Design of a fiber-optic multiphoton microscopy handheld probe

PubMed Central

Zhao, Yuan; Sheng, Mingyu; Huang, Lin; Tang, Shuo

2016-01-01

We have developed a fiber-optic multiphoton microscopy (MPM) system with handheld probe using femtosecond fiber laser. Here we present the detailed optical design and analysis of the handheld probe. The optical systems using Lightpath 352140 and 352150 as objective lens were analyzed. A custom objective module that includes Lightpath 355392 and two customized corrective lenses was designed. Their performances were compared by wavefront error, field curvature, astigmatism, F-θ error, and tolerance in Zemax simulation. Tolerance analysis predicted the focal spot size to be 1.13, 1.19 and 0.83 µm, respectively. Lightpath 352140 and 352150 were implemented in experiment and the measured lateral resolution was 1.22 and 1.3 µm, respectively, which matched with the prediction. MPM imaging by the handheld probe were conducted on leaf, fish scale and rat tail tendon. The MPM resolution can potentially be improved by the custom objective module. PMID:27699109

Design of a fiber-optic multiphoton microscopy handheld probe.

PubMed

Zhao, Yuan; Sheng, Mingyu; Huang, Lin; Tang, Shuo

2016-09-01

We have developed a fiber-optic multiphoton microscopy (MPM) system with handheld probe using femtosecond fiber laser. Here we present the detailed optical design and analysis of the handheld probe. The optical systems using Lightpath 352140 and 352150 as objective lens were analyzed. A custom objective module that includes Lightpath 355392 and two customized corrective lenses was designed. Their performances were compared by wavefront error, field curvature, astigmatism, F-θ error, and tolerance in Zemax simulation. Tolerance analysis predicted the focal spot size to be 1.13, 1.19 and 0.83 µm, respectively. Lightpath 352140 and 352150 were implemented in experiment and the measured lateral resolution was 1.22 and 1.3 µm, respectively, which matched with the prediction. MPM imaging by the handheld probe were conducted on leaf, fish scale and rat tail tendon. The MPM resolution can potentially be improved by the custom objective module.

Handheld Devices: Toward a More Mobile Campus.

ERIC Educational Resources Information Center

Fallon, Mary A. C.

2002-01-01

Offers an overview of the acceptance and use of handheld personal computing devices on campus that connect wirelessly to the campus network. Considers access; present and future software applications; uses in medial education; faculty training needs; and wireless technology issues. (Author/LRW)

Video Browsing on Handheld Devices

NASA Astrophysics Data System (ADS)

Hürst, Wolfgang

Recent improvements in processing power, storage space, and video codec development enable users now to playback video on their handheld devices in a reasonable quality. However, given the form factor restrictions of such a mobile device, screen size still remains a natural limit and - as the term "handheld" implies - always will be a critical resource. This is not only true for video but any data that is processed on such devices. For this reason, developers have come up with new and innovative ways to deal with large documents in such limited scenarios. For example, if you look at the iPhone, innovative techniques such as flicking have been introduced to skim large lists of text (e.g. hundreds of entries in your music collection). Automatically adapting the zoom level to, for example, the width of table cells when double tapping on the screen enables reasonable browsing of web pages that have originally been designed for large, desktop PC sized screens. A multi touch interface allows you to easily zoom in and out of large text documents and images using two fingers. In the next section, we will illustrate that advanced techniques to browse large video files have been developed in the past years, as well. However, if you look at state-of-the-art video players on mobile devices, normally just simple, VCR like controls are supported (at least at the time of this writing) that only allow users to just start, stop, and pause video playback. If supported at all, browsing and navigation functionality is often restricted to simple skipping of chapters via two single buttons for backward and forward navigation and a small and thus not very sensitive timeline slider.

An Investigation of Game-Embedded Handheld Devices to Enhance English Learning

ERIC Educational Resources Information Center

Hung, Hui-Chun; Young, Shelley Shwu-Ching

2015-01-01

This study proposed and implemented a system combining the advantages of both educational games and wireless handheld technology to promote the interactive English learning in the classroom setting. An interactive English vocabulary acquisition board game was designed with the system being implemented on handheld devices. Thirty sixth-grade…

Ultra-compact switchable SLO/OCT handheld probe design

NASA Astrophysics Data System (ADS)

LaRocca, Francesco; Nankivil, Derek; DuBose, Theodore; Farsiu, Sina; Izatt, Joseph A.

2015-03-01

Handheld scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) systems facilitate imaging of young children and subjects that have difficulty fixating. More compact and lightweight probes allow for better portability and increased comfort for the operator of the handheld probe. We describe a very compact, novel SLO and OCT handheld probe design. A single 2D microelectromechanical systems (MEMS) scanner and a custom optical design using a converging beam prior to the scanner permitted significant reduction in the system size. Our design utilized a combination of commercial and custom optics that were optimized in Zemax to achieve near diffraction-limited resolution of 8 μm over a 7° field of view. The handheld probe has a form factor of 7 x 6 x 2.5 cm and a weight of only 94 g, which is over an order of magnitude lighter than prior SLO-OCT handheld probes. Images were acquired from a normal subject with an incident power on the eye under the ANSI limit. With this device, which is the world's lightest and smallest SLO-OCT system, we were able to visualize parafoveal cone photoreceptors and nerve fiber bundles without the use of adaptive optics.

Epilepsy Forewarning Using A Hand-Held Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hively, LM

2005-02-21

Over the last decade, ORNL has developed and patented a novel approach for forewarning of a large variety of machine and biomedical events. The present implementation uses desktop computers to analyze archival data. This report describes the next logical step in this effort, namely use of a hand-held device for the analysis.

Correcting for motion artifact in handheld laser speckle images.

PubMed

Lertsakdadet, Ben; Yang, Bruce Y; Dunn, Cody E; Ponticorvo, Adrien; Crouzet, Christian; Bernal, Nicole; Durkin, Anthony J; Choi, Bernard

2018-03-01

Laser speckle imaging (LSI) is a wide-field optical technique that enables superficial blood flow quantification. LSI is normally performed in a mounted configuration to decrease the likelihood of motion artifact. However, mounted LSI systems are cumbersome and difficult to transport quickly in a clinical setting for which portability is essential in providing bedside patient care. To address this issue, we created a handheld LSI device using scientific grade components. To account for motion artifact of the LSI device used in a handheld setup, we incorporated a fiducial marker (FM) into our imaging protocol and determined the difference between highest and lowest speckle contrast values for the FM within each data set (Kbest and Kworst). The difference between Kbest and Kworst in mounted and handheld setups was 8% and 52%, respectively, thereby reinforcing the need for motion artifact quantification. When using a threshold FM speckle contrast value (KFM) to identify a subset of images with an acceptable level of motion artifact, mounted and handheld LSI measurements of speckle contrast of a flow region (KFLOW) in in vitro flow phantom experiments differed by 8%. Without the use of the FM, mounted and handheld KFLOW values differed by 20%. To further validate our handheld LSI device, we compared mounted and handheld data from an in vivo porcine burn model of superficial and full thickness burns. The speckle contrast within the burn region (KBURN) of the mounted and handheld LSI data differed by <4  %   when accounting for motion artifact using the FM, which is less than the speckle contrast difference between superficial and full thickness burns. Collectively, our results suggest the potential of handheld LSI with an FM as a suitable alternative to mounted LSI, especially in challenging clinical settings with space limitations such as the intensive care unit. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Handheld portable real-time tracking and communications device

DOEpatents

Wiseman, James M [Albuquerque, NM; Riblett, Jr., Loren E.; Green, Karl L [Albuquerque, NM; Hunter, John A [Albuquerque, NM; Cook, III, Robert N.; Stevens, James R [Arlington, VA

2012-05-22

Portable handheld real-time tracking and communications devices include; a controller module, communications module including global positioning and mesh network radio module, data transfer and storage module, and a user interface module enclosed in a water-resistant enclosure. Real-time tracking and communications devices can be used by protective force, security and first responder personnel to provide situational awareness allowing for enhance coordination and effectiveness in rapid response situations. Such devices communicate to other authorized devices via mobile ad-hoc wireless networks, and do not require fixed infrastructure for their operation.

A wireless handheld probe with spectrally constrained evolution strategies for diffuse optical imaging of tissue

NASA Astrophysics Data System (ADS)

Flexman, M. L.; Kim, H. K.; Stoll, R.; Khalil, M. A.; Fong, C. J.; Hielscher, A. H.

2012-03-01

We present a low-cost, portable, wireless diffuse optical imaging device. The handheld device is fast, portable, and can be applied to a wide range of both static and dynamic imaging applications including breast cancer, functional brain imaging, and peripheral artery disease. The continuous-wave probe has four near-infrared wavelengths and uses digital detection techniques to perform measurements at 2.3 Hz. Using a multispectral evolution algorithm for chromophore reconstruction, we can measure absolute oxygenated and deoxygenated hemoglobin concentration as well as scattering in tissue. Performance of the device is demonstrated using a series of liquid phantoms comprised of Intralipid®, ink, and dye.

75 FR 10502 - In the Matter of Certain Electronic Devices, Including Handheld Wireless Communications Devices...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-667; Investigation No. 337-TA-673] In the Matter of Certain Electronic Devices, Including Handheld Wireless Communications Devices; Notice of... Entirety AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that...

Hand-held optical imager (Gen-2): improved instrumentation and target detectability

PubMed Central

Gonzalez, Jean; DeCerce, Joseph; Erickson, Sarah J.; Martinez, Sergio L.; Nunez, Annie; Roman, Manuela; Traub, Barbara; Flores, Cecilia A.; Roberts, Seigbeh M.; Hernandez, Estrella; Aguirre, Wenceslao; Kiszonas, Richard

2012-01-01

Abstract. Hand-held optical imagers are developed by various researchers towards reflectance-based spectroscopic imaging of breast cancer. Recently, a Gen-1 handheld optical imager was developed with capabilities to perform two-dimensional (2-D) spectroscopic as well as three-dimensional (3-D) tomographic imaging studies. However, the imager was bulky with poor surface contact (∼30%) along curved tissues, and limited sensitivity to detect targets consistently. Herein, a Gen-2 hand-held optical imager that overcame the above limitations of the Gen-1 imager has been developed and the instrumentation described. The Gen-2 hand-held imager is less bulky, portable, and has improved surface contact (∼86%) on curved tissues. Additionally, the forked probe head design is capable of simultaneous bilateral reflectance imaging of both breast tissues, and also transillumination imaging of a single breast tissue. Experimental studies were performed on tissue phantoms to demonstrate the improved sensitivity in detecting targets using the Gen-2 imager. The improved instrumentation of the Gen-2 imager allowed detection of targets independent of their location with respect to the illumination points, unlike in Gen-1 imager. The developed imager has potential for future clinical breast imaging with enhanced sensitivity, via both reflectance and transillumination imaging. PMID:23224163

Design of a handheld optical coherence microscopy endoscope

NASA Astrophysics Data System (ADS)

Korde, Vrushali R.; Liebmann, Erica; Barton, Jennifer K.

2011-06-01

Optical coherence microscopy (OCM) combines coherence gating, high numerical aperture optics, and a fiber-core pinhole to provide high axial and lateral resolution with relatively large depth of imaging. We present a handheld rigid OCM endoscope designed for small animal surgical imaging, with a 6-mm diam tip, 1-mm scan width, and 1-mm imaging depth. X-Y scanning is performed distally with mirrors mounted to micro galvonometer scanners incorporated into the endoscope handle. The endoscope optical design consists of scanning doublets, an afocal Hopkins relay lens system, a 0.4 numerical aperture water immersion objective, and a cover glass. This endoscope can resolve laterally a 1.4-μm line pair feature and has an axial resolution (full width half maximum) of 5.4 μm. Images taken with this endoscope of fresh ex-vivo mouse ovaries show structural features, such as corpus luteum, primary follicles, growing follicles, and fallopian tubes. This rigid handheld OCM endoscope can be useful for a variety of minimally invasive and surgical imaging applications.

Programming Wireless Handheld Devices for Applications in Teaching Astronomy

NASA Astrophysics Data System (ADS)

Budiardja, R.; Saranathan, V.; Guidry, M.

2002-12-01

Wireless technology implemented with handheld devices has attractive features because of the potential to access large amounts of data and the prospect of on-the-fly computational analysis from a device that can be carried in a shirt pocket. We shall describe applications of such technology to the general paradigm of making digital wireless connections from the field to upload information and queries to network servers, executing (potentially complex) data analysis and/or database operations on fast network computers, and returning real-time information from this analysis to the handheld device in the field. As illustration, we shall describe several client/server programs that we have written for applications in teaching introductory astronomy. For example, one program allows static and dynamic properties of astronomical objects to be accessed in a remote observation laboratory setting using a digital cell phone or PDA. Another implements interactive quizzing over a cell phone or PDA using a 700-question introductory astronomy quiz database, thus permitting students to study for astronomy quizzes in any environment in which they have a few free minutes and a digital cell phone or wireless PDA. The presentation will include hands-on demonstrations with real devices.

78 FR 27441 - NIJ Evaluation of Hand-Held Cell Phone Detector Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-10

... Hand-Held Cell Phone Detector Devices AGENCY: National Institute of Justice, Department of Justice...-held cell phone detector devices for participation in an evaluation by the NIJ Corrections Technology...-held cell phone detector devices for participation in an evaluation by the NIJ Corrections Technology...

Performance of a new hand-held device for exhaled nitric oxide measurement in adults and children

PubMed Central

Alving, K; Janson, C; Nordvall, L

2006-01-01

Background Exhaled nitric oxide (NO) measurement has been shown to be a valuable tool in the management of patients with asthma. Up to now, most measurements have been done with stationary, chemiluminescence-based NO analysers, which are not suitable for the primary health care setting. A hand-held NO analyser which simplifies the measurement would be of value both in specialized and primary health care. In this study, the performance of a new electrochemical hand-held device for exhaled NO measurements (NIOX MINO) was compared with a standard stationary chemiluminescence unit (NIOX). Methods A total of 71 subjects (6–60 years; 36 males), both healthy controls and atopic patients with and without asthma were included. The mean of three approved exhalations (50 ml/s) in each device, and the first approved measurement in the hand-held device, were compared with regard to NO readings (Bland-Altman plots), measurement feasibility (success rate with 6 attempts) and repeatability (intrasubject SD). Results Success rate was high (≥ 84%) in both devices for both adults and children. The subjects represented a FENO range of 8–147 parts per billion (ppb). When comparing the mean of three measurements (n = 61), the median of the intrasubject difference in exhaled NO for the two devices was -1.2 ppb; thus generally the hand-held device gave slightly higher readings. The Bland-Altman plot shows that the 95% limits of agreement were -9.8 and 8.0 ppb. The intrasubject median difference between the NIOX and the first approved measurement in the NIOX MINO was -2.0 ppb, and limits of agreement were -13.2 and 10.2 ppb. The median repeatability for NIOX and NIOX MINO were 1.1 and 1.2 ppb, respectively. Conclusion The hand-held device (NIOX MINO) and the stationary system (NIOX) are in clinically acceptable agreement both when the mean of three measurements and the first approved measurement (NIOX MINO) is used. The hand-held device shows good repeatability, and it can be used

Performance of a new hand-held device for exhaled nitric oxide measurement in adults and children.

PubMed

Alving, K; Janson, C; Nordvall, L

2006-04-20

Exhaled nitric oxide (NO) measurement has been shown to be a valuable tool in the management of patients with asthma. Up to now, most measurements have been done with stationary, chemiluminescence-based NO analysers, which are not suitable for the primary health care setting. A hand-held NO analyser which simplifies the measurement would be of value both in specialized and primary health care. In this study, the performance of a new electrochemical hand-held device for exhaled NO measurements (NIOX MINO) was compared with a standard stationary chemiluminescence unit (NIOX). A total of 71 subjects (6-60 years; 36 males), both healthy controls and atopic patients with and without asthma were included. The mean of three approved exhalations (50 ml/s) in each device, and the first approved measurement in the hand-held device, were compared with regard to NO readings (Bland-Altman plots), measurement feasibility (success rate with 6 attempts) and repeatability (intrasubject SD). Success rate was high (> or = 84%) in both devices for both adults and children. The subjects represented a FENO range of 8-147 parts per billion (ppb). When comparing the mean of three measurements (n = 61), the median of the intrasubject difference in exhaled NO for the two devices was -1.2 ppb; thus generally the hand-held device gave slightly higher readings. The Bland-Altman plot shows that the 95% limits of agreement were -9.8 and 8.0 ppb. The intrasubject median difference between the NIOX and the first approved measurement in the NIOX MINO was -2.0 ppb, and limits of agreement were -13.2 and 10.2 ppb. The median repeatability for NIOX and NIOX MINO were 1.1 and 1.2 ppb, respectively. The hand-held device (NIOX MINO) and the stationary system (NIOX) are in clinically acceptable agreement both when the mean of three measurements and the first approved measurement (NIOX MINO) is used. The hand-held device shows good repeatability, and it can be used successfully on adults and most children

Neurosurgical hand-held optical coherence tomography (OCT) forward-viewing probe

NASA Astrophysics Data System (ADS)

Sun, Cuiru; Lee, Kenneth K. C.; Vuong, Barry; Cusimano, Michael; Brukson, Alexander; Mariampillai, Adrian; Standish, Beau A.; Yang, Victor X. D.

2012-02-01

A prototype neurosurgical hand-held optical coherence tomography (OCT) imaging probe has been developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic hand-held probe has been designed based on our group's previous work on electrostatically driven optical fibers. It has been packaged into a catheter probe in the familiar form factor of the clinically accepted Bayonet shaped neurosurgical non-imaging Doppler ultrasound probes. The optical design was optimized using ZEMAX simulation. Optical properties of the probe were tested to yield an ~20 um spot size, 5 mm working distance and a 3.5 mm field of view. The scan frequency can be increased or decreased by changing the applied voltage. Typically a scan frequency of less than 60Hz is chosen to keep the applied voltage to less than 2000V. The axial resolution of the probe was ~15 um (in air) as determined by the OCT system. A custom-triggering methodology has been developed to provide continuous stable imaging, which is crucial for clinical utility. Feasibility of this probe, in combination with a 1310 nm swept source OCT system was tested and images are presented to highlight the usefulness of such a forward viewing handheld OCT imaging probe. Knowledge gained from this research will lay the foundation for developing new OCT technologies for endovascular management of cerebral aneurysms and transsphenoidal neuroendoscopic treatment of pituitary tumors.

An Empirical Study on Operator Interface Design for Handheld Devices to Control Micro Aerial Vehicles

DTIC Science & Technology

2010-10-01

An Empirical Study on Operator Interface Design for Handheld Devices to Control Micro Aerial Vehicles Ming Hou...Report DRDC Toronto TR 2010-075 October 2010 An Empirical Study on Operator Interface Design for Handheld Devices to...drives the need for a small and light controller which will not hinder a soldier carrying it. This requirement brings an issue of designing an

Application of handheld devices to field research among underserved construction worker populations: a workplace health assessment pilot study.

PubMed

Caban-Martinez, Alberto J; Clarke, Tainya C; Davila, Evelyn P; Fleming, Lora E; Lee, David J

2011-04-01

Novel low-cost approaches for conducting rapid health assessments and health promotion interventions among underserved worker groups are needed. Recruitment and participation of construction workers is particularly challenging due to their often transient periods of work at any one construction site, and their limited time during work to participate in such studies. In the present methodology report, we discuss the experience, advantages and disadvantages of using touch screen handheld devices for the collection of field data from a largely underserved worker population. In March 2010, a workplace-centered pilot study to examine the feasibility of using a handheld personal device for the rapid health assessment of construction workers in two South Florida Construction sites was undertaken. A 45-item survey instrument, including health-related questions on tobacco exposure, workplace safety practices, musculoskeletal disorders and health symptoms, was programmed onto Apple iPod Touch® devices. Language sensitive (English and Spanish) recruitment scripts, verbal consent forms, and survey questions were all preloaded onto the handheld devices. The experience (time to survey administration and capital cost) of the handheld administration method was recorded and compared to approaches available in the extant literature. Construction workers were very receptive to the recruitment, interview and assessment processes conducted through the handheld devices. Some workers even welcomed the opportunity to complete the questionnaire themselves using the touch screen handheld device. A list of advantages and disadvantages emerged from this experience that may be useful in the rapid health assessment of underserved populations working in a variety of environmental and occupational health settings. Handheld devices, which are relatively inexpensive, minimize survey response error, and allow for easy storage of data. These technological research modalities are useful in the

77 FR 32996 - Certain Handheld Electronic Computing Devices, Related Software, and Components Thereof...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-04

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-769] Certain Handheld Electronic Computing Devices, Related Software, and Components Thereof; Termination of the Investigation Based on... electronic computing devices, related software, and components thereof by reason of infringement of certain...

Correcting for motion artifact in handheld laser speckle images

NASA Astrophysics Data System (ADS)

Lertsakdadet, Ben; Yang, Bruce Y.; Dunn, Cody E.; Ponticorvo, Adrien; Crouzet, Christian; Bernal, Nicole; Durkin, Anthony J.; Choi, Bernard

2018-03-01

Laser speckle imaging (LSI) is a wide-field optical technique that enables superficial blood flow quantification. LSI is normally performed in a mounted configuration to decrease the likelihood of motion artifact. However, mounted LSI systems are cumbersome and difficult to transport quickly in a clinical setting for which portability is essential in providing bedside patient care. To address this issue, we created a handheld LSI device using scientific grade components. To account for motion artifact of the LSI device used in a handheld setup, we incorporated a fiducial marker (FM) into our imaging protocol and determined the difference between highest and lowest speckle contrast values for the FM within each data set (Kbest and Kworst). The difference between Kbest and Kworst in mounted and handheld setups was 8% and 52%, respectively, thereby reinforcing the need for motion artifact quantification. When using a threshold FM speckle contrast value (KFM) to identify a subset of images with an acceptable level of motion artifact, mounted and handheld LSI measurements of speckle contrast of a flow region (KFLOW) in in vitro flow phantom experiments differed by 8%. Without the use of the FM, mounted and handheld KFLOW values differed by 20%. To further validate our handheld LSI device, we compared mounted and handheld data from an in vivo porcine burn model of superficial and full thickness burns. The speckle contrast within the burn region (KBURN) of the mounted and handheld LSI data differed by <4 % when accounting for motion artifact using the FM, which is less than the speckle contrast difference between superficial and full thickness burns. Collectively, our results suggest the potential of handheld LSI with an FM as a suitable alternative to mounted LSI, especially in challenging clinical settings with space limitations such as the intensive care unit.

SkinScan©: A PORTABLE LIBRARY FOR MELANOMA DETECTION ON HANDHELD DEVICES

PubMed Central

Wadhawan, Tarun; Situ, Ning; Lancaster, Keith; Yuan, Xiaojing; Zouridakis, George

2011-01-01

We have developed a portable library for automated detection of melanoma termed SkinScan© that can be used on smartphones and other handheld devices. Compared to desktop computers, embedded processors have limited processing speed, memory, and power, but they have the advantage of portability and low cost. In this study we explored the feasibility of running a sophisticated application for automated skin cancer detection on an Apple iPhone 4. Our results demonstrate that the proposed library with the advanced image processing and analysis algorithms has excellent performance on handheld and desktop computers. Therefore, deployment of smartphones as screening devices for skin cancer and other skin diseases can have a significant impact on health care delivery in underserved and remote areas. PMID:21892382

[Development of ophthalmologic software for handheld devices].

PubMed

Grottone, Gustavo Teixeira; Pisa, Ivan Torres; Grottone, João Carlos; Debs, Fernando; Schor, Paulo

2006-01-01

The formulas for calculation of intraocular lenses have evolved since the first theoretical formulas by Fyodorov. Among the second generation formulas, the SRK-I formula has a simple calculation, taking into account a calculation that only involved anteroposterior length, IOL constant and average keratometry. With the evolution of those formulas, complexicity increased making the reconfiguration of parameters in special situations impracticable. In this way the production and development of software for such a purpose, can help surgeons to recalculate those values if needed. To idealize, develop and test a Brazilian software for calculation of IOL dioptric power for handheld computers. For the development and programming of software for calculation of IOL, we used PocketC program (OrbWorks Concentrated Software, USA). We compared the results collected from a gold-standard device (Ultrascan/Alcon Labs) with the simulation of 100 fictitious patients, using the same IOL parameters. The results were grouped for ULTRASCAN data and SOFTWARE data. Using SRK/T formula the range of those parameters included a keratometry varying between 35 and 55D, axial length between 20 and 28 mm, IOL constants of 118.7, 118.3 and 115.8. Using Wilcoxon test, it was shown that the groups do not differ (p=0.314). We had a variation in the Ultrascan sample between 11.82 and 27.97. In the tested program sample the variation was practically similar (11.83-27.98). The average of the Ultrascan group was 20.93. The software group had a similar average. The standard deviation of the samples was also similar (4.53). The precision of IOL software for handheld devices was similar to that of the standard devices using the SRK/T formula. The software worked properly, was steady without bugs in tested models of operational system.

Online Responses towards Parental Rearing Styles Regarding Hand-Held Devices

ERIC Educational Resources Information Center

Geng, Gretchen; Disney, Leigh

2014-01-01

This article reviewed the literature on parental rearing styles and used responses from an online discussion forum to investigate people's opinions towards parental rearing styles and strategies when children use hand-held devices. Critical discourse analysis (CDA) was used as an analysis method via micro, meso and macro multi-level…

Handheld juggernaut.

PubMed

Hagland, Mark

2010-08-01

Not only are hospital, health system, and medical group ClOs and clinical informaticists deploying handheld mobile devices across their enterprises as clinical computing tools; clinicians, especially physicians, are increasingly bringing their own BlackBerrys, iPhones, iPads, Android devices, and other handhelds, into patient care organizations for their personal clinical use. Not surprisingly, the challenges--as well as the opportunities--are multilayered and complex, and include the strategic planning, infrastructure, clinician preference, clinician workflow, and security issues involved in the emerging mobile handheld revolution. The diversity of approaches among ClOs and other healthcare IT leaders on such issues is striking, and underscores the need for flexibility and nimbleness going forward.

Hand-Held Devices Detect Explosives and Chemical Agents

NASA Technical Reports Server (NTRS)

2010-01-01

Ion Applications Inc., of West Palm Beach, Florida, partnered with Ames Research Center through Small Business Innovation Research (SBIR) agreements to develop a miniature version ion mobility spectrometer (IMS). While NASA was interested in the instrument for detecting chemicals during exploration of distant planets, moons, and comets, the company has incorporated the technology into a commercial hand-held IMS device for use by the military and other public safety organizations. Capable of detecting and identifying molecules with part-per-billion sensitivity, the technology now provides soldiers with portable explosives and chemical warfare agent detection. The device is also being adapted for detecting drugs and is employed in industrial processes such as semiconductor manufacturing.

A Data-Driven Design Evaluation Tool for Handheld Device Soft Keyboards

PubMed Central

Trudeau, Matthieu B.; Sunderland, Elsie M.; Jindrich, Devin L.; Dennerlein, Jack T.

2014-01-01

Thumb interaction is a primary technique used to operate small handheld devices such as smartphones. Despite the different techniques involved in operating a handheld device compared to a personal computer, the keyboard layouts for both devices are similar. A handheld device keyboard that considers the physical capabilities of the thumb may improve user experience. We developed and applied a design evaluation tool for different geometries of the QWERTY keyboard using a performance evaluation model. The model utilizes previously collected data on thumb motor performance and posture for different tap locations and thumb movement directions. We calculated a performance index (PITOT, 0 is worst and 2 is best) for 663 designs consisting in different combinations of three variables: the keyboard's radius of curvature (R) (mm), orientation (O) (°), and vertical location on the screen (L). The current standard keyboard performed poorly (PITOT = 0.28) compared to other designs considered. Keyboard location (L) contributed to the greatest variability in performance out of the three design variables, suggesting that designers should modify this variable first. Performance was greatest for designs in the middle keyboard location. In addition, having a slightly upward curve (R = −20 mm) and orientated perpendicular to the thumb's long axis (O = −20°) improved performance to PITOT = 1.97. Poorest performances were associated with placement of the keyboard's spacebar in the bottom right corner of the screen (e.g., the worst was for R = 20 mm, O = 40°, L =  Bottom (PITOT = 0.09)). While this evaluation tool can be used in the design process as an ergonomic reference to promote user motor performance, other design variables such as visual access and usability still remain unexplored. PMID:25211465

Development of a Handheld Line Information Reader and Generator for Efficient Management of Optical Communication Lines

PubMed Central

Lee, Jaeyul; Kwon, Hyungwoo; Song, Jaewon; Jeon, Mansik; Kim, Jeehyun

2017-01-01

A handheld line information reader and a line information generator were developed for the efficient management of optical communication lines. The line information reader consists of a photo diode, trans-impedance amplifier, voltage amplifier, microcontroller unit, display panel, and communication modules. The line information generator consists of a laser diode, laser driving circuits, microcontroller unit, and communication modules. The line information reader can detect the optical radiation field of the test line by bending the optical fiber. To enhance the sensitivity of the line information reader, an additional lens was used with a focal length of 4.51 mm. Moreover, the simulation results obtained through BeamPROP® software from Synopsys, Inc. demonstrated a stronger optical radiation field of the fiber due to a longer transmission wavelength and larger bending angle of the fiber. Therefore, the developed devices can be considered as useful tools for the efficient management of optical communication lines. PMID:28837058

Clinical translation of handheld optical coherence tomography: practical considerations and recent advancements

NASA Astrophysics Data System (ADS)

Monroy, Guillermo L.; Won, Jungeun; Spillman, Darold R.; Dsouza, Roshan; Boppart, Stephen A.

2017-12-01

Since the inception of optical coherence tomography (OCT), advancements in imaging system design and handheld probes have allowed for numerous advancements in disease diagnostics and characterization of the structural and optical properties of tissue. OCT system developers continue to reduce form factor and cost, while improving imaging performance (speed, resolution, etc.) and flexibility for applicability in a broad range of fields, and nearly every clinical specialty. An extensive array of components to construct customized systems has also become available, with a range of commercial entities that produce high-quality products, from single components to full systems, for clinical and research use. Many advancements in the development of these miniaturized and portable systems can be linked back to a specific challenge in academic research, or a clinical need in medicine or surgery. Handheld OCT systems are discussed and explored for various applications. Handheld systems are discussed in terms of their relative level of portability and form factor, with mention of the supporting technologies and surrounding ecosystem that bolstered their development. Additional insight from our efforts to implement systems in several clinical environments is provided. The trend toward well-designed, efficient, and compact handheld systems paves the way for more widespread adoption of OCT into point-of-care or point-of-procedure applications in both clinical and commercial settings.

Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

NASA Astrophysics Data System (ADS)

Oh, Mirae; Lee, Hoonsoo; Cho, Hyunjeong; Moon, Sang-Ho; Kim, Eun-Kyung; Kim, Moon S.

2016-05-01

Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by highlighting contaminated food and food contact surfaces on a display monitor. It can be used under ambient lighting conditions in food processing plants. Critical components of the imaging device includes four 405-nm 10-W LEDs for fluorescence excitation, a charge-coupled device (CCD) camera, optical filter (670 nm used for this study), and Wi-Fi transmitter for broadcasting real-time video/images to monitoring devices such as smartphone and tablet. This study aimed to investigate the effectiveness of HFID in enhancing visual detection of fecal contamination on red meat, fat, and bone surfaces of beef under varying ambient luminous intensities (0, 10, 30, 50 and 70 foot-candles). Overall, diluted feces on fat, red meat and bone areas of beef surfaces were detectable in the 670-nm single-band fluorescence images when using the HFID under 0 to 50 foot-candle ambient lighting.

Portable (handheld) clinical device for quantitative spectroscopy of skin, utilizing spatial frequency domain reflectance techniques

NASA Astrophysics Data System (ADS)

Saager, Rolf B.; Dang, An N.; Huang, Samantha S.; Kelly, Kristen M.; Durkin, Anthony J.

2017-09-01

Spatial Frequency Domain Spectroscopy (SFDS) is a technique for quantifying in-vivo tissue optical properties. SFDS employs structured light patterns that are projected onto tissues using a spatial light modulator, such as a digital micromirror device. In combination with appropriate models of light propagation, this technique can be used to quantify tissue optical properties (absorption, μa, and scattering, μs', coefficients) and chromophore concentrations. Here we present a handheld implementation of an SFDS device that employs line (one dimensional) imaging. This instrument can measure 1088 spatial locations that span a 3 cm line as opposed to our original benchtop SFDS system that only collects a single 1 mm diameter spot. This imager, however, retains the spectral resolution (˜1 nm) and range (450-1000 nm) of our original benchtop SFDS device. In the context of homogeneous turbid media, we demonstrate that this new system matches the spectral response of our original system to within 1% across a typical range of spatial frequencies (0-0.35 mm-1). With the new form factor, the device has tremendously improved mobility and portability, allowing for greater ease of use in a clinical setting. A smaller size also enables access to different tissue locations, which increases the flexibility of the device. The design of this portable system not only enables SFDS to be used in clinical settings but also enables visualization of properties of layered tissues such as skin.

Characterizing infantile hemangiomas with a near-infrared spectroscopic handheld wireless device

NASA Astrophysics Data System (ADS)

Fong, Christopher J.; Hoi, Jennifer W.; Kim, Hyun K.; Behr, Gerald; Geller, Lauren; Antonov, Nina; Flexman, Molly; Garzon, Maria; Hielscher, Andreas H.

2015-03-01

Infantile hemangiomas (IH) are common vascular growths that occur in 5-10% of neonates and have the potential to cause disfiguring and even life-threatening complications. Currently, no objective tool exist to monitor either progression or treatment of IH. To address this unmet clinical need, we have developed a handheld wireless device (HWD) that uses diffuse optical spectroscopy for the assessment of IH. The system employs 4 wavelengths (l=780nm, 805nm, 850nm, and 905nm) and 6 source-detector pairs with distances between 0.6 and 20 mm. Placed on the skin surface, backreflection data is obtained and a multispectral evolution algorithm is used to determine total hemoglobin concentration and tissue oxygen saturation. First results of an ongoing pilot study involving 13 patients (average enrollment age = 25 months) suggest that an increase in hypoxic stress over time can lead to the proliferation of IH. Involuting IH lesions showed an increase in tissue oxygen saturation as well as a decrease in total hemoglobin.

Handheld computing in pathology

PubMed Central

Park, Seung; Parwani, Anil; Satyanarayanan, Mahadev; Pantanowitz, Liron

2012-01-01

Handheld computing has had many applications in medicine, but relatively few in pathology. Most reported uses of handhelds in pathology have been limited to experimental endeavors in telemedicine or education. With recent advances in handheld hardware and software, along with concurrent advances in whole-slide imaging (WSI), new opportunities and challenges have presented themselves. This review addresses the current state of handheld hardware and software, provides a history of handheld devices in medicine focusing on pathology, and presents future use cases for such handhelds in pathology. PMID:22616027

Extensional rheometry with a handheld mobile device

NASA Astrophysics Data System (ADS)

Marshall, Kristin A.; Liedtke, Aleesha M.; Todt, Anika H.; Walker, Travis W.

2017-06-01

The on-site characterization of complex fluids is important for a number of academic and industrial applications. Consequently, a need exists to develop portable rheometers that can provide in the field diagnostics and serve as tools for rapid quality assurance. With the advancement of smartphone technology and the widespread global ownership of smart devices, mobile applications are attractive as platforms for rheological characterization. The present work investigates the use of a smartphone device for the extensional characterization of a series of Boger fluids composed of glycerol/water and poly(ethylene oxide), taking advantage of the increasing high-speed video capabilities (currently up to 240 Hz capture rate at 720p) of smartphone cameras. We report a noticeable difference in the characterization of samples with slight variations in polymer concentration and discuss current device limitations. Potential benefits of a handheld extensional rheometer include its use as a point-of-care diagnostic tool, especially in developing communities, as well as a simple and inexpensive tool for assessing product quality in industry.

Portable multiwavelength laser diode source for handheld photoacoustic devices

NASA Astrophysics Data System (ADS)

Canal, Celine; Laugustin, Arnaud; Kohl, Andreas; Rabot, Olivier

2016-04-01

The ageing population faces today an increase of chronic diseases such as rheumatism/arthritis, cancer and cardio vascular diseases for which appropriate treatments based on a diagnosis at an early-stage of the disease are required. Some imaging techniques are already available in order to get structural information. Within the non-invasive group, ultrasound images are common in these fields of medicine. However, there is a need for a point-of-care device for imaging smaller structures such as blood vessels that cannot be observed with purely ultrasound based devices. Photoacoustics proved to be an attractive candidate. This novel imaging technique combines pulsed laser light for excitation of tissues and an ultrasound transducer as a receptor. Introduction of this technique into the clinic requires to drastically shrink the size and cost of the expensive and bulky nanosecond lasers generally used for light emission. In that context, demonstration of ultra-short pulse emission with highly efficient laser diodes in the near-infrared range has been performed by Quantel, France. A multi-wavelength laser source as small as a hand emitted more than 1 mJ per wavelength with four different wavelengths available in pulses of about 90 ns. Such a laser source can be integrated into high sensitivity photoacoustic handheld systems due to their outstanding electrical-to-optical efficiency of about 25 %. Further work continues to decrease the pulse length as low as 40 ns while increasing the pulse energy to 2 mJ.

Correlation of Handheld Infrared Skin Thermometer and Infrared Videothermography Device for Measurement of Corneal Temperature.

PubMed

Oztas, Zafer; Barut Selver, Ozlem; Akkin, Cezmi; Canturk, Ecem; Afrashi, Filiz

2016-05-01

In our study, we aimed to investigate the correlation of handheld infrared skin thermometer and videothermography device for the measurement of corneal temperature. Forty healthy individuals (80 eyes) were enrolled to the study. Participants underwent a detailed ophthalmologic examination and medical history review for excluding any ocular and systemic diseases. The measurements of the central corneal temperature were performed in a room having constant temperature, humidity, and brightness levels. To avoid any variability, all the temperature measurements were performed in the same examination room by a single examiner. The temperature was measured with a handheld infrared skin thermometer (MEDISANA, FTN) from the corneal surface. The same instrument was also used to measure the subjects' body temperature. Moreover, the subjects underwent the corneal temperature measurement by a noncontact videothermography device (Optris PI 450; Optris GmbH). The male to female ratio was 19:21 among the subjects. The mean age was 25.1±4.7 years. The mean body temperature was 36.93±0.33°C. The mean corneal temperatures measured by the handheld infrared skin thermometer and the ocular videothermography device were 36.94±0.28°C and 35.61±0.61°C, respectively (P<0.01). The mean temperature difference was 1.34±0.57°C, with a 95% confidence interval. There was a moderate correlation between the corneal temperatures measured by the 2 devices in the right, the left eyes, and both eyes, respectively (P=0.450, 0.539, 0.490). Handheld infrared skin thermometers can be used for the evaluation of the corneal temperature. These devices may provide a simple, practical, and cheaper way to detect the corneal temperature, and the widely performed corneal temperature measurements may afford us to understand the temperature variability in numerous ocular conditions in a better way.

WebAlchemist: a Web transcoding system for mobile Web access in handheld devices

NASA Astrophysics Data System (ADS)

Whang, Yonghyun; Jung, Changwoo; Kim, Jihong; Chung, Sungkwon

2001-11-01

In this paper, we describe the design and implementation of WebAlchemist, a prototype web transcoding system, which automatically converts a given HTML page into a sequence of equivalent HTML pages that can be properly displayed on a hand-held device. The Web/Alchemist system is based on a set of HTML transcoding heuristics managed by the Transcoding Manager (TM) module. In order to tackle difficult-to-transcode pages such as ones with large or complex table structures, we have developed several new transcoding heuristics that extract partial semantics from syntactic information such as the table width, font size and cascading style sheet. Subjective evaluation results using popular HTML pages (such as the CNN home page) show that WebAlchemist generates readable, structure-preserving transcoded pages, which can be properly displayed on hand-held devices.

Hand-held spectrophotometer design for textile fabrics

NASA Astrophysics Data System (ADS)

Böcekçi, Veysel Gökhan; Yıldız, Kazım

2017-09-01

In this study, a hand-held spectrophotometer was designed by taking advantage of the developments in modern optoelectronic technology. Spectrophotometer devices are used to determine the color information from the optic properties of the materials. As an alternative to a desktop spectrophotometer device we have implemented, it is the first prototype, low cost and portable. The prototype model designed for the textile industry can detect the color tone of any fabric. The prototype model consists of optic sensor, processor, display floors. According to the color applied on the optic sensor, it produces special frequency information on its output at that color value. In Arduino type processor, the frequency information is evaluated by the program we have written and the color tone information between 0-255 ton is decided and displayed on the screen.

The Use of Handheld Devices for Improved Phonemic Awareness in a Traditional Kindergarten Classroom

ERIC Educational Resources Information Center

Magagna-McBee, Cristy Ann

2010-01-01

Effective teaching strategies that improve the development of phonemic awareness are important to ensure students are fluent readers by third grade. The use of handheld devices to improve phonemic awareness with kindergarten students may be such a strategy, but no research exists that evaluates the use of these devices. This study explored the…

Using a Handheld Device for Patient Data Collection: A Pilot for Medical Countermeasures Surveillance.

PubMed

Daley, Matthew F; Goddard, Kristin; McClung, Melissa; Davidson, Arthur; Weiss, Gretchen; Palen, Ted; Nyirenda, Carsie; Platt, Richard; Courtney, Brooke; Reichman, Marsha E

2016-01-01

Medical countermeasures (MCMs) are medical products used during public health emergencies. This study, conducted within the Mini-Sentinel Initiative, sought to develop the patient identification and matching processes necessary to assess safety outcomes for MCMs. A handheld device was used to collect identifying information (e.g., name, birthdate, and sex) from the driver's licenses of 421 individuals presenting for routine care at their primary care medical office. Overall, 374 individuals (88.8%) could be linked to their electronic health data using driver's license information. The device was also pilot-tested at a seasonal influenza immunization clinic: detailed vaccine information (e.g., lot number and manufacturer) was captured with a high degree of accuracy. This investigation demonstrated that a handheld device is a feasible means of collecting patient identity and medical product receipt data. This capacity should be useful for safety surveillance of MCMs, particularly when dispensed in settings outside the traditional health-care delivery system.

Identification of handheld objects for electro-optic/FLIR applications

NASA Astrophysics Data System (ADS)

Moyer, Steve K.; Flug, Eric; Edwards, Timothy C.; Krapels, Keith A.; Scarbrough, John

2004-08-01

This paper describes research on the determination of the fifty-percent probability of identification cycle criterion (N50) for two sets of handheld objects. The first set consists of 12 objects which are commonly held in a single hand. The second set consists of 10 objects commonly held in both hands. These sets consist of not only typical civilian handheld objects but also objects that are potentially lethal. A pistol, a cell phone, a rocket propelled grenade (RPG) launcher, and a broom are examples of the objects in these sets. The discrimination of these objects is an inherent part of homeland security, force protection, and also general population security. Objects were imaged from each set in the visible and mid-wave infrared (MWIR) spectrum. Various levels of blur are then applied to these images. These blurred images were then used in a forced choice perception experiment. Results were analyzed as a function of blur level and target size to give identification probability as a function of resolvable cycles on target. These results are applicable to handheld object target acquisition estimates for visible imaging systems and MWIR systems. This research provides guidance in the design and analysis of electro-optical systems and forward-looking infrared (FLIR) systems for use in homeland security, force protection, and also general population security.

Design and characterization of a handheld multimodal imaging device for the assessment of oral epithelial lesions

NASA Astrophysics Data System (ADS)

Higgins, Laura M.; Pierce, Mark C.

2014-08-01

A compact handpiece combining high resolution fluorescence (HRF) imaging with optical coherence tomography (OCT) was developed to provide real-time assessment of oral lesions. This multimodal imaging device simultaneously captures coregistered en face images with subcellular detail alongside cross-sectional images of tissue microstructure. The HRF imaging acquires a 712×594 μm2 field-of-view at the sample with a spatial resolution of 3.5 μm. The OCT images were acquired to a depth of 1.5 mm with axial and lateral resolutions of 9.3 and 8.0 μm, respectively. HRF and OCT images are simultaneously displayed at 25 fps. The handheld device was used to image a healthy volunteer, demonstrating the potential for in vivo assessment of the epithelial surface for dysplastic and neoplastic changes at the cellular level, while simultaneously evaluating submucosal involvement. We anticipate potential applications in real-time assessment of oral lesions for improved surveillance and surgical guidance.

Noninvasively Imaging Subcutaneous Tumor Xenograft by a Handheld Raman Detector, with the Assistance of an Optical Clearing Agent.

PubMed

Zhang, Yunfei; Liu, Haoran; Tang, Jiali; Li, Zhuoyun; Zhou, Xingyu; Zhang, Ren; Chen, Liang; Mao, Ying; Li, Cong

2017-05-31

A handheld Raman detector with operational convenience, high portability, and rapid acquisition rate has been applied in clinics for diagnostic purposes. However, the inherent weakness of Raman scattering and strong scattering of the turbid tissue restricts its utilization to superficial locations. To extend the applications of a handheld Raman detector to deep tissues, a gold nanostar-based surface-enhanced Raman scattering (SERS) nanoprobe with robust colloidal stability, a fingerprint-like spectrum, and extremely high sensitivity (5.0 fM) was developed. With the assistance of FPT, a multicomponent optical clearing agent (OCA) efficiently suppressing light scattering from the turbid dermal tissues, the handheld Raman detector noninvasively visualized the subcutaneous tumor xenograft with a high target-to-background ratio after intravenous injection of the gold nanostar-based SERS nanoprobe. To the best of our knowledge, this work is the first example to introduce the optical clearing technique in assisting SERS imaging in vivo. The combination of optical clearing technology and SERS is a promising strategy for the extension of the clinical applications of the handheld Raman detector from superficial tissues to subcutaneous or even deeper lesions that are usually "concealed" by the turbid dermal tissue.

An efficient solid modeling system based on a hand-held 3D laser scan device

NASA Astrophysics Data System (ADS)

Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

2014-12-01

The hand-held 3D laser scanner sold in the market is appealing for its port and convenient to use, but price is expensive. To develop such a system based cheap devices using the same principles as the commercial systems is impossible. In this paper, a simple hand-held 3D laser scanner is developed based on a volume reconstruction method using cheap devices. Unlike convenient laser scanner to collect point cloud of an object surface, the proposed method only scan few key profile curves on the surface. Planar section curve network can be generated from these profile curves to construct a volume model of the object. The details of design are presented, and illustrated by the example of a complex shaped object.

Hand-held medical robots.

PubMed

Payne, Christopher J; Yang, Guang-Zhong

2014-08-01

Medical robots have evolved from autonomous systems to tele-operated platforms and mechanically-grounded, cooperatively-controlled robots. Whilst these approaches have seen both commercial and clinical success, uptake of these robots remains moderate because of their high cost, large physical footprint and long setup times. More recently, researchers have moved toward developing hand-held robots that are completely ungrounded and manipulated by surgeons in free space, in a similar manner to how conventional instruments are handled. These devices provide specific functions that assist the surgeon in accomplishing tasks that are otherwise challenging with manual manipulation. Hand-held robots have the advantages of being compact and easily integrated into the normal surgical workflow since there is typically little or no setup time. Hand-held devices can also have a significantly reduced cost to healthcare providers as they do not necessitate the complex, multi degree-of-freedom linkages that grounded robots require. However, the development of such devices is faced with many technical challenges, including miniaturization, cost and sterility, control stability, inertial and gravity compensation and robust instrument tracking. This review presents the emerging technical trends in hand-held medical robots and future development opportunities for promoting their wider clinical uptake.

Gen-2 hand-held optical imager towards cancer imaging: reflectance and transillumination phantom studies.

PubMed

Gonzalez, Jean; Roman, Manuela; Hall, Michael; Godavarty, Anuradha

2012-01-01

Hand-held near-infrared (NIR) optical imagers are developed by various researchers towards non-invasive clinical breast imaging. Unlike these existing imagers that can perform only reflectance imaging, a generation-2 (Gen-2) hand-held optical imager has been recently developed to perform both reflectance and transillumination imaging. The unique forked design of the hand-held probe head(s) allows for reflectance imaging (as in ultrasound) and transillumination or compressed imaging (as in X-ray mammography). Phantom studies were performed to demonstrate two-dimensional (2D) target detection via reflectance and transillumination imaging at various target depths (1-5 cm deep) and using simultaneous multiple point illumination approach. It was observed that 0.45 cc targets were detected up to 5 cm deep during transillumination, but limited to 2.5 cm deep during reflectance imaging. Additionally, implementing appropriate data post-processing techniques along with a polynomial fitting approach, to plot 2D surface contours of the detected signal, yields distinct target detectability and localization. The ability of the gen-2 imager to perform both reflectance and transillumination imaging allows its direct comparison to ultrasound and X-ray mammography results, respectively, in future clinical breast imaging studies.

Concept for tremor compensation for a handheld OCT-laryngoscope

NASA Astrophysics Data System (ADS)

Donner, Sabine; Deutsch, Stefanie; Bleeker, Sebastian; Ripken, Tammo; Krüger, Alexander

2013-06-01

Optical coherence tomography (OCT) is a non-invasive imaging technique which can create optical tissue sections, enabling diagnosis of vocal cord tissue. To take full advantage from the non-contact imaging technique, OCT was adapted to an indirect laryngoscope to work on awake patients. Using OCT in a handheld diagnostic device the challenges of rapid working distance adjustment and tracking of axial motion arise. The optical focus of the endoscopic sample arm and the reference-arm length can be adjusted in a range of 40 mm to 90 mm. Automatic working distance adjustment is based on image analysis of OCT B-scans which identifies off depth images as well as position errors. The movable focal plane and reference plane are used to adjust working distance to match the sample depth and stabilise the sample in the desired axial position of the OCT scans. The autofocus adjusts the working distance within maximum 2.7 seconds for the maximum initial displacement of 40 mm. The amplitude of hand tremor during 60 s handheld scanning was reduced to 50 % and it was shown that the image stabilisation keeps the position error below 0.5 mm. Fast automatic working distance adjustment is crucial to minimise the duration of the diagnostic procedure. The image stabilisation compensates relative axial movements during handheld scanning.

Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

USDA-ARS?s Scientific Manuscript database

Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by ...

The sounds of handheld audio players.

PubMed

Rudy, Susan F

2007-01-01

Hearing experts and public health organizations have longstanding hearing safety concerns about personal handheld audio devices, which are growing in both number and popularity. This paper reviews the maximum sound levels of handheld compact disc players, MP3 players, and an iPod. It further reviews device factors that influence the sound levels produced by these audio devices and ways to reduce the risk to hearing during their use.

Handheld computers in critical care.

PubMed

Lapinsky, S E; Weshler, J; Mehta, S; Varkul, M; Hallett, D; Stewart, T E

2001-08-01

Computing technology has the potential to improve health care management but is often underutilized. Handheld computers are versatile and relatively inexpensive, bringing the benefits of computers to the bedside. We evaluated the role of this technology for managing patient data and accessing medical reference information, in an academic intensive-care unit (ICU). Palm III series handheld devices were given to the ICU team, each installed with medical reference information, schedules, and contact numbers. Users underwent a 1-hour training session introducing the hardware and software. Various patient data management applications were assessed during the study period. Qualitative assessment of the benefits, drawbacks, and suggestions was performed by an independent company, using focus groups. An objective comparison between a paper and electronic handheld textbook was achieved using clinical scenario tests. During the 6-month study period, the 20 physicians and 6 paramedical staff who used the handheld devices found them convenient and functional but suggested more comprehensive training and improved search facilities. Comparison of the handheld computer with the conventional paper text revealed equivalence. Access to computerized patient information improved communication, particularly with regard to long-stay patients, but changes to the software and the process were suggested. The introduction of this technology was well received despite differences in users' familiarity with the devices. Handheld computers have potential in the ICU, but systems need to be developed specifically for the critical-care environment.

Handheld computers in critical care

PubMed Central

Lapinsky, Stephen E; Weshler, Jason; Mehta, Sangeeta; Varkul, Mark; Hallett, Dave; Stewart, Thomas E

2001-01-01

Background Computing technology has the potential to improve health care management but is often underutilized. Handheld computers are versatile and relatively inexpensive, bringing the benefits of computers to the bedside. We evaluated the role of this technology for managing patient data and accessing medical reference information, in an academic intensive-care unit (ICU). Methods Palm III series handheld devices were given to the ICU team, each installed with medical reference information, schedules, and contact numbers. Users underwent a 1-hour training session introducing the hardware and software. Various patient data management applications were assessed during the study period. Qualitative assessment of the benefits, drawbacks, and suggestions was performed by an independent company, using focus groups. An objective comparison between a paper and electronic handheld textbook was achieved using clinical scenario tests. Results During the 6-month study period, the 20 physicians and 6 paramedical staff who used the handheld devices found them convenient and functional but suggested more comprehensive training and improved search facilities. Comparison of the handheld computer with the conventional paper text revealed equivalence. Access to computerized patient information improved communication, particularly with regard to long-stay patients, but changes to the software and the process were suggested. Conclusions The introduction of this technology was well received despite differences in users' familiarity with the devices. Handheld computers have potential in the ICU, but systems need to be developed specifically for the critical-care environment. PMID:11511337

Learning Motivation and Adaptive Video Caption Filtering for EFL Learners Using Handheld Devices

ERIC Educational Resources Information Center

Hsu, Ching-Kun

2015-01-01

The aim of this study was to provide adaptive assistance to improve the listening comprehension of eleventh grade students. This study developed a video-based language learning system for handheld devices, using three levels of caption filtering adapted to student needs. Elementary level captioning excluded 220 English sight words (see Section 1…

Rich internet application system for patient-centric healthcare data management using handheld devices.

PubMed

Constantinescu, L; Pradana, R; Kim, J; Gong, P; Fulham, Michael; Feng, D

2009-01-01

Rich Internet Applications (RIAs) are an emerging software platform that blurs the line between web service and native application, and is a powerful tool for handheld device deployment. By democratizing health data management and widening its availability, this software platform has the potential to revolutionize telemedicine, clinical practice, medical education and information distribution, particularly in rural areas, and to make patient-centric medical computing a reality. In this paper, we propose a telemedicine application that leverages the ability of a mobile RIA platform to transcode, organise and present textual and multimedia data, which are sourced from medical database software. We adopted a web-based approach to communicate, in real-time, with an established hospital information system via a custom RIA. The proposed solution allows communication between handheld devices and a hospital information system for media streaming with support for real-time encryption, on any RIA enabled platform. We demonstrate our prototype's ability to securely and rapidly access, without installation requirements, medical data ranging from simple textual records to multi-slice PET-CT images and maximum intensity (MIP) projections.

Performance of handheld electrocardiogram devices to detect atrial fibrillation in a cardiology and geriatric ward setting.

PubMed

Desteghe, Lien; Raymaekers, Zina; Lutin, Mark; Vijgen, Johan; Dilling-Boer, Dagmara; Koopman, Pieter; Schurmans, Joris; Vanduynhoven, Philippe; Dendale, Paul; Heidbuchel, Hein

2017-01-01

To determine the usability, accuracy, and cost-effectiveness of two handheld single-lead electrocardiogram (ECG) devices for atrial fibrillation (AF) screening in a hospital population with an increased risk for AF. Hospitalized patients (n = 445) at cardiological or geriatric wards were screened for AF by two handheld ECG devices (MyDiagnostick and AliveCor). The performance of the automated algorithm of each device was evaluated against a full 12-lead or 6-lead ECG recording. All ECGs and monitor tracings were also independently reviewed in a blinded fashion by two electrophysiologists. Time investments by nurses and physicians were tracked and used to estimate cost-effectiveness of different screening strategies. Handheld recordings were not possible in 7 and 21.4% of cardiology and geriatric patients, respectively, because they were not able to hold the devices properly. Even after the exclusion of patients with an implanted device, sensitivity and specificity of the automated algorithms were suboptimal (Cardiology: 81.8 and 94.2%, respectively, for MyDiagnostick; 54.5 and 97.5%, respectively, for AliveCor; Geriatrics: 89.5 and 95.7%, respectively, for MyDiagnostick; 78.9 and 97.9%, respectively, for AliveCor). A scenario based on automated AliveCor evaluation in patients without AF history and without an implanted device proved to be the most cost-effective method, with a provider cost to identify one new AF patient of €193 and €82 at cardiology and geriatrics, respectively. The cost to detect one preventable stroke per year would be €7535 and €1916, respectively (based on average CHA 2 DS 2 -VASc of 3.9 ± 2.0 and 5.0 ± 1.5, respectively). Manual interpretation increases sensitivity, but decreases specificity, doubling the cost per detected patient, but remains cheaper than sole 12-lead ECG screening. Using AliveCor or MyDiagnostick handheld recorders requires a structured screening strategy to be effective and cost-effective in a hospital setting

Evaluation of a handheld device for measurement of β-hydroxybutyrate concentration to identify prepartum dairy cattle at risk of developing postpartum hyperketonemia.

PubMed

Tatone, Elise H; Gordon, Jessica L; LeBlanc, Stephen J; Duffield, Todd F

2015-05-15

To evaluate the use of a handheld device for measurement of β-hydroxybutyrate (BHBA) concentration to identify prepartum dairy cattle at risk of developing hyperketonemia during the first week after parturition. Cross-sectional study. Animals-210 prepartum dairy cows from 6 herds. A blood sample was collected from each cow 3 to 9 days before its expected calving date. β-Hydroxybutyrate concentration was immediately measured with a handheld device. Serum was harvested from the remaining sample and submitted to a laboratory for measurement of BHBA and nonesterified fatty acid (NEFA) concentrations. β-Hydroxybutyrate concentration determined with the handheld device was compared with that determined by laboratory methods. The association between prepartum BHBA concentration and the development of hyperketonemia (BHBA concentration, ≥ 1.2 mmol/L) during the first week after parturition was determined. The agreement between prepartum BHBA and NEFA concentrations for identification of cows at risk of developing postpartum hyperketonemia was evaluated. β-Hydroxybutyrate concentration determined by the handheld device was moderately correlated with that determined by laboratory methods. Cows with a prepartum BHBA concentration ≥ 0.6 mmol/L were 2.2 times as likely to develop hyperketonemia within 1 week after parturition as were cows with a prepartum BHBA concentration < 0.6 mmol/L. There was substantial agreement between prepartum BHBA and NEFA concentrations for identification of cows at risk of developing postpartum hyperketonemia. Results indicated the handheld device was a valid tool for measurement of BHBA concentration in prepartum dairy cattle, and measurement of prepartum BHBA concentration may be helpful for identifying cows at risk of developing postpartum hyperketonemia.

Practical applications of hand-held computers in dermatology.

PubMed

Goldblum, Orin M

2002-09-01

For physicians, hand-held computers are gaining popularity as point of care reference tools. The convergence of hand-held computers, the Internet, and wireless networks will enable these devices to assume more essential roles as mobile transmitters and receivers of digital medical Information. In addition to serving as portable medical reference sources, these devices can be Internet-enabled, allowing them to communicate over wireless wide and local area networks. With enhanced wireless connectivity, hand-held computers can be used at the point of patient care for charge capture, electronic prescribing, laboratory test ordering, laboratory result retrieval, web access, e-mail communication, and other clinical and administrative tasks. Physicians In virtually every medical specialty have begun using these devices in various ways. This review of hand-held computer use in dermatology illustrates practical examples of the many different ways hand-held computers can be effectively used by the practicing dermatologist.

Design and testing of prototype handheld scanning probes for optical coherence tomography

PubMed Central

Demian, Dorin; Sinescu, Cosmin; Negrutiu, Meda Lavinia; Cernat, Ramona; Topala, Florin Ionel; Hutiu, Gheorghe; Bradu, Adrian; Podoleanu, Adrian Gh

2014-01-01

Three simple and low-cost configurations of handheld scanning probes for optical coherence tomography have been developed. Their design and testing for dentistry applications are presented. The first two configurations were built exclusively from available off-the-shelf optomechanical components, which, to the best of our knowledge, are the first designs of this type. The third configuration includes these components in an optimized and ergonomic probe. All the designs are presented in detail to allow for their duplication in any laboratory with a minimum effort, for applications that range from educational to high-end clinical investigations. Requirements that have to be fulfilled to achieve configurations which are reliable, ergonomic—for clinical environments, and easy to build are presented. While a range of applications is possible for the prototypes developed, in this study the handheld probes are tested ex vivo with a spectral domain optical coherence tomography system built in-house, for dental constructs. A previous testing with a swept source optical coherence tomography system has also been performed both in vivo and ex vivo for ear, nose, and throat—in a medical environment. The applications use the capability of optical coherence tomography to achieve real-time, high-resolution, non-contact, and non-destructive interferometric investigations with micrometer resolutions and millimeter penetration depth inside the sample. In this study, testing the quality of the material of one of the most used types of dental prosthesis, metalo-ceramic is thus demonstrated. PMID:25107512

Design and testing of prototype handheld scanning probes for optical coherence tomography.

PubMed

Demian, Dorin; Duma, Virgil-Florin; Sinescu, Cosmin; Negrutiu, Meda Lavinia; Cernat, Ramona; Topala, Florin Ionel; Hutiu, Gheorghe; Bradu, Adrian; Podoleanu, Adrian Gh

2014-08-01

Three simple and low-cost configurations of handheld scanning probes for optical coherence tomography have been developed. Their design and testing for dentistry applications are presented. The first two configurations were built exclusively from available off-the-shelf optomechanical components, which, to the best of our knowledge, are the first designs of this type. The third configuration includes these components in an optimized and ergonomic probe. All the designs are presented in detail to allow for their duplication in any laboratory with a minimum effort, for applications that range from educational to high-end clinical investigations. Requirements that have to be fulfilled to achieve configurations which are reliable, ergonomic-for clinical environments, and easy to build are presented. While a range of applications is possible for the prototypes developed, in this study the handheld probes are tested ex vivo with a spectral domain optical coherence tomography system built in-house, for dental constructs. A previous testing with a swept source optical coherence tomography system has also been performed both in vivo and ex vivo for ear, nose, and throat-in a medical environment. The applications use the capability of optical coherence tomography to achieve real-time, high-resolution, non-contact, and non-destructive interferometric investigations with micrometer resolutions and millimeter penetration depth inside the sample. In this study, testing the quality of the material of one of the most used types of dental prosthesis, metalo-ceramic is thus demonstrated. © IMechE 2014.

High-resolution handheld rigid endomicroscope based on full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Benoit a la Guillaume, Emilie; Martins, Franck; Boccara, Claude; Harms, Fabrice

2016-02-01

Full-field optical coherence tomography (FF-OCT) is a powerful tool for nondestructive assessment of biological tissue, i.e., for the structural examination of tissue in depth at a cellular resolution. Mostly known as a microscopy device for ex vivo analysis, FF-OCT has also been adapted to endoscopy setups since it shows good potential for in situ cancer diagnosis and biopsy guidance. Nevertheless, all the attempts to perform endoscopic FF-OCT imaging did not go beyond lab setups. We describe here, to the best of our knowledge, the first handheld FF-OCT endoscope based on a tandem interferometry assembly using incoherent illumination. A common-path passive imaging interferometer at the tip of an optical probe makes it robust and insensitive to environmental perturbations, and a low finesse Fabry-Perot processing interferometer guarantees a compact system. A good resolution (2.7 μm transverse and 6 μm axial) is maintained through the long distance, small diameter relay optics of the probe, and a good signal-to-noise ratio is achieved in a limited 100 ms acquisition time. High-resolution images and a movie of a rat brain slice have been recorded by moving the contact endoscope over the surface of the sample, allowing for tissue microscopic exploration at 20 μm under the surface. These promising ex vivo results open new perspectives for in vivo imaging of biological tissue, in particular, in the field of cancer and surgical margin assessment.

MOEMS optical delay line for optical coherence tomography

NASA Astrophysics Data System (ADS)

Choudhary, Om P.; Chouksey, S.; Sen, P. K.; Sen, P.; Solanki, J.; Andrews, J. T.

2014-09-01

Micro-Opto-Electro-Mechanical optical coherence tomography, a lab-on-chip for biomedical applications is designed, studied, fabricated and characterized. To fabricate the device standard PolyMUMPS processes is adopted. We report the utilization of electro-optic modulator for a fast scanning optical delay line for time domain optical coherence tomography. Design optimization are performed using Tanner EDA while simulations are performed using COMSOL. The paper summarizes various results and fabrication methodology adopted. The success of the device promises a future hand-held or endoscopic optical coherence tomography for biomedical applications.

MEMS-Based Handheld Fourier Domain Doppler Optical Coherence Tomography for Intraoperative Microvascular Anastomosis Imaging

PubMed Central

Huang, Yong; Furtmüller, Georg J.; Tong, Dedi; Zhu, Shan; Lee, W. P. Andrew; Brandacher, Gerald; Kang, Jin U.

2014-01-01

Purpose To demonstrate the feasibility of a miniature handheld optical coherence tomography (OCT) imager for real time intraoperative vascular patency evaluation in the setting of super-microsurgical vessel anastomosis. Methods A novel handheld imager Fourier domain Doppler optical coherence tomography based on a 1.3-µm central wavelength swept source for extravascular imaging was developed. The imager was minimized through the adoption of a 2.4-mm diameter microelectromechanical systems (MEMS) scanning mirror, additionally a 12.7-mm diameter lens system was designed and combined with the MEMS mirror to achieve a small form factor that optimize functionality as a handheld extravascular OCT imager. To evaluate in-vivo applicability, super-microsurgical vessel anastomosis was performed in a mouse femoral vessel cut and repair model employing conventional interrupted suture technique as well as a novel non-suture cuff technique. Vascular anastomosis patency after clinically successful repair was evaluated using the novel handheld OCT imager. Results With an adjustable lateral image field of view up to 1.5 mm by 1.5 mm, high-resolution simultaneous structural and flow imaging of the blood vessels were successfully acquired for BALB/C mouse after orthotopic hind limb transplantation using a non-suture cuff technique and BALB/C mouse after femoral artery anastomosis using a suture technique. We experimentally quantify the axial and lateral resolution of the OCT to be 12.6 µm in air and 17.5 µm respectively. The OCT has a sensitivity of 84 dB and sensitivity roll-off of 5.7 dB/mm over an imaging range of 5 mm. Imaging with a frame rate of 36 Hz for an image size of 1000(lateral)×512(axial) pixels using a 50,000 A-lines per second swept source was achieved. Quantitative vessel lumen patency, lumen narrowing and thrombosis analysis were performed based on acquired structure and Doppler images. Conclusions A miniature handheld OCT imager that can be used for

Development of fluorescence based handheld imaging devices for food safety inspection

NASA Astrophysics Data System (ADS)

Lee, Hoyoung; Kim, Moon S.; Chao, Kuanglin; Lefcourt, Alan M.; Chan, Diane E.

2013-05-01

For sanitation inspection in food processing environment, fluorescence imaging can be a very useful method because many organic materials reveal unique fluorescence emissions when excited by UV or violet radiation. Although some fluorescence-based automated inspection instrumentation has been developed for food products, there remains a need for devices that can assist on-site inspectors performing visual sanitation inspection of the surfaces of food processing/handling equipment. This paper reports the development of an inexpensive handheld imaging device designed to visualize fluorescence emissions and intended to help detect the presence of fecal contaminants, organic residues, and bacterial biofilms at multispectral fluorescence emission bands. The device consists of a miniature camera, multispectral (interference) filters, and high power LED illumination. With WiFi communication, live inspection images from the device can be displayed on smartphone or tablet devices. This imaging device could be a useful tool for assessing the effectiveness of sanitation procedures and for helping processors to minimize food safety risks or determine potential problem areas. This paper presents the design and development including evaluation and optimization of the hardware components of the imaging devices.

Fast, cheap and in control: spectral imaging with handheld devices

NASA Astrophysics Data System (ADS)

Gooding, Edward A.; Deutsch, Erik R.; Huehnerhoff, Joseph; Hajian, Arsen R.

2017-05-01

Remote sensing has moved out of the laboratory and into the real world. Instruments using reflection or Raman imaging modalities become faster, cheaper and more powerful annually. Enabling technologies include virtual slit spectrometer design, high power multimode diode lasers, fast open-loop scanning systems, low-noise IR-sensitive array detectors and low-cost computers with touchscreen interfaces. High-volume manufacturing assembles these components into inexpensive portable or handheld devices that make possible sophisticated decision-making based on robust data analytics. Examples include threat, hazmat and narcotics detection; remote gas sensing; biophotonic screening; environmental remediation and a host of other applications.

Handheld Computing

DTIC Science & Technology

2005-06-01

company has devel- oped an exciting prototype technology: … that lets users of PDAs and similar mobile devices put data into their handheld systems...for a class of small, easily carried electronic devices used to store and retrieve infor- mation” [2], were at one time viewed as lit- tle more than...some of the many ways that PDA technology is currently being used within the DoD: • The Pocket-Sized Forward Entry Device (PFED) is a ruggedized PDA

Optical-to-optical interface device

NASA Technical Reports Server (NTRS)

Jacobson, A. D.; Bleha, W. P.; Miller, L.; Grinberg, J.; Fraas, L.; Margerum, D.

1975-01-01

An investigation was conducted to develop an optical-to-optical interface device capable of performing real-time incoherent-to-incoherent optical image conversion. The photoactivated liquid crystal light valve developed earlier represented a prototype liquid crystal light valve device capable of performing these functions. A device was developed which had high performance and extended lifetime.

Doctors' experience with handheld computers in clinical practice: qualitative study.

PubMed

McAlearney, Ann Scheck; Schweikhart, Sharon B; Medow, Mitchell A

2004-05-15

To examine doctors' perspectives about their experiences with handheld computers in clinical practice. Qualitative study of eight focus groups consisting of doctors with diverse training and practice patterns. Six practice settings across the United States and two additional focus group sessions held at a national meeting of general internists. 54 doctors who did or did not use handheld computers. Doctors who used handheld computers in clinical practice seemed generally satisfied with them and reported diverse patterns of use. Users perceived that the devices helped them increase productivity and improve patient care. Barriers to use concerned the device itself and personal and perceptual constraints, with perceptual factors such as comfort with technology, preference for paper, and the impression that the devices are not easy to use somewhat difficult to overcome. Participants suggested that organisations can help promote handheld computers by providing advice on purchase, usage, training, and user support. Participants expressed concern about reliability and security of the device but were particularly concerned about dependency on the device and over-reliance as a substitute for clinical thinking. Doctors expect handheld computers to become more useful, and most seem interested in leveraging (getting the most value from) their use. Key opportunities with handheld computers included their use as a stepping stone to build doctors' comfort with other information technology and ehealth initiatives and providing point of care support that helps improve patient care.

Handheld Technology Acceptance in Radiologic Science Education and Training Programs

ERIC Educational Resources Information Center

Powers, Kevin Jay

2012-01-01

The purpose of this study was to explore the behavioral intention of directors of educational programs in the radiologic sciences to adopt handheld devices to aid in managing student clinical data. Handheld devices were described to participants as a technology representing a class of mobile electronic devices including, but not limited to,…

Optic Nerve Head Development in Healthy Infants and Children Using Handheld Spectral-Domain Optical Coherence Tomography.

PubMed

Patel, Aarti; Purohit, Ravi; Lee, Helena; Sheth, Viral; Maconachie, Gail; Papageorgiou, Eleni; McLean, Rebecca J; Gottlob, Irene; Proudlock, Frank A

2016-10-01

To determine feasibility of optic nerve head (ONH) imaging and to characterize ONH development in full-term infants without sedation using handheld spectral-domain optical coherence tomography (SD OCT). Prospective cross-sectional study. Three hundred fifty-two children aged between 1 day and 13 years. All participants were imaged using handheld SD OCT without sedation during a single scan session. The percentage of successful scans was calculated. Interexaminer reproducibility and differences between right and left eyes were assessed using intraclass correlation coefficients (ICCs). Images were analyzed using ImageJ software. The developmental trajectories over time for ONH parameters were calculated using fractional polynomial modelling. Disc and cup diameter (expressed as distance in micrometers and visual angle in degrees), cup depth, Bruch's membrane opening-minimum rim width (BMO-MRW), retinal thickness, and retinal nerve fiber layer (RNFL; 1700 μm and 6° from the disc center). On average, 70% of participants were imaged successfully. Interexaminer reliability was excellent (ICC, >0.89) for diametric and retinal thickness parameters. Right and left eyes were similar for diametric measurements (ICC, >0.79), but more variable for nasal BMO-MRW, RNFL, and retinal thickness. The mean disc and cup diameter increase by 30% and 40%, respectively, between birth and 13 years of age when expressed as a distance measure, but remained constant (at 5°-5.5° and 2°, respectively) when expressed as a visual angle with reference to the eye nodal point. The peripapillary temporal RNFL demonstrated a marked initial decrease of nearly 35% between birth and approximately 18 months of age. This was followed by a slow increase up to 12 years of age when measured at 1700 μm from the disc center, although there was little change when measured at 6° from the disc center. We demonstrated feasibility of handheld SD OCT imaging of the ONH in full-term infants and children without

Optical to optical interface device

NASA Technical Reports Server (NTRS)

Oliver, D. S.; Vohl, P.; Nisenson, P.

1972-01-01

The development, fabrication, and testing of a preliminary model of an optical-to-optical (noncoherent-to-coherent) interface device for use in coherent optical parallel processing systems are described. The developed device demonstrates a capability for accepting as an input a scene illuminated by a noncoherent radiation source and providing as an output a coherent light beam spatially modulated to represent the original noncoherent scene. The converter device developed under this contract employs a Pockels readout optical modulator (PROM). This is a photosensitive electro-optic element which can sense and electrostatically store optical images. The stored images can be simultaneously or subsequently readout optically by utilizing the electrostatic storage pattern to control an electro-optic light modulating property of the PROM. The readout process is parallel as no scanning mechanism is required. The PROM provides the functions of optical image sensing, modulation, and storage in a single active material.

Utility of hand-held devices in diagnosis and triage of cardiovascular emergencies. Observations during implementation of a PACS-based system in an acute aortic syndrome (AAS) network.

PubMed

Matar, Ralph; Renapurkar, Rahul; Obuchowski, Nancy; Menon, Venu; Piraino, David; Schoenhagen, Paul

2015-01-01

Prompt diagnosis and early referral to specialized centers is critical for patients presenting with cardiovascular emergencies, including acute aortic syndromes (AAS). Prior data has suggested that mobile access to imaging studies with hand-held devices can accelerate diagnosis and management. We conducted a study to determine the diagnostic accuracy of a hand-held device compared to conventional dedicated work-stations for diagnosing a spectrum of cardiovascular emergencies, predominantly acute aortic pathology. This study included 104 cases who underwent computed tomography (CT)-scan during "on-call'' hours between January, 2013 and August, 2014 for suspected AAS. Assessment was performed on a hand-held device independently by two readers using an iPhone5 connected via secure connection to web-based PACS servers. The subsequent interpretation from a dedicated workstation coupled with the diagnosis at the time of discharge was used as the reference standard for determining the presence or absence of an acute abnormality. Sensitivity and Specificity were calculated on a per patient basis. Readers' sensitivity and specificity using the hand-held device to diagnose acute chest pathology were calculated. Hand-held device evaluation was determined to have a sensitivity of 85.2% and a specificity of 98.6% by reader A and a sensitivity of 96.3% and specificity of 100% by reader B. Of 103 cases interpreted by both readers, the readers agreed about the diagnosis in 98 cases (95.1%). This study demonstrates that hand-held devices can be a potential useful tool to assist in diagnosis and triage of patients presenting with cardiovascular emergencies. Further studies are needed to assess the impact of screen size and resolution. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Finger tracking for hand-held device interface using profile-matching stereo vision

NASA Astrophysics Data System (ADS)

Chang, Yung-Ping; Lee, Dah-Jye; Moore, Jason; Desai, Alok; Tippetts, Beau

2013-01-01

Hundreds of millions of people use hand-held devices frequently and control them by touching the screen with their fingers. If this method of operation is being used by people who are driving, the probability of deaths and accidents occurring substantially increases. With a non-contact control interface, people do not need to touch the screen. As a result, people will not need to pay as much attention to their phones and thus drive more safely than they would otherwise. This interface can be achieved with real-time stereovision. A novel Intensity Profile Shape-Matching Algorithm is able to obtain 3-D information from a pair of stereo images in real time. While this algorithm does have a trade-off between accuracy and processing speed, the result of this algorithm proves the accuracy is sufficient for the practical use of recognizing human poses and finger movement tracking. By choosing an interval of disparity, an object at a certain distance range can be segmented. In other words, we detect the object by its distance to the cameras. The advantage of this profile shape-matching algorithm is that detection of correspondences relies on the shape of profile and not on intensity values, which are subjected to lighting variations. Based on the resulting 3-D information, the movement of fingers in space from a specific distance can be determined. Finger location and movement can then be analyzed for non-contact control of hand-held devices.

75 FR 8400 - In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

... Communications System Server Software, Wireless Handheld Devices and Battery Packs; Notice of Investigation..., wireless handheld devices and battery packs by reason of infringement of certain claims of U.S. Patent Nos... certain wireless communications system server software, wireless handheld devices or battery packs that...

Doctors' experience with handheld computers in clinical practice: qualitative study

PubMed Central

McAlearney, Ann Scheck; Schweikhart, Sharon B; Medow, Mitchell A

2004-01-01

Objective To examine doctors' perspectives about their experiences with handheld computers in clinical practice. Design Qualitative study of eight focus groups consisting of doctors with diverse training and practice patterns. Setting Six practice settings across the United States and two additional focus group sessions held at a national meeting of general internists. Participants 54 doctors who did or did not use handheld computers. Results Doctors who used handheld computers in clinical practice seemed generally satisfied with them and reported diverse patterns of use. Users perceived that the devices helped them increase productivity and improve patient care. Barriers to use concerned the device itself and personal and perceptual constraints, with perceptual factors such as comfort with technology, preference for paper, and the impression that the devices are not easy to use somewhat difficult to overcome. Participants suggested that organisations can help promote handheld computers by providing advice on purchase, usage, training, and user support. Participants expressed concern about reliability and security of the device but were particularly concerned about dependency on the device and over-reliance as a substitute for clinical thinking. Conclusions Doctors expect handheld computers to become more useful, and most seem interested in leveraging (getting the most value from) their use. Key opportunities with handheld computers included their use as a stepping stone to build doctors' comfort with other information technology and ehealth initiatives and providing point of care support that helps improve patient care. PMID:15142920

Integrated optical detection of autonomous capillary microfluidic immunoassays:a hand-held point-of-care prototype.

PubMed

Novo, P; Chu, V; Conde, J P

2014-07-15

The miniaturization of biosensors using microfluidics has potential in enabling the development of point-of-care devices, with the added advantages of reduced time and cost of analysis with limits-of-detection comparable to those obtained through traditional laboratory techniques. Interfacing microfluidic devices with the external world can be difficult especially in aspects involving fluid handling and the need for simple sample insertion that avoids special equipment or trained personnel. In this work we present a point-of-care prototype system by integrating capillary microfluidics with a microfabricated photodiode array and electronic instrumentation into a hand-held unit. The capillary microfluidic device is capable of autonomous and sequential fluid flow, including control of the average fluid velocity at any given point of the analysis. To demonstrate the functionality of the prototype, a model chemiluminescence ELISA was performed. The performance of the integrated optical detection in the point-of-care prototype is equal to that obtained with traditional bench-top instrumentation. The photodiode signals were acquired, displayed and processed by a simple graphical user interface using a computer connected to the microcontroller through USB. The prototype performed integrated chemiluminescence ELISA detection in about 15 min with a limit-of-detection of ≈2 nM with an antibody-antigen affinity constant of ≈2×10(7) M(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

75 FR 448 - In the Matter of: Certain Authentication Systems, Including Software and Handheld Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-05

... Systems, Including Software and Handheld Electronic Devices; Notice of Investigation AGENCY: U.S... software and handheld electronic devices, by reason of infringement of certain claims of U.S. Patent No 7... software and handheld electronic devices, that infringe one or more of claims 31-35, 38, 41, 51, 54, 56, 58...

TealLock 5.20 security software program for handheld devices.

PubMed

Tahil, Fatimah A

2004-07-01

The TealLock has a simple graphic interface, and the program is user-friendly with well thought out options to customize security settings. The program is inexpensive and works seamlessly with the Palm OS platform's built-in basic Security application. The developer offers a 30-day free trial version and there is no downside to trying it to see if it meets your needs. It seems to be an effective security software program for psychiatrists who keep confidential and sensitive patient information on their PDAs. In keeping with HIPAA regulations, the TealLock bolsters security for protected health information stored on PDAs or other handheld devices by providing safeguards that address authentication, access control, encryption, and selected aspects of transmission.

Distance and devices - potential barriers to use of wireless handheld devices.

PubMed

Martyn, Julie; Larkin, Kevin; Sander, Teresa; Yuginovich, Trudy; Jamieson-Proctor, Romina

2014-03-01

This paper reports the findings of a research project investigating the use of iPods by student nurses to enhance their interactions with content, instructors and peers while located at a distance from their university campus. Wireless handheld devices (WHD) are an important tool in nursing environments that are undergoing rapid technological change. Preferred treatments, drug dosages, postsurgical care, and preventive healthcare regimens continually change and such devices allow students to rapidly confirm information while in the clinical area, thus fostering active learning and safe practice. A case study approach was adopted with each participating student cohort comprising a case. Multiple data collection methods were used to enable rich descriptions of each case. This paper focusses on factors, relating to the use of iPods, which influenced student learning in distance courses at two regional Queensland universities. It furthermore highlights a range of creative interventions reported by students and educators in resolving issues with their devices. The study found that connectivity difficulties, technology literacy level, compatibility of study resources with the WHDs, and small screen size were all factors that impacted negatively on the use of iPods in distance courses. The paper describes the responses of students and educators to the use of iPods for learning. This study concluded that nursing students and nursing educators alike may experience problems when WHD's are introduced to courses as a platform for learning. However, both students and educators can be innovative and resourceful in managing these problems and, when access to course resources that were enabled for viewing on the WHDs were available, the learning experience of the students and the teaching experience for the educators were enhanced. Copyright © 2013 Elsevier Ltd. All rights reserved.

Developing a compact multiple laser diode combiner with a single fiber stub output for handheld IoT devices

NASA Astrophysics Data System (ADS)

Lee, Minseok; June, Seunghyeok; Kim, Sehwan

2018-01-01

Many biomedical applications require an efficient combination and localization of multiple discrete light sources ( e.g., fluorescence and absorbance imaging). We present a compact 6 channel combiner that couples the output of independent solid-state light sources into a single 400-μm-diameter fiber stub for handheld Internet of Things (IoT) devices. We demonstrate average coupling efficiencies > 80% for each of the 6 laser diodes installed into the prototype. The design supports the use of continuous wave and intensity-modulated laser diodes. This fiber-stub-type beam combiner could be used to construct custom multi-wavelength sources for tissue oximeters, microscopes and molecular imaging technologies. In order to validate its suitability, we applied the developed fiber-stub-type beam combiner to a multi-wavelength light source for a handheld IoT device and demonstrated its feasibility for smart healthcare through a tumor-mimicking silicon phantom.

A Novel Hand-Held Optical Imager with Real-Time Coregistration Facilities Toward Diagnostic Mammography

DTIC Science & Technology

2011-01-01

Journal Publications (1) S.J. Erickson, S.L. Martinez, J. Gonzalez, L. Caldera , and A. Godavarty. “Improved detection limits using a hand-held...Erickson, S. Martinez, J. Gonzalez, L. Caldera , and A. Godavarty. “Non- invasive Diagnostic Breast Imaging using a Hand-held Optical Imager...Proceedings of the 14th World Multi-Conference on Systems, Cybernetics and Informatics, 2010. (4) S.J. Erickson, S. Martinez, L. Caldera , and A

Textbooks on tap: using electronic books housed in handheld devices in nursing clinical courses.

PubMed

Williams, Margaret G; Dittmer, Arlis

2009-01-01

Changing technology is creating new ways to approach nursing education and practice. Beginning in 2003, using a quasi-experimental design, this project introduced personal digital assistants (PDAs) as a clinical tool to five experimental and control groups of students and faculty. The handheld device, or PDA, was loaded with e-books for clinical practice. Differences in learning styles and preferences emerged during the different phases of the study. Students were quickly able to master the technology and use the device effectively, reporting that they liked the concise nature of the information obtained. No students expressed dissatisfaction or regret at being in the experimental group. Results and implications for clinical practice, education, and library resources are discussed.

Fiber-optic fluorescence imaging

PubMed Central

Flusberg, Benjamin A; Cocker, Eric D; Piyawattanametha, Wibool; Jung, Juergen C; Cheung, Eunice L M; Schnitzer, Mark J

2010-01-01

Optical fibers guide light between separate locations and enable new types of fluorescence imaging. Fiber-optic fluorescence imaging systems include portable handheld microscopes, flexible endoscopes well suited for imaging within hollow tissue cavities and microendoscopes that allow minimally invasive high-resolution imaging deep within tissue. A challenge in the creation of such devices is the design and integration of miniaturized optical and mechanical components. Until recently, fiber-based fluorescence imaging was mainly limited to epifluorescence and scanning confocal modalities. Two new classes of photonic crystal fiber facilitate ultrashort pulse delivery for fiber-optic two-photon fluorescence imaging. An upcoming generation of fluorescence imaging devices will be based on microfabricated device components. PMID:16299479

Handheld ultrahigh speed swept source optical coherence tomography instrument using a MEMS scanning mirror.

PubMed

Lu, Chen D; Kraus, Martin F; Potsaid, Benjamin; Liu, Jonathan J; Choi, Woojhon; Jayaraman, Vijaysekhar; Cable, Alex E; Hornegger, Joachim; Duker, Jay S; Fujimoto, James G

2013-12-20

We developed an ultrahigh speed, handheld swept source optical coherence tomography (SS-OCT) ophthalmic instrument using a 2D MEMS mirror. A vertical cavity surface-emitting laser (VCSEL) operating at 1060 nm center wavelength yielded a 350 kHz axial scan rate and 10 µm axial resolution in tissue. The long coherence length of the VCSEL enabled a 3.08 mm imaging range with minimal sensitivity roll-off in tissue. Two different designs with identical optical components were tested to evaluate handheld OCT ergonomics. An iris camera aided in alignment of the OCT beam through the pupil and a manual fixation light selected the imaging region on the retina. Volumetric and high definition scans were obtained from 5 undilated normal subjects. Volumetric OCT data was acquired by scanning the 2.4 mm diameter 2D MEMS mirror sinusoidally in the fast direction and linearly in the orthogonal slow direction. A second volumetric sinusoidal scan was obtained in the orthogonal direction and the two volumes were processed with a software algorithm to generate a merged motion-corrected volume. Motion-corrected standard 6 x 6 mm(2) and wide field 10 x 10 mm(2) volumetric OCT data were generated using two volumetric scans, each obtained in 1.4 seconds. High definition 10 mm and 6 mm B-scans were obtained by averaging and registering 25 B-scans obtained over the same position in 0.57 seconds. One of the advantages of volumetric OCT data is the generation of en face OCT images with arbitrary cross sectional B-scans registered to fundus features. This technology should enable screening applications to identify early retinal disease, before irreversible vision impairment or loss occurs. Handheld OCT technology also promises to enable applications in a wide range of settings outside of the traditional ophthalmology or optometry clinics including pediatrics, intraoperative, primary care, developing countries, and military medicine.

Design and Implementation of an Intelligent Windowsill System Using Smart Handheld Device and Fuzzy Microcontroller

PubMed Central

Wang, Jing-Min; Yang, Ming-Ta; Chen, Po-Lin

2017-01-01

With the advance of science and technology, people have a desire for convenient and comfortable living. Creating comfortable and healthy indoor environments is a major consideration for designing smart homes. As handheld devices become increasingly powerful and ubiquitous, this paper proposes an innovative use of smart handheld devices (SHD), using MIT App Inventor and fuzzy control, to perform the real-time monitoring and smart control of the designed intelligent windowsill system (IWS) in a smart home. A compact weather station that consists of environment sensors was constructed in the IWS for measuring of indoor illuminance, temperature-humidity, carbon dioxide (CO2) concentration and outdoor rain and wind direction. According to the measured environment information, the proposed system can automatically send a command to a fuzzy microcontroller performed by Arduino UNO to fully or partly open the electric curtain and electric window for adapting to climate changes in the indoor and outdoor environment. Moreover, the IWS can automatically close windows for rain splashing on the window. The presented novel control method for the windowsill not only expands the SHD applications, but greatly enhances convenience to users. To validate the feasibility and effectiveness of the IWS, a laboratory prototype was built and confirmed experimentally. PMID:28398266

Design and Implementation of an Intelligent Windowsill System Using Smart Handheld Device and Fuzzy Microcontroller.

PubMed

Wang, Jing-Min; Yang, Ming-Ta; Chen, Po-Lin

2017-04-11

With the advance of science and technology, people have a desire for convenient and comfortable living. Creating comfortable and healthy indoor environments is a major consideration for designing smart homes. As handheld devices become increasingly powerful and ubiquitous, this paper proposes an innovative use of smart handheld devices (SHD), using MIT App Inventor and fuzzy control, to perform the real-time monitoring and smart control of the designed intelligent windowsill system (IWS) in a smart home. A compact weather station that consists of environment sensors was constructed in the IWS for measuring of indoor illuminance, temperature-humidity, carbon dioxide (CO₂) concentration and outdoor rain and wind direction. According to the measured environment information, the proposed system can automatically send a command to a fuzzy microcontroller performed by Arduino UNO to fully or partly open the electric curtain and electric window for adapting to climate changes in the indoor and outdoor environment. Moreover, the IWS can automatically close windows for rain splashing on the window. The presented novel control method for the windowsill not only expands the SHD applications, but greatly enhances convenience to users. To validate the feasibility and effectiveness of the IWS, a laboratory prototype was built and confirmed experimentally.

30 CFR 56.14116 - Hand-held power tools.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held power tools. 56.14116 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills...

30 CFR 56.14116 - Hand-held power tools.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held power tools. 56.14116 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills...

30 CFR 56.14116 - Hand-held power tools.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held power tools. 56.14116 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills...

30 CFR 57.14116 - Hand-held power tools.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held power tools. 57.14116 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills...

30 CFR 56.14116 - Hand-held power tools.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held power tools. 56.14116 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills...

30 CFR 57.14116 - Hand-held power tools.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held power tools. 57.14116 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills...

30 CFR 57.14116 - Hand-held power tools.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held power tools. 57.14116 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills...

30 CFR 56.14116 - Hand-held power tools.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held power tools. 56.14116 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills...

30 CFR 57.14116 - Hand-held power tools.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held power tools. 57.14116 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills...

30 CFR 57.14116 - Hand-held power tools.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held power tools. 57.14116 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills...

Nonlinear Optical Acrylic Polymers and Use Thereof in Optical and Electro-Optic Devices

DTIC Science & Technology

1992-01-07

COVERED 4. TITLE AND SUBTITLE Nonlinear Optical Acrylic Polymers and Use Thereof in Optical and Electro - Optic Devices 5a. CONTRACT NUMBER 5b. GRANT...generators, computational devices and the like. 15. SUBJECT TERMS optical devices, electro - optical devices, optical signal processing...THEREOF IN OPTICAL AND ELECTRO - OPTIC DEVICES [75] Inventors: Le*lie H. Sperling, Bethlehem; Clarence J. Murphy, Stroudsburg; Warren A. Rosen

Handheld Devices with Wide-Area Wireless Connectivity: Applications in Astronomy Educational Technology and Remote Computational Control

NASA Astrophysics Data System (ADS)

Budiardja, R. D.; Lingerfelt, E. J.; Guidry, M. W.

2003-05-01

Wireless technology implemented with handheld devices has attractive features because of the potential to access large amounts of data and the prospect of on-the-fly computational analysis from a device that can be carried in a shirt pocket. We shall describe applications of such technology to the general paradigm of making digital wireless connections from the field to upload information and queries to network servers, executing (potentially complex) programs and controlling data analysis and/or database operations on fast network computers, and returning real-time information from this analysis to the handheld device in the field. As illustration, we shall describe several client/server programs that we have written for applications in teaching introductory astronomy. For example, one program allows static and dynamic properties of astronomical objects to be accessed in a remote observation laboratory setting using a digital cell phone or PDA. Another implements interactive quizzing over a cell phone or PDA using a 700-question introductory astronomy quiz database, thus permitting students to study for astronomy quizzes in any environment in which they have a few free minutes and a digital cell phone or wireless PDA. Another allows one to control and monitor a computation done on a Beowulf cluster by changing the parameters of the computation remotely and retrieving the result when the computation is done. The presentation will include hands-on demonstrations with real devices. *Managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

Electro-optic component mounting device

DOEpatents

Gruchalla, M.E.

1994-09-13

A technique is provided for integrally mounting a device such as an electro-optic device in a transmission line to avoid series resonant effects. A center conductor of the transmission line has an aperture formed therein for receiving the device. The aperture splits the center conductor into two parallel sections on opposite sides of the device. For a waveguide application, the center conductor is surrounded by a conductive ground surface which is spaced apart from the center conductor with a dielectric material. One set of electrodes formed on the surface of the electro-optic device is directly connected to the center conductor and an electrode formed on the surface of the electro-optic device is directly connected to the conductive ground surface. The electrodes formed on the surface of the electro-optic device are formed on curved sections of the surface of the device to mate with correspondingly shaped electrodes on the conductor and ground surface to provide a uniform electric field across the electro-optic device. The center conductor includes a passage formed therein for passage of optical signals to an electro-optic device. 10 figs.

Electro-optic component mounting device

DOEpatents

Gruchalla, Michael E.

1994-01-01

A technique is provided for integrally mounting a device such as an electro-optic device (50) in a transmission line to avoid series resonant effects. A center conductor (52) of the transmission line has an aperture (58) formed therein for receiving the device (50). The aperture (58) splits the center conductor into two parallel sections on opposite sides of the device. For a waveguide application, the center conductor is surrounded by a conductive ground surface (54), which is spaced apart from the center conductor with a dielectric material (56). One set of electrodes formed on the surface of the electro-optic device (50) is directly connected to the center conductor 52 and an electrode formed on the surface of the electro-optic device is directly connected to the conductive ground surface (54). The electrodes formed on the surface of the electro-optic device are formed on curved sections of the surface of the device to mate with correspondingly shaped electrodes on the conductor and ground surface to provide a uniform electric field across the electro-optic device. The center conductor includes a passage ( 60) formed therein for passage of optical signals to an electro-optic device.

Wireless, Web-Based Interactive Control of Optical Coherence Tomography with Mobile Devices.

PubMed

Mehta, Rajvi; Nankivil, Derek; Zielinski, David J; Waterman, Gar; Keller, Brenton; Limkakeng, Alexander T; Kopper, Regis; Izatt, Joseph A; Kuo, Anthony N

2017-01-01

Optical coherence tomography (OCT) is widely used in ophthalmology clinics and has potential for more general medical settings and remote diagnostics. In anticipation of remote applications, we developed wireless interactive control of an OCT system using mobile devices. A web-based user interface (WebUI) was developed to interact with a handheld OCT system. The WebUI consisted of key OCT displays and controls ported to a webpage using HTML and JavaScript. Client-server relationships were created between the WebUI and the OCT system computer. The WebUI was accessed on a cellular phone mounted to the handheld OCT probe to wirelessly control the OCT system. Twenty subjects were imaged using the WebUI to assess the system. System latency was measured using different connection types (wireless 802.11n only, wireless to remote virtual private network [VPN], and cellular). Using a cellular phone, the WebUI was successfully used to capture posterior eye OCT images in all subjects. Simultaneous interactivity by a remote user on a laptop was also demonstrated. On average, use of the WebUI added only 58, 95, and 170 ms to the system latency using wireless only, wireless to VPN, and cellular connections, respectively. Qualitatively, operator usage was not affected. Using a WebUI, we demonstrated wireless and remote control of an OCT system with mobile devices. The web and open source software tools used in this project make it possible for any mobile device to potentially control an OCT system through a WebUI. This platform can be a basis for remote, teleophthalmology applications using OCT.

Wireless, Web-Based Interactive Control of Optical Coherence Tomography with Mobile Devices

PubMed Central

Mehta, Rajvi; Nankivil, Derek; Zielinski, David J.; Waterman, Gar; Keller, Brenton; Limkakeng, Alexander T.; Kopper, Regis; Izatt, Joseph A.; Kuo, Anthony N.

2017-01-01

Purpose Optical coherence tomography (OCT) is widely used in ophthalmology clinics and has potential for more general medical settings and remote diagnostics. In anticipation of remote applications, we developed wireless interactive control of an OCT system using mobile devices. Methods A web-based user interface (WebUI) was developed to interact with a handheld OCT system. The WebUI consisted of key OCT displays and controls ported to a webpage using HTML and JavaScript. Client–server relationships were created between the WebUI and the OCT system computer. The WebUI was accessed on a cellular phone mounted to the handheld OCT probe to wirelessly control the OCT system. Twenty subjects were imaged using the WebUI to assess the system. System latency was measured using different connection types (wireless 802.11n only, wireless to remote virtual private network [VPN], and cellular). Results Using a cellular phone, the WebUI was successfully used to capture posterior eye OCT images in all subjects. Simultaneous interactivity by a remote user on a laptop was also demonstrated. On average, use of the WebUI added only 58, 95, and 170 ms to the system latency using wireless only, wireless to VPN, and cellular connections, respectively. Qualitatively, operator usage was not affected. Conclusions Using a WebUI, we demonstrated wireless and remote control of an OCT system with mobile devices. Translational Relevance The web and open source software tools used in this project make it possible for any mobile device to potentially control an OCT system through a WebUI. This platform can be a basis for remote, teleophthalmology applications using OCT. PMID:28138415

Live broadcast of laparoscopic surgery to handheld computers.

PubMed

Gandsas, A; McIntire, K; Park, A

2004-06-01

Thanks to advances in computer power and miniaturization technology, portable electronic devices are now being used to assist physicians with various applications that extend far beyond Web browsing or sending e-mail. Handheld computers are used for electronic medical records, billing, coding, and to enable convenient access to electronic journals for reference purposes. The results of diagnostic investigations, such as laboratory results, study reports, and still radiographic pictures, can also be downloaded into portable devices for later view. Handheld computer technology, combined with wireless protocols and streaming video technology, has the added potential to become a powerful educational tool for medical students and residents. The purpose of this study was to assess the feasibility of transferring multimedia data in real time to a handheld computer via a wireless network and displaying them on the computer screens of clients at remote locations. A live laparoscopic splenectomy was transmitted live to eight handheld computers simultaneously through our institution's wireless network. All eight viewers were able to view the procedure and to hear the surgeon's comments throughout the entire duration of the operation. Handheld computer technology can play a key role in surgical education by delivering information to surgical residents or students when they are geographically distant from the actual event. Validation of this new technology by conducting clinical research is still needed to determine whether resident physicians or medical students can benefit from the use of handheld computers.

