Comparison of the Keeler Pulsair 2000 non-contact tonometer with Goldmann applanation.

Science.gov (United States)

Moseley, M J; Thompson, J R; Deutsch, J; Misson, G P; Naylor, G; Tan-Yee, A; Taylor, R H; Fielder, A R

1993-01-01

The Pulsair 2000 non-contact tonometer (Keeler Ltd, UK) is compared with the Goldmann applanation tonometer. Data from 80 eyes were acquired by four experienced observers. A linear regression analysis showed the relationship between the instruments to be: Pulsair = 0.66 + 0.95 Goldmann. Individual components of variation were analysed by analysis of variance which indicated a significant variation in the slope of the regression equation due to observers (p = 0.02) but not to the order in which topical anaesthesia was administered. Differences between two Pulsair instruments were of marginal significance (p = 0.07). The intercept of the regression equation was unaffected by any of the components of variation. Seventy-nine per cent of averaged intraocular pressure measurements obtained with the Pulsair 2000 fell on or within +/- 3 mmHg of those measured with the Goldmann tonometer. It is concluded that the Pulsair 2000 can provide clinically useful measurements of intraocular pressure.

The effect of repeated applanation on subsequent IOP measurements.

Science.gov (United States)

AlMubrad, Turki M; Ogbuehi, Kelechi C

2008-11-01

In studies aimed at assessing the accuracy and repeatability of non-contact tonometers, the order in which these tonometers and the Goldmann tonometer are used is usually randomised despite studies in the literature that demonstrate an ocular massage effect that occurs post-applanation but not after non-contact tonometry. The purpose of this study was to investigate the effect of repeated corneal applanation on subsequent assessments of IOP. Data were obtained from 65 left eyes of 65 young, oculovisual normals. Three sets of IOP measurements were obtained, one set with the Goldmann applanation tonometer and two with the Topcon CT80 non-contact tonometer (one set each before and after applanation with the Goldmann tonometer), in each one of two separate measurement sessions, one week apart. The average (and SD) IOP measured with the Goldmann tonometer in the first session (14.8+/-2.9 mmHg) did not vary significantly from the IOP measured with the non-contact tonometer (pre-applanation) in both sessions or with the average Goldmann IOP in the second session. The bias (mean difference +/- SD) between methods was 0.3+/-1.4 mmHg and 0.4+/-1.4 mmHg, respectively, for the first and second sessions, with the CT80 (pre-applanation) recording the higher IOP in both sessions. The within-session repeatability coefficients were +/-2.3 mmHg, +/-2.6 mmHg, +/-2.1 mmHg and +/-2.0 mmHg for the CT80 (pre-applanation) in the first and second sessions, and the Goldmann tonometer in the first and second sessions, respectively. Test-retest repeatability coefficients were +/-2.8 mmHg and +/-2.5 mmHg for the CT80 (pre-applanation) and the Goldmann tonometer respectively. Post-applanation with the Goldmann tonometer, there was a statistically significant (pcontact tonometer in both sessions. These results suggest that repeated corneal applanation leads to a statistically significant reduction in IOP on subsequent measurements.

Red-free light for measurement of intraocular pressure using Goldmann applanation tonometer without fluorescein.

Science.gov (United States)

Ghoneim, Ehab M

2014-01-01

To evaluate the use of red-free light for the measurement of intraocular pressure (IOP) using a Goldmann applanation tonometer without fluorescein. This cross-sectional study was carried out on 500 eyes in 250 patients attending the Ophthalmology Outpatient Clinic at Suez Canal University Hospital. The IOP was measured using a Goldmann applanation tonometer mounted on a Haag-Streit slit-lamp. The measurements were performed first using red-free light without fluorescein. Then the measurements were repeated with cobalt blue light and topical fluorescein on the same eyes. The mean IOP was 15.23 ± 3.3 (SD) mm Hg using the red-free light without fluorescein, whereas it was 15.78 ± 3.7 (SD) mm Hg when measured using cobalt blue light after the application of fluorescein to the conjunctival sac. This difference was not statistically significant. Measurement of IOP with a Goldmann applanationtonometer with red-free light and without the use of fluorescein is simple, saves time, and gives an accurate IOP measurement relative to the traditional measurement technique with cobalt blue light and topical fluorescein.

A clinical comparison of the Xpert non-contact tonometer with the Goldmann applanation tonometer after penetrating keratoplasty.

Science.gov (United States)

Lisle, C; Ehlers, N

2000-04-01

To assess the agreement between the Xpert non-contact tonometer (NCT) and the Goldmann applanation tonometer in patients who have undergone penetrating keratoplasty. The study material consisted of 42 consecutive patients (43 eyes) who had undergone penetrating keratoplasty within the previous 13 months. The slope of the linear relationship between the two measurement methods did not differ significantly from 1.0. The mean difference between the methods of 0.96 mmHg was not statistically significant. The range of intraindividual differences between the methods was from -9.8 to 22.8 mmHg. The standard deviation of differences was 6.62 mmHg. The 95% limits of agreement were -12.00 to 13.94 mmHg. There was no significant correlation between the central corneal thickness, astigmatism or transplant size and the difference between the methods The Xpert NCT shows considerable variation from the Goldmann values The degree of agreement with the true IOP value remains to be shown.

Comparison of three methods of tonometry in normal subjects: Goldmann applanation tonometer, non-contact airpuff tonometer, and Tono-Pen XL.

Science.gov (United States)

Yilmaz, Ihsan; Altan, Cigdem; Aygit, Ebru Demet; Alagoz, Cengiz; Baz, Okkes; Ahmet, Sibel; Urvasizoglu, Semih; Yasa, Dilek; Demirok, Ahmet

2014-01-01

WE AIMED TO COMPARE INTRAOCULAR PRESSURE (IOP) MEASUREMENTS VIA THREE DIFFERENT TONOMETERS: the Goldmann applanation tonometer (GAT), the Tono-Pen(®) XL (TPXL), and a non-contact airpuff tonometer (NCT). This was a cross-sectional study of 200 eyes from 200 patients. Right eyes of all patients were included in this study. IOP was measured via GAT, NCT, and TPXL by three physicians. Each physician used one of the tonometers. Measurements via the three devices were compared. The mean IOP was 15.5±2.2 mmHg (range 10-22) with the GAT, 16.1±3.0 (range 9-25) with the TPXL, and 16.1±2.8 (range 10-26) with the NCT. Bland-Altman analysis showed that the mean difference between measurements from the NCT and the GAT was 0.6±2.3 mmHg. The mean difference between the TPXL and GAT measurements was 0.7±2.5 mmHg. The mean difference between the NCT and TPXL measurements was -0.02±3.0 mmHg. There was no significant difference between the groups according to a one-way analysis of variance (ANOVA) test. P-values were 0.998 for NCT-TPXL, 0.067 for NCT-GAT, and 0.059 for TPXL-GAT. The NCT and TPXL provide IOP measurements comparable to those of the gold standard GAT in normotensive eyes.

[Comparison of tonometry with the Keeler air puff non-contact tonometer "Pulsair" and the Goldmann applanation tonometer].

Science.gov (United States)

Yücel, A A; Stürmer, J; Gloor, B

1990-10-01

Intraocular pressure (IOP) readings were performed with the Keeler Air-Puff Non-Contact Tonometer "Pulsair" in 126 patients before (NCT1) and after (NCT2) applanation-tonometry with the Goldmann device (GAT). For the whole population of 126 patients, in each of whom only one eye was selected, there was a significant difference of the mean IOP measurement, but the difference between the two measurement methods was only slightly significant when the NCT was applied before the GAT, and highly significant vice versa. Also the variation of the NCT-measurements was significantly larger than that for the GAT, while the before- and after GAT measurements had equal variations. If only the measurements under 18 mmHg mean GAT are taken into account (n = 101), the difference between GAT and NCT1 was not significant (p = 0.437), as opposed to the GAT-measurements above 18 mmHg, where a highly significant difference between the means was found (p = 0.0033). In most cases, the IOP-readings were underestimated using NCT. The Non Contact Tonometer "Pulsair" could be used for IOP-readings in patients with increased risk of infection, as well as in those with known allergic reactions to topical anesthetic agents, with poor or absent fixation ability, with corneal edema, and postoperative after anterior-segment surgery. The possibility of IOP-measurement in a reclined position is a true advantage of the Non-Contact Tonometer presented here. A measuring strategy for the above-mentioned applications is presented.

[The influence of corneal thickness and curvature on the difference between intraocular pressure measurements obtained with a non-contact tonometer and those with a Goldmann applanation tonometer].

Science.gov (United States)

Matsumoto, T; Makino, H; Uozato, H; Saishin, M; Miyamoto, S

2000-05-01

The influence of corneal thickness and curvature on the difference between intraocular pressure (IOP) measurements obtained with a non-contact tonometer (NCT) and those with a Goldmann applanation tonometer (GAT) was studied. The corneal thickness and curvature were obtained in 230 eyes of 115 subjects. The correlation between them and ratios of measurement with NCT to that with GAT ([NCT/GAT]) were examined. [NCT/GAT] and corneal thickness showed a significant positive correlation (r = 0.556, p < 0.01), but, the correlation between [NCT/GAT] and the radius of corneal curvature was not statistically significant (r = -0.035, p = 0.30). The thick cornea has more influence on the measurement with NCT than GAT, because IOP is measured with NCT over a wider applanation area. The corneas with steeper curvature also cause higher corneal rigidity and produce more overestimation of NCT measurement, while they have stronger capillary attraction of the precorneal tear film for the GAT tip and also produce overestimation of GAT measurement. As a result, [NCT/GAT] was believed to be not influenced by the corneal curvature.

The Influence of Corneal Thickness and Curvature on the Difference Between Intraocular Pressure Measurements Obtained with a Non-contact Tonometer and Those with a Goldmann Applanation Tonometer.

Science.gov (United States)

Matsumoto; Makino; Uozato; Saishin; Miyamoto

2000-11-01

Purpose: The influence of corneal thickness and curvature on the difference between intraocular pressure (IOP) measurements obtained with a non-contact tonometer (NCT) and those with a Goldmann applanation tonometer (GAT) was studied.Methods: The corneal thickness and curvature were obtained in 230 eyes of 115 subjects. The correlation between them and ratios of measurement with NCT to that with GAT ([NCT/GAT]) were examined.Results: [NCT/GAT] and corneal thickness showed a significant positive correlation (r = 0.556, P <.01), but, the correlation between [NCT/GAT] and the radius of corneal curvature was not statistically significant (r = -0.035, P =.30).Conclusion: The thick cornea has more influence on the measurement with NCT than GAT, because IOP is measured with NCT over a wider applanation area. The corneas with steeper curvature also cause higher corneal rigidity and produce more overestimation of NCT measurement, while they have stronger capillary attraction of the precorneal tear film for the GAT tip and also produce overestimation of GAT measurement. As a result, [NCT/GAT] was believed to be not influenced by the corneal curvature.

Clinical estimation of intraocular pressure with a non-contact tonometer and Goldman applanation tonometer as a tool for mass screening and its correlation with central corneal thickness: A comparative hospital based study

Directory of Open Access Journals (Sweden)

Anshulee Sood

2015-01-01

Full Text Available Purpose To assess the mean difference between intra-ocular pressure measurement by Goldmann applanation tonometer and Non Contact tonometer to determine the suitability of tonometer for community or mass screening and the variation in intra-ocular pressure between the two devices with respect to CCT. Material and Methods The proposed study was conducted on 300 eyes of 150 patients. The IOP assessment with the Goldmann applanation tonometer was always subsequent to that with the air-puff noncontact tonometer (AT-555. An average of three readings taken 15 seconds apart, with each method was taken to get final intraocular pressure reading for each eye. The central corneal thickness (CCT measurements were performed using the pachymeter. Results Majority of the eyes were found to be in the 12-24 mmHg group i.e. 51 % eyes in the right eye and 64 % in the left eye. 3. Mean IOP measured with NCT was 22.30±10.149 mmHg and with GAT was 18.31±7.427 mmHg, thus showing a difference of 3.99 mmHg. In patients where IOP was 24mm Hg the difference in the mean IOP for right eye was 5.69mmHg and for left eye 7.84mmHg (p<0.001. Both the methods of IOP measurement showed positive correlation with central corneal thickness. The NCT was more influenced by CCT than GAT; for every 10 micron CCT change, the IOP change expected with NCT was 0.47 mmHg and GAT was 0.29 mmHg. Conclusion Thus we can conclude that NCT can be used as a screening procedure in tertiary care centres catering to a large number of patients wherein it is not possible to do Goldmann applanation tonometry on all patients.. However, intraocular pressure readings may require adjustment, especially when measured with NCT in those patients who have a CCT that is significantly different from population mean.

Influence of corneal parameters in keratoconus on IOP readings obtained with different tonometers.

Science.gov (United States)

Firat, Penpe Gul; Orman, Gozde; Doganay, Selim; Demirel, Soner

2013-03-01

Accurate intraocular pressure (IOP) measurement is important but of unsure reliability in patients with keratoconus. Different types and models of tonometers are available. This study investigated the influence of corneal parameters on IOP readings obtained by a Goldmann applanation tonometer, a non-contact tonometer and a dynamic contour tonometer. IOP readings with the Goldmann applanation, non-contact and dynamic contour tonometers were obtained from 52 patients with keratoconus and from 50 normal subjects and their corneal parameters were measured using a Pentacam. The mean IOP measurements in keratoconus obtained with the Goldmann applanation, non-contact and dynamic contour tonometers were statistically significantly different from the mean IOP measurements in the normal subjects (p contact tonometers but not on the dynamic contour tonometer. In the control group, thinnest and central corneal thicknesses had a significant effect on findings with the Goldmann and non-contact tonometers but not on the dynamic contour tonometer. The corneal volume (CV) had no significant effect on the three tonometers in both groups. The corneal parameters affecting the IOP readings of the Goldmann applanation tonometers, non-contact tonometers and the dynamic contour tonometers are not the same. While the Goldmann applanation and non-contact tonometers were significantly affected by the corneal parameters that were measured, the dynamic contour tonometer was not affected by any of these corneal parameters. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

[Comparative study of intraocular pressure measurements by Goldmann applanation tonometer, noncontact tonometer and TonoPen].

Science.gov (United States)

Ceská, Burdová M; Ferrová, K; Filous, A; Oskorypová, K; Lezatková, P; Sedlácková, P

2012-02-01

The purpose of the study was to compare the levels of the intraocular pressure (NOT) measured in one eye at the same moment by three different methods: by Goldmann applanation tonometer (AT), non-contact tonometer (BT) and Tono-Pen (TP). It was further set the average variability of the performed measurements for particular tonometric methods. NOT was assessed in 106 eyes of 106 subjects aged 7-77 years (average 34.3 +/- 17.1 years). NOT was measured at the same moment with BT, TP and AT. The obtained data were statistically analyzed. The average NOT was 16.55 +/- 2.95, 17.95 +/- 4.47 and 16.13 +/- 3.4 mmHg when AT, BT and TP were applied. Average variability of three measurements for AT, BT and TP was 1.51 +/- 0.96, 1.78 +/- 1.08 and 1.47 +/- 0.9 mmHg. Average NOT levels of the measured AT and TP were almost identical with a difference of 0.42 mmHg (p = 0.236). Average level of the intraocular pressure measured by BT was higher by 1.40 mmHg and 1.82 mmHg in comparison with AT and TP (p = 0.00002), respectively. NOT measurement produced almost identical average levels at AT and TP, whereas at BT the levels were much higher. Average variability of the three subsequent NOT measurements was the highest at BT, whereas at AT and TP the average variability was lower and nearly identical.

CLINICAL-EVALUATION OF 2 NONCONTACT TONOMETERS

NARCIS (Netherlands)

KOOPMANS, SA; KOOIJMAN, AC; VANRIJ, G; EISSES, J; DEGROOTWOLTJER, J

1991-01-01

The precision and speed of two non-contact tonometers were examined and compared. The Goldmann applanation tonometer was used as the standard for precision. On the average the results obtained with the non-contact tonometers were not significantly different from those obtained with the Goldmann

The non-contact tonometer. Its value and limitations.

Science.gov (United States)

Shields, M B

1980-01-01

A review of the literature and a comparative study against Goldmann applanation tonometers suggest that the non-contact tonometer is reliable for measuring intraocular pressures within the normal range. In addition, the non-contact tonometer eliminates the need for corneal contact and topical anesthesia, thereby avoiding the potential problems of corneal abrasion, spread of infection, and drug reactions. The instrument can be used reliably by paramedical personnel and has particular value in mass screening and possibly in studies of topical antiglaucoma drugs. The non-contact tonometer is less reliable in patients with elevated intraocular pressure, since comparative studies against the Goldmann applanation tonometers have shown poorer correlations in the higher pressure ranges. The instrument is also limited by an abnormal cornea or poor fixation, which may interfere with accurate pressure measurements. Furthermore, the non-contact tonometer is less portable than many tonometers and more expensive than most.

Accuracy of the new ICare rebound tonometer vs. other portable tonometers in healthy eyes.

Science.gov (United States)

García-Resúa, Carlos; González-Meijome, José M; Gilino, Jorge; Yebra-Pimentel, Eva

2006-02-01

The ICare (Tiolat Oy, Helsinki, Finland) is a new portable tonometer that measures intraocular pressure (IOP) with a new rebound method, in which a very light probe is used to make momentary contact with the cornea in slow motion. The purpose of this study is to assess the accuracy of the ICare IOP measurements by comparing them against other portable tonometers: Perkins applanation tonometer and Tono-Pen XL digital tonometer (Medtronic Solan, Jacksonville, FL). Sixty-five young subjects were assessed with each of the tonometers. ICare tonometry was performed first, followed by Perkins applanation tonometry and Tono-Pen XL in a random order. Regression analysis was used to evaluate the relationship between the Perkins tonometer and the remaining tonometers used in this study. Tonometers were also compared by plotting the difference between the methods against the mean. The hypothesis of zero bias was examined by a paired t test and the 95% limits of agreement (LoA) were calculated. ICare and Tono-Pen XL significantly overestimate IOP when compared with Perkins applanation tonometry. The mean of the difference between Perkins and ICare and Perkins and Tono-Pen XL was (mean +/- standard deviation) -3.35 +/- 2.28 mm Hg and -2.78 +/- 2.53 mm Hg, respectively. The 95% LoA between Perkins tonometry and ICare tonometry were between -7.81 and +1.12 and between Perkins tonometry and Tono-Pen XL tonometry between -7.74 and +2.18. Compared with Perkins tonometry, the ICare tonometer allows clinicians to estimate IOP with a portable, rapid, and noninvasive method with similar reliability to that offered by Tono-Pen XL. Clinicians should be aware of the systematic overestimation of IOP with the ICare. Further research is needed to evaluate the performance of rebound tonometry in populations with higher IOP and assess the reliability of this technique in the early detection and follow up of glaucomatous patients.

Reliability of the Nidek NT-1000 non contact tonometer.

Science.gov (United States)

Van de Velde, T; Zeyen, T

1995-01-01

In this prospective study, we compared the intraocular pressure (IOP) readings of 100 patients measured with the Goldmann applanation tonometer and the Nidek NT-1000 pneumotonometer. The correlation coefficient between the Goldmann and Nidek readings was 0.86. On the average the pneumotonometer overestimated the intraocular pressure with 0.43 mm Hg. The Nidek NT-1000 non contact tonometer can be used for screening purposes provided an appropriately low IOP value is used to indicate the need for further assessment with the Goldman applanation tonometer.

Nonoptical definition of applanation surface.

Science.gov (United States)

Draeger, J; Rumberger, E; Hechler, B; Wirt, H; Levedag, S; Rudolph, G; Ludwig, B; Klemm, M

1987-01-01

Based on the Imbert-Fick law and the theoretical considerations of Goldmann, new applanation tonometers were designed, still using an applanation diameter of 3.06 mm to avoid a new biometric calibration. Three different electronic recording devices were used for the area assessment. An optical, a capacitance and a digital line sensor were tested in first calibration experiments.

CORRELATION OF INTRAOCULAR PRESSURE MEASUREMENTS WITH NON CONTACT TONOMETER AND GOLDMANN APPLANATION TONOMETRY

Directory of Open Access Journals (Sweden)

Leya Sara George

2017-07-01

Full Text Available BACKGROUND A complete ophthalmologic examination includes intraocular pressure (IOP measurement, which is a routine procedure and is important for diagnosis and monitoring of glaucoma. IOP measurement is most commonly done using Goldmann Applanation tonometer and Non-Contact tonometer. MATERIALS AND METHODS In this study IOP measurements of 500 eyes (glaucomatous and non-glaucomatous were performed using GAT and NCT on patients visiting the outpatient clinic of Department of Ophthalmology at Christian Medical College and Hospital, Ludhiana. This was a cross sectional and observational study. Comparison of IOP values was done in different IOP ranges. CCT was measured and analysis of its correlation with GAT and NCT was done. RESULTS Both methods of tonometry correlated significantly in patients with IOP <24 mm Hg. The mean IOP measured by NCT, was 16.06 ± 5.85 mm Hg and the mean IOP measurement by GAT was 16.61 ± 6.94 mm Hg. Intraocular pressure readings with GAT and NCT positively correlated with CCT. CONCLUSION NCT may be useful for screening in clinical settings but borderline high IOP readings should be confirmed with GAT. Our findings, also suggest that CCT is an essential variable to consider in interpreting IOP readings.

Comparison of intraocular pressure as measured by three different non-contact tonometers and goldmann applanation tonometer for non-glaucomatous subjects.

Science.gov (United States)

Bang, Seung Pil; Lee, Chong Eun; Kim, Yu Cheol

2017-11-02

To compare the measurement of intraocular pressure (IOP) among the three different non-contact tonometers (NCT) and the Goldmann applanation tonometer (GAT) for non-glaucomatous subjects. In 52 eyes of 52 non-glaucomatous subjects, IOP was measured sequentially with the Canon TX-20P, the Nidek NT-530P, the Topcon CT-1P, and the GAT at the same time. We evaluated the IOP-measurement agreement among the tonometers as well as the factors affecting the measurements. A significant positive correlation was shown between the IOP values obtained with GAT and each NCT. The Canon TX-20P showed statistically the most significant agreement with the GAT (ICC 0.906, 95% CI 0.837-0.946). In an analysis of the Bland-Altman plots, the Canon TX-20P also showed the largest mean bias (1.38 mmHg) but the narrowest limits of agreement (LoA) (95% LoA; ± 3.43 mmHg). The Topcon CT-1P showed the smallest mean bias (0.48 mmHg) but the widest LoA (95% LoA; ± 4.16 mmHg). The Topcon CT-1P and Nidek NT-530P both showed a significantly positive correlation between increasing central corneal thickness (CCT) and increasing IOP. There was a statistically significant correlation between each of the three different NCT and the GAT measurements. IOP measured with the Canon TX-20P and Topcon CT-1P tended to be higher, and with the Nidek NT-530P lower, than with the GAT. Practitioners need to know the properties of their own NCTs and their respective measurement tendencies.

Comparison of intraocular pressure measurement between rebound, non-contact and Goldmann applanation tonometry in treated glaucoma patients.

Science.gov (United States)

Vincent, Stephen J; Vincent, Roslyn A; Shields, David; Lee, Graham A

2012-01-01

To compare the intraocular pressure readings obtained with the iCare rebound tonometer and the 7CR non-contact tonometer with those measured by Goldmann applanation tonometry in treated glaucoma patients. A prospective, cross-sectional study was conducted in a private tertiary glaucoma clinic. One hundred nine (54 males : 55 females) patients including only eyes under medical treatment for glaucoma. Measurement by Goldmann applanation tonometry, iCare rebound tonometry and 7CR non-contact tonometry. Intraocular pressure. There were strong correlations between the intraocular pressure measurements obtained with Goldmann and both the rebound and non-contact tonometers (Spearman r-values ≥ 0.79, P tonometer. For the rebound tonometer, the mean intraocular pressure was slightly higher compared with the Goldmann applanation tonometer in the right eyes (P = 0.02), and similar in the left eyes (P = 0.93); however, these differences did not reach statistical significance. The Goldmann correlated measurements from the non-contact tonometer were lower than the average Goldmann reading for both right (P 0.01) eyes. The corneal compensated measurements from the non-contact tonometer were significantly higher compared with the other tonometers (P ≤ 0.001). The iCare rebound tonometer and the 7CR non-contact tonometer measure intraocular pressure in fundamentally different ways to the Goldmann applanation tonometer. The resulting intraocular pressure values vary between the instruments and will need to be considered when comparing clinical versus home acquired measurements. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

Effects of puff times on intraocular pressure agreement between non-contact and Goldmann applanation tonometers

Directory of Open Access Journals (Sweden)

Ibrahim Toprak

2014-07-01

Full Text Available AIM: To compare intraocular pressure(IOPvalues obtained from two different puff modes of Canon TX-F non-contact tonometer(NCTand Goldmann applanation tonometer(GATin patients with primary open angle glaucoma(POAG. METHODS: The study group comprised 55 right eyes of 55 patients with a confirmed diagnosis of POAG, which were under treatment. All patients underwent detailed ophthalmological examinations, optical coherence tomography imaging and automated perimetry. Intraocular pressure measurements were performed using 1-puff mode of NCT(NCT1, 3-puffs mode of NCT(NCT3and GAT with 5 minutes intervals in order. RESULTS: Fifty-five eyes of 55 patients with POAG(mean age of 64.1±8.1 yearswere enrolled into the study. NCT1 and NCT3 gave similar IOP values when compared with GAT measurements(14.22±3.42, 14.28±3.29, 14.66±3.49mmHg respectively, P=0.291. Intertonometer agreement was assessed using the Bland-Altman method. The 95% limits of agreement(LoAfor NCT1-GAT, NCT3-GAT and NCT1-NCT3 comparisons were -4.9 to +4.4mmHg, -4.1 to +3.4mmHg, and -3.4 to +3.3mmHg respectively.CONCLUSION: Although IOP measurements obtained from two puff modes of NCT and GAT showed similar values, wide range of LoA might restrict use of NCT1, NCT3 and GAT interchangeably in POAG patients.

Clinical performance of the Reichert AT550: a new non-contact tonometer.

Science.gov (United States)

Jorge, J; Díaz-Rey, J A; González-Méijome, J M; Almeida, J B; Parafita, M A

2002-11-01

The aim of the present study was to assess the level of accuracy for measurements of intra-ocular pressure (IOP) obtained with a new non-contact tonometer (NCT) the Reichert AT550. Measurements were compared against those obtained with the Reichert Xpert Plus, Goldmann applanation tonometer and Perkins tonometer. Thirty-five university students were assessed with the four tonometers in a randomised order, with non-contact tonometry performed first. Each of the four measurement devices had its own trained clinical observer. Plots of differences of IOP as a function of the mean for each pair of instruments were obtained. No statistically significant differences were found when comparing the AT550 NCT with contact applanation tonometry (AT) (p> 0.05), displaying the closest level of agreement (as represented by the lowest mean difference and the narrowest confidence interval) with the Goldmann tonometer (limits of agreement, 0.12+/-2.17). In conclusion, readings of IOP with the AT550 NCT are clinically comparable with those obtained with Goldmann tonometry in a population with IOP within the normal range.

Corneal epithelial alterations resulting from use of chlorine-disinfected contact tonometer after myopic photorefractive keratectomy.

