Maragò, O. M.; Camposeo, A.; Pisignano, D.

    2016-02-01

    Electrospinning technologies for the realization of active polymeric nanomaterials can be easily up-scaled, opening perspectives to industrial exploitation, and due to their versatility they can be employed to finely tailor the size, morphology and macroscopic assembly of fibers as well as their functional properties. Light-emitting or other active polymer nanofibers, made of conjugated polymers or of blends embedding chromophores or other functional dopants, are suitable for various applications in advanced photonics and sensing technologies. In particular, their almost onedimensional geometry and finely tunable composition make them interesting materials for developing novel lasing devices. However, electrospinning techniques rely on a large variety of parameters and possible experimental geometries, and they need to be carefully optimized in order to obtain suitable topographical and photonic properties in the resulting nanostructures. Targeted features include smooth and uniform fiber surface, dimensional control, as well as filament alignment, enhanced light emission, and stimulated emission. We here present various optimization strategies for electrospinning methods which have been implemented and developed by us for the realization of lasing architectures based on polymer nanofibers. The geometry of the resulting nanowires leads to peculiar light-scattering from spun filaments, and to controllable lasing characteristics.

  8. AI techniques for optimizing multi-objective reservoir operation upon human and riverine ecosystem demands

    NASA Astrophysics Data System (ADS)

    Tsai, Wen-Ping; Chang, Fi-John; Chang, Li-Chiu; Herricks, Edwin E.

    2015-11-01

    Flow regime is the key driver of the riverine ecology. This study proposes a novel hybrid methodology based on artificial intelligence (AI) techniques for quantifying riverine ecosystems requirements and delivering suitable flow regimes that sustain river and floodplain ecology through optimizing reservoir operation. This approach addresses issues to better fit riverine ecosystem requirements with existing human demands. We first explored and characterized the relationship between flow regimes and fish communities through a hybrid artificial neural network (ANN). Then the non-dominated sorting genetic algorithm II (NSGA-II) was established for river flow management over the Shihmen Reservoir in northern Taiwan. The ecosystem requirement took the form of maximizing fish diversity, which could be estimated by the hybrid ANN. The human requirement was to provide a higher satisfaction degree of water supply. The results demonstrated that the proposed methodology could offer a number of diversified alternative strategies for reservoir operation and improve reservoir operational strategies producing downstream flows that could meet both human and ecosystem needs. Applications that make this methodology attractive to water resources managers benefit from the wide spread of Pareto-front (optimal) solutions allowing decision makers to easily determine the best compromise through the trade-off between reservoir operational strategies for human and ecosystem needs.

  9. Flexor Carpi Radialis to Palmaris Longus Tendon Transfer for Spontaneous Rupture of the Flexor Carpi Radialis Tendon-A Review of an Uncommon Finding and Surgical Technique for Operative Correction.

    PubMed

    Shearin, Jonathan Winkworth; Walters, Brian; Yang, S Steven

    2016-10-01

    Spontaneous ruptures of the flexor carpi radialis tendon (FCR) are rare and associated with systemic inflammatory diseases, localized tendinopathy related to scaphotrapezial-trapezoidal arthritis, or chronic immunosuppression from corticosteroids. While most cases do not require operative intervention, some patients develop weakness, impaired range of motion, and persistent pain. Previously reported surgical options include synovectomy, tendon stump resection, and osteophyte removal. We describe a surgical technique for patients with persistent symptomatology following FCR rupture in which the FCR is transposed end-to-side to the palmaris longus tendon. Three cases using this technique are presented with follow-up of 4-9 months that were collected at Lenox Hill Hospital. All three patients did well regarding specific outcome measures: grip strength, range of motion, and functional activity. FCR transfer to palmaris is an alternative to other surgical options for the spontaneous rupture of the FCR tendon in patients who remain symptomatic despite a course of non-operative therapy. PMID:27595965