Handheld technology acceptance in radiologic science education and training programs

NASA Astrophysics Data System (ADS)

Powers, Kevin Jay

The purpose of this study was to explore the behavioral intention of directors of educational programs in the radiologic sciences to adopt handheld devices to aid in managing student clinical data. Handheld devices were described to participants as a technology representing a class of mobile electronic devices including, but not limited to, personal digital assistants such as a Palm TX, Apple iPod Touch, Apple iPad or Hewlett Packard iPaq, and cellular or smartphones with third generation mobile capabilities such as an Apple iPhone, Blackberry or Android device. The study employed a non-experimental, cross-sectional survey design to determine the potential of adopting handheld technologies based on the constructs of Davis's (1989) Technology Acceptance Model. An online self-report questionnaire survey instrument was used to gather study data from 551 entry level radiologic science programs specializing in radiography, radiation therapy, nuclear medicine and medical sonography. The study design resulted in a single point in time assessment of the relationship between the primary constructs of the Technology Acceptance Model: perceived usefulness and perceived ease of use, and the behavioral intention of radiography program directors to adopt the information technology represented by hand held devices. Study results provide justification for investing resources to promote the adoption of mobile handheld devices in radiologic science programs and study findings serve as a foundation for further research involving technology adoption in the radiologic sciences.

Motion-compensated hand-held common-path Fourier-domain optical coherence tomography probe for image-guided intervention

NASA Astrophysics Data System (ADS)

Huang, Yong; Song, Cheol; Liu, Xuan; Kang, Jin U.

2013-03-01

A motion-compensated hand-held common-path Fourier-domain optical coherence tomography imaging probe has been developed for image guided intervention during microsurgery. A hand-held prototype instrument was designed and fabricated by integrating an imaging fiber probe inside a stainless steel needle which is attached to the ceramic shaft of a piezoelectric motor housed in an aluminum handle. The fiber probe obtains A-scan images. The distance information was extracted from the A-scans to track the sample surface distance and a fixed distance was maintained by a feedback motor control which effectively compensated hand tremor and target movements in the axial direction. Graphical user interface, real-time data processing, and visualization based on a CPU-GPU hybrid programming architecture were developed and used in the implantation of this system. To validate the system, free-hand optical coherence tomography images using various samples were obtained. The system can be easily integrated into microsurgical tools and robotics for a wide range of clinical applications. Such tools could offer physicians the freedom to easily image sites of interest with reduced risk and higher image quality.

User-friendly tools on handheld devices for observer performance study

NASA Astrophysics Data System (ADS)

Matsumoto, Takuya; Hara, Takeshi; Shiraishi, Junji; Fukuoka, Daisuke; Abe, Hiroyuki; Matsusako, Masaki; Yamada, Akira; Zhou, Xiangrong; Fujita, Hiroshi

2012-02-01

ROC studies require complex procedures to select cases from many data samples, and to set confidence levels in each selected case to generate ROC curves. In some observer performance studies, researchers have to develop software with specific graphical user interface (GUI) to obtain confidence levels from readers. Because ROC studies could be designed for various clinical situations, it is difficult task for preparing software corresponding to every ROC studies. In this work, we have developed software for recording confidence levels during observer studies on tiny personal handheld devices such as iPhone, iPod touch, and iPad. To confirm the functions of our software, three radiologists performed observer studies to detect lung nodules by using public database of chest radiograms published by Japan Society of Radiological Technology. The output in text format conformed to the format for the famous ROC kit from the University of Chicago. Times required for the reading each case was recorded very precisely.

Optical devices integrated with semiconductor optical amplifier

NASA Astrophysics Data System (ADS)

Oh, Kwang R.; Park, Moon S.; Jeong, Jong S.; Baek, Yongsoon; Oh, Dae-Kon

2000-07-01

Semiconductor optical amplifiers (SOA's) have been used as a key optical component for the high capacity communication systems. The monolithic integration is necessary for the stable operation of these devices and the wider applications. In this paper, the coupling technique between different waveguides and the integration of SSC's are discussed and the research results of optical devices integrated with SOA's are presented.

An ergonomic handheld ultrasound probe providing contact forces and pose information.

PubMed

Yohan Noh; Housden, R James; Gomez, Alberto; Knight, Caroline; Garcia, Francesca; Hongbin Liu; Razavi, Reza; Rhode, Kawal; Althoefer, Kaspar

2015-08-01

This paper presents a handheld ultrasound probe which is integrated with sensors to measure force and pose (position/orientation) information. Using an integrated probe like this, one can relate ultrasound images to spatial location and create 3D ultrasound maps. The handheld device can be used by sonographers and also easily be integrated with robot arms for automated sonography. The handheld device is ergonomically designed; rapid attachment and removal of the ultrasound transducer itself is possible using easy-to-operate clip mechanisms. A cable locking mechanism reduces the impact that gravitational and other external forces have (originating from data and power supply cables connected to the probe) on our measurements. Gravitational errors introduced by the housing of the probe are compensated for using knowledge of the housing geometry and the integrated pose sensor that provides us with accurate orientation information. In this paper, we describe the handheld probe with its integrated force/pose sensors and our approach to gravity compensation. We carried out a set of experiments to verify the feasibility of our approach to obtain accurate spatial information of the handheld probe.

Handheld Devices and Video Modeling to Enhance the Learning of Self-Help Skills in Adolescents With Autism Spectrum Disorder.

PubMed

Campbell, Joseph E; Morgan, Michele; Barnett, Veronica; Spreat, Scott

2015-04-01

The viewing of videos is a much-studied intervention to teach self-help, social, and vocational skills. Many of the studies to date looked at video modeling using televisions, computers, and other large screens. This study looked at the use of video modeling on portable handheld devices to teach hand washing to three adolescent students with an autism spectrum disorder. Three students participated in this 4-week study conducted by occupational therapists. Baseline data were obtained for the first student for 1 week, the second for 2 weeks, and the third for 3 weeks; videos were introduced when the participants each finished the baseline phase. Given the cognitive and motor needs of the participants, the occupational therapist set the player so that the participants only had to press the play button to start the video playing. The participants were able to hold the players and view at distances that were most appropriate for their individual needs and preferences. The results suggest that video modeling on a handheld device improves the acquisition of self-help skills.

75 FR 36678 - In the Matter of Certain Authentication Systems, Including Software and Handheld Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-697] In the Matter of Certain Authentication Systems, Including Software and Handheld Electronic Devices; Notice of Commission Decision Not to... importation of certain authentication systems, including software and handheld electronic devices, by reason...

The transforming effect of handheld computers on nursing practice.

PubMed

Thompson, Brent W

2005-01-01

Handheld computers have the power to transform nursing care. The roots of this power are the shift to decentralization of communication, electronic health records, and nurses' greater need for information at the point of care. This article discusses the effects of handheld resources, calculators, databases, electronic health records, and communication devices on nursing practice. The US government has articulated the necessity of implementing the use of handheld computers in healthcare. Nurse administrators need to encourage and promote the diffusion of this technology, which can reduce costs and improve care.

Handheld, point-of-care laser speckle imaging

PubMed Central

Farraro, Ryan; Fathi, Omid; Choi, Bernard

2016-01-01

Abstract. Laser speckle imaging (LSI) enables measurement of relative changes in blood flow in biological tissues. We postulate that a point-of-care form factor will lower barriers to routine clinical use of LSI. Here, we describe a first-generation handheld LSI device based on a tablet computer. The coefficient of variation of speckle contrast was <2% after averaging imaging data collected over an acquisition period of 5.3 s. With a single, experienced user, handheld motion artifacts had a negligible effect on data collection. With operation by multiple users, we did not identify any significant difference (p>0.05) between the measured speckle contrast values using either a handheld or mounted configuration. In vivo data collected during occlusion experiments demonstrate that a handheld LSI is capable of both quantitative and qualitative assessment of changes in blood flow. Finally, as a practical application of handheld LSI, we collected data from a 53-day-old neonate with confirmed compromised blood flow in the hand. We readily identified with LSI a region of diminished blood flow in the thumb of the affected hand. Our data collectively suggest that handheld LSI is a promising technique to enable clinicians to obtain point-of-care measurements of blood flow. PMID:27579578

Handheld, point-of-care laser speckle imaging

NASA Astrophysics Data System (ADS)

Farraro, Ryan; Fathi, Omid; Choi, Bernard

2016-09-01

Laser speckle imaging (LSI) enables measurement of relative changes in blood flow in biological tissues. We postulate that a point-of-care form factor will lower barriers to routine clinical use of LSI. Here, we describe a first-generation handheld LSI device based on a tablet computer. The coefficient of variation of speckle contrast was <2% after averaging imaging data collected over an acquisition period of 5.3 s. With a single, experienced user, handheld motion artifacts had a negligible effect on data collection. With operation by multiple users, we did not identify any significant difference (p>0.05) between the measured speckle contrast values using either a handheld or mounted configuration. In vivo data collected during occlusion experiments demonstrate that a handheld LSI is capable of both quantitative and qualitative assessment of changes in blood flow. Finally, as a practical application of handheld LSI, we collected data from a 53-day-old neonate with confirmed compromised blood flow in the hand. We readily identified with LSI a region of diminished blood flow in the thumb of the affected hand. Our data collectively suggest that handheld LSI is a promising technique to enable clinicians to obtain point-of-care measurements of blood flow.

3D handheld endoscope for optical coherence tomography of the human oral mucosa in vivo

NASA Astrophysics Data System (ADS)

Walther, Julia; Schnabel, Christian; Ebert, Nadja; Baumann, Michael; Koch, Edmund

2017-07-01

The early non-invasive diagnosis of epithelial tissue alterations in daily clinical routine is still challenging. Since optical coherence tomography (OCT) shows the potential to differentiate between benign and malignant tissue of primal endothelium, OCT could be beneficial for the early diagnosis of malignancies in routine health checks. In this research, a new handheld endoscopic scanning unit was designed and connected to a spectral domain OCT system of our workgroup for the in vivo imaging of the human oral mucosa.

My-Mini-Pet: A Handheld Pet-Nurturing Game to Engage Students in Arithmetic Practices

ERIC Educational Resources Information Center

Liao, C. C. Y.; Chen, Z-H.; Cheng, H. N. H.; Chen, F-C.; Chan, T-W.

2011-01-01

In the last decade, more and more games have been developed for handheld devices. Furthermore, the popularity of handheld devices and increase of wireless computing can be taken advantage of to provide students with more learning opportunities. Games also could bring promising benefits--specifically, motivating students to learn/play, sustaining…

Feasibility of a handheld near infrared device for the qualitative analysis of bloodstains.

PubMed

Morillas, Alvaro Varela; Gooch, James; Frascione, Nunzianda

2018-07-01

One of the most common tasks in criminal investigation is to determine from which tissue source a biological fluid stain originates. As a result, there are many tests that are frequently used to determine if a stain is blood, semen or saliva by exploiting the properties of certain molecules present within the fluids themselves. These include chemical reagents such as the Kastle-Meyer or Acid Phosphatase tests, as well as other techniques like the use of alternative light sources. However, most of the tests currently available have some major drawbacks. In this study, a handheld near-infrared spectrometer is investigated for the specific identification of deposited bloodstains. First, a calibration was carried out by scanning over 500 positive (blood present) and negative (blood absent) samples to train several predictive models based on machine learning principles. These models were then tested on over 100 new positive and negative samples to evaluate their performance. All models tested were able to correctly classify deposited stains as blood in at least 81% of tested samples, with some models allowing for even higher classification accuracy at over 94%. This suggests that handheld near infrared devices could offer great opportunity for the rapid, low cost and non-destructive screening of body fluids at scenes of crime. Copyright © 2018 Elsevier B.V. All rights reserved.

75 FR 43206 - In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-23

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-706] In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld Devices and Battery Packs: Notice of Commission... handheld devices and battery packs by reason of infringement of certain claims of U.S. Patent Nos. 5,319...

Cordless hand-held optical 3D sensor

NASA Astrophysics Data System (ADS)

Munkelt, Christoph; Bräuer-Burchardt, Christian; Kühmstedt, Peter; Schmidt, Ingo; Notni, Gunther

2007-07-01

A new mobile optical 3D measurement system using phase correlation based fringe projection technique will be presented. The sensor consist of a digital projection unit and two cameras in a stereo arrangement, whereby both are battery powered. The data transfer to a base station will be done via WLAN. This gives the possibility to use the system in complicate, remote measurement situations, which are typical in archaeology and architecture. In the measurement procedure the sensor will be hand-held by the user, illuminating the object with a sequence of less than 10 fringe patterns, within a time below 200 ms. This short sequence duration was achieved by a new approach, which combines the epipolar constraint with robust phase correlation utilizing a pre-calibrated sensor head, containing two cameras and a digital fringe projector. Furthermore, the system can be utilized to acquire the all around shape of objects by using the phasogrammetric approach with virtual land marks introduced by the authors 1, 2. This way no matching procedures or markers are necessary for the registration of multiple views, which makes the system very flexible in accomplishing different measurement tasks. The realized measurement field is approx. 100 mm up to 400 mm in diameter. The mobile character makes the measurement system useful for a wide range of applications in arts, architecture, archaeology and criminology, which will be shown in the paper.

Performance assessments of Android-powered military applications operating on tactical handheld devices

NASA Astrophysics Data System (ADS)

Weiss, Brian A.; Fronczek, Lisa; Morse, Emile; Kootbally, Zeid; Schlenoff, Craig

2013-05-01

Transformative Apps (TransApps) is a Defense Advanced Research Projects Agency (DARPA) funded program whose goal is to develop a range of militarily-relevant software applications ("apps") to enhance the operational-effectiveness of military personnel on (and off) the battlefield. TransApps is also developing a military apps marketplace to facilitate rapid development and dissemination of applications to address user needs by connecting engaged communities of endusers with development groups. The National Institute of Standards and Technology's (NIST) role in the TransApps program is to design and implement evaluation procedures to assess the performance of: 1) the various software applications, 2) software-hardware interactions, and 3) the supporting online application marketplace. Specifically, NIST is responsible for evaluating 50+ tactically-relevant applications operating on numerous Android™-powered platforms. NIST efforts include functional regression testing and quantitative performance testing. This paper discusses the evaluation methodologies employed to assess the performance of three key program elements: 1) handheld-based applications and their integration with various hardware platforms, 2) client-based applications and 3) network technologies operating on both the handheld and client systems along with their integration into the application marketplace. Handheld-based applications are assessed using a combination of utility and usability-based checklists and quantitative performance tests. Client-based applications are assessed to replicate current overseas disconnected (i.e. no network connectivity between handhelds) operations and to assess connected operations envisioned for later use. Finally, networked applications are assessed on handhelds to establish baselines of performance for when connectivity will be common usage.

Assessment of a portable handheld UV light device for the disinfection of viruses and bacteria in water.

PubMed

Abd-Elmaksoud, Sherif; Naranjo, Jaime E; Gerba, Charles P

2013-06-01

Effective individual microbiological water purifiers are needed for consumption of untreated water sources by campers, emergency use, military, and in developing counties. A handheld UV light device was tested to assess if it could meet the virus reduction requirements established by the United State Environmental Protection Agency, National Science Foundation and the World Health Organization. The device was found capable of inactivating at least 4 log₁₀ of poliovirus type 1, rotavirus SA-11 and MS-2 virus in 500 mL volumes of general case test water. But in the presence of high turbidity and organic matter, filtration was necessary to achieve a 4 log₁₀ reduction of the test viruses.

Hand-held optical sensor using denatured antibody coated electro-active polymer for ultra-trace detection of copper in blood serum and environmental samples.

PubMed

Chandra, Sutapa; Dhawangale, Arvind; Mukherji, Soumyo

2018-07-01

An optimum copper concentration in environment is highly desired for all forms of life. We have developed an ultrasensitive copper sensor which functions from femto to micro molar concentration accurately (R 2 = 0.98). The sensor is based on denatured antibody immunoglobulin G (IgG), immobilized on polyaniline (PAni) which in turn is the coating on the core of an optical fiber. The sensing relies on changes in evanescent wave absorbance in the presence of the analyte. The sensor showed excellent selectivity towards Cu (II) ions over all other metal ions. The sensor was tested with lake and marine water samples to determine unknown concentrations of copper ions and the recovery results were within 90-115%, indicating reasonable accuracy. We further integrated the fiber-optic sensor with a miniaturized hand-held instrumentation platform to develop an accurate and field deployable device which can broadly be applicable to determine Cu (II) concentration in a wide range of systems - natural water bodies, soil as well as blood serum. Copyright © 2018 Elsevier B.V. All rights reserved.

Robust sleep quality quantification method for a personal handheld device.

PubMed

Shin, Hangsik; Choi, Byunghun; Kim, Doyoon; Cho, Jaegeol

2014-06-01

The purpose of this study was to develop and validate a novel method for sleep quality quantification using personal handheld devices. The proposed method used 3- or 6-axes signals, including acceleration and angular velocity, obtained from built-in sensors in a smartphone and applied a real-time wavelet denoising technique to minimize the nonstationary noise. Sleep or wake status was decided on each axis, and the totals were finally summed to calculate sleep efficiency (SE), regarded as sleep quality in general. The sleep experiment was carried out for performance evaluation of the proposed method, and 14 subjects participated. An experimental protocol was designed for comparative analysis. The activity during sleep was recorded not only by the proposed method but also by well-known commercial applications simultaneously; moreover, activity was recorded on different mattresses and locations to verify the reliability in practical use. Every calculated SE was compared with the SE of a clinically certified medical device, the Philips (Amsterdam, The Netherlands) Actiwatch. In these experiments, the proposed method proved its reliability in quantifying sleep quality. Compared with the Actiwatch, accuracy and average bias error of SE calculated by the proposed method were 96.50% and -1.91%, respectively. The proposed method was vastly superior to other comparative applications with at least 11.41% in average accuracy and at least 6.10% in average bias; average accuracy and average absolute bias error of comparative applications were 76.33% and 17.52%, respectively.

Optical signal splitting and chirping device modeling

NASA Astrophysics Data System (ADS)

Vinogradova, Irina L.; Andrianova, Anna V.; Meshkov, Ivan K.; Sultanov, Albert Kh.; Abdrakhmanova, Guzel I.; Grakhova, Elizaveta P.; Ishmyarov, Arsen A.; Yantilina, Liliya Z.; Kutlieva, Gulnaz R.

2017-04-01

This article examines the devices for optical signal splitting and chirping device modeling. Models with splitting and switching functions are taken into consideration. The described device for optical signal splitting and chirping represents interferential splitter with profiled mixer which provides allocation of correspondent spectral component from ultra wide band frequency diapason, and signal phase shift for aerial array (AA) directive diagram control. This paper proposes modeling for two types of devices for optical signal splitting and chirping: the interference-type optical signal splitting and chirping device and the long-distance-type optical signal splitting and chirping device.

Handheld Universal Diagnostic Sensor

NASA Technical Reports Server (NTRS)

Chan, Eugene

2012-01-01

The rHEALTH technology is designed to shrink an entire hospital testing laboratory onto a handheld device. A physician or healthcare provider performs the test by collecting a fingerstick of blood from a patient. The tiny volume of blood is inserted into the rHEALTH device. Inside the device is a microfluidic chip that contains small channels about the width of a human hair. These channels help move the blood and analyze the blood sample. The rHEALTH sensor uses proprietary reagents called nanostrips, which are nanoscale test strips that enable the clinical assays. The readout is performed by laser-induced fluorescence. Overall, the time from blood collection through analysis is less than a minute.

Fiber optic-based optical coherence tomography (OCT) for dental applications

NASA Astrophysics Data System (ADS)

Everett, Matthew J.; Colston, Bill W., Jr.; Da Silva, Luiz B.; Otis, Linda L.

1998-09-01

We have developed a hand-held fiber optic based optical coherence tomography (OCT) system for scanning of the oral cavity. We have produced, using this scanning device, in vivo cross-sectional images of hard and soft dental tissues in human volunteers. Clinically relevant anatomical structures, including the gingival margin, periodontal sulcus, and dento- enamel junction, were visible in all the images. The cemento- enamel junction and the alveolar bone were identified in approximately two thirds of the images. These images represent, or our knowledge, the first in vivo OCT images of human dental tissue.

Long-term effects of handheld cell phone laws on driver handheld cell phone use.

PubMed

McCartt, Anne T; Hellinga, Laurie A; Strouse, Laura M; Farmer, Charles M

2010-04-01

As of October 2009, seven U.S. states and the District of Columbia (D.C.) ban driving while talking on a handheld cell phone. Long-term effects on driver handheld phone use in D.C., New York State, and Connecticut were examined. The percentage of drivers talking on handheld cell phones was measured over time with daytime observation surveys in the jurisdictions with bans and comparison jurisdictions without bans. Trends were modeled using Poisson regression to estimate differences between actual rates and rates that would have been expected without a ban. The D.C. ban immediately lowered the percentage of drivers talking on handheld cell phones by 41 percent. Nearly 5 years later, the rate was 43 percent lower than would have been expected without the ban. Use in Connecticut declined 76 percent immediately after the ban; 3.5 years later, use was 65 percent lower than would have been expected without the ban. In New York, use declined 47 percent immediately after the ban; 7 years later, use was 24 percent lower than expected without the ban. Fifteen months after the laws took effect, compliance in New York was lower than in D.C., and the difference appeared due to more intensive enforcement in D.C. However, this linkage is no longer clear because enforcement in New York picked up such that 2008 levels of enforcement appeared comparable in D.C. and New York, whereas enforcement in Connecticut lagged behind. In all three jurisdictions, the chance that a violator would receive a citation was low, and there were no publicized targeted enforcement campaigns. Jurisdictional bans have reduced handheld phone use and appear capable of maintaining reductions for the long term. However, it is unknown whether overall phone use is lower because many drivers may have switched to hands-free devices. Further research is needed to determine whether reduced handheld cell phone use has reduced crashes.

Mobile applications for handheld devices to screen and randomize acute stroke patients in clinical trials.

PubMed

Qureshi, Ai; Connelly, B; Abbott, Ei; Maland, E; Kim, J; Blake, J

2012-08-01

The availability of internet connectivity and mobile application software used by low-power handheld devices makes smart phones of unique value in time-sensitive clinical trials. Trial-specific applications can be downloaded by investigators from various mobile software distribution platforms or web applications delivered over HTTP. The Antihypertensive Treatment in Acute Cerebral Hemorrhage (ATACH) II investigators in collaboration with MentorMate released the ATACH-II Patient Recruitment mobile application available on iPhone, Android, and Blackberry in 2011. The mobile application provides tools for pre-screening, assessment of eligibility, and randomization of patients. Since the release of ATACH-II mobile application, the CLEAR-IVH (Clot Lysis Evaluating Accelerated Resolution of Intraventricular Hemorrhage) trial investigators have also adopted such a mobile application. The video-conferencing capabilities of the most recent mobile devices open up additional opportunities to involve central coordinating centers in the recruitment process in real time.

The Rosetta phone: a hand-held device for automatic translation of signs in natural images

NASA Astrophysics Data System (ADS)

Jafri, Syed Ali Raza; Mikkilineni, Aravind K.; Boutin, Mireille; Delp, Edward J.

2008-02-01

When traveling in a region where the local language is not written using the Roman alphabet, translating written text (e.g., documents, road signs, or placards) is a particularly difficult problem since the text cannot be easily entered into a translation device or searched using a dictionary. To address this problem, we are developing the "Rosetta Phone," a handheld device (e.g., PDA or mobile telephone) capable of acquiring a picture of the text, identifying the text within the image, and producing both an audible and a visual English interpretation of the text. We started with English, as a developement language, for which we achieved close to 100% accuracy in identifying and reading text. We then modified the system to be able to read and translate words written using the Arabic character set. We currently achieve approximately 95% accuracy in reading words from a small directory of town names.

Bone age maturity assessment using hand-held device

NASA Astrophysics Data System (ADS)

Ratib, Osman M.; Gilsanz, Vicente; Liu, Xiaodong; Boechat, M. I.

2004-04-01

Purpose: Assessment of bone maturity is traditionally performed through visual comparison of hand and wrist radiograph with existing reference images in textbooks. Our goal was to develop a digital index based on idealized hand Xray images that can be incorporated in a hand held computer and used for visual assessment of bone age for patients. Material and methods: Due to the large variability in bone maturation in normals, we generated a set of "ideal" images obtained by computer combinations of images from our normal reference data sets. Software for hand-held PDA devices was developed for easy navigation through the set of images and visual selection of matching images. A formula based on our statistical analysis provides the standard deviation from normal based on the chronological age of the patient. The accuracy of the program was compared to traditional interpretation by two radiologists in a double blind reading of 200 normal Caucasian children (100 boys, 100 girls). Results: Strong correlations were present between chronological age and bone age (r > 0.9) with no statistical difference between the digital and traditional assessment methods. Determinations of carpal bone maturity in adolescents was slightly more accurate using the digital system. The users did praise the convenience and effectiveness of the digital Palm Index in clinical practice. Conclusion: An idealized digital Palm Bone Age Index provides a convenient and effective alternative to conventional atlases for the assessment of skeletal maturity.

A new approach for the screening of carotid lesions: a 'fast-track' method with the use of new generation hand-held ultrasound devices.

PubMed

Aboyans, V; Lacroix, P; Jeannicot, A; Guilloux, J; Bertin, F; Laskar, M

2004-09-01

We assessed the usefulness of fast-track neck sonography with a new-generation hand-held ultrasound scanner in the detection of > or =60% carotid stenosis. Patients with a past history of atherosclerotic disease or presence of risk factors were enrolled. All had fast-track carotid screening with a hand-held ultrasound scanner. Initial assessment was performed with our quick imaging protocol. A second examiner performed a conventional complete carotid duplex as gold-standard. We enrolled 197 consecutive patients with a mean age of 67 years (range 35-94). A carotid stenosis >60% was detected in 13 cases (6%). The sensitivity, specificity, positive and negative predictive value of fast-track sonography was 100%, 64%, 17% and 100%, respectively. Concomitant power Doppler imaging during the fast-track method did not improve accuracy. The use of a fast-track method with a hand-held ultrasound device can reduce the number of unnecessary carotid Duplex and enhance the screening efficiency without missing significant carotid stenoses.

Feasibility of a novel remote daily monitoring system for age-related macular degeneration using mobile handheld devices: results of a pilot study.

PubMed

Kaiser, Peter K; Wang, Yi-Zhong; He, Yu-Guang; Weisberger, Annemarie; Wolf, Stephane; Smith, Craig H

2013-10-01

This pilot study evaluated the feasibility of the Health Management Tool (HMT), a novel computing system using mobile handheld devices, to remotely monitor retinal visual function daily in patients with neovascular age-related macular degeneration treated with ranibizumab. Patients with neovascular age-related macular degeneration in at least 1 eye (newly diagnosed or successfully treated < 1 year) and eligible for ranibizumab therapy were enrolled in this 16-week, prospective, open-label, single-arm study. Patients performed a shape discrimination hyperacuity test (myVisionTrack [mVT]) daily on the HMT device (iPhone 3GS) remotely and at all clinic visits. Data entered into HMT devices were collected in the HMT database, which also sent reminders for patients to take mVT. Among 160 patients from 24 U.S. centers enrolled in the study (103 [64%] ≥ 75 years of age), 84.7% on average complied with daily mVT testing and ≈ 98.9% complied with at least weekly mVT testing. The HMT database successfully uploaded more than 17,000 mVT assessment values and sent more than 9,000 reminders. Elderly patients with neovascular age-related macular degeneration were willing and able to comply with daily self-testing of retinal visual function using mobile handheld devices in this novel system of remote vision monitoring.

Dental optical coherence domain reflectometry explorer

DOEpatents

Everett, Matthew J.; Colston, Jr., Billy W.; Sathyam, Ujwal S.; Da Silva, Luiz B.

2001-01-01

A hand-held, fiber optic based dental device with optical coherence domain reflectometry (OCDR) sensing capabilities provides a profile of optical scattering as a function of depth in the tissue at the point where the tip of the dental explorer touches the tissue. This system provides information on the internal structure of the dental tissue, which is then used to detect caries and periodontal disease. A series of profiles of optical scattering or tissue microstructure are generated by moving the explorer across the tooth or other tissue. The profiles are combined to form a cross-sectional, or optical coherence tomography (OCT), image.

Fiber optic monitoring device

DOEpatents

Samborsky, James K.

1993-01-01

A device for the purpose of monitoring light transmissions in optical fibers comprises a fiber optic tap that optically diverts a fraction of a transmitted optical signal without disrupting the integrity of the signal. The diverted signal is carried, preferably by the fiber optic tap, to a lens or lens system that disperses the light over a solid angle that facilitates viewing. The dispersed light indicates whether or not the monitored optical fiber or system of optical fibers is currently transmitting optical information.

Neurosurgical sapphire handheld probe for intraoperative optical diagnostics, laser coagulation and aspiration of malignant brain tissue

NASA Astrophysics Data System (ADS)

Shikunova, Irina A.; Zaytsev, Kirill I.; Stryukov, Dmitrii O.; Dubyanskaya, Evgenia N.; Kurlov, Vladimir N.

2017-07-01

In this paper, a handheld contact probe based on sapphire shaped crystal was developed for the intraoperative optical diagnosis and aspiration of malignant brain tissue combined with the laser hemostasis. Such a favorable combination of several functions in a single instrument significantly increases its clinical relevance. It makes possible highly-accurate real-time detection and removal of either large-scale malignancies or even separate invasive cancer cells. The proposed neuroprobe was integrated into the clinical neurosurgical workflow for the intraoperative fluorescence identification and removal of malignant tissues of the brain.

Portable control device for networked mobile robots

DOEpatents

Feddema, John T.; Byrne, Raymond H.; Bryan, Jon R.; Harrington, John J.; Gladwell, T. Scott

2002-01-01

A handheld control device provides a way for controlling one or multiple mobile robotic vehicles by incorporating a handheld computer with a radio board. The device and software use a personal data organizer as the handheld computer with an additional microprocessor and communication device on a radio board for use in controlling one robot or multiple networked robots.

Hand-held Raman sensor head for in-situ characterization of meat quality applying a microsystem 671 nm diode laser

NASA Astrophysics Data System (ADS)

Schmidt, Heinar; Sowoidnich, Kay; Maiwald, Martin; Sumpf, Bernd; Kronfeldt, Heinz-Detlef

2009-05-01

A hand-held Raman sensor head was developed for the in-situ characterization of meat quality. As light source, a microsystem based external cavity diode laser module (ECDL) emitting at 671 nm was integrated in the sensor head and attached to a miniaturized optical bench which contains lens optics for excitation and signal collection as well as a Raman filter stage for Rayleigh rejection. The signal is transported with an optical fiber to the detection unit which was in the initial phase a laboratory spectrometer with CCD detector. All elements of the ECDL are aligned on a micro optical bench with 13 x 4 mm2 footprint. The wavelength stability is provided by a reflection Bragg grating and the laser has an optical power of up to 200 mW. However, for the Raman measurements of meat only 35 mW are needed to obtain Raman spectra within 1 - 5 seconds. Short measuring times are essential for the hand-held device. The laser and the sensor head are characterized in terms of stability and performance for in-situ Raman investigations. The function is demonstrated in a series of measurements with raw and packaged pork meat as samples. The suitability of the Raman sensor head for the quality control of meat and other products will be discussed.

Space Qualification Issues in Acousto-optic and Electro-optic Devices

NASA Technical Reports Server (NTRS)

Prasad, Narasimha S.; Taylor, Edward W.; Trivedi, Sudhir; Kutcher, Sue; Soos, Jolanta

2007-01-01

Satellite and space-based applications of photonic devices and systems require operational reliability in the harsh environment of space for extended periods of time. This in turn requires every component of the systems and their packaging to meet space qualifications. Acousto- and electro-optical devices form the major components of many current space based optical systems, which is the focus of this paper. The major space qualification issues are related to: mechanical stability, thermal effects and operation of the devices in the naturally occurring space radiation environment. This paper will discuss acousto- and electro-optic materials and devices with respect to their stability against mechanical vibrations, thermal cycling in operating and non-operating conditions and device responses to space ionizing and displacement radiation effects. Selection of suitable materials and packaging to meet space qualification criteria will also be discussed. Finally, a general roadmap for production and testing of acousto- and electro-optic devices will be discussed.

True color scanning laser ophthalmoscopy and optical coherence tomography handheld probe

PubMed Central

LaRocca, Francesco; Nankivil, Derek; Farsiu, Sina; Izatt, Joseph A.

2014-01-01

Scanning laser ophthalmoscopes (SLOs) are able to achieve superior contrast and axial sectioning capability compared to fundus photography. However, SLOs typically use monochromatic illumination and are thus unable to extract color information of the retina. Previous color SLO imaging techniques utilized multiple lasers or narrow band sources for illumination, which allowed for multiple color but not “true color” imaging as done in fundus photography. We describe the first “true color” SLO, handheld color SLO, and combined color SLO integrated with a spectral domain optical coherence tomography (OCT) system. To achieve accurate color imaging, the SLO was calibrated with a color test target and utilized an achromatizing lens when imaging the retina to correct for the eye’s longitudinal chromatic aberration. Color SLO and OCT images from volunteers were then acquired simultaneously with a combined power under the ANSI limit. Images from this system were then compared with those from commercially available SLOs featuring multiple narrow-band color imaging. PMID:25401032

Prevalence and risk factors associated with musculoskeletal complaints among users of mobile handheld devices: A systematic review.

PubMed

Xie, Yanfei; Szeto, Grace; Dai, Jie

2017-03-01

This systematic review aimed at evaluating the prevalence and risk factors for musculoskeletal complaints associated with mobile handheld device use. Pubmed, Medline, Web of Science, CINAHL and Embase were searched. The methodological quality of included studies was assessed. Strength of evidence for risk factors was determined based on study designs, methodological quality and consistency of results. Five high-quality, eight acceptable-quality and two low-quality peer-reviewed articles were included. This review demonstrates that the prevalence of musculoskeletal complaints among mobile device users ranges from 1.0% to 67.8% and neck complaints have the highest prevalence rates ranging from 17.3% to 67.8%. This study also finds some evidence for neck flexion, frequency of phone calls, texting and gaming in relation to musculoskeletal complaints among mobile device users. Inconclusive evidence is shown for other risk factors such as duration of use and human-device interaction techniques due to inconsistent results or a limited number of studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optically detonated explosive device

NASA Technical Reports Server (NTRS)

Yang, L. C.; Menichelli, V. J. (Inventor)

1974-01-01

A technique and apparatus for optically detonating insensitive high explosives, is disclosed. An explosive device is formed by containing high explosive material in a house having a transparent window. A thin metallic film is provided on the interior surface of the window and maintained in contact with the high explosive. A laser pulse provided by a Q-switched laser is focussed on the window to vaporize the metallic film and thereby create a shock wave which detonates the high explosive. Explosive devices may be concurrently or sequentially detonated by employing a fiber optic bundle to transmit the laser pulse to each of the several individual explosive devices.

Optical devices: A compilation

NASA Technical Reports Server (NTRS)

1976-01-01

Technological developments in the field of optics devices which have potential utility outside the aerospace community are described. Optical instrumentation, light generation and transmission, and laser techniques are among the topics covered. Patent information is given.

Optical processing for semiconductor device fabrication

NASA Technical Reports Server (NTRS)

Sopori, Bhushan L.

1994-01-01

A new technique for semiconductor device processing is described that uses optical energy to produce local heating/melting in the vicinity of a preselected interface of the device. This process, called optical processing, invokes assistance of photons to enhance interface reactions such as diffusion and melting, as compared to the use of thermal heating alone. Optical processing is performed in a 'cold wall' furnace, and requires considerably lower energies than furnace or rapid thermal annealing. This technique can produce some device structures with unique properties that cannot be produced by conventional thermal processing. Some applications of optical processing involving semiconductor-metal interfaces are described.

Electro-optic device with gap-coupled electrode

DOEpatents

Deri, Robert J.; Rhodes, Mark A.; Bayramian, Andrew J.; Caird, John A.; Henesian, Mark A.; Ebbers, Christopher A.

2013-08-20

An electro-optic device includes an electro-optic crystal having a predetermined thickness, a first face and a second face. The electro-optic device also includes a first electrode substrate disposed opposing the first face. The first electrode substrate includes a first substrate material having a first thickness and a first electrode coating coupled to the first substrate material. The electro-optic device further includes a second electrode substrate disposed opposing the second face. The second electrode substrate includes a second substrate material having a second thickness and a second electrode coating coupled to the second substrate material. The electro-optic device additionally includes a voltage source electrically coupled to the first electrode coating and the second electrode coating.

Handheld Computers in Education: An Industry Perspective

ERIC Educational Resources Information Center

van 't Hooft, Mark; Vahey, Philip

2007-01-01

Five representatives from the mobile computing industry provide their perspectives on handhelds in education. While some of their ideas differ, they all agree on the importance of staff development, appropriate curriculum development, and teacher support to create the kinds of personalized learning environments that mobile devices make possible.

Materials requirements for optical processing and computing devices

NASA Technical Reports Server (NTRS)

Tanguay, A. R., Jr.

1985-01-01

Devices for optical processing and computing systems are discussed, with emphasis on the materials requirements imposed by functional constraints. Generalized optical processing and computing systems are described in order to identify principal categories of requisite components for complete system implementation. Three principal device categories are selected for analysis in some detail: spatial light modulators, volume holographic optical elements, and bistable optical devices. The implications for optical processing and computing systems of the materials requirements identified for these device categories are described, and directions for future research are proposed.

Field-programmable logic devices with optical input-output.

PubMed

Szymanski, T H; Saint-Laurent, M; Tyan, V; Au, A; Supmonchai, B

2000-02-10

A field-programmable logic device (FPLD) with optical I/O is described. FPLD's with optical I/O can have their functionality specified in the field by means of downloading a control-bit stream and can be used in a wide range of applications, such as optical signal processing, optical image processing, and optical interconnects. Our device implements six state-of-the-art dynamically programmable logic arrays (PLA's) on a 2 mm x 2 mm die. The devices were fabricated through the Lucent Technologies-Advanced Research Projects Agency-Consortium for Optical and Optoelectronic Technologies in Computing (Lucent/ARPA/COOP) workshop by use of 0.5-microm complementary metal-oxide semiconductor-self-electro-optic device technology and were delivered in 1998. All devices are fully functional: The electronic data paths have been verified at 200 MHz, and optical tests are pending. The device has been programmed to implement a two-stage optical switching network with six 4 x 4 crossbar switches, which can realize more than 190 x 10(6) unique programmable input-output permutations. The same device scaled to a 2 cm x 2 cm substrate could support as many as 4000 optical I/O and 1 Tbit/s of optical I/O bandwidth and offer fully programmable digital functionality with approximately 110,000 programmable logic gates. The proposed optoelectronic FPLD is also ideally suited to realizing dense, statically reconfigurable crossbar switches. We describe an attractive application area for such devices: a rearrangeable three-stage optical switch for a wide-area-network backbone, switching 1000 traffic streams at the OC-48 data rate and supporting several terabits of traffic.

Noninvasive structural and microvascular anatomy of oral mucosae using handheld optical coherence tomography

PubMed Central

Tsai, Meng-Tsan; Chen, Yingdan; Lee, Cheng-Yu; Huang, Bo-Huei; Trung, Nguyen Hoang; Lee, Ya-Ju; Wang, Yen-Li

2017-01-01

In this study, we demonstrated the feasibility of using a handheld optical coherence tomography (OCT) for in vivo visualizations of the microstructural and microvascular features of various oral mucosal types. To scan arbitrary locations of the oral mucosa, a scanning probe was developed, composed of a probe body fabricated by a 3D printer, miniaturized two-axis galvanometer, relay lenses, and reflective prism. With a 3D printing technique, the probe weight and the system volume were greatly reduced, enabling the effective improvement of imaging artifacts from unconscious motion and system complexity. Additionally, in our design, the distal end of the probe can be switched to fit various oral conditions, and the optical parameters of the probe, such as the transverse resolution, working distance, and probe length can be easily varied. The results showed that the epithelium and lamina propria layers, as well as the fungiform papilla and salivary gland, were differentiated. Moreover, various microcirculation features at different mucosal sites were identified that are potentially effective indicators for the diagnosis of premalignant lesions. The demonstrated results indicate that the developed OCT system is a promising tool for noninvasive imaging of oral mucosae. PMID:29188097

Hand Held Device for Wireless Powering and Interrogation of Biomems Sensors and Actuators

NASA Technical Reports Server (NTRS)

Simons, Rainee N (Inventor); Miranda, Felix Antonio (Inventor)

2007-01-01

A compact, hand-held device for wireless powering, interrogation and data retrieval from at least one implanted sensor. The hand-held device includes an antenna for powering an implanted sensor and for receiving data from the implanted sensor to the hand-held device for at least one of storage, display or analysis. The hand-held device establishes electromagnetic coupling with a low radiating radio frequency power inductor in the implanted sensor at a predefined separation and the antenna geometry allows for the antenna to power, interrogate and retrieve data from the implanted sensor without strapping the hand-held device to a human body housing the implanted sensor The hand-held device optionally allows for activation of the implanted sensor only during interrogation and data retrieval.

Resonant optical device with a microheater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lentine, Anthony L.; DeRose, Christopher

2017-04-04

A resonant photonic device is provided. The device comprises an optical waveguiding element, such as an optical resonator, that includes a diode junction region, two signal terminals configured to apply a bias voltage across the junction region, and a heater laterally separated from the optical waveguiding element. A semiconductor electrical barrier element is juxtaposed to the heater. A metallic strip is electrically and thermally connected at one end to a signal terminal of the optical waveguiding element and thermally connected at another end to the barrier element.

Handheld detector using NIR for bottled liquid explosives

NASA Astrophysics Data System (ADS)

Itozaki, Hideo; Sato-Akaba, Hideo

2014-10-01

A handheld bottle checker for detection of liquid explosives is developed using near infrared technology. In order to make it compact, a LED light was used as a light source and a novel circuit board was developed for the device control instead of using a PC. This enables low power consumption and this handheld detector can be powered by a Li-ion battery without an AC power supply. This checker works well to analyze liquids, even using limited bandwidth of NIR by the LED. It is expected that it can be applied not only to airport security but also to wider applications because of its compactness and portability.

Is it Time to Replace Physical Examination with a Hand-Held Ultrasound Device?

PubMed Central

Kaul, Sanjiv

2014-01-01

Attempts at using physical examination (PE) go back centuries, with inspection, palpation, and percussion being the mainstay of this approach until 2 centuries ago when the stethoscope was invented and auscultation became probably the most important element of PE for patients with known or suspected cardiovascular disease (CVD). Despite its several limitations, PE is still used, sometimes as the only means, of evaluating and following patients with CVD. In this paper I shall argue for the substitution of this inaccurate and archaic approach by direct visualization of the heart using a hand-held ultrasound (HHU) device. I am not in any way suggesting the substitution of a comprehensive echocardiographic examination by an expert sonographer/echocardiographer by HHU in patients with significant CVD. Instead, I am arguing for the replacement of PE for evaluation of the heart at the point of care as well as at the bedside, simply because HHU is more accurate and provides more meaningful information. PMID:28465916

Is it Time to Replace Physical Examination with a Hand-Held Ultrasound Device?

PubMed

Kaul, Sanjiv

2014-01-01

Attempts at using physical examination (PE) go back centuries, with inspection, palpation, and percussion being the mainstay of this approach until 2 centuries ago when the stethoscope was invented and auscultation became probably the most important element of PE for patients with known or suspected cardiovascular disease (CVD). Despite its several limitations, PE is still used, sometimes as the only means, of evaluating and following patients with CVD. In this paper I shall argue for the substitution of this inaccurate and archaic approach by direct visualization of the heart using a hand-held ultrasound (HHU) device. I am not in any way suggesting the substitution of a comprehensive echocardiographic examination by an expert sonographer/echocardiographer by HHU in patients with significant CVD. Instead, I am arguing for the replacement of PE for evaluation of the heart at the point of care as well as at the bedside, simply because HHU is more accurate and provides more meaningful information.

Portable handheld diffuse reflectance spectroscopy system for clinical evaluation of skin: a pilot study in psoriasis patients

PubMed Central

Tzeng, Shih-Yu; Guo, Jean-Yan; Yang, Chao-Chun; Hsu, Chao-Kai; Huang, Hung Ji; Chou, Shih-Jie; Hwang, Chi-Hung; Tseng, Sheng-Hao

2016-01-01

Diffuse reflectance spectroscopy (DRS) has been utilized to study biological tissues for a variety of applications. However, many DRS systems are not designed for handheld use and/or relatively expensive which limit the extensive clinical use of this technique. In this paper, we report a handheld, low-cost DRS system consisting of a light source, optical switch, and a spectrometer, that can precisely quantify the optical properties of tissue samples in the clinical setting. The handheld DRS system was employed to determine the skin chromophore concentrations, absorption and scattering properties of 11 patients with psoriasis. The measurement results were compared to the clinical severity of psoriasis as evaluated by dermatologist using PASI (Psoriasis Area and Severity Index) scores. Our statistical analyses indicated that the handheld DRS system could be a useful non-invasive tool for objective evaluation of the severity of psoriasis. It is expected that the handheld system can be used for the objective evaluation and monitoring of various skin diseases such as keloid and psoriasis. PMID:26977366

Feasibility of using a handheld electronic device for the collection of patient reported outcomes data from children.

PubMed

Vinney, Lisa A; Grade, John D; Connor, Nadine P

2012-01-01

The manner in which a communication disorder affects health-related quality of life (QOL) in children is not known. Unfortunately, collection of quality of life data via traditional paper measures is labor intensive and has several other limitations, which hinder the investigation of pediatric quality of life in children. Currently, there is not sufficient research regarding the use of electronic devices to collect pediatric patient reported outcomes in order to address such limitations. Thus, we used a cross-over design to compare responses to a pediatric health quality of life instrument (PedsQL 4.0) delivered using a handheld electronic device to those from a traditional paper form. Respondents were children with (n=9) and without (n=10) a speech or voice disorder. For paper versus the electronic format, we examined time to completion, number of incomplete or inaccurate question responses, intra-rater reliability, ease of use, and child and parent preference. There were no significant differences between children's scores, time to complete the measure, or ratings related to ease of answering questions. The percentage of children who made answering errors or omissions with paper and pencil was significantly greater than the percentage of children who made such errors using the device. This preliminary study demonstrated that use of an electronic device to collect QOL or patient-reported outcomes (PRO) data from children is more efficient than and just as feasible, reliable, and acceptable as using paper forms. The development of hardware and software applications for the collection of QOL and/or PRO data in children with speech disorders is likely warranted. The reader will be able to understand: (1) The potential benefits of using electronic data capture via handheld devices for collecting pediatric patient reported outcomes; (2) The Pediatric Quality of Life Inventory 4.0 is a measure of the perception of general health quality that has distinguished between

Multimodal ophthalmic imaging using handheld spectrally encoded coherence tomography and reflectometry (SECTR)

NASA Astrophysics Data System (ADS)

Leeburg, Kelsey C.; El-Haddad, Mohamed T.; Malone, Joseph D.; Terrones, Benjamin D.; Tao, Yuankai K.

2018-02-01

Scanning laser ophthalmoscopy (SLO) provides high-speed, noninvasive en face imaging of the retinal fundus. Optical coherence tomography (OCT) is the current "gold-standard" for ophthalmic diagnostic imaging and enables depth-resolved visualization of ophthalmic structures and image-based surrogate biomarkers of disease. We present a compact optical and mechanical design for handheld spectrally encoded coherence tomography and reflectometry (SECTR) for multimodality en face spectrally encoded reflectometry (SER) and cross-sectional OCT imaging. We custom-designed a double-pass telecentric scan lens, which halves the size of 4-f optical relays and allowed us to reduce the footprint of our SECTR scan-head by a factor of >2.7x (volume) over our previous design. The double-pass scan lens was optimized for diffraction-limited performance over a +/-10° scan field. SECTR optics and optomechanics were combined in a compact rapid-prototyped enclosure with dimensions 87 x 141.8 x 137 mm (w x h x d). SECTR was implemented using a custom-built 400 kHz 1050 nm swept-source. OCT and SER were simultaneously digitized on dual input channels of a 4 GS/s digitizer at 1.4 GS/s per channel. In vivo human en face SER and cross-sectional OCT images were acquired at 350 fps. OCT volumes of 1000 B-scans were acquired in 2.86 s. We believe clinical translation of our compact handheld design will benefit point-of-care ophthalmic diagnostics in patients who are unable to be imaged on conventional slit-lamp based systems, such as infants and the bedridden. When combined with multi-volumetric registration methods, handheld SECTR will have advantages in motion-artifact free imaging over existing handheld technologies.

Thin, nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth (Inventor); Hughes, Eli (Inventor)

2008-01-01

A thin, nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Thin, nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth (Inventor); Hughes, Eli (Inventor)

2007-01-01

A thin, nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Thin nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth J. (Inventor); Hughes, Eli (Inventor)

2009-01-01

A thin nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Optical-microwave interactions in semiconductor devices

NASA Astrophysics Data System (ADS)

Figueroa, L.; Slayman, C.; Yen, H. W.

1980-02-01

GaAs FETs with built-in optical waveguides are being developed. The purpose is to allow optical signals to be coupled into the active region of the devices efficiently. These FETs will be useful for optical mixing, optical injection locking, and optical detection purposes.