Science.gov (United States)

Maldonado, M J

1998-08-01

This study aimed to describe a previously unreported complication associated with the use of chlorine-disinfected applanation tonometer heads for intraocular pressure measurement after excimer laser photorefractive keratectomy. Two retrospective case reports. Two patients underwent, respectively, a 7-diopter and a 4-diopter myopic excimer laser correction in their first eye 2 weeks apart. Complete epithelial closure of the ablated area was observed by biomicroscopy in the first-week examination. Four weeks after photorefractive keratectomy, a complete ophthalmic examination was performed. Goldmann applanation tonometry was performed bilaterally after thoroughly rinsing and drying the tonometer biprism, which had been immersed regularly in a chlorine 5000-parts per million solution. Slit-lamp examination and corneal topographic surface regularity were measured. A few minutes after applanation tonometry, both patients reported ocular discomfort in the excimer laser-treated eyes, whereas the untreated fellow eyes were painless. Punctate corneal lesions and superficial epithelial cell clumping were present in the first patient's treated eye, predominantly in the inferior aspect of the applanated cornea. Visual inspection showed a normal tonometer tip. In the second patient's treated cornea, a focal epithelial defect was identified biomicroscopically, which corresponded to the steeper region within the ablation zone on the videokeratograph. In this case, crystal deposits were found on the tonometer tip. The epithelial alterations resolved without sequelae in both cases. Disinfecting solutions of chlorine can cause crystal deposit formation on the tonometer head. Applanation tonometry after repeated disinfection with chlorine solutions appears to have the potential for disrupting the epithelial layer of the healing cornea. Covered contact tonometry or noncontact tonometry should be evaluated as alternative methods to chemically disinfected contact tonometry for

[Effects of central corneal thickness and corneal curvature on measurement of intraocular pressure with Goldmann applanation tonometer and non-contact tonometer].

Science.gov (United States)

Zhang, Yang; Zhao, Jia-liang; Bian, Ai-ling; Liu, Xiao-li; Jin, Yu-mei

2009-08-01

To investigate the effects of central corneal thickness (CCT) and corneal curvature (CC) on intraocular pressure (IOP) measurements by the Goldmann applanation tonometer (GAT) and the non-contact tonometer (NCT). One hundred and twenty patients were recruited from the clinic of Peking Union Medical College Hospital. The CCT was measured by ultrasound pachymetry and the mean radius of CC by using Canon PK-5 refractometer. The IOP of each eye was measured by both GAT and NCT. Linear regression was used to compare the measurements of GAT and NCT; multi regression was used to analyze the relationships between CCT, CC and the measurements of GAT and NCT. Bland-Altman method was used to compare the effect of NCT and GAT on the IOP measurements. The results of the right eyes were reported in this paper. The mean and standard deviation of IOP measured by GAT and NCT was (18.4 + or - 4.0) mm Hg (1 mm Hg = 0.133 kPa) and (17.0 + or - 4.6) mm Hg, respectively, the difference was statistically significant (r = 0.835, P = 0.000). IOP measured using GAT increased by 0.039 mm Hg per microm increase in CCT. IOP measured using NCT increased by 0.064 mm Hg per microm increase in CCT. For an increase of 1 mm of mean corneal curvature there was decrease in IOP of 2.648 mm Hg measured by the GAT and of 3.190 mm Hg measured by the NCT. Compared to the GAT, NCT underestimated at low IOP level and overestimated at higher IOP level. The IOP measurement obtained with both GAT and NCT varied with CCT and CC. CCT affected IOP measurements by NCT more than that by GAT.

[Principle and results of a new "non-contact-tonometer" are discussed (author's transl)].

Science.gov (United States)

Draeger, J; Jessen, K; Haselmann, G

1975-07-01

Comparing measurements with Non-Contact-Tonometer and handapplanation tonometer on 462 eyes with normal and elevated intraocular tension are statistically evaluated. The 2-s-limits for normal i.o. pressure at +/- 6.52 mm Hg (+/- 8.6 mbar), for elevated intraocular pressure +/- 13.2 mm Hg (+/- 17.6 mbar). This means less reliability than conventional applanation tonometers or even Schiötz-tonometers. The unability to read the tension when the corneal surface is rough means remarkable disadvantages to clinical use.

Simulation of non-contact tonometer - Ocular response analyzer

Directory of Open Access Journals (Sweden)

M. Arsalan Khan

2016-04-01

Simultaneous explosion of ophthalmic knowledge and medical instrument, being made in the 19th century, has led to the invention of tonometers of varied designs and principles, and Non-Contact Tonometers (NCTs are among them. Glodmann Applanation Tonometer (GAT is considered the ‘gold standard’ in measuring IOP; however, IOP measurement using GAT is now known to be affected by various factors like corneal thickness, curvature and material properties as demonstrated by Khan [1]. Due to inaccuracies in measuring IOP by GAT, this ‘gold standard’ has been challenged. Therefore, the present research aims to develop a multi-parametric correction equation to determine the True Intraocular Pressure (IOPT using Non-Contact Tonometer and the current article focuses on evaluating the influence of individual parameters on IOP by NCT.

Incidence of open-angle glaucoma and screening of the intraocular pressure with a non-contact tonometer.

Science.gov (United States)

Rouhiainen, H; Teräsvirta, M

1990-06-01

New equipment for measuring intraocular pressure have been introduced lately. One of these is the Keeler Pulsair non-contact tonometer which uses pressurized air in measurement. It is found to be safe and easy to use in practice, but it seems to give 1.5-2.0 mmHg lower reading than the Goldmann applanation tonometer. This was confirmed by the present study, where non-contact tonometry was controlled by applanation tonometry with a 2-3 week delay between the measurements. However, for screening procedures the accuracy of the apparatus can be considered as sufficient.

21 CFR 886.1930 - Tonometer and accessories.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tonometer and accessories. 886.1930 Section 886.1930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... type) or to measure intraocular tension by applanation (applying a small flat disk to the cornea...

Comparison of intraocular pressure measured by non-contact air puff versus Goldmann applanation tonometers in gas-filled vitrectomized eyes.

Science.gov (United States)

Patikulsila, Direk; Taweemankongsab, Srisuda; Ngamtipakorn, Supob

2003-05-01

To compare intraocular pressure (IOP) measured by two different instruments, air puff tonometer (APT) versus Goldmann applanation tonometer (GAT), in gas-filled vitrectomized eyes. Three-month, prospective, comparative trial. Thirty-eight patients (38 eyes), who underwent a pars plana vitrectomy (PPV) with gas injection, were enrolled in the study. The IOP was measured by an APT, followed by GAT within 10 minutes by two different, masked investigators. IOPs were measured by two methods and then were compared. Overall, there was a high correlation between both measurements (r = 0.908, p 0.05). By a subgroup analysis of 17 eyes with IOP measured by a GAT of 21 mmHg or less, the APT readings (15.28 +/- 4.81) and GAT readings (14.47 +/- 3.89) were not significantly different (p > 0.05). Of 21 eyes, with IOP measured by a GAT of 22 mmHg or more, the APT readings (26.88 +/- 8.81) were significantly lower than those obtained by the GAT (29.62 +/- 7.69) (p < 0.05). In gas-filled vitrectomized eyes, IOP measurements obtained by an APT correlated well with those obtained by GAT, especially when the IOP was within normal range. However, in eyes with elevated IOP, the APT significantly underestimated the IOP measurement when compared to the gold standard, GAT.

Does the surface property of a disposable applanation tonometer account for its underestimation of intraocular pressure when compared with the Goldmann tonometer?

Science.gov (United States)

Osborne, Sarah F; Williams, Rachel; Batterbury, Mark; Wong, David

2007-04-01

Disposable tonometers are increasingly being adopted partly because of concerns over the transmission of variant Creutzfeldt-Jakob disease and partly for convenience. Recently, we have found one such tonometer (Tonojet by Luneau Ophthalmologie, France) underestimated the intraocular pressure (IOP). We hypothesized that this underestimation was caused by a difference in the surface property of the tonometers. A tensiometer was used to measure the suction force resulting from interfacial tension between a solution of lignocaine and fluorescein and the tonometers. The results showed that the suction force was significantly greater for the Goldmann compared to the Tonojet. The magnitude of this force was too small to account for the difference in IOP measurements. The Tonojet was less hydrophilic than the Goldmann, and the contact angle of the fluid was therefore greater. For a given tear film, less hydrophilic tonometers will tend to have thicker mires, and this may lead to underestimation of the IOP. When such disposable tonometers are used, it is recommended care should be taken to reject readings from thick mires.

A comparison of intraocular pressure values obtained with the Tono-Pachymeter NT530P, iCare® rebound tonometer and Goldmann applanation tonometer

Directory of Open Access Journals (Sweden)

N. Rampersad

2011-12-01

Full Text Available The purpose of this study was to compare the intraocular pressure (IOP values measured with the Tono-Pachymeter NT530P (Tonopachy™ and the iCare® rebound tonometer (iCare® with those obtained by the Goldmann applanation tonometer (GAT. The right eyes of 105 subjects aged 18 to 82 years (mean age = 29.27 ± 14.67 years were assessed with the three tonometers. Central corneal thickness (CCT was measured first using the Tonopachy™ and then IOP was measured by Tonopachy™, iCare® and GAT. The data was analyzed with descriptive statistics, paired  t-test, correlation and regression analysis. The Bland-Altman method of analysis was used to evaluate agreements between the sets of data from the three devices. The CCT values ranged from 440 µm to 606 µm (mean= 518.49 ± 33.01 µm. There was little or no correlation between CCT and IOP for any of the instruments used in this study (r = 0.29 for Tonopachy™, r = 0.22 for iCare®, r = 0.17 for GAT. The mean IOP measured with the Tonopachy™ was 14.31 ± 3.57 mmHg (range 8.7 mmHg to 31 mmHg and 16.64 ± 4.38 mmHg (range 8 mmHg to 32 mmHg using the iCare®. The mean IOP measured with the GAT was 14.79 ± 3.09 mmHg (range 8.7 mmHg to 29.7 mmHg. Using the Bland-Altman method, the upper and lower limits of agreement between the Tonopachy™ and GAT, iCare® and GAT, iCare® and Tonopachy™ were 5.1 mmHg and –4.2 mmHg, 8.6 mmHg and –4.9 mmHg, 7.5 mmHg and –2.8 mmHg respectively. In 79.1% of the eyes studied, the mean IOP difference between Tonopachy™ and GAT was less than 3 mmHg and in 20.9% of the eyes, the difference was greater than 3 mmHg. However, mean IOP differences of greater than 3 mmHg were obtained by iCare® in comparison with GAT (40% and Tonopachy™ (34.3% respectively. Findings of this study suggest that the Tonopachy™ yielded IOP readings that were consistent with those of GAT values while iCare® yielded higher IOP values compared to both GAT and Tonopachy™. (S Afr

Goldmann tonometry tear film error and partial correction with a shaped applanation surface

Directory of Open Access Journals (Sweden)

McCafferty SJ

2018-01-01

Full Text Available Sean J McCafferty,1–4 Eniko T Enikov,5 Jim Schwiegerling,2,3 Sean M Ashley1,3 1Intuor Technologies, 2Department of Ophthalmology, University of Arizona College of Medicine, 3University of Arizona College of Optical Science, 4Arizona Eye Consultants, 5Department of Mechanical and Aerospace, University of Arizona College of Engineering, Tucson, AZ, USA Purpose: The aim of the study was to quantify the isolated tear film adhesion error in a Goldmann applanation tonometer (GAT prism and in a correcting applanation tonometry surface (CATS prism.Methods: The separation force of a tonometer prism adhered by a tear film to a simulated cornea was measured to quantify an isolated tear film adhesion force. Acrylic hemispheres (7.8 mm radius used as corneas were lathed over the apical 3.06 mm diameter to simulate full applanation contact with the prism surface for both GAT and CATS prisms. Tear film separation measurements were completed with both an artificial tear and fluorescein solutions as a fluid bridge. The applanation mire thicknesses were measured and correlated with the tear film separation measurements. Human cadaver eyes were used to validate simulated cornea tear film separation measurement differences between the GAT and CATS prisms.Results: The CATS prism tear film adhesion error (2.74±0.21 mmHg was significantly less than the GAT prism (4.57±0.18 mmHg, p<0.001. Tear film adhesion error was independent of applanation mire thickness (R2=0.09, p=0.04. Fluorescein produces more tear film error than artificial tears (+0.51±0.04 mmHg; p<0.001. Cadaver eye validation indicated the CATS prism’s tear film adhesion error (1.40±0.51 mmHg was significantly less than that of the GAT prism (3.30±0.38 mmHg; p=0.002.Conclusion: Measured GAT tear film adhesion error is more than previously predicted. A CATS prism significantly reduced tear film adhesion error by ~41%. Fluorescein solution increases the tear film adhesion compared to

Clinical evaluation of the new TGDc-01 "PRA" palpebral tonometer: comparison with contact and non-contact tonometry.

Science.gov (United States)

García Resúa, Carlos; Giráldez Fernández, Maria J; Cerviño Expósito, Alejandro; González Pérez, Javier; Yebra-Pimentel, Eva

2005-02-01

The TGDc-01 "PRA" (Ryazan State Instrument, Ryazan, Russia) tonometer is a new portable small-sized tonometer that measures intraocular pressure (IOP) through the eyelid. The purpose of this study is to assess the repeatability of the TGDc-01 IOP measurements by comparing them against those obtained with Goldmann tonometer and with those from Perkins applanation tonometer, Xpert (Reichert, Depew, NY) noncontact tonometer, and Tono-Pen XL (Medtronic Solan, Jacksonville, FL) digital tonometer. Fifty-eight right eyes of 58 young subjects were measured with each of the tonometers. Noncontact tonometry was performed first, followed by Goldmann and Perkins applanation tonometer (in random order), digital Tono-Pen XL, and finally TGDc-01 tonometer (sitting and supine position). Correlation analysis was used to evaluate the relationship between the Goldmann tonometer and the remaining tonometers used in this study. Plotting the difference between the methods against mean was also done to compare the tonometers. The hypothesis of zero bias was examined by a paired t-test. The 95% limits of agreement (LoA) were also calculated. TGDc-01 showed no statistical difference between the IOP measurements obtained in sitting and supine positions. A poor relationship between the TGDc-01 and Goldmann tonometer was found (r = 0.173; p = 0.001). Although the mean differences between Goldmann and Tonopen XL, Xpert, and TGDc-01 IOP measurements were statistically significant, the wider 95% LoA was observed when comparing the Goldmann and TGDc-01 tonometers. Computation of the 95% LoA resulted in a wide bias range when comparing the TGDc-01 with all the tonometers used in this study. The TGDc-01 "PRA" tonometer was not comparable with the other techniques used in the study. The wide dispersion range of the values obtained shows low repeatability of the TGDc-01 for screening purposes. These results could be because of the technique of measurement and/or interindividual variables.

[Tonometry with a new non-contact tonometer].

Science.gov (United States)

Langmann, G; Schuhmann, G; Langmann, A; Zenz, H

1990-11-01

We conducted comparative measurements with 100 healthy probands and patients suffering of glaucoma with both a Goldmann Applanation Tonometer (GAT) and the new Keeler Non Contact Tonometer (NCT). A noticeable conformity of mean values in the group I with values under 23 mm Hg and in group II with values greater or equal 23 mm Hg was obvious. The results of three NCT measurement values were compared with those of four measurements. The Keeler NCT nearly fulfills the needed criteria for the first group with pressure under 23 mm Hg except for a high standard deviation. In group II (pressure greater or equal 23 mm Hg) the demanded nominal values are exceeded.

The influence of central corneal thickness and age on intraocular pressure measured by pneumotonometry, non-contact tonometry, the Tono-Pen XL, and Goldmann applanation tonometry

OpenAIRE

Tonnu, P-A; Ho, T; Newson, T; El Sheikh, A; Sharma, K; White, E; Bunce, C; Garway-Heath, D

2005-01-01

Aims: To evaluate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements made with the Goldmann applanation tonometer (GAT), Tono-Pen XL, ocular blood flow tonograph (OBF), and Canon TX-10 non-contact tonometer (NCT).

Aligning the Goldmann tonometer tip by means of the "precontact whitish rings".

Science.gov (United States)

Blumenthal, E Z

1999-01-01

A set of whitish rings observed before contact is made during Goldmann-type applanation tonometry can help simplify and speed the examination. The orientation and size of the rings are useful both in aligning the tonometer and in estimating the distance remaining before contact is made. Relying on these whitish rings can also avoid some of the shear-related damage exerted on the corneal epithelium from alignment movements of the tonometer tip after contact with the cornea has been made.

[A comparison of rebound tonometry (ICare) with TonoPenXL and Goldmann applanation tonometry].

Science.gov (United States)

Schreiber, W; Vorwerk, C K; Langenbucher, A; Behrens-Baumann, W; Viestenz, A

2007-04-01

Goldmann applanation tonometry and dynamic contour tonometry (PASCAL) are two well established slit lamp mounted tonometric methods. Intraocular pressure measurement in bedridden patients and children is often only possible using hand held tonometers (TonoPenXL, Perkins tonometer, Draeger tonometer). This study was performed to evaluate the hand held ICare tonometer, which is based on the rebound method. A total of 102 eyes were examined by two highly experienced ophthalmologists for: 1) ophthalmological status, 2) central corneal power (Zeiss IOL-Master), 3) central corneal thickness (Tomey ultrasound pachymetry, five successive measurements, SDr=0.592-0.642; p<0.001). There was a great intra-individual variability of up to 17 mmHg between the GAT, TonoPenXL and ICare methods. The ICare tonometer is easy to handle and high reliability. The data are comparable with those from the Goldmann tonometer. A tonography effect of 0.6 mmHg in the successive measurement series was found.

[Clinical evaluation of the dynamic rebound tonometer Icare].

Science.gov (United States)

Detry-Morel, M; Jamart, J; Detry, M B; Pourjavan, S; Charlier, L; Dethinne, B; Huge, L; Ledoux, A

2006-12-01

The Icare dynamic tonometer (impact or Rebound tonometry) is a new tonometer based on making a moving object collide with an eye and on monitoring the motion parameters of this object following contact. The purpose of this study was to assess intra- and interobserver variability of IOP measurements with the Icare and their correlations with Goldmann applanation tonometry (GAT) and central corneal thickness (CCT). A prospective study including three groups of patients: group 1 (50 normal subjects), group 2 (50 patients with OHT or POAG and GAT IOP>22 mmHg), and group 3 (38 glaucomatous patients with GAT IOPtonometer can be used as a screening device for ocular hypertension as long as CCT measurements can be taken.

Deterioration in the accuracy of the pulsair non-contact tonometer with use: need for regular calibration.

Science.gov (United States)

Atkinson, P L; Wishart, P K; James, J N; Vernon, S A; Reid, F

1992-01-01

The Pulsair non-contact tonometer (Keeler Pulsair: Keeler UK) has been shown to be a versatile instrument particularly suitable for screening for raised intraocular pressure. Although demonstrated to be accurate initially when compared to the Goldmann applanation tonometer no study has examined its long-term accuracy. Comparisons of three Pulsair tonometers with different degrees of usage with the Goldmann tonometer are described. Measurements were obtained from 64, 116, and 223 eyes in three separate comparative studies. Correlation coefficients of between 0.78 and 0.90 were obtained, the least used instrument being significantly more accurate than the two more extensively used instruments. Taking the Goldmann tonometer as the standard tonometer, and the aim to detect intraocular pressures of greater than 21 mmHg, sensitivities of 40%, 48%, and 85% for the three Pulsair tonometers respectively were shown. The Pulsair tonometer appears liable to a long-term drift in accuracy with use, and we suggest that provision is made for the regular re-calibration of the instrument.

Goldmann tonometry tear film error and partial correction with a shaped applanation surface.

Science.gov (United States)

McCafferty, Sean J; Enikov, Eniko T; Schwiegerling, Jim; Ashley, Sean M

2018-01-01

The aim of the study was to quantify the isolated tear film adhesion error in a Goldmann applanation tonometer (GAT) prism and in a correcting applanation tonometry surface (CATS) prism. The separation force of a tonometer prism adhered by a tear film to a simulated cornea was measured to quantify an isolated tear film adhesion force. Acrylic hemispheres (7.8 mm radius) used as corneas were lathed over the apical 3.06 mm diameter to simulate full applanation contact with the prism surface for both GAT and CATS prisms. Tear film separation measurements were completed with both an artificial tear and fluorescein solutions as a fluid bridge. The applanation mire thicknesses were measured and correlated with the tear film separation measurements. Human cadaver eyes were used to validate simulated cornea tear film separation measurement differences between the GAT and CATS prisms. The CATS prism tear film adhesion error (2.74±0.21 mmHg) was significantly less than the GAT prism (4.57±0.18 mmHg, p film adhesion error was independent of applanation mire thickness ( R 2 =0.09, p =0.04). Fluorescein produces more tear film error than artificial tears (+0.51±0.04 mmHg; p film adhesion error (1.40±0.51 mmHg) was significantly less than that of the GAT prism (3.30±0.38 mmHg; p =0.002). Measured GAT tear film adhesion error is more than previously predicted. A CATS prism significantly reduced tear film adhesion error bŷ41%. Fluorescein solution increases the tear film adhesion compared to artificial tears, while mire thickness has a negligible effect.

[Current status of the standardization of air impulse tonometers and their evaluation--as an example: the Non-Contact Tonometer II].

Science.gov (United States)

Jessen, K; Hoffmann, F

1983-10-01

The standard values and tolerances used in the assessment of the clinical efficiency of different types of tonometers are once again demonstrated. Investigations carried out in accordance with the existing test plan for comparative clinical measurements using two non-contact tonometers II (NCT II) and a calibrated applanation tonometer as a reference instrument in 155 patient eyes showed that both the regression equation and the scattering of the individual values around the regression curve satisfy the conditions of clinical assessment criteria. Of the individual values, 2.6% are outside the 95% limits. Following a brief illustration of the measuring principle of the NCT II, a test procedure is described for this type of tonometer. It consists of a torsion balance mounted on a cross-sliding carriage with a small mirror 2.5 mm in diameter and a control balance. A lens equipped with a centering cross is used for adjustment to the nominal distances of 11 mm between the nozzle and the cornea. This test procedure makes it possible to determine whether the digital display of any particular NTC II deviates from the nominal value by not more than +/- 1 digit in the range between "12" and "30" and by not more than +/- 2 digits between "31" and "50".

Clinical evaluation of the dynamic observing tonometer.

Science.gov (United States)

Morgan, Andrew J; Hosking, Sarah L; Salmon, John F

2002-08-01

The Dynamic Observing Tonometer (SmartLens, Ophthalmic Development Company AG, Zürich, Switzerland) is a diagnostic contact lens that allows continuous measurement of intraocular pressure, in addition to providing the investigator with a view of the posterior pole and anterior chamber angle. The purpose of this study was to determine the accuracy of this tonometer and the repeatability of the intraocular pressure measurements. The intraocular pressure was measured by Goldmann applanation tonometry in one randomly chosen eye of 40 subjects (median age 66 years, range 21-77 years). The intraocular pressure, pulse amplitude and 10-second continuous tonometric recordings were then taken using the Dynamic Observing Tonometer and a pneumatonometer. Accuracy was determined by calculating the mean bias and 95% limits of agreement of measurements made with the Dynamic Observing Tonometer against measurements made with the Goldmann and pneumatonometer. Repeatability was evaluated by calculating the differences between pairs of repeated measurements against the mean value and by calculating reliability coefficients. Intraocular pressure measurements made with the Dynamic Observing Tonometer had a mean bias of +2.1 mm Hg (95% limits of agreement: -4.0 to +8.2 mm Hg) compared with Goldmann tonometry. There was a reasonable correlation between Goldmann and Dynamic Observing Tonometer intraocular pressure readings (r = 0.78, P Tonometer was found to have a mean bias of +0.4 mm Hg (95% limits of agreement: -1.6 to +2.3 mm Hg) compared with the pneumatonometer (r = 0.78, P Tonometer reading was on average 0.4 mm Hg higher than the second (95% limits of agreement: -3.8 to +4.6 mm Hg) with a coefficient of reliability of 0.91. For pulse amplitude readings, the first reading was on average 0.1 mm Hg lower than the second (95% limits of agreement: -1.4 to +1.2 mm Hg) with a coefficient of reliability of 0.90. Intraocular pressure measurements taken with the Dynamic Observing Tonometer

Dynamic contour tonometry: presentation of a new tonometer.

Science.gov (United States)

Kanngiesser, Hartmut E; Kniestedt, Christoph; Robert, Yves C A

2005-10-01

With tonometers currently in use intraocular pressure is indirectly determined by measuring a physical quantity related to a specified deformation of the cornea. We present a new principle of direct, continuous, and transcorneal intraocular pressure measurement, describe its theoretical foundation, and evaluate its application on the basis of an in vitro model. On a living human eye an optimized pressure-sensitive contact surface was determined by performing pressure measurements with differently shaped tonometer heads. Based on these results and on the theoretical model, a Dynamic Contour Tonometer was constructed and validated on eye bank bulbi against a manometric reference pressure. A concave contact surface with a radius of curvature of 10.5 mm creates a distribution of forces between the central contour matching area of the tip and the cornea that equals the forces generated by the internal pressure of the eye. A sensor integrated into the surface having the same contour measures the intraocular pressure closely to the manometric reference pressure in human cadaver eyes. The accuracy of the tonometer appears to be unaffected by variations in corneal properties. Dynamic Contour Tonometry eliminates most of the systematic errors arising from individual changes of corneal properties that adversely influence all types of applanation tonometers. The advantage of measuring the true pressure in combination with the capability of registering dynamic pressure fluctuations discloses new tonometric opportunities to diagnose and classify different types of glaucoma.

Comparison of intraocular pressure measurements with different contact tonometers in young healthy persons

Directory of Open Access Journals (Sweden)

Saulius Galgauskas

2016-01-01

Full Text Available AIM: To analyze the correlation of Goldmann applanation tonometer (GAT, I-Care tonometer and Tono-Pen tonometer results in young healthy persons, and to investigate the influence of central corneal thickness (CCT on intraocular pressure (IOP measurements recorded with these tonometers. METHODS: We conducted a pilot clinical study in 78 eyes of 78 subjects aged 22-28 years old (44 women and 34 men; mean age 23.8±1.19y. IOP was measured using GAT, I-Care and Tono-Pen tonometers, followed by measurements of CCT. Statistical analysis was performed using SPSS 20.0. RESULTS: The mean IOPs and standard deviation (±SD for GAT, I-Care and Tono-Pen were 15.62±2.281 mm Hg, 16.29±2.726 mm Hg and 16.32±2.393 mm Hg, respectively. The mean CCT was 555.15±29.648 μm. Clear positive correlations between GAT and I-Care, GAT and Tono-Pen, and I-Care and Tono-Pen tonometers were found (r=0.867, P0.05. Both non-gold standard tonometers were affected by CCT; that is, both I-Care and Tono-Pen tonometer values were significantly higher with higher CCT means (>555 μm; MD=−1.282, P555 μm were associated with overestimated IOP values.

Comparison of intraocular pressure measurements with different contact tonometers in young healthy persons.

Science.gov (United States)

Galgauskas, Saulius; Strupaite, Rasa; Strelkauskaite, Ernesta; Asoklis, Rimvydas

2016-01-01

To analyze the correlation of Goldmann applanation tonometer (GAT), I-Care tonometer and Tono-Pen tonometer results in young healthy persons, and to investigate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements recorded with these tonometers. We conducted a pilot clinical study in 78 eyes of 78 subjects aged 22-28 years old (44 women and 34 men; mean age 23.8±1.19y). IOP was measured using GAT, I-Care and Tono-Pen tonometers, followed by measurements of CCT. Statistical analysis was performed using SPSS 20.0. The mean IOPs and standard deviation (±SD) for GAT, I-Care and Tono-Pen were 15.62±2.281 mm Hg, 16.29±2.726 mm Hg and 16.32±2.393 mm Hg, respectively. The mean CCT was 555.15±29.648 µm. Clear positive correlations between GAT and I-Care, GAT and Tono-Pen, and I-Care and Tono-Pen tonometers were found (r=0.867, P0.05). Both non-gold standard tonometers were affected by CCT; that is, both I-Care and Tono-Pen tonometer values were significantly higher with higher CCT means (>555 µm; MD=-1.282, Ptonometers overestimated IOP compared with the GAT values. Either the I-Care or Tono-Pen tonometer could be used instead of GAT because there was no significant difference between their results. Higher CCT values (>555 µm) were associated with overestimated IOP values.