  10. Surgical Scar Revision: An Overview

    PubMed Central

    Garg, Shilpa; Dahiya, Naveen; Gupta, Somesh

    2014-01-01

    Scar formation is an inevitable consequence of wound healing from either a traumatic or a surgical intervention. The aesthetic appearance of a scar is the most important criteria to judge the surgical outcome. An understanding of the anatomy and wound healing along with experience, meticulous planning and technique can reduce complications and improve the surgical outcome. Scar revision does not erase a scar but helps to make it less noticeable and more acceptable. Both surgical and non-surgical techniques, used either alone or in combination can be used for revising a scar. In planning a scar revision surgeon should decide on when to act and the type of technique to use for scar revision to get an aesthetically pleasing outcome. This review article provides overview of methods applied for facial scar revision. This predominantly covers surgical methods. PMID:24761092

  11. Using Interior Point Method Optimization Techniques to Improve 2- and 3-Dimensional Models of Earth Structures

    NASA Astrophysics Data System (ADS)

    Zamora, A.; Gutierrez, A. E.; Velasco, A. A.

    2014-12-01

    2- and 3-Dimensional models obtained from the inversion of geophysical data are widely used to represent the structural composition of the Earth and to constrain independent models obtained from other geological data (e.g. core samples, seismic surveys, etc.). However, inverse modeling of gravity data presents a very unstable and ill-posed mathematical problem, given that solutions are non-unique and small changes in parameters (position and density contrast of an anomalous body) can highly impact the resulting model. Through the implementation of an interior-point method constrained optimization technique, we improve the 2-D and 3-D models of Earth structures representing known density contrasts mapping anomalous bodies in uniform regions and boundaries between layers in layered environments. The proposed techniques are applied to synthetic data and gravitational data obtained from the Rio Grande Rift and the Cooper Flat Mine region located in Sierra County, New Mexico. Specifically, we improve the 2- and 3-D Earth models by getting rid of unacceptable solutions (those that do not satisfy the required constraints or are geologically unfeasible) given the reduction of the solution space.

  12. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    PubMed Central

    Tran, Cuong D.; Gopalsamy, Geetha L.; Mortimer, Elissa K.; Young, Graeme P.

    2015-01-01

    It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease. PMID:26035248

  13. Improving the performance of mass-consistent numerical models using optimization techniques

    SciTech Connect

    Barnard, J.C.; Wegley, H.L.; Hiester, T.R.

    1985-09-01

    This report describes a technique of using a mass-consistent model to derive wind speeds over a microscale region of complex terrain. A serious limitation in the use of these numerical models is that the calculated wind field is highly sensitive to some input parameters, such as those specifying atmospheric stability. Because accurate values for these parameters are not usually known, confidence in the calculated winds is low. However, values for these parameters can be found by tuning the model to existing wind observations within a microscale area. This tuning is accomplished by using a single-variable, unconstrained optimization procedure that adjusts the unknown parameters so that the error between the observed winds and model calculations of these winds is minimized. Model verification is accomplished by using eight sets of hourly averaged wind data. These data are obtained from measurements made at approximately 30 sites covering a wind farm development in the Altamont Pass area. When the model is tuned to a small subset of the 30 sites, an accurate determination of the wind speeds was made for the remaining sites in six of the eight cases. (The two that failed were low wind speed cases.) Therefore, when this technique is used, numerical modeling shows great promise as a tool for microscale siting of wind turbines in complex terrain.

  14. Reconstructing source terms from atmospheric concentration measurements: Optimality analysis of an inversion technique

    NASA Astrophysics Data System (ADS)