Characterization of ultrafast devices using novel optical techniques

NASA Astrophysics Data System (ADS)

Ali, Md Ershad

Optical techniques have been extensively used to examine the high frequency performance of a number of devices including High Electron Mobility Transistors (HEMTs), Heterojunction Bipolar Phototransistors (HPTs) and Low Temperature GaAs (LT-GaAs) Photoconductive Switches. To characterize devices, frequency and time domain techniques, namely optical heterodyning and electro-optic sampling, having measurement bandwidths in excess of 200 GHz, were employed. Optical mixing in three-terminal devices has been extended for the first time to submillimeter wave frequencies. Using a new generation of 50-nm gate pseudomorphic InP-based HEMTs, optically mixed signals were detected to 552 GHz with a signal-to-noise ratio of approximately 5 dB. To the best of our knowledge, this is the highest frequency optical mixing obtained in three- terminal devices to date. A novel harmonic three-wave detection scheme was used for the detection of the optically generated signals. The technique involved downconversion of the signal in the device by the second harmonic of a gate-injected millimeter wave local oscillator. Measurements were also conducted up to 212 GHz using direct optical mixing and up to 382 GHz using a fundamental three-wave detection scheme. New interesting features in the bias dependence of the optically mixed signals have been reported. An exciting novel development from this work is the successful integration of near-field optics with optical heterodyning. The technique, called near-field optical heterodyning (NFOH), allows for extremely localized injection of high-frequency stimulus to any arbitrary point of an ultrafast device or circuit. Scanning the point of injection across the sample provides details of the high frequency operation of the device with high spatial resolution. For the implementation of the technique, fiber-optic probes with 100 nm apertures were fabricated. A feedback controlled positioning system was built for accurate placement and scanning of the

Method And Apparatus For Coupling Optical Elements To Optoelectronic Devices For Manufacturing Optical Transceiver Modules

DOEpatents

Anderson, Gene R.; Armendariz, Marcelino G.; Bryan, Robert P.; Carson, Richard F.; Chu, Dahwey; Duckett, III, Edwin B.; Giunta, Rachel Knudsen; Mitchell, Robert T.; McCormick, Frederick B.; Peterson, David W.; Rising, Merideth A.; Reber, Cathleen A.; Reysen, Bill H.

2005-06-14

A process is provided for aligning and connecting at least one optical fiber to at least one optoelectronic device so as to couple light between at least one optical fiber and at least one optoelectronic device. One embodiment of this process comprises the following steps: (1) holding at least one optical element close to at least one optoelectronic device, at least one optical element having at least a first end; (2) aligning at least one optical element with at least one optoelectronic device; (3) depositing a first non-opaque material on a first end of at least one optoelectronic device; and (4) bringing the first end of at least one optical element proximate to the first end of at least one optoelectronic device in such a manner that the first non-opaque material contacts the first end of at least one optoelectronic device and the first end of at least one optical element. The optical element may be an optical fiber, and the optoelectronic device may be a vertical cavity surface emitting laser. The first non-opaque material may be a UV optical adhesive that provides an optical path and mechanical stability. In another embodiment of the alignment process, the first end of at least one optical element is brought proximate to the first end of at least one optoelectronic device in such a manner that an interstitial space exists between the first end of at least one optoelectronic device and the first end of at least one optical element.

Neurosurgery contact handheld probe based on sapphire shaped crystal

NASA Astrophysics Data System (ADS)

Shikunova, I. A.; Stryukov, D. O.; Rossolenko, S. N.; Kiselev, A. M.; Kurlov, V. N.

2017-01-01

A handheld contact probe based on sapphire shaped crystal is developed for intraoperative spectrally-resolved optical diagnostics, laser coagulation and aspiration of malignant brain tissue. The technology was integrated into the neurosurgical workflow for intraoperative real-time identification and removing of invasive brain cancer.

Trends in Handheld Computing Among Medical Students

PubMed Central

Grasso, Michael A.; Yen, M. Jim; Mintz, Matthew L.

2005-01-01

The purpose of this study was to identify trends in the utilization and acceptance of handheld computers (personal digital assistants) among medical students during preclinical and clinical training. These results can be used to identify differences between preclinical and clinical users, differences between current use and idealized use, and perceived limitations of these devices. PMID:16779255

PROSPECTIVE EVALUATION OF VISUAL ACUITY AGREEMENT BETWEEN STANDARD EARLY TREATMENT DIABETIC RETINOPATHY STUDY CHART AND A HANDHELD EQUIVALENT IN EYES WITH RETINAL PATHOLOGY.

PubMed

Rahimy, Ehsan; Reddy, Sahitya; DeCroos, Francis Char; Khan, M Ali; Boyer, David S; Gupta, Omesh P; Regillo, Carl D; Haller, Julia A

2015-08-01

To evaluate the visual acuity agreement between a standard back-illuminated Early Treatment Diabetic Retinopathy Study (ETDRS) chart and a handheld internally illuminated ETDRS chart. Two-center prospective study. Seventy patients (134 eyes) with retinal pathology were enrolled between October 2012 and August 2013. Visual acuity was measured using both the ETDRS chart and the handheld device by masked independent examiners after best protocol refraction. Examination was performed in the same room under identical illumination and testing conditions. The mean number of letters seen was 63.0 (standard deviation: 19.8 letters) and 61.2 letters (standard deviation: 19.1 letters) for the ETDRS chart and handheld device, respectively. Mean difference per eye between the ETDRS and handheld device was 1.8 letters. A correlation coefficient (r) of 0.95 demonstrated a positive linear correlation between ETDRS chart and handheld device measured acuities. Intraclass correlation coefficient was performed to assess the reproducibility of the measurements made by different observers measuring the same quantity and was calculated to be 0.95 (95% confidence interval: 0.93-0.96). Agreement was independent of retinal disease. The strong correlation between measured visual acuity using the ETDRS and handheld equivalent suggests that they may be used interchangeably, with accurate measurements. Potential benefits of this device include convenience and portability, as well as the ability to assess ETDRS visual acuity without a dedicated testing lane.

Tapered rib fiber coupler for semiconductor optical devices

DOEpatents

Vawter, Gregory A.; Smith, Robert Edward

2001-01-01

A monolithic tapered rib waveguide for transformation of the spot size of light between a semiconductor optical device and an optical fiber or from the fiber into the optical device. The tapered rib waveguide is integrated into the guiding rib atop a cutoff mesa type semiconductor device such as an expanded mode optical modulator or and expanded mode laser. The tapered rib acts to force the guided light down into the mesa structure of the semiconductor optical device instead of being bound to the interface between the bottom of the guiding rib and the top of the cutoff mesa. The single mode light leaving or entering the output face of the mesa structure then can couple to the optical fiber at coupling losses of 1.0 dB or less.

Handheld Chem/Biosensor Using Extreme Conformational Changes in Designed Binding Proteins to Enhance Surface Plasmon Resonance (SPR)

DTIC Science & Technology

2016-04-01

AFCEC-CX-TY-TR-2016-0007 HANDHELD CHEM/ BIOSENSOR USING EXTREME CONFORMATIONAL CHANGES IN DESIGNED BINDING PROTEINS TO ENHANCE SURFACE PLASMON...Include area code) 03/24/2016 Abstract 08/14/2015--03/31/2016 Handheld chem/ biosensor using extreme conformational changes in designed binding...Baltimore, Maryland on 17-21 April 2016. We propose the development of a highly sensitive handheld chem/ biosensor device using a novel class of engineered

Neuroradiology Using Secure Mobile Device Review.

PubMed

Randhawa, Privia A; Morrish, William; Lysack, John T; Hu, William; Goyal, Mayank; Hill, Michael D

2016-04-05

Image review on computer-based workstations has made film-based review outdated. Despite advances in technology, the lack of portability of digital workstations creates an inherent disadvantage. As such, we sought to determine if the quality of image review on a handheld device is adequate for routine clinical use. Six CT/CTA cases and six MR/MRA cases were independently reviewed by three neuroradiologists in varying environments: high and low ambient light using a handheld device and on a traditional imaging workstation in ideal conditions. On first review (using a handheld device in high ambient light), a preliminary diagnosis for each case was made. Upon changes in review conditions, neuroradiologists were asked if any additional features were seen that changed their initial diagnoses. Reviewers were also asked to comment on overall clinical quality and if the handheld display was of acceptable quality for image review. After the initial CT review in high ambient light, additional findings were reported in 2 of 18 instances on subsequent reviews. Similarly, additional findings were identified in 4 of 18 instances after the initial MR review in high ambient lighting. Only one of these six additional findings contributed to the diagnosis made on the initial preliminary review. Use of a handheld device for image review is of adequate diagnostic quality based on image contrast, sharpness of structures, visible artefacts and overall display quality. Although reviewers were comfortable with using this technology, a handheld device with a larger screen may be diagnostically superior.

Handheld spectrometers: the state of the art

NASA Astrophysics Data System (ADS)

Crocombe, Richard A.

2013-05-01

"Small" spectrometers fall into three broad classes: small versions of laboratory instruments, providing data, subsequently processed on a PC; dedicated analyzers, providing actionable information to an individual operator; and process analyzers, providing quantitative or semi-quantitative information to a process controller. The emphasis of this paper is on handheld dedicated analyzers. Many spectrometers have historically been large, possible fragile, expensive and complicated to use. The challenge over the last dozen years, as instruments have moved into the field, has been to make spectrometers smaller, affordable, rugged, easy-to-use, but most of all capable of delivering actionable results. Actionable results can dramatically improve the efficiency of a testing process and transform the way business is done. There are several keys to this handheld spectrometer revolution. Consumer electronics has given us powerful mobile platforms, compact batteries, clearly visible displays, new user interfaces, etc., while telecomm has revolutionized miniature optics, sources and detectors. While these technologies enable miniature spectrometers themselves, actionable information has demanded the development of rugged algorithms for material confirmation, unknown identification, mixture analysis and detection of suspicious materials in unknown matrices. These algorithms are far more sophisticated than the `correlation' or `dot-product' methods commonly used in benchtop instruments. Finally, continuing consumer electronics advances now enable many more technologies to be incorporated into handheld spectrometers, including Bluetooth, wireless, WiFi, GPS, cameras and bar code readers, and the continued size shrinkage of spectrometer `engines' leads to the prospect of dual technology or `hyphenated' handheld instruments.

Handheld vs. laptop computers for electronic data collection in clinical research: a crossover randomized trial.

PubMed

Haller, Guy; Haller, Dagmar M; Courvoisier, Delphine S; Lovis, Christian

2009-01-01

To compare users' speed, number of entry errors and satisfaction in using two current devices for electronic data collection in clinical research: handheld and laptop computers. The authors performed a randomized cross-over trial using 160 different paper-based questionnaires and representing altogether 45,440 variables. Four data coders were instructed to record, according to a random predefined and equally balanced sequence, the content of these questionnaires either on a laptop or on a handheld computer. Instructions on the kind of device to be used were provided to data-coders in individual sealed and opaque envelopes. Study conditions were controlled and the data entry process performed in a quiet environment. The authors compared the duration of the data recording process, the number of errors and users' satisfaction with the two devices. The authors divided errors into two separate categories, typing and missing data errors. The original paper-based questionnaire was used as a gold-standard. The overall duration of the recording process was significantly reduced (2.0 versus 3.3 min) when data were recorded on the laptop computer (p < 0.001). Data accuracy also improved. There were 5.8 typing errors per 1,000 entries with the laptop compared to 8.4 per 1,000 with the handheld computer (p < 0.001). The difference was even more important for missing data which decreased from 22.8 to 2.9 per 1,000 entries when a laptop was used (p < 0.001). Users found the laptop easier, faster and more satisfying to use than the handheld computer. Despite the increasing use of handheld computers for electronic data collection in clinical research, these devices should be used with caution. They double the duration of the data entry process and significantly increase the risk of typing errors and missing data. This may become a particularly crucial issue in studies where these devices are provided to patients or healthcare workers, unfamiliar with computer technologies, for self

Handheld vs. Laptop Computers for Electronic Data Collection in Clinical Research: A Crossover Randomized Trial

PubMed Central

Haller, Guy; Haller, Dagmar M.; Courvoisier, Delphine S.; Lovis, Christian

2009-01-01

Objective To compare users' speed, number of entry errors and satisfaction in using two current devices for electronic data collection in clinical research: handheld and laptop computers. Design The authors performed a randomized cross-over trial using 160 different paper-based questionnaires and representing altogether 45,440 variables. Four data coders were instructed to record, according to a random predefined and equally balanced sequence, the content of these questionnaires either on a laptop or on a handheld computer. Instructions on the kind of device to be used were provided to data-coders in individual sealed and opaque envelopes. Study conditions were controlled and the data entry process performed in a quiet environment. Measurements The authors compared the duration of the data recording process, the number of errors and users' satisfaction with the two devices. The authors divided errors into two separate categories, typing and missing data errors. The original paper-based questionnaire was used as a gold-standard. Results The overall duration of the recording process was significantly reduced (2.0 versus 3.3 min) when data were recorded on the laptop computer (p < 0.001). Data accuracy also improved. There were 5.8 typing errors per 1,000 entries with the laptop compared to 8.4 per 1,000 with the handheld computer (p < 0.001). The difference was even more important for missing data which decreased from 22.8 to 2.9 per 1,000 entries when a laptop was used (p < 0.001). Users found the laptop easier, faster and more satisfying to use than the handheld computer. Conclusions Despite the increasing use of handheld computers for electronic data collection in clinical research, these devices should be used with caution. They double the duration of the data entry process and significantly increase the risk of typing errors and missing data. This may become a particularly crucial issue in studies where these devices are provided to patients or healthcare

Design issues for semi-passive optical communication devices

NASA Astrophysics Data System (ADS)

Glaser, I.

2007-09-01

Optical smart cards are devices containing a retro-reflector, light modulator, and some computing and data storage capabilities to affect semi-passive communication. They do not produce light; instead they modulate and send back light received from a stationary unit. These devices can replace contact-based smart cards as well as RF based ones for applications ranging from identification to transmitting and validating data. Since their transmission is essentially focused on the receiving unit, they are harder to eavesdrop than RF devices, yet need no physical contact or alignment. In this paper we explore optical design issues of these devices and estimate their optical behavior. Specifically, we analyze how these compact devices can be optimized for selected application profiles. Some of the key parameters addressed are effective light efficiency (how much modulated signal can be received by the stationary unit given the amount of light it transmits), range of tilt angles (angle between device surface normal to the line connecting the optical smart card with the stationary unit) through which the device would be effective, and power requirements of the semi-passive unit. In addition, issues concerning compact packaging of this device are discussed. Finally, results of the analysis are employed to produce a comparison of achievable capabilities of these optical smart cards, as opposed to alternative devices, and discuss potential applications were they can be best utilized.

Handheld optical coherence tomography-reflectance confocal microscopy probe for detection of basal cell carcinoma and delineation of margins

NASA Astrophysics Data System (ADS)

Iftimia, Nicusor; Yélamos, Oriol; Chen, Chih-Shan J.; Maguluri, Gopi; Cordova, Miguel A.; Sahu, Aditi; Park, Jesung; Fox, William; Alessi-Fox, Christi; Rajadhyaksha, Milind

2017-07-01

We present a hand-held implementation and preliminary evaluation of a combined optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) probe for detecting and delineating the margins of basal cell carcinomas (BCCs) in human skin in vivo. A standard OCT approach (spectrometer-based) with a central wavelength of 1310 nm and 0.11 numerical aperture (NA) was combined with a standard RCM approach (830-nm wavelength and 0.9 NA) into a common path hand-held probe. Cross-sectional OCT images and enface RCM images are simultaneously displayed, allowing for three-dimensional microscopic assessment of tumor morphology in real time. Depending on the subtype and depth of the BCC tumor and surrounding skin conditions, OCT and RCM imaging are able to complement each other, the strengths of each helping overcome the limitations of the other. Four representative cases are summarized, out of the 15 investigated in a preliminary pilot study, demonstrating how OCT and RCM imaging may be synergistically combined to more accurately detect BCCs and more completely delineate margins. Our preliminary results highlight the potential benefits of combining the two technologies within a single probe to potentially guide diagnosis as well as treatment of BCCs.

Optical limiting device and method of preparation thereof

DOEpatents

Wang, Hsing-Lin; Xu, Su; McBranch, Duncan W.

2003-01-01

Optical limiting device and method of preparation thereof. The optical limiting device includes a transparent substrate and at least one homogeneous layer of an RSA material in polyvinylbutyral attached to the substrate. The device may be produced by preparing a solution of an RSA material, preferably a metallophthalocyanine complex, and a solution of polyvinylbutyral, and then mixing the two solutions together to remove air bubbles. The resulting solution is layered onto the substrate and the solvent is evaporated. The method can be used to produce a dual tandem optical limiting device.

Magneto-optical non-reciprocal devices in silicon photonics

PubMed Central

Shoji, Yuya; Mizumoto, Tetsuya

2014-01-01

Silicon waveguide optical non-reciprocal devices based on the magneto-optical effect are reviewed. The non-reciprocal phase shift caused by the first-order magneto-optical effect is effective in realizing optical non-reciprocal devices in silicon waveguide platforms. In a silicon-on-insulator waveguide, the low refractive index of the buried oxide layer enhances the magneto-optical phase shift, which reduces the device footprints. A surface activated direct bonding technique was developed to integrate a magneto-optical garnet crystal on the silicon waveguides. A silicon waveguide optical isolator based on the magneto-optical phase shift was demonstrated with an optical isolation of 30 dB and insertion loss of 13 dB at a wavelength of 1548 nm. Furthermore, a four port optical circulator was demonstrated with maximum isolations of 15.3 and 9.3 dB in cross and bar ports, respectively, at a wavelength of 1531 nm. PMID:27877640

Handheld four-wavelength retinal vessel oximeter

NASA Astrophysics Data System (ADS)

Heaton, Larry C.; Smith, Matthew H.; Denninghoff, Kurt R.; Hillman, Lloyd W.

2000-06-01

Several techniques for measuring the oxygen saturation of blood in retinal vessels have been reported. One interesting application of retinal vessel oximetry is the identification of occult blood loss in trauma victims. However, all the devices described to date are too bulky and cumbersome to be used in a trauma bay or in the field. We present a design for a handheld instrument that performs four-wavelength retinal vessel oximetry. This device is comparable in size and weight to a commercially available camcorder, and is suitable for use in the trauma bay. The compact size of this device could also extend its applications beyond traditional clinical settings, as it could be used by primary care physicians and home health care workers for the screening and monitoring of ophthalmic diseases. Principles of operation and preliminary data from the device will be described.

The use of a handheld Raman system for virus detection

NASA Astrophysics Data System (ADS)

Song, Chunyuan; Driskell, Jeremy D.; Tripp, Ralph A.; Cui, Yiping; Zhao, Yiping

2012-06-01

The combination of surface enhanced Raman spectroscopy (SERS) with a handheld Raman system would lead to a powerful portable device for defense and security applications. The Thermo Scientific FirstDefender RM instrument is a 785-nm handheld Raman spectrometer intended for rapid field identification of unknown solid and liquid samples. Its sensitivity and effectiveness for SERS-based detection was initially confirmed by evaluating detection of 1,2-di(4- pyridyl)ethylene as a reporter molecule on a silver nanorod (AgNR) substrate, and the results are comparable to those from a confocal Bruker Raman system. As avian influenza A viruses (AIV) are recognized as an important emerging threat to public health, this portable handheld Raman spectrometer is used, for the first time, to detect and identify avian influenza A viruses using a multi-well AgNR SERS chip. The SERS spectra obtained had rich peaks which demonstrated that the instrument can be effectively used for SERS-based influenza virus detection. According to the SERS spectra, these different influenza viruses were distinguished from the negative control via the principal component analysis and by partial least squares-discriminate analysis. Together, these results show that the combination effective SERS substrates when combined with a portable Raman spectrometer provides a powerful field device for chemical and biological sensing.

Photonic variable delay devices based on optical birefringence

NASA Technical Reports Server (NTRS)

Yao, X. Steve (Inventor)

2005-01-01

Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the ladder experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, an index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines/cm2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

A Foothold for Handhelds.

ERIC Educational Resources Information Center

Joyner, Amy

2003-01-01

Handheld computers provide students tremendous computing and learning power at about a 10th the cost of a regular computer. Describes the evolution of handhelds; provides some examples of their uses; and cites research indicating they are effective classroom tools that can improve efficiency and instruction. A sidebar lists handheld resources.…

A new miniature hand-held solar-blind reagentless standoff chemical, biological, and explosives (CBE) sensor

NASA Astrophysics Data System (ADS)

Hug, W. F.; Reid, R. D.; Bhartia, R.; Lane, A. L.

2008-04-01

Improvised explosive devices (IEDs), vehicle-borne improvised explosive devices (VBIEDs), and suicide bombers are a major threat to many countries and their citizenry. The ability to detect trace levels of these threats with a miniature, hand-held, reagentless, standoff sensor represents a major improvement in the state of the art of CBE surface sensors. Photon Systems, Inc., in collaboration with Jet Propulsion Laboratory, recently demonstrated a new technology hand-held sensor for reagentless, close-range, standoff detection and identification of trace levels CBE materials on surfaces. This targeted ultraviolet CBE (TUCBE) sensor is the result of an Army Phase I STTR program. The resulting 5lb, 5W, flashlight-sized sensor can discriminate CBE from background materials using a combination of deep UV excited resonance Raman (RR) and laser induced native fluorescence (LINF) emissions resulting from excitation by a new technology deep UV laser. Detection and identification is accomplished in less than 1ms. Standoff excitation of suspicious packages, vehicles, persons, and other objects that may contain hazardous materials is accomplished using wavelengths below 250nm where Raman and native fluorescence emissions occupy distinctly different wavelength regions. This enables simultaneous detection of RR and LINF emissions with no interferences. The sensor employs fused RR/LINF chemometric methods to extract the identity of targeted materials from background clutter. Photon Systems has demonstrated detection and identification of 100ng/cm2 of explosives materials at a distance of 1 meter using a sensor with 3.8 cm optical aperture. Expansion of the optical aperture to 38 cm in a lantern-sized sensor will enable similar detection and identification of CBE materials at standoff distances of 10 meters. As a result of excitation and detection in the deep UV and the use of a gated detection system, the sensor is solar blind and can operate in full daylight conditions.

Quasi-Phasematched Nonlinear Optics: Materials and Devices

DTIC Science & Technology

2007-04-16

the soliton energy in pump, signal and idler waves as a function of the final wave- vector mismatch in the chirped QPM gratings. We see good agreement...devices including OP-GaAs devices for broadband optical parametric generation (OPG) at mid-infrared wavelengths, bulk PPLN devices for soliton ...Carrasco, and L. Torner,"Engineering of multi-color spatial solitons with chirped-period quasi-phase-matching gratings in optical parametric amplification

Optical fiber end-facet polymer suspended-mirror devices

NASA Astrophysics Data System (ADS)

Yao, Mian; Wu, Jushuai; Zhang, A. Ping; Tam, Hwa-Yaw; Wai, P. K. A.

2017-04-01

This paper presents a novel optical fiber device based on a polymer suspended mirror on the end facet of an optical fiber. With an own-developed optical 3D micro-printing technology, SU-8 suspended-mirror devices (SMDs) were successfully fabricated on the top of a standard single-mode optical fiber. Optical reflection spectra of the fabricated SU- 8 SMDs were measured and compared with theoretical analysis. The proposed technology paves a way towards 3D microengineering of the small end-facet of optical fibers to develop novel fiber-optic sensors.

Optical waveguide device with an adiabatically-varying width

DOEpatents

Watts,; Michael R. , Nielson; Gregory, N [Albuquerque, NM

2011-05-10

Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

Interferometric ring lasers and optical devices

DOEpatents

Hohimer, John P.; Craft, David C.

1995-01-01

Two ring diode lasers are optically coupled together to produce tunable, stable output through a Y-junction output coupler which may also be a laser diode or can be an active waveguide. These devices demonstrate a sharp peak in light output with an excellent side-mode-rejection ratio. The rings can also be made of passive or active waveguide material. With additional rings the device is a tunable optical multiplexer/demultiplexer.

Technical and operational users' opinions of a handheld device to detect directed energy.

PubMed

Boyd, Andrew D; Naiman, Melissa; Stevenson, Greer W; Preston, Richard; Valenta, Annette L

2013-05-01

Lasers, a form of directed energy (DE), are a threat to pilots and Air Force personnel. In light of this threat, a handheld medical device called the "Tricorder" is under development to improve situational awareness of DE. Current operational procedures do not include methods for recording or handling new information regarding DE. The purpose of this study was to understand Air Force personnel opinions and beliefs about desired features and operational use to enhance user acceptance of the Tricorder. Q-methodology was implemented to study opinions and beliefs related to DE. Two groups were approached, medical personnel in the Illinois Air National Guard and four active duty members of an Air Force Rescue Squadron. Both groups completed the same Q-sort of both operational and equipment concerns. Six opinion sets regarding operational concerns described 61% of the total variation in perceptions among participants. The factors were: concern over health effects, implications to individuals, combat/tactical concerns, force health protection, and theater/tactical concerns. Five opinion sets described 68% of the variation in the equipment functions perceived as most important. The participants indicated that ideally the device should measure exposure, enhance laser detection/response, support night vision and ease of use, detect threats, and enhance combat medicine. This survey revealed the complexity of equipment and the operational implications of detecting DE. Q-methodology is a unique strategy to both evaluate technology and explore users' concerns.

Poling of Microwave Electro-Optic Devices

NASA Technical Reports Server (NTRS)

Singer, Kenneth D.

1997-01-01

The desire to transmit high frequency, microwave RF signals over fiber optic cables has necessitated the need for electro-optic modulation devices. However, in order to reap these potential benefits, it is necessary to develop the devices and their associated fabrication processes, particularly those processes associated with the poling of the devices. To this end, we entered into a cooperative research agreement with Richard Kunath of NASA LeRC. A graduate student in my group, Tony Kowalczyk, worked closely with the group at NASA to develop processes for construction of a microwave frequency electro-optic modulator. Materials were commercially obtained from Amoco Chemical and in collaboration with Lockheed-Martin. The photolithography processes were developed at NASA LeRC and the electric-field poling process was carried out in our laboratory at CWRU. During the grant period, the poling process conditions were investigated for these multilayer devices. Samples were poled and the resulting nonlinear optical properties were evaluated in our laboratory. Following the grant period, Kowalczyk went to NASA under a NRC fellowship, and I continued to collaborate as a consultant. Publications listed at the end of this report came out of this work. Another manuscript is in preparation and will be submitted shortly.

Handheld, rapidly switchable, anterior/posterior segment swept source optical coherence tomography probe

PubMed Central

Nankivil, Derek; Waterman, Gar; LaRocca, Francesco; Keller, Brenton; Kuo, Anthony N.; Izatt, Joseph A.

2015-01-01

We describe the first handheld, swept source optical coherence tomography (SSOCT) system capable of imaging both the anterior and posterior segments of the eye in rapid succession. A single 2D microelectromechanical systems (MEMS) scanner was utilized for both imaging modes, and the optical paths for each imaging mode were optimized for their respective application using a combination of commercial and custom optics. The system has a working distance of 26.1 mm and a measured axial resolution of 8 μm (in air). In posterior segment mode, the design has a lateral resolution of 9 μm, 7.4 mm imaging depth range (in air), 4.9 mm 6dB fall-off range (in air), and peak sensitivity of 103 dB over a 22° field of view (FOV). In anterior segment mode, the design has a lateral resolution of 24 μm, imaging depth range of 7.4 mm (in air), 6dB fall-off range of 4.5 mm (in air), depth-of-focus of 3.6 mm, and a peak sensitivity of 99 dB over a 17.5 mm FOV. In addition, the probe includes a wide-field iris imaging system to simplify alignment. A fold mirror assembly actuated by a bi-stable rotary solenoid was used to switch between anterior and posterior segment imaging modes, and a miniature motorized translation stage was used to adjust the objective lens position to correct for patient refraction between −12.6 and + 9.9 D. The entire probe weighs less than 630 g with a form factor of 20.3 x 9.5 x 8.8 cm. Healthy volunteers were imaged to illustrate imaging performance. PMID:26601014

Optical-microwave interactions in semiconductor devices

NASA Astrophysics Data System (ADS)

Figueroa, L.; Slayman, C. W.; Yen, H. W.

1981-03-01

The results of an extensive characterization of microwave-optical devices is presented. The study has concentrated in the optical injection locking of IMPATT oscillators, high-speed analog modulation of (GaAl)As injection laser, mode-locking of (GaAl)As injection laser, and high-speed optical detectors.

Single-pipetting microfluidic assay device for rapid detection of Salmonella from poultry package.

PubMed

Fronczek, Christopher F; You, David J; Yoon, Jeong-Yeol

2013-02-15

A direct, sensitive, near-real-time, handheld optical immunoassay device was developed to detect Salmonella typhimurium in the naturally occurring liquid from fresh poultry packages (hereafter "chicken matrix"), with just single pipetting of sample (i.e., no filtration, culturing and/or isolation, thus reducing the assay time and the error associated with them). Carboxylated, polystyrene microparticles were covalently conjugated with anti-Salmonella, and the immunoagglutination due to the presence of Salmonella was detected by reading the Mie scatter signals from the microfluidic channels using a handheld device. The presence of chicken matrix did not affect the light scatter signal, since the optical parameters (particle size d, wavelength of incident light λ and scatter angle θ) were optimized to minimize the effect of sample matrix (animal tissues and blood proteins, etc.). The sample was loaded into a microfluidic chip that was split into two channels, one pre-loaded with vacuum-dried, antibody-conjugated particles and the other with vacuum-dried, bovine serum albumin-conjugated particles. This eliminated the need for a separate negative control, effectively minimizing chip-to-chip and sample-to-sample variations. Particles and the sample were diffused in-channel through chemical agitation by Tween 80, also vacuum-dried within the microchannels. Sequential mixing of the sample to the reagents under a strict laminar flow condition synergistically improved the reproducibility and linearity of the assay. In addition, dried particles were shown to successfully detect lower Salmonella concentrations for up to 8 weeks. The handheld device contains simplified circuitry eliminating unnecessary adjustment stages, providing a stable signal, thus maximizing sensitivity. Total assay time was 10 min, and the detection limit 10 CFU mL(-1) was observed in all matrices, demonstrating the suitability of this device for field assays. Copyright © 2012 Elsevier B.V. All rights

Interferometric ring lasers and optical devices

DOEpatents

Hohimer, J.P.; Craft, D.C.

1995-03-14

Two ring diode lasers are optically coupled together to produce tunable, stable output through a Y-junction output coupler which may also be a laser diode or can be an active waveguide. These devices demonstrate a sharp peak in light output with an excellent side-mode-rejection ratio. The rings can also be made of passive or active waveguide material. With additional rings the device is a tunable optical multiplexer/demultiplexer. 11 figs.

Immersive Input Display Device (I2D2) for tactical information viewing

NASA Astrophysics Data System (ADS)

Tremper, David E.; Burnett, Kevin P.; Malloy, Andrew R.; Wert, Robert

2006-05-01

Daylight readability of hand-held displays has been an ongoing issue for both commercial and military applications. In an effort to reduce the effects of ambient light on the readability of military displays, the Naval Research Laboratory (NRL) began investigating and developing advanced hand-held displays. Analysis and research of display technologies with consideration for vulnerability to environmental conditions resulted in the complete design and fabrication of the hand-held Immersive Input Display Device (I2D2) monocular. The I2D2 combines an Organic Light Emitting Diode (OLED) SVGA+ micro-display developed by eMagin Corporation with an optics configuration inside a cylindrical housing. A rubber pressure-eyecup allows view ability only when the eyecup is depressed, eliminating light from both entering and leaving the device. This feature allows the I2D2 to be used during the day, while not allowing ambient light to affect the readability. It simultaneously controls light leakage, effectively eliminating the illumination, and thus preserving the tactical position, of the user in the dark. This paper will examine the characteristics and introduce the design of the I2D2.

Suitability of capillary blood obtained by a minimally invasive lancet technique to detect subclinical ketosis in dairy cows by using 3 different electronic hand-held devices.

PubMed

Kanz, P; Drillich, M; Klein-Jöbstl, D; Mair, B; Borchardt, S; Meyer, L; Schwendenwein, I; Iwersen, M

2015-09-01

The objective of this study was to evaluate the suitability of capillary blood obtained by a minimally invasive lancet technique to detect subclinical ketosis in 49 prepartum and 191 postpartum Holstein-Friesian cows using 3 different electronic hand-held devices [FreeStyle Precision (FSP, Abbott), GlucoMen LX Plus (GLX, A. Menarini), NovaVet (NOV, Nova Biomedical)]. The β-hydroxybutyrate (BHBA) concentration in serum harvested from coccygeal blood samples was analyzed in a laboratory and used as a reference value. Capillary samples were obtained from the skin of the exterior vulva by using 1 of 3 different lancets. In all samples, the concentration of BHBA was immediately analyzed with all 3 hand-held devices used in random order. All lancets used in the study were eligible for capillary blood collection but differed in the total number of incisions needed. Spearman correlation coefficients between the BHBA concentrations in capillary blood and the reference test were highly significant with 83% for the FSP, 73% for the NOV, and 63% for the GLX. Using capillary blood, the FSP overestimated the mean BHBA concentration compared with the reference test (+0.08 mmol/L), whereas the GLX and NOV underestimated the mean concentration (-0.07 and -0.01 mmol/L). When a BHBA concentration of 1.2 mmol/L in serum was used to define subclinical ketosis, the corresponding analyses of receiver operating characteristics resulted in optimized thresholds for capillary blood of 1.1 mmol/L for the NOV and GLX devices, and of 1.0 mmol/L for the FSP. Based on these thresholds, sensitivities (Se) and specificities (Sp) were 89 and 84% for the NOV, 80 and 89% for the GLX, and 100 and 76% for the FSP. Based on a serum BHBA concentration of 1.4 mmol/L, analyses of receiver operating characteristics resulted in optimized cut-offs of 1.4 mmol/L for the FSP (Se 100%, Sp 92%), 1.3 mmol/L for the NOV (Se 80%, Sp 95%), and 1.1 mmol/L (Se 90%, Sp 85%) for the GLX. Using these optimized thresholds

Superlattice optical device

DOEpatents

Biefeld, R.M.; Fritz, I.J.; Gourley, P.L.; Osbourn, G.C.

A semiconductor optical device which includes a superlattice having direct transitions between conduction band and valence band states with the same wave vector, the superlattice being formed from a plurality of alternating layers of two or more different materials, at least the material with the smallest bandgap being an indirect bandgap material.

Using medical knowledge sources on handheld computers--a qualitative study among junior doctors.

PubMed

Axelson, Christian; Wårdh, Inger; Strender, Lars-Erik; Nilsson, Gunnar

2007-09-01

The emergence of mobile computing could have an impact on how junior doctors learn. To exploit this opportunity it is essential to understand their information seeking process. To explore junior doctors' experiences of using medical knowledge sources on handheld computers. Interviews with five Swedish junior doctors. A qualitative manifest content analysis of a focus group interview followed by a qualitative latent content analysis of two individual interviews. A focus group interview showed that users were satisfied with access to handheld medical knowledge sources, but there was concern about contents, reliability and device dependency. Four categories emerged from individual interviews: (1) A feeling of uncertainty about using handheld technology in medical care; (2) A sense of security that handhelds can provide; (3) A need for contents to be personalized; (4) A degree of adaptability to make the handheld a versatile information tool. A theme was established to link the four categories together, as expressed in the Conclusion section. Junior doctors' experiences of using medical knowledge sources on handheld computers shed light on the need to decrease uncertainty about clinical decisions during medical internship, and to find ways to influence the level of self-confidence in the junior doctor's process of decision-making.

Initial experience with a handheld device digital imaging and communications in medicine viewer: OsiriX mobile on the iPhone.

PubMed

Choudhri, Asim F; Radvany, Martin G

2011-04-01

Medical imaging is commonly used to diagnose many emergent conditions, as well as plan treatment. Digital images can be reviewed on almost any computing platform. Modern mobile phones and handheld devices are portable computing platforms with robust software programming interfaces, powerful processors, and high-resolution displays. OsiriX mobile, a new Digital Imaging and Communications in Medicine viewing program, is available for the iPhone/iPod touch platform. This raises the possibility of mobile review of diagnostic medical images to expedite diagnosis and treatment planning using a commercial off the shelf solution, facilitating communication among radiologists and referring clinicians.

MS Mastracchio uses the hand-held laser rangefinder during STS-106

NASA Image and Video Library

2000-09-18

STS106-320-014 (10 September 2000) --- Astronaut Richard A. Mastracchio, mission specialist, uses a handheld laser device on the aft flight deck of the Space Shuttle Atlantis to track the range of the International Space Station during rendezvous operations.

The New Pretender: A Large UK Case Series of Retinal Injuries in Children Secondary to Handheld Lasers.

PubMed

Raoof, Naz; Bradley, Patrick; Theodorou, Maria; Moore, Anthony T; Michaelides, Michel

2016-11-01

To characterize a large single-center series of retinal injuries in children secondary to handheld laser devices, with emphasis on potential prognostic factors. Retrospective case series. Sixteen children (24 eyes) with retinal injuries secondary to handheld lasers were identified from our electronic patient record system. Case notes, digital fundus photography, and spectral-domain optical coherence tomography images were reviewed. The mean age of affected children was 12.7 years (range 9-16 years), with 12 male and 4 female subjects. Mean follow up was 5.4 months (range 1-23 months). Five children (31%) were referred as suspected retinal dystrophies. The mean logMAR visual acuity at presentation was 0.30 (20/40) (range -0.20 [20/12.5] to 1.6 [20/800]). Eleven children (69%; 15 eyes) had "mild" injuries with focal retinal disruption confined to the photoreceptor and ellipsoid layers; such injuries were associated with a better prognosis, the mean visual acuity at presentation being 0.10 (20/25). "Moderate" injuries were seen in 3 eyes of 2 children, with retinal disruption confined to the outer retinal layer but diffuse rather than focal in nature. Three patients (4 eyes) had "severe" injuries, with subfoveal outer retinal architecture loss and overlying hyperreflective material in inner retinal layers. Retinal injuries secondary to handheld laser devices may be difficult to diagnose and are likely underreported. It is important that such data are in the public domain, so regulatory authorities recognize the importance of laser retinopathy as an avoidable cause of childhood visual impairment and take steps to minimize the incidence and impact of laser injuries. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

NITINOL Interconnect Device for Optical Fiber Waveguides

DTIC Science & Technology

1981-07-01

LE EL,~NAVSEA REPORT NO. S27L~kV-NL 4P fNSWNC TR 81-129 1 JULY 1981 0 NITINOL INTERC&INECT DEVICE FOR OPTICAL FIBER WAVEGUIDES FINAL REPORT A...ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER NSWC TR 81-129I 1-19 -A )ci , ’ 4 TI TL E (and Sbtitle) S. TYPE OF REPORT & PERIOD COVERED NITINOL ... NITINOL Optical Fibers 20. ABSTRACT (Continue on reverse side if neceeewy and identify by block number) Two different interconnect devices for optical

Optical biosensors: a revolution towards quantum nanoscale electronics device fabrication.

PubMed

Dey, D; Goswami, T

2011-01-01

The dimension of biomolecules is of few nanometers, so the biomolecular devices ought to be of that range so a better understanding about the performance of the electronic biomolecular devices can be obtained at nanoscale. Development of optical biomolecular device is a new move towards revolution of nano-bioelectronics. Optical biosensor is one of such nano-biomolecular devices that has a potential to pave a new dimension of research and device fabrication in the field of optical and biomedical fields. This paper is a very small report about optical biosensor and its development and importance in various fields.

Multichannel optical sensing device

DOEpatents

Selkowitz, S.E.

1985-08-16

A multichannel optical sensing device is disclosed, for measuring the outdoor sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optical elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

Multichannel optical sensing device

DOEpatents

Selkowitz, Stephen E.

1990-01-01

A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

Handheld single photon emission computed tomography (handheld SPECT) navigated video-assisted thoracoscopic surgery of computer tomography-guided radioactively marked pulmonary lesions.

PubMed

Müller, Joachim; Putora, Paul Martin; Schneider, Tino; Zeisel, Christoph; Brutsche, Martin; Baty, Florent; Markus, Alexander; Kick, Jochen

2016-09-01

Radioactive marking can be a valuable extension to minimally invasive surgery. The technique has been clinically applied in procedures involving sentinel lymph nodes, parathyroidectomy as well as interventions in thoracic surgery. Improvements in equipment and techniques allow one to improve the limits. Pulmonary nodules are frequently surgically removed for diagnostic or therapeutic reasons; here video-assisted thoracoscopic surgery (VATS) is the preferred technique. VATS might be impossible with nodules that are small or located deep in the lung. In this study, we examined the clinical application and safety of employing the newly developed handheld single photon emission tomography (handheld SPECT) device in combination with CT-guided radioactive marking of pulmonary nodules. In this pilot study, 10 subjects requiring surgical resection of a pulmonary nodule were included. The technique involved CT-guided marking of the target nodule with a 20-G needle, with subsequent injection of 25-30 MBq (effective: 7-14 MBq) Tc-99m MAA (Macro Albumin Aggregate). Quality control was made with conventional SPECT-CT to confirm the correct localization and exclude possible complications related to the puncture procedure. VATS was subsequently carried out using the handheld SPECT to localize the radioactivity intraoperatively and therefore the target nodule. A 3D virtual image was superimposed on the intraoperative visual image for surgical guidance. In 9 of the 10 subjects, the radioactive application was successfully placed directly in or in the immediate vicinity of the target nodule. The average size of the involved nodules was 9 mm (range 4-15). All successfully marked nodules were subsequently completely excised (R0) using VATS. The procedure was well tolerated. An asymptomatic clinically insignificant pneumothorax occurred in 5 subjects. Two subjects were found to have non-significant discrete haemorrhage in the infiltration canal of the needle. In a single subject, the

Analysis of Polarizing Optical Systems for Digital Optical Computing with Symmetric Self Electrooptic Devices

DTIC Science & Technology

1991-03-31

I AD-A232 768 I Annual Report Analysis of Polarizing Optical Systems for Digital Optical Computing with I ’ Symmetric Self Electrooptic Devices I To...TTU AND SuSiIU S. PUNDIN mUMBERS Polarizing Optical Systems for Digital Optical Computing with Symmetric Self Electrooptic Devices AFOSR-89-0542 C...UTION COO$ UNLIMITED 13. ABSTRACT (MAxnum00woUw Two architectural approaches have dominated the field of optical computing . The first appAch uses

Monitoring of WEEE plastics in regards to brominated flame retardants using handheld XRF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aldrian, Alexia, E-mail: alexia.aldrian@unileoben.ac.at; Ledersteger, Alfred, E-mail: a.ledersteger@saubermacher.at; Pomberger, Roland, E-mail: roland.pomberger@unileoben.ac.at

Highlights: • Specification of an empirical factor for conversion from bromine to PBB and PBDE. • The handheld XRF device was validated for this particular application. • A very large number of over 4600 pieces of monitor housings was analysed. • The recyclable fraction mounts up to 85% for TV but only 53% of PC waste plastics. • A high percentage of pieces with bromine contents of over 50,000 ppm was obtained. - Abstract: This contribution is focused on the on-site determination of the bromine content in waste electrical and electronic equipment (WEEE), in particular waste plastics from television setsmore » (TV) and personal computer monitors (PC) using a handheld X-ray fluorescence (XRF) device. The described approach allows the examination of samples in regards to the compliance with legal specifications for polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) directly after disassembling and facilitates the sorting out of plastics with high contents of brominated flame retardants (BFRs). In all, over 3000 pieces of black (TV) and 1600 pieces of grey (PC) plastic waste were analysed with handheld XRF technique for this study. Especially noticeable was the high percentage of pieces with a bromine content of over 50,000 ppm for TV (7%) and PC (39%) waste plastics. The applied method was validated by comparing the data of handheld XRF with results obtained by GC–MS. The results showed the expected and sufficiently accurate correlation between these two methods. It is shown that handheld XRF technique is an effective tool for fast monitoring of large volumes of WEEE plastics in regards to BFRs for on-site measurements.« less

Guided-Wave TeO2 Acousto-Optic Devices

DTIC Science & Technology

1991-01-12

In this research program, Guided-wave TeO2 Acousto - Optic Devices, the properties of surface acoustic waves on tellurium dioxide single crystal...surfaces has been studied for its potential applications as acousto - optic signal processing devices. Personal computer based numerical method has been...interaction with laser beams. Use of the acousto - optic probe, the surface acoustic wave velocity and field distribution have been obtained and compared

Texting while driving: is speech-based text entry less risky than handheld text entry?

PubMed

He, J; Chaparro, A; Nguyen, B; Burge, R J; Crandall, J; Chaparro, B; Ni, R; Cao, S

2014-11-01

Research indicates that using a cell phone to talk or text while maneuvering a vehicle impairs driving performance. However, few published studies directly compare the distracting effects of texting using a hands-free (i.e., speech-based interface) versus handheld cell phone, which is an important issue for legislation, automotive interface design and driving safety training. This study compared the effect of speech-based versus handheld text entries on simulated driving performance by asking participants to perform a car following task while controlling the duration of a secondary text-entry task. Results showed that both speech-based and handheld text entries impaired driving performance relative to the drive-only condition by causing more variation in speed and lane position. Handheld text entry also increased the brake response time and increased variation in headway distance. Text entry using a speech-based cell phone was less detrimental to driving performance than handheld text entry. Nevertheless, the speech-based text entry task still significantly impaired driving compared to the drive-only condition. These results suggest that speech-based text entry disrupts driving, but reduces the level of performance interference compared to text entry with a handheld device. In addition, the difference in the distraction effect caused by speech-based and handheld text entry is not simply due to the difference in task duration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of a digital and an optical analogue hand-held refractometer for the measurement of canine urine specific gravity.

PubMed

Paris, J K; Bennett, A D; Dodkin, S J; Gunn-Moore, D A

2012-05-05

Urine specific gravity (USG) is used clinically as a measure of urine concentration, and is routinely assessed by refractometry. A comparison between optical analogue and digital refractometers for evaluation of canine urine has not been reported. The aim of this study was to compare a digital and an optical analogue hand-held refractometer for the measurement of canine USG, and to assess correlation with urine osmolality. Prospective study. Free-catch urine samples were collected from 285 hospitalised adult dogs, and paired USG readings were obtained with a digital and an optical analogue refractometer. In 50 dogs, urine osmolality was also measured using a freezing point depression osmometer. There was a small but statistically significant difference between the two refractometers (P<0.001), with the optical analogue refractometer reading higher than the digital refractometer (mean difference 0.0006, sd 0.0012). Paired refractometer measurements varied by <0.002 in 91.5 per cent of cases. The optical analogue and digital refractometer readings showed excellent correlation with osmolality (r=0.980 and r=0.977, respectively, P<0.001 in both cases). Despite statistical significance, the difference between the two refractometers is unlikely to be clinically significant. Both instruments provide an accurate assessment of USG in dogs.

Novel hand-held device for exhaled nitric oxide-analysis in research and clinical applications.

PubMed

Hemmingsson, Tryggve; Linnarsson, Dag; Gambert, Rudolf

2004-12-01

Changes in expired nitric oxide (NO) occur in airway inflammation and have proved to be important in the monitoring of inflammatory disease processes such as asthma. We set out to develop a novel hand-held NO-analyzer with a performance comparable to the present more costly and complex chemiluminescence instruments. The new device is based on a specially designed electrochemical sensor, where we have developed a novel sampling and analysis technology, compensating for the relatively slow response properties of the electrochemical sensor technique. A Lowest Detection Limit in NO-analysis from reference gas tests of less than 3 ppb and a response time of 15 seconds together with an average precision in human breath measurements of 1.4 ppb were obtained. We also show an agreement with the existing 'gold standard' FENO measurement technique, within 0.5 ppb in a group of 19 subjects together with a high linearity and accuracy compared to reference gases. The new analyzer enables affordable monitoring of inflammatory airway diseases in research and routine clinical practice.

Critical care procedure logging using handheld computers

PubMed Central

Carlos Martinez-Motta, J; Walker, Robin; Stewart, Thomas E; Granton, John; Abrahamson, Simon; Lapinsky, Stephen E

2004-01-01

Introduction We conducted this study to evaluate the feasibility of implementing an internet-linked handheld computer procedure logging system in a critical care training program. Methods Subspecialty trainees in the Interdepartmental Division of Critical Care at the University of Toronto received and were trained in the use of Palm handheld computers loaded with a customized program for logging critical care procedures. The procedures were entered into the handheld device using checkboxes and drop-down lists, and data were uploaded to a central database via the internet. To evaluate the feasibility of this system, we tracked the utilization of this data collection system. Benefits and disadvantages were assessed through surveys. Results All 11 trainees successfully uploaded data to the central database, but only six (55%) continued to upload data on a regular basis. The most common reason cited for not using the system pertained to initial technical problems with data uploading. From 1 July 2002 to 30 June 2003, a total of 914 procedures were logged. Significant variability was noted in the number of procedures logged by individual trainees (range 13–242). The database generated by regular users provided potentially useful information to the training program director regarding the scope and location of procedural training among the different rotations and hospitals. Conclusion A handheld computer procedure logging system can be effectively used in a critical care training program. However, user acceptance was not uniform, and continued training and support are required to increase user acceptance. Such a procedure database may provide valuable information that may be used to optimize trainees' educational experience and to document clinical training experience for licensing and accreditation. PMID:15469577

Handheld fetal Doppler device for assessing heart rate in neonatal resuscitation.