Selected parameters of the corneal deformation in the Corvis tonometer.

Science.gov (United States)

Koprowski, Robert; Lyssek-Boron, Anita; Nowinska, Anna; Wylegala, Edward; Kasprzak, Henryk; Wrobel, Zygmunt

2014-05-03

Contemporary ophthalmology knows many methods of measuring intraocular pressure, namely the methods of non-contact and impression applanation tonometry. In non-contact applanation tonometers, e.g. the Corvis, the corneal flattening is caused by an air puff. Image registration of the corneal deflection performed by a tonometer enables to determine other interesting biomechanical parameters of the eye, which are not available in the tonometer. The measurement of new selected parameters is presented in this paper. Images with an M × N × I resolution of 200 × 576 × 140 pixels were acquired from the Corvis device in the source recording format *.cst. A total of 13'400 2D images of patients examined routinely in the Clinical Department of Ophthalmology, in District Railway Hospital in Katowice, Poland, were analysed in accordance with the Declaration of Helsinki. A new method has been proposed for the analysis of corneal deflection images in the Corvis tonometer with the use of the Canny edge detection method, mathematical morphology methods and context-free operations. The resulting image analysis tool allows determination of the response of the cornea and the entire eyeball to an air puff. The paper presents the method that enables the measurement of the amplitude of curvature changes in the frequency range from 150 to 500 Hz and automatic designation of the eyeball movement direction. The analysis of these data resulted in 3 new features of dynamics of the eye reaction to an air puff. Classification of these features enabled to propose 4 classes of deformation. The proposed algorithm allows to obtain reproducible results fully automatically at a time of 5 s per patient using the Core i5 CPU M460 @ 2.5GHz 4GB of RAM. The paper presents the possibility of using a profiled algorithm of image analysis, proposed by the authors, to measure additional cornea deformation parameters. The new tool enables automatic measurement of the additional new

Intraocular pressure measurement over soft contact lens by rebound tonometer: a comparative study.

Science.gov (United States)

Nacaroglu, Senay Asik; Un, Emine Seker; Ersoz, Mehmet Giray; Tasci, Yelda

2015-01-01

To evaluate the intraocular pressure (IOP) measurements by Icare rebound tonometer over a contact lens in comparison with Goldmann applanation tonometry (GAT). Fifty patients using contact lens were included in this study. One of the eyes of the patients was selected randomly and their IOP were measured by rebound tonometer with and without contact lens (RTCL, RT respectively) and by GAT, as well as their central corneal thickness (CCT) by optical pachymeter. The results of both methods were compared by correlation analysis, general linear method repeated measure and Bland-Altman analysis. Mean IOP values measured by RTCL, RT and GAT were 15.68±3.7, 14.50±3.4 and 14.16±2.8 (Pcontact lens by rebound tonometer was found to be higher than what was measured by GAT. Although this difference is statistically significant, it may be clinically negligible in the normal population.

Assessment of the accuracy and reliability of the Topcon CT80 non-contact tonometer.

Science.gov (United States)

Ogbuehi, Kelechi C

2006-09-01

The reliability of non-contact tonometers has been reported extensively in the literature. This study was designed to assess reliability of the new Topcon CT80 non-contact tonometer in normotensive subjects, using the Goldmann tonometer as the standard. The accuracy of the Topcon CT 80 non-contact tonometer was assessed by comparing its IOP assessments with those of the Goldmann applanation tonometer, on 60 right eyes of young healthy subjects with normal intraocular pressures. Each subject's intraocular pressure was assessed with each technique on two separate occasions, one week apart. The reliability of each technique was determined by the assessment of its inter-session repeatability using the Bland-Altman method. The 95 per cent limits of agreement for the two methods were also determined. No statistically significant difference was found between the average intraocular pressures measured with the two techniques (p > 0.05). The inter-session repeatability indices for the two techniques did not differ significantly (p > 0.05). The mean difference in intraocular measurements between the two techniques was 0.2 +/- 1.5 mmHg (mean +/- SD) and the 95 per cent limits of agreement were -3.14 and +2.74 mmHg, with the non-contact tonometer returning higher readings than the Goldmann tonometer. In this sample of normotensive subjects, the Topcon CT80 non-contact tonometer proved to be accurate and as reliable as the Goldmann tonometer in the assessment of intraocular pressure. Thus, it can be used as an objective clinical method for the assessment of normal intraocular pressure.

Clinical evaluation of the Non-Contact Tonometer Mark II.

Science.gov (United States)

Chauhan, B C; Henson, D B

1988-09-01

The purpose of this investigation was to test the reliability of the American Optical Non-Contact Tonometer Mark II (NCT II) using the Goldmann Applanation Tonometer (GAT) as the validating instrument. The sample contained 102 consecutive patients from our University Eye Clinic, of whom one-half had 4 NCT II measurements first, followed by 4 GAT measurements; the other one-half had 4 GAT measurements first, followed by 4 NCT II measurements. No significant change in intraocular pressure (IOP) was noted over the measurement sequence with either instrument. There was no significant difference between paired NCT II and GAT readings when the NCT II was used first; however, a highly significant difference between paired readings was obtained when the GAT was used first, indicating that the GAT measurement produced a delayed reduction in the IOP. This effect did not occur with the NCT II. Although the NCT II is shown to have a good overall reliability when compared to the GAT in both protocols, the agreement between any two tonometers may be influenced greatly by the very process of taking a measurement and by the dynamic nature of the IOP.

Evaluation of the Keeler Pulsair non-contact tonometer.

Science.gov (United States)

Sponsel, W E; Kaufman, P L; Strinden, T I; DePaul, K L; Bowes, H N; Olander, K W; Barnebey, H S

1989-10-01

The recently-introduced Pulsair non-contact tonometer (Keeler Instruments, Inc, Broomall, PA) was evaluated against the Goldmann applanation tonometer in cannulated post mortem human eyes, and in living subjects at three clinical centers. Statistical analysis of the findings revealed strong linear relationships between Goldmann or manometric and Pulsair intraocular pressure readings, with correlation coefficients ranging from 0.79 to 0.97. However, with the Pulsair reading as the dependent variable, the slope of the relationship in each case was significantly less than 1.0 (range 0.65 to 0.83), while the intercept was positive (range 1.31 to 2.33 mmHg). Thus, the Pulsair tended to read low at intraocular pressure above the normal range. Conversion factors and a calibration table allowing intraocular pressure estimates more comparable to Goldmann tonometry using the current (J-series) Pulsair are provided herein. A calibration algorithm could be integrated into the circuitry of future production models of the Pulsair instrument.

A comparative study of intraocular pressure measurement by three tonometers in normal subjects.

Science.gov (United States)

Prabhakar, S K; Mahesh, B S; Shanthamallappa, M

2013-01-01

Contact Goldmann applanation tonometry (GAT) is gold standard for measuring intraocular pressure; however its routine use is limited by its non-portability and the need for a Slit Lamp Microscope. The Portable Perkins tonometer is also considered gold standard because it is based on the same principles as the GAT. The iCare is a newly introduced, portable, non-contact tonometer (NCT) that measures intraocular pressure (IOP) using a thin metallic probe. To evaluate reliability and accuracy of IOP measurements using iCare and Keeler Pulsair tonometers against Perkins tonometer. A comparative, randomized, prospective clinical study conducted on 166 eyes of 83 (n=83) subjects in the age group 14 to 71 years. The pressures were first recorded by iCare and Pulsair and then by Perkins. The SPSS 11.00 version was used for analysis. Mean pressures and standard deviation (+/-SD) for iCare, Pulsair and Perkins were 14.62(+/- 2.47), 14.53(+/-3.36) and 13.06(+/-2.69) and the Standard Error of the Mean (SEM) was 0.27, 0.36 and 0.30 respectively. There was a good correlation between iCare and Perkins with statistically significant difference (r=0.610, p less than 0.05). Regression analysis was performed. Using the Bland-Altman analysis 95% Limits of Agreement (LoA) for iCare and Pulsair were determined as -6.1 to 2.9 and -4.5 to 7.5 respectively. Although both tonometers overestimated the Perkins values, Pulsair showed a better agreement with Perkins tonometer than iCare tonometer. © NEPjOPH.

Dynamic contour tonometry and goldman applanation tonometry in eyes with keratoconus Tonometria de contorno dinâmico e tonometria de aplanação de goldman em olhos com ceratocone

OpenAIRE

Jackson Barreto Jr; Mirko Babic; Roberto Murad Vessani; Remo Susanna Jr.

2006-01-01

PURPOSE: The dynamic contour tonometer is a nonapplanation contact tonometer designed to be largely independent of the structural properties of the cornea. Theoretically, it may measure intraocular pressure most accurately in abnormally thinner corneas. This study compares intraocular pressure measurements by dynamic contour tonometry with Goldman applanation tonometry in eyes with normal corneas and eyes with advanced keratoconus. METHODS: A comparative case series. Subjects underwent intrao...

Performance of the PT100 noncontact tonometer in healthy eyes

Directory of Open Access Journals (Sweden)

AlMubrad T

2011-05-01

Full Text Available Turki M AlMubradCornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi ArabiaBackground: The purpose of this study was to assess the repeatability and reproducibility of the PT100 noncontact tonometer and to compare its consistency with the Goldmann applanation tonometer (GAT in measuring intraocular pressure (IOP.Methods: Triplicate IOP measurements were obtained on two separate occasions using the PT100 and GAT from randomly selected eyes in 66 healthy volunteers aged 22 ± 1 years. The repeatability and reproducibility of each techniques was assessed. Agreement between the techniques was statistically quantified using intrasession repeatability for each technique as the basis for comparison.Results: Both techniques returned equal IOP values in the first measurement session (15 ± 3 mmHg. The second session showed a mean difference in average IOP (1 ± 0.71. The 95% limits of agreement between the techniques were –5.2 to 5.5 mmHg and –4.0 to 4.7 mmHg (sessions 1 and 2, respectively. These mean differences were not statistically significant (P > 0.05, paired t-test, with the PT100 underestimating IOP measurement by 1.00 mmHg. The mean intrasession IOP for GAT sessions 1 and 2 was 0 ± 0.90 mmHg and 0.04 ± 1.06 mmHg, respectively, and the corresponding mean IOP measurement difference for the PT100 was –0.06 ± 0.96 and –0.39 ± 0.94 mmHg (sessions 1 and 2, respectively; P > 0.05, paired t-test. Repeatability coefficients for the GAT IOP measurements were 1.8 mmHg and 2.1 mmHg for sessions 1 and 2, while the PT100 repeatability coefficient was 1.9 mmHg and 1.8 mmHg for sessions 1 and 2, respectively. The intrasession repeatability coefficient of both techniques for test–retest differences were within ±5 mmHg.Conclusion: The PT100 noncontact tonometer produced greater repeatability than the GAT in assessment of IOP, whereas GAT resulted in more reproducible

Possible iatrogenic transmission of Creutzfeldt-Jakob disease via tonometer tips: a review of the literature.

Science.gov (United States)

Walia, J S; Chronister, C L

2001-10-01

Tonometer tips are used by optometrists to measure intraocular pressures. The recommended procedure of soaking in bleach solution kills bacteria and certain viruses, such as human immunodeficiency virus, herpes simplex virus-1 and herpes simplex virus-2, adenovirus 8, and hepatitis B, from the tip. Conversely, recommendations made in literature to sterilize equipment that may have come in contact with virus-contaminated tissue from patients with Creutzfeldt-Jakob disease have a somewhat tougher requirement. Autoclaving for 1 hour at a temperature of at least 120 degrees C (15 psi), or a 1-hour exposure to 0.5% sodium hypochlorite (a 10-fold dilution of household bleach) should provide excellent disinfection. One-hour exposure to 1 N Sodium hydroxide has also been mentioned in the literature. Studies have shown that corneas of guinea pigs with Cruetzfeldt-Jakob disease (C-J disease) are infectious. Infected corneas have been shown to cause transmission via corneal transplants, and via experimental placement of infected guinea pig's cornea into the anterior chamber of uninfected guinea pigs. Many researchers have strongly suggested that C-J disease can be iatrogenically transmitted via applanation tonometer tips. An epidemiologic case-controlled study found statistically significant odds ratio for intraocular pressure testing in the medical history of patients with C-J disease. Even though there have not been any proven studies confirming iatrogenic transmission through tonometer tips, optometrists should be cautious if a patient has C-J disease, or manifests symptoms of C-J disease and use alternatives to Goldmann applanation tonometry.

Correlations between different tonometries and ocular biometric parameters in patients with primary congenital glaucoma.

Science.gov (United States)

Mendes, Marcio Henrique; Betinjane, Alberto Jorge; Quiroga, Veronica Andrea

2013-01-01

To identify the correlation between the difference of intraocular pressure measurements (IOP) obtained using the Goldmann applanation tonometer (GAT) and three others tonometers (Handheld applanation tonometer - HAT, Dynamic contour tonometer - DCT and Tono-Pen®) with biometric characteristics (corneal diameter, pachymetry, keratometry and axial length) in patients with congenital glaucoma. A cross-sectional study was performed on 46 eyes from 46 patients with congenital glaucoma. IOP measurements were obtained in all patients using GAT, HAT, DCT and Tono-Pen®. Keratometry, pachymetry, biometry and corneal diameter measurements were performed after the IOP measurement. The order of the tonometries was randomized. The correlations between the differences of IOP values of GAT and the other tonometers (Delta-IOP), and the different biometric parameters were studied. Tono-Pen® Delta IOP revealed moderate positive correlation to keratometry (r=0.41, p=0.004). The other Delta-IOPs showed no correlation with any of the biometric characteristics evaluated. IOP differences between GAT (gold standard) and GAT, HAT, DCT or Tono-Pen tonometers seem not to correlate with majority of ocular biometric characteristics. The only exception was the keratometry, which correlated in a positive and moderate way with Tono-Pen® Delta-IOP. This result suggests that the differences of IOP values of Tono-Pen® and GAT increase with the steepness of the cornea.

Effect of central corneal thickness on intraocular pressure and comparison of Topcon CT-80 non-contact tonometry with Goldmann applanation tonometry.

Science.gov (United States)

Mansoori, Tarannum; Balakrishna, Nagalla

2018-03-01

To compare intraocular pressure (IOP) measurements obtained with the Topcon CT-80 non-contact tonometer (NCT) and Goldmann applanation tonometer (GAT), in different ranges of IOP in normal and glaucoma subjects, and to assess the influence of central corneal thickness (CCT) on the IOP measurements in Asian Indian eyes. Four hundred and two eyes of 402 subjects (193 newly diagnosed primary open angle glaucoma [POAG] and 209 normal) were enrolled for this prospective study. For each eye, IOP was measured with GAT by a glaucoma specialist and NCT by a trained optometrist. The IOP values were compared among the tonometers in the three different IOP ranges (≤ 12 mmHg, 13-20 mmHg and ≥ 21 mmHg) using Bland-Altman graphs. Correlation between GAT and NCT was assessed by Pearson correlation co-efficient. CCT was measured with ultrasound pachymetry and its correlation with GAT and NCT was analysed using linear regression analysis. The mean paired difference of IOP between NCT and GAT was 1.556 ± 2.69 mmHg (r = 0.26, p = 0.006) at IOP range of ≤ 12 mmHg, -1.665 ± 2.6 mmHg (r = 0.51, p tonometer and that the IOP readings obtained with these tonometers are not interchangeable. © 2017 Optometry Australia.

Applanation tonometry in silicone hydrogel contact lens wearers.

Science.gov (United States)

Allen, R J; Dev Borman, A; Saleh, G M

2007-12-01

Previous studies have investigated intraocular pressure (IOP) measurements through conventional soft (hydrogel) therapeutic contact lenses, and have found that an accurate IOP can be recorded in normal eyes, and in eyes with abnormal anterior segments. The IOP measurement through soft contact lenses may be affected by the water content and centre thickness of the lens. Silicone hydrogel contact lenses are now being used as therapeutic contact lenses due to their high oxygen permeability. The purpose of this study is to investigate if IOP can be accurately measured in a subject wearing a silicone hydrogel contact lens. In a cohort study, the IOP was measured with a Goldmann applanation tonometer without a contact lens and then repeated with a hydrogel contact lens in situ. The IOP of 20 eyes of 10 volunteers with no ocular pathology was measured. The mean difference (+/-S.D.) found between IOP measurement with (mean 15.55+/-1.70 mmHg) and without (mean 16.05+/-1.90 mmHg) contact lens was found to be -0.5+/-0.89 mmHg. Statistical analysis was performed which revealed a correlation coefficient of 0.89. No significant statistical difference was found between the two groups with paired t-test (p=0.19). Accurate measurement of IOP by applanation tonometry can be achieved through a silicone hydrogel contact lens.

[Contemporary possibilities of intraocular pressure measurement].

Science.gov (United States)

Hornová, J; Baxant, A

2013-10-01

Authors introduced current possibilities of measuring intraocular pressure (IOP). A list of available methods of monitoring IOP is published; contact measurement method IOP directly on the cornea, but also over upper lid, methodology of minimal contact and non-contact measurement. Following contact methods are described; former measurements of IOP by impression Schiotz tonometer and the current methodology applanation. So far as the gold standard measurement Goldmann applanation tonometer (GAT) is considered, another methodology with applanation measurements are compared: Pascal dynamic contoured tonometer (DCT ), BioResonator - resonant applanation tonometer (ART ), digital applanation tonometer Tonopen and last hit: continuous measurement of IOP by Sensimed Triggerfish. Orientation and rapid assessment is palpation pressure control over the lid and measuring by tonometer Diaton. Rebound tonometer (RBT) iCare belongs to measurements with minimal contact, no need anesthetic drops and fluorescein, therefore a self - home version of IOP measurements (Icare ONE) is developed. Non-contact measurement of IOP by different pneumotonometers is popular for screening assessment of IOP. Reichert Ocular Response Analyzer (ORA) is a non-contact applanation IOP measurement and reveals additional properties of the cornea. In the discussion of a range methodology is evaluated, the experience of other authors and their own experience is compared. For monitoring of patients is necessary to select the most suitable methodology, measure repeatedly and accurately to allow long-term monitoring of intraocular pressure.

Intraocular pressure readings obtained through soft contact lenses using four types of tonometer.

Science.gov (United States)

Takenaka, Joji; Kunihara, Eriko; Rimayanti, Ulfah; Tanaka, Junko; Kaneko, Makoto; Kiuchi, Yoshiaki

2015-01-01

To compare the reliability and accuracy of intraocular pressure (IOP) measured while wearing soft contact lenses (SCLs) using a non-contact tonometer (NCT), Goldmann applanation tonometer (GAT), iCare rebound tonometer (RBT) and the Tono-Pen XL. Twenty-six healthy subjects were examined. The IOP was measured using NCT, GAT, RBT, and the Tono-Pen XL, while the subjects wore SCLs -5.00 D, -0.50 D and +5.00 D. Bland-Altman plots and a regression analysis were used to compare the IOPs obtained with those instruments and the IOPs of the naked eyes measured using GAT (the standard IOPs in this study). The IOPs obtained by the Tono-Pen XL while the subjects were wearing -5.00 D, -0.50 D, and +5.00 D SCLs were significantly higher than those of the naked eyes obtained using GAT. RBT showed that the IOPs were similar to the GAT standard IOPs under all conditions. The IOPs measured with NCT and GAT while the subjects were wearing -5.00 D and -0.50 D SCLs were similar to the GAT standard IOPs. The IOPs obtained with RBT and NCT while the subjects were wearing -5.00 D and -0.50 D SCLs exhibited a good correlation with the standard IOPs. The NCT and RBT are best when measuring IOP through hydrogel SCLs.

A comparison of the Goldmann applanation and non-contact (Keeler Pulsair EasyEye) tonometers and the effect of central corneal thickness in indigenous African eyes.

Science.gov (United States)

Babalola, O E; Kehinde, A V; Iloegbunam, A C; Akinbinu, T; Moghalu, C; Onuoha, I

2009-03-01

The Keeler Pulsair EasyEye non-contact tonometer (NCT) was introduced into practice at Rachel Eye Center Abuja, Nigeria, where the patients are indigenous Africans. This was compared to the 'gold standard' Goldmann applanation tonometer (GAT) to determine if the instrument was accurate in Africans, with particular reference to the influence of central corneal thickness (CCT). 174 eyes of 88 patients were analysed. Pachymetry was performed using Sonomed PacScan AP300, and GAT with the Haag Streit R-900. Pachymetric corrections of NCT (NCTc) and GAT (GATc) were carried out with the Sonomed algorithm. Pearson's correlation r, linear regression analysis, Student t-test and Bland-Altman analysis were used to compare the instruments. Mean NCT readings were similar (17.36 mmHg) to mean GAT (17.42 mmHg; p = 0.769). GAT/NCT correlation coefficient, r, was 0.883 as compared with 0.868 for GATc/NCTc. The linear regression equation was GAT = 2.79 + 0.84*NCT (r(2) = 0.78). Forty-five per cent of differences were within 1 mmHg, while 79% were within 3 mmHg. This was similar to findings in some studies on Caucasians. Bland-Altman analysis however suggested that the spread of differences was wider than in those studies. Outliers (differences more than 5 mmHg) sometimes reflected difficulties encountered with GAT in routine practice. Mean CCT was 537.9 microm, (S.D. 38.4, 95% confidence interval 532.1-543.7 microm) and CCT appeared lower than in Caucasians. Both GAT and NCT IOP tended to rise with increasing CCT but NCT had a greater tendency to do so. Regression analysis suggested that NCT IOP increased by 0.6 mmHg for every 10 mum increase in CCT, compared to 0.4 mmHg for GAT. Thirty-eight per cent of the patients preferred NCT as opposed to 25% GAT. The Keeler Pulsair EasyEye gives reliable measurements of IOP in African eyes but is significantly affected by CCT. Particularly in borderline cases where management decisions have to be taken, it may be necessary to have pachymetric

Reliability of tonosafe disposable tonometer prisms: clinical implications from the Veterans Affairs Boston Healthcare System Quality Assurance Study.

Science.gov (United States)

Thomas, V; Daly, M K; Cakiner-Egilmez, T; Baker, E

2011-05-01

Given the Veterans Affairs Boston Healthcare System's recent introduction of single-use Tonosafe disposable tonometer prisms as an alternative to Goldmann applanation tonometers (GATs), this study had two aims: to conduct a large-scale quality assurance trial to assess the reliability of intraocular pressure (IOP) measurements of the Tonosafe disposable tonometer compared with GAT, particularly at extremes of pressure; to evaluate the suitability of Tonosafe disposable tonometer prisms as an acceptable substitute for GATs and for clinic-wide implementation in an academic tertiary referral setting. Ophthalmology resident physicians measured the IOPs of patients in general and specialty eye clinics with the Tonosafe disposable tonometer and GAT. Tonosafe test-retest reliability data were also collected. A retrospective review of patient charts and data analysis were performed to determine the reliability of measurements. The IOPs of 652 eyes (326 patients) were measured with both GAT and Tonosafe, with a range of 3-34 mm Hg. Linear regression analysis showed R=0.93, slope=0.91, both of which supported the proposed hypothesis, and the y-intercept=-1.05 was significantly different from the hypothesized value. The Tonosafe test-retest repeatability (40 eyes of 40 patients), r=0.977, was very high, which was further supported by linear regression slope=0.993, y-intercept=0.118, and a Tonosafe repeatability coefficient of 2.06, similar to GAT repeatability. The IOP measurements by Tonosafe disposable prisms correlated closely with Goldmann measurements, with similar repeated measurement variability to GAT. This suggests that the Tonosafe is an acceptable substitute for GAT to measure IOP in ophthalmology clinic settings.

Accuracy of intraocular pressure measurements in dogs using two different tonometers and plano therapeutic soft contact lenses.

Science.gov (United States)

Ahn, Jeong-Taek; Jeong, Man-Bok; Park, Young-Woo; Kim, Se-Eun; Ahn, Jae-Sang; Lee, Yes-Ran; Lee, Eui-Ri; Seo, Kangmoon

2012-03-01

To compare and evaluate the accuracy of intraocular pressure (IOP) measured through a therapeutic contact lens, using applanation (TonoPen XL(®)) and rebound (TonoVet(®)) tonometers in enucleated dog eyes. A total of 30 enucleated eyes from 15 beagle dogs. To measure accurate IOP, the anterior chamber of each enucleated eye was cannulated with two 26-gauge needles and two polyethylene tubes were connected vertically to an adjustable reservoir bag of normal saline and a pressure transducer. IOP was measured by the TonoPen XL(®) followed by the TonoVet(®) without a contact lens. After a contact lens was applied to the cornea, IOP was re-measured in the same order. Three consecutive IOP measurements were performed using both tonometers. Without the contact lens, the IOP values obtained by both tonometers correlated well according to the regression analysis (TonoVet(®): γ(2) = 0.98, TonoPen XL(®): γ(2) = 0.97, P contact lens was applied to the cornea. Bland-Altman analysis was used to determine the lower and upper limits of agreement (TonoVet(®): -29.7 and +21.1 mmHg, TonoPen XL(®): -3.9 and +3.6 mmHg) between the two devices. This study suggests that the TonoPen XL(®) is a useful tonometer for dogs wearing therapeutic contact lenses, and importantly, contact lenses would not need to be removed prior to IOP measurement. © 2012 American College of Veterinary Ophthalmologists.

Intraocular pressure readings obtained through soft contact lenses using four types of tonometer

Directory of Open Access Journals (Sweden)

Takenaka J

2015-10-01

Full Text Available Joji Takenaka,1 Eriko Kunihara,1 Ulfah Rimayanti,2 Junko Tanaka,3 Makoto Kaneko,4 Yoshiaki Kiuchi1 1Department of Ophthalmology and Visual Science, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan; 2Faculty of Medicine and Health Sciences, UIN Alauddin Makassar, South Sulawesi, Indonesia; 3Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan; 4Graduate School of Engineering, Osaka University, Osaka, Japan Purpose: To compare the reliability and accuracy of intraocular pressure (IOP measured while wearing soft contact lenses (SCLs using a non-contact tonometer (NCT, Goldmann applanation tonometer (GAT, iCare rebound tonometer (RBT and the Tono-Pen XL.Methods: Twenty-six healthy subjects were examined. The IOP was measured using NCT, GAT, RBT, and the Tono-Pen XL, while the subjects wore SCLs -5.00 D, -0.50 D and +5.00 D. Bland–Altman plots and a regression analysis were used to compare the IOPs obtained with those instruments and the IOPs of the naked eyes measured using GAT (the standard IOPs in this study.Results: The IOPs obtained by the Tono-Pen XL while the subjects were wearing -5.00 D, -0.50 D, and +5.00 D SCLs were significantly higher than those of the naked eyes obtained using GAT. RBT showed that the IOPs were similar to the GAT standard IOPs under all conditions. The IOPs measured with NCT and GAT while the subjects were wearing -5.00 D and -0.50 D SCLs were similar to the GAT standard IOPs. The IOPs obtained with RBT and NCT while the subjects were wearing -5.00 D and -0.50 D SCLs exhibited a good correlation with the standard IOPs.Conclusion: The NCT and RBT are best when measuring IOP through hydrogel SCLs. Keywords: soft contact lens, intraocular pressure, rebound tonometer, non-contact tonometer

Tonometer calibration in Brasília, Brazil Calibragem de tonômetros em Brasília, Brasil

Directory of Open Access Journals (Sweden)

Fernanda Pires da Silva Abrão

2009-06-01

Full Text Available PURPOSE: To determine calibration errors of Goldmann applanation tonometers in ophthalmic clinics of Brasília, Brazil, and correlate the findings with variables related to tonometers model and utilization. METHODS: Tonometers from ophthalmic clinics in Brasília, Brazil, were checked for calibration errors. A standard Goldmann applanation tonometer checking tool was used to asses the calibration error. Only one trained individual made all verifications, with a masked reading of the results. Data on the model, age, daily use, frequency of calibration checking and the nature of the ophthalmic department - private or public - were collected and correlated with the observed errors. RESULTS: One hundred tonometers were checked for calibration. Forty seven percent (47/100 were out of 1 mmHg range at least at one point checking. Tonometers mounted to slit lamp, with less than 5 years, used in less than 20 patients daily, that had a calibration check on a yearly basis, and those from private office exhibit a lower rate of inaccuracy, but only the first variable was statistically significant. Sixty one percent of tonometers on public hospitals were out of calibration. CONCLUSION: Calibration of tonometers in the capital of Brazil is poor; those from general hospitals are worst, and this fact can lead to inaccurate detection and assessment of glaucoma patients, overall in the population under government assistance.OBJETIVOS: Determinar os erros de calibração dos tonômetros de aplanação de Goldmann em clínicas oftalmológicas de Brasília, Brasil, e correlacioná-los a variáveis relativas ao modelo e à utilização dos aparelhos. MÉTODOS: Tonômetros de clínicas oftalmológicas de Brasília tiveram a calibragem aferida usando um cilindro padrão fornecido pelo fabricante dos aparelhos. Todas as aferições foram realizadas por um só examinador previamente treinado e a leitura das medidas foi mascarada por um observador independente. As medidas

Intraocular pressure monitoring by rebound tonometry in children with myopia.