    Turbelin, Grégory; Singh, Sarvesh Kumar; Issartel, Jean-Pierre

    2014-12-01

    In the event of an accidental or intentional contaminant release in the atmosphere, it is imperative, for managing emergency response, to diagnose the release parameters of the source from measured data. Reconstruction of the source information exploiting measured data is called an inverse problem. To solve such a problem, several techniques are currently being developed. The first part of this paper provides a detailed description of one of them, known as the renormalization method. This technique, proposed by Issartel (2005), has been derived using an approach different from that of standard inversion methods and gives a linear solution to the continuous Source Term Estimation (STE) problem. In the second part of this paper, the discrete counterpart of this method is presented. By using matrix notation, common in data assimilation and suitable for numerical computing, it is shown that the discrete renormalized solution belongs to a family of well-known inverse solutions (minimum weighted norm solutions), which can be computed by using the concept of generalized inverse operator. It is shown that, when the weight matrix satisfies the renormalization condition, this operator satisfies the criteria used in geophysics to define good inverses. Notably, by means of the Model Resolution Matrix (MRM) formalism, we demonstrate that the renormalized solution fulfils optimal properties for the localization of single point sources. Throughout the article, the main concepts are illustrated with data from a wind tunnel experiment conducted at the Environmental Flow Research Centre at the University of Surrey, UK.

  15. Flow and Mixture Optimization for a Fuel Stratification Engine Using PIV and PLIF Techniques

    NASA Astrophysics Data System (ADS)

    Li, Y.; Zhao, H.; Ma, T.

    2006-07-01

    This paper describes an application of PIV (particle image velocimetry) and two-tracer PLIF (planar laser-induced florescence) techniques to optimize the in-cylinder flow and to visualize two fuels distribution simultaneously for developing a fuel stratification engine. This research was carried out on a twin-spark four-valve SI engine. The PIV measurement results shows that a strong tumbling flow was produced in the cylinder as the intake valves were shrouded. The flow exhibited a symmetrical distribution in the plane perpendicular to the cylinder axis from the early stage of intake until the late stage of compression. This flow pattern helps to stratify the two fuels introduced from separate ports into two regions laterally. The stratification of fuels was observed visually by the two-tracer PLIF technique. During the PLIF measurement, two tracers, 3- pentanone and N, N-dimethylaniline (DMA), were doped into two fuels, hexane and iso-octane, respectively. Their fluorescence emissions were separated by two optical band-pass filters and recorded by a single ICCD camera simultaneously via an image doubling system. The PLIF measurement result shows that two fuels were well stratified.

  16. Fabrication of a surgical guide with help of a milling machine by ridge mapping method.

    PubMed

    Pattanaik, Seema; Pattanaik, Bikash K

    2013-03-01

    Optimizing the prosthetic result by customization of a surgical guide should be a major consideration in the implant placement. The design of the surgical guide must account for several factors, including position of the implant, the tissue present, and the anticipated prosthesis. The objective of this article is to present a technique for fabrication and customization of surgical guide with the help of ridge mapping procedure and a milling machine. This technique is helpful for the beginners in implant dentistry and for the dentists who cannot avail the CBCT/medical CT facilities.

  17. Surgical tracheotomy.

    PubMed

    Rowshan, Henry H; Baur, Dale A

    2010-03-01

    Tracheotomy is a surgical procedure that dates back to early history and medical advancement. The oral and maxillofacial surgeon routinely operates around the airway and should be able to master this procedure by adhering to the surgical principles outlined in this article.

  18. Optimized fractional cloudiness determination from five ground-based remote sensing techniques

    SciTech Connect

    Boers, R.; de Haij, M. J.; Wauben, W.M.F.; Baltink, Henk K.; van Ulft, L. H.; Savenije, M.; Long, Charles N.

    2010-12-23

    A one-year record of fractional cloudiness at 10 minute intervals was generated for the Cabauw Experimental Site for Atmospheric Research [CESAR] (51°58’N, 4° 55’E) using an integrated assessment of five different observational methods. The five methods are based on active as well as passive systems and use either a hemispheric or column remote sensing technique. The one-year instrumental cloudiness data were compared against a 30 year climatology of Observer data in the vicinity of CESAR [1971- 2000]. In the intermediate 2 - 6 octa range, most instruments, but especially the column methods, report lower frequency of occurrence of cloudiness than the absolute minimum values from the 30 year Observer climatology. At night, the Observer records less clouds in the 1, 2 octa range than during the day, while the instruments registered more clouds. During daytime the Observer also records much more 7 octa cloudiness than the instruments. One column method combining a radar with a lidar outstrips all other techniques in recording cloudiness, even up to height in excess of 9 km. This is mostly due to the high sensitivity of the radar that is used in the technique. A reference algorithm was designed to derive a continuous and optimized record of fractional cloudiness. Output from individual instruments were weighted according to the cloud base height reported at the observation time; the larger the height, the lower the weight. The algorithm was able to provide fractional cloudiness observations every 10 minutes for 98% of the total period of 12 months [15 May 2008 - 14 May 2009].