PubMed

Shimabukuro, Rinshu; Takase, Kozo; Ohde, Sachiko; Kusakawa, Isao

2017-10-01

The use of neonatal three-lead electrocardiograms (Neo-ECG) is suggested for the assessment of heart rate (HR) in neonatal resuscitation, but primary childbirth facilities (i.e. maternity clinics or maternity homes) are not sufficiently equipped for this. The aim of this study was to therefore to confirm the potential of a handheld fetal Doppler device (FDD), widely used to assess HR in labor room resuscitation, and to compare its equivalency to Neo-ECG. In low-risk full-term infants, HR was measured five times per minute in minutes 1-5 after delivery using the FDD and Neo-ECG, and their equivalence compared. The equivalence margin was set at a HR difference of <±5 beats/min and <±5%. Moreover, the times at which HR was displayed were measured for both methods. FDD and Neo-ECG HR correlated strongly (r = 0.977) in 155 measurements in 33 cases. The mean HR difference was -0.123 beats/min (95%CI: -0.594 to +0.345), and the logarithmic transformation of the HR ratio was -0.0003 (95%CI: -0.0020 to +0.0015). The mean HR difference and HR ratio were within the equivalence margin. For HR assessment using the FDD, 155 of 165 measurements (93.9%) could be obtained in <10 s. In HR assessment, FDD is a valid substitute for Neo-ECG in primary childbirth facilities that are not sufficiently equipped for Neo-ECG. © 2017 Japan Pediatric Society.

Radiology on handheld devices: image display, manipulation, and PACS integration issues.

PubMed

Raman, Bhargav; Raman, Raghav; Raman, Lalithakala; Beaulieu, Christopher F

2004-01-01

Handheld personal digital assistants (PDAs) have undergone continuous and substantial improvements in hardware and graphics capabilities, making them a compelling platform for novel developments in teleradiology. The latest PDAs have processor speeds of up to 400 MHz and storage capacities of up to 80 Gbytes with memory expansion methods. A Digital Imaging and Communications in Medicine (DICOM)-compliant, vendor-independent handheld image access system was developed in which a PDA server acts as the gateway between a picture archiving and communication system (PACS) and PDAs. The system is compatible with most currently available PDA models. It is capable of both wired and wireless transfer of images and includes custom PDA software and World Wide Web interfaces that implement a variety of basic image manipulation functions. Implementation of this system, which is currently undergoing debugging and beta testing, required optimization of the user interface to efficiently display images on smaller PDA screens. The PDA server manages user work lists and implements compression and security features to accelerate transfer speeds, protect patient information, and regulate access. Although some limitations remain, PDA-based teleradiology has the potential to increase the efficiency of the radiologic work flow, increasing productivity and improving communication with referring physicians and patients. Copyright RSNA, 2004

Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

NASA Astrophysics Data System (ADS)

Fehm, Thomas Felix; Deán-Ben, Xosé Luís; Razansky, Daniel

2014-10-01

Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

Methods of making composite optical devices employing polymer liquid crystal

DOEpatents

Jacobs, S.D.; Marshall, K.L.; Cerqua, K.A.

1991-10-08

Composite optical devices are disclosed using polymer liquid crystal materials both as optical and adhesive elements. The devices are made by assembling a heated polymer liquid crystal compound, while in a low viscosity form between optically transparent substrates. The molecules of the polymer are oriented, while in the liquid crystalline state and while above the glass transition temperature (T[sub g]) of the polymer, to provide the desired optical effects, such as polarization, and selective reflection. The liquid crystal polymer cements the substrates together to form an assembly providing the composite optical device. 7 figures.

Methods of making composite optical devices employing polymer liquid crystal

DOEpatents

Jacobs, Stephen D.; Marshall, Kenneth L.; Cerqua, Kathleen A.

1991-01-01

Composite optical devices using polymer liquid crystal materials both as optical and adhesive elements. The devices are made by assembling a heated polymer liquid crystal compound, while in a low viscosity form between optically transparent substrates. The molecules of the polymer are oriented, while in the liquid crystalline state and while above the glass transition temperature (T.sub.g) of the polymer, to provide the desired optical effects, such as polarization, and selective reflection. The liquid crystal polymer cements the substrates together to form an assembly providing the composite optical device.

Recent Advances in Photonic Devices for Optical Computing and the Role of Nonlinear Optics-Part II

NASA Technical Reports Server (NTRS)

Abdeldayem, Hossin; Frazier, Donald O.; Witherow, William K.; Banks, Curtis E.; Paley, Mark S.

2007-01-01

The twentieth century has been the era of semiconductor materials and electronic technology while this millennium is expected to be the age of photonic materials and all-optical technology. Optical technology has led to countless optical devices that have become indispensable in our daily lives in storage area networks, parallel processing, optical switches, all-optical data networks, holographic storage devices, and biometric devices at airports. This chapters intends to bring some awareness to the state-of-the-art of optical technologies, which have potential for optical computing and demonstrate the role of nonlinear optics in many of these components. Our intent, in this Chapter, is to present an overview of the current status of optical computing, and a brief evaluation of the recent advances and performance of the following key components necessary to build an optical computing system: all-optical logic gates, adders, optical processors, optical storage, holographic storage, optical interconnects, spatial light modulators and optical materials.

All-optical switching of magnetoresistive devices using telecom-band femtosecond laser

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Li; Chen, Jun-Yang; Wang, Jian-Ping, E-mail: jpwang@umn.edu, E-mail: moli@umn.edu

Ultrafast all-optical switching of the magnetization of various magnetic systems is an intriguing phenomenon that can have tremendous impact on information storage and processing. Here, we demonstrate all-optical switching of GdFeCo alloy films using a telecom-band femtosecond fiber laser. We further fabricate Hall cross devices and electrically readout all-optical switching by measuring anomalous Hall voltage changes. The use of a telecom laser and the demonstrated all-optical switching of magnetoresistive devices represent the first step toward integration of opto-magnetic devices with mainstream photonic devices to enable novel optical and spintronic functionalities.

Driver electronic device use in 2013.

DOT National Transportation Integrated Search

2015-04-01

The percentage of drivers text-messaging or visibly manipulating : hand-held devices increased from 1.5 percent in : 2012 to 1.7 percent in 2013; however, this was not a statistically : significant increase. Driver hand-held cell phone : use decrease...

Perform light and optic experiments in Augmented Reality

NASA Astrophysics Data System (ADS)

Wozniak, Peter; Vauderwange, Oliver; Curticapean, Dan; Javahiraly, Nicolas; Israel, Kai

2015-10-01

In many scientific studies lens experiments are part of the curriculum. The conducted experiments are meant to give the students a basic understanding for the laws of optics and its applications. Most of the experiments need special hardware like e.g. an optical bench, light sources, apertures and different lens types. Therefore it is not possible for the students to conduct any of the experiments outside of the university's laboratory. Simple optical software simulators enabling the students to virtually perform lens experiments already exist, but are mostly desktop or web browser based. Augmented Reality (AR) is a special case of mediated and mixed reality concepts, where computers are used to add, subtract or modify one's perception of reality. As a result of the success and widespread availability of handheld mobile devices, like e.g. tablet computers and smartphones, mobile augmented reality applications are easy to use. Augmented reality can be easily used to visualize a simulated optical bench. The students can interactively modify properties like e.g. lens type, lens curvature, lens diameter, lens refractive index and the positions of the instruments in space. Light rays can be visualized and promote an additional understanding of the laws of optics. An AR application like this is ideally suited to prepare the actual laboratory sessions and/or recap the teaching content. The authors will present their experience with handheld augmented reality applications and their possibilities for light and optic experiments without the needs for specialized optical hardware.

Mobile device-based optical instruments for agriculture

NASA Astrophysics Data System (ADS)

Sumriddetchkajorn, Sarun

2013-05-01

Realizing that a current smart-mobile device such as a cell phone and a tablet can be considered as a pocket-size computer embedded with a built-in digital camera, this paper reviews and demonstrates on how a mobile device can be specifically functioned as a portable optical instrument for agricultural applications. The paper highlights several mobile device-based optical instruments designed for searching small pests, measuring illumination level, analyzing spectrum of light, identifying nitrogen status in the rice field, estimating chlorine in water, and determining ripeness level of the fruit. They are suitable for individual use as well as for small and medium enterprises.

Plasma channel optical pumping device and method

DOEpatents

Judd, O.P.

1983-06-28

A device and method are disclosed for optically pumping a gaseous laser using blackbody radiation produced by a plasma channel which is formed from an electrical discharge between two electrodes spaced at opposite longitudinal ends of the laser. A preionization device which can comprise a laser or electron beam accelerator produces a preionization beam which is sufficient to cause an electrical discharge between the electrodes to initiate the plasma channel along the preionization path. The optical pumping energy is supplied by a high voltage power supply rather than by the preionization beam. High output optical intensities are produced by the laser due to the high temperature blackbody radiation produced by the plasma channel, in the same manner as an exploding wire type laser. However, unlike the exploding wire type laser, the disclosed invention can be operated in a repetitive manner by utilizing a repetitive pulsed preionization device. 5 figs.

Liquid crystal materials and tunable devices for optical communications

NASA Astrophysics Data System (ADS)

Du, Fang

In this dissertation, liquid crystal materials and devices are investigated in meeting the challenges for photonics and communications applications. The first part deals with polymer-stabilized liquid crystal (PSLC) materials and devices. Three polymer-stabilized liquid crystal systems are developed for optical communications. The second part reports the experimental investigation of a novel liquid-crystal-infiltrated photonic crystal fiber (PCF) and explores its applications in fiber-optic communications. The curing temperature is found to have significant effects on the PSLC performance. The electro-optic properties of nematic polymer network liquid crystal (PNLC) at different curing temperatures are investigated experimentally. At high curing temperature, a high contrast, low drive voltage, and small hysteresis PNLC is obtained as a result of the formed large LC microdomains. With the help of curing temperature effect, it is able to develop PNLC based optical devices with highly desirable performances for optical communications. Such high performance is generally considered difficult to realize for a PNLC. In fact, the poor performance of PNLC, especially at long wavelengths, has hindered it from practical applications for optical communications for a long time. Therefore, the optimal curing temperature effect discovered in this thesis would enable PSLCs for practical industrial applications. Further more, high birefringence LCs play an important role for near infrared photonic devices. The isothiocyanato tolane liquid crystals exhibit a high birefringence and low viscosity. The high birefringence LC dramatically improves the PSLC contrast ratio while keeping a low drive voltage and fast response time. A free-space optical device by PNLC is experimentally demonstrated and its properties characterized. Most LC devices are polarization sensitive. To overcome this drawback, we have investigated the polymer-stabilized cholesteric LC (PSCLC). Combining the curing

Micro-Fresnel Zone Plate Optical Devices Using Densely Accumulated Ray Points

NASA Technical Reports Server (NTRS)

Choi, Sang H. (Inventor); Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

2011-01-01

An embodiment generally relates to an optical device suitable for use with an optical medium for the storage and retrieval of data. The optical device includes an illumination means for providing a beam of optical radiation of wavelength .lamda. and an optical path that the beam of optical radiation follows. The optical device also includes a diffractive optical element defined by a plurality of annular sections. The plurality of annular sections having a first material alternately disposed with a plurality of annular sections comprising a second material. The diffractive optical element generates a plurality of focal points and densely accumulated ray points with phase contrast phenomena and the optical medium is positioned at a selected focal point or ray point of the diffractive optical element.

Handheld Sensor for UXO Discrimination:

DTIC Science & Technology

2006-06-01

between buried UXO and clutter. This project demonstrated the use of commercially available technology (Geonics EM61-HH handheld metal detector ) for...determine whether each target was UXO or clutter. The Geonics EM61-HH handheld metal detector is a pulsed electromagnetic induction (EMI) sensor. The...processing, the EM61-HH handheld metal detector can 2 be used in a cued identification mode to reliably discriminate between buried UXO and clutter

At Ease in the Handheld World.

ERIC Educational Resources Information Center

Levinson, Eliot; Grohe, Barbara

2001-01-01

Provides educational decision-makers with an overview of the offerings and issues related to adopting handheld computers. Describes several handheld products available to schools, including: Palm, iPAQ, Mindsurf, Symbol Technologies, Texas Instruments, and Gateway Handspring Visor. Compares handhelds to PCs, in terms of functionality, operating…

Multipass optical device and process for gas and analyte determination

DOEpatents

Bernacki, Bruce E [Kennewick, WA

2011-01-25

A torus multipass optical device and method are described that provide for trace level determination of gases and gas-phase analytes. The torus device includes an optical cavity defined by at least one ring mirror. The mirror delivers optical power in at least a radial and axial direction and propagates light in a multipass optical path of a predefined path length.

Deoxyribonucleic acid (DNA) cladding layers for nonlinear-optic-polymer-based electro-optic devices

NASA Astrophysics Data System (ADS)

Grote, James G.; Ogata, Naoya; Diggs, Darnell E.; Hopkins, Frank K.

2003-07-01

Nonlinear optic (NLO) polymer based electro-optic devices have been achieving world record low half wave voltages and high frequencies over the last 2-3 years. Part of the advancement is through the use of relatively more conductive polymers for the cladding layers. Based on the current materials available for these cladding materials, however, the desired optical and electromagnetic properites are being balanced for materials processability. One does not want the solvent present in one layer to dissovle the one deposited underneath, or be dissolved by the one being deposited on top. Optimized polymer cladding materials, to further enhance device performance, are continuing to be investigated. Thin films of deoxyribonucleic acid (DNA), derived from salmon sperm, show promise in providing both the desired optical and magnetic properties, as well as the desired resistance to various solvents used for NLO polymer device fabrication. Thin films of DNA were deposited on glass and silicon substrates and the film quality, optical and electromagnetic properties and resistance to various solvents were characterized.

A Mixed Methods Analysis of a Library Based Handheld Intervention with Rural Clinicians

PubMed Central

Wallace, Richard L.; Woodward, Nakia J.; Wolf, Katherine M.

2014-01-01

Background The East Tennessee State University Quillen College of Medicine Library has participated for several years in projects to provide rural clinicians with health information resources. Objectives To determine if a strategy of handheld devices with a best-evidence point-of-care disease tool and a drug database paired with access to a medical library for full-text articles and training to use the tools would be an affordable way to meet the information needs of rural underserved clinicians. Methods This study is a mixed methods methodology. The first project was evaluated using a randomized controlled trial (RCT) methodology. The second was evaluated qualitatively using interviews and focus groups. Results The quantitative findings discovered that clinicians equipped with a handheld device with evidence-based software more frequently found answers to clinical questions, found answers more quickly, were more satisfied with information they found, and use expensive resources such as continuing medical education, online databases, and textbooks less than the group that did not have access to online technology. Qualitative results supported the quantitative findings. Conclusion Librarians can implement a three-pronged strategy of the secondary literature via a handheld, the primary literature via LoansomeDoc, and quality training to meet basic information needs of rural clinicians. PMID:25155980

The optical properties of smoke-protective devices.

DOT National Transportation Integrated Search

1978-10-01

Optical properties of 13 smoke-protective devices were determined. The devices tested comprised 8 goggles and 5 fullface oxygen masks (3 rigid one-piece masks and 2 flexible hoods). Those properties evaluated were: (i) light transmission, (ii) optica...

Optical sensors and multisensor arrays containing thin film electroluminescent devices

DOEpatents

Aylott, Jonathan W.; Chen-Esterlit, Zoe; Friedl, Jon H.; Kopelman, Raoul; Savvateev, Vadim N.; Shinar, Joseph

2001-12-18

Optical sensor, probe and array devices for detecting chemical biological, and physical analytes. The devices include an analyte-sensitive layer optically coupled to a thin film electroluminescent layer which activates the analyte-sensitive layer to provide an optical response. The optical response varies depending upon the presence of an analyte and is detected by a photodetector and analyzed to determine the properties of the analyte.

The use of handheld spectral domain optical coherence tomography in pediatric ophthalmology practice: Our experience of 975 infants and children.

PubMed

Mallipatna, Ashwin; Vinekar, Anand; Jayadev, Chaitra; Dabir, Supriya; Sivakumar, Munsusamy; Krishnan, Narasimha; Mehta, Pooja; Berendschot, Tos; Yadav, Naresh Kumar

2015-07-01

Optical coherence tomography (OCT) is an important imaging tool assessing retinal architecture. In this article, we report a single centers experience of using handheld spectral domain (SD)-OCT in a pediatric population using the Envisu 2300 (Bioptigen Inc., Research Triangle Park, NC, USA). We studied SD-OCT images from 975 patients imaged from January 2011 to December 2014. The variety of cases that underwent an SD-OCT was analyzed. Cases examples from different case scenarios were selected to showcase unique examples of many diseases. Three hundred and sixty-eight infants (37.7%) were imaged for retinopathy of prematurity, 362 children (37.1%) underwent the test for evaluation of suboptimal vision or an unexplained vision loss, 126 children (12.9%) for evaluation of nystagmus or night blindness, 54 children (5.5%) for an intraocular tumor or a mass lesion such as retinoblastoma, and 65 children (6.7%) for other diseases of the pediatric retina. The unique findings in the retinal morphology seen with some of these diseases are discussed. The handheld SD-OCT is useful in the evaluation of the pediatric retinal diseases. The test is useful in the assessment of vision development in premature children, evaluation of unexplained vision loss and amblyopia, nystagmus and night blindness, and intraocular tumors (including retinoblastoma).

Quantum Optical Transistor and Other Devices Based on Nanostructures

NASA Astrophysics Data System (ADS)

Li, Jin-Jin; Zhu, Ka-Di

Laser and strong coupling can coexist in a single quantum dot (QD) coupled to nanostructures. This provides an important clue toward the realization of quantum optical devices, such as quantum optical transistor, slow light device, fast light device, or light storage device. In contrast to conventional electronic transistor, a quantum optical transistor uses photons as signal carriers rather than electrons, which has a faster and more powerful transfer efficiency. Under the radiation of a strong pump laser, a signal laser can be amplified or attenuated via passing through a single quantum dot coupled to a photonic crystal (PC) nanocavity system. Such a switching and amplifying behavior can really implement the quantum optical transistor. By simply turning on or off the input pump laser, the amplified or attenuated signal laser can be obtained immediately. Based on this transistor, we further propose a method to measure the vacuum Rabi splitting of exciton in all-optical domain. Besides, we study the light propagation in a coupled QD and nanomechanical resonator (NR) system. We demonstrate that it is possible to achieve the slow light, fast light, and quantum memory for light on demand, which is based on the mechanically induced coherent population oscillation (MICPO) and exciton polaritons. These QD devices offer a route toward the use of all-optical technique to investigate the coupled QD systems and will make contributions to quantum internets and quantum computers.

The liquid crystal light valve, an optical-to-optical interface device

NASA Technical Reports Server (NTRS)

Jacobson, A. D.; Beard, T. D.; Bleha, W. P.; Margerum, J. D.; Wong, S. Y.

1972-01-01

A photoactivated liquid crystal light valve is described as an optical-to-optical interface device (OTTO) which is designed to transfer an optical image from a noncoherent light beam to a spatially coherent beam of light, in real time. Schematics of OTTO in use, the liquid cyrstal cell, and the liquid crystal structure are presented. Sensitivity characteristics and the principles of operation are discussed.

A handheld laser-induced fluorescence detector for multiple applications.

PubMed

Fang, Xiao-Xia; Li, Han-Yang; Fang, Pan; Pan, Jian-Zhang; Fang, Qun

2016-04-01

In this paper, we present a compact handheld laser-induced fluorescence (LIF) detector based on a 450 nm laser diode and quasi-confocal optical configuration with a total size of 9.1 × 6.2 × 4.1 cm(3). Since there are few reports on the use of 450 nm laser diode in LIF detection, especially in miniaturized LIF detector, we systematically investigated various optical arrangements suitable for the requirements of 450 nm laser diode and system miniaturization, including focusing lens, filter combination, and pinhole, as well as Raman effect of water at 450 nm excitation wavelength. As the result, the handheld LIF detector integrates the light source (450 nm laser diode), optical circuit module (including a 450 nm band-pass filter, a dichroic mirror, a collimating lens, a 525 nm band-pass filter, and a 1.0mm aperture), optical detector (miniaturized photomultiplier tube), as well as electronic module (including signal recording, processing and displaying units). This detector is capable of working independently with a cost of ca. $2000 for the whole instrument. The detection limit of the instrument for sodium fluorescein solution is 0.42 nM (S/N=3). The broad applicability of the present system was demonstrated in capillary electrophoresis separation of fluorescein isothiocyanate (FITC) labeled amino acids and in flow cytometry of tumor cells as an on-line LIF detector, as well as in droplet array chip analysis as a LIF scanner. We expect such a compact LIF detector could be applied in flow analysis systems as an on-line detector, and in field analysis and biosensor analysis as a portable universal LIF detector. Copyright © 2015 Elsevier B.V. All rights reserved.

Device having two optical ports for switching applications

DOEpatents

Rosen, Ayre; Stabile, Paul J.

1991-09-24

A two-sided light-activatable semiconductor switch device having an optical port on each side thereof. The semiconductor device may be a p-i-n diode or of bulk intrinsic material. A two ported p-i-n diode, reverse-biased to "off" by a 1.3 kV dc power supply, conducted 192 A when activated by two 1 kW laser diode arrays, one for each optical port.

Optical system for object detection and delineation in space

NASA Astrophysics Data System (ADS)

Handelman, Amir; Shwartz, Shoam; Donitza, Liad; Chaplanov, Loran

2018-01-01

Object recognition and delineation is an important task in many environments, such as in crime scenes and operating rooms. Marking evidence or surgical tools and attracting the attention of the surrounding staff to the marked objects can affect people's lives. We present an optical system comprising a camera, computer, and small laser projector that can detect and delineate objects in the environment. To prove the optical system's concept, we show that it can operate in a hypothetical crime scene in which a pistol is present and automatically recognize and segment it by various computer-vision algorithms. Based on such segmentation, the laser projector illuminates the actual boundaries of the pistol and thus allows the persons in the scene to comfortably locate and measure the pistol without holding any intermediator device, such as an augmented reality handheld device, glasses, or screens. Using additional optical devices, such as diffraction grating and a cylinder lens, the pistol size can be estimated. The exact location of the pistol in space remains static, even after its removal. Our optical system can be fixed or dynamically moved, making it suitable for various applications that require marking of objects in space.

Bi-stable optical element actuator device

DOEpatents

Holdener, Fred R.; Boyd, Robert D.

2002-01-01

The present invention is a bistable optical element actuator device utilizing a powered means to move an actuation arm, to which an optical element is attached, between two stable positions. A non-powered means holds the actuation arm in either of the two stable positions. The optical element may be a electromagnetic (EM) radiation or particle source, an instrument, or EM radiation or particle transmissive reflective or absorptive elements. A bearing is used to transfer motion and smoothly transition the actuation arm between the two stable positions.

OPTOELECTRONICS, FIBER OPTICS, AND OTHER ASPECTS OF QUANTUM ELECTRONICS: Nonlinear optical devices: basic elements of a future optical digital computer?

NASA Astrophysics Data System (ADS)

Fischer, R.; Müller, R.

1989-08-01

It is shown that nonlinear optical devices are the most promising elements for an optical digital supercomputer. The basic characteristics of various developed nonlinear elements are presented, including bistable Fabry-Perot etalons, interference filters, self-electrooptic effect devices, quantum-well devices utilizing transitions between the lowest electron states in the conduction band of GaAs, etc.

Optical imaging for breast cancer prescreening

PubMed Central

Godavarty, Anuradha; Rodriguez, Suset; Jung, Young-Jin; Gonzalez, Stephanie

2015-01-01

Breast cancer prescreening is carried out prior to the gold standard screening using X-ray mammography and/or ultrasound. Prescreening is typically carried out using clinical breast examination (CBE) or self-breast examinations (SBEs). Since CBE and SBE have high false-positive rates, there is a need for a low-cost, noninvasive, non-radiative, and portable imaging modality that can be used as a prescreening tool to complement CBE/SBE. This review focuses on the various hand-held optical imaging devices that have been developed and applied toward early-stage breast cancer detection or as a prescreening tool via phantom, in vivo, and breast cancer imaging studies. Apart from the various optical devices developed by different research groups, a wide-field fiber-free near-infrared optical scanner has been developed for transillumination-based breast imaging in our Optical Imaging Laboratory. Preliminary in vivo studies on normal breast tissues, with absorption-contrasted targets placed in the intramammary fold, detected targets as deep as 8.8 cm. Future work involves in vivo imaging studies on breast cancer subjects and comparison with the gold standard X-ray mammography approach. PMID:26229503

Exploring Novel Crystals and Designs for Acousto-Optic Devices

NASA Astrophysics Data System (ADS)

Pfeiffer, Jonathan B.

Acousto-optic devices are a versatile technology that are driven electronically to precisely and rapidly control the intensity, frequency, and propagation direction of a laser beam. Applications include acousto-optic scanners, filters, mode lockers, and modulators. Despite the popularity of acousto-optic devices, there currently is no UV transparent device that can satisfy the requirements of the atomic clock and quantum computing communities. In this thesis, I describe my experimental efforts for discovering a new UV transparent, acousto-optic crystal that can meet the experimental requirements. I also present my graphical representations for locating practical and efficient acousto-optic designs in a given medium. The first part of this thesis describes how to measure the elastic-stiffness and photoelastic coefficients of a given crystal. The elastic-stiffness coefficients are essential for designing acousto-optic devices because they determine the velocity, diffraction, and polarization of acoustic waves in a given medium. I used both resonant ultrasound spectroscopy and a modified version of Schaefer-Bergman diffraction to measure elastic coefficients. I discuss in detail the strengths, differences, and similarities of the two experiments. The photoelastic coefficients are necessary for determining the diffraction efficiency of a given acousto-optic geometry. Similar to the elastic coefficients, I employ a modified version of the Schaefer-Bergmann experiment to measure the photoelastic coefficients. I corroborate the measured results with the well established Dixon experiment. The second part of this thesis describes four different graphical representations that help locate practical and efficient acousto-optic designs. I describe in detail each algorithm and how to interpret the calculated results. Several examples are provided for commonly used acosuto-optic materials. The thesis concludes by describing the design and performance of an acousto-optic frequency

Thresholds of whole-blood β-hydroxybutyrate and glucose concentrations measured with an electronic hand-held device to identify ovine hyperketonemia.

PubMed

Pichler, M; Damberger, A; Schwendenwein, I; Gasteiner, J; Drillich, M; Iwersen, M

2014-03-01

Metabolic disorders, especially hyperketonemia, are very common in dairy sheep. The whole-blood concentrations of β-hydroxybutyrate (BHBA) and glucose can be determined by commercially available electronic hand-held devices, which are used in human medicine and for the detection of ketosis in dairy cows. The aim of this study was to evaluate the suitability of the hand-held device Precision Xceed (PX; Abbott Diabetes Care Inc., Abbott Park, IL) to detect hyperketonemia in ewes. An additional objective of this study was to evaluate the agreement between samples obtained by minimal invasive venipuncture of an ear vein and measurements of whole-blood samples from the jugular vein (vena jugularis, v. jug.). Blood samples taken from the v. jug. were collected from 358 ewes on 4 different farms. These samples and a blood drop obtained from an ear vein were analyzed simultaneously on farm with the PX. For method comparison, the samples obtained from the v. jug. were also analyzed by standard methods, which served as the gold standard at the Central Laboratory of the University of Veterinary Medicine Vienna, Austria. The correlation coefficients between the serum BHBA concentration and the concentrations measured with the hand-held meter in the whole blood from an ear vein and the v. jug. were 0.94 and 0.96, respectively. The correlation coefficients of plasma and whole-blood glucose concentration were 0.68 for the v. jug. and 0.47 for the ear vein. The mean glucose concentration was significantly lower in animals classified as hyperketonemic (BHBA ≥ 1.6 mmol/L) compared with healthy ewes. Whole-blood concentrations of BHBA and glucose measured with the PX from v. jug. showed a constant negative bias of 0.15 mmol/L and 8.4 mg/dL, respectively. Hence, a receiver operating characteristic analysis was performed to determine thresholds for the PX to detect hyperketonemia in ewes. This resulted in thresholds for moderate ketosis of BHBA concentrations of 0.7 mmol/L in blood

Printed Biopolymer-Based Electro-Optic Device Components

DTIC Science & Technology

2013-07-01

devices and fabricated e-beam lithography-based master molds. Printed micro and nanostructures using a newly developed spin-on nanoprinting (SNAP...polymeric materials. Among the natural biopolymers , deoxyribonucleic acid (DNA) is an attractive material which can be used to make electronic and...photonic devices [2, 3]. If patterned on the micro and nanoscale using a soft lithography technique, high quality biodegradable optical devices can be

Two position optical element actuator device

DOEpatents

Holdener, Fred R.; Boyd, Robert D.

2002-01-01

The present invention is a two position optical element actuator device utilizing a powered means to hold an actuation arm, to which an optical element is attached, in a first position. A non-powered means drives the actuation arm to a second position, when the powered means ceases to receive power. The optical element may be a electromagnetic (EM) radiation or particle source, an instrument, or EM radiation or particle transmissive, reflective or absorptive elements. A bearing is used to transfer motion and smoothly transition the actuation arm from the first to second position.

An Inexpensive Optical Absorption Experiment

NASA Astrophysics Data System (ADS)

Greenslade, Thomas B.

2006-09-01

This optical absorption experiment can be put together in only a few minutes with materials found in most secondary or undergraduate stockrooms. The absorption material is the partly transparent flexible anti-static plastic material used to package solid-state devices. The detector is a hand-held photographic exposure meter of the type that was in common use before the advent of point-and-shoot cameras. A graph of the intensity of the transmitted light as a function of the number of sheets of the material is a decreasing exponential. The emphasis of the experiment is on the mathematical form.

Energy Cost of Active and Sedentary Music Video Games: Drum and Handheld Gaming vs. Walking and Sitting

PubMed Central

MIRANDA, EDWIN; OVERSTREET, BRITTANY S.; FOUNTAIN, WILLIAM A.; GUTIERREZ, VINCENT; KOLANKOWSKI, MICHAEL; OVERSTREET, MATTHEW L.; SAPP, RYAN M.; WOLFF, CHRISTOPHER A.; MAZZETTI, SCOTT A.

2017-01-01

To compare energy expenditure during and after active and handheld video game drumming compared to walking and sitting. Ten experienced, college-aged men performed four protocols (one per week): no-exercise seated control (CTRL), virtual drumming on a handheld gaming device (HANDHELD), active drumming on drum pads (DRUM), and walking on a treadmill at ~30% of VO2max (WALK). Protocols were performed after an overnight fast, and expired air was collected continuously during (30min) and after (30min) exercise. DRUM and HANDHELD song lists, day of the week, and time of day were identical for each participant. Significant differences (p < 0.05) among the average rates of energy expenditure (kcal·min−1) during activity included WALK > DRUM > HANDHELD. No significant differences in the rates of energy expenditure among groups during recovery were observed. Total energy expenditure was significantly greater (p < 0.05) during WALK (149.5 ± 30.6 kcal) compared to DRUM (118.7 ± 18.8 kcal) and HANDHELD (44.9±11.6 kcal), and greater during DRUM compared to HANDHELD. Total energy expenditure was not significantly different between HANDHELD (44.9 ± 11.6 kcal) and CTRL (38.2 ± 6.0 kcal). Active video game drumming at expert-level significantly increased energy expenditure compared to handheld, but it hardly met moderate-intensity activity standards, and energy expenditure was greatest during walking. Energy expenditure with handheld video game drumming was not different from no-exercise control. Thus, traditional aerobic exercise remains at the forefront for achieving the minimum amount and intensity of physical activity for health, individuals desiring to use video games for achieving weekly physical activity recommendations should choose games that require significant involvement of lower-body musculature, and time spent playing sedentary games should be a limited part of an active lifestyle. PMID:29170705

Energy Cost of Active and Sedentary Music Video Games: Drum and Handheld Gaming vs. Walking and Sitting.

PubMed

Miranda, Edwin; Overstreet, Brittany S; Fountain, William A; Gutierrez, Vincent; Kolankowski, Michael; Overstreet, Matthew L; Sapp, Ryan M; Wolff, Christopher A; Mazzetti, Scott A

2017-01-01

To compare energy expenditure during and after active and handheld video game drumming compared to walking and sitting. Ten experienced, college-aged men performed four protocols (one per week): no-exercise seated control (CTRL), virtual drumming on a handheld gaming device (HANDHELD), active drumming on drum pads (DRUM), and walking on a treadmill at ~30% of VO 2max (WALK). Protocols were performed after an overnight fast, and expired air was collected continuously during (30min) and after (30min) exercise. DRUM and HANDHELD song lists, day of the week, and time of day were identical for each participant. Significant differences (p < 0.05) among the average rates of energy expenditure (kcal·min -1 ) during activity included WALK > DRUM > HANDHELD. No significant differences in the rates of energy expenditure among groups during recovery were observed. Total energy expenditure was significantly greater (p < 0.05) during WALK (149.5 ± 30.6 kcal) compared to DRUM (118.7 ± 18.8 kcal) and HANDHELD (44.9±11.6 kcal), and greater during DRUM compared to HANDHELD. Total energy expenditure was not significantly different between HANDHELD (44.9 ± 11.6 kcal) and CTRL (38.2 ± 6.0 kcal). Active video game drumming at expert-level significantly increased energy expenditure compared to handheld, but it hardly met moderate-intensity activity standards, and energy expenditure was greatest during walking. Energy expenditure with handheld video game drumming was not different from no-exercise control. Thus, traditional aerobic exercise remains at the forefront for achieving the minimum amount and intensity of physical activity for health, individuals desiring to use video games for achieving weekly physical activity recommendations should choose games that require significant involvement of lower-body musculature, and time spent playing sedentary games should be a limited part of an active lifestyle.

Hand-held optical fuel pin scanner

DOEpatents

Kirchner, T.L.; Powers, H.G.

1980-12-07

An optical scanner for indicia arranged in a focal plane perpendicular to an optical system including a rotatable dove prism. The dove prism transmits a rotating image to a stationary photodiode array.

Hand-held optical fuel pin scanner

DOEpatents

Kirchner, Tommy L.; Powers, Hurshal G.

1987-01-01

An optical scanner for indicia arranged in a focal plane perpendicular to an optical system including a rotatable dove prism. The dove prism transmits a rotating image to a stationary photodiode array.

Optical interconnection for a polymeric PLC device using simple positional alignment.

PubMed

Ryu, Jin Hwa; Kim, Po Jin; Cho, Cheon Soo; Lee, El-Hang; Kim, Chang-Seok; Jeong, Myung Yung

2011-04-25

This study proposes a simple cost-effective method of optical interconnection between a planar lightwave circuit (PLC) device chip and an optical fiber. It was conducted to minimize and overcome the coupling loss caused by lateral offset which is due to the process tolerance and the dimensional limitation existing between PLC device chips and fiber array blocks with groove structures. A PLC device chip and a fiber array block were simultaneously fabricated in a series of polymer replication processes using the original master. The dimensions (i.e., width and thickness) of the under-clad of the PLC device chip were identical to those of the fiber array block. The PLC device chip and optical fiber were aligned by simple positional control for the vertical direction of the PLC device chip under a particular condition. The insertion loss of the proposed 1 x 2 multimode optical splitter device interconnection was 4.0 dB at 850 nm and the coupling loss was below 0.1 dB compared with single-fiber based active alignment.

Synthetic-lattice enabled all-optical devices based on orbital angular momentum of light.

PubMed

Luo, Xi-Wang; Zhou, Xingxiang; Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can; Zhang, Chuanwei; Zhou, Zheng-Wei

2017-07-14

All-optical photonic devices are crucial for many important photonic technologies and applications, ranging from optical communication to quantum information processing. Conventional design of all-optical devices is based on photon propagation and interference in real space, which may rely on large numbers of optical elements, and the requirement of precise control makes this approach challenging. Here we propose an unconventional route for engineering all-optical devices using the photon's internal degrees of freedom, which form photonic crystals in such synthetic dimensions for photon propagation and interference. We demonstrate this design concept by showing how important optical devices such as quantum memory and optical filters can be realized using synthetic orbital angular momentum (OAM) lattices in degenerate cavities. The design route utilizing synthetic photonic lattices may significantly reduce the requirement for numerous optical elements and their fine tuning in conventional design, paving the way for realistic all-optical photonic devices with novel functionalities.

Synthetic-lattice enabled all-optical devices based on orbital angular momentum of light

PubMed Central

Luo, Xi-Wang; Zhou, Xingxiang; Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can; Zhang, Chuanwei; Zhou, Zheng-Wei

2017-01-01

All-optical photonic devices are crucial for many important photonic technologies and applications, ranging from optical communication to quantum information processing. Conventional design of all-optical devices is based on photon propagation and interference in real space, which may rely on large numbers of optical elements, and the requirement of precise control makes this approach challenging. Here we propose an unconventional route for engineering all-optical devices using the photon’s internal degrees of freedom, which form photonic crystals in such synthetic dimensions for photon propagation and interference. We demonstrate this design concept by showing how important optical devices such as quantum memory and optical filters can be realized using synthetic orbital angular momentum (OAM) lattices in degenerate cavities. The design route utilizing synthetic photonic lattices may significantly reduce the requirement for numerous optical elements and their fine tuning in conventional design, paving the way for realistic all-optical photonic devices with novel functionalities. PMID:28706215

Patient Perceptions of Physician Use of Handheld Computers

PubMed Central

Houston, Thomas K.; Ray, Midge N.; Crawford, Myra A.; Giddens, Tonya; Berner, Eta S.

2003-01-01

Background Handheld computers have advantages for physicians, including portability and integration into office workflow. However, negative patient perceptions of physician use of handheld computers in the examining room might limit integration. Objective To survey patients’ perceptions of handheld use, and compare those with their providers’ perceptions. Methods A survey of patient attitudes toward handhelds was conducted among patients at a low-income university clinic. Internal Medicine residents providing care were also surveyed. Results Patients (N=93) were mostly female (79%) and ethnic minorities (67%) with average age of 39. Only 10% of patients did not like the idea of a handheld computer in the exam room. Other negative attitudes were also seen in a minority of patients. Some physicians (23%) reported reservations about using the handheld with patients. Conclusions Negative attitudes were rare among patients, but some providers were concerned about using the handheld in the exam room. PMID:14728182

Analysis of Peer Interaction in Learning Activities with Personal Handhelds and Shared Displays

ERIC Educational Resources Information Center

Liu, Chen-Chung; Chung, Chen-Wei; Chen, Nian-Shing; Liu, Baw-Jhiune

2009-01-01

Collaborative learning is extensively applied in classroom activities, but the screens on handheld devices are designed for individual-user mobile applications and may constrain interaction among group learners. The small screen size may lead to fragmented and tete-a-tete communication patterns and frequently obstruct the externalization of the…

Justification and good practice in using handheld portable dental X-ray equipment: a position paper prepared by the European Academy of DentoMaxilloFacial Radiology (EADMFR)

PubMed Central

Suomalainen, A; Brüllmann, D; Jacobs, R; Horner, K; Stamatakis, H C

2015-01-01

Handheld portable X-ray devices are increasingly used for intraoral radiography. This development introduces new challenges to staff and patient safety, for which new or revised risk assessments must be made and acted upon prior to use. Major issues might be: difficulties in using rectangular collimation with beam aiming devices, more complex matching of exposure settings to the X-ray receptor used (e.g. longer exposure times), movements owing to the units' weight, protection of the operator and third persons, and the use in uncontrolled environments. These problems may result in violation of the “as low as reasonably achievable’’, that is, ALARA principle by an increase in (re)exposures compared with the other available intraoral X-ray devices. Hence, the use of handheld portable X-ray devices should be considered only after careful and documented evaluation (which might be performed based on medical physics support), when there is evidence that handheld operation has benefits over traditional modalities and when no new risks to the operators and/or third parties are caused. It is expected that the use of handheld portable X-ray devices will be very exceptional, and for justified situations only. Special attention should be drawn to beam-aiming devices, rectangular collimation, the section of the X-ray receptor, focus–skin distance, and backscatter shielding, and that the unit delivers reproducible dose over the full set of environmental conditions (e.g. battery status and temperature). PMID:25710118

Home-based wrinkle reduction using a novel handheld multisource phase-controlled radiofrequency device.

PubMed

Shemer, Avner; Levy, Hanna; Sadick, Neil S; Harth, Yoram; Dorizas, Andrew S

2014-11-01

In the last decade, energy-based aesthetic treatments, using light, radiofrequency (RF), and ultrasound, have gained scientific acceptance as safe and efficacious for non-invasive treatment for aesthetic skin disorders. The phase-controlled multisource radiofrequency technology (3DEEP™), which is based on the simultaneous use of multiple RF generators, was proven to allow significant pigment-independent dermal heating without pain or the need of epidermal cooling. This study was performed in order to evaluate the efficacy and safety of a new handheld device delivering multisource radiofrequency to the skin for wrinkle reduction and skin tightening in the home setting. A total of 69 participants (age 54.3 years ± 8.09; age range 37-72 years) were enrolled in the study after meeting all inclusion/exclusion criteria (100%) and providing informed consent. Participants were provided with the tested device together with a user manual and treatment diary, to perform independent treatments at home for 4 weeks. The tested device, (Newa™, EndyMed Medical, Cesarea, Israel) emits 12 W of 1Mhz, RF energy through six electrodes arranged in a linear fashion. Independent control of RF polarity through each one of the 6 electrodes allows significant reduction of energy flow through the epidermis with increased dermal penetration. Participants were instructed to perform at least 5 treatments a week, for one month. Four follow-up visits were scheduled (once a week) during the period of independent treatments at home, following 4 weeks of home treatments, 1 month follow-up visit (1 month after treatment end) and at 3 months follow-up (3 months following treatment end). Analysis of pre-and post treatment images was conducted by three uninvolved physicians experienced with the Fitzpatrick Wrinkle and Elastosis Scale. Fitzpatrick Wrinkle and Elastosis score of each time point (4 weeks following home use treatments; 1 month follow-up, 3 months follow-up) was compared to baseline

Electro-optic studies of novel organic materials and devices

NASA Astrophysics Data System (ADS)

Xu, Jianjun

1997-11-01

Specific single crystal organic materials have high potential for use in high speed optical signal processing and various other electro-optic applications. In this project some of the most important organic crystal materials were studied regarding their detailed electro- optic properties and potential device applications. In particular, the electro-optic properties of N-(4- Nitrophenyl)-L-Prolinol (NPP) and 4'-N,N- dimethylamino-4-methylstilbazolium tosylate (DAST) both of which have extremely large second order susceptibilites were studied. The orientation of the thin film crystal with respect to the substrate surface was determined using-X-ray diffraction. The principal axes of the single crystal thin film were determined by polarization transmission microscopy. The elements of the electro-optic coefficient tensor were measured by field induced birefringence measurements. Detailed measurements for NPP thin films with different orientations of the external electric field with respect to the charge transfer axis were carried out at a wavelength of 1064nm. The wavelength dependence of the electro-optic effect for DAST single crystal thin films was measured using a Ti:Sapphire laser. Several device geometries involving organic single crystal thin film materials were studied. A new method for the fabrication of channel waveguides for organic materials was initiated. Channel waveguides for NPP and ABP were obtained using this methods. Optical modulation due to the electro-optic effect based on the organic channel waveguide for NPP single crystal was demonstrated. The electro-optic modulation using NPP single crystals thin film in a Fabry-Perot cavity was measured. A device using a optical fiber half coupler and organic electro-optic thin film material was constructed, and it has potential applications in optical signal processing.

Hand-Held Color Meters Based on Interference Filters

NASA Technical Reports Server (NTRS)

Snyder, G. Jeffrey; Fleurial, Jean-Pierre; Caillat, Thierry; Chen, Gang; Yang, Rong Gui

2004-01-01

Small, inexpensive, hand-held optoelectronic color-measuring devices based on metal-film/dielectric-film interference filters are undergoing development. These color meters could be suitable for use in a variety of applications in which there are requirements to quantify or match colors for aesthetic purposes but there is no need for the high spectral resolution of scientific-grade spectrometers. Such applications typically occur in the paint, printing, and cosmetic industries, for example. The figure schematically depicts a color meter of this type being used to measure the color of a sample in terms of the spectrum of light reflected from the sample. Light from a white source (for example, a white light-emitting diode) passes through a collimating lens to the sample. Another lens collects some of the light reflected from the sample and focuses the light onto the input end of optical fiber. Light emerging from the output end of the optical fiber illuminates an array of photodetectors covered with metal/dielectric-film interference filters like those described in Metal/Dielectric-film Interference Color Filters (NPO-20217), NASA Tech Briefs, Vol. 23, No. 2 (February 1999), page 70. Typically, these are wide-band-pass filters, as shown at the bottom of the figure. The photodetector array need not be of any particular design: it could be something as simple as an assembly containing several photodiodes or something as elaborate as an active-pixel sensor or other imaging device. What is essential is that each of the photodetectors or each of several groups of photodetectors is covered with a metal/dielectric-film filter of a different color. In most applications, it would be desirable to have at least three different filters, each for a spectral band that contains one of the three primary additive red, green, and blue colors. In some applications, it may be necessary to have more than three different color filters in order to characterize subtle differences in color

Monitoring of WEEE plastics in regards to brominated flame retardants using handheld XRF.

PubMed

Aldrian, Alexia; Ledersteger, Alfred; Pomberger, Roland

2015-02-01

This contribution is focused on the on-site determination of the bromine content in waste electrical and electronic equipment (WEEE), in particular waste plastics from television sets (TV) and personal computer monitors (PC) using a handheld X-ray fluorescence (XRF) device. The described approach allows the examination of samples in regards to the compliance with legal specifications for polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) directly after disassembling and facilitates the sorting out of plastics with high contents of brominated flame retardants (BFRs). In all, over 3000 pieces of black (TV) and 1600 pieces of grey (PC) plastic waste were analysed with handheld XRF technique for this study. Especially noticeable was the high percentage of pieces with a bromine content of over 50,000ppm for TV (7%) and PC (39%) waste plastics. The applied method was validated by comparing the data of handheld XRF with results obtained by GC-MS. The results showed the expected and sufficiently accurate correlation between these two methods. It is shown that handheld XRF technique is an effective tool for fast monitoring of large volumes of WEEE plastics in regards to BFRs for on-site measurements. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hand-held photomicroscope

NASA Technical Reports Server (NTRS)

Zabower, H. R. (Inventor)

1973-01-01

A small, lightweight, compact, hand-held photomicroscope provides simultaneous viewing and photographing, with adjustable specimen illumination and exchangeable camera format. The novel photomicroscope comprises a main housing having a top plate, bottom plate, and side walls. The objective lens is mounted on the top plate in an inverted manner relative to the normal type of mounting. The specimen holder has an adjusting mechanism for adjustably moving the specimen vertically along an axis extending through the objective lens as well as transverse of the axis. The lens system serves to split the beam of light into two paths, one to the eyepiece and the other to a camera mounting. A light source is mounted on the top plate and directs light onto the specimen. A rheostat device is mounted on the top plate and coupled to the power supply for the light source so that the intensity of the light may be varied.

Hand-held triangulation laser profilometer with audio output for blind people Profilométre laser à triangulation tenu en main avec sortie sonare pour non-voyants

NASA Astrophysics Data System (ADS)

Farcy, R.; Damaschini, R.

1998-06-01

We describe a device currently under industrial development which will give to the blind a means of three-dimensional space perception. It consists of a 350 g hand-held triangulating laser telemeter including electronic parts and batteries, with auditory feedback either inside the apparatus or close to the ear. The microprocessor unit converts in real time the distance measured by the telemeter into a musical note. Scanning the space with an adequate movement of the hand produces musical lines corresponding to the profiles of the environment. We discuss the optical configuration of the system relative to our first year of clinical experimentation.

Measurement of β-hydroxybutyrate in capillary blood obtained from an ear to detect hyperketonemia in dairy cows by using an electronic handheld device.

PubMed

Süss, D; Drillich, M; Klein-Jöbstl, D; Wagener, K; Krieger, S; Thiel, A; Meyer, L; Schwendenwein, I; Iwersen, M

2016-09-01

The primary objective of the present study was to test whether capillary blood obtained by puncturing the skin of an ear with a minimal invasive lancet technique is able to detect hyperketonemia (HYK) in dairy cows. Furthermore, test characteristics of a new available handheld device, the FreeStyle Precision Neo (FSP-Neo, Abbott GmbH & Co. KG, Wiesbaden, Germany) for determination of β-hydroxybutyrate (BHB) concentrations in bovine blood were evaluated by comparing the measurements with a laboratory reference. The BHB concentration was determined with the FSP-Neo device in 720 capillary blood samples from 3 different sampling sites (left, right ear, and repeated measurement) and in 240 samples from a coccygeal vessel. The concentration of BHB in serum harvested from the coccygeal blood samples was analyzed at the laboratory and was used as reference. The Spearman correlation coefficient (ρs) between the BHB concentrations in capillary blood measured with the handheld device and the reference test was between 0.76 and 0.81. Using capillary blood, the mean ± standard deviation BHB difference compared with the reference test was 0.20±0.47 mmol/L for all 3 sampling locations at the ears. The receiver operating characteristic analyses for the FSP-Neo device resulted in an optimized threshold for the detection of subclinical ketosis (SCK) in capillary blood of 1.3 mmol/L (left and right ear) and 1.2 mmol/L (repeated measurements). Applying these adjusted threshold sensitivities (Se) for all 3 capillary sampling sites at the ear were 100%, and specificities (Sp) ranged between 93 and 94%. Hence, we conclude that all sampling locations were suitable to identify cows suffering from SCK. The reference test compared with BHB measurements in coccygeal blood resulted in a ρs of 0.92 with a mean ± standard deviation of 0.02±0.21 mmol/L. The receiver operating characteristic analyses for the FSP-Neo device resulted in an optimized threshold for the detection of SCK in

Handheld pose tracking using vision-inertial sensors with occlusion handling

NASA Astrophysics Data System (ADS)

Li, Juan; Slembrouck, Maarten; Deboeverie, Francis; Bernardos, Ana M.; Besada, Juan A.; Veelaert, Peter; Aghajan, Hamid; Casar, José R.; Philips, Wilfried

2016-07-01

Tracking of a handheld device's three-dimensional (3-D) position and orientation is fundamental to various application domains, including augmented reality (AR), virtual reality, and interaction in smart spaces. Existing systems still offer limited performance in terms of accuracy, robustness, computational cost, and ease of deployment. We present a low-cost, accurate, and robust system for handheld pose tracking using fused vision and inertial data. The integration of measurements from embedded accelerometers reduces the number of unknown parameters in the six-degree-of-freedom pose calculation. The proposed system requires two light-emitting diode (LED) markers to be attached to the device, which are tracked by external cameras through a robust algorithm against illumination changes. Three data fusion methods have been proposed, including the triangulation-based stereo-vision system, constraint-based stereo-vision system with occlusion handling, and triangulation-based multivision system. Real-time demonstrations of the proposed system applied to AR and 3-D gaming are also included. The accuracy assessment of the proposed system is carried out by comparing with the data generated by the state-of-the-art commercial motion tracking system OptiTrack. Experimental results show that the proposed system has achieved high accuracy of few centimeters in position estimation and few degrees in orientation estimation.