Science.gov (United States)

Weng, Jenchieh; Tsai, I-Lun; Kuo, Li-Lin; Tsai, Ching-Yao; Woung, Lin-Chung; Hsiao, Ya-Chuan

2017-01-01

Topical atropine treatment is generally accepted to retard the progression of myopia, but it is associated with side effects such as photophobia and elevation of intraocular pressure (IOP). IOP measurements in children are challenging. The traditional applanation tonometry by direct contact with the cornea will require patient's cooperation. The rebound tonometer, using a dynamic electromechanical method for measuring IOP, shows good correlation with traditional tonometry. The purpose of this study is to evaluate the IOP of myopic children under atropine treatment using rebound tonometer and to compare the characteristics between rebound tonometry and applanation tonometry. This study is a prospective study measuring IOP by rebound tonometer in myopic children under regular low-dose atropine treatment. We recruited children with refraction error showing myopia over -0.5 D with 0.15%, 0.3%, or 0.5% atropine eye drops use every night or every other night for myopia control. Children with treatment duration of atropine tonometer (Tono-Pen XL, Reichert) and rebound tonometer (ICARE). The reliability of rebound tonometer was analyzed with percentage. Comparison of IOP between rebound tonometer and applanation tonometry was presented. The rebound tonometry was well tolerated by all participants and caused no complaints, discomfort, or adverse events. Totally 42 myopic eyes of 42 subjects were included in the study. The average age of these participants was 10 years old, range from 5 to 16. Median = 10 years old. The average IOP of the right eye by rebound tonometer was 17.4 ± 3 mmHg, and 17.1 ± 3 mmHg by applanation tonometry. Nearly 19%, 33%, and 24% of difference of IOP readings between rebound tonometer and Tono-Pen applanation are within 0 mmHg, 1 mmHg, and 1-2 mmHg, respectively. Rebound tonometry has good correlation with applanation tonometry and 76.1% of differences between two tonometers are <2 mmHg. The advantage of drop-free rebound tonometry has made it

The non-contact ("air puff") tonometer: variability and corneal staining.

Science.gov (United States)

Myers, K J; Scott, C A

1975-01-01

We investigated the possibility of significant corneal trauma (as revealed by slit lamp observation of the fluorescein instilled eye), and massage effects following determination of intraocular pressure with the A. O. Non-Contact tonometer (NCT). Fifteen different, normal human eyes were each applanated 150 successive times with the NCT; leading to the conclusion that only minor, superficial corneal epithelial defects sometimes resulted and that, in line with other studies, the initially higher readings (about 1 mm), obtained with the NCT, were most likely due to patient apprehension, while the subsequently lower readings represented patient acceptance of the process and were not a result of true aqueous massage. As in an earlier study, we found the instrument's variability to be about plus and minus 1 or plus and minus 2 mm and probably due to the subject's own cardiac cycle.

Influence of corneal thickness on comparative intraocular pressure measurements with Goldmann and non-contact tonometers in keratoconus.

Science.gov (United States)

Stabuc Silih, Mirna; Hawlina, Marko

2003-12-01

The influence of corneal thickness and curvature on the difference between intraocular pressure (IOP) measurements obtained with non-contact (NCT) and those with the Goldmann applanation tonometer (GAT) was studied in patients with keratoconus. We examined 113 patients with keratoconus. IOP was measured by the Canon TX 10 non-contact tonometer and the Goldmann tonometer, corneal curvature and thickness were obtained by Humphrey Automatic Refractometer Keratometer and Orbscan Version 3.0 Bausch & Lomb Surgical. The IOP measured by NCT was significantly lower than that measured by GAT. The mean pachymetry of the thinnest point was 423.15 +/- 98.43 microm for the right eyes and 426.7 +/- 93.88 microm for the left eyes. The difference between NCT-GAT and corneal thickness showed a significant negative correlation (r = - 0.427, p < 0.0001; t = - 3.677, p < 0.0001). Values of NCT measurements were significantly increasing with corneal thickness (F = 6.505, p < 0.0001 for right eyes and F = 4.37, p = 0.004 for left eyes), whilst GAT measurements did not show a significant influence of the corneal thickness. The keratometry had no effect on the difference between NCT-GAT measurements (t = 1.090, p = 0.278). The thin cornea has more influence on the measurement with NCT than GAT. The relative precision of NCT compared with GAT seems to be influenced by the corneal thickness.

Intraocular pressure menagement with transpalpebral tonometry

OpenAIRE

Toker, Mustafa İlker; Dursun, Ayhan

2013-01-01

Applanation tonometry is the method of measuring intraocular pressure (IOP) with instruments the corneal surface. The Goldmann applanation tonometer (GAT) is regarded as the “gold standard’’ of measuring IOP. An irregular and opaque corneal surface compromises IOP measurement by Goldmann applanation tonometry. In such cases accurate measurement without corneal contact would be applicable. The transpalpebral tonometer is new method and measures IOP without corneal contact through the eyelid....

Transpalpebral tonometri ile göz içi basıncı ölçülmesi

OpenAIRE

Toker, Mustafa; Dursun, Ayhan

2012-01-01

Applanation tonometry is the method of measuring intraocular pressure (IOP) with instruments the corneal surface. The Goldmann applanation tonometer (GAT) is regarded as the “gold standard’’ of measuring IOP. An irregular and opaque corneal surface compromises IOP measurement by Goldmann applanation tonometry. In such cases accurate measurement without corneal contact would be applicable. The transpalpebral tonometer is new method and measures IOP without corneal contact through the eyelid....

Intraocular pressure measurement over soft contact lens by rebound tonometer:a comparative study

Directory of Open Access Journals (Sweden)

Senay Asik Nacaroglu

2015-06-01

Full Text Available AIM: To evaluate the intraocular pressure (IOP measurements by Icare rebound tonometer over a contact lens in comparison with Goldmann applanation tonometry (GAT.METHODS: Fifty patients using contact lens were included in this study. One of the eyes of the patients was selected randomly and their IOP were measured by rebound tonometer with and without contact lens (RTCL, RT respectively and by GAT, as well as their central corneal thickness (CCT by optical pachymeter. The results of both methods were compared by correlation analysis, general linear method repeated measure and Bland-Altman analysis.RESULTS: Mean IOP values measured by RTCL, RT and GAT were 15.68±3.7, 14.50±3.4 and 14.16±2.8 (P<0.001, respectively. Mean IOP by RTCL was significantly higher than the measurements implemented by RT and GAT (P<0.001, while there was no difference between the measurements by GAT and RT (P=0.629. There was a good level of positive correlation between GAT and RTCL as well as RT (r=0.786 P<0.001, r=0.833 P<0.001, respectively. We have observed that CCT increase did not show any correlation with the differences of the measurements between RTCL and RT (P=0.329, RTCL and GAT (P=0.07 as well as RT and GAT (P=0.189 in linear regression model.CONCLUSION: The average of the measurements over contact lens by rebound tonometer was found to be higher than what was measured by GAT. Although this difference is statistically significant, it may be clinically negligible in the normal population.

Comparative study of three non-contact tonometers and the Goldmann tonometer.

Science.gov (United States)

Moreno-Montañés, J; Gómez-Demmel, E; Lajara-Blesa, J; Aliseda-Pérez de Madrid, D

1994-01-01

The main objective of this study was to find out how well three non-contact tonometers (Pulsair, Xpert-NCT and CT-20) compare with the Goldmann tonometer (GT). Sensitivity, specificity, positive and negative predictive values were all evaluated for an intraocular pressure (IOP) > or = 21 mm Hg. We also calculated the mean IOP, the correlation and the dispersion of the results. The difficulty in using the instruments, the patient's attitude and subjective comfort of IOP measuring were also evaluated. We describe the advantages and shortcomings of non-contact tonometers as screening tools to detect elevated IOP in the general population.

Misleading Goldmann applanation tonometry in a post-LASIK eye with interface fluid syndrome

Directory of Open Access Journals (Sweden)

Senthil Sirisha

2010-01-01

Full Text Available A 21-year-old myope presented with decreased vision and corneal edema following vitreoretinal surgery for retinal detachment. While intraocular pressure (IOP measurement with Goldmann applanation tonometer (GAT was low, the digital tonometry indicated raised pressures. An interface fluid syndrome (IFS was suspected and confirmed by clinical exam and optical coherence tomography. A tonopen used to measure IOP through the peripheral cornea revealed elevated IOP which was the cause of the interface fluid. Treatment with IOP-lowering agents resulted in complete resolution of the interface fluid. This case is being reported to highlight the fact that IFS should be suspected when there is LASIK flap edema and IOP readings using GAT are low and that GAT is not an optimal method to measure IOP in this condition. Alternative methods like tonopen or Schiotz tonometry can be used.

Open source software for the analysis of corneal deformation parameters on the images from the Corvis tonometer.

Science.gov (United States)

Koprowski, Robert

2015-04-11

The software supplied with the Corvis tonometer (which is designed to measure intraocular pressure with the use of the air-puff method) is limited to providing basic numerical data. These data relate to the values of the measured intraocular pressure and, for example, applanation amplitudes. However, on the basis of a sequence of images obtained from the Corvis tonometer, it is possible to obtain much more information which is not available in its original software. This will be presented in this paper. The proposed software has been tested on 1400 images from the Corvis tonometer. The number of analysed 2D images (with a resolution of 200 × 576 pixels) in a sequence is arbitrary. However, in typical cases there are 140 images. The proposed software has been written in Matlab (Version 7.11.0.584, R2010b). The methods of image analysis and processing and in particular edge detection and the fast Fourier transform have been applied. The software allows for fully automatic (1) acquisition of 12 new parameters previously unavailable in the original software of the Corvis tonometer. It also enables off-line (2) manual and (3) automatic browsing of images in a sequence; 3D graph visualization of: (4) the corneal deformation and (5) eyeball response; 6) change of the colour palette; (7) filtration and (8) visualization of selected measured values on individual 2D images. In addition, the proposed software enables (9) to save the obtained results for further analysis and processing. The dedicated software described in this paper enables to obtain additional new features of corneal deformations during intraocular pressure measurement. The software can be applied in the diagnosis of corneal deformation vibrations, glaucoma diagnosis, evaluation of measurement repeatability and others. The software has no licensing restrictions and can be used both commercially and non-commercially without any limitations.

Inter-instrument agreement and influence of central corneal thickness on measurements with Goldmann, pneumotonometer and noncontact tonometer in glaucomatous eyes.

Science.gov (United States)

Gupta, Viney; Sony, Parul; Agarwal, Harish C; Sihota, Ramanjit; Sharma, Ajay

2006-12-01

This study was conducted to compare the intraocular pressure (IOP) measurements by the Goldman applanation tonometer (GAT), non contact tonometer (NCT) and the ocular blood flow (OBF) pneumotonometer in different IOP ranges in glaucomatous eyes. The effect of central corneal thickness (CCT) on IOP measurement in chronic glaucomatous eyes using the three different tonometers was also evaluated. IOP measurements of 130 eyes of primary glaucoma patients were performed using GAT by an ophthalmologist while NCT and OBF-pneumotonometer measurements were performed by an experienced optometrist. The IOP values were compared amongst the three instruments in the three different IOP ranges (0-18 mmHg, > 18 to 25 mmHg, > 25 mmHg). CCT was also measured in all patients. The mean of paired difference between GAT and NCT was 0.9 +/- 3.1 mmHg while that between GAT and OBF-pneumotonometer was 0.3 +/- 3.4 mmHg. The OBF-pneumotonometer and NCT were more affected by corneal thickness (0.41 mmHg and 0.4 mmHg / 10 micro corneal thickness respectively) while GAT was the least affected by corneal thickness (0.3 mmHg / 10 micro corneal thickness) though the difference was not statistically significant ( P =0.42). With appropriate correction for corneal thickness the NCT and OBF-pneumotonometer can be used as reliably as GAT in following up glaucomatous patients.

[Transpalpebral tonometry with a digital tonometer in healthy eyes and after penetrating keratoplasty].

Science.gov (United States)

Amm, M; Hedderich, J

2005-01-01

The Goldmann applanation technique established itself as gold standard for clinical intraocular pressure (IOP) measurement. But the device measures by corneal touch and presupposes corneal conditions within a normal range. So precise determination of IOP is crucial in corneal disorders and after corneal surgery. This pilot study presents tonometry data of normal and postkeratoplasty eyes measured transpalpebrally with a digital tonometer in comparison to Goldmann tonometry. The TGDc-01 tonometer is based on a ballistic principle of measurement. IOP was measured in 50 healthy eyes (group 1) and 40 eyes after penetrating keratoplasty (group 2) first by the TGDc-01 and after 3 minutes by Goldmann tonometry (Haag-Streit). Subjective refraction, keratometry and ultrasonic pachymetry were performed in all eyes. The IOP measurements in the postkeratoplasty eyes were done when corneal epithelium was fully closed and only a medium suture edema could be observed. The Pearson's product-moment correlation was r=0,46 for group 1 and 0,65 for group 2. Using the concordance correlation coefficient the value showed a reproducibility index of r(c)=0,44 in group 1 and r(c)=0,60 in group 2. Following the Bland-Altman-analysis 58% of the cases in group 1 had a difference between the two instruments of maximum 3 mmHg. In group 2, 53,5% of the eyes showed an absolute difference between Goldmann and TDGc-01 of 3 mmHg or less. A transpalpebral measurement technique-avoiding corneal contact-seems to be an alternative choice in patients with corneal pathologies and after corneal surgery. The TGDc-01 tonometer provided mostly similar results compared to the Goldmann device, but with fluctuations. Keeping the deviations between the two methods in mind we recommend, however, the use of the transpalpebral approach only in combination with other techniques (palpation, indentation) to obtain enough reliability of IOP information in problem eyes.

Inter-instrument agreement and influence of central corneal thickness on measurements with Goldmann, pneumotonometer and noncontact tonometer in glaucomatous eyes

Directory of Open Access Journals (Sweden)

Gupta Viney

2006-01-01

Full Text Available Purpose: This study was conducted to compare the intraocular pressure (IOP measurements by the Goldman applanation tonometer (GAT, non contact tonometer (NCT and the ocular blood flow (OBF pneumotonometer in different IOP ranges in glaucomatous eyes. The effect of central corneal thickness (CCT on IOP measurement in chronic glaucomatous eyes using the three different tonometers was also evaluated. Materials and Methods: IOP measurements of 130 eyes of primary glaucoma patients were performed using GAT by an ophthalmologist while NCT and OBF-pneumotonometer measurements were performed by an experienced optometrist. The IOP values were compared amongst the three instruments in the three different IOP ranges (0-18 mmHg,> 18 to 25 mmHg, > 25 mmHg. CCT was also measured in all patients. Results: The mean of paired difference between GAT and NCT was 0.9 ± 3.1 mmHg while that between GAT and OBF-pneumotonometer was 0.3 ± 3.4 mmHg. The OBF-pneumotonometer and NCT were more affected by corneal thickness (0.41 mmHg and 0.4 mmHg / 10 µ corneal thickness respectively while GAT was the least affected by corneal thickness (0.3 mmHg / 10 µ corneal thickness though the difference was not statistically significant ( P =0.42. Conclusion: With appropriate correction for corneal thickness the NCT and OBF-pneumotonometer can be used as reliably as GAT in following up glaucomatous patients.

[Contact glass tonometer].

Science.gov (United States)

Dekker, P W; Kanngiesser, H; Robert, Y C

1996-05-01

This paper presents a tonometer built into a contactlens, which allows to measure the eye-pressure and to perform ophthalmoscopy at the same time. Artificially induced changes of the eye-pressure and their influence on the visible fundus can now be checked simultaneously. The contactlens-tonometer (CGT) also is able to record continuously the pulse-curve, which can indicate any circulatory problem. So, the device is expected to give us additional diagnostic criteria of early glaucoma. Each ophthalmologyst in the field will be able to perform with this device a oculodynamometry in an easy way. By this it is possible to estimate the pressure-tolerance of the optic disk from glaucoma-patients. There have been taken some measurements on enucleated human eyes, comparing our device with a Statham-transducer in the vitreous. We found a good correlation. In a second step, we made measurements (65) on healthy volunteers, comparing the device with Perkins-Tonometry. We found a correlation (R = 0.58). The error of the measurements was about +/- 3 mm Hg. Considering both, the deviation of the Perkins-Tonometer with which our results were compared, and the fact of a good correlation (R = 0.999) in the study with the enucleated human eyes, we found that the contact-lens-tonometer measures the intraocular pressure exactly. In future studies, we want to analyze the dynamic component of the measurements.

Intraocular pressure and ocular pulse amplitude using dynamic contour tonometry and contact lens tonometry.

Science.gov (United States)

Hoffmann, Esther M; Grus, Franz-H; Pfeiffer, Norbert

2004-03-23

The new Ocular Dynamic Contour Tonometer (DCT), investigational device supplied by SMT (Swiss Microtechnology AG, Switzerland) allows simultaneous recording of intraocular pressure (IOP) and ocular pulse amplitude (OPA). It was the aim of this study to compare the IOP results of this new device with Goldmann tonometry. Furthermore, IOP and OPA measured with the new slitlamp-mounted DCT were compared to the IOP and OPA measured with the hand-held SmartLens,a gonioscopic contact lens tonometer (ODC Ophthalmic Development Company AG, Switzerland). Nineteen healthy subjects were included in this study. IOP was determined by three consecutive measurements with each of the DCT, SmartLens, and Goldmann tonometer. Furthermore, OPA was measured three times consecutively by DCT and SmartLens. No difference (P = 0.09) was found between the IOP values by means of DCT (mean: 16.6 mm Hg, median: 15.33 mm Hg, SD: +/- 4.04 mm Hg) and Goldmann tonometry (mean: 16.17 mm Hg, median: 15.33 mm Hg, SD: +/- 4.03 mm Hg). The IOP values of SmartLens (mean: 20.25 mm Hg, median: 19.00 mm Hg, SD: +/- 4.96 mm Hg) were significantly higher (P = 0.0008) both from Goldmann tonometry and DCT. The OPA values of the DCT (mean: 3.08 mm Hg, SD: +/- 0.92 mm Hg) were significantly lower (P = 0.0003) than those obtained by SmartLens (mean: 3.92 mm Hg, SD: +/- 0.83 mm Hg). DCT was equivalent to Goldmann applanation tonometry in measurement of IOP in a small group of normal subjects. In contrast, SmartLens (contact lens tonometry) gave IOP readings that were significantly higher compared with Goldmann applanation tonometer readings. Both devices, DCT and SmartLens provide the measurement of OPA which could be helpful e.g. for the management of glaucoma.

Intraocular pressure measurement by three different tonometers in primary congenital glaucoma.

Science.gov (United States)

Zareei, Athar; Razeghinejad, Mohammad Reza; Nowroozzadeh, Mohammad Hosein; Mehrabi, Yadollah; Aghazadeh-Amiri, Mohammad

2015-01-01

To determine the agreement between intraocular pressure (IOP) measurements using an automated non-contact tonometer (NCT), Goldmann applanation tonometer (GAT), and the ocular response analyzer (ORA) in subjects with primary congenital glaucoma (PCG). Twenty-nine eyes of 17 PCG patients underwent IOP measurements using NCT, GAT and ORA. Variables obtained by the ORA were corneal-compensated IOP (IOPcc), Goldmann-correlated IOP (IOPg), corneal hysteresis (CH), and corneal resistance factor (CRF). A difference more than 1.5 mmHg for IOP was considered as clinically relevant. Mean age of the patients was 12 years. Mean IOP (±standard deviation, SD) was 15.3 ± 2.8 mmHg (GAT), 15.5 ± 6.0 (NCT), 19.2 ± 7.0 (IOPg), and 21.1 ± 7.9 (IOPcc); (P = 0.001). Except for NCT vs. GAT (P = 1.0), the average IOP difference between each pair of measurements was clinically relevant. The 95% limits of agreements were - 10.2 to 10.3 mmHg (NCT vs. GAT), -7.8 to 15.3 (IOPg vs. GAT), and - 8.1 to 19.0 (IOPcc vs. GAT). The differences in IOP measurements increased significantly with higher average IOP values (r = 0.715, P = 0.001, for NCT vs. GAT; r = 0.802, P < 0.001, for IOPg vs. GAT; and r = 0.806, P < 0.001, for IOPcc vs. GAT). CH showed a significant association with differences in IOP measurements only for IOPcc vs. GAT (r = 0.830, P < 0.001). Mean IOP obtained by NCT was not significantly different from that of GAT, but ORA measured IOPs were significantly higher than both other devices.

Clinical tonometric measurements comparing three non-contact tonometers.

Science.gov (United States)

Walby, M A; Augsburger, A; Polasky, M

1975-06-01

Three American Optical Non-contact Tonometers were used to compare readings against each other. The attempt was to determine if all three tonometers were measuring the same IOP over a wide range of pressures. The assumption in practice is that all Non-contact Tonometers are manufactured within tolerance that should allow the examiner to find that same IOP on a patient regardless of the Non-contact Tonometer used. A preliminary study found no significant difference between the instruments.

Intraocular pressure measurement by three different tonometers in primary congenital glaucoma

Directory of Open Access Journals (Sweden)

Athar Zareei

2015-01-01

Full Text Available Purpose: To determine the agreement between intraocular pressure (IOP measurements using an automated non-contact tonometer (NCT, Goldmann applanation tonometer (GAT, and the ocular response analyzer (ORA in subjects with primary congenital glaucoma (PCG. Methods: Twenty-nine eyes of 17 PCG patients underwent IOP measurements using NCT, GAT and ORA. Variables obtained by the ORA were corneal-compensated IOP (IOPcc, Goldmann-correlated IOP (IOPg, corneal hysteresis (CH, and corneal resistance factor (CRF. A difference more than 1.5 mmHg for IOP was considered as clinically relevant. Results: Mean age of the patients was 12 years. Mean IOP (±standard deviation, SD was 15.3 ± 2.8 mmHg (GAT, 15.5 ± 6.0 (NCT, 19.2 ± 7.0 (IOPg, and 21.1 ± 7.9 (IOPcc; (P = 0.001. Except for NCT vs. GAT (P = 1.0, the average IOP difference between each pair of measurements was clinically relevant. The 95% limits of agreements were − 10.2 to 10.3 mmHg (NCT vs. GAT, −7.8 to 15.3 (IOPg vs. GAT, and − 8.1 to 19.0 (IOPcc vs. GAT. The differences in IOP measurements increased significantly with higher average IOP values (r = 0.715, P = 0.001, for NCT vs. GAT; r = 0.802, P < 0.001, for IOPg vs. GAT; and r = 0.806, P < 0.001, for IOPcc vs. GAT. CH showed a significant association with differences in IOP measurements only for IOPcc vs. GAT (r = 0.830, P < 0.001. Conclusion: Mean IOP obtained by NCT was not significantly different from that of GAT, but ORA measured IOPs were significantly higher than both other devices.

The influence of central corneal thickness and age on intraocular pressure measured by pneumotonometry, non-contact tonometry, the Tono-Pen XL, and Goldmann applanation tonometry.

Science.gov (United States)

Tonnu, P-A; Ho, T; Newson, T; El Sheikh, A; Sharma, K; White, E; Bunce, C; Garway-Heath, D

2005-07-01

To evaluate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements made with the Goldmann applanation tonometer (GAT), Tono-Pen XL, ocular blood flow tonograph (OBF), and Canon TX-10 non-contact tonometer (NCT). CCT was recorded for either eye (randomly selected) of each of 105 untreated patients with ocular hypertension and glaucoma attending the glaucoma research unit at Moorfields Eye Hospital. For each of the selected eyes, IOP was measured with the GAT (two observers), Tono-Pen, OBF, and NCT in a randomised order. The relation of measured IOP and of inter-tonometer differences with CCT and subject age was explored by linear regression analysis. A significant association between measured IOP and CCT was found with each instrument. The change in measured IOP for a 10 mum increase in CCT was 0.28, 0.31, 0.38, and 0.46 for the GAT, Tono-Pen, OBF, and NCT, respectively (all p< or = 0.05). There was a significant association between the NCT/GAT differences and CCT, with a tendency of NCT to overestimate GAT in eyes with thicker corneas. There was a significant association between GAT/Tono-Pen and OBF/Tono-Pen differences and age, with a tendency of GAT and OBF to overestimate the Tono-Pen in eyes of older subjects. IOP measurement by all four methods is affected by CCT. The NCT is affected by CCT significantly more than the GAT. Subject age has a differential effect on the IOP measurements made by the GAT and OBF compared to the Tono-Pen.