  19. Hyoid bone development: An assessment of optimal CT scanner parameters and 3D volume rendering techniques

    PubMed Central

    Cotter, Meghan M.; Whyms, Brian J.; Kelly, Michael P.; Doherty, Benjamin M.; Gentry, Lindell R.; Bersu, Edward T.; Vorperian, Houri K.

    2015-01-01

    The hyoid bone anchors and supports the vocal tract. Its complex shape is best studied in three dimensions, but it is difficult to capture on computed tomography (CT) images and three-dimensional volume renderings. The goal of this study was to determine the optimal CT scanning and rendering parameters to accurately measure the growth and developmental anatomy of the hyoid and to determine whether it is feasible and necessary to use these parameters in the measurement of hyoids from in vivo CT scans. Direct linear and volumetric measurements of skeletonized hyoid bone specimens were compared to corresponding CT images to determine the most accurate scanning parameters and three-dimensional rendering techniques. A pilot study was undertaken using in vivo scans from a retrospective CT database to determine feasibility of quantifying hyoid growth. Scanning parameters and rendering technique affected accuracy of measurements. Most linear CT measurements were within 10% of direct measurements; however, volume was overestimated when CT scans were acquired with a slice thickness greater than 1.25 mm. Slice-by-slice thresholding of hyoid images decreased volume overestimation. The pilot study revealed that the linear measurements tested correlate with age. A fine-tuned rendering approach applied to small slice thickness CT scans produces the most accurate measurements of hyoid bones. However, linear measurements can be accurately assessed from in vivo CT scans at a larger slice thickness. Such findings imply that investigation into the growth and development of the hyoid bone, and the vocal tract as a whole, can now be performed using these techniques. PMID:25810349

  20. MODELING VERY LONG BASELINE INTERFEROMETRIC IMAGES WITH THE CROSS-ENTROPY GLOBAL OPTIMIZATION TECHNIQUE

    SciTech Connect

    Caproni, A.; Toffoli, R. T.; Monteiro, H.; Abraham, Z.; Teixeira, D. M.

    2011-07-20

    We present a new technique for obtaining model fittings to very long baseline interferometric images of astrophysical jets. The method minimizes a performance function proportional to the sum of the squared difference between the model and observed images. The model image is constructed by summing N{sub s} elliptical Gaussian sources characterized by six parameters: two-dimensional peak position, peak intensity, eccentricity, amplitude, and orientation angle of the major axis. We present results for the fitting of two main benchmark jets: the first constructed from three individual Gaussian sources, the second formed by five Gaussian sources. Both jets were analyzed by our cross-entropy technique in finite and infinite signal-to-noise regimes, the background noise chosen to mimic that found in interferometric radio maps. Those images were constructed to simulate most of the conditions encountered in interferometric images of active galactic nuclei. We show that the cross-entropy technique is capable of recovering the parameters of the sources with a similar accuracy to that obtained from the very traditional Astronomical Image Processing System Package task IMFIT when the image is relatively simple (e.g., few components). For more complex interferometric maps, our method displays superior performance in recovering the parameters of the jet components. Our methodology is also able to show quantitatively the number of individual components present in an image. An additional application of the cross-entropy technique to a real image of a BL Lac object is shown and discussed. Our results indicate that our cross-entropy model-fitting technique must be used in situations involving the analysis of complex emission regions having more than three sources, even though it is substantially slower than current model-fitting tasks (at least 10,000 times slower for a single processor, depending on the number of sources to be optimized). As in the case of any model fitting