A quantum optical firewall based on simple quantum devices

NASA Astrophysics Data System (ADS)

Amellal, H.; Meslouhi, A.; Hassouni, Y.; El Baz, M.

2015-07-01

In order to enhance the transmission security in quantum communications via coherent states, we propose a quantum optical firewall device to protect a quantum cryptosystem against eavesdropping through optical attack strategies. Similar to the classical model of the firewall, the proposed device gives legitimate users the possibility of filtering, controlling (input/output states) and making a decision (access or deny) concerning the traveling states. To prove the security and efficiency of the suggested optical firewall, we analyze its performances against the family of intercept and resend attacks, especially against one of the most prominent attack schemes known as "Faked State Attack."

Comparison of handheld computer-assisted and conventional paper chart documentation of medical records. A randomized, controlled trial.

PubMed

Stengel, Dirk; Bauwens, Kai; Walter, Martin; Köpfer, Thilo; Ekkernkamp, Axel

2004-03-01

Daily documentation and maintenance of medical record quality is a crucial issue in orthopaedic surgery. The purpose of the present study was to determine whether the introduction of a handheld computer could improve both the quantitative and qualitative aspects of medical records. A series of consecutive patients who were admitted for the first time to a thirty-six-bed orthopaedic ward of an academic teaching hospital for a planned operation or any other treatment of an acute injury or chronic condition were randomized to daily documentation of their clinical charts on a handheld computer or on conventional paper forms. The electronic documentation consisted of a specially designed software package on a handheld computer for bedside use with structured decision trees for examination, obtaining a history, and coding. In the control arm, chart notes were compiled on standard paper forms and were subsequently entered into the hospital's information system. The number of documented ICD (International Classification of Diseases) diagnoses was the primary end point for sample size calculations. All patient charts were reread by an expert panel consisting of two surgeons and the surgical quality assurance manager. These experts assigned quality ratings to the different documentation systems by scrutinizing the extent and accuracy of the patient histories and the physical findings as assessed by daily chart notes. Eighty patients were randomized to one of the two documentation arms, and seventy-eight (forty-seven men and thirty-one women) of them were eligible for final analysis. Documentation with the handheld computer increased the median number of diagnoses per patients from four to nine (p < 0.0001), but it produced some overcoding for false or redundant items. Documentation quality ratings improved significantly with the introduction of the handheld device (p < 0.01) with respect to the correct assessment of a patient's progress and translation into ICD diagnoses

Smartphone based hand-held quantitative phase microscope using the transport of intensity equation method.

PubMed

Meng, Xin; Huang, Huachuan; Yan, Keding; Tian, Xiaolin; Yu, Wei; Cui, Haoyang; Kong, Yan; Xue, Liang; Liu, Cheng; Wang, Shouyu

2016-12-20

In order to realize high contrast imaging with portable devices for potential mobile healthcare, we demonstrate a hand-held smartphone based quantitative phase microscope using the transport of intensity equation method. With a cost-effective illumination source and compact microscope system, multi-focal images of samples can be captured by the smartphone's camera via manual focusing. Phase retrieval is performed using a self-developed Android application, which calculates sample phases from multi-plane intensities via solving the Poisson equation. We test the portable microscope using a random phase plate with known phases, and to further demonstrate its performance, a red blood cell smear, a Pap smear and monocot root and broad bean epidermis sections are also successfully imaged. Considering its advantages as an accurate, high-contrast, cost-effective and field-portable device, the smartphone based hand-held quantitative phase microscope is a promising tool which can be adopted in the future in remote healthcare and medical diagnosis.

Integrated-optic current sensors with a multimode interference waveguide device.

PubMed

Kim, Sung-Moon; Chu, Woo-Sung; Kim, Sang-Guk; Oh, Min-Cheol

2016-04-04

Optical current sensors based on polarization-rotated reflection interferometry are demonstrated using polymeric integrated optics and various functional optical waveguide devices. Interferometric sensors normally require bias feedback control for maintaining the operating point, which increases the cost. In order to resolve this constraint of feedback control, a multimode interference (MMI) waveguide device is integrated onto the current-sensor optical chip in this work. From the multiple outputs of the MMI, a 90° phase-shifted transfer function is obtained. Using passive quadrature demodulation, we demonstrate that the sensor could maintain the output signal regardless of the drift in the operating bias-point.

Evidence of Effectiveness of Health Care Professionals Using Handheld Computers: A Scoping Review of Systematic Reviews

PubMed Central

2013-01-01

Background Handheld computers and mobile devices provide instant access to vast amounts and types of useful information for health care professionals. Their reduced size and increased processing speed has led to rapid adoption in health care. Thus, it is important to identify whether handheld computers are actually effective in clinical practice. Objective A scoping review of systematic reviews was designed to provide a quick overview of the documented evidence of effectiveness for health care professionals using handheld computers in their clinical work. Methods A detailed search, sensitive for systematic reviews was applied for Cochrane, Medline, EMBASE, PsycINFO, Allied and Complementary Medicine Database (AMED), Global Health, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. All outcomes that demonstrated effectiveness in clinical practice were included. Classroom learning and patient use of handheld computers were excluded. Quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) tool. A previously published conceptual framework was used as the basis for dual data extraction. Reported outcomes were summarized according to the primary function of the handheld computer. Results Five systematic reviews met the inclusion and quality criteria. Together, they reviewed 138 unique primary studies. Most reviewed descriptive intervention studies, where physicians, pharmacists, or medical students used personal digital assistants. Effectiveness was demonstrated across four distinct functions of handheld computers: patient documentation, patient care, information seeking, and professional work patterns. Within each of these functions, a range of positive outcomes were reported using both objective and self-report measures. The use of handheld computers improved patient documentation through more complete recording, fewer documentation errors, and increased efficiency. Handheld computers provided easy access to

Evidence of effectiveness of health care professionals using handheld computers: a scoping review of systematic reviews.

PubMed

Mickan, Sharon; Tilson, Julie K; Atherton, Helen; Roberts, Nia Wyn; Heneghan, Carl

2013-10-28

Handheld computers and mobile devices provide instant access to vast amounts and types of useful information for health care professionals. Their reduced size and increased processing speed has led to rapid adoption in health care. Thus, it is important to identify whether handheld computers are actually effective in clinical practice. A scoping review of systematic reviews was designed to provide a quick overview of the documented evidence of effectiveness for health care professionals using handheld computers in their clinical work. A detailed search, sensitive for systematic reviews was applied for Cochrane, Medline, EMBASE, PsycINFO, Allied and Complementary Medicine Database (AMED), Global Health, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. All outcomes that demonstrated effectiveness in clinical practice were included. Classroom learning and patient use of handheld computers were excluded. Quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) tool. A previously published conceptual framework was used as the basis for dual data extraction. Reported outcomes were summarized according to the primary function of the handheld computer. Five systematic reviews met the inclusion and quality criteria. Together, they reviewed 138 unique primary studies. Most reviewed descriptive intervention studies, where physicians, pharmacists, or medical students used personal digital assistants. Effectiveness was demonstrated across four distinct functions of handheld computers: patient documentation, patient care, information seeking, and professional work patterns. Within each of these functions, a range of positive outcomes were reported using both objective and self-report measures. The use of handheld computers improved patient documentation through more complete recording, fewer documentation errors, and increased efficiency. Handheld computers provided easy access to clinical decision support systems and

Design, fabrication and analysis of integrated optical waveguide devices

NASA Astrophysics Data System (ADS)

Sikorski, Yuri

Throughout the present dissertation, the main effort has been to develop the set of design rules for optical integrated circuits (OIC). At the present time, when planar optical integrated circuits seem to be the leading technology, and industry is heading towards much higher levels of integration, such design rules become necessary. It is known that analysis of light propagation in rectangular waveguides can not be carried out exactly. Various approximations become necessary, and their validity is discussed in this text. Various methods are used in the text for calculating the same problems, and results are compared. A few new concepts have been suggested to avoid approximations used elsewhere. The second part of this dissertation is directed to the development of a new technique for the fabrication of optical integrated circuits inside optical glass. This technique is based on the use of ultrafast laser pulses to alter the properties of glasses. Using this method we demonstrated the possibility of changing the refractive index of various passive and active optical glasses as well as ablating the material on the surface in a controlled fashion. A number of optical waveguide devices (e.g. waveguides, directional couplers, diffraction gratings, fiber Bragg gratings, V-grooves in dual-clad optical fibers, optical waveguide amplifiers) were fabricated and tested. Testing included measurements of loss/throughput, near-field mode profiles, efficiency and thermal stability. All of the experimental setup and test results are reported in the dissertation. We also demonstrated the possibility of using this technique to fabricate future bio-optical devices that will incorporate an OIC and a microfluidic circuit on a single substrate. Our results are expected to serve as a guide for the design and fabrication of a new generation of integrated optical and bio-optical devices.

Abdominal aortic aneurysm screening program using hand-held ultrasound in primary healthcare

PubMed Central

Kostov, Belchin; Navarro González, Marta; Cararach Salami, Daniel; Pérez Jiménez, Alfonso; Gilabert Solé, Rosa; Bru Saumell, Concepció; Donoso Bach, Lluís; Villalta Martí, Mireia; González-de Paz, Luis; Ruiz Riera, Rafael; Riambau Alonso, Vicenç; Acar-Denizli, Nihan; Farré Almacellas, Marta; Ramos-Casals, Manuel; Benavent Àreu, Jaume

2017-01-01

We determined the feasibility of abdominal aortic aneurysm (AAA) screening program led by family physicians in public primary healthcare setting using hand-held ultrasound device. The potential study population was 11,214 men aged ≥ 60 years attended by three urban, public primary healthcare centers. Participants were recruited by randomly-selected telephone calls. Ultrasound examinations were performed by four trained family physicians with a hand-held ultrasound device (Vscan®). AAA observed were verified by confirmatory imaging using standard ultrasound or computed tomography. Cardiovascular risk factors were determined. The prevalence of AAA was computed as the sum of previously-known aneurysms, aneurysms detected by the screening program and model-based estimated undiagnosed aneurysms. We screened 1,010 men, with mean age of 71.3 (SD 6.9) years; 995 (98.5%) men had normal aortas and 15 (1.5%) had AAA on Vscan®. Eleven out of 14 AAA-cases (78.6%) had AAA on confirmatory imaging (one patient died). The total prevalence of AAA was 2.49% (95%CI 2.20 to 2.78). The median aortic diameter at diagnosis was 3.5 cm in screened patients and 4.7 cm (p<0.001) in patients in whom AAA was diagnosed incidentally. Multivariate logistic regression analysis identified coronary heart disease (OR = 4.6, 95%CI 1.3 to 15.9) as the independent factor with the highest odds ratio. A screening program led by trained family physicians using hand-held ultrasound was a feasible, safe and reliable tool for the early detection of AAA. PMID:28453577

Towards multimodal detection of melanoma thickness based on optical coherence tomography and optoacoustics

NASA Astrophysics Data System (ADS)

Rahlves, M.; Varkentin, A.; Stritzel, J.; Blumenröther, E.; Mazurenka, M.; Wollweber, M.; Roth, B.

2016-03-01

Melanoma skin cancer has one of the highest mortality rates of all types of cancer if not detected at an early stage. The survival rate is highly dependent on its penetration depth, which is commonly determined by histopathology. In this work, we aim at combining optical coherence tomography and optoacoustic as a non-invasive all-optical method to measure the penetration depth of melanoma. We present our recent achievements to setup a handheld multimodal device and also results from first in vivo measurements on healthy and cancerous skin tissue, which are compared to measurements obtained by ultrasound and histopathology.

Process overview of the high-visibility enforcement programs targeting handheld device users in California and Delaware.

DOT National Transportation Integrated Search

2015-01-01

The National Highway Traffic Safety Administration, the California Office of Traffic Safety, and the Delaware Highway Safety Office demonstrated State high-visibility enforcement (HVE) programs to reduce handheld phone use while driving. HVE was cond...

Application of X-Y Separable 2-D Array Beamforming for Increased Frame Rate and Energy Efficiency in Handheld Devices

PubMed Central

Owen, Kevin; Fuller, Michael I.; Hossack, John A.

2015-01-01

Two-dimensional arrays present significant beamforming computational challenges because of their high channel count and data rate. These challenges are even more stringent when incorporating a 2-D transducer array into a battery-powered hand-held device, placing significant demands on power efficiency. Previous work in sonar and ultrasound indicates that 2-D array beamforming can be decomposed into two separable line-array beamforming operations. This has been used in conjunction with frequency-domain phase-based focusing to achieve fast volume imaging. In this paper, we analyze the imaging and computational performance of approximate near-field separable beamforming for high-quality delay-and-sum (DAS) beamforming and for a low-cost, phaserotation-only beamforming method known as direct-sampled in-phase quadrature (DSIQ) beamforming. We show that when high-quality time-delay interpolation is used, separable DAS focusing introduces no noticeable imaging degradation under practical conditions. Similar results for DSIQ focusing are observed. In addition, a slight modification to the DSIQ focusing method greatly increases imaging contrast, making it comparable to that of DAS, despite having a wider main lobe and higher side lobes resulting from the limitations of phase-only time-delay interpolation. Compared with non-separable 2-D imaging, up to a 20-fold increase in frame rate is possible with the separable method. When implemented on a smart-phone-oriented processor to focus data from a 60 × 60 channel array using a 40 × 40 aperture, the frame rate per C-mode volume slice increases from 16 to 255 Hz for DAS, and from 11 to 193 Hz for DSIQ. Energy usage per frame is similarly reduced from 75 to 4.8 mJ/ frame for DAS, and from 107 to 6.3 mJ/frame for DSIQ. We also show that the separable method outperforms 2-D FFT-based focusing by a factor of 1.64 at these data sizes. This data indicates that with the optimal design choices, separable 2-D beamforming can

Noise tolerance in wavelength-selective switching of optical differential quadrature-phase-shift-keying pulse train by collinear acousto-optic devices.

PubMed

Goto, Nobuo; Miyazaki, Yasumitsu

2014-06-01

Optical switching of high-bit-rate quadrature-phase-shift-keying (QPSK) pulse trains using collinear acousto-optic (AO) devices is theoretically discussed. Since the collinear AO devices have wavelength selectivity, the switched optical pulse trains suffer from distortion when the bandwidth of the pulse train is comparable to the pass bandwidth of the AO device. As the AO device, a sidelobe-suppressed device with a tapered surface-acoustic-wave (SAW) waveguide and a Butterworth-type filter device with a lossy SAW directional coupler are considered. Phase distortion of optical pulse trains at 40 to 100  Gsymbols/s in QPSK format is numerically analyzed. Bit-error-rate performance with additive Gaussian noise is also evaluated by the Monte Carlo method.

Thermo-optic devices on polymer platform

NASA Astrophysics Data System (ADS)

Zhang, Ziyang; Keil, Norbert

2016-03-01

Optical polymers possess in general relatively high thermo-optic coefficients and at the same time low thermal conductivity, both of which make them attractive material candidates for realizing highly efficient thermally tunable devices. Over the years, various thermo-optic components have been demonstrated on polymer platform, covering (1) tunable reflectors and filters as part of a laser cavity, (2) variable optical attenuators (VOAs) as light amplitude regulators in e.g. a coherent receiver, and (3) thermo-optic switches (TOSs) allowing multi-flow control in the photonic integrated circuits (PICs). This work attempts to review the recent progress on the above mentioned three component branches, including linearly and differentially tunable filters, VOAs based on 1×1 multimode interference structure (MMI) and Mach-Zehnder interferometer (MZI), and 1×2 TOS based on waveguide Y-branch, driven by a pair of sidelong placed heater electrodes. These thermo-optic components can well be integrated into larger PICs: the dual-polarization switchable tunable laser and the colorless optical 90° hybrid are presented in the end as examples.

Hand-Held Sunphotometers for High School Student Construction and Measuring Aerosol Optical Thickness

NASA Technical Reports Server (NTRS)

Almonor, Linda; Baldwin, C.; Craig, R.; Johnson, L. P.

2000-01-01

Science education is taking the teaching of science from a traditional (lecture) approach to a multidimensional sense-making approach which allows teachers to support students by providing exploratory experiences. Using projects is one way of providing students with opportunities to observe and participate in sense-making activity. We created a learning environment that fostered inquiry-based learning. Students were engaged in a variety of Inquiry activities that enabled them to work in cooperative planning teams where respect for each other was encouraged and their ability to grasp, transform and transfer information was enhanced. Summer, 1998: An air pollution workshop was conducted for high school students in the Medgar Evers College/Middle College High School Liberty Partnership Summer Program. Students learned the basics of meteorology: structure and composition of the atmosphere and the processes that cause weather. The highlight of this workshop was the building of hand-held sunphotometers, which measure the intensity of the sunlight striking the Earth. Summer, 1999: high school students conducted a research project which measured the mass and size of ambient particulates and enhanced our ability to observe through land based measurements changes in the optical depth of ambient aerosols over Brooklyn. Students used hand held Sunphotometers to collect data over a two week period and entered it into the NASA GISS database by way of the internet.

Envisioning the Handheld-Centric Classroom

ERIC Educational Resources Information Center

Norris, Cathleen; Soloway, Elliot

2004-01-01

While appropriate as an initial focus, it is time that the educational community move beyond an emphasis on 1:1 computing (each child having his/her own personal computer) to a vision of a handheld-centric classroom, where each child not only has his/her own personal, handheld computer, but also has access to networked PCs, probeware, digital…

Rapid Diagnosis of an Ulnar Fracture with Portable Hand-Held Ultrasound

NASA Technical Reports Server (NTRS)

Kirkpatrick, Andrew W.; Brown, Ross; Diebel, Lawrence N.; Nicolaou, Savvas; Marshburn, Tom; Dulchavsky, Scott A.

2002-01-01

Orthopedic fractures are a common injury in operational activities, injuries that often occur in isolated or hostile environments. Clinical ultrasound devices have become more user friendly and lighter allowing them to be easily transported with forward medical teams. The bone-soft tissue interface has a very large acoustic impedance, with a high reflectance that can be used to visualize breaks in contour including fractures. Herein reported is a case of an ulnar fracture that was quickly visualized in the early phase of a multi-system trauma resuscitation with a hand-held ultrasound device. The implications for operational medicine are discussed.

Personal Devices in Public Settings: Lessons Learned from an iPod Touch/iPad Project

ERIC Educational Resources Information Center

Crichton, Susan; Pegler, Karen; White, Duncan

2012-01-01

Our paper reports findings from a two-phase deployment of iPod Touch and iPad devices in a large, urban Canadian school board. The purpose of the study was to gain an understanding of the infrastructure required to support handheld devices in classrooms; the opportunities and challenges teachers face as they begin to use handheld devices for…

Distance Estimation Using Handheld Devices

DTIC Science & Technology

2013-06-01

each and all centered in the pin that marks the location of the device. ................................47 Figure 21. Form interface where the UFO ...SIFT Scale-invariant feature transform SURF Speed up Robust Features SAD Sum of Absolute Distance UFOs Untrained Forward Observers WHATWG Web...Forward Observers ( UFOs ) to make a successful call for fire. This chapter presents the solution from different aspects and is organized as follows

DataPlus™ - a revolutionary applications generator for DOS hand-held computers

Treesearch

David Dean; Linda Dean

2000-01-01

DataPlus allows the user to easily design data collection templates for DOS-based hand-held computers that mimic clipboard data sheets. The user designs and tests the application on the desktop PC and then transfers it to a DOS field computer. Other features include: error checking, missing data checks, and sensor input from RS-232 devices such as bar code wands,...

Spatial transformation-enabled electromagnetic devices: from radio frequencies to optical wavelengths

PubMed Central

Jiang, Zhi Hao; Turpin, Jeremy P.; Morgan, Kennith; Lu, Bingqian; Werner, Douglas H.

2015-01-01

Transformation optics provides scientists and engineers with a new powerful design paradigm to manipulate the flow of electromagnetic waves in a user-defined manner and with unprecedented flexibility, by controlling the spatial distribution of the electromagnetic properties of a medium. Using this approach, over the past decade, various previously undiscovered physical wave phenomena have been revealed and novel electromagnetic devices have been demonstrated throughout the electromagnetic spectrum. In this paper, we present versatile theoretical and experimental investigations on designing transformation optics-enabled devices for shaping electromagnetic wave radiation and guidance, at both radio frequencies and optical wavelengths. Different from conventional coordinate transformations, more advanced and versatile coordinate transformations are exploited here to benefit diverse applications, thereby providing expanded design flexibility, enhanced device performance, as well as reduced implementation complexity. These design examples demonstrate the comprehensive capability of transformation optics in controlling electromagnetic waves, while the associated novel devices will open up new paths towards future integrated electromagnetic component synthesis and design, from microwave to optical spectral regimes. PMID:26217054

Spatial transformation-enabled electromagnetic devices: from radio frequencies to optical wavelengths.

PubMed

Jiang, Zhi Hao; Turpin, Jeremy P; Morgan, Kennith; Lu, Bingqian; Werner, Douglas H

2015-08-28

Transformation optics provides scientists and engineers with a new powerful design paradigm to manipulate the flow of electromagnetic waves in a user-defined manner and with unprecedented flexibility, by controlling the spatial distribution of the electromagnetic properties of a medium. Using this approach, over the past decade, various previously undiscovered physical wave phenomena have been revealed and novel electromagnetic devices have been demonstrated throughout the electromagnetic spectrum. In this paper, we present versatile theoretical and experimental investigations on designing transformation optics-enabled devices for shaping electromagnetic wave radiation and guidance, at both radio frequencies and optical wavelengths. Different from conventional coordinate transformations, more advanced and versatile coordinate transformations are exploited here to benefit diverse applications, thereby providing expanded design flexibility, enhanced device performance, as well as reduced implementation complexity. These design examples demonstrate the comprehensive capability of transformation optics in controlling electromagnetic waves, while the associated novel devices will open up new paths towards future integrated electromagnetic component synthesis and design, from microwave to optical spectral regimes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Optical forces near micro-fabricated devices

NASA Astrophysics Data System (ADS)

Mejia Prada, Camilo Andres

In this dissertation, I study optical forces near micro-fabricated devices for multi- particle manipulation. I consider particles of different sizes and compositions. In particular, I focus my study on both dielectric and gold particles as well as Giant Unilamellar Vesicles. First, I consider optical forces near a PhC and establish the feasibility of a technique which we term Light-Assisted Templated Self-assembly (LATS). In contrast to previous work on Fabry-Perot enhancement of trapping forces above a flat substrate, I exploit the guided resonance modes of a PhC to provide resonant enhancement of optical forces. Then, I explore optical forces near a Dual Beam Optical Trap (DBOT). I present a method to extract the bending modulus of the membrane from the area strain data. This method incorporates three-dimensional ray-tracing to calculate the applied stress in the DBOT within the ray optics approximation. I compare the optical force calculated using the ray optics approximation and Maxwell Stress Tensor method to ensure the approximation's accuracy. Next, we apply this method to 3 populations of GUVs to extract the bending modulus of membranes comprised of saturated and monounsaturated lipids in both gel and liquid phases.

Photonic sensor devices for explosive detection.

PubMed

Willer, Ulrike; Schade, Wolfgang

2009-09-01

For the sensitive online and in situ detection of gaseous species, optical methods are ideally suited. In contrast to chemical analysis, no sample preparation is necessary and therefore spectroscopic methods should be favorable both in respect of a fast signal recovery and economically because no disposal is needed. However, spectroscopic methods are currently not widely used for security applications. We review photonic sensor devices for the detection of explosives in the gas phase as well as the condensed phase and the underlying spectroscopic techniques with respect to their adaptability for security applications, where high sensitivity, high selectivity, and a low false-alarm rate are of importance. The measurements have to be performed under ambient conditions and often remote handling or even operation in standoff configuration is needed. For handheld and portable equipment, special attention is focused on the miniaturization and examples for already-available sensor devices are given.

Radiation effects in materials for optical interferometric devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koumvakalis, N.; Jani, M.G.; Halliburton, L.E.

The effects of ionizing radiation have been investigated in a series of materials commonly used in optical interferometric devices. Included in the study were three glass-ceramics (Zerodur, Cer-Vit 101, and Cer-Vit 142) and one Faraday-rotator glass (SF-57). Each glass-ceramic was irradiated at room temperature with 1.5-MeV electrons from a Van De Graaff accelerator. Similar irradiations were done on the Faraday-rotator glass at room temperature and 77 K. Optical absorption and electron spin resonance measurements provided a monitor of the radiation-induced point defects in all cases. The spectral characteristics and the production and thermal annealing behavior of these defects are described,more » and their possible effect on the performance of optical devices which incorporate these materials is considered.« less

3D wide field-of-view Gabor-domain optical coherence microscopy advancing real-time in-vivo imaging and metrology

NASA Astrophysics Data System (ADS)

Canavesi, Cristina; Cogliati, Andrea; Hayes, Adam; Tankam, Patrice; Santhanam, Anand; Rolland, Jannick P.

2017-02-01

Real-time volumetric high-definition wide-field-of-view in-vivo cellular imaging requires micron-scale resolution in 3D. Compactness of the handheld device and distortion-free images with cellular resolution are also critically required for onsite use in clinical applications. By integrating a custom liquid lens-based microscope and a dual-axis MEMS scanner in a compact handheld probe, Gabor-domain optical coherence microscopy (GD-OCM) breaks the lateral resolution limit of optical coherence tomography through depth, overcoming the tradeoff between numerical aperture and depth of focus, enabling advances in biotechnology. Furthermore, distortion-free imaging with no post-processing is achieved with a compact, lightweight handheld MEMS scanner that obtained a 12-fold reduction in volume and 17-fold reduction in weight over a previous dual-mirror galvanometer-based scanner. Approaching the holy grail of medical imaging - noninvasive real-time imaging with histologic resolution - GD-OCM demonstrates invariant resolution of 2 μm throughout a volume of 1 x 1 x 0.6 mm3, acquired and visualized in less than 2 minutes with parallel processing on graphics processing units. Results on the metrology of manufactured materials and imaging of human tissue with GD-OCM are presented.

Diffractive optical variable image devices generated by maskless interferometric lithography for optical security

NASA Astrophysics Data System (ADS)

Cabral, Alexandre; Rebordão, José M.

2011-05-01

In optical security (protection against forgery and counterfeit of products and documents) the problem is not exact reproduction but the production of something sufficiently similar to the original. Currently, Diffractive Optically Variable Image Devices (DOVID), that create dynamic chromatic effects which may be easily recognized but are difficult to reproduce, are often used to protect important products and documents. Well known examples of DOVID for security are 3D or 2D/3D holograms in identity documents and credit cards. Others are composed of shapes with different types of microstructures yielding by diffraction to chromatic dynamic effects. A maskless interferometric lithography technique to generate DOVIDs for optical security is presented and compared to traditional techniques. The approach can be considered as a self-masking focused holography on planes tilted with respect to the reference optical axes of the system, and is based on the Scheimpflug and Hinge rules. No physical masks are needed to ensure optimum exposure of the photosensitive film. The system built to demonstrate the technique relies on the digital mirrors device MOEMS technology from Texas Instruments' Digital Light Processing. The technique is linear on the number of specified colors and does not depend either on the area of the device or the number of pixels, factors that drive the complexity of dot-matrix based systems. The results confirmed the technique innovation and capabilities in the creation of diffractive optical elements for security against counterfeiting and forgery.

The association between handheld phone bans and the prevalence of handheld phone conversations among young drivers in the United States.

PubMed

Zhu, Motao; Rudisill, Toni M; Heeringa, Steven; Swedler, David; Redelmeier, Donald A

2016-12-01

Fourteen US states and the District of Columbia have banned handheld phone use for all drivers. We examined whether such legislation was associated with reduced handheld phone conversations among drivers aged younger than 25 years. Data from the 2008 to 2013 National Occupant Protection Use Survey were merged with states' legislation. The outcome was roadside-observed handheld phone conversation at stop signs or lights. Logistic regression was used. A total of 32,784 young drivers were observed. Relative to drivers who were observed in states without a universal handheld phone ban, the adjusted odds ratio of phone conversation was 0.42 (95% confidence interval, 0.33-0.53) for drivers who were observed in states with bans. The relative reduction in phone conversation was 46% (23%, 61%) for laws that were effective less than 1 year, 55% (32%, 70%) for 1-2 years, 63% (51%, 72%) for 2 years or more, relative to no laws. Universal handheld phone bans may be effective at reducing handheld phone use among young drivers. Copyright © 2016 Elsevier Inc. All rights reserved.

Dynamic Optical Grating Device and Associated Method for Modulating Light

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Choi, Sang H. (Inventor); King, Glen C. (Inventor); Chu, Sang-Hyon (Inventor)

2012-01-01

A dynamic optical grating device and associated method for modulating light is provided that is capable of controlling the spectral properties and propagation of light without moving mechanical components by the use of a dynamic electric and/or magnetic field. By changing the electric field and/or magnetic field, the index of refraction, the extinction coefficient, the transmittivity, and the reflectivity fo the optical grating device may be controlled in order to control the spectral properties of the light reflected or transmitted by the device.

Thermo-optically tunable thin film devices

NASA Astrophysics Data System (ADS)

Domash, Lawrence H.

2003-10-01

We report advances in tunable thin film technology and demonstration of multi-cavity tunable filters. Thin film interference coatings are the most widely used optical technology for telecom filtering, but until recently no tunable versions have been known except for mechanically rotated filters. We describe a new approach to broadly tunable components based on the properties of semiconductor thin films with large thermo-optic coefficients. The technology is based on amorphous silicon deposited by plasma-enhanced chemical vapor deposition (PECVD), a process adapted for telecom applications from its origins in the flat-panel display and solar cell industries. Unlike MEMS devices, tunable thin films can be constructed in sophisticated multi-cavity, multi-layer optical designs.

30 CFR 57.7053 - Moving hand-held drills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving hand-held drills. 57.7053 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before hand-held...

30 CFR 57.7053 - Moving hand-held drills.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Moving hand-held drills. 57.7053 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before hand-held...

30 CFR 57.7053 - Moving hand-held drills.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Moving hand-held drills. 57.7053 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before hand-held...

30 CFR 57.7053 - Moving hand-held drills.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Moving hand-held drills. 57.7053 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before hand-held...

30 CFR 57.7053 - Moving hand-held drills.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Moving hand-held drills. 57.7053 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before hand-held...

30 CFR 57.12033 - Hand-held electric tools.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not be...

30 CFR 57.12033 - Hand-held electric tools.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not be...

30 CFR 57.12033 - Hand-held electric tools.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not be...

30 CFR 57.12033 - Hand-held electric tools.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not be...

30 CFR 57.12033 - Hand-held electric tools.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not be...

Developing improved silica materials and devices for integrated optics applications

NASA Astrophysics Data System (ADS)

Maker, Ashley Julia

Due to their favorable optical and material properties, silica-based materials and devices have found many important applications throughout science and engineering, especially in sensing, communications, lasers, and integrated optics. Often, silica's properties ultimately limit the performance of these applications. To address this limitation, this thesis investigates the development of improved silica materials and optical devices, including silica films, coatings, waveguides, resonators, lasers, and sensors. Using sol-gel chemistry and microfabrication procedures, custom silica materials and devices are developed to benefit many applications. In this thesis, it is first demonstrated how the low optical loss of silica enables fabrication of low loss integrated waveguides and toroidal resonators with ultra-high quality factors. Then, by adding various rare earth and metal dopants to sol-gel silica, hybrid silica materials and devices are made with custom properties such as high refractive index and lasing capabilities. Finally, several applications are demonstrated, including the use of high refractive index coatings to control the behavior of light, development of Raman and ultra-low threshold rare earth microlasers, and a heterodyned microlaser sensor with significantly improved sensing performance. Future applications and directions of this research are also discussed.

Optical Sensing Device Containing Fiber Bragg Gratings

DTIC Science & Technology

2000-08-01

Fabry - Perot (SFP) filter-based interrogation (Kersey et al. Opt. Lett.. 18, 1370-2. 1993), tunable acousto-optic filter inteiTOgation (Geiger et al...a tunable Fabry - Perot filter, and a tunable acousto-optical filter. Alternatively, scanning filter 28 can be omitted in device 10 of the present...invention when broadband light source 20 is a tunable broadband light source. More preferably, scanning filter 28 is a tunable Fabry - Perot filter

30 CFR 56.7053 - Moving hand-held drills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving hand-held drills. 56.7053 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from one...

30 CFR 56.7053 - Moving hand-held drills.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Moving hand-held drills. 56.7053 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from one...

30 CFR 56.7053 - Moving hand-held drills.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Moving hand-held drills. 56.7053 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from one...

30 CFR 56.7053 - Moving hand-held drills.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Moving hand-held drills. 56.7053 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from one...

30 CFR 56.7053 - Moving hand-held drills.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Moving hand-held drills. 56.7053 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from one...

Development and testing of a scale to assess physician attitudes about handheld computers with decision support.

PubMed

Ray, Midge N; Houston, Thomas K; Yu, Feliciano B; Menachemi, Nir; Maisiak, Richard S; Allison, Jeroan J; Berner, Eta S

2006-01-01

The authors developed and evaluated a rating scale, the Attitudes toward Handheld Decision Support Software Scale (H-DSS), to assess physician attitudes about handheld decision support systems. The authors conducted a prospective assessment of psychometric characteristics of the H-DSS including reliability, validity, and responsiveness. Participants were 82 Internal Medicine residents. A higher score on each of the 14 five-point Likert scale items reflected a more positive attitude about handheld DSS. The H-DSS score is the mean across the fourteen items. Attitudes toward the use of the handheld DSS were assessed prior to and six months after receiving the handheld device. Cronbach's Alpha was used to assess internal consistency reliability. Pearson correlations were used to estimate and detect significant associations between scale scores and other measures (validity). Paired sample t-tests were used to test for changes in the mean attitude scale score (responsiveness) and for differences between groups. Internal consistency reliability for the scale was alpha = 0.73. In testing validity, moderate correlations were noted between the attitude scale scores and self-reported Personal Digital Assistant (PDA) usage in the hospital (correlation coefficient = 0.55) and clinic (0.48), p < 0.05 for both. The scale was responsive, in that it detected the expected increase in scores between the two administrations (3.99 (s.d. = 0.35) vs. 4.08, (s.d. = 0.34), p < 0.005). The authors' evaluation showed that the H-DSS scale was reliable, valid, and responsive. The scale can be used to guide future handheld DSS development and implementation.

Optical field dissipation in heterostructures for nanophotovoltaic devices

NASA Astrophysics Data System (ADS)

Villa-Angulo, Carlos; Sauceda-Carvajal, Daniel; Villa-Angulo, José R.; Villa-Angulo, Rafael

2016-10-01

In heterostructures for nanophotovoltaic (NPV) devices, a number of layers are concatenated in a multilayer configuration. In the analysis of a multilayer configuration, it is commonly assumed that the intensity of the optical field has an exponential decrease along the direction of propagation inside the structure. Effects such as reflections and interference are neglected. These neglected effects become especially important ones once the layer dimension reaches several nanometers. At this width regimen, quantum effects are present since layers are thin compared with the penetration depth and the wavelength of the incident light. Quantum effects influence photon absorption and affect the optical field dissipation that controls electron-hole pairs generation. Hence, dissipation of the optical field inside an NPV device is an important aspect to consider in studying and determining performance properties. We employed the one-dimensional optical transfer matrix theory and the quantum well theory to analyze the optical field dissipation in the active layer of heterostructures for NPV devices. Illumination of 100 mW·cm-2 air mass 1.5 global (AM 1.5G) standard was considered for the analysis. The study was extended to low-dimensional heterostructures of the binary compound CdS/CdSe/CdS, the ternary compound Ga0.9Al0.1As/GaAs/Ga0.9Al0.1As, and the quaternary compound In0.85Ga0.15As0.30P0.70/In0.7Ga0.3As0.6P0.4/In0.85Ga0.15As0.30P0.70.

Tunable Optical True-Time Delay Devices Would Exploit EIT

NASA Technical Reports Server (NTRS)

Kulikov, Igor; DiDomenico, Leo; Lee, Hwang

2004-01-01

Tunable optical true-time delay devices that would exploit electromagnetically induced transparency (EIT) have been proposed. Relative to prior true-time delay devices (for example, devices based on ferroelectric and ferromagnetic materials) and electronically controlled phase shifters, the proposed devices would offer much greater bandwidths. In a typical envisioned application, an optical pulse would be modulated with an ultra-wideband radio-frequency (RF) signal that would convey the information that one seeks to communicate, and it would be required to couple differently delayed replicas of the RF signal to the radiating elements of a phased-array antenna. One or more of the proposed devices would be used to impose the delays and/or generate the delayed replicas of the RF-modulated optical pulse. The beam radiated or received by the antenna would be steered by use of a microprocessor-based control system that would adjust operational parameters of the devices to tune the delays to the required values. EIT is a nonlinear quantum optical interference effect that enables the propagation of light through an initially opaque medium. A suitable medium must have, among other properties, three quantum states (see Figure 1): an excited state (state 3), an upper ground state (state 2), and a lower ground state (state 1). These three states must form a closed system that exhibits no decays to other states in the presence of either or both of two laser beams: (1) a probe beam having the wavelength corresponding to the photon energy equal to the energy difference between states 3 and 1; and (2) a coupling beam having the wavelength corresponding to the photon energy equal to the energy difference between states 3 and 2. The probe beam is the one that is pulsed and modulated with an RF signal.

Cellphone-based hand-held microplate reader for point-of-care ELISA testing (Conference Presentation)

NASA Astrophysics Data System (ADS)

Berg, Brandon; Cortazar, Bingen; Tseng, Derek; Ozkan, Haydar; Feng, Steve; Wei, Qingshan; Chan, Raymond Y.; Burbano, Jordi; Farooqui, Qamar; Lewinski, Michael; Di Carlo, Dino; Garner, Omai B.; Ozcan, Aydogan

2016-03-01

Enzyme-linked immunosorbent assay (ELISA) in a microplate format has been a gold standard first-line clinical test for diagnosis of various diseases including infectious diseases. However, this technology requires a relatively large and expensive multi-well scanning spectrophotometer to read and quantify the signal from each well, hindering its implementation in resource-limited-settings. Here, we demonstrate a cost-effective and handheld smartphone-based colorimetric microplate reader for rapid digitization and quantification of immunoserology-related ELISA tests in a conventional 96-well plate format at the point of care (POC). This device consists of a bundle of 96 optical fibers to collect the transmitted light from each well of the microplate and direct all the transmission signals from the wells onto the camera of the mobile-phone. Captured images are then transmitted to a remote server through a custom-designed app, and both quantitative and qualitative diagnostic results are returned back to the user within ~1 minute per 96-well plate by using a machine learning algorithm. We tested this mobile-phone based micro-plate reader in a clinical microbiology lab using FDA-approved mumps IgG, measles IgG, and herpes simplex virus IgG (HSV-1 and HSV-2) ELISA tests on 1138 remnant patient samples (roughly 50% training and 50% testing), and achieved an overall accuracy of ~99% or higher for each ELISA test. This handheld and cost-effective platform could be immediately useful for large-scale vaccination monitoring in low-infrastructure settings, and also for other high-throughput disease screening applications at POC.

Ionic Self-Assembled Monolayer (ISAM) Nonlinear Optical Thin Films and Devices

DTIC Science & Technology

1998-05-12

SUBTITLE " Ionic Self-Assembled Monolayer (ISAM) Nonlinear Optical Thin Films and Devices" 6. AUTHORS Michael B. Miller 5. FUNDING NUMBERS F49620-97...ii. Lü. Ionic Self-Assembled Monolayer (ISAM) Nonlinear Optical Thin Films and Devices Final Technical Report Performance Period: 15 August 1997...Investigator F&S. Inc.N ̂ 1. INTRODUCTION .’ 2 2. PROGRAM TASK REVIEW 2 3. BACKGROUND 4 3.1 NONLINEAR OPTICAL THIN FILMS 4 3.2 IONIC SELF

Demonstration of optically controlled data routing with the use of multiple-quantum-well bistable and electro-optical devices.

PubMed

Koppa, P; Chavel, P; Oudar, J L; Kuszelewicz, R; Schnell, J P; Pocholle, J P

1997-08-10

We present experimental results on a 1-to-64-channel free-space photonic switching demonstration system based on GaAs/GaAlAs multiple-quantum-well active device arrays. Two control schemes are demonstrated: data transparent optical self-routing usable in a packet-switching environment and direct optical control with potential signal amplification for circuit switching. The self-routing operation relies on the optical recognition of the binary destination address coded in each packet header. Address decoding is implemented with elementary optical bistable devices and modulator pixels as all-optical latches and electro-optical and gates, respectively. All 60 defect-free channels of the system could be operated one by one, but the simultaneous operation of only three channels could be achieved mainly because of the spatial nonhomogeneities of the devices. Direct-control operation is based on directly setting the bistable device reflectivity with a variable-control beam power. This working mode turned out to be much more tolerant of spatial noises: 37 channels of the system could be operated simultaneously. Further development of the system to a crossbar of N inputs and M outputs and system miniaturization are also considered.

Accuracy of Mobile Phone and Handheld Light Microscopy for the Diagnosis of Schistosomiasis and Intestinal Protozoa Infections in Côte d’Ivoire

PubMed Central

Coulibaly, Jean T.; Ouattara, Mamadou; D’Ambrosio, Michael V.; Fletcher, Daniel A.; Keiser, Jennifer; Utzinger, Jürg; N’Goran, Eliézer K.

2016-01-01

Background Handheld light microscopy using compact optics and mobile phones may improve the quality of health care in resource-constrained settings by enabling access to prompt and accurate diagnosis. Methodology Laboratory technicians were trained to operate two handheld diagnostic devices (Newton Nm1 microscope and a clip-on version of the mobile phone-based CellScope). The accuracy of these devices was compared to conventional light microscopy for the diagnosis of Schistosoma haematobium, S. mansoni, and intestinal protozoa infection in a community-based survey in rural Côte d’Ivoire. One slide of 10 ml filtered urine and a single Kato-Katz thick smear from 226 individuals were subjected to the Newton Nm1 microscope and CellScope for detection of Schistosoma eggs and compared to conventional microscopy. Additionally, 121 sodium acetate-acetic acid-formalin (SAF)-fixed stool samples were examined by the Newton Nm1 microscope and compared to conventional microscopy for the diagnosis of intestinal protozoa. Principal Findings The prevalence of S. haematobium, S. mansoni, Giardia intestinalis, and Entamoeba histolytica/E. dispar, as determined by conventional microscopy, was 39.8%, 5.3%, 20.7%, and 4.9%, respectively. The Newton Nm1 microscope had diagnostic sensitivities for S. mansoni and S. haematobium infection of 91.7% (95% confidence interval (CI) 59.8–99.6%) and 81.1% (95% CI 71.2–88.3%), respectively, and specificities of 99.5% (95% CI 97.0–100%) and 97.1% (95% CI 92.2–99.1%), respectively. The CellScope demonstrated sensitivities for S. mansoni and S. haematobium of 50.0% (95% CI 25.4–74.6%) and 35.6% (95% CI 25.9–46.4%), respectively, and specificities of 99.5% (95% CI 97.0–100%) and 100% (95% CI 86.7–100%), respectively. For G. intestinalis and E. histolytica/E. dispar, the Newton Nm1 microscope had sensitivity of 84.0% (95% CI 63.1–94.7%) and 83.3% (95% CI 36.5–99.1%), respectively, and 100% specificity. Conclusions

Accuracy of Mobile Phone and Handheld Light Microscopy for the Diagnosis of Schistosomiasis and Intestinal Protozoa Infections in Côte d'Ivoire.

PubMed

Coulibaly, Jean T; Ouattara, Mamadou; D'Ambrosio, Michael V; Fletcher, Daniel A; Keiser, Jennifer; Utzinger, Jürg; N'Goran, Eliézer K; Andrews, Jason R; Bogoch, Isaac I

2016-06-01

Handheld light microscopy using compact optics and mobile phones may improve the quality of health care in resource-constrained settings by enabling access to prompt and accurate diagnosis. Laboratory technicians were trained to operate two handheld diagnostic devices (Newton Nm1 microscope and a clip-on version of the mobile phone-based CellScope). The accuracy of these devices was compared to conventional light microscopy for the diagnosis of Schistosoma haematobium, S. mansoni, and intestinal protozoa infection in a community-based survey in rural Côte d'Ivoire. One slide of 10 ml filtered urine and a single Kato-Katz thick smear from 226 individuals were subjected to the Newton Nm1 microscope and CellScope for detection of Schistosoma eggs and compared to conventional microscopy. Additionally, 121 sodium acetate-acetic acid-formalin (SAF)-fixed stool samples were examined by the Newton Nm1 microscope and compared to conventional microscopy for the diagnosis of intestinal protozoa. The prevalence of S. haematobium, S. mansoni, Giardia intestinalis, and Entamoeba histolytica/E. dispar, as determined by conventional microscopy, was 39.8%, 5.3%, 20.7%, and 4.9%, respectively. The Newton Nm1 microscope had diagnostic sensitivities for S. mansoni and S. haematobium infection of 91.7% (95% confidence interval (CI) 59.8-99.6%) and 81.1% (95% CI 71.2-88.3%), respectively, and specificities of 99.5% (95% CI 97.0-100%) and 97.1% (95% CI 92.2-99.1%), respectively. The CellScope demonstrated sensitivities for S. mansoni and S. haematobium of 50.0% (95% CI 25.4-74.6%) and 35.6% (95% CI 25.9-46.4%), respectively, and specificities of 99.5% (95% CI 97.0-100%) and 100% (95% CI 86.7-100%), respectively. For G. intestinalis and E. histolytica/E. dispar, the Newton Nm1 microscope had sensitivity of 84.0% (95% CI 63.1-94.7%) and 83.3% (95% CI 36.5-99.1%), respectively, and 100% specificity. Handheld diagnostic devices can be employed in community-based surveys in resource

Promoting Physical Activity through Hand-Held Computer Technology

PubMed Central

King, Abby C.; Ahn, David K.; Oliveira, Brian M.; Atienza, Audie A.; Castro, Cynthia M.; Gardner, Christopher D.

2009-01-01

Background Efforts to achieve population-wide increases in walking and similar moderate-intensity physical activities potentially can be enhanced through relevant applications of state-of-the-art interactive communication technologies. Yet few systematic efforts to evaluate the efficacy of hand-held computers and similar devices for enhancing physical activity levels have occurred. The purpose of this first-generation study was to evaluate the efficacy of a hand-held computer (i.e., personal digital assistant [PDA]) for increasing moderate intensity or more vigorous (MOD+) physical activity levels over 8 weeks in mid-life and older adults relative to a standard information control arm. Design Randomized, controlled 8-week experiment. Data were collected in 2005 and analyzed in 2006-2007. Setting/Participants Community-based study of 37 healthy, initially underactive adults aged 50 years and older who were randomized and completed the 8-week study (intervention=19, control=18). Intervention Participants received an instructional session and a PDA programmed to monitor their physical activity levels twice per day and provide daily and weekly individualized feedback, goal setting, and support. Controls received standard, age-appropriate written physical activity educational materials. Main Outcome Measure Physical activity was assessed via the Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire at baseline and 8 weeks. Results Relative to controls, intervention participants reported significantly greater 8-week mean estimated caloric expenditure levels and minutes per week in MOD+ activity (p<0.04). Satisfaction with the PDA was reasonably high in this largely PDA-naive sample. Conclusions Results from this first-generation study indicate that hand-held computers may be effective tools for increasing initial physical activity levels among underactive adults. PMID:18201644

Fast and Scalable Fabrication of Microscopic Optical Surfaces and its Application for Optical Interconnect Devices

NASA Astrophysics Data System (ADS)

Summitt, Christopher Ryan

The use of optical interconnects is a promising solution to the increasing demand for high speed mass data transmission used in integrated circuits as well as device to device data transfer applications. For the purpose, low cost polymer waveguides are a popular choice for routing signal between devices due to their compatibility with printed circuit boards. In optical interconnect, coupling from an external light source to such waveguides is a critical step, thus a variety of couplers have been investigated such as grating based couplers [1,2], evanescent couplers [3], and embedded mirrors [4-6]. These couplers are inherently micro-optical components which require fast and scalable fabrication for mass production with optical quality surfaces/structures. Low NA laser direct writing has been used for fast fabrication of structures such as gratings and Fresnel lenses using a linear laser direct writing scheme, though the length scale of such structures are an order of magnitude larger than the spot size of the focused laser of the tool. Nonlinear writing techniques such as with 2-photon absorption offer increased write resolution which makes it possible to fabricate sub-wavelength structures as well as having a flexibility in feature shape. However it does not allow a high speed fabrication and in general are not scalable due to limitations of speed and area induced by the tool's high NA optics. To overcome such limitations primarily imposed by NA, we propose a new micro-optic fabrication process which extends the capabilities of 1D, low NA, and thus fast and scalable, laser direct writing to fabricate a structure having a length scale close to the tool's spot size, for example, a mirror based and 45 degree optical coupler with optical surface quality. The newly developed process allows a high speed fabrication with a write speed of 2600 mm²/min by incorporating a mask based lithography method providing a blank structure which is critical to creating a 45 degree

1-D ELECTRO-OPTIC BEAM STEERING DEVICE

PubMed Central

Wang, Wei-Chih; Tsui, Chi Leung

2011-01-01

In this paper, we present the design and fabrication of a 1D beam steering device based on planar electro-optic thermal-plastic prisms and a collimator lens array. With the elimination of moving parts, the proposed device is able to overcome the mechanical limitations of present scanning devices, such as fatigue and low operating frequency, while maintaining a small system footprint (~0.5mm×0.5mm). From experimental data, our prototype device is able to achieve a maximum deflection angle of 5.6° for a single stage prism design and 29.2° for a cascaded three prisms stage design. The lens array shows a 4µm collimated beam diameter. PMID:22199458

Predicting scattering scanning near-field optical microscopy of mass-produced plasmonic devices

NASA Astrophysics Data System (ADS)

Otto, Lauren M.; Burgos, Stanley P.; Staffaroni, Matteo; Ren, Shen; Süzer, Özgün; Stipe, Barry C.; Ashby, Paul D.; Hammack, Aeron T.