Avaliação de um novo produto na desinfecção do tonômetro de aplanação de Goldmann The evaluation of a new product in the desinfection of the applanation tonometer

Directory of Open Access Journals (Sweden)

Nelson Maimone

2001-11-01

Full Text Available Objetivo: Avaliar a eficácia de um produto usado habitualmente para limpeza de lentes de contato (CompleteÒ: poliexametileno de biguanida (TrisChemTM, tiloxapol, trometamina e EDTA em solução isotônica estéril na desinfecção do cone do tonômetro de aplanação. Métodos: O cone permaneceu imerso na solução no período médio de 28 minutos. Foi utilizado um recipiente para limpeza de lentes de contato e um suporte de isopor. Ao final de cada dia, durante 22 dias, foram realizadas culturas para fungos e bactérias, exames diretos para fungos e bacterioscopia por Gram. Foi testado "in vitro" o poder bactericida e fungicida do produto para S. aureus ATCC#25923, E. coli ATCC#25922, P. aeruginosa ATCC#27853, C. albicans ATCC# 76615, A. niger ATCC#16404. Resultados: Nas culturas, nos exames diretos para fungos e nas bacterioscopias por Gram não foram identificados microrganismos. No estudo "in vitro", foram necessárias 48 horas para eliminação completa de todas cepas estudadas. Conclusão: Não foram encontradas bactérias e fungos em todos exames realizados da solução e recipiente. No entanto, os testes "in vitro" demonstraram que o tempo de imersão do cone na solução (média de 28 minutos é insuficiente para eliminação completa dos microrganismos, o que inviabiliza o uso desse produto na desinfecção do cone plástico do tonômetro de aplanação.Purpose: To evaluate the efficacy of a product which is normally used for cleaning of contact lenses (CompleteÒ: polyhexamethylene biguanide (Tris ChemTM, Tyloxapol, USP, Tromethamine, USP, and Edetate disodium, USP, in sterile isotonic solution in the disinfection of the cone of the applanation tonometer. Methods: The cone remained immersed in the solution for an average period of 28 minutes. A container for cleaning the contact lenses and a polystyrene support were used. At the end of each day, for 22 days, cultures for fungi and bacteria were carried out as well as direct

Intraocular pressure and ocular pulse amplitude using dynamic contour tonometry and contact lens tonometry

Directory of Open Access Journals (Sweden)

Grus Franz-H

2004-03-01

Full Text Available Abstract Background The new Ocular Dynamic Contour Tonometer (DCT, investigational device supplied by SMT (Swiss Microtechnology AG, Switzerland allows simultaneous recording of intraocular pressure (IOP and ocular pulse amplitude (OPA. It was the aim of this study to compare the IOP results of this new device with Goldmann tonometry. Furthermore, IOP and OPA measured with the new slitlamp-mounted DCT were compared to the IOP and OPA measured with the hand-held SmartLens®, a gonioscopic contact lens tonometer (ODC Ophthalmic Development Company AG, Switzerland. Methods Nineteen healthy subjects were included in this study. IOP was determined by three consecutive measurements with each of the DCT, SmartLens®, and Goldmann tonometer. Furthermore, OPA was measured three times consecutively by DCT and SmartLens®. Results No difference (P = 0.09 was found between the IOP values by means of DCT (mean: 16.6 mm Hg, median: 15.33 mm Hg, SD: +/- 4.04 mm Hg and Goldmann tonometry (mean: 16.17 mm Hg, median: 15.33 mm Hg, SD: +/- 4.03 mm Hg. The IOP values of SmartLens® (mean: 20.25 mm Hg, median: 19.00 mm Hg, SD: +/- 4.96 mm Hg were significantly higher (P = 0.0008 both from Goldmann tonometry and DCT. The OPA values of the DCT (mean: 3.08 mm Hg, SD: +/- 0.92 mm Hg were significantly lower (P = 0.0003 than those obtained by SmartLens® (mean: 3.92 mm Hg, SD: +/- 0.83 mm Hg. Conclusions DCT was equivalent to Goldmann applanation tonometry in measurement of IOP in a small group of normal subjects. In contrast, SmartLens® (contact lens tonometry gave IOP readings that were significantly higher compared with Goldmann applanation tonometer readings. Both devices, DCT and SmartLens® provide the measurement of OPA which could be helpful e.g. for the management of glaucoma.

Active noncontact tonometer for glaucoma detection

Science.gov (United States)

Han, Yanmei; Bryanston-Cross, Peter J.; Lee, Wing K. A.; Hero, Mark

2002-09-01

Glaucoma is an increasingly common cause of visual impairment, and in some cases causes blindness. The approach to develop a low cost and non-contact tonometer for the detection of glaucoma, to replace the Goldmann tonometer used worldwide, is presented in this paper. The new tonometer exploits the vibration property of the cornea - the resonance frequency of the cornea rises with increasing intra-ocular pressure (IOP). An audio frequency signal is used to vibrate the cornea of the eye, the vibration of the cornea is measured using a fibre optic lever probe, and then the IOP can be calculated from the detected resonance frequency of the cornea. The initial PC-version experiment system of the new tonometer has been demonstrated and preliminary testing has been performed, showing a suitable sensitivity in detecting the resonance frequency against the IOP using both the simulated-eye model and the pig's eye. The initial system has been improved to be suitable for greater than 15mm detecting distance, and the measurement of vibrations of human cornea in-vivo has been carried out. Work is now focusing on increasing the sensitivity of the fibre probe, and reducing the measuring time to less than 1 second.

[Experiences with the non-contact-tonometer (author's transl)].

Science.gov (United States)

Dittmar, P; Weinberg, M; Liegl, O

1975-07-01

The Non-Contact-Tonometer as developed by the American Optical Corporation, is in use superior to the traditional methods of intraocular-pressure measurements according to Schiötz and Goldmann: Without any manipulation on the eye the intra-ocular pressure can be measured rapidly and easily. Owing to the construction of the tonometer however measurements are only possible with smooth corneae. In addition to this the results of measurement with the NCT are not as exact as those of the traditional methods. Finally there is up to the present no possibility of standardising the new tonometer.

Femtosecond laser cutting of endothelial grafts: comparison of endothelial and epithelial applanation.

Science.gov (United States)

Bernard, Aurélien; He, Zhiguo; Gauthier, Anne Sophie; Trone, Marie Caroline; Baubeau, Emmanuel; Forest, Fabien; Dumollard, Jean Marc; Peocʼh, Michel; Thuret, Gilles; Gain, Philippe

2015-02-01

Stromal surface quality of endothelial lamellae cut for endothelial keratoplasty with a femtosecond laser (FSL) with epithelial applanation remains disappointing. Applanation of the endothelial side of the cornea, mounted inverted on an artificial chamber, has therefore been proposed to improve cut quality. We compared lamellar quality after FSL cutting using epithelial versus endothelial applanation. Lamellae were cut with an FSL from organ-cultured corneas. After randomization, 7 were cut with epithelial applanation and 7 with endothelial applanation. Lamellae of 50-, 75-, and 100-μm thickness were targeted. Thickness was measured by optical coherence tomography before and immediately after cutting. Viable endothelial cell density was quantified immediately after cutting using triple labeling with Hoechst/ethidium/calcein-AM coupled with image analysis with ImageJ. The stromal surface was evaluated by 9 masked observers using semiquantitative scoring of scanning electronic microscopy images. Histology of 2 samples was also analyzed before lamellar detachment. Precision (difference in target/actual thickness) and thickness regularity [coefficient of variation (CV) of 10 measurements] were significantly better with endothelial applanation (precision: 18 μm; range, 10-30; CV: 11%; range, 8-12) than with epithelial applanation (precision: 84 μm; range, 54-107; P = 0.002; CV: 24%; range, 13-47; P = 0.001). Endothelial applanation provided thinner lamellae. However, viable endothelial cell density was significantly lower after endothelial applanation (1183 cells/mm2; range, 787-1725 versus 1688 cells/mm2; range, 1288-2025; P = 0.018). FSL cutting of endothelial lamellae using endothelial applanation provides thinner more regular grafts with more predictable thickness than with conventional epithelial applanation but strongly reduces the pool of viable endothelial cells.

Accuracy and reliability of the Keeler Pulsair EasyEye non-contact tonometer.

Science.gov (United States)

Ogbuehi, Kelechi C; Almubrad, Turki M

2008-01-01

To evaluate the accuracy and reliability of the Keeler Pulsair EasyEye noncontact tonometer in a normotensive population. This masked prospective clinical study included 72 right eyes of 72 subjects. Two sets of intraocular pressure measurements were made 1 week apart. Intraocular pressure assessment with the Goldmann tonometer was always subsequent to that with the noncontact tonometer. Each method was assessed for within-session and test-retest repeatability and both methods were assessed for limits of agreement, twice. The level of significance for this study was 0.05. Both methods were repeatable within-sessions to within +/-2 mm Hg, and between sessions to within +/-3 mm Hg. Neither the within-session differences nor the between session differences differed significantly between the Goldmann tonometer and the Pulsair EasyEye noncontact tonometer. The mean differences (+/-SD) between both methods (0.1 +/- 1.6 mm Hg and 0.05 +/- 1.7 mm Hg, for the first and second sessions, respectively) were not statistically significant, but the intraocular pressure measured with the Pulsair EasyEye tonometer was consistently higher than that measured with the Goldmann tonometer. The Pulsair EasyEye noncontact tonometer is considered an accurate reliable method in the normotensive population studied but because of a systematic bias in a small number of subjects, it cannot be used interchangeably with the Goldmann tonometer.

IOP measurement in silicone oil tamponade eyes by Corvis ST tonometer, Goldmann applanation tonometry and non-contact tonometry.

Science.gov (United States)

Zhang, Yang; Zheng, Lin; Bian, Ailing; Zhou, Qi

2018-04-01

To compare the postoperative intraocular pressure (IOP) of eyes following pars plana vitrectomy (PPV) combined with intravitreal silicone oil (SO) tamponade by Corneal Visualization Scheimpflug Technology (CST), Goldmann applanation tonometry (GAT) and non-contact tonometry (NCT). Thirty-eight participants who had undergone PPV combined with SO tamponade to treat vitreoretinal diseases were enrolled. Postoperative IOP measurements were obtained using CST, NCT and GAT. Inter-device agreement was assessed by Bland-Altman analysis. The correlation coefficient was used to describe the potential postoperative factors affecting the postoperative IOP differences between each device. Bland-Altman analysis revealed the bias between CST and GAT, between CST and NCT, and between GAT and NCT to be -0.2, 2.1 and 2.4 mmHg, respectively. CST and GAT correlated well with each other. NCT values were lower than those of GAT and CST (all p contact method for measuring postoperative IOP in SO tamponade eyes.

Goldmann applanation tonometry over daily disposable contact lens: accuracy and safety of procedure.

Science.gov (United States)

Zeri, Fabrizio; Lupelli, Luigi; Formichella, Paolo; Masci, Carlo; Fletcher, Robert

2007-09-01

To study accuracy and safety, related to sensation (discomfort) and trauma, when using Goldmann applanation tonometry (GAT) on eyes wearing daily disposable soft contact lenses. The intra-ocular pressure (IOP) of 136 normal eyes of 68 subjects was measured by Goldmann tonometer. Measurements were made in one eye with a contact lens (hilafilcon A) without anaesthetic drops and then without the contact lens using one drop of 0.4% oxybuprocaine hydrochloride. Each contact lens used was identical as to back optic zone, back vertex power. Standard Goldmann procedure only was used for the fellow eye of each subject. Subjective sensation (discomfort) responses to both procedures were studied in a subgroup (66 eyes) using a scale of discomfort, from 1 (no sensation) to 5 (highest sensation). Epithelial staining after tonometry was evaluated for this subgroup. No significant differences were found for the IOP with and without contact lens (tcontact lens insertion, tonometry on contact lens and application of topical anaesthetic). Corneal epithelial staining following the standard tonometry procedure was significantly higher than following the procedure with a contact lens (pcontact lens is accurate, compared to the standard procedure and within the IOP's normal range studied here. Also using a contact lens results in less trauma whilst discomfort is similar.

Changes in intraocular pressure values measured with noncontact tonometer (NCT), ocular response analyzer (ORA) and corvis scheimpflug technology tonometer (CST) in the early phase after small incision lenticule extraction (SMILE).

Science.gov (United States)

Shen, Yang; Su, Xiangjian; Liu, Xiu; Miao, Huamao; Fang, Xuejun; Zhou, Xingtao

2016-11-18

Corneal biomechanical properties are always compromised after corneal refractive surgeries thus leading to underestimated intraocular pressure (IOP) that complicates the management of IOP. We investigated the changes in postoperative baseline of IOP values measured with noncontact tonometer (NCT), ocular response analyzer (ORA) and corvis scheimpflug technology (CST) in the early phase after small incision lenticule extraction (SMILE). Twenty-two eyes (-6.76 ± 1.39D) of 22 moderate and high myopes, (28.36 ± 7.14 years, 12 male and 10 female) were involved in this prospective study. IOP values were measured using a non-contact tomometer (NCT-IOP), an ocular response analyzer (corneal-compensated IOP, IOPcc and Goldmann-correlated IOP, IOPg) and a Corvis scheimpflug technology tonometer (CST-IOP) preoperatively, at 20 min and 24 h, postoperatively. Repeated measures analysis of variance (RM-ANOVA), Pearson's correlation analysis and multiple linear regression models (stepwise) were performed. Cut-off P values were 0.05. Except for IOPcc, NCT-IOP, IOPg, and CST-IOP values significantly decreased after SMILE procedure (All P values 0.05). Multiple linear regression models (stepwise) showed that the practical post-operative IOP value was the main predictor of the theoretical post-operative NCT-IOP, IOPcc and IOPg values (all P values <0.001). The postoperative applanation time 1 (AT1) value (B = 8.079, t = 4.866, P < 0.001), preoperative central corneal thickness (CCT) value (B = 0.035, t = 2.732, P = 0.014) and postoperative peak distance (PD) value (B = 0.515, t = 2.176, P = 0.043) were the main predictors of the theoretical post-operative CST-IOP value. IOP values are underestimated when assessed after SMILE by using NCT-IOP, IOPg and CST-IOP. The practical postoperative IOPcc value and theoretical post-operative CST-IOP value may be more preferable for IOP assessment in the early phase after SMILE. Current Controlled

Evaluation of monkey intraocular pressure by rebound tonometer

Science.gov (United States)

Yu, Wenhan; Cao, Guiqun; Qiu, Jinghua; Ma, Jia; Li, Ni; Yu, Man; Yan, Naihong; Chen, Lei; Pang, Iok-Hou

2009-01-01

Purpose To evaluate the usefulness of the TonoVet™ rebound tonometer in measuring intraocular pressure (IOP) of monkeys. Methods The accuracy of the TonoVet™ rebound tonometer was determined in cannulated eyes of anesthetized rhesus monkeys where IOP was controlled by adjusting the height of a connected perfusate reservoir. To assess the applicability of the equipment through in vivo studies, the diurnal fluctuation of IOP and effects of IOP-lowering compounds were evaluated in monkeys. Results IOP readings generated by the TonoVet™ tonometer correlated very well with the actual pressure in the cannulated monkey eye. The linear correlation had a slope of 0.922±0.014 (mean±SEM, n=4), a y-intercept of 3.04±0.61, and a correlation coefficient of r2=0.97. Using this method, diurnal IOP fluctuation of the rhesus monkey was demonstrated. The tonometer was also able to detect IOP changes induced by pharmacologically active compounds. A single topical ocular instillation (15 μg) of the rho kinase inhibitor, H1152, produced a 5–6 mmHg reduction (pmonkey eye. PMID:19898690

Effects of laser in situ keratomileusis (LASIK) on corneal biomechanical measurements with the Corvis ST tonometer.

Science.gov (United States)

Frings, Andreas; Linke, Stephan J; Bauer, Eva L; Druchkiv, Vasyl; Katz, Toam; Steinberg, Johannes

2015-01-01

This study was initiated to evaluate biomechanical changes using the Corvis ST tonometer (CST) on the cornea after laser in situ keratomileusis (LASIK). University Medical Center Hamburg-Eppendorf, Germany, and Care Vision Refractive Centers, Germany. Retrospective cohort study. This retrospective study included 37 eyes of 37 refractive patients. All CST measurements were performed 1 day before surgery and at the 1-month follow-up examination. The LASIK procedure included mechanical flap preparation using a Moria SBK microkeratome and an Allegretto excimer laser platform. Statistically significant differences were observed for mean first applanation length, mean first and second deflection lengths, mean first and second deflection amplitudes, radius of curvature, and peak distance. Significant positive correlations were found between the change (Δ) of radius of curvature and manifest refraction spherical equivalent (MRSE), ablation depth, and Δintraocular pressure as well as between AD and ΔHC-time. Each diopter of myopic correction in MRSE resulted in an increase in Δradius of curvature of 0.2 mm. Several CST parameters were statistically significantly altered by LASIK, thereby indicating that flap creation, ablation, or both, significantly change the ability of the cornea to absorb or dissipate energy.

The Pulsair-Keeler non-contact tonometer in self-tonometry: preliminary results.

Science.gov (United States)

Boles Carenini, B; Brogliatti, B; Tonetto, C; Renis, E

1992-09-01

The authors considered the possibility of using the Pulsair-Keeler non-contact tonometer in self-tonometry. For this reason, 45 patients have been trained to use the instrument and, after a reasonable trial period, were able to self-measure their IOP. The results have been compared to the tonometric values measured with Goldmann tonometer to evaluate statistically the limits and the dependability of this method of measurement. The results shows that self-tonometry with the Pulsair-Keeler tonometer can be used in monitoring glaucomatous patients at home.

Measurement of intraocular pressure using the NT-4000: a new non-contact tonometer equipped with pulse synchronous measurement function.

Science.gov (United States)

Yaoeda, Kiyoshi; Shirakashi, Motohiro; Fukushima, Atsushi; Funaki, Shigeo; Funaki, Haruko; Ofuchi, Nobutaka; Nakatsue, Tomoko; Abe, Haruki

2005-06-01

NT-4000 (Nidek Co. Ltd., Gamagori, Japan) is a new non-contact tonometer (NCT) equipped with pulse synchronous measurement function that can measure intraocular pressure (IOP) synchronized with the ocular pulse. The purpose of this study was to evaluate the usefulness of NT-4000 in normal subjects and in patients with glaucoma and ocular hypertension. This study included 175 eyes of 175 subjects. Firstly, the IOP was measured using NT-4000 without the pulse synchronous measurement function (NTn). Secondly, the IOP at peak, middle, and trough phases of the pulse signal were measured using NT-4000 with the pulse synchronous measurement function (NTp, NTm, NTt, respectively). Additionally, the IOP was measured with Goldmann applanation tonometer (GT). The coefficient of variation (CV) of three readings in the NCT measurements was used to evaluate the intra-session reproducibility. Statistical comparisons were performed using Wilcoxon signed rank test and one-way analysis of variance with Scheffe's test. Linear regression analysis was used to calculate correlation coefficients. P values less than 0.05 were accepted as statistically significant. The CV of NTn, NTp, NTm, and NTt were 6.4%, 5.5%, 4.9%, and 5.2%, respectively. The CV of NTp, NTm, and NTt were significantly smaller than that of NTn (P = 0.007, P < 0.001, P < 0.001, respectively). NTp was significantly higher than NTt (P = 0.038). GT was significantly correlated with NTn, NTp, NTm, and NTt (r = 0.898, P < 0.001; r = 0.912, P < 0.001; r = 0.908, P < 0.001; r = 0.900, P < 0.001, respectively). NT-4000 can detect the fluctuation of IOP associated with the ocular pulse.

A cross-sectional study to compare intraocular pressure measurement by sequential use of Goldman applanation tonometry, dynamic contour tonometry, ocular response analyzer, and Corvis ST

Directory of Open Access Journals (Sweden)

Sushma Tejwani

2015-01-01

Full Text Available Objective: To study the correlation and effect of sequential measurement of intraocular pressure (IOP with Goldmann applanation tonometer (GAT, ocular response analyzer (ORA, dynamic contour tonometer (DCT, and Corvis ST. Setting and Design: Observational cross-sectional series from the comprehensive clinic of a tertiary eye care center seen during December 2012. Methods: One hundred and twenty-five study eyes of 125 patients with normal IOP and biomechanical properties underwent IOP measurement on GAT, DCT, ORA, and Corvis ST; in four different sequences. Patients with high refractive errors, recent surgeries, glaucoma, and corneal disorders were excluded so as to rule out patients with evident altered corneal biomechanics. Statistical Analysis: Linear regression and Bland-Altman using MedCalc software. Results: Multivariate analysis of variance with repeated measures showed no influence of sequence of device use on IOP (P = 0.85. Linear regression r 2 between GAT and Corvis ST, Corvis ST and Goldmann-correlated IOP (IOPg, and DCT and Corvis ST were 0.37 (P = 0.675, 0.63 (P = 0.607, and 0.19 (P = 0.708, respectively. The Bland-Altman agreement of Corvis ST with GAT, corneal compensated IOP, and IOPg was 2 mmHg (−5.0 to + 10.3, −0.5 mmHg (−8.1 to 7.1, and 0.5 mmHg (−6.2 to 7.1, respectively. Intraclass correlation coefficient for repeatability ranged from 0.81 to 0.96. Conclusions: Correlation between Corvis ST and ORA was found to be good and not so with GAT. However, agreement between the devices was statistically insignificant, and no influence of sequence was observed.

Comparative study of intraocular pressure (IP in Bangladeshi individuals by contact and non contact technique

Directory of Open Access Journals (Sweden)

Sayed Abdul Wadud

2016-07-01

Full Text Available Background: Intraocular pressure (IOP is one of the most important parameters in the diagnosis and treatment of glaucoma. Glaucoma has been established as the second leading cause of blindness. The treatment of glaucoma focuses mainly on lowering intraocular pressure (IOP. The target IOP is often set to a level 20% to 30% of IOP reduction, and consequent large IOP reduction beyond 30% or even 40% in cases of advanced glaucoma The different methods of tonometery are: Goldman Applanation tonometery, Noncontact (air-puff tonometery, Perkins tonometery, Tonopen tonometery, Transpalpebral tonometery.Objective: To determine the frequency of accuracy of intraocular pressure (IOP measured by non-contact (air puff tonometer compared with Goldmann applanation tonometer.Methods: This was a non-interventional, cross sectional study conducted at a tertiary care centre of Dhaka, Bangladesh. consecutive subjects attending the BSMMU eye OPD were included in the study. IOP was measured by non-contact (air puff tonometer and a slit lamp mounted GAT in all the subjects. The study samples were selected by convenience sampling who presented for check-up in the Eye Department of community ophthalmology, Bangabandhu Sheikh Mujib Medical University, Dhaka. Bangladesh. Results:A total of 120 eyes in 60 patients were studied. The mean age of the patients was 41.60 year. study population consisted of 24 (40 % men and 36 (60 % women. The mean intraocular pressure was 13.52 &13.72 mmHg for GAT, and 16.64 & 17.44 mmHg for Air puff respectively. The range of measurements by GAT was from 10 to 23 mmHg and by Air puff was 12 to 28mmHg. The difference between IOP measured by two instruments were statistically significant (p=0.000.Conclusion: Airpuff tonometer is quick, a non-contact method to measure intraocular pressure and is useful for screening purposes and postoperative case but the measurements should be confirmed with Goldmann applanation tonometer for accurate labelling

Minimising the risk of prion transmission by contact tonometry.

Science.gov (United States)

Amin, S Z; Smith, L; Luthert, P J; Cheetham, M E; Buckley, R J

2003-11-01

The unknown prevalence of variant Creutzfeldt-Jakob disease (vCJD) in the UK population has led to fears of horizontal transmission through routine medical procedures. The potential risk of transmission via contact tonometry was examined. The total amount of protein carried over by tonometer tips after applanation of patients was assessed. Tonometer tips had an inherent ability to carry proteinaceous material. There was a large variability in the load carried over between individual patients. Rinsing tonometer tips in water reduced protein carryover. Wiping the tonometer tips also reduced carriage, though less dramatically. There is a small theoretical risk of transmission of vCJD by contact tonometry through reuse, but this should be reduced if the prisms are washed and wiped. In the light of these findings a protocol for the management of reusable tonometer prisms is recommended.

Non-contact tonometry in the postoperative eye.

OpenAIRE

Vernon, S A

1989-01-01

The Keeler Pulsair non-contact tonometer was compared with the Goldmann applanation tonometer in a series of 48 eyes after operation. A correlation coefficient of 0.92 (p less than 0.001) was found between the two instruments, with the Pulsair having a statistically significant tendency to overread the Goldmann slightly in this situation. The Pulsair was, however, shown to be effective in the identification of postoperative ocular hypertension with a high degree of sensitivity and specificity...

[Comparative study between the non-contact pneumotonometer Canon TX10 and the Goldmann tonometer].

Science.gov (United States)

Sánchez-Tocino, H; Bringas-Calvo, R; Iglesias-Cortiñas, D

2005-11-01

To study and contrast the measurement of intraocular pressure (IOP) with an air non-contact tonometer (Canon TX-10) with that obtained with the Goldmann tonometer. Intraocular pressure was measured in 649 subjects with both the pneumotonometer and the Goldmann tonometer. Statistically significant differences between the results obtained by both tonometers and the influence of variables including age, corneal thickness, and corneal curvature were studied. The mean age of the study population was 48.5 years, standard deviation (SD) 7.6 years, with a range of 22-68 years. The mean IOP was 15.4, SD 2.7 mm Hg, (range 8-25) with the Goldmann tonometer and 15.6, SD 2.9 mm Hg (range 8-29) with the pneumotonometer. There was a statistically significant difference between the measurements using the air pneumotonometer and the Goldmann tonometer (ptonometers was 0.24, SD 2 mm Hg. Seventy-five percent of measurements were in the range of +/-1, 85% in +/-2, and 95% in the Bland and Altman's interval of 4.42, -3.94. These differences were more significant for higher values of IOP, in thicker corneas and in corneas with greater curvature. A correlation between IOP and age was not found (p=0.247). The pneumotonometer is a useful and reliable instrument for measuring the IOP providing there is additional checking in cases with borderline values of IOP, or excessive corneal thickness and/or curvature.

Intraocular pressure asymmetry is not a clinically-significant feature when using the PULSAIR non-contact tonometer.

Science.gov (United States)

Pointer, J S

1997-11-01

This report describes the results of a retrospective analysis of intraocular pressure (i.o.p.) values recorded from the right (R) and left (L) eyes of middle-aged and elderly at-risk but assumed non-glaucomatous subjects. The tensions had been measured using the Keeler PULSAIR non-contact tonometer (NCT) in the course of routine optometric practice when individuals attended for a sight test. These bilateral IOP data were collated on the basis of each subject's gender, (male/female), age (40-59 years/60+ years) and the time of the tonometry assessment (a.m./p.m.). Wherever possible material was equi-partitioned across these three bipartite variables producing balanced data groupings. Pair-wise testing of R versus L absolute values of pneumo-applanation pressures across any of the balanced data groupings failed to reveal a statistically-significant difference between the paired IOP distributions. There was a consistent but small relative IOP asymmetry (L > R) in these data. Further analysis indicated that this asymmetry only attained borderline statistical significance with respect to subject's age: neither gender nor the time of assessment were statistically significant features, and there were no statistically-significant interactions between any of the three variables. In conclusion, provided that the manufacturer's operating instructions are adhered to, IOP asymmetry is not a clinically-significant feature when using the PULSAIR NCT on a clinical population at risk of developing glaucoma.

Intraocular pressure measurement in patients with previous LASIK surgery using pressure phosphene tonometer.

Science.gov (United States)

Cheng, Arthur C K; Leung, Dexter Y L; Cheung, Eva Y Y; Fan, Dorothy S P; Law, Ricky W K; Lam, Dennis S C

2005-04-01

To compare intraocular pressure (IOP) assessment in post-LASIK patients using non-contact tonometry, pressure phosphene tonometry and applanation tonometry. Sixty-two consecutive LASIK patients were analysed preoperatively and postoperatively with non-contact, pressure phosphene and applanation tonometry. Comparisons among these values were assessed with paired sample Student t-test, Pearson's correlation test and Bland-Altman plotting. There was no significant difference for preoperative IOP measurement between non-contact, pressure phosphene and applanation tonometry. The mean +/-SD difference between the preoperative non-contact tonometry and postoperative pressure phosphene tonometry IOP measurements was 0.80 +/- 2.77 mmHg (P contact tonometry significantly underestimated IOP measurement by 9.96 +/- 2.25 mmHg (P < 0.001). Pressure phosphene tonometry may provide an alternative method for the assessment of IOP in post-LASIK patients.

Intraocular pressure asymmetry-Topcon Computerised Tonometer CT-20.

Science.gov (United States)

Ntim-Amponsah, C T

1997-01-01

The Topcon Computerised Tonometer CT-20, a non-contact tonometer (NCT), was used to measure intraocular pressure (IOP) in mmHg in 1,226 subjects above the age of 30 years with no ocular pathology. The mean IOP was 14.41 mmHg and the standard deviation 3.43. The mean IOP far was higher in female (14.60) than male (14.22). This gender difference in the mean IOP was significant; t stat = 2.69, P < 0.5. Right IOP exceeded left IOP and this was highly significant in both male (t stat 4.03) and female (t stat 5.64) p < 0.01. This IOP asymmetry approximates a normal distribution. The mean of the differences (right-left IOP) and standard deviation for all subjects were 0.57 and 2.26 respectively. The range for the differences was- 10 to 10 mmHg. Asymmetry was greater in females than males (t stat = 2.05, p < 0.05). Knowledge of these statistics will help in decisions concerning glaucoma screening with NCT.

Quantitative assessment of responses of the eyeball based on data from the Corvis tonometer.

Science.gov (United States)

Koprowski, Robert; Wilczyński, Sławomir; Nowinska, Anna; Lyssek-Boron, Anita; Teper, Sławomir; Wylegala, Edward; Wróbel, Zygmunt

2015-03-01

The "air-puff" tonometers, include the Corvis, are a type of device for measuring intraocular pressure and biomechanics parameters. The paper attempts to analyse this response and its relationship with other parameters measured in the Corvis tonometer. A number of 13,400 2D images were acquired from the Corvis device and analysed (32 healthy and 16 ill people). A new method has been proposed for the analysis of responses of the eyeball based on morphological transformations and contextual operations. The proposed algorithm enables to determine responses of the eyeball to an air puff coming from the Corvis tonometer. Additionally, responses of the eyeball have been linked to some selected features of corneal deformation. The results include, among others: (1) distinguishability between the left and right eye with an error of 7%; (2) the correlation between the area under the curve in corneal deformation and the response of the eyeball -0.26; (3) the correlation between the highest concavity time and the maximum deformation amplitude of 0.4. All these features are obtained fully automatically and repetitively at a time of 3.8s per patient (Core i7 10GB RAM). It is possible to measure additional parameters of the eye deformation which are not available in the original software of the Corvis tonometer. The use of the proposed methods of image analysis and processing provides results directly from the eye response measurement when measuring intraocular pressure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Irregularity of the posterior corneal surface during applanation using a curved femtosecond laser interface and microkeratome cutting head.

Science.gov (United States)

Vetter, Jan M; Holtz, Carsten; Vossmerbaeumer, Urs; Pfeiffer, Norbert

2012-03-01

To evaluate the irregularity of the posterior corneal surface and intrastromal dissection during the preparation of donor tissue for Descemet stripping automated endothelial keratoplasty (DSAEK) using a curved interface femtosecond laser and microkeratome. Sixteen human donor corneas unsuitable for transplantation were divided into two groups: a femtosecond (FS) laser group (n=7) using the VisuMax femtosecond laser (Carl Zeiss Meditec) and a microkeratome group (n=9) using the Amadeus II microkeratome (Ziemer Ophthalmic Group). The corneas were fixed on artificial anterior chambers. Horizontal cross-sections were obtained using spectral-domain optical coherence tomography prior to applanation, during applanation, as well as during and after intrastromal dissection at 450-μm corneal depth. The posterior surface and the dissection line were evaluated for irregularity by fitting a second-order polynomial curve using regression analysis and obtaining the root-mean-square error (RMSE). Groups were compared using analysis of variance. The RMSE of the posterior surface prior to applanation was 9.7 ± 3.1 μm in the FS laser group and 10.2 ± 2.3 μm in the microkeratome group. The RMSE increased to 50.7 ± 9.4 μm and 20.9 ± 6.1 μm during applanation and decreased again to 10.6 ± 1.4 μm and 8.1 ± 1.8 μm after applanation in the FS laser and microkeratome groups, respectively. The RMSE of the intrastromal cut was 19.5 ± 5.7 μm in the FS laser group and 7.7 ± 3.0 μm in the microkeratome group (P<.001). Our results show significantly greater irregularity with the curved interface femtosecond laser-assisted cleavage compared to microkeratome-assisted corneal dissection, possibly due to applanation-derived deformation of the posterior cornea. Copyright 2012, SLACK Incorporated.

Simultaneous measurement of eye stiffness and contact area for living human eyes.

Science.gov (United States)

Kurita, Yuichi; Iida, Yoshichika; Kaneko, Makoto; Mishima, Hiromu K; Katakura, Seiki; Kiuchi, Yoshiaki

2007-01-01

Goldmann applanation tonometry is commonly used for measuring IOP (IntraOcular Pressure) to diagnose glaucoma. However, the measured IOP by the applanation tonometry is valid only under the assumption that all the subjects have the same structural eye stiffness. Abnormal eye stiffness makes abnormal corneal deformation and thus the current applanation tonometer misestimates the IOP. This study challenges to measure the eye stiffness in vivo with a non-invasive approach for detecting the abnormal deformation. The deformation of the cornea and the contact area between the probe and the cornea are simultaneously captured by cameras during the experiment. Experimental results show that some subjects have different relationship among the force, the displacement and the contact area even with same IOP. The proposed eye stiffness measurement can help detecting the abnormal deformation and the eyes with misestimated IOP.

Clinical evaluation of the Keeler Pulsair 3000 non-contact tonometer.

Science.gov (United States)

Lawson-Kopp, Wendy; DeJong, Amy; Yudcovitch, Lorne; Williams, Salisa; Kohl, Paul; Yolton, Robert L

2002-02-01

The Keeler Pulsair 3000 is a recently introduced non-contact tonometer that is especially useful for children and those for whom sitting at a slit-lamp or table-mounted unit would be difficult. In this project, intraocular pressures (IOPs) measured by Keeler Pulsair 3000 and Goldmann tonometers were compared to assess validity and reliability of the Pulsair 3000 data. Two Pulsair 3000 IOPs (each the mean of four individual air-puff readings) and two Goldmann IOPs were measured for each eye of 113 subjects. Subjects were also asked which measurement technique they preferred. IOPs ranged from 9 to 28 mmHg. Correlations between the two Goldmann IOPs measured for the right and left eyes were 0.98 and 0.97, respectively. These values are higher than correlations between Pulsair and Goldmann measurements (0.86 to 0.91). Pulsair 3000 IOPs were slightly above Goldmann values for pressures of less than 15 mmHg and slightly below for IOPs greater than 15 mmHg. Extrapolation to a Goldmann IOP of 30 mmHg suggests the Pulsair 3000 would read about 6% (1.7 mmHg) too low at this IOP. Eight eyes (7%) had differences between Pulsair 3000 and Goldmann IOP readings of 5.0 mmHg or more. Single outlier pressures accounted for these differences in three out of the eight eyes. In the range of 10 to 24 mmHg, the Pulsair 3000 tonometer produced IOP readings that corresponded well with Goldmann values for most eyes and was preferred by the majority of subjects who indicated a preference. The Pulsair 3000 is relatively easy to use by technicians and has numerous special applications in optometric practice (e.g. measuring IOPs for pediatric patients and those with compromised corneas).

Dynamic contour tonometry and goldman applanation tonometry in eyes with keratoconus Tonometria de contorno dinâmico e tonometria de aplanação de goldman em olhos com ceratocone

Directory of Open Access Journals (Sweden)

Jackson Barreto Jr

2006-01-01

Full Text Available PURPOSE: The dynamic contour tonometer is a nonapplanation contact tonometer designed to be largely independent of the structural properties of the cornea. Theoretically, it may measure intraocular pressure most accurately in abnormally thinner corneas. This study compares intraocular pressure measurements by dynamic contour tonometry with Goldman applanation tonometry in eyes with normal corneas and eyes with advanced keratoconus. METHODS: A comparative case series. Subjects underwent intraocular pressure measurements by dynamic contour tonometry, Goldman applanation tonometry, ultrasonic pachymetry, and slit scanning topography. Exclusion criteria: any ocular pathology other than keratoconus, previous corneal or refractive surgery, stromal scarring due to acute hydrops, or any other corneal opacities. RESULTS: Ten patients with keratoconus were included in Group A, and 12 normal patients composed Group B according to the pre-established criteria. The mean Goldman tonometry measurement in group A was 10.3 ± 1.8 mm Hg and group B was 14.3 ± 0.75 mm Hg. (P = 0.024. In group A, the mean measurement with the dynamic contour tonometer was 14.6 ± 2.09 mm Hg, and in group B, it was 17.4 ± 3.1 mm Hg (P = 0.026. The difference between both methods of measurement in group A was statistically significant (P OBJETIVO: O tonômetro de contorno dinâmico é um aparelho de contato e não-aplanação projetado para ser independente das propriedades estruturais da córnea. Teoricamente, ele mede de forma mais precisa a pressão intra-ocular em córneas muito finas. Este estudo compara as medidas de pressão intra-ocular pelo tonômetro de contorno dinâmico com a tonometria de aplanação de Goldman em olhos normais e em olhos com ceratocone avançado. MÉTODOS: uma série comparativa de casos. Pacientes foram submetidos às medidas de pressão intra-ocular por ambos os métodos mencionados, paquimetria ultrassônica e topografia corneana de varredura. Crit

Evaluation of intraocular pressure according to corneal thickness before and after excimer laser corneal ablation for myopia.

Science.gov (United States)

Hamed-Azzam, Shirin; Briscoe, Daniel; Tomkins, Oren; Shehedeh-Mashor, Raneen; Garzozi, Hanna

2013-08-01

Intraocular pressure is affected by corneal thickness and biomechanics. Following ablative corneal refractive surgery, corneal structural changes occur. The purpose of the study is to determine the relationship between the mean central corneal thickness (CCT) and the change in intraocular pressure measurements following various corneal ablation techniques, using different measurement methods. Two hundred myopic eyes undergoing laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) were enrolled into a prospective, non-randomized study. Corneal parameters examined included full ocular examination, measurement of CCT, corneal topography, corneal curvature and ocular refractivity. Intraocular pressure measurements were obtained using three different instruments-non-contact tonometer, Goldmann applanation tonometer and TonoPen XL (TonoPen-Central and TonoPen-Peripheral). All measurements were performed pre-operatively and 4 months post-operatively. Post-operative intraocular pressure was significantly lower than pre-operative values, with all instruments (p value tonometer and non-contact tonometer (p value < 0.001, ANOVA). Intraocular pressure readings are significantly reduced following corneal ablation surgery. We determined in our myopic patient cohort that the TonoPen XL intraocular pressure measurement method is the least affected following PRK and LASIK as compared to other techniques.

Intraocular pressure measurements after conductive keratoplasty.

Science.gov (United States)

Kymionis, George D; Naoumidi, Tatiana L; Aslanides, Ioannis M; Kumar, Vinod; Astyrakakis, Nikolaos I; Tsilimbaris, Miltiadis; Pallikaris, Ioannis G

2005-01-01

To determine the possible impact of conductive keratoplasty (CK) on intraocular pressure (IOP) measurements. A prospective, single-center, noncomparative interventional case series was performed. Baseline and postoperative IOPs were measured by Goldmann applanation tonometry in 32 eyes of 18 patients who underwent CK for hyperopia correction. Mean follow-up was 11.9 months (range: 8 to 18 months). After CK, a statistically significant decrease in the measured IOP was observed (before CK: 14.22+/-1.64 vs after CK: 12.66+/-2.21, P<.001). The change in IOP readings postoperatively was not correlated with age, sex, keratometric readings, or attempted correction. Despite the limitations due to the small number of patients enrolled in this study, the applanation tonometer appears to underestimate the true IOP after CK.

[Effect of intraocular pressure measurement through therapeutic soft contact lenses by noncontact tonometer].

Science.gov (United States)

Sugimoto-Takeuchi, R; Yamamoto, R; Kuwayama, Y; Kinoshita, S

1991-09-01

The measurement of intraocular pressure (IOP) was compared with and without soft contact lenses by a non-contact tonometer. The soft contact lenses examined were Plano-T and Plano-B4 therapeutic contact lenses and Breath-O refractive lens. Twenty-nine eyes of 18 patients with an IOP ranging from 9 to 48mmHg were studied. The measurements of IOP were 19.7 +/- 8.6mmHg with Plano-T and 18.9 +/- 9.2mmHg with Plano-B4. Both numbers were not statistically different, when compared with controls (19.3 +/- 9.8mmHg without lens). There was, however, a significant difference significant difference with (44.7 +/- 10.7mmHg) and without the Breath-O (p less than 0.01). The results suggest that accurate IOP measurements can be obtained through therapeutic soft contact lens by a non-contact tonometer.

Reliability of the non-contact tono-pachymeter Tonopachy NT-530P in healthy eyes.

Science.gov (United States)

García-Resúa, Carlos; Pena-Verdeal, Hugo; Miñones, Mercedes; Giraldez, M Jesus; Yebra-Pimentel, Eva

2013-05-01

Non-contact Tonopachy NT-530P (Nidek Co., LTD) provides intraocular pressure (IOP) and central corneal thickness (CCT) measurements. This study assesses the reliability and repeatability of its IOP measurements in young healthy adult subjects. IOP was determined in the right eye of 64 healthy patients using Tonopachy followed by the Canon TX-10 non-contact and Goldmann applanation (GAT) tonometers. Tonopachy IOP measurements were corrected (Tonopachy-C) or not (Tonopachy-NC) by the instrument for central corneal thickness. Central corneal thickness measurements provided by Tonopachy were also used to correlate (Pearson's coefficient) central corneal thickness with the GAT and Canon TX-10 IOPs. Repeatability of Tonopachy and GAT was assessed in the right eye of 31 subjects in two separate sessions one week apart. Differences between pairs of instruments and between sessions were determined using Bland-Altman plots. The coefficient of repeatability was calculated as the 95% limits of agreement (LoA) of differences between the two sessions. Tonopachy-NC, Tonopachy-C, Canon TX-10 and the Goldmann tonometers showed a mean IOP of 14.62, 15.64, 15.02 and 14.68 mmHg, respectively. Tonopachy-NC and Canon TX-10 readings did not differ significantly from the Goldmann (p > 0.05), with close agreement with both tonometers (GAT versus Tonopachy-NC: -3.84 to 3.96 mmHg; Goldmann versus Canon TX-10: -4.75 to 4.07 mmHg). Tonopachy-C readings differed significantly from Goldmann (mean difference -0.96 mmHg, p = 0.001, LoA from -5.09 to 3.17). Coefficients of repeatability were ± 3.70, ± 3.14 and ± 3.33 mmHg for GAT, Tonopachy-NC and Tonopachy-C, respectively. Central corneal thickness measured with Tonopachy was 530.42 ± 34.96 μm. There was a significant correlation between central corneal thickness and IOP for all tonometers except Tonopachy-C. Reasonable agreement was observed between the Goldmann and Tonopachy. This instrument provides reliable and repeatable IOP

Handheld juggernaut.

Science.gov (United States)

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.

Evaluation of a novel Scheimpflug-based non-contact tonometer in healthy subjects and patients with ocular hypertension and glaucoma.

Science.gov (United States)

Reznicek, Lukas; Muth, Daniel; Kampik, Anselm; Neubauer, Aljoscha S; Hirneiss, Christoph

2013-11-01

To evaluate the agreement of intraocular pressure (IOP) and central corneal thickness (CCT) measurements obtained with the non-contact tonometer Corvis Scheimpflug Technology (Corvis ST, OCULUS, Wetzlar, Germany) versus Goldmann applanation tonometry (GAT) and ultrasound-based corneal pachymetry (US-CCT). Eye healthy participants, patients with ocular hypertension (OHT) and patients with open-angle glaucoma were included in this prospective study. In each participant, GAT, US-CCT and measurements with Corvis ST were obtained (Corvis-IOP and Corvis-CCT). Accuracy and repeatability were tested by correlation and regression analyses, Bland-Altman plots and assessment of intraclass correlation coefficients. A consecutive series of 188 right study eyes of 188 participants (142 eyes with glaucoma, 10 eyes with OHT and 36 control eyes) were included in this prospective study. The mean GAT of all included was 14.5±4.8 mm Hg compared with mean Corvis-IOP of 15.4±5.6 mm Hg (Spearman's r=0.75, p<0.0001). Mean US-CCT was 544.56±40.0 µm compared with Corvis-CCT of 545.2±46.5 µm (Pearson's r=0.78, p<0.0001). Bland-Altman plots of all included eyes as well as subgroup analyses revealed good agreement of the IOP and CCT measurement techniques. High intraclass correlation coefficient values in 17 patients with repeated measurements revealed very good repeatability (0.942 and 0.937 for Corvis-IOP and Corvis-CCT, respectively). Corvis-IOP but not GAT showed a trend of dependence on CCT. Obtaining CCT and measuring IOP with the Corvis ST reveals very good repeatability and good accuracy in healthy subjects and patients with OHT and glaucoma when compared with standardised US pachymetry or GAT.

Comparison of current tonometry techniques in measurement of intraocular pressure.

Science.gov (United States)

Kouchaki, Behrooz; Hashemi, Hassan; Yekta, Abbasali; Khabazkhoob, Mehdi

2017-06-01

To compare four tonometry techniques: Goldmann applanation tonometer (GAT), Dynamic contour tonometer (DCT), Non-contact tonometer (NCT), and Ocular Response Analyzer (ORA) in the measurement of intraocular pressure (IOP) and the impact of some corneal biomechanical factors on their performance. In this cross-sectional study, volunteers with normal ophthalmic examination and no history of eye surgery (except for uncomplicated cataract surgery) or trauma were selected. Twenty-five subjects were male, and 21 were female. The mean age was 48 ± 19.2 years. Anterior segment parameters were measured with Scheimpflug imaging. IOP was measured with GAT, DCT, NCT, and ORA in random order. A 95% limit of agreement of IOPs was analyzed. The impact of different parameters on the measured IOP with each device was evaluated by regression analysis. The average IOP measured with GAT, DCT, NCT, and ORA was 16.4 ± 3.5, 18.1 ± 3.4, 16.2 ± 3.9, and 17.3 ± 3.4 mmHg, respectively. The difference of IOP measured with NCT and GAT was not significant ( P  = 0.382). Intraocular pressure was significantly different between GAT with DCT and IOP CC ( P  tonometers.

[IOP measurement through frequent-replacement soft contact lenses].

Science.gov (United States)

Touboul, J

2008-07-01

Intraocular pressure (IOP) can be measured through soft contact lenses with an air-puff tonometer. These measurements seemed accurate for low-power negative lenses. For positive soft contact lenses, IOP is overestimated. The measurement of IOP through a soft contact lens is acceptable in clinical practice only for glaucoma screening. In glaucomatous patients or patients with ocular hypertension, IOP measurements should be performed without a contact lens. The main technique for IOP measurement remains Goldmann applanation tonometry.

A comparative study of central corneal thickness (CCT) and intraocular pressure (IOP) in University of KwaZulu-Natal students of Black and Indian ethnicity*

OpenAIRE

Z. Sardiwalla; D. Moodley; T. Ndawonde; A. Madikizela; N. Ngobese; N. Thobela

2012-01-01

Thisstudy compared central corneal thickness (CCT) and intraocular pressure (IOP) of Black and Indian students from the University of Kwa-Zulu-Natal. Two hundred (100 Black and 100 Indi- an) participants of both genders aged 18-25 years (mean and standard deviation; 20.1±1.6 years) participated in this study. CCT and IOP were measured for the right eye of each participant using a Tono-Pachymeter (NT530P) and a Goldmann applanation tonometer (GAT) respectively. Data was analyzed with descr...

Assessment of corneal biomechanical parameters in myopes and emmetropes using the Corvis ST.

Science.gov (United States)

Lee, Rachel; Chang, Robert T; Wong, Ian Y H; Lai, Jimmy S M; Lee, Jacky W Y; Singh, Kuldev

2016-03-01

Prior studies have demonstrated conflicting results regarding the relationship between corneal biomechanical properties and refractive error. Thus, the purpose of this study was to compare the corneal biomechanical parameters of myopes and emmetropes. Ninety-four subjects with varying degrees of myopia (aged 29 to 74 years, spherical equivalent [SE] -0.5 to -17.5 D) and 25 emmetropes (aged 19 to 75 years, SE: -0.5 to +0.5 D) presenting at the Queen Mary Hospital, Hong Kong were recruited sequentially for this prospective study. All patients were phakic with no history of coexisting ocular disease. The corneal biomechanical parameters of the right eye of each subject were analysed using the Corvis ST non-contact tonometer. Intraocular pressure (IOP) was measured using both the Corvis ST and the Topcon Non-Contact Tonometer CT-80. Refractive error was measured by non-cycloplegic subjective and objective refractometry. High myopes (SE greater than -6.00 D) demonstrated greater mean outward applanation velocities (p < 0.001) and peak distance measurements (p = 0.009) compared to both low to moderate myopes (SE -0.50 to -6.00 D) and emmetropes. Both outward applanation velocity and peak distance were moderately correlated with refractive error (p ≤ 0.001), strongly correlated with IOP and weakly correlated with central corneal thickness. There were no statistically significant differences in age, IOP or central corneal thickness among emmetropes, low to moderate myopes or high myopes. Within this study of Chinese subjects, high myopes demonstrate greater corneal mean outward applanation velocity on Corvis ST testing, than emmetropes. In particular, those with high myopia (SE greater than -6.00 D) show a distinct corneal biomechanical profile relative to those with either emmetropia or low to moderate myopia using the Corvis ST. © 2016 Optometry Australia.

Comparison of Corneal Deformation Parameters in Keratoconic and Normal Eyes Using a Non-contact Tonometer With a Dynamic Ultra-High-Speed Scheimpflug Camera.

Science.gov (United States)

Mercer, Ryan N; Waring, George O; Roberts, Cynthia J; Jhanji, Vishal; Wang, Yumeng; Filho, Joao S; Hemings, Richard A; Rocha, Karolinne M

2017-09-01

To evaluate and compare biomechanical properties in normal and keratoconic eyes using a dynamic ultra-high-speed Scheimpflug camera equipped with a non-contact tonometer (Corvis ST; Oculus Optikgeräte GmbH, Wetzlar, Germany). This retrospective study evaluated 89 eyes (47 normal, 42 keratoconic) and a validation arm of 72 eyes (33 normal, 39 keratoconic) using the Corvis ST. A diagnosis of keratoconus was established by clinical findings confirmed by topography and tomography. Dynamic corneal response parameters collected by the Corvis ST (A1 velocity, deformation amplitude [DA], DA Ratio Max 1mm, and Max Inverse Radius) and a stiffness parameter at first applanation (SP-A1) were incorporated into a novel logistic regression equation (DCR index). Area under the receiver operating curve (AUC) was used to assess the sensitivity and specificity of the DCR index. DA, DA Ratio Max 1mm, Max Inverse Radius, and SP-A1 were each found to be statistically significantly different between normal and keratoconic eyes (Mann-Whitney test [independent samples]; P = .0077, < .0001, < .0001, and < .0001, respectively; significance level: P < .05). DCR index demonstrated high sensitivity, specificity, and overall correct detection rate (92.9%, 95.7%, and 94.4%, respectively; AUC = 98.5). The sensitivity and overall correct detection rate improved when eyes with Topographical Keratoconus Classification grades (TKC) greater than 0 were reevaluated (from 92.9% to 96.6% and from 94.4% to 96.1%, respectively). Combining multiple biomechanical parameters (A1 velocity, DA, DA Ratio Max 1mm, Max Inverse Radius, and SP-A1) into a logistic regression equation allows for high sensitivity and specificity for distinguishing keratoconic from normal eyes. [J Refract Surg. 2017;33(9):625-631.]. Copyright 2017, SLACK Incorporated.

Hand-held medical robots.

Science.gov (United States)

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.

Applanation optical coherence elastography: noncontact measurement of intraocular pressure, corneal biomechanical properties, and corneal geometry with a single instrument

Science.gov (United States)

Singh, Manmohan; Han, Zhaolong; Nair, Achuth; Schill, Alexander; Twa, Michael D.; Larin, Kirill V.

2017-02-01

Current clinical tools provide critical information about ocular health such as intraocular pressure (IOP). However, they lack the ability to quantify tissue material properties, which are potent markers for ocular tissue health and integrity. We describe a single instrument to measure the eye-globe IOP, quantify corneal biomechanical properties, and measure corneal geometry with a technique termed applanation optical coherence elastography (Appl-OCE). An ultrafast OCT system enabled visualization of corneal dynamics during noncontact applanation tonometry and direct measurement of micro air-pulse induced elastic wave propagation. Our preliminary results show that the proposed Appl-OCE system can be used to quantify IOP, corneal biomechanical properties, and corneal geometry, which builds a solid foundation for a unique device that can provide a more complete picture of ocular health.

The Effect of Various Contact Lenses on Intraocular Pressure Measurement by Goldman Tonometer

Directory of Open Access Journals (Sweden)

Monireh Mahjoob

2014-06-01

Full Text Available Background: Today, contact lenses have extensive usages. Contact lens places on cornea, so it may induce variation on cornea and these variations can influence the measurement of intraocular pressure (IOP by Goldman tonometer. The aim of this research was to study the effect of various contact lenses on measurement of intraocular pressure by Goldman tonometer. Materials and Methods: In this study, 80 subjects aged 18-25 were selected randomly among patients of Al-Zahra ophthalmology center. None of them has any eye pathological problems. Before wearing the lens, intraocular pressure was measured, and then patients were divided into two groups of soft and hard contact lenses. Soft and hard contact lenses were placed on the eye for two hours, and the intraocular pressure was measured again. Results: The mean of IOP before wearing contact lenses and two hours later was 15.96 mmHg and 13.93, s respectively. Paired test showed a significant difference between IOP before and after wearing contact lenses (p=0.001.There was no significant differences in mean of intraocular pressure decline before and after placing the contact lens in both soft and hard lenses. Conclusion: According to this study, the intraocular pressure decreases after wearing contact lenses (CL. This decline may be due to variation in properties of cornea after wearing CL that can also affect IOP measurement.

A clinical evaluation of the non-contact tonometer.

Science.gov (United States)

Wittenberg, S

1977-02-01

Paired non-contact tonometer readings were taken on patients at the Boston City Hospital Eye Clinic before and after routine vision care that included Goldmann tonometry. The variability of NCT readings was determined and comparisons made between readings obtained with the NCT and Goldmann instruments. The regression equation relating the pre-Goldmann NCT findings (N1), to the Goldmann (G), was N1 = 1.01G + 1.97; and the equation relating the post-Goldmann NCT findings (N2), to the Goldman was N2 = .94G + 1.70. The N1 mean was 2.06 mm. higher than the mean G, while the N2 mean was .58 mm. higher than the mean G. The correlation coefficients and standard deviation of the differences for the two comparisons were, .88, 3.91, and .93, 3.07, respectively. The Goldmann findings therefore were seen to agree more closely with the NCT findings taken after them. The linear regression and correlation coefficients between the NCT and the Goldmann were generally in good agreement with those of prior studies, although the standard deviations of the differences between findings were larger in this study. This result is not surprising since no attempt was made to train Goldmann operators to criterion or to limit variability induced by differing observer criteria or by the use of only one Goldmann operator. The operators of the Goldmann tonometer had varying degrees of training as residents in ophthalmology. Interestingly, the agreement between pre-Goldmann NCT and post-Goldmann NCT findings was not good. This suggested that the taking of the Goldmann findings themselves may have had a significant effect on the tonometric readings and that the considerable time that frequently took place between the two sets of NCT readings could have affected the value. The standard deviation of the differences between pre- and post-Goldmann readings on the same patient was 3.27 as compared to that for paired readings which was 2.28. The data also showed a much better agreement between the NCT and

Tonometría Goldmann versus tonometría de Pascal en pacientes poscirugía refractiva con LASIK Results of Goldman tonometry vs Pascal tonometry in patients after the refractive surgery with LASIK

Directory of Open Access Journals (Sweden)

Ileana González Silverio

2009-06-01

Full Text Available OBJETIVO: Comparar las cifras de presión intraocular obtenidas mediante el tonómetro de aplanación de Goldmann y el tonómetro de contorno dinámico de Pascal, así como la variación del espesor corneal central, antes y después de la cirugía refractiva con LASIK y así establecer la relación entre los dos tonómetros. MÉTODOS: Se estudiaron 74 pacientes (140 ojos, mayores de 21 años, con miopía estable (de -1 dioptrías a -10 dioptrías, defecto cilíndrico inferior a -3 dioptrías y espesor corneal central menor de 480 micras. Los pacientes fueron intervenidos con excímer láser (técnica de LASIK, en el Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología "Ramón Pando Ferrer", de diciembre de 2006 a marzo de 2007, con un seguimiento posoperatorio de 1 año, aunque se estimó el comportamiento de las variables al mes de la cirugía. RESULTADOS: Predominó discretamente el sexo femenino, el grupo de edad de 21 a 39 años constituyó el 81 %, y la miopía moderada en 74 ojos el 52,8 %. El valor de la presión intraocular con tonómetro de contorno dinámico superó al obtenido con el de Goldmann en 2 mm Hg en el preoperatorio y en 3,7 mm Hg en el posoperatorio. Se correlacionó la variación del espesor corneal posterior al LASIK y la presión intraocular según el tonómetro utlizado. CONCLUSIONES: Los valores de la presión con el tonómetro de Pascal son más confiables que los obtenidos con el tonómetro de aplanación de Goldmann, cuando el espesor corneal central se aleja de lo estipulado como normal.OBJECTIVES: To compare the intraocular pressure figures obtained with Goldman applanation tonometer and with Pascal dynamic contour tonometer, as well as the central corneal thickness variation before and after the refractive surgery with LASIK, and to set the relationship between both tonometers. METHODS: Seventy four patients (140 eyes aged over 21 years, with stable myopia (-1 to -10 dioptres, cylinder defect

30 CFR 56.12033 - Hand-held electric tools.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held electric tools. 56.12033 Section 56.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL....12033 Hand-held electric tools. Hand-held electric tools shall not be operated at high potential...