2018-05-01

Scattering scanning near-field optical microscopy enables optical imaging and characterization of plasmonic devices with nanometer-scale resolution well below the diffraction limit. This technique enables developers to probe and understand the waveguide-coupled plasmonic antenna in as-fabricated heat-assisted magnetic recording heads. In order to validate and predict results and to extract information from experimental measurements that is physically comparable to simulations, a model was developed to translate the simulated electric field into expected near-field measurements using physical parameters specific to scattering scanning near-field optical microscopy physics. The methods used in this paper prove that scattering scanning near-field optical microscopy can be used to determine critical sub-diffraction-limited dimensions of optical field confinement, which is a crucial metrology requirement for the future of nano-optics, semiconductor photonic devices, and biological sensing where the near-field character of light is fundamental to device operation.

Optical and Acoustic Device Applications of Ferroelastic Crystals

NASA Astrophysics Data System (ADS)

Meeks, Steven Wayne

This dissertation presents the discovery of a means of creating uniformly periodic domain gratings in a ferroelastic crystal of neodymium pentaphosphate (NPP). The uniform and non-uniform domain structures which can be created in NPP have the potential applications as tunable active gratings for lasers, tunable diffraction gratings, tunable Bragg reflection gratings, tunable acoustic filters, optical modulators, and optical domain wall memories. The interaction of optical and acoustic waves with ferroelastic domain walls in NPP is presented in detail. Acoustic amplitude reflection coefficients from a single domain wall in NPP are much larger than other ferroelastic-ferroelectrics such as gadolinium molybdate (GMO). Domain walls of NPP are used to make two demonstration acoustic devices: a tunable comb filter and a tunable delay line. The tuning process is accomplished by moving the position of the reflecting surface (the domain wall). A theory of the reflection of optical waves from NPP domain walls is discussed. The optical reflection is due to a change in the polarization of the wave, and not a change in the index, as the wave crosses the domain wall. Theoretical optical power reflection coefficients show good agreement with the experimentally measured values. The largest optical reflection coefficient of a single domain wall is at a critical angle and is 2.2% per domain wall. Techniques of injecting periodic and aperiodic domain walls into NPP are presented. The nucleation process of the uniformly periodic domain gratings in NPP is described in terms of a newly-discovered domain structure, namely the ferroelastic bubble. A ferroelastic bubble is the elastic analogue to the well-known magnetic bubble. The period of the uniformly periodic domain grating is tunable from 100 to 0.5 microns and the grating period may be tuned relatively rapidly. The Bragg efficiency of these tunable gratings is 77% for an uncoated crystal. Several demonstration devices which use

Glucose concentration in capillary blood of dairy cows obtained by a minimally invasive lancet technique and determined with three different hand-held devices.

PubMed

Mair, B; Drillich, M; Klein-Jöbstl, D; Kanz, P; Borchardt, S; Meyer, L; Schwendenwein, I; Iwersen, M

2016-02-24

Dairy cows have a massive demand for glucose at the onset of lactation. A poor adaption to this period leads to an excessive negative energy balance with an increased risk for ketosis and impaired animal health and production. Besides the measurement of ketones, analysing the glucose concentration in blood is reported as helpful instrument for diagnosis and differentiation of ketosis. Monitoring metabolic parameters requires multiple blood sampling. In other species, new blood sampling techniques have been introduced in which small amounts of blood are rapidly analysed using electronic hand-held devices. The objective of this study was to evaluate the suitability of capillary blood for blood glucose measurement in dairy cows using the hand-held devices FreeStyle Precision (FSP, Abbott), GlucoMen LX Plus (GLX, A. Menarini) and the WellionVet GLUCO CALEA, (WGC, MED TRUST). In total, 240 capillary blood samples were obtained from dry and fresh lactating Holstein-Friesian cows. Blood was collected from the skin of the exterior vulva by using a lancet. For method comparison, additional blood samples were taken from a coccygeal vessel and analyzed in a laboratory. Glucose concentrations measured by a standard laboratory method were defined as the criterion standard. The Pearson correlation coefficients between the glucose concentrations analyzed in capillary blood with the devices and the reference were 73% for the FSP, 81% for the GLX and 41% for the WGC. Bland-Altman plots showed biases of -18.8 mg/dL for the FSP, -11.2 mg/dL for the GLX and +20.82 mg/dL for the WGC. The optimized threshold determined by a Receiver Operating Characteristics analysis to detect hyperglycemia using the FSP was 43 mg/dL with a sensitivity (Se) and specificity (Sp) of 76 and 80%. Using the GLX and WGC optimized thresholds were 49 mg/dL (Se = 92%, Sp = 85%) and 95 mg/dL (Se = 39%, Sp = 92%). The results of this study demonstrate good performance characteristics for the GLX

Detection of radio-frequency modulated optical signals by two and three terminal microwave devices

NASA Technical Reports Server (NTRS)

Bhasin, K. B.; Simons, R. N.; Wojtczuk, S.

1987-01-01

An interdigitated photoconductor (two terminal device) on GaAlAs/GaAs heterostructure was fabricated and tested by an electro-optical sampling technique. Further, the photoresponse of GaAlAs/GaAs HEMT (three terminal device) was obtained by illuminating the device with an optical signal modulated up to 8 GHz. Gain-bandwidth product, response time, and noise properties of photoconductor and HEMT devices were obtained. Monolithic integration of these photodetectors with GaAs microwave devices for optically controlled phased array antenna applications is discussed.

Porous Materials with Ultralow Optical Constants for Integrated Optical Device Applications

NASA Astrophysics Data System (ADS)

Chen, Hsuen-Li; Hsieh, Chung-I; Cheng, Chao-Chia; Chang, Chia-Pin; Hsu, Wen-Hau; Wang, Way-Seen; Liu, Po-Tsun

2005-07-01

Ultralow dielectric constant (<2.0) porous materials have received much attention as next-generation dielectric materials. In this study, optical properties of porous-methyl-silsesquioxane(MSQ)-like films (porous polysilazane, PPSZ) were characterized for optical waveguide devices applications. Measured results indicate that the refractive index is decreased to approximately 1.320 as the hydration time exceeds 24 h. The measured refractive index is about 1.163 at a wavelength of 1550 nm. PPSZ films have low absorption in the 500 to 2000 nm wavelength regime. Because of their relatively low refractive index and low absorption over a large spectral regime, PPSZ films can be good cladding materials for use in optically integrated devices with many high-refractive-index materials such as silicon oxide, silicon nitride, silicon, and polymers. We demonstrate two structures, ridge waveguides and large-angle Y-branch power splitters, composed of PPSZ and SU8 films to illustrate the use of low dielectric constant (K) cladding materials. The simulation results indicate that the PPSZ films provide better confinement of light. Experimentally, a large-angle Y-branch power splitter with PPSZ cladding can be used to guide waves with the large branching angle of 33.58°.

Broadband achromatic optical metasurface devices.

PubMed

Wang, Shuming; Wu, Pin Chieh; Su, Vin-Cent; Lai, Yi-Chieh; Hung Chu, Cheng; Chen, Jia-Wern; Lu, Shen-Hung; Chen, Ji; Xu, Beibei; Kuan, Chieh-Hsiung; Li, Tao; Zhu, Shining; Tsai, Din Ping

2017-08-04

Among various flat optical devices, metasurfaces have presented their great ability in efficient manipulation of light fields and have been proposed for variety of devices with specific functionalities. However, due to the high phase dispersion of their building blocks, metasurfaces significantly suffer from large chromatic aberration. Here we propose a design principle to realize achromatic metasurface devices which successfully eliminate the chromatic aberration over a continuous wavelength region from 1200 to 1680 nm for circularly-polarized incidences in a reflection scheme. For this proof-of-concept, we demonstrate broadband achromatic metalenses (with the efficiency on the order of ∼12%) which are capable of focusing light with arbitrary wavelength at the same focal plane. A broadband achromatic gradient metasurface is also implemented, which is able to deflect wide-band light by the same angle. Through this approach, various flat achromatic devices that were previously impossible can be realized, which will allow innovation in full-color detection and imaging.Metasurfaces suffer from large chromatic aberration due to the high phase dispersion of their building blocks, limiting their applications. Here, Wang et al. design achromatic metasurface devices which eliminate the chromatic aberration over a continuous region from 1200 to 1680 nm in a reflection schleme.

Font size and viewing distance of handheld smart phones.

PubMed

Bababekova, Yuliya; Rosenfield, Mark; Hue, Jennifer E; Huang, Rae R

2011-07-01

The use of handheld smart phones for written communication is becoming ubiquitous in modern society. The relatively small screens found in these devices may necessitate close working distances and small text sizes, which can increase the demands placed on accommodation and vergence. Font size and viewing distance were measured while subjects used handheld electronic devices in two separate trials. In the first study (n=129), subjects were asked to show a typical text message on their own personal phone and to hold the device "as if they were about to read a text message." A second trial was conducted in a similar manner except subjects (n=100) were asked to view a specific web page from the internet. For text messages and internet viewing, the mean font size was 1.1 M (range, 0.7 to 2.1 M) and 0.8 M (range, 0.3 to 1.4 M), respectively. The mean working distance for text messages and internet viewing was 36.2 cm (range, 17.5 to 58.0 cm) and 32.2 cm (range, 19 to 60 cm), respectively. The mean font size for both conditions was comparable with newspaper print, although some subjects viewed text that was considerably smaller. However, the mean working distances were closer than the typical near working distance of 40 cm for adults when viewing hardcopy text. These close distances place increased demands on both accommodation and vergence, which could exacerbate symptoms. Practitioners need to consider the closer distances adopted while viewing material on smart phones when examining patients and prescribing refractive corrections for use at near, as well as when treating patients presenting with asthenopia associated with nearwork. Copyright © 2011 American Academy of Optometry

Tunable optical limiting optofluidic device filled with graphene oxide dispersion in ethanol

PubMed Central

Fang, Chaolong; Dai, Bo; Hong, Ruijin; Tao, Chunxian; Wang, Qi; Wang, Xu; Zhang, Dawei; Zhuang, Songlin

2015-01-01

An optofluidic device with tunable optical limiting property is proposed and demonstrated. The optofluidic device is designed for adjusting the concentration of graphene oxide (GO) in the ethanol solution and fabricated by photolithography technique. By controlling the flow rate ratio of the injection, the concentration of GO can be precisely adjusted so that the optical nonlinearity can be changed. The nonlinear optical properties and dynamic excitation relaxation of the GO/ethanol solution are investigated by using Z-scan and pump-probe measurements in the femtosecond regime within the 1.5 μm telecom band. The GO/ethanol solution presents ultrafast recovery time. Besides, the optical limiting property is in proportion to the concentration of the solution. Thus, the threshold power and the saturated power of the optical limiting property can be simply and efficiently manipulated by controlling the flow rate ratio of the injection. Furthermore, the amplitude regeneration is demonstrated by employing the proposed optofluidic device. The signal quality of intensity-impaired femtosecond pulse is significantly improved. The optofluidic device is compact and has long interaction length of optical field and nonlinear material. Heat can be dissipated in the solution and nonlinear material is isolated from other optical components, efficiently avoiding thermal damage and mechanical damage. PMID:26477662

Use of a hand-held meter for detecting subclinical ketosis in dairy cows.

PubMed

Voyvoda, Huseyin; Erdogan, Hasan

2010-12-01

The Optium Xceed is a new hand-held meter for determining blood β-hydroxybutyrate (BHBA) and glucose in human medicine. The objective of this study was to compare BHBA and glucose results obtained using the hand-held meter with those results made with a laboratory method and to evaluate its usefulness as a cowside test in the diagnosis of subclinical ketosis (SCK) in dairy cows. Seventy-eight blood samples from clinically healthy Holstein cows between 5 and 60 days post-calving were analysed. BHBA and glucose values were significantly higher with the hand-held meter versus laboratory methods. Correlation coefficients (r) for BHBA and glucose with the Optium Xceed versus laboratory methods were 0.97 and 0.63, respectively. Based on Bland-Altman plot and Passing-Bablok regression, agreement between two methods was good for BHBA but the agreement for glucose was only fair. When SCK was defined as plasma BHBA levels ≥ 1200 μmol/L, the sensitivity and specificity of the hand-held meter ketone testing in determining SCK were 85% and 94%, respectively. Raising the threshold of the laboratory method to ≥ 1400 μmol/L, the sensitivity and specificity incremented to 0.90 and 0.98, respectively. In conclusion, the blood ketone-monitoring device can be used as a rapid and reliable diagnostic test to detect SCK under field conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fehm, Thomas Felix; Razansky, Daniel, E-mail: dr@tum.de; Faculty of Medicine, Technische Universität München, Munich

2014-10-27

Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an opticalmore » absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.« less

The optical-mechanical design of DMD modulation imaging device

NASA Astrophysics Data System (ADS)

Li, Tianting; Xu, Xiping; Qiao, Yang; Li, Lei; Pan, Yue

2014-09-01

In order to avoid the phenomenon of some image information were lost, which is due to the jamming signals, such as incident laser, make the pixels dot on CCD saturated. In this article a device of optical-mechanical structure was designed, which utilized the DMD (Digital Micro mirror Device) to modulate the image. The DMD reflection imaging optical system adopts the telecentric light path. However, because the design is not only required to guarantee a 66° angle between the optical axis of the relay optics and the DMD, but also to ensure that the optical axis of the projection system keeps parallel with the perpendicular bisector of the micro-mirror which is in the "flat" state, so the TIR prism is introduced，and making the relay optics and the DMD satisfy the optical institution's requirements. In this paper, a mechanical structure of the imaging optical system was designed and at the meanwhile the lens assembly has been well connected and fixed and fine-tuned by detailed structural design, which included the tilt decentered lens, wedge flanges, prisms. By optimizing the design, the issues of mutual restraint between the inverting optical system and the projecting system were well resolved, and prevented the blocking of the two systems. In addition, the structure size of the whole DMD reflection imaging optical system was minimized; it reduced the energy loss and ensured the image quality.

Simple device for the direct visualization of oral-cavity tissue fluorescence

NASA Astrophysics Data System (ADS)

Lane, Pierre M.; Gilhuly, Terence; Whitehead, Peter D.; Zeng, Haishan; Poh, Catherine; Ng, Samson; Williams, Michelle; Zhang, Lewei; Rosin, Miriam; MacAulay, Calum E.

2006-03-01

Early identification of high-risk disease could greatly reduce both mortality and morbidity due to oral cancer. We describe a simple handheld device that facilitates the direct visualization of oral-cavity fluorescence for the detection of high-risk precancerous and early cancerous lesions. Blue excitation light (400 to 460 nm) is employed to excite green-red fluorescence from fluorophores in the oral tissues. Tissue fluorescence is viewed directly along an optical axis collinear with the axis of excitation to reduce inter- and intraoperator variability. This robust, field-of-view device enables the direct visualization of fluorescence in the context of surrounding normal tissue. Results from a pilot study of 44 patients are presented. Using histology as the gold standard, the device achieves a sensitivity of 98% and specificity of 100% when discriminating normal mucosa from severe dysplasia/carcinoma in situ (CIS) or invasive carcinoma. We envisage this device as a suitable adjunct for oral cancer screening, biopsy guidance, and margin delineation.

Precision optical device of freeform defects inspection

NASA Astrophysics Data System (ADS)

Meguellati, S.

2015-09-01

This method of optical scanning presented in this paper is used for precision measurement deformation in shape or absolute forms in comparison with a reference component form, of optical or mechanical components, on reduced surfaces area that are of the order of some mm2 and more. The principle of the method is to project the image of the source grating to palpate optically surface to be inspected, after reflection; the image of the source grating is printed by the object topography and is then projected onto the plane of reference grating for generate moiré fringe for defects detection. The optical device used allows a significant dimensional surface magnification of up to 1000 times the area inspected for micro-surfaces, which allows easy processing and reaches an exceptional nanometric imprecision of measurements. According to the measurement principle, the sensitivity for displacement measurement using moiré technique depends on the frequency grating, for increase the detection resolution. This measurement technique can be used advantageously to measure the deformations generated by the production process or constraints on functional parts and the influence of these variations on the function. The optical device and optical principle, on which it is based, can be used for automated inspection of industrially produced goods. It can also be used for dimensional control when, for example, to quantify the error as to whether a piece is good or rubbish. It then suffices to compare a figure of moiré fringes with another previously recorded from a piece considered standard; which saves time, money and accuracy. The technique has found various applications in diverse fields, from biomedical to industrial and scientific applications.

Handheld Computers: A Boon for Principals

ERIC Educational Resources Information Center

Brazell, Wayne

2005-01-01

As I reflect on my many years as an elementary school principal, I realize how much more effective I would have been if I had owned a wireless handheld computer. This relatively new technology can provide considerable assistance to today?s principals and recent advancements have increased its functions and capacity. Handheld computers are…

Device For Trapping Laser Pulses In An Optical Delay Line

DOEpatents

Yu, David U. L.; Bullock, Donald L.

1997-12-23

A device for maintaining a high-energy laser pulse within a recirculating optical delay line for a period time to optimize the interaction of the pulse with an electron beam pulse train comprising closely spaced electron micropulses. The delay line allows a single optical pulse to interact with many of the electron micropulses in a single electron beam macropulse in sequence and for the introduction of additional optical pulses to interact with the micropulses of additional electron beam macropulses. The device comprises a polarization-sensitive beam splitter for admitting an optical pulse to and ejecting it from the delay line according to its polarization state, a Pockels cell to control the polarization of the pulse within the delay line for the purpose of maintaining it within the delay line or ejecting it from the delay line, a pair of focusing mirrors positioned so that a collimated incoming optical pulse is focused by one of them to a focal point where the pulse interacts with the electron beam and then afterwards the pulse is recollimated by the second focusing mirror, and a timing device which synchronizes the introduction of the laser pulse into the optical delay line with the arrival of the electron macropulse at the delay line to ensure the interaction of the laser pulse with a prescribed number of electron micropulses in sequence. In a first embodiment of the invention, the principal optical elements are mounted with their axes collinear. In a second embodiment, all principal optical elements are mounted in the configuration of a ring.

Reconfigurable silicon thermo-optical device based on spectral tuning of ring resonators.

PubMed

Fegadolli, William S; Almeida, Vilson R; Oliveira, José Edimar Barbosa

2011-06-20

A novel tunable and reconfigurable thermo-optical device is theoretically proposed and analyzed in this paper. The device is designed to be entirely compatible with CMOS process and to work as a thermo-optical filter or modulator. Numerical results, made by means of analytical and Finite-Difference Time-Domain (FDTD) methods, show that a compact device enables a broad bandwidth operation, of up to 830 GHz, which allows the device to work under a large temperature variation, of up to 96 K.

Handheld Fluorescence Resonance Energy Transfer (FRET)-Aptamer Sensor for Bone Markers

NASA Technical Reports Server (NTRS)

Bruno, John G.

2015-01-01

Astronauts lose significant bone mass during lengthy space flights. NASA wishes to monitor this bone loss in order to develop nutritional and exercise countermeasures. Operational Technologies Corporation (OpTech) has developed a handheld device that quantifies bone loss in a spacecraft environment. The innovation works by adding fluorescent dyes and quenchers to aptamers to enable pushbutton, one-step bind-and-detect FRET assays that can be freeze-dried, rehydrated with body fluids, and used to quantify bone loss.

Hand-held radiometry: A set of notes developed for use at the Workshop of Hand-held radiometry

NASA Technical Reports Server (NTRS)

Jackson, R. D.; Pinter, P. J., Jr.; Reginato, R. J.; Idso, S. B. (Principal Investigator)

1980-01-01

A set of notes was developed to aid the beginner in hand-held radiometry. The electromagnetic spectrum is reviewed, and pertinent terms are defined. View areas of multiband radiometers are developed to show the areas of coincidence of adjacent bands. The amounts of plant cover seen by radiometers having different fields of view are described. Vegetation indices are derived and discussed. Response functions of several radiometers are shown and applied to spectrometer data taken over 12 wheat plots, to provide a comparison of instruments and bands within and among instruments. The calculation of solar time is reviewed and applied to the calculation of the local time of LANDSAT satellite overpasses for any particular location in the Northern Hemisphere. The use and misuse of hand-held infrared thermometers are discussed, and a procedure for photographic determination of plant cover is described. Some suggestions are offered concerning procedures to be followed when collecting hand-held spectral and thermal data. A list of references pertinent to hand-held radiometry is included.

Monitoring system of hydraulic lifting device based on the fiber optic sensors

NASA Astrophysics Data System (ADS)

Fajkus, Marcel; Nedoma, Jan; Novak, Martin; Martinek, Radek; Vanus, Jan; Mec, Pavel; Vasinek, Vladimir

2017-10-01

This article deals with the description of the monitoring system of hydraulic lifting device based on the fiber-optic sensors. For minimize the financial costs of the proposed monitoring system, the power evaluation of measured signal has been chosen. The solution is based on an evaluation of the signal obtained using the single point optic fiber sensors with overlapping reflective spectra. For encapsulation of the sensors was used polydimethylsiloxane (PDMS) polymer. To obtain a information of loading is uses the action of deformation of the lifting device on the pair single point optic fiber sensors mounted on the lifting device of the tested car. According to the proposed algorithm is determined information of pressure with an accuracy of +/- 5 %. Verification of the proposed system was realized on the various types of the tested car with different loading. The original contribution of the paper is to verify the new low-cost system for monitoring the hydraulic lifting device based on the fiber-optic sensors.

Active mode-locked lasers and other photonic devices using electro-optic whispering gallery mode resonators

NASA Technical Reports Server (NTRS)

Matsko, Andrey B. (Inventor); Ilchenko, Vladimir (Inventor); Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor)

2006-01-01

Techniques and devices using whispering gallery mode (WGM) optical resonators, where the optical materials of the WGM resonators exhibit an electro-optical effect to perform optical modulation. Examples of actively mode-locked lasers and other devices are described.

A novel optic bistable device with very low threshold intensity using photorefractive films

NASA Astrophysics Data System (ADS)

Wang, Sean X.; Sun, Yuankun; Trivedi, Sudhir B.; Li, Guifang

1994-08-01

Brimrose Corporation of America reports the successful completion of the SBIR Phase I research in low-threshold intensity optical bistable devices using photorefractive nonlinearity. A thin photorefractive film optical bistable device was proposed in the Phase I proposal. The feasibility of this device was theoretically investigated. The theoretical feasibility study formulates the materials requirements in such a kind of configuration for Phase II research. In addition, we have proposed and investigated another configuration of optical bistable devices that do not require advanced photorefractive materials, namely, the self-pumped phase conjugator. We have successfully demonstrated a low-threshold optical bistable operation in a KNSBN:CU crystal. To the best of our knowledge, the threshold of 650 mW/sq. cm is the lowest of its kind to be achieved so far.

Handheld computer use in U.S. family practice residency programs.

PubMed

Criswell, Dan F; Parchman, Michael L

2002-01-01

The purpose of the study was to evaluate the uses of handheld computers (also called personal digital assistants, or PDAs) in family practice residency programs in the United States. In November 2000, the authors mailed a questionnaire to the program directors of all American Academy of Family Physicians (AAFP) and American College of Osteopathic Family Practice (ACOFP) residency programs in the United States. Data and patterns of the use and non-use of handheld computers were identified. Approximately 50 percent (306 of 610) of the programs responded to the survey. Two thirds of the programs reported that handheld computers were used in their residencies, and an additional 14 percent had plans for implementation within 24 months. Both the Palm and the Windows CE operating systems were used, with the Palm operating system the most common. Military programs had the highest rate of use (8 of 10 programs, 80 percent), and osteopathic programs had the lowest (23 of 55 programs, 42 percent). Of programs that reported handheld computer use, 45 percent had required handheld computer applications that are used uniformly by all users. Funding for handheld computers and related applications was non-budgeted in 76percent of the programs in which handheld computers were used. In programs providing a budget for handheld computers, the average annual budget per user was 461.58 dollars. Interested faculty or residents, rather than computer information services personnel, performed upkeep and maintenance of handheld computers in 72 percent of the programs in which the computers are used. In addition to the installed calendar, memo pad, and address book, the most common clinical uses of handheld computers in the programs were as medication reference tools, electronic textbooks, and clinical computational or calculator-type programs. Handheld computers are widely used in family practice residency programs in the United States. Although handheld computers were designed as electronic

Handheld microwave bomb-detecting imaging system

NASA Astrophysics Data System (ADS)

Gorwara, Ashok; Molchanov, Pavlo

2017-05-01

Proposed novel imaging technique will provide all weather high-resolution imaging and recognition capability for RF/Microwave signals with good penetration through highly scattered media: fog, snow, dust, smoke, even foliage, camouflage, walls and ground. Image resolution in proposed imaging system is not limited by diffraction and will be determined by processor and sampling frequency. Proposed imaging system can simultaneously cover wide field of view, detect multiple targets and can be multi-frequency, multi-function. Directional antennas in imaging system can be close positioned and installed in cell phone size handheld device, on small aircraft or distributed around protected border or object. Non-scanning monopulse system allows dramatically decrease in transmitting power and at the same time provides increased imaging range by integrating 2-3 orders more signals than regular scanning imaging systems.

Handheld real-time volumetric imaging of the spine: technology development.

PubMed

Tiouririne, Mohamed; Nguyen, Sarah; Hossack, John A; Owen, Kevin; William Mauldin, F

2014-03-01

Technical difficulties, poor image quality and reliance on pattern identifications represent some of the drawbacks of two-dimensional ultrasound imaging of spinal bone anatomy. To overcome these limitations, this study sought to develop real-time volumetric imaging of the spine using a portable handheld device. The device measured 19.2 cm × 9.2 cm × 9.0 cm and imaged at 5 MHz centre frequency. 2D imaging under conventional ultrasound and volumetric (3D) imaging in real time was achieved and verified by inspection using a custom spine phantom. Further device performance was assessed and revealed a 75-min battery life and an average frame rate of 17.7 Hz in volumetric imaging mode. The results suggest that real-time volumetric imaging of the spine is a feasible technique for more intuitive visualization of the spine. These results may have important ramifications for a large array of neuraxial procedures.

An integrated optics microfluidic device for detecting single DNA molecules.

PubMed

Krogmeier, Jeffrey R; Schaefer, Ian; Seward, George; Yantz, Gregory R; Larson, Jonathan W

2007-12-01

A fluorescence-based integrated optics microfluidic device is presented, capable of detecting single DNA molecules in a high throughput and reproducible manner. The device integrates microfluidics for DNA stretching with two optical elements for single molecule detection (SMD): a plano-aspheric refractive lens for fluorescence excitation (illuminator) and a solid parabolic reflective mirror for fluorescence collection (collector). Although miniaturized in size, both optical components were produced and assembled onto the microfluidic device by readily manufacturable fabrication techniques. The optical resolution of the device is determined by the small and relatively low numerical aperture (NA) illuminator lens (0.10 effective NA, 4.0 mm diameter) that delivers excitation light to a diffraction limited 2.0 microm diameter spot at full width half maximum within the microfluidic channel. The collector (0.82 annular NA, 15 mm diameter) reflects the fluorescence over a large collection angle, representing 71% of a hemisphere, toward a single photon counting module in an infinity-corrected scheme. As a proof-of-principle experiment for this simple integrated device, individual intercalated lambda-phage DNA molecules (48.5 kb) were stretched in a mixed elongational-shear microflow, detected, and sized with a fluorescence signal to noise ratio of 9.9 +/-1.0. We have demonstrated that SMD does not require traditional high numerical aperture objective lenses and sub-micron positioning systems conventionally used in many applications. Rather, standard manufacturing processes can be combined in a novel way that promises greater accessibility and affordability for microfluidic-based single molecule applications.

Compact and high-efficiency device for Raman scattering measurement using optical fibers.

PubMed

Mitsui, Tadashi

2014-11-01

We describe the design and development of a high-efficiency optical measurement device for operation within the small bore of a high-power magnet at low temperature. For the high-efficiency measurement of light emitted from this small region, we designed a compact confocal optics with lens focusing and tilting systems, and used a piezodriven translation stage that allows micron-scale focus control of the sample position. We designed a measurement device that uses 10 m-long optical fibers in order to avoid the influence of mechanical vibration and magnetic field leakage of high-power magnets, and we also describe a technique for minimizing the fluorescence signal of optical fibers. The operation of the device was confirmed by Raman scattering measurements of monolayer graphene on quartz glass with a high signal-to-noise ratio.

High-speed low-power photonic transistor devices based on optically-controlled gain or absorption to affect optical interference.

PubMed

Huang, Yingyan; Ho, Seng-Tiong

2008-10-13

We show that a photonic transistor device can be realized via the manipulation of optical interference by optically controlled gain or absorption in novel ways, resulting in efficient transistor signal gain and switching action. Exemplary devices illustrate two complementary device types with high operating speed, microm size, microW switching power, and switching gain. They can act in tandem to provide a wide variety of operations including wavelength conversion, pulse regeneration, and logical operations. These devices could have a Transistor Figure-of-Merits >10(5) times higher than current chi((3)) approaches and are highly attractive.

Polymer electro-optic waveguide devices: Low-loss etchless fabrication techniques and passive-to-active integration

NASA Astrophysics Data System (ADS)

Geary, Kevin

The development of high-frequency polymer electro-optic modulators has seen steady and significant progress in recent years, yet applications of these promising materials to more complicated integrated optic structures and arrays of devices have been limited primarily due to high optical waveguide loss characteristics. This is unfortunate since a major advantage of polymers as photonic materials is their compatibility with photolithographic processing of large components. In this Dissertation, etchless waveguide writing techniques are presented in order to improve the overall optical insertion loss of electro-optic polymer waveguide devices. These techniques include poling-induced writing, stress-induced waveguide writing, and photobleaching. Using these waveguide writing mechanisms, we have demonstrated straight waveguides, phase modulators, Mach-Zehnder intensity modulators, variable optical attenuators, and multimode interference (MMI) power splitters, all with improved loss characteristics over their etched rib waveguide counterparts. Ultimately, the insertion loss of an integrated optic device is limited by the actual material loss of the core waveguide material. In this Dissertation, passive-to-active polymer waveguide transitions are proposed to circumvent this problem. These transitions are compact, in-plane, self-aligned, and require no tapering of any physical dimensions of the waveguides. By utilizing both the time-dependent and intensity-dependent photobleaching characteristics of electro-optic polymer materials, adiabatic refractive index tapers can be seamlessly coupled to in-plane butt couple transitions, resulting in losses as low as 0.1 dB per interface. By integrating passive polymer planar lightwave circuits with the high-speed phase shifting capability of electro-optic polymers, active wideband photonic devices of increased size and complexity can be realized. Optical fiber-to-device coupling can also result in significant contributions to the

Study of 3D printing method for GRIN micro-optics devices

NASA Astrophysics Data System (ADS)

Wang, P. J.; Yeh, J. A.; Hsu, W. Y.; Cheng, Y. C.; Lee, W.; Wu, N. H.; Wu, C. Y.

2016-03-01

Conventional optical elements are based on either refractive or reflective optics theory to fulfill the design specifications via optics performance data. In refractive optical lenses, the refractive index of materials and radius of curvature of element surfaces determine the optical power and wavefront aberrations so that optical performance can be further optimized iteratively. Although gradient index (GRIN) phenomenon in optical materials is well studied for more than a half century, the optics theory in lens design via GRIN materials is still yet to be comprehensively investigated before realistic GRIN lenses are manufactured. In this paper, 3D printing method for manufacture of micro-optics devices with special features has been studied based on methods reported in the literatures. Due to the additive nature of the method, GRIN lenses in micro-optics devices seem to be readily achievable if a design methodology is available. First, derivation of ray-tracing formulae is introduced for all possible structures in GRIN lenses. Optics simulation program is employed for characterization of GRIN lenses with performance data given by aberration coefficients in Zernike polynomial. Finally, a proposed structure of 3D printing machine is described with conceptual illustration.

3D printing of tissue-simulating phantoms for calibration of biomedical optical devices

NASA Astrophysics Data System (ADS)

Zhao, Zuhua; Zhou, Ximing; Shen, Shuwei; Liu, Guangli; Yuan, Li; Meng, Yuquan; Lv, Xiang; Shao, Pengfei; Dong, Erbao; Xu, Ronald X.

2016-10-01

Clinical utility of many biomedical optical devices is limited by the lack of effective and traceable calibration methods. Optical phantoms that simulate biological tissues used for optical device calibration have been explored. However, these phantoms can hardly simulate both structural and optical properties of multi-layered biological tissue. To address this limitation, we develop a 3D printing production line that integrates spin coating, light-cured 3D printing and Fused Deposition Modeling (FDM) for freeform fabrication of optical phantoms with mechanical and optical heterogeneities. With the gel wax Polydimethylsiloxane (PDMS), and colorless light-curable ink as matrix materials, titanium dioxide (TiO2) powder as the scattering ingredient, graphite powder and black carbon as the absorption ingredient, a multilayer phantom with high-precision is fabricated. The absorption and scattering coefficients of each layer are measured by a double integrating sphere system. The results demonstrate that the system has the potential to fabricate reliable tissue-simulating phantoms to calibrate optical imaging devices.

Eat-by-light fiber-optic and micro-optic devices for food quality and safety assessment

NASA Astrophysics Data System (ADS)

Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Grimaldi, M. F.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.

2007-06-01

A selection is presented of fiber-optic and micro-optic devices that have been designed and tested for guaranteeing the quality and safety of typical foods, such as extra virgin olive oil, beer, and milk. Scattered colorimetry is used to authenticate various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids, which are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma that is capable of distinguishing different ageing levels of extra virgin olive oil is also presented. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer for the rapid monitoring of the carcinogenic M1 aflatoxin in milk, is experimented.

Eat-by-light: fiber-optic and micro-optic devices for food safety and quality assessment

NASA Astrophysics Data System (ADS)

Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.

2007-07-01

A selection of fiber-optic and micro-optic devices is presented designed and tested for monitoring the quality and safety of typical foods, namely the extra virgin olive oil, the beer, and the milk. Scattered colorimetry is used for the authentication of various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids that are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma is presented. It is capable of distinguishing different ageing levels of extra virgin olive oil. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer is experimented for the rapid monitoring of the carcinogenic M1 aflatoxin in milk.

Selective Processing Techniques for Electronics and Opto-Electronic Applications: Quantum-Well Devices and Integrated Optic Circuits

DTIC Science & Technology

1993-02-10

new technology is to have sufficient control of processing to *- describable by an appropriate elecromagnetic model . build useful devices. For example...3. W aveguide Modulators .................................. 7 B. Integrated Optical Device and Circuit Modeling ... ................... .. 10 C...following categories: A. Integrated Optical Devices and Technology B. Integrated Optical Device and Circuit Modeling C. Cryogenic Etching for Low

Wireless live streaming video of laparoscopic surgery: a bandwidth analysis for handheld computers.

PubMed

Gandsas, Alex; McIntire, Katherine; George, Ivan M; Witzke, Wayne; Hoskins, James D; Park, Adrian

2002-01-01

Over the last six years, streaming media has emerged as a powerful tool for delivering multimedia content over networks. Concurrently, wireless technology has evolved, freeing users from desktop boundaries and wired infrastructures. At the University of Kentucky Medical Center, we have integrated these technologies to develop a system that can wirelessly transmit live surgery from the operating room to a handheld computer. This study establishes the feasibility of using our system to view surgeries and describes the effect of bandwidth on image quality. A live laparoscopic ventral hernia repair was transmitted to a single handheld computer using five encoding speeds at a constant frame rate, and the quality of the resulting streaming images was evaluated. No video images were rendered when video data were encoded at 28.8 kilobytes per second (Kbps), the slowest encoding bitrate studied. The highest quality images were rendered at encoding speeds greater than or equal to 150 Kbps. Of note, a 15 second transmission delay was experienced using all four encoding schemes that rendered video images. We believe that the wireless transmission of streaming video to handheld computers has tremendous potential to enhance surgical education. For medical students and residents, the ability to view live surgeries, lectures, courses and seminars on handheld computers means a larger number of learning opportunities. In addition, we envision that wireless enabled devices may be used to telemonitor surgical procedures. However, bandwidth availability and streaming delay are major issues that must be addressed before wireless telementoring becomes a reality.

Abdominoplasty and seroma: a prospective randomised study comparing scalpel and handheld electrocautery dissection.

PubMed

Marsh, Dan J; Fox, Andreas; Grobbelaar, Adriaan O; Chana, Jagdeep S

2015-02-01

Seroma formation remains a significant problem in abdominoplasty procedures--the cause of which remains to be elucidated. It has been suggested that one of the causative factors for seroma formation is the use of handheld electrocautery as opposed to scalpel for abdominal flap dissection. Prospective trial in 102 consecutive abdominoplasty patients randomised to have abdominal flap dissection with either handheld electrocautery device on 'coagulation setting' or sharp dissection with scalpel and monopolar electrocautery forceps for haemostasis. In all other aspects the surgical technique was identical between the two groups. All drains were removed at 48 h, irrespective of drain volume. Primary outcome measure is postoperative seroma formation on clinical examination, secondary outcome measures are drain volume, weight of tissue removed, effect of liposuction and patient BMI. Both study groups were similar in demographics with no significant difference in weight of tissue excised, BMI, drain output or post operative complictions. There was no significant difference in seroma formation rates between the handheld electrocautery group (17.2%) and the sharp dissection group (20.1%). Overall, the seroma rate was 18.6%. Liposuction to the flanks at the time of abdominoplasty was found to significantly increase the incidence of seroma, compared to patients having abdominoplasty alone. Use of handheld electrocautery rather than scalpel for tissue dissection does not lead to increased seroma formation in abdominoplasty patients. Concomitant liposuction at the time of abdominoplasty increases the risk of seroma formation compared to patients having abdominoplasty alone. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Wireless Handhelds to Support Clinical Nursing Practicum

ERIC Educational Resources Information Center

Wu, Cheng-Chih; Lai, Chin-Yuan

2009-01-01

This paper reports our implementation and evaluation of a wireless handheld learning environment used to support a clinical nursing practicum course. The learning environment was designed so that nursing students could use handhelds for recording information, organizing ideas, assessing patients, and also for interaction and collaboration with…

Handheld Diffusion Test Cells

NASA Technical Reports Server (NTRS)

2001-01-01

This photo shows the Handheld Diffusion Test Cell (HH-DTC) apparatus flown on the Space Shuttle. Similar cells (inside the plastic box) will be used in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

Handheld Diffusion Test Cells

NASA Technical Reports Server (NTRS)

2001-01-01

This photo shows an individual cell from the Handheld Diffusion Test Cell (HH-DTC) apparatus flown on the Space Shuttle. Similar cells will be used in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

Handheld Computer Use in U.S. Family Practice Residency Programs

PubMed Central

Criswell, Dan F.; Parchman, Michael L.

2002-01-01

Objective: The purpose of the study was to evaluate the uses of handheld computers (also called personal digital assistants, or PDAs) in family practice residency programs in the United States. Study Design: In November 2000, the authors mailed a questionnaire to the program directors of all American Academy of Family Physicians (AAFP) and American College of Osteopathic Family Practice (ACOFP) residency programs in the United States. Measurements: Data and patterns of the use and non-use of handheld computers were identified. Results: Approximately 50 percent (306 of 610) of the programs responded to the survey. Two thirds of the programs reported that handheld computers were used in their residencies, and an additional 14 percent had plans for implementation within 24 months. Both the Palm and the Windows CE operating systems were used, with the Palm operating system the most common. Military programs had the highest rate of use (8 of 10 programs, 80 percent), and osteopathic programs had the lowest (23 of 55 programs, 42 percent). Of programs that reported handheld computer use, 45 percent had required handheld computer applications that are used uniformly by all users. Funding for handheld computers and related applications was non-budgeted in 76percent of the programs in which handheld computers were used. In programs providing a budget for handheld computers, the average annual budget per user was $461.58. Interested faculty or residents, rather than computer information services personnel, performed upkeep and maintenance of handheld computers in 72 percent of the programs in which the computers are used. In addition to the installed calendar, memo pad, and address book, the most common clinical uses of handheld computers in the programs were as medication reference tools, electronic textbooks, and clinical computational or calculator-type programs. Conclusions: Handheld computers are widely used in family practice residency programs in the United States

Compact system with handheld microfabricated optoelectronic probe for needle-based tissue sensing applications

NASA Astrophysics Data System (ADS)

Lee, Seung Yup; Na, Kyounghwan; Pakela, Julia M.; Scheiman, James M.; Yoon, Euisik; Mycek, Mary-Ann

2017-02-01

We present the design, development, and bench-top verification of an innovative compact clinical system including a miniaturized handheld optoelectronic sensor. The integrated sensor was microfabricated with die-level light-emitting diodes and photodiodes and fits into a 19G hollow needle (internal diameter: 0.75 mm) for optical sensing applications in solid tissues. Bench-top studies on tissue-simulating phantoms have verified system performance relative to a fiberoptic based tissue spectroscopy system. With dramatically reduced system size and cost, the technology affords spatially configurable designs for optoelectronic light sources and detectors, thereby enabling customized sensing configurations that would be impossible to achieve with needle-based fiber-optic probes.

Design and simulation of multifunctional optical devices using metasurfaces

NASA Astrophysics Data System (ADS)

Alyammahi, Saleimah

momentum (OAM). New designs of ultrathin, planar metasurfaces may result in development of a new type of photonic devices with reduced loss and broad bandwidth. The advances in metasurface designs will lead to ultrathin devices with surprising functionalities and low cost. These novel designs may offer more possibilities for applications in quantum optic devices, pulse shaping, spatial light modulators, nano-scale sensing or imaging, and so on.

Vitreous Bands Identified by Handheld Spectral-Domain Optical Coherence Tomography Among Premature Infants.

PubMed

Zepeda, Emily M; Shariff, Ayesha; Gillette, Thomas B; Grant, Laura; Ding, Leona; Tarczy-Hornoch, Kristina; Cabrera, Michelle T

2018-05-17

Handheld spectral-domain optical coherence tomography (SD-OCT) can provide insights into the complex interactions occurring at the vitreoretinal interface in retinopathy of prematurity (ROP) to enhance our understanding of ROP pathology. To characterize vitreous bands in premature infants with use of handheld SD-OCT. Prospective cohort study conducted from July 7, 2015, to February 28, 2017, at 2 university-based neonatal intensive care units. Seventy-three premature infants who required routine ROP screening examination were recruited. Informed consent was obtained from all legal guardians. Trained graders who were masked to the clinical assessment analyzed each SD-OCT scan of the right eye for vitreoretinal findings. A third trained grader mediated disagreements. Associations between the presence of vitreous bands in premature infants with ROP diagnoses and the presence of other vitreoretinal SD-OCT findings were investigated. Of the 73 infants recruited, 6 infants' parents withdrew their children from the study, and 2 infants were too hemodynamically unstable for imaging, leaving a total of 65 participants. Of these, 32 (49%) were female, 36 (55%) were white, 10 (15%) were Hispanic, 3 (5%) were Native American, 4 (6%) were African American, 4 (7%) were Asian/Pacific Islander, and 8 (12%) were other. The mean (SD) gestational age was 28 (2.7) weeks, the mean (SD) birth weight was 997 g (286 g), and the mean (SD) postmenstrual age at imaging was 34 (3) weeks (mean [SD] total of 3 [2] imaging sessions). Comparing the 24 infants (37%) who had a right eye vitreous band at any time with the 41 (63%) who did not, no difference in mean birth weight, gestational age, postmenstrual age at imaging, sex, or race/ethnicity was identified. No associations with ROP stage (eg, in 6 [25%] infants with vitreous bands vs 4 [9.8%] in those without; P = .23), presence of plus disease (2 [8%] vs 2 [5%]; P = .84), or type 1 ROP (3 [12%] vs 3 [7%]; P = .66) were identified

Driver performance while text messaging using handheld and in-vehicle systems.

PubMed

Owens, Justin M; McLaughlin, Shane B; Sudweeks, Jeremy

2011-05-01

This study presents an evaluation of driver performance while text messaging via handheld mobile phones and an in-vehicle texting system. Participants sent and received text messages while driving with an experimenter on a closed-road course, using their personal mobile phones and the vehicle's system. The test vehicle was an instrumented 2010 Mercury Mariner equipped with an OEM in-vehicle system that supports text messaging and voice control of mobile devices via Bluetooth, which was modified to allow text message sending during driving. Twenty participants were tested, 11 younger (19-34) and 9 older (39-51). All participants were regular users of the in-vehicle system, although none had experience with the texting functions. Results indicated that handheld text message sending and receiving resulted in higher mental demand, more frequent and longer glances away from the roadway, and degraded steering measures compared to baseline. Using the in-vehicle system to send messages showed less performance degradation, but still had more task-related interior glance time and higher mental demand than baseline; using the system's text-to-speech functionality for incoming messages showed no differences from baseline. These findings suggest that using handheld phones to send and receive text messages may interfere with drivers' visual and steering behaviors; the in-vehicle system showed improvement, but performance was not at baseline levels during message sending. Copyright © 2010 Elsevier Ltd. All rights reserved.

Spectral domain, common path OCT in a handheld PIC based system

NASA Astrophysics Data System (ADS)

Leinse, Arne; Wevers, Lennart; Marchenko, Denys; Dekker, Ronald; Heideman, René G.; Ruis, Roosje M.; Faber, Dirk J.; van Leeuwen, Ton G.; Kim, Keun Bae; Kim, Kyungmin

2018-02-01

Optical Coherence Tomography (OCT) has made it into the clinic in the last decade with systems based on bulk optical components. The next disruptive step will be the introduction of handheld OCT systems. Photonic Integrated Circuit (PIC) technology is the key enabler for this further miniaturization. PIC technology allows signal processing on a stable platform and the implementation of a common path interferometer in that same platform creates a robust fully integrated OCT system with a flexible fiber probe. In this work the first PIC based handheld and integrated common path based spectral domain OCT system is described and demonstrated. The spectrometer in the system is based on an Arrayed Waveguide Grating (AWG) and fully integrated with the CCD and a fiber probe into a system operating at 850 nm. The AWG on the PIC creates a 512 channel spectrometer with a resolution of 0.22 nm enabling a high speed analysis of the full A-scan. The silicon nitride based proprietary waveguide technology (TriPleXTM) enables low loss complex photonic structures from the visible (405 nm) to IR (2350 nm) range, making it a unique candidate for OCT applications. Broadband AWG operation from visible to 1700 nm has been shown in the platform and Photonic Design Kits (PDK) are available enabling custom made designs in a system level design environment. This allows a low threshold entry for designing new (OCT) designs for a broad wavelength range.

An Integrated Quantum Dot Barcode Smartphone Optical Device for Wireless Multiplexed Diagnosis of Infected Patients

NASA Astrophysics Data System (ADS)

Ming, Kevin

Integrating mobile-cellular devices with multiplex molecular diagnostics can potentially provide the most powerful platform for tracking, managing and preventing the transmission of infectious diseases. With over 6.9 billion subscriptions globally, handheld mobile-cellular devices can be programmed to spatially map, temporally track, and transmit information on infections over wide geographical space and boundaries. Current cell phone diagnostic technologies have poor limit of detection, dynamic range, and cannot detect multiple pathogen targets simultaneously, limiting their utility to single infections with high load. Here we combined recent advances in quantum dot barcode technology for molecular detection with smartphones to engineer a simple and low-cost chip-based wireless multiplex diagnostic device. We validated our device using a variety of synthetic genomic targets for the respiratory virus and blood-borne pathogens, and demonstrated that it could detect clinical samples after simple amplification. More importantly, we confirmed that the device is capable of detecting patients infected with a single or multiple infectious pathogens (e.g., HIV and hepatitis B) in a single test. This device advances the capacity for global surveillance of infectious diseases and has the potential to accelerate knowledge exchange-transfer of emerging or exigent disease threats with healthcare and military organizations in real-time.

Pilot Project for Spaceborne Massive Optical Storage Devices

NASA Technical Reports Server (NTRS)

Chen, Y. J.