30 CFR 57.12033 - Hand-held electric tools.

Science.gov (United States)

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...

Intraocular pressure in a cohort of healthy eastern European schoolchildren: variations in method and corneal thickness

Directory of Open Access Journals (Sweden)

Krzyżanowska-Berkowska Patrycja

2012-12-01

Full Text Available Abstract Background Intraocular pressure (IOP in the developing eye of a child is not always easy to measure and there is no technique that is known to be the most accurate for the young eye. Measurements are needed on many cohorts of children with different tonometers to determine how the values correlate between instruments, whether corneal parameters affect readings and whether correlations between age and IOP values can be discerned. The aim of this study was to undertake a comparative analysis of three different tonometers on a group of healthy children to see whether differences exist and whether these may be related to central corneal thickness and/or radius of curvature. In addition, the study adds to the relatively small body of literature on IOP in the growing eye which will collectively allow trends to be identified and ultimately norms to be established. Methods IOP was measured on 115 eyes in a group of Polish children, aged between 5–17 years (mean ± standard deviation [SD] 11.3 ± 3.0 years using three different tonometers: non-contact (NCT, the ICare and Goldmann applanation (GAT. Readings obtained were compared between instruments and with central corneal thickness and radius of curvature. Results The ICare tonometer provided statistically higher IOP values (16.9 ± 3.4 mmHg than the GAT (14.7 ± 2.9 mmHg regardless of corneal thickness and whether or not a correction factor was applied. A correlation was found between central corneal thickness (CCT and IOP values obtained with all three tonometers but only the IOP values detected with the ICare tonometer showed a statistically significant correlation with radius of curvature (p  Conclusions IOP measurements on children vary significantly between instruments and correlations are affected by the corneal thickness. Further studies on children are needed to determine which instrument is most appropriate and to derive a normative IOP scale for the growing eye.

Correcting for motion artifact in handheld laser speckle images

Science.gov (United States)

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 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.

Measurement of intraocular pressure in healthy unanesthetized inland bearded dragons (Pogona vitticeps).

Science.gov (United States)

Schuster, Eva J; Strueve, Julia; Fehr, Michael J; Mathes, Karina A

2015-06-01

To evaluate the use of rebound and applanation tonometry for the measurement of intraocular pressure (IOP) and to assess diurnal variations in and the effect of topical anesthesia on the IOP of healthy inland bearded dragons (Pogona vitticeps). 56 bearded dragons from 4 months to 11 years old. For each animal following an initial ophthalmic examination, 3 IOP measurements were obtained on each eye between 9 AM and 10 AM, 1 PM and 2 PM, and 5 PM and 7 PM by use of rebound and applanation tonometry. An additional measurement was obtained by rebound tonometry for each eye in the evening following the application of a topical anesthetic to evaluate changes in the tolerance of the animals to the tonometer. Descriptive data were generated, and the effects of sex, time of day, and topical anesthesia on IOP were evaluated. Bearded dragons did not tolerate applanation tonometry even following topical anesthesia. Median daily IOP as determined by rebound tonometry was 6.16 mm Hg (95% confidence interval, 5.61 to 6.44 mm Hg). The IOP did not differ significantly between the right and left eyes. The IOP was highest in the morning, which indicated that the IOP in this species undergoes diurnal variations. Topical anesthesia did not significantly affect IOP, but it did improve the compliance for all subjects. Results indicated that rebound tonometry, but not applanation tonometry, was appropriate for measurement of IOP in bearded dragons. These findings provided preliminary guidelines for IOP measurement and ophthalmic evaluation in bearded dragons.

Measurements of intraocular pressure by Goldmann tonometry, Tonopen XL, and the transpalpebral tonometer, TGDc-01, after penetrating keratoplasty: a comparativye study.

Science.gov (United States)

Shemesh, Gabi; Waisbourd, Michael; Varssano, David; Michaeli, Adi; Lazar, Moshe; Kurtz, Shimon

2009-08-01

The aim of this study was to compare intraocular pressure (IOP) measurements obtained by Goldmann tonometry (GT), the Tonopen XL, and a new transpalpebral tonometer, TGDc-01, in eyes that had undergone penetrating keratoplasty (PKP). IOP was measured in post-PKP eyes by means of GT, Tonopen XL, and TGDc-01. Central corneal thickness measurements were also obtained for all eyes. Forty-five eyes of 43 patients were enrolled in the study. The mean IOP difference (+/-SD) was -0.42 +/- 5.83 mm Hg between GT and Tonopen and 3.20 +/- 7.55 mm Hg between GT and TGDc-01. The correlation coefficient was 0.84 between GT and Tonopen XL (P tonometer is simply inaccurate or whether avoiding contact with the corneal graft by measuring IOP through the eyelid enables it to provide more accurate IOP readings than those obtained by transcorneal techniques.

Image Quality Characteristics of Handheld Display Devices for Medical Imaging

Science.gov (United States)

Yamazaki, Asumi; Liu, Peter; Cheng, Wei-Chung; Badano, Aldo

2013-01-01

Handheld devices such as mobile phones and tablet computers have become widespread with thousands of available software applications. Recently, handhelds are being proposed as part of medical imaging solutions, especially in emergency medicine, where immediate consultation is required. However, handheld devices differ significantly from medical workstation displays in terms of display characteristics. Moreover, the characteristics vary significantly among device types. We investigate the image quality characteristics of various handheld devices with respect to luminance response, spatial resolution, spatial noise, and reflectance. We show that the luminance characteristics of the handheld displays are different from those of workstation displays complying with grayscale standard target response suggesting that luminance calibration might be needed. Our results also demonstrate that the spatial characteristics of handhelds can surpass those of medical workstation displays particularly for recent generation devices. While a 5 mega-pixel monochrome workstation display has horizontal and vertical modulation transfer factors of 0.52 and 0.47 at the Nyquist frequency, the handheld displays released after 2011 can have values higher than 0.63 at the respective Nyquist frequencies. The noise power spectra for workstation displays are higher than 1.2×10−5 mm2 at 1 mm−1, while handheld displays have values lower than 3.7×10−6 mm2. Reflectance measurements on some of the handheld displays are consistent with measurements for workstation displays with, in some cases, low specular and diffuse reflectance coefficients. The variability of the characterization results among devices due to the different technological features indicates that image quality varies greatly among handheld display devices. PMID:24236113

Wireless Handhelds to Support Clinical Nursing Practicum

Science.gov (United States)

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…

Digital forensics for handheld devices

CERN Document Server

Doherty, Eamon P

2012-01-01

Approximately 80 percent of the world's population now owns a cell phone, which can hold evidence or contain logs about communications concerning a crime. Cameras, PDAs, and GPS devices can also contain information related to corporate policy infractions and crimes. Aimed to prepare investigators in the public and private sectors, Digital Forensics for Handheld Devices examines both the theoretical and practical aspects of investigating handheld digital devices. This book touches on all areas of mobile device forensics, including topics from the legal, technical, academic, and social aspects o

ITSY Handheld Software Radio

National Research Council Canada - National Science Library

Bose, Vanu

2001-01-01

.... A handheld software radio platform would enable the construction of devices that could inter-operate with multiple legacy systems, download new waveforms and be used to construct adhoc networks...

Comparison of the biometric formulas used for applanation A-scan ultrasound biometry.

Science.gov (United States)

Özcura, Fatih; Aktaş, Serdar; Sağdık, Hacı Murat; Tetikoğlu, Mehmet

2016-10-01

The purpose of the study was to compare the accuracy of various biometric formulas for predicting postoperative refraction determined using applanation A-scan ultrasound. This retrospective comparative study included 485 eyes that underwent uneventful phacoemulsification with intraocular lens (IOL) implantation. Applanation A-scan ultrasound biometry and postoperative manifest refraction were obtained in all eyes. Biometric data were entered into each of the five IOL power calculation formulas: SRK-II, SRK/T, Holladay I, Hoffer Q, and Binkhorst II. All eyes were divided into three groups according to axial length: short (≤22.0 mm), average (22.0-25.0 mm), and long (≥25.0 mm) eyes. The postoperative spherical equivalent was calculated and compared with the predicted refractive error using each biometric formula. The results showed that all formulas had significantly lower mean absolute error (MAE) in comparison with Binkhorst II formula (P < 0.01). The lowest MAE was obtained with the SRK-II for average (0.49 ± 0.40 D) and short (0.67 ± 0.54 D) eyes and the SRK/T for long (0.61 ± 0.50 D) eyes. The highest postoperative hyperopic shift was seen with the SRK-II for average (46.8 %), short (28.1 %), and long (48.4 %) eyes. The highest postoperative myopic shift was seen with the Holladay I for average (66.4 %) and long (71.0 %) eyes and the SRK/T for short eyes (80.6 %). In conclusion, the SRK-II formula produced the lowest MAE in average and short eyes and the SRK/T formula produced the lowest MAE in long eyes. The SRK-II has the highest postoperative hyperopic shift in all eyes. The highest postoperative myopic shift is with the Holladay I for average and long eyes and SRK/T for short eyes.

Intraocular pressure in a cohort of healthy eastern European schoolchildren: variations in method and corneal thickness

Science.gov (United States)

2012-01-01

Background Intraocular pressure (IOP) in the developing eye of a child is not always easy to measure and there is no technique that is known to be the most accurate for the young eye. Measurements are needed on many cohorts of children with different tonometers to determine how the values correlate between instruments, whether corneal parameters affect readings and whether correlations between age and IOP values can be discerned. The aim of this study was to undertake a comparative analysis of three different tonometers on a group of healthy children to see whether differences exist and whether these may be related to central corneal thickness and/or radius of curvature. In addition, the study adds to the relatively small body of literature on IOP in the growing eye which will collectively allow trends to be identified and ultimately norms to be established. Methods IOP was measured on 115 eyes in a group of Polish children, aged between 5–17 years (mean ± standard deviation [SD] 11.3 ± 3.0 years) using three different tonometers: non-contact (NCT), the ICare and Goldmann applanation (GAT). Readings obtained were compared between instruments and with central corneal thickness and radius of curvature. Results The ICare tonometer provided statistically higher IOP values (16.9 ± 3.4 mmHg) than the GAT (14.7 ± 2.9 mmHg) regardless of corneal thickness and whether or not a correction factor was applied. A correlation was found between central corneal thickness (CCT) and IOP values obtained with all three tonometers but only the IOP values detected with the ICare tonometer showed a statistically significant correlation with radius of curvature (p < 0.004). No correlations with age or gender were found for IOP values measured with any of the instruments. Conclusions IOP measurements on children vary significantly between instruments and correlations are affected by the corneal thickness. Further studies on children are needed to determine which

Monitoring Microcirculatory Blood Flow with a New Sublingual Tonometer in a Porcine Model of Hemorrhagic Shock

Directory of Open Access Journals (Sweden)

Péter Palágyi

2015-01-01

Full Text Available Tissue capnometry may be suitable for the indirect evaluation of regional hypoperfusion. We tested the performance of a new sublingual capillary tonometer in experimental hemorrhage. Thirty-six anesthetized, ventilated mini pigs were divided into sham-operated (n=9 and shock groups (n=27. Hemorrhagic shock was induced by reducing mean arterial pressure (MAP to 40 mmHg for 60 min, after which fluid resuscitation started aiming to increase MAP to 75% of the baseline value (60–180 min. Sublingual carbon-dioxide partial pressure was measured by tonometry, using a specially coiled silicone rubber tube. Mucosal red blood cell velocity (RBCV and capillary perfusion rate (CPR were assessed by orthogonal polarization spectral (OPS imaging. In the 60 min shock phase a significant drop in cardiac index was accompanied by reduction in sublingual RBCV and CPR and significant increase in the sublingual mucosal-to-arterial PCO2 gap (PSLCO2 gap, which significantly improved during the 120 min resuscitation phase. There was significant correlation between PSLCO2 gap and sublingual RBCV (r=-0.65, p<0.0001, CPR (r=-0.64, p<0.0001, central venous oxygen saturation (r=-0.50, p<0.0001, and central venous-to-arterial PCO2 difference (r=0.62, p<0.0001. This new sublingual tonometer may be an appropriate tool for the indirect evaluation of circulatory changes in shock.

Introduction of handheld computing to a family practice residency program.

Science.gov (United States)

Rao, Goutham

2002-01-01

Handheld computers are valuable practice tools. It is important for residency programs to introduce their trainees and faculty to this technology. This article describes a formal strategy to introduce handheld computing to a family practice residency program. Objectives were selected for the handheld computer training program that reflected skills physicians would find useful in practice. TRGpro handheld computers preloaded with a suite of medical reference programs, a medical calculator, and a database program were supplied to participants. Training consisted of four 1-hour modules each with a written evaluation quiz. Participants completed a self-assessment questionnaire after the program to determine their ability to meet each objective. Sixty of the 62 participants successfully completed the training program. The mean composite score on quizzes was 36 of 40 (90%), with no significant differences by level of residency training. The mean self-ratings of participants across all objectives was 3.31 of 4.00. Third-year residents had higher mean self-ratings than others (mean of group, 3.62). Participants were very comfortable with practical skills, such as using drug reference software, and less comfortable with theory, such as knowing the different types of handheld computers available. Structured training is a successful strategy for introducing handheld computing to a residency program.

Intraocular pressure following 18 hours of systemic dehydration in ocular normotensive healthy subjects

Directory of Open Access Journals (Sweden)

Faustina K. Idu

2015-07-01

Full Text Available Aim: To investigate the effect of dehydration on intraocular pressure (IOP. Subjects: The study population comprised 50 subjects (27 men and 23 women with a mean age of 42.84 ± 2.64 years. Method: The subjects dehydrated for 18 hours. IOP was assessed in both eyes using the Perkins handheld applanation tonometer. Baseline measurement of IOP was taken before the subjects dehydrated for 18 hours and repeated after dehydration. Blood samples were taken before and after dehydration for the determination of plasma osmolality and plasma antidiuretic hormone (ADH concentrations. Results: A statistically significant (p < 0.001 reduction in the mean weight of subjects occurred after dehydration. There was a significant reduction in IOP from 16.68 mmHg ± 0.32 mmHg to 13.08 mmHg ± 0.31 mmHg after dehydration (p < 0.001. Mean plasma osmolality showed a statistically significant increase (p < 0.05 from baseline of 290.02 mOsmol/kg ± 1.25 mOsmol/kg to 294.96 mOsmol/kg ± 1.33 mOsmol/kg after dehydration. There was also a significant increase (p < 0.05 in mean plasma ADH concentration from 5.36 pg/mL ± 0.21 pg/mL to 6.40 pg/mL ± 0.20 pg/mL after dehydration. There were no significant differences in both systolic and diastolic blood pressures before and after dehydration. Conclusion: Dehydration decreases IOP in healthy humans; this decrease probably results from an increase in plasma osmolality and plasma ADH concentrations.

Navigating on handheld displays: Dynamic versus Static Keyhole Navigation

NARCIS (Netherlands)

Mehra, S.; Werkhoven, P.; Worring, M.

2006-01-01

Handheld displays leave little space for the visualization and navigation of spatial layouts representing rich information spaces. The most common navigation method for handheld displays is static peephole navigation: The peephole is static and we move the spatial layout behind it (scrolling). A

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

Science.gov (United States)

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.

Characteristics of corneal biomechanical responses detected by a non-contact scheimpflug-based tonometer in eyes with glaucoma.

Science.gov (United States)

Jung, Younhea; Park, Hae-Young L; Yang, Hee Jung; Park, Chan Kee

2017-11-01

To determine the corneal biomechanical properties in eyes with glaucoma using a non-contact Scheimpflug-based tonometer. Corneal biomechanical responses were examined using a non-contact Scheimpflug-based tonometer. The tonometer parameters of the normal control group (n = 75) were compared with those of the glaucoma group (n = 136), including an analysis of glaucoma subgroups categorized by visual field loss. After adjusting for potential confounding factors, including the intraocular pressure (IOP), central corneal thickness (CCT), age and axial length, the deformation amplitude was smaller in the glaucoma group (1.09 ± 0.02 mm) than in the normal control group (1.12 ± 0.02 mm; p value = 0.031). The deformation amplitude and the deflection amplitude of the severe glaucoma group (1.12 ± 0.02 mm and 0.92 ± 0.01 mm) were significantly greater than that of the early glaucoma group (1.07 ± 0.01   mm and 0.88 ± 0.11 mm, p = 0.006 and p = 0.031), whereas that of the moderate glaucoma group (1.09 ± 0.02 mm and 0.90 ± 0.02 mm) was greater than that of the early glaucoma group, but this difference was not statistically significant. The deformation amplitude showed a negative correlation with the CCT in the normal control group (r = -0.235), with a weaker negative relationship observed in the early glaucoma group (r = -0.099). However, in the moderate and severe glaucoma groups, the deformation amplitude showed a positive relationship with the CCT, showing an inverse relationship. The duration and number of antiglaucomatous eyedrops used had negative correlations with the CCT in eyes with moderate and severe glaucoma. Overall, the glaucoma group showed significantly less deformable corneas than did the normal controls, even after adjusting for the IOP, CCT, age and axial length. However, there were also differences according to the severity of glaucoma, where the corneal deformation amplitude was greater in the severe glaucoma

Handheld spectrometers: the state of the art

Science.gov (United States)

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.

Evaluation of rebound tonometry in non-human primates.

Science.gov (United States)

Elsmo, Elizabeth J; Kiland, Julie A; Kaufman, Paul L; McLellan, Gillian J

2011-04-01

To determine the accuracy and reproducibility of intraocular pressure (IOP) measurements obtained with the TonoVet® rebound tonometer in cynomolgus macaques and to determine the effects of corneal thickness on measurements obtained by the TonoVet®. The anterior chambers of both eyes of anesthetized monkeys were cannulated with branched 23-G needles; one branch was connected to a vertically adjustable reservoir and the other to a pressure transducer. IOP was increased by 5 mmHg increments and then decreased by 10 mmHg decrements. IOP was measured using the TonoVet® at each increment and decrement by 2 independent observers and at every other increment and every decrement by a single observer using 'minified' Goldmann applanation tonometry. Central corneal thickness was measured with a PachPen(TM) ultrasonic pachymeter. TonoVet® readings correlated well with manometric IOP (slope = 0.972, r(2) coefficient = 0.955). No significant differences were observed when comparing eyes or operators; however there was a non-significant trend for TonoVet® readings taken in right eyes to be closer to manometric IOP than those taken in left eyes. The TonoVet® had a non-significant tendency to underestimate manometric IOP. TonoVet® readings obtained during the decremental phase of the experiment were significantly closer (p tonometer is a reliable and accurate tool for the measurement of IOP in cynomolgus macaques. This tonometer has several advantages, including portability, ease of use, and brief contact with the corneal surface making topical anesthetics unnecessary. Copyright © 2011 Elsevier Ltd. All rights reserved.

Data for Users of Handheld Ion Mobility Spectrometers

International Nuclear Information System (INIS)

Keith A. Daum; Sandra L. Fox

2008-01-01

Chemical detection technology end-user surveys conducted by Idaho National Laboratory (INL) in 2005 and 2007 indicated that first responders believed manufacturers claims for instruments sometimes were not supported in field applications, and instruments sometimes did not meet their actual needs. Based on these findings, the Department of Homeland Security (DHS) asked INL to conduct a similar survey for handheld ion mobility spectrometers (IMS), which are used by a broad community of first responders as well as for other applications. To better access this broad community, the INL used the Center for Technology Commercialization, Inc. (CTC), Public Safety Technology Center (PSTC) to set up an online framework to gather information from users of handheld IMS units. This framework (Survey Monkey) was then used to perform an online Internet survey, augmented by e-mail prompts, to get information from first responders and personnel from various agencies about their direct experience with handheld IMS units. Overall, 478 individuals responded to the survey. Of these, 174 respondents actually owned a handheld IMS. Performance and satisfaction data from these 174 respondents are captured in this report. The survey identified the following observations: (1) The most common IMS unit used by respondents was the Advanced Portable Detector (APD 2000), followed by ChemRae, Sabre 4000, Sabre 2000, Draeger Multi IMS, Chemical Agent Monitor-2, Chemical Agent Monitor, Vapor Tracer, and Vapor Tracer 2. (2) The primary owners were HazMat teams (20%), fire services (14%), local police (12%), and sheriffs departments (9%). (3) IMS units are seldom used as part of an integrated system for detecting and identifying chemicals but instead are used independently. (4) Respondents are generally confused about the capabilities of their IMS unit. This is probably a result of lack of training. (5) Respondents who had no training or fewer than 8 hours were not satisfied with the overall operation

Electronic prescribing: criteria for evaluating handheld prescribing systems and an evaluation of a new, handheld, wireless wide area network (WWAN) prescribing system.

Science.gov (United States)

Goldblum, O M

2001-02-01

The objectives of this study were: 1) to establish criteria for evaluating handheld computerized prescribing systems; and 2) to evaluate out-of-box performance and features of a new, Palm Operating System (OS)-based, handheld, wireless wide area network (WWAN) prescribing system. The system consisted of a Palm Vx handheld organizer, a Novatel Minstrel V wireless modem, OmniSky wireless internet access and ePhysician ePad 1.1, the Palm OS electronic prescribing software program. A dermatologist familiar with healthcare information technology conducted an evaluation of the performance and features of a new, handheld, WWAN electronic prescribing system in an office practice during a three-month period in 2000. System performance, defined as transmission success rate, was determined from data collected during the three-month trial. Evaluation criteria consisted of an analysis of features found in electronic prescribing systems. All prescriptions written for all patients seen during a three-month period (August - November, 2000) were eligible for inclusion. Prescriptions written for patients who intended to fill them at pharmacies without known facsimile receiving capabilities were excluded from the study. The performance of the system was evaluated using data collected during the study. Criteria for evaluating features of electronic prescribing systems were developed and used to analyze the system employed in this study. During this three-month trial, 200 electronic prescriptions were generated for 132 patients included in the study. Of these prescriptions, 92.5 percent were successfully transmitted to pharmacies. Transmission failures resulted from incorrect facsimile numbers and non-functioning facsimile machines. Criteria established for evaluation of electronic prescribing systems included System (Hardware & Software), Costs, System Features, Printing & Transmission, Formulary & Insurance, Customization, Drug Safety and Security. This study is the first effort to

The Pulsair 3000 tonometer--how many readings need to be taken to ensure accuracy of the average?

Science.gov (United States)

McCaghrey, G E; Matthews, F E

2001-07-01

Manufacturers of non-contact tonometers recommend that a number of readings are taken on each eye, and an average obtained. With the Keeler Pulsair 3000 it is advised to take four readings, and average these. This report analyses readings in 100 subjects, and compares the first reading, and the averages of the first two and first three readings with the "machine standard" of the average of four readings. It is found that, in the subject group investigated, the average of three readings is not different from the average of four in 95% of individuals, with equivalence defined as +/- 1.0 mmHg.

The influence of lens power and center thickness on the intraocular pressure measured through soft lenses: a comparison of two noncontact tonometers.

Science.gov (United States)

Ogbuehi, Kelechi C

2012-06-01

To quantify the influence of soft contact lens power and thickness on the intraocular pressure (IOP). Thirty-nine young, healthy adult volunteers completed this study. One eye of each subject was randomly assigned either a +6D or a -6D high water content daily disposable lens. The other eye was fitted with the second lens. Triplicate measurements of IOP were taken before, during, and after contact lens wear. Each time, IOP was assessed in a randomized order with two noncontact tonometers. The lenses were swapped between eyes during a second session of measurements, one week later. In the first session with the +6D lenses, the average IOPs (±SDs) before, with the lenses fitted, and after the lenses were removed, were: 14.3 ± 2.9 mmHg, 17.0 ± 3.3 mmHg and 13.9 ± 3.1 mmHg, respectively, for the CT80 and 13.6 ± 3.1 mmHg, 17.1 ± 4.5 mmHg and 13.3 ± 2.9 mmHg, respectively, for the PT100. The corresponding values for the first session with the -6D lenses were: 14.3 ± 3.1 mmHg, 13.1 ± 3.1 mmHg and 14.1 ± 3.3 mmHg, respectively, for the CT80 and 13.6 ± 3.2 mmHg, 13.0 ± 3.0 mmHg and 13.6 ± 3.2 mmHg, respectively, for the PT100. IOP significantly (Psoft contact lens-induced changes were consistent between sessions but varied between tonometers. The measurement of IOP through soft contact lenses resulted in consistent, statistically significant differences in IOP, which were not uniform across tonometers and which did not appear to be solely related to the central thickness of the soft contact lenses. Copyright © 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Handheld Microfluidic Blood Ananlyzer, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Nanohmics proposes to develop a handheld blood analyzer for micro- and hypo-gravity missions. The prototype instrument will combine impedance analysis with optical...

Handheld CAT Video Game, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed project is to design, develop and fabricate a handheld video game console for astronauts during long space flight. This portable hardware runs...

A Cognitive Style Perspective to Handheld Devices: Customization vs. Personalization

Science.gov (United States)

Hsieh, Chen-Wei; Chen, Sherry Y.

2016-01-01

Handheld devices are widely applied to support open and distributed learning, where students are diverse. On the other hand, customization and personalization can be applied to accommodate students' diversities. However, paucity of research compares the effects of customization and personalization in the context of handheld devices. To this end, a…

Characterizing the reflectivity of handheld display devices.

Science.gov (United States)

Liu, Peter; Badano, Aldo

2014-08-01

With increased use of handheld and tablet display devices for viewing medical images, methods for consistently measuring reflectivity of the devices are needed. In this note, the authors report on the characterization of diffuse reflections for handheld display devices including mobile phones and tablets using methods recommended by the American Association of Physicists in Medicine Task Group 18 (TG18). The authors modified the diffuse reflectance coefficient measurement method outlined in the TG18 report. The authors measured seven handheld display devices (two phones and five tablets) and three workstation displays. The device was attached to a black panel with Velcro. To study the effect of the back surface on the diffuse reflectance coefficient, the authors created Styrofoam masks with different size square openings and placed it in front of the device. Overall, for each display device, measurements of illuminance and reflected luminance on the display screen were taken. The authors measured with no mask, with masks of varying size, and with display-size masks, and calculated the corresponding diffuse reflectance coefficient. For all handhelds, the diffuse reflectance coefficient measured with no back panel were lower than measurements performed with a mask. The authors found an overall increase in reflectivity as the size of the mask decreases. For workstations displays, diffuse reflectance coefficients were higher when no back panel was used, and higher than with masks. In all cases, as luminance increased, illuminance increased, but not at the same rate. Since the size of handheld displays is smaller than that of workstation devices, the TG18 method suffers from a dependency on illumination condition. The authors show that the diffuse reflection coefficients can vary depending on the nature of the back surface of the illuminating box. The variability in the diffuse coefficient can be as large as 20% depending on the size of the mask. For all measurements

Driver hand-held cellular phone use: a four-year analysis.