1996-01-01

A space bound storage device has many special requirements. In addition to large storage capacity, fas read/ write time, and high reliability, it also needs to have small volume, light weight, low power consumption, radiation hardening, ability to operate in extreme temperature ranges, etc. Holographic optical recording technology, which has been making major advancements in recent years, is an extremely promising candidate. The goal of this pilot project is to demonstrate a laboratory bench-top holographic optical recording storage system (HORSS) based on nonlinear polymer films 1 and/or other advanced photo-refractive materials. This system will be used as a research vehicle to study relevant optical properties of novel holographic optical materials, to explore massive optical storage technologies based on the photo-refractive effect and to evaluate the feasibility of developing a massive storage system, based on holographic optical recording technology, for a space bound experiment in the near future.

Do hand-held calorimeters provide reliable and accurate estimates of resting metabolic rate?

PubMed

Van Loan, Marta D

2007-12-01

This paper provides an overview of a new technique for indirect calorimetry and the assessment of resting metabolic rate. Information from the research literature includes findings on the reliability and validity of a new hand-held indirect calorimeter as well as use in clinical and field settings. Research findings to date are of mixed results. The MedGem instrument has provided more consistent results when compared to the Douglas bag method of measuring metabolic rate. The BodyGem instrument has been shown to be less accurate when compared to standard metabolic carts. Furthermore, when the Body Gem has been used with clinical patients or with under nourished individuals the results have not been acceptable. Overall, there is not a large enough body of evidence to definitively support the use of these hand-held devices for assessment of metabolic rate in a wide variety of clinical or research environments.

Limitations and Tolerances in Optical Devices

NASA Astrophysics Data System (ADS)

Jackman, Neil Allan

The performance of optical systems is limited by the imperfections of their components. Many of the devices in optical systems including optical fiber amplifiers, multimode transmission lines and multilayered media such as mirrors, windows and filters, are modeled by coupled line equations. This investigation includes: (i) a study of the limitations imposed on a wavelength multiplexed unidirectional ring by the non-uniformities of the gain spectra of Erbium-doped optical fiber amplifiers. We find numerical solutions for non-linear coupled power differential equations and use these solutions to compare the signal -to-noise ratios and signal levels at different nodes. (ii) An analytical study of the tolerances of imperfect multimode media which support forward traveling modes. The complex mode amplitudes are related by linear coupled differential equations. We use analytical methods to derive extended equations for the expected mode powers and give heuristic limits for their regions of validity. These results compare favorably to exact solutions found for a special case. (iii) A study of the tolerances of multilayered media in the presence of optical thickness imperfections. We use analytical methods including Kronecker producers, to calculate the reflection and transmission statistics of the media. Monte Carlo simulations compare well to our analytical method.

Mobile Learning Devices. Essentials for Principals

ERIC Educational Resources Information Center

Rogers, Kipp D.

2011-01-01

In "Mobile Learning Devices," the author helps educators confront and overcome their fears and doubts about using mobile learning devices (MLDs) such as cell phones, personal digital assistants, MP3 players, handheld games, digital audio players, and laptops in classrooms. School policies that ban such tools are outdated, the author suggests;…

Novel optical interconnect devices applying mask-transfer self-written method

NASA Astrophysics Data System (ADS)

Ishizawa, Nobuhiko; Matsuzawa, Yusuke; Tokiwa, Yu; Nakama, Kenichi; Mikami, Osamu

2012-01-01

The introduction of optical interconnect technology is expected to solve problems of conventional electric wiring. One of the promising technologies realizing optical interconnect is the self-written waveguide (SWW) technology with lightcurable resin. We have developed a new technology of the "Mask-Transfer Self-Written (MTSW)" method. This new method enables fabrication of arrayed M x N optical channels at one shot of UV-light. Using this technology, several new optical interconnect devices and connection technologies have been proposed and investigated. In this paper, first, we introduce MTSW method briefly. Next, we show plug-in alignment approach using optical waveguide plugs (OWP) and a micro-hole array (MHA) which are made of the light-curable resin. Easy and high efficiency plug-in alignment between fibers and an optoelectronic-printed wiring board (OE-PWB), between a fiber and a VCSEL, so on will be feasible. Then, we propose a new three-dimensional (3D) branch waveguide. By controlling the irradiating angle through the photomask aperture, it will be possible to fabricate 2-branch and 4-branch waveguides with a certain branch angle. The 3D branch waveguide will be very promising in the future optical interconnects and coupler devices of the multicore optical fiber.

Preclinical imaging of iridocorneal angle and fundus using a modified integrated flexible handheld probe

PubMed Central

Hong, Xun Jie Jeesmond; Shinoj, Vengalathunadakal K.; Murukeshan, Vadakke Matham; Baskaran, Mani; Aung, Tin

2017-01-01

Abstract. A flexible handheld imaging probe consisting of a 3  mm×3  mm charge-coupled device camera, light-emitting diode light sources, and near-infrared laser source is designed and developed. The imaging probe is designed with specifications to capture the iridocorneal angle images and posterior segment images. Light propagation from the anterior chamber of the eye to the exterior is considered analytically using Snell’s law. Imaging of the iridocorneal angle region and fundus is performed on ex vivo porcine samples and subsequently on small laboratory animals, such as the New Zealand white rabbit and nonhuman primate, in vivo. The integrated flexible handheld probe demonstrates high repeatability in iridocorneal angle and fundus documentation. The proposed concept and methodology are expected to find potential application in the diagnosis, prognosis, and management of glaucoma. PMID:28413809

[Devic disease: a rare cause of retrobulbar optic neuritis: a case report].

PubMed

Sempińska-Szewczyk, J; Weglewski, A; Juryńczyk, J; Cybulska, B

2000-01-01

A case of 58-year-old woman with recurrent retrobulbar optic neuritis (ron) and transverse myelitis is presented. The patient was admitted to the opthalmology unit because of acute right retrobulbar optic neuritis. In 1997 she complained of left retrobulbar optic neuritis. One year later transverse myelitis of thoracic spine with spastic paraparesis occurred. MRI examination showed T2 hyperintensive focus in the thoracic spine (Th8-Th9, probably demyelinisation). Nowadays MRI examination of the optic nerves and brain showed demyelinisation focus in the right optic nerve. There was no pathological changes in the brain. The diagnosis of Devic disease was established. Treatment with intravenous methyloprednisolon was administered with slight improvement. The pathology and clinical course of Devic disease are discussed.

Handheld directional reflectometer: an angular imaging device to measure BRDF and HDR in real time

NASA Astrophysics Data System (ADS)

Mattison, Phillip R.; Dombrowski, Mark S.; Lorenz, James M.; Davis, Keith J.; Mann, Harley C.; Johnson, Philip; Foos, Bryan

1998-10-01

Many applications require quantitative measurements of surface light scattering, including quality control on production lines, inspection of painted surfaces, inspection of field repairs, etc. Instruments for measuring surface scattering typically fall into two main categories, namely bidirectional reflectometers, which measure the angular distribution of scattering, and hemispherical directional reflectometers, which measure the total scattering into the hemisphere above the surface. Measurement of the bi-directional reflectance distribution function (BRDF) gives the greatest insight into how light is scattered from a surface. Measurements of BRDF, however, are typically very lengthy measurements taken by moving a source and detector to map the scattering. Since BRDF has four angular degrees of freedom, such measurements can require hours to days to complete. Instruments for measuring BRDF are also typically laboratory devices, although a field- portable bi-directional reflectometer does exist. Hemispherical directional reflectance (HDR) is a much easier measurement to make, although care must be taken to use the proper methodology when measuring at wavelengths beyond 10 micrometer, since integrating spheres (typically used to make such measurements) are very energy inefficient and lose their integrating properties at very long wavelengths. A few field- portable hemispherical directional reflectometers do exist, but typically measure HDR only at near-normal angles. Boeing Defense and Space Group and Surface Optics Corporation, under a contract from the Air Force Research Laboratory, have developed a new hand-held instrument capable of measuring both BRDF and HDR using a unique, patented angular imaging technique. A combination of an hemi-ellipsoidal mirror and an additional lens translate the angular scatter from a surface into a two-dimensional spatial distribution, which is recorded by an imaging array. This configuration fully maps the scattering from a half

Acceptability of an Asynchronous Learning Forum on Mobile Devices

ERIC Educational Resources Information Center

Chang, Chih-Kai

2010-01-01

Mobile learning has recently become noteworthy because mobile devices have become popular. To construct an asynchronous learning forum on mobile devices is important because an asynchronous learning forum is always an essential part of networked asynchronous distance learning. However, the input interface in handheld learning devices, which is…

A review of the use of handheld computers in medical nutrition.

PubMed

Holubar, Stefan; Harvey-Banchik, Lillian

2007-08-01

Handheld computers, or personal digital assistants (PDAs), have been used to assist clinicians in medical nutrition since the early 1980s. The term PDA was originally applied to programmable calculators; over time, the capabilities of these devices were expanded to allow for the use of more complicated programs such as databases, spreadsheets, and electronic books. Slowly, the device evolved into what is more commonly thought of as a PDA, that is, a device such as a PalmOS (PalmSource, Inc, Tokyo, Japan) or PocketPC (Microsoft, Redmond, WA) unit. We present a review of the literature about the use of PDAs in medical nutrition, followed by a discussion of the different types of PDAs and mobile technologies that are commercially available. This is followed by a discussion of software applications that are currently available for use by nutrition clinicians, focusing on freeware applications. Finally, future technologies and applications are discussed.

Prediction of essential oil content of oregano by hand-held and Fourier transform NIR spectroscopy.

PubMed

Camps, Cédric; Gérard, Marianne; Quennoz, Mélanie; Brabant, Cécile; Oberson, Carine; Simonnet, Xavier

2014-05-01

In the framework of a breeding programme, the analysis of hundreds of oregano samples to determine their essential oil content (EOC) is time-consuming and expensive in terms of labour. Therefore developing a new method that is rapid, accurate and less expensive to use would be an asset to breeders. The aim of the present study was to develop a method based on near-inrared (NIR) spectroscopy to determine the EOC of oregano dried powder. Two spectroscopic approaches were compared, the first using a hand-held NIR device and the second a Fourier transform (FT) NIR spectrometer. Hand-held NIR (1000-1800 nm) measurements and partial least squares regression allowed the determination of EOC with R² and SEP values of 0.58 and 0.81 mL per 100 g dry matter (DM) respectively. Measurements with FT-NIR (1000-2500 nm) allowed the determination of EOC with R² and SEP values of 0.91 and 0.68 mL per 100 g DM respectively. RPD, RER and RPIQ values for the model implemented with FT-NIR data were satisfactory for screening application, while those obtained with hand-held NIR data were below the level required to consider the model as enough accurate for screening application. The FT-NIR approach allowed the development of an accurate model for EOC prediction. Although the hand-held NIR approach is promising, it needs additional development before it can be used in practice. © 2013 Society of Chemical Industry.

Fiber optic tracheal detection device

NASA Astrophysics Data System (ADS)

Souhan, Brian E.; Nawn, Corinne D.; Shmel, Richard; Watts, Krista L.; Ingold, Kirk A.

2017-02-01

Poorly performed airway management procedures can lead to a wide variety of adverse events, such as laryngeal trauma, stenosis, cardiac arrest, hypoxemia, or death as in the case of failed airway management or intubation of the esophagus. Current methods for confirming tracheal placement, such as auscultation, direct visualization or capnography, may be subjective, compromised due to clinical presentation or require additional specialized equipment that is not always readily available during the procedure. Consequently, there exists a need for a non-visual detection mechanism for confirming successful airway placement that can give the provider rapid feedback during the procedure. Based upon our previously presented work characterizing the reflectance spectra of tracheal and esophageal tissue, we developed a fiber-optic prototype to detect the unique spectral characteristics of tracheal tissue. Device performance was tested by its ability to differentiate ex vivo samples of tracheal and esophageal tissue. Pig tissue samples were tested with the larynx, trachea and esophagus intact as well as excised and mounted on cork. The device positively detected tracheal tissue 18 out of 19 trials and 1 false positive out of 19 esophageal trials. Our proof of concept device shows great promise as a potential mechanism for rapid user feedback during airway management procedures to confirm tracheal placement. Ongoing studies will investigate device optimizations of the probe for more refined sensing and in vivo testing.

Parafoveal retinal cone mosaic imaging in children with ultra-compact switchable SLO/OCT handheld probe (Conference Presentation)

NASA Astrophysics Data System (ADS)

LaRocca, Francesco; Nankivil, Derek; DuBose, Theodore B.; Toth, Cynthia A.; Farsiu, Sina; Izatt, Joseph A.

2016-03-01

In vivo photoreceptor imaging has enhanced the way vision scientists and ophthalmologists understand the retinal structure, function, and etiology of numerous retinal pathologies. However, the complexity and large footprint of current systems capable of resolving photoreceptors has limited imaging to patients who are able to sit in an upright position and fixate for several minutes. Unfortunately, this excludes an important fraction of patients including bedridden patients, small children, and infants. Here, we show that our dual-modality, high-resolution handheld probe with a weight of only 94 g is capable of visualizing photoreceptors in supine children. Our device utilizes a microelectromechanical systems (MEMS) scanner and a novel telescope design to achieve over an order of magnitude reduction in size compared to similar systems. The probe has a 7° field of view and a lateral resolution of 8 µm. The optical coherence tomography (OCT) system has an axial resolution of 7 µm and a sensitivity of 101 dB. High definition scanning laser ophthalmoscopy (SLO) and OCT images were acquired from children ranging from 14 months to 12 years of age with and without pathology during examination under anesthesia in the operating room. Parafoveal cone imaging was shown using the SLO arm of this device without adaptive optics using a 3° FOV for the first time in children under 4 years old. This work lays the foundation for pediatric research, which will improve understanding of retinal development, maldevelopment and early onset of diseases at the cellular level during the beginning stages of human growth.

Stand-alone scattering optical device using holographic photopolymer (Conference Presentation)

NASA Astrophysics Data System (ADS)

Park, Jongchan; Lee, KyeoReh; Park, YongKeun

2016-03-01

When a light propagates through highly disordered medium, its optical parameters such as amplitude, phase and polarization states are completely scrambled because of multiple scattering events. Since the multiple scattering is a fundamental optical process that contains extremely high degrees of freedom, optical information of a transmitted light is totally mingled. Until recently, the presence of multiple scattering in an inhomogeneous medium is considered as a major obstacle when manipulating a light transmitting through the medium. However, a recent development of wavefront shaping techniques enable us to control the propagation of light through turbid media; a light transmitting through a turbid medium can be effectively controlled by modulating the spatial profile of the incident light using spatial light modulator. In this work, stand-alone scattering optical device is proposed; a holographic photopolymer film, which is much economic compared to the other digital spatial light modulators, is used to record and reconstruct permanent wavefront to generate optical field behind a scattering medium. By employing our method, arbitrary optical field can be generated since the scattering medium completely mixes all the optical parameters which allow us to access all the optical information only by modulating spatial phase profile of the impinging wavefront. The method is experimentally demonstrated in both the far-field and near-field regime where it shows promising fidelity and stability. The proposed stand-alone scattering optical device will opens up new avenues for exploiting the randomness inherent in disordered medium.

Validity and reliability of isometric muscle strength measurements of hip abduction and abduction with external hip rotation in a bent-hip position using a handheld dynamometer with a belt.

PubMed

Aramaki, Hidefumi; Katoh, Munenori; Hiiragi, Yukinobu; Kawasaki, Tsubasa; Kurihara, Tomohisa; Ohmi, Yorikatsu

2016-07-01

[Purpose] This study aimed to investigate the relatedness, reliability, and validity of isometric muscle strength measurements of hip abduction and abduction with an external hip rotation in a bent-hip position using a handheld dynamometer with a belt. [Subjects and Methods] Twenty healthy young adults, with a mean age of 21.5 ± 0.6 years were included. Isometric hip muscle strength in the subjects' right legs was measured under two posture positions using two devices: a handheld dynamometer with a belt and an isokinetic dynamometer. Reliability was evaluated using an intra-class correlation coefficient (ICC); relatedness and validity were evaluated using Pearson's product moment correlation coefficient. Differences in measurements of devices were assessed by two-way ANOVA. [Results] ICC (1, 1) was ≥0.9; significant positive correlations in measurements were found between the two devices under both conditions. No main effect was found between the measurement values. [Conclusion] Our findings revealed that there was relatedness, reliability, and validity of this method for isometric muscle strength measurements using a handheld dynamometer with a belt.

Nanocoaxes for Optical and Electronic Devices

PubMed Central

Rizal, Binod; Merlo, Juan M.; Burns, Michael J.; Chiles, Thomas C.; Naughton, Michael J.

2014-01-01

The evolution of micro/nanoelectronics technology, including the shrinking of devices and integrated circuit components, has included the miniaturization of linear and coaxial structures to micro/nanoscale dimensions. This reduction in the size of coaxial structures may offer advantages to existing technologies and benefit the exploration and development of new technologies. The reduction in the size of coaxial structures has been realized with various permutations between metals, semiconductors and dielectrics for the core, shield, and annulus. This review will focus on fabrication schemes of arrays of metal – nonmetal – metal nanocoax structures using non-template and template methods, followed by possible applications. The performance and scientific advantages associated with nanocoax-based optical devices including waveguides, negative refractive index materials, light emitting diodes, and photovoltaics are presented. In addition, benefits and challenges that accrue from the application of novel nanocoax structures in energy storage, electronic and sensing devices are summarized. PMID:25279400

Scale factor gage for fiber optics inspection device

NASA Technical Reports Server (NTRS)

Mcmahon, W.; Sugg, F. E.

1971-01-01

Flexible wire device, fastened along outside of fiber bundle from viewing portion to tip, positions calibrated adjustable gage in field of view. Scale factor is determined from known magnification characteristics of fiber optics system or from graduations on gage tip.

A novel fully integrated handheld gamma camera

NASA Astrophysics Data System (ADS)

Massari, R.; Ucci, A.; Campisi, C.; Scopinaro, F.; Soluri, A.

2016-10-01

In this paper, we present an innovative, fully integrated handheld gamma camera, namely designed to gather in the same device the gamma ray detector with the display and the embedded computing system. The low power consumption allows the prototype to be battery operated. To be useful in radioguided surgery, an intraoperative gamma camera must be very easy to handle since it must be moved to find a suitable view. Consequently, we have developed the first prototype of a fully integrated, compact and lightweight gamma camera for radiopharmaceuticals fast imaging. The device can operate without cables across the sterile field, so it may be easily used in the operating theater for radioguided surgery. The prototype proposed consists of a Silicon Photomultiplier (SiPM) array coupled with a proprietary scintillation structure based on CsI(Tl) crystals. To read the SiPM output signals, we have developed a very low power readout electronics and a dedicated analog to digital conversion system. One of the most critical aspects we faced designing the prototype was the low power consumption, which is mandatory to develop a battery operated device. We have applied this detection device in the lymphoscintigraphy technique (sentinel lymph node mapping) comparing the results obtained with those of a commercial gamma camera (Philips SKYLight). The results obtained confirm a rapid response of the device and an adequate spatial resolution for the use in the scintigraphic imaging. This work confirms the feasibility of a small gamma camera with an integrated display. This device is designed for radioguided surgery and small organ imaging, but it could be easily combined into surgical navigation systems.

Handheld computers for survey and trial data collection in resource-poor settings: development and evaluation of PDACT, a Palm Pilot interviewing system.

PubMed

Seebregts, Christopher J; Zwarenstein, Merrick; Mathews, Catherine; Fairall, Lara; Flisher, Alan J; Seebregts, Clive; Mukoma, Wanjiru; Klepp, Knut-Inge

2009-11-01

Handheld computers (personal digital assistant, PDA) have the potential to reduce the logistic burden, cost, and error rate of paper-based health research data collection, but there is a lack of appropriate software. The present work describes the development and evaluation of PDACT, a Personal Data Collection Toolset (www.healthware.org/pdact/index.htm) for the Palm Pilot handheld computer for interviewer-administered and respondent-administered data collection. We developed Personal Data Collection Toolkit (PDACT) software to enable questionnaires developed in QDS Design Studio, a Windows application, to be compiled and completed on Palm Pilot devices and evaluated in several representative field survey settings. The software has been used in seven separate studies and in over 90,000 interviews. Five interviewer-administered studies were completed in rural settings with poor communications infrastructure, following one day of interviewer training. Two respondent-administered questionnaire studies were completed by learners, in urban secondary schools, after 15min training. Questionnaires were available on each handheld in up to 11 languages, ranged from 20 to 580 questions, and took between 15 and 90min to complete. Up to 200 Palm Pilot devices were in use on a single day and, in about 50 device-years of use, very few technical problems were found. Compared with paper-based collection, data validation and cleaning times were reduced, and fewer errors were found. PDA data collection is easy to use and preferred by interviewers and respondents (both respondent-administered and interviewer-administered) over paper. Data are compiled and available within hours of collection facilitating data quality assurance. Although hardware increases the setup cost of the first study, the cumulative cost falls thereafter, and converges on the cumulative cost of paper-based studies (four, in the case of our interviewer-administered studies). Handheld data collection is an

Graphene electrodes for lithium-niobate electro-optic devices.

PubMed

Chang, Zeshan; Jin, Wei; Chiang, Kin Seng

2018-04-15

We propose and demonstrate the use of graphene electrodes for lithium-niobate electro-optic (EO) devices to exempt the need of incorporating a buffer layer between the waveguide and the electrodes. Using graphene electrodes, our experimental mode converter, based on an EO-generated long-period grating in a LiNbO 3 waveguide, shows a reduction in the half-π voltage by almost three times, compared with the conventional electrode design using metal. With the buffer layer exempted, the device fabrication process is also significantly simplified. The use of graphene electrodes is an effective approach to enhancing the efficiency of EO devices and, at the same time, reducing their fabrication cost.

A sensitive, handheld vapor sensor based on microcantilevers

NASA Astrophysics Data System (ADS)

Pinnaduwage, L. A.; Hedden, D. L.; Gehl, A.; Boiadjiev, V. I.; Hawk, J. E.; Farahi, R. H.; Thundat, T.; Houser, E. J.; Stepnowski, S.; McGill, R. A.; Deel, L.; Lareau, R. T.

2004-11-01

We report the development of a handheld sensor based on piezoresistive microcantilevers that does not depend on optical detection, yet has high detection sensitivity. The sensor is able to detect vapors from the plastic explosives pentaerythritol tetranitrate and hexahydro-1,3,5-triazine at levels below 10 parts per trillion within few seconds of exposure under ambient conditions. A differential measurement technique has yielded a rugged sensor that is unaffected by vibration and is able to function as a "sniffer." The microelectromechanical system sensor design allows for the incorporation of hundreds of microcantilevers with suitable coatings in order to achieve sufficient selectivity in the future, and thus could provide an inexpensive, unique platform for the detection of chemical, biological, and explosive materials.

Multi-scale theory-assisted nano-engineering of plasmonic-organic hybrid electro-optic device performance

NASA Astrophysics Data System (ADS)

Elder, Delwin L.; Johnson, Lewis E.; Tillack, Andreas F.; Robinson, Bruce H.; Haffner, Christian; Heni, Wolfgang; Hoessbacher, Claudia; Fedoryshyn, Yuriy; Salamin, Yannick; Baeuerle, Benedikt; Josten, Arne; Ayata, Masafumi; Koch, Ueli; Leuthold, Juerg; Dalton, Larry R.

2018-02-01

Multi-scale (correlated quantum and statistical mechanics) modeling methods have been advanced and employed to guide the improvement of organic electro-optic (OEO) materials, including by analyzing electric field poling induced electro-optic activity in nanoscopic plasmonic-organic hybrid (POH) waveguide devices. The analysis of in-device electro-optic activity emphasizes the importance of considering both the details of intermolecular interactions within organic electro-optic materials and interactions at interfaces between OEO materials and device architectures. Dramatic improvement in electro-optic device performance-including voltage-length performance, bandwidth, energy efficiency, and lower optical losses have been realized. These improvements are critical to applications in telecommunications, computing, sensor technology, and metrology. Multi-scale modeling methods illustrate the complexity of improving the electro-optic activity of organic materials, including the necessity of considering the trade-off between improving poling-induced acentric order through chromophore modification and the reduction of chromophore number density associated with such modification. Computational simulations also emphasize the importance of developing chromophore modifications that serve multiple purposes including matrix hardening for enhanced thermal and photochemical stability, control of matrix dimensionality, influence on material viscoelasticity, improvement of chromophore molecular hyperpolarizability, control of material dielectric permittivity and index of refraction properties, and control of material conductance. Consideration of new device architectures is critical to the implementation of chipscale integration of electronics and photonics and achieving the high bandwidths for applications such as next generation (e.g., 5G) telecommunications.

A simple handheld pupillometer for chromatic Flicker studies

NASA Astrophysics Data System (ADS)

Bernabei, M.; Tinarelli, R.; Peretto, L.; Rovati, L.

2014-02-01

A portable pupillometer has been developed which is capable of performing accurate measurements of the pupil diameter during chromatic flicker stimulations. The handheld measuring system records the near-infrared image of the pupil at the rate of 25 fps and simultaneously stimulates the eye using a diffused flicker light generated by light emitting diodes (LEDs). Intensity, frequency and chromatic coordinates of the stimulus can be easily adjusted using a user-friendly graphical interface. Thanks to a chromatic monitoring of the stimulus close to the plane of the eye, photopically matched conditions can be easily achieved. The pupil diameter/area can be measured during flickering stimuli that are generated with frequency in a range of 0.1-20 Hz. The electronic unit, properly connected to the personal computer through a USB port, drives the optical unit, which can be easily held in a hand. The software interface controlling the system was developed in LabVIEW. This paper describes the instrument optical setup, front-end electronics and data processing. Moreover preliminary results obtained on a voluntary are reported.

Effects of a Driver Cellphone Ban on Overall, Handheld, and Hands-Free Cellphone Use While Driving: New Evidence from Canada.

PubMed

Carpenter, Christopher S; Nguyen, Hai V

2015-11-01

We provide new evidence on the effects of increasingly common driver cellphone bans on self-reported overall, handheld, and hands-free cellphone use while driving by studying Ontario, Canada, which instituted a 3-month education campaign in November 2009 followed by a binding driver cellphone ban in February 2010. Using residents of Alberta as a control group in a difference-in-differences framework, we find visual and regression-based evidence that Ontario's cellphone ban significantly reduced overall and handheld cellphone use. We also find that the policies significantly increased hands-free cellphone use. The reductions in overall and handheld use are driven exclusively by women, whereas the increases in hands-free use are much larger for men. Our results provide the first direct evidence that cellphone bans have the unintended effect of inducing substitution to hands-free devices. Copyright © 2014 John Wiley & Sons, Ltd.

Fiber optic device for sensing the presence of a gas

DOEpatents

Benson, D.K.; Bechinger, C.S.; Tracy, C.E.

1998-01-13

A fiber-optic device for sensing the presence of a gas in an environment is provided. The device comprises a light source for directing a light beam to a layer system having a first surface and a second surface opposite the first surface. The first surface is exposable to the light beam and the second surface is exposable to the environment. A first light portion encounters and reflects from the first surface at an angle of incidence free from optical wave guide resonance phenomenon and the second light portion encounters and reflects from the first surface at an angle of incidence enabling an optical wave guide resonance phenomenon. The layer system is selected to reversibly react with the gas to be detected. The reaction between the gas and the material changes the material`s optical properties and the wavelength at which the optical wave guide resonance occurs. Furthermore, a mechanism for measuring the intensity of the reflected first light portion relative to the reflected second light portion is provided with the ratio of the first and second light portions indicating the concentration of the gas presence in the environment. 5 figs.

Fiber optic device for sensing the presence of a gas

DOEpatents

Benson, David K.; Bechinger, Clemens S.; Tracy, C. Edwin

1998-01-01

A fiber-optic device for sensing the presence of a gas in an environment is provided. The device comprises a light source for directing a light beam to a layer system having a first surface and a second surface opposite the first surface. The first surface is exposable to the light beam and the second surface is exposable to the environment. A first light portion encounters and reflects from the first surface at an angle of incidence free from optical wave guide resonance phenomenon and the second light portion encounters and reflects from the first surface at an angle of incidence enabling an optical wave guide resonance phenomenon. The layer system is selected to reversibly react with the gas to be detected. The reaction between the gas and the material changes the material's optical properties and the wavelength at which the optical wave guide resonance occurs. Furthermore, a mechanism for measuring the intensity of the reflected first light portion relative to the reflected second light portion is provided with the ratio of the first and second light portions indicating the concentration of the gas presence in the environment.

Applicability of a Diffuse Reflectance Infrared Fourier Transform handheld spectrometer to perform in situ analyses on Cultural Heritage materials

NASA Astrophysics Data System (ADS)

Arrizabalaga, Iker; Gómez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

2014-08-01

This work studies the applicability of a Diffuse Reflectance Infrared Fourier Transform handheld device to perform in situ analyses on Cultural Heritage assets. This portable diffuse reflectance spectrometer has been used to characterise and diagnose the conservation state of (a) building materials of the Guevara Palace (15th century, Segura, Basque Country, Spain) and (b) different 19th century wallpapers manufactured by the Santa Isabel factory (Vitoria-Gasteiz, Basque Country, Spain) and by the well known Dufour and Leroy manufacturers (Paris, France), all of them belonging to the Torre de los Varona Castle (Villanañe, Basque Country, Spain). In all cases, in situ measurements were carried out and also a few samples were collected and measured in the laboratory by diffuse reflectance spectroscopy (DRIFT) in order to validate the information obtained by the handheld instrument. In the analyses performed in situ, distortions in the diffuse reflectance spectra can be observed due to the presence of specular reflection, showing the inverted bands caused by the Reststrahlen effect, in particular on those IR bands with the highest absorption coefficients. This paper concludes that the results obtained in situ by a diffuse reflectance handheld device are comparable to those obtained with laboratory diffuse reflectance spectroscopy equipment and proposes a few guidelines to acquire good spectra in the field, minimising the influence caused by the specular reflection.

Accessible virtual reality therapy using portable media devices.

PubMed

Bruck, Susan; Watters, Paul A

2010-01-01

Simulated immersive environments displayed on large screens are a valuable therapeutic asset in the treatment of a range of psychological disorders. Permanent environments are expensive to build and maintain, require specialized clinician training and technical support and often have limited accessibility for clients. Ideally, virtual reality exposure therapy (VRET) could be accessible to the broader community if we could use inexpensive hardware with specifically designed software. This study tested whether watching a handheld non-immersive media device causes nausea and other cybersickness responses. Using a repeated measure design we found that nausea, general discomfort, eyestrain, blurred vision and an increase in salivation significantly increased in response to handheld non-immersive media device exposure.

High Performance Hermetic Package For LiNbO3 Electro-Optic Waveguide Devices

NASA Astrophysics Data System (ADS)

Preston, K. R.; Macdonald, B. M.; Harmon, R. A.; Ford, C. W.; Shaw, R. N.; Reid, I.; Davidson, J. H.; Beaumont, A. R.; Booth, R. C.

1989-02-01

A high performance fibre-tailed package for LiNbO3 electro-optic waveguide devices is described. The package is based around a hermetic metal submodule which contains no epoxy or other organic materials. The LiNbO3 chip is mounted using a soldering technique, and laser welding is used for fibre fixing to give stable, low loss optical coupling to single mode fibres. Optical reflections are minimised by the use of antireflective coatings on the fibre ends and waveguide facets. High speed electrical connections are made via coplanar glass-sealed leadthroughs to LiNb03 travelling wave devices, and packaged device operation to frequencies in excess of 4GHz is demonstrated.

CMOS-based optical energy harvesting circuit for biomedical and Internet of Things devices

NASA Astrophysics Data System (ADS)

Nattakarn, Wuthibenjaphonchai; Ishizu, Takaaki; Haruta, Makito; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Sawan, Mohamad; Ohta, Jun

2018-04-01

In this work, we present a novel CMOS-based optical energy harvesting technology for implantable and Internet of Things (IoT) devices. In the proposed system, a CMOS energy-harvesting circuit accumulates a small amount of photoelectrically converted energy in an external capacitor, and intermittently supplies this power to a target device. Two optical energy-harvesting circuit types were implemented and evaluated. Furthermore, we developed a photoelectrically powered optical identification (ID) circuit that is suitable for IoT technology applications.

Femtosecond Laser Microfabrication of an Integrated Device for Optical Release and Sensing of Bioactive Compounds.

PubMed

Ghezzi, Diego; Vazquez, Rebeca Martinez; Osellame, Roberto; Valtorta, Flavia; Pedrocchi, Alessandra; Valle, Giuseppe Della; Ramponi, Roberta; Ferrigno, Giancarlo; Cerullo, Giulio

2008-10-23

Flash photolysis of caged compounds is one of the most powerful approaches to investigate the dynamic response of living cells. Monolithically integrated devices suitable for optical uncaging are in great demand since they greatly simplify the experiments and allow their automation. Here we demonstrate the fabrication of an integrated bio-photonic device for the optical release of caged compounds. Such a device is fabricated using femtosecond laser micromachining of a glass substrate. More in detail, femtosecond lasers are used both to cut the substrate in order to create a pit for cell growth and to inscribe optical waveguides for spatially selective uncaging of the compounds present in the culture medium. The operation of this monolithic bio-photonic device is tested using both free and caged fluorescent compounds to probe its capability of multipoint release and optical sensing. Application of this device to the study of neuronal network activity can be envisaged.

Use of handheld computers in clinical practice: a systematic review.

PubMed

Mickan, Sharon; Atherton, Helen; Roberts, Nia Wyn; Heneghan, Carl; Tilson, Julie K

2014-07-06

Many healthcare professionals use smartphones and tablets to inform patient care. Contemporary research suggests that handheld computers may support aspects of clinical diagnosis and management. This systematic review was designed to synthesise high quality evidence to answer the question; Does healthcare professionals' use of handheld computers improve their access to information and support clinical decision making at the point of care? A detailed search was conducted using Cochrane, MEDLINE, EMBASE, PsycINFO, Science and Social Science Citation Indices since 2001. Interventions promoting healthcare professionals seeking information or making clinical decisions using handheld computers were included. Classroom learning and the use of laptop computers were excluded. Two authors independently selected studies, assessed quality using the Cochrane Risk of Bias tool and extracted data. High levels of data heterogeneity negated statistical synthesis. Instead, evidence for effectiveness was summarised narratively, according to each study's aim for assessing the impact of handheld computer use. We included seven randomised trials investigating medical or nursing staffs' use of Personal Digital Assistants. Effectiveness was demonstrated across three distinct functions that emerged from the data: accessing information for clinical knowledge, adherence to guidelines and diagnostic decision making. When healthcare professionals used handheld computers to access clinical information, their knowledge improved significantly more than peers who used paper resources. When clinical guideline recommendations were presented on handheld computers, clinicians made significantly safer prescribing decisions and adhered more closely to recommendations than peers using paper resources. Finally, healthcare professionals made significantly more appropriate diagnostic decisions using clinical decision making tools on handheld computers compared to colleagues who did not have access to these

Use of handheld computers in clinical practice: a systematic review

PubMed Central

2014-01-01

Background Many healthcare professionals use smartphones and tablets to inform patient care. Contemporary research suggests that handheld computers may support aspects of clinical diagnosis and management. This systematic review was designed to synthesise high quality evidence to answer the question; Does healthcare professionals’ use of handheld computers improve their access to information and support clinical decision making at the point of care? Methods A detailed search was conducted using Cochrane, MEDLINE, EMBASE, PsycINFO, Science and Social Science Citation Indices since 2001. Interventions promoting healthcare professionals seeking information or making clinical decisions using handheld computers were included. Classroom learning and the use of laptop computers were excluded. Two authors independently selected studies, assessed quality using the Cochrane Risk of Bias tool and extracted data. High levels of data heterogeneity negated statistical synthesis. Instead, evidence for effectiveness was summarised narratively, according to each study’s aim for assessing the impact of handheld computer use. Results We included seven randomised trials investigating medical or nursing staffs’ use of Personal Digital Assistants. Effectiveness was demonstrated across three distinct functions that emerged from the data: accessing information for clinical knowledge, adherence to guidelines and diagnostic decision making. When healthcare professionals used handheld computers to access clinical information, their knowledge improved significantly more than peers who used paper resources. When clinical guideline recommendations were presented on handheld computers, clinicians made significantly safer prescribing decisions and adhered more closely to recommendations than peers using paper resources. Finally, healthcare professionals made significantly more appropriate diagnostic decisions using clinical decision making tools on handheld computers compared to colleagues

Active functional devices using parity-time symmetry optics (Conference Presentation)

NASA Astrophysics Data System (ADS)

Brac de la Perriere, Vincent; Benisty, Henri; Ramdane, Abderrahim; Lupu, Anatole

2017-05-01

The progress of nanotechnologies has triggered the emergence of many photonic artificial structures: photonic crystals, metamaterials, plasmonic resonators. Recently the intriguing class of PT-symmetric devices, referring to Parity-Time symmetry [1] has attracted much attention. The characteristic feature of PT-symmetry is that the structures' refractive index profile is complex-valued due to the presence of alternating gain and loss regions in the system. Apart from fundamental research motivations, the tremendous interest in these artificial systems is strongly driven by the practical outcomes expected to foster a new generation of tunable, reconfigurable and non-reciprocal devices. The principle of gain-loss modulation lying in the heart of PT-symmetry optics enables a range of innovative solutions in the field of integrated optics at 1.5μm [2-7]. By using PT-symmetric coupled waveguides and Bragg reflectors as fundamental building blocks, it is possible to build a wide variety of functional optical devices. The PT-symmetry principle provides an alternative way for the realization of active devices that could become functional in a new platform for integrated optics. For instance one major bottleneck of the III-V/Si hybrid integration approach is that each type of active devices (laser, modulator, etc) requires a specific composition of III-V semiconductor alloy, involving a variety of (re)growth challenges. The advantage of the PT-symmetry solution is that the fabrication of all these devices can be done with a single stack of III-V semiconductor alloys that greatly simplifies the technological process. The aim of the current contribution is to provide a survey of the most promising applications of PT-symmetry in photonics with a particular emphases on the transition from theoretical concepts to experimental devices. The intention is to draw attention to the risks and issues related to the practical implementation that are most often overlooked in the basic

Evaluation of polymer based third order nonlinear integrated optics devices

NASA Astrophysics Data System (ADS)

Driessen, A.; Hoekstra, H. J. W. M.; Blom, F. C.; Horst, F.; Krijnen, G. J. M.; van Schoot, J. B. P.; Lambeck, P. V.; Popma, Th. J. A.; Diemeer, M. B.

1998-01-01

Nonlinear polymers are promising materials for high speed active integrated optics devices. In this paper we evaluate the perspectives polymer based nonlinear optical devices can offer. Special attention is directed to the materials aspects. In our experimental work we applied mainly Akzo Nobel DANS side-chain polymer that exhibits large second and third order coefficients. This material has been characterized by third harmonic generation, z-scan and pump-probe measurements. In addition, various waveguiding structures have been used to measure the nonlinear absorption (two photon absorption) on a ps time-scale. Finally an integrated optics Mach Zehnder interferometer has been realized and evaluated. It is shown that the DANS side-chain polymer has many of the desired properties: the material is easily processable in high-quality optical waveguiding structures, has low linear absorption and its nonlinearity has a pure electronic origin. More materials research has to be done to arrive at materials with higher nonlinear coefficients to allow switching at moderate light intensity ( < 1 W peak power) and also with lower nonlinear absorption coefficients.

Schools Going Mobile: A Study of the Adoption of Mobile Handheld Technologies in Western Australian Independent Schools

ERIC Educational Resources Information Center

Pegrum, Mark; Oakley, Grace; Faulkner, Robert

2013-01-01

This paper reports on the adoption of mobile handheld technologies in ten Western Australian independent schools, based on interviews with staff conducted in 2011. iPads were the most popular device, followed by iPod Touches and iPhones. Class sets were common at lower levels, with 1:1 models becoming increasingly common at higher levels. Mobile…

A biometric access personal optical storage device

NASA Astrophysics Data System (ADS)

Davies, David H.; Ray, Steve; Gurkowski, Mark; Lee, Lane

2007-01-01

A portable USB2.0 personal storage device that uses built-in encryption and allows data access through biometric scanning of a finger print is described. Biometric image derived templates are stored on the removable 32 mm write once (WO) media. The encrypted templates travel with the disc and allow access to the data providing the biometric feature (e.g. the finger itself) is present. The device also allows for export and import of the templates under secure key exchange protocols. The storage system is built around the small form factor optical engine that uses a tilt arm rotary actuator and front surface media.

Optomechanical measurement of photon spin angular momentum and optical torque in integrated photonic devices.

PubMed

He, Li; Li, Huan; Li, Mo

2016-09-01

Photons carry linear momentum and spin angular momentum when circularly or elliptically polarized. During light-matter interaction, transfer of linear momentum leads to optical forces, whereas transfer of angular momentum induces optical torque. Optical forces including radiation pressure and gradient forces have long been used in optical tweezers and laser cooling. In nanophotonic devices, optical forces can be significantly enhanced, leading to unprecedented optomechanical effects in both classical and quantum regimes. In contrast, to date, the angular momentum of light and the optical torque effect have only been used in optical tweezers but remain unexplored in integrated photonics. We demonstrate the measurement of the spin angular momentum of photons propagating in a birefringent waveguide and the use of optical torque to actuate rotational motion of an optomechanical device. We show that the sign and magnitude of the optical torque are determined by the photon polarization states that are synthesized on the chip. Our study reveals the mechanical effect of photon's polarization degree of freedom and demonstrates its control in integrated photonic devices. Exploiting optical torque and optomechanical interaction with photon angular momentum can lead to torsional cavity optomechanics and optomechanical photon spin-orbit coupling, as well as applications such as optomechanical gyroscopes and torsional magnetometry.

Optomechanical measurement of photon spin angular momentum and optical torque in integrated photonic devices

PubMed Central

He, Li; Li, Huan; Li, Mo

2016-01-01

Photons carry linear momentum and spin angular momentum when circularly or elliptically polarized. During light-matter interaction, transfer of linear momentum leads to optical forces, whereas transfer of angular momentum induces optical torque. Optical forces including radiation pressure and gradient forces have long been used in optical tweezers and laser cooling. In nanophotonic devices, optical forces can be significantly enhanced, leading to unprecedented optomechanical effects in both classical and quantum regimes. In contrast, to date, the angular momentum of light and the optical torque effect have only been used in optical tweezers but remain unexplored in integrated photonics. We demonstrate the measurement of the spin angular momentum of photons propagating in a birefringent waveguide and the use of optical torque to actuate rotational motion of an optomechanical device. We show that the sign and magnitude of the optical torque are determined by the photon polarization states that are synthesized on the chip. Our study reveals the mechanical effect of photon’s polarization degree of freedom and demonstrates its control in integrated photonic devices. Exploiting optical torque and optomechanical interaction with photon angular momentum can lead to torsional cavity optomechanics and optomechanical photon spin-orbit coupling, as well as applications such as optomechanical gyroscopes and torsional magnetometry. PMID:27626072

Hand-held monitor of sympathetic nervous system using salivary amylase activity and its validation by driver fatigue assessment.

PubMed

Yamaguchi, Masaki; Deguchi, Mitsuo; Wakasugi, Junichi; Ono, Shin; Takai, Noriyasu; Higashi, Tomoyuki; Mizuno, Yasufumi

2006-01-15

In order to realize a hand-held monitor of the sympathetic nervous system, we fabricated a completely automated analytical system for salivary amylase activity using a dry-chemistry system. This was made possible by the fabrication of a disposable test-strip equipped with built-in collecting and reagent papers and an automatic saliva transfer device. In order to cancel out the effects of variations in environmental temperature and pH of saliva, temperature- and pH-adjusted equations were experimentally determined, and each theoretical value was input into the memory of the hand-held monitor. Within a range of salivary amylase activity between 10 and 140 kU/l, the calibration curve for the hand-held monitor showed a coefficient with R(2)=0.97. Accordingly, it was demonstrated that the hand-held monitor enabled a user to automatically measure the salivary amylase activity with high accuracy with only 30 microl sample of saliva within a minute from collection to completion of the measurement. In order to make individual variations of salivary amylase activity negligible during driver fatigue assessment, a normalized equation was proposed. The normalized salivary amylase activity correlated with the mental and physical fatigue states. Thus, this study demonstrated that an excellent hand-held monitor with an algorithm for normalization of individuals' differences in salivary amylase activity, which could be easily and quickly used for evaluating the activity of the sympathetic nervous system at any time. Furthermore, it is suggested that the salivary amylase activity might be used as a better index for psychological research.

Liquid crystal waveguides: new devices enabled by >1000 waves of optical phase control

NASA Astrophysics Data System (ADS)

Davis, Scott R.; Farca, George; Rommel, Scott D.; Johnson, Seth; Anderson, Michael H.

2010-02-01

A new electro-optic waveguide platform, which provides unprecedented voltage control over optical phase delays (> 2mm), with very low loss (< 0.5 dB/cm) and rapid response time (sub millisecond), will be presented. This technology, developed by Vescent Photonics, is based upon a unique liquid-crystal waveguide geometry, which exploits the tremendous electro-optic response of liquid crystals while circumventing their historic limitations. The waveguide geometry provides nematic relaxation speeds in the 10's of microseconds and LC scattering losses that are reduced by orders of magnitude from bulk transmissive LC optics. The exceedingly large optical phase delays accessible with this technology enable the design and construction of a new class of previously unrealizable photonic devices. Examples include: 2-D analog non-mechanical beamsteerers, chip-scale widely tunable lasers, chip-scale Fourier transform spectrometer (< 5 nm resolution demonstrated), widely tunable micro-ring resonators, tunable lenses, ultra-low power (< 5 microWatts) optical switches, true optical time delay devices for phased array antennas, and many more. All of these devices may benefit from established manufacturing technologies and ultimately may be as inexpensive as a calculator display. Furthermore, this new integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, FSO, laser illumination, phased array radar, etc. Performance attributes of several example devices and application data will be presented. In particular, we will present a non-mechanical beamsteerer that steers light in both the horizontal and vertical dimensions.

Optical tests for using smartphones inside medical devices

NASA Astrophysics Data System (ADS)

Bernat, Amir S.; Acobas, Jennifer K.; Phang, Ye Shang; Hassan, David; Bolton, Frank J.; Levitz, David

2018-02-01

Smartphones are currently used in many medical applications and are more frequently being integrated into medical imaging devices. The regulatory requirements in existence today however, particularly the standardization of smartphone imaging through validation and verification testing, only partially cover imaging characteristics with a smartphone. Specifically, it has been shown that smartphone camera specifications are of sufficient quality for medical imaging, and there are devices which comply with the FDA's regulatory requirements for a medical device such as a device's field of view, direction of viewing and optical resolution and optical distortion. However, these regulatory requirements do not call specifically for color testing. Images of the same object using automatic settings or different light sources can show different color composition. Experimental results showing such differences are presented. Under some circumstances, such differences in color composition could potentially lead to incorrect diagnoses. It is therefore critical to control the smartphone camera and illumination parameters properly. This paper examines different smartphone camera settings that affect image quality and color composition. To test and select the correct settings, a test methodology is proposed. It aims at evaluating and testing image color correctness and white balance settings for mobile phones and LED light sources. Emphasis is placed on color consistency and deviation from gray values, specifically by evaluating the ΔC values based on the CIEL*a*b* color space. Results show that such standardization minimizes differences in color composition and thus could reduce the risk of a wrong diagnosis.

Femtosecond Laser Microfabrication of an Integrated Device for Optical Release and Sensing of Bioactive Compounds

PubMed Central

Ghezzi, Diego; Vazquez, Rebeca Martinez; Osellame, Roberto; Valtorta, Flavia; Pedrocchi, Alessandra; Valle, Giuseppe Della; Ramponi, Roberta; Ferrigno, Giancarlo; Cerullo, Giulio

2008-01-01

Flash photolysis of caged compounds is one of the most powerful approaches to investigate the dynamic response of living cells. Monolithically integrated devices suitable for optical uncaging are in great demand since they greatly simplify the experiments and allow their automation. Here we demonstrate the fabrication of an integrated bio-photonic device for the optical release of caged compounds. Such a device is fabricated using femtosecond laser micromachining of a glass substrate. More in detail, femtosecond lasers are used both to cut the substrate in order to create a pit for cell growth and to inscribe optical waveguides for spatially selective uncaging of the compounds present in the culture medium. The operation of this monolithic bio-photonic device is tested using both free and caged fluorescent compounds to probe its capability of multipoint release and optical sensing. Application of this device to the study of neuronal network activity can be envisaged. PMID:27873888

Novel wearable-type biometric devices based on skin tissue optics with multispectral LED-photodiode matrix

NASA Astrophysics Data System (ADS)

Jo, Young Chang; Kim, Hae Na; Kang, Jae Hwan; Hong, Hyuck Ki; Choi, Yeon Shik; Jung, Suk Won; Kim, Sung Phil

2017-04-01

In this study, we examined the possibility of using a multispectral skin photomatrix (MSP) module as a novel biometric device. The MSP device measures optical patterns of the wrist skin tissue. Optical patterns consist of 2 × 8 photocurrent intensities of photodiode arrays, which are generated by optical transmission and diffuse reflection of photons from LED light sources with variable wavelengths into the wrist skin tissue. Optical patterns detected by the MSP device provide information on both the surface and subsurface characteristics of the human skin tissue. We found that in the 21 subjects we studied, they showed their unique characteristics, as determined using several wavelengths of light. The experimental results show that the best personal identification accuracy can be acquired using a combination of infrared light and yellow light. This novel biometric device, the MSP module, exhibited an excellent false acceptance rate (FAR) of 0.3% and a false rejection rate (FRR) of 0.0%, which are better than those of commercialized biometric devices such as a fingerprint biometric system. From these experimental results, we found that people exhibit unique optical patterns of their inner-wrist skin tissue and this uniqueness could be used for developing novel high-accuracy personal identification devices.