Science.gov (United States)

Eby, David W; Vivoda, Jonathon M; St Louis, Renée M

2006-01-01

The use of hand-held cellular (mobile) phones while driving has stirred more debate, passion, and research than perhaps any other traffic safety issue in the past several years. There is ample research showing that the use of either hand-held or hands-free cellular phones can lead to unsafe driving patterns. Whether or not these performance deficits increase the risk of crash is difficult to establish, but recent studies are beginning to suggest that cellular phone use elevates crash risk. The purpose of this study was to assess changes in the rate of hand-held cellular phone use by motor-vehicle drivers on a statewide level in Michigan. This study presents the results of 13 statewide surveys of cellular phone use over a 4-year period. Hand-held cellular phone use data were collected through direct observation while vehicles were stopped at intersections and freeway exit ramps. Data were weighted to be representative of all drivers traveling during daylight hours in Michigan. The study found that driver hand-held cellular phone use has more than doubled between 2001 and 2005, from 2.7% to 5.8%. This change represents an average increase of 0.78 percentage points per year. The 5.8% use rate observed in 2005 means that at any given daylight hour, around 36,550 drivers were conversing on cellular phones while driving on Michigan roadways. The trend line fitted to these data predicts that by the year 2010, driver hand-held cellular phone use will be around 8.6%, or 55,000 drivers at any given daylight hour. These results make it clear that cellular phone use while driving will continue to be an important traffic safety issue, and highlight the importance of continued attempts to generate new ways of alleviating this potential hazard.

Effect of Hemifacial Spasm on Intraocular Pressure Measurement.

Science.gov (United States)

Cicik, Erdogan; Yildirim, Rengin; Arici, Ceyhun; Dikkaya, Funda; Arslan, Osman Sevki

2018-01-01

To evaluate the effect of hemifacial spasm (HFS) on intraocular pressure (IOP) measurement. Twenty-four consecutive patients with HFS and 25 age- and gender-matched randomly selected eyes of healthy volunteers underwent corneal pachymetry and IOP measurements using Goldmann applanation tonometer (GAT) and noncontact tonometer (NCT). IOP measurements were performed before (during HFS) and 2 weeks after Botox injections in HFS patients and in healthy volunteers without Botox injections. There was no statistical difference between involved eye side and uninvolved eye side of HFS patients in measured central corneal thickness. Similarly, no difference was found between involved eye side of HFS patients and controls. There were no statistically significant differences comparing IOP values before treatment and levels measured at 2 weeks of Botox injections, either with GAT ( p = 0.33, 0.11) or NCT ( p = 0.80, 0.43) devices in the involved eyes and uninvolved eyes of patients with HFS, respectively. There were also no significant differences in these parameters (GAT ( p = 0.63) and NCT ( p = 0.54)) in controls. Contractions in facial muscles may not lead to significant increase in IOP in HFS patients. This result may help clinical decision making in the treatment of glaucoma patients with HFS. This trial is registered with NCT03390803.

75 FR 27504 - Substantial Product Hazard List: Hand-Held Hair Dryers

Science.gov (United States)

2010-05-17

... immersion during their use. Section 15(a) of the CPSA defines ``substantial product hazard'' to include, a....'' Hand-held hair dryers routinely contain open-coil heating elements that are, in essence, uninsulated..., bathtub, or lavatory). The proposed rule would define ``hand-held hair dryer'' as ``an electrical...

Prospective evaluation of an internet-linked handheld computer critical care knowledge access system.

Science.gov (United States)

Lapinsky, Stephen E; Wax, Randy; Showalter, Randy; Martinez-Motta, J Carlos; Hallett, David; Mehta, Sangeeta; Burry, Lisa; Stewart, Thomas E

2004-12-01

Critical care physicians may benefit from immediate access to medical reference material. We evaluated the feasibility and potential benefits of a handheld computer based knowledge access system linking a central academic intensive care unit (ICU) to multiple community-based ICUs. Four community hospital ICUs with 17 physicians participated in this prospective interventional study. Following training in the use of an internet-linked, updateable handheld computer knowledge access system, the physicians used the handheld devices in their clinical environment for a 12-month intervention period. Feasibility of the system was evaluated by tracking use of the handheld computer and by conducting surveys and focus group discussions. Before and after the intervention period, participants underwent simulated patient care scenarios designed to evaluate the information sources they accessed, as well as the speed and quality of their decision making. Participants generated admission orders during each scenario, which were scored by blinded evaluators. Ten physicians (59%) used the system regularly, predominantly for nonmedical applications (median 32.8/month, interquartile range [IQR] 28.3-126.8), with medical software accessed less often (median 9/month, IQR 3.7-13.7). Eight out of 13 physicians (62%) who completed the final scenarios chose to use the handheld computer for information access. The median time to access information on the handheld handheld computer was 19 s (IQR 15-40 s). This group exhibited a significant improvement in admission order score as compared with those who used other resources (P = 0.018). Benefits and barriers to use of this technology were identified. An updateable handheld computer system is feasible as a means of point-of-care access to medical reference material and may improve clinical decision making. However, during the study, acceptance of the system was variable. Improved training and new technology may overcome some of the barriers we

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

Science.gov (United States)

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…

Decisions at hand: a decision support system on handhelds.

Science.gov (United States)

Zupan, B; Porenta, A; Vidmar, G; Aoki, N; Bratko, I; Beck, J R

2001-01-01

One of the applications of clinical information systems is decision support. Although the advantages of utilizing such aids have never been theoretically disputed, they have been rarely used in practice. The factor that probably often limits the utility of clinical decision support systems is the need for computing power at the very site of decision making--at the place where the patient is interviewed, in discussion rooms, etc. The paper reports on a possible solution to this problem. A decision-support shell LogReg is presented, which runs on a handheld computer. A general schema for handheld-based decision support is also proposed, where decision models are developed on personal computers/workstations, encoded in XML and then transferred to handhelds, where the models are used within a decision support shell. A use case where LogReg has been applied to clinical outcome prediction in crush injury is presented.

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

Science.gov (United States)

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.

Augmented Reality Simulations on Handheld Computers

Science.gov (United States)

Squire, Kurt; Klopfer, Eric

2007-01-01

Advancements in handheld computing, particularly its portability, social interactivity, context sensitivity, connectivity, and individuality, open new opportunities for immersive learning environments. This article articulates the pedagogical potential of augmented reality simulations in environmental engineering education by immersing students in…

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

Science.gov (United States)

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.

Development of Real-Time Dual-Display Handheld and Bench-Top Hybrid-Mode SD-OCTs

Directory of Open Access Journals (Sweden)

Nam Hyun Cho

2014-01-01

Full Text Available Development of a dual-display handheld optical coherence tomography (OCT system for retina and optic-nerve-head diagnosis beyond the volunteer motion constraints is reported. The developed system is portable and easily movable, containing the compact portable OCT system that includes the handheld probe and computer. Eye posterior chambers were diagnosed using the handheld probe, and the probe could be fixed to the bench-top cradle depending on the volunteers’ physical condition. The images obtained using this handheld probe were displayed in real time on the computer monitor and on a small secondary built-in monitor; the displayed images were saved using the handheld probe’s built-in button. Large-scale signal-processing procedures such as k-domain linearization, fast Fourier transform (FFT, and log-scaling signal processing can be rapidly applied using graphics-processing-unit (GPU accelerated processing rather than central-processing-unit (CPU processing. The Labview-based system resolution is 1,024 × 512 pixels, and the frame rate is 56 frames/s, useful for real-time display. The 3D images of the posterior chambers including the retina, optic-nerve head, blood vessels, and optic nerve were composed using real-time displayed images with 500 × 500 × 500 pixel resolution. A handheld and bench-top hybrid mode with a dual-display handheld OCT was developed to overcome the drawbacks of the conventional method.

Improving car passengers' comfort and experience by supporting the use of handheld devices.

Science.gov (United States)

van Veen, S A T; Hiemstra-van Mastrigt, S; Kamp, I; Vink, P

2014-01-01

There is a demand for interiors to support other activities in a car than controlling the vehicle. Currently, this is the case for the car passengers and--in the future--autonomous driving cars will also facilitate drivers to perform other activities. One of these activities is working with handheld devices. Previous research shows that people experience problems when using handheld devices in a moving vehicle and the use of handheld devices generally causes unwanted neck flexion [Young et al. 2012; Sin and Zu 2011; Gold et al.2011]. In this study, armrests are designed to support the arms when using handheld devices in a driving car in order to decrease neck flexion. Neck flexion was measured by attaching markers on the C7 and tragus. Discomfort was indicated on a body map on a scale 1-10. User experience was evaluated in a semi-structured interview. Neck flexion is significantly decreased by the support of the armrests and approaches a neutral position. Furthermore, overall comfort and comfort in the neck region specifically are significantly increased. Subjects appreciate the body posture facilitated by the armrests and 9 out of 10 prefer using handheld devices with the armrests compared to using handheld devices without the armrests. More efforts are needed to develop the mock-up into an established product, but the angles and dimensions presented in this study could serve as guidelines.

Ultrasonography with a hand-held device for the diagnosis of acute appendicitis

International Nuclear Information System (INIS)

Kameda, Toru; Takahashi, Isao

2009-01-01

The purpose of this study was to evaluate the accuracy of ultrasonography (US) with a hand-held device for the diagnosis of acute appendicitis in the emergency room. US with a hand-held device was performed by the first author in 33 patients suspected of having appendicitis in the emergency room. From these 33 patients, 24 who subsequently underwent computed tomography (CT) or surgery were included in this study. The accuracy of US with the hand-held device for the diagnosis of acute appendicitis was evaluated based on the findings of CT or surgery. CT and surgery were performed in 22 and 12 patients, respectively. Final diagnoses were acute appendicitis (n=18), terminal ileitis (n=2), pelvic inflammatory disease (n=2), diverticulitis (n=1), and ureterolithiasis (n=1). The US yielded a sensitivity of 78% and a positive predictive value of 100%. The shortest distance between the abdominal wall and the appendix measured on CT was less than 40 mm in 11 patients. In ten (91%) of the 11 patients US with the hand-held device showed the swollen appendix. US with a hand-held device is potentially useful in the positive identification of acute appendicitis, but further investigation is needed to prove its utility in the routine diagnosis of acute appendicitis. (author)

Introducing handheld computing into a residency program: preliminary results from qualitative and quantitative inquiry.

OpenAIRE

Manning, B.; Gadd, C. S.

2001-01-01

Although published reports describe specific handheld computer applications in medical training, we know very little yet about how, and how well, handheld computing fits into the spectrum of information resources available for patient care and physician training. This paper reports preliminary quantitative and qualitative results from an evaluation study designed to track changes in computer usage patterns and computer-related attitudes before and after introduction of handheld computing. Pre...

40 CFR 90.129 - Fuel tank permeation from handheld engines and equipment.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Fuel tank permeation from handheld... KILOWATTS Emission Standards and Certification Provisions § 90.129 Fuel tank permeation from handheld... equipment with respect to fuel tanks. For the purposes of this section, fuel tanks do not include fuel caps...

Fusing Open Source Intelligence and Handheld Situational Awareness - Benghazi Case Study

Science.gov (United States)

2014-10-01

1 DM-0001694 Fusing Open Source Intelligence and Handheld Situational Awareness Benghazi Case Study Jeff Boleng, PhD Marc Novakouski Gene...command and control element at the CIA compound that would have been monitoring OSINT and other sources of intelligence before the attack and... Source Intelligence and Handheld Situational Awareness - Benghazi Case Study 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

Handheld computers in nursing education: PDA pilot project.

Science.gov (United States)

Koeniger-Donohue, Rebecca

2008-02-01

Interest in the use and application of handheld technology at undergraduate and graduate nursing programs across the country is growing rapidly. Personal digital assistants (PDAs) are often referred to as a "peripheral brain" because they can save time, decrease errors, and simplify information retrieval at the point of care. In addition, research results support the notion that PDAs enhance nursing clinical education and are an effective student learning resource. However, most nursing programs lack the full range of technological resources to implement and provide ongoing support for handheld technology use by faculty and students. This article describes a 9-month pilot project for the initial use of PDAs by novice faculty and students at Simmons College.

Handheld ESPI-speckle interferometer

DEFF Research Database (Denmark)

Skov Hansen, René

2003-01-01

. The interferometer presented here is a compact version of the set-up, Which is capable of measuring displacements of small objects, having either a specularly reflecting-or a diffusely scattering surface. The small optical set-up together with the use of the popular USB-communication for acquiring the images...... and controlling the phase of the reference wave constitutes a compact "handheld" instrument and eliminates the need for installing extra hardware, such as frame grabber and Digital to Analog converter, in the host computer....

Handheld Multi-Gas Meters Market Survey Report

Energy Technology Data Exchange (ETDEWEB)

Williams, Gustavious [Brigham Young Univ., Provo, UT (United States); Wald-Hopkins, Mark David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Obrey, Stephen J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Akhadov, Valida Dushdurova [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-06-23

Handheld multi-gas meters (MGMs) are equipped with sensors to monitor oxygen (O2) levels and additional sensors to detect the presence of combustible or toxic gases in the environment. This report is limited to operational response-type MGMs that include at least four different sensors. These sensors can vary by type and by the chemical monitored. In real time, the sensors report the concentration of monitored gases in the atmosphere near the MGM. To provide emergency responders with information on handheld multi-gas meters, the System Assessment and Validation for Emergency Responders (SAVER) Program conducted a market survey. This market survey report is based on information gathered between November 2015 and February 2016 from vendors, Internet research, industry publications, an emergency responder focus group, and a government issued Request for Information (RFI) that was posted on the Federal Business Opportunities website.

Who’s That Girl? Handheld Augmented Reality for Printed Photo Books

OpenAIRE

Henze , Niels; Boll , Susanne

2011-01-01

Part 1: Long and Short Papers; International audience; Augmented reality on mobile phones has recently made major progress. Lightweight, markerless object recognition and tracking makes handheld Augmented Reality feasible for new application domains. As this field is technology driven the interface design has mostly been neglected. In this paper we investigate visualization techniques for augmenting printed documents using handheld Augmented Reality. We selected the augmentation of printed ph...

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

Science.gov (United States)

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 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.

Active case finding strategy for chronic obstructive pulmonary disease with handheld spirometry.

Science.gov (United States)

Kim, Joo Kyung; Lee, Chang Min; Park, Ji Young; Kim, Joo Hee; Park, Sung-Hoon; Jang, Seung Hun; Jung, Ki-Suck; Yoo, Kwang Ha; Park, Yong Bum; Rhee, Chin Kook; Kim, Deog Kyeom; Hwang, Yong Il

2016-12-01

The early detection and diagnosis of chronic obstructive pulmonary disease (COPD) is critical to providing appropriate and timely treatment. We explored a new active case-finding strategy for COPD using handheld spirometry.We recruited subjects over 40 years of age with a smoking history of more than 10 pack-years who visited a primary clinic complaining of respiratory symptoms. A total of 190 of subjects were enrolled. Medical information was obtained from historical records and physical examination by general practitioners. All subjects had their pulmonary function evaluated using handheld spirometry with a COPD-6 device. Because forced expiratory volume in 6 seconds (FEV6) has been suggested as an alternative to FVC, we measured forced expiratory volume in 1 second (FEV1)/FEV6 for diagnosis of airflow limitation. All subjects were then referred to tertiary referral hospitals to complete a "Could it be COPD?" questionnaire, handheld spiromtery, and conventional spirometry. The results of each instrument were compared to evaluate the efficacy of both handheld spirometry and the questionnaire.COPD was newly diagnosed in 45 (23.7%) patients. According to our receiver-operating characteristic (ROC) curve analysis, sensitivity and specificity were maximal when the FEV1/FEV6 ratio was less than 77%. The area under the ROC curve was 0.759. The sensitivity, specificity, positive predictive value, and negative predictive value were 72.7%, 77.1%, 50%, and 90%, respectively. The area under the ROC curve of respiratory symptoms listed on the questionnaire ranged from 0.5 to 0.65, which indicates that there is almost no difference compared with the results of handheld spirometry.The present study demonstrated the efficacy of handheld spirometry as an active case-finding tool for COPD in a primary clinical setting. This study suggested that physicians should recommend handheld spirometry for people over the age of 40, who have a smoking history of more than 10 pack

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

Science.gov (United States)

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

Position statement on use of hand-held portable dental X-ray equipment

International Nuclear Information System (INIS)

2014-06-01

The position statement focuses on justification in the medical field, in particular on the use of hand-held portable dental x-ray equipment. It supplements another HERCA position paper, providing a general overview of the use of all hand-held portable X-ray equipment. Key Messages: - HERCA finds that the use of hand-held portable X-ray devices should be discouraged except in special circumstances. - As a general rule, these devices should only be used in scenarios where an intraoral radiograph is deemed necessary for a patient and the use of a fixed or semi-mobile x-ray unit is impractical, e.g.: - nursing homes, residential care facilities or homes for persons with disabilities; - forensic odontology, - military operations abroad without dental facilities

Carbonaceous species emitted from handheld two-stroke engines

Science.gov (United States)

Volckens, John; Olson, David A.; Hays, Michael D.

Small, handheld two-stroke engines used for lawn and garden work (e.g., string trimmers, leaf blowers, etc.) can emit a variety of potentially toxic carbonaceous air pollutants. Yet, the emissions effluents from these machines go largely uncharacterized, constraining the proper development of human exposure estimates, emissions inventories, and climate and air quality models. This study samples and evaluates chemical pollutant emissions from the dynamometer testing of six small, handheld spark-ignition engines—model years 1998-2002. Four oil-gas blends were tested in each engine in duplicate. Emissions of carbon dioxide, carbon monoxide, and gas-phase hydrocarbons were predominant, and the PM emitted was organic matter primarily. An ANOVA model determined that engine type and control tier contributed significantly to emissions variations across all identified compound classes; whereas fuel blend was an insignificant variable accounting for engines were generally intermediate in magnitude compared with other gasoline-powered engines, numerous compounds traditionally viewed as motor vehicle markers are also present in small engine emissions in similar relative proportions. Given that small, handheld two-stroke engines used for lawn and garden work account for 5-10% of total US emissions of CO, CO 2, NO x, HC, and PM 2.5, source apportionment models and human exposure studies need to consider the effect of these small engines on ambient concentrations in air polluted environments.

A smartphone controlled handheld microfluidic liquid handling system.

Science.gov (United States)

Li, Baichen; Li, Lin; Guan, Allan; Dong, Quan; Ruan, Kangcheng; Hu, Ronggui; Li, Zhenyu

2014-10-21

Microfluidics and lab-on-a-chip technologies have made it possible to manipulate small volume liquids with unprecedented resolution, automation and integration. However, most current microfluidic systems still rely on bulky off-chip infrastructures such as compressed pressure sources, syringe pumps and computers to achieve complex liquid manipulation functions. Here, we present a handheld automated microfluidic liquid handling system controlled by a smartphone, which is enabled by combining elastomeric on-chip valves and a compact pneumatic system. As a demonstration, we show that the system can automatically perform all the liquid handling steps of a bead-based HIV1 p24 sandwich immunoassay on a multi-layer PDMS chip without any human intervention. The footprint of the system is 6 × 10.5 × 16.5 cm, and the total weight is 829 g including battery. Powered by a 12.8 V 1500 mAh Li battery, the system consumed 2.2 W on average during the immunoassay and lasted for 8.7 h. This handheld microfluidic liquid handling platform is generally applicable to many biochemical and cell-based assays requiring complex liquid manipulation and sample preparation steps such as FISH, PCR, flow cytometry and nucleic acid sequencing. In particular, the integration of this technology with read-out biosensors may help enable the realization of the long-sought Tricorder-like handheld in vitro diagnostic (IVD) systems.

New portable hand-held radiation instruments for measurements and monitoring

International Nuclear Information System (INIS)

Fehlau, P.E.

1987-01-01

Hand-held radiation monitors are often used to search pedestrians and motor vehicles for special nuclear material (SNM) as part of a physical protection plan for nuclear materials. Recently, the Los Alamos Advanced Nuclear Technology group has commercialized an improved hand-held monitor that can be used for both physical-protection monitoring and verification measurements in nuclear material control and waste management. The new monitoring instruments are smaller and lighter; operate much longer on a battery charge; are available with NaI(Tl) or neutron and gamma-ray sensitive plastic scintillation detectors; and are less expensive than other comparable instruments. They also have a second operating mode for making precise measurements over counting times as long as 99 s. This mode permits making basic verification measurements that may be needed before transporting nuclear material or waste outside protected areas. Improved verification measurements can be made with a second new hand-held instrument that has a stabilized detector and three separate gamma-ray energy windows to obtain spectral information for SNM quantity, enrichment, or material-type verification

Handheld low-temperature plasma probe for portable "point-and-shoot" ambient ionization mass spectrometry.

Science.gov (United States)

Wiley, Joshua S; Shelley, Jacob T; Cooks, R Graham

2013-07-16

We describe a handheld, wireless low-temperature plasma (LTP) ambient ionization source and its performance on a benchtop and a miniature mass spectrometer. The source, which is inexpensive to build and operate, is battery-powered and utilizes miniature helium cylinders or air as the discharge gas. Comparison of a conventional, large-scale LTP source against the handheld LTP source, which uses less helium and power than the large-scale version, revealed that the handheld source had similar or slightly better analytical performance. Another advantage of the handheld LTP source is the ability to quickly interrogate a gaseous, liquid, or solid sample without requiring any setup time. A small, 7.4-V Li-polymer battery is able to sustain plasma for 2 h continuously, while the miniature helium cylinder supplies gas flow for approximately 8 continuous hours. Long-distance ion transfer was achieved for distances up to 1 m.

Validity and limitations of the Nidek NT-4000 non-contact tonometer: a clinical study.

Science.gov (United States)

Regine, Federico; Scuderi, Gian Luca; Cesareo, Massimo; Ricci, Federico; Cedrone, Claudio; Nucci, Carlo

2006-01-01

Using Goldmann applanation tonometry (GAT) as a gold standard, we evaluated the accuracy of Nidek NT-4000 pneumotonometry (NPT) in adults without corneal disease. Bland and Altman analysis of serial intra-ocular pressures (IOPs) measured with NPT and GAT in 10 healthy subjects revealed that the repeatability coefficients for the two methods were similar. NPT, GAT and ultrasonic pachymetry were then performed in 100 patients. Bland and Altman analysis showed that NPT yielded significantly higher readings than GAT [mean biases for right and left eye measurements were 1.37 mmHg (95% limits of agreement: -3.02-5.76) and 1.17 mmHg (95% limits of agreement: -2.76-5.11) respectively] and was more affected by corneal thickness variations. For detection of IOPs > or =21 mmHg, NPT displayed very high sensitivity (0.90) and good specificity (0.95). NPT may be useful in screening and clinical settings but borderline-high IOP readings should be confirmed with GAT.

Validity of maximal isometric knee extension strength measurements obtained via belt-stabilized hand-held dynamometry in healthy adults.

Science.gov (United States)

Ushiyama, Naoko; Kurobe, Yasushi; Momose, Kimito

2017-11-01

[Purpose] To determine the validity of knee extension muscle strength measurements using belt-stabilized hand-held dynamometry with and without body stabilization compared with the gold standard isokinetic dynamometry in healthy adults. [Subjects and Methods] Twenty-nine healthy adults (mean age, 21.3 years) were included. Study parameters involved right side measurements of maximal isometric knee extension strength obtained using belt-stabilized hand-held dynamometry with and without body stabilization and the gold standard. Measurements were performed in all subjects. [Results] A moderate correlation and fixed bias were found between measurements obtained using belt-stabilized hand-held dynamometry with body stabilization and the gold standard. No significant correlation and proportional bias were found between measurements obtained using belt-stabilized hand-held dynamometry without body stabilization and the gold standard. The strength identified using belt-stabilized hand-held dynamometry with body stabilization may not be commensurate with the maximum strength individuals can generate; however, it reflects such strength. In contrast, the strength identified using belt-stabilized hand-held dynamometry without body stabilization does not reflect the maximum strength. Therefore, a chair should be used to stabilize the body when performing measurements of maximal isometric knee extension strength using belt-stabilized hand-held dynamometry in healthy adults. [Conclusion] Belt-stabilized hand-held dynamometry with body stabilization is more convenient than the gold standard in clinical settings.

Handheld emissions detector (HED): overview and development

Science.gov (United States)

Valentino, George J.; Schimmel, David

2009-05-01

Nova Engineering, Cincinnati OH, a division of L-3 Communications (L-3 Nova), under the sponsorship of Program Manager Soldier Warrior (PM-SWAR), Fort Belvoir, VA, has developed a Soldier portable, light-weight, hand-held, geolocation sensor and processing system called the Handheld Emissions Detector (HED). The HED is a broadband custom receiver and processor that allows the user to easily sense, direction find, and locate a broad range of emitters in the user's surrounding area. Now in its second design iteration, the HED incorporates a set of COTS components that are complemented with L-3 Nova custom RF, power, digital, and mechanical components, plus custom embedded and application software. The HED user interfaces are designed to provide complex information in a readily-understandable form, thereby providing actionable results for operators. This paper provides, where possible, the top-level characteristics of the HED as well as the rationale behind its design philosophy along with its applications in both DOD and Commercial markets.

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

Science.gov (United States)

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 DSS scale was reliable, valid, and responsive. The scale can be used to guide future handheld DSS development and implementation.

Handheld Computers in Education: An Industry Perspective

Science.gov (United States)

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.

COMPARISON OF INTRAOCULAR PRESSURE MEASUREMENT WITH NON-CONTACT TONOMETRY AND APPLANATION TONOMETRY AMONG VARIOUS CENTRAL CORNEAL THICKNESS GROUPS

Directory of Open Access Journals (Sweden)

Radhakrishnan B

2018-02-01

Full Text Available BACKGROUND Glaucoma is the second leading cause of blindness worldwide. Intraocular Pressure (IOP is the only known modifiable risk factor that has been shown to delay progression in both ocular hypertension and glaucoma patients. Clinical measurement of IOP has undergone several technical advances from the initial digital tension measurements, through indentation tonometry, to applanation tonometry and non-contact tonometry. This study was done to compare the intraocular pressure (IOP measurements with Non Contact Tonometry (NCT and Goldmann Applanation tonometry (GAT and to compare NCT IOP and GAT IOP among various central corneal thickness (CCT groups. MATERIALS AND METHODS IOP measurements were done by NCT and then by GAT followed by CCT. All IOP readings were taken in the sitting position over fifteen minutes. NCT was performed before the GAT to avoid the known mild reduction of IOP by anterior chamber compression with GAT. RESULTS The study included 200 eyes of 100 patients. Mean age of the patients was 58.14 ± 11.7 years (range 35- 81 years. The study population consisted of 58 males and 42 females. The mean ± SD intraocular pressure measurements were 23.39 ± 4.6 mmHg and 22.41 ± 5.9 mmHg for NCT and GAT, respectively. The difference between the NCT and GAT IOP was 0.98 ± 4.7 mm Hg. Mean CCT of the study group was 545.74 ± 38.23 microns. The IOP measured with both GAT and NCT showed no significant change with increasing CCT. The difference between the means increases with increasing CCT upto 600 microns. At lower IOPs ≤ 20 mm Hg, GAT measures are higher than NCT and this relationship is reversed at high IOPs. CONCLUSION Intraocular pressure measurement by NCT was consistently higher than GAT. There was a tendency for NCT to underestimate IOP at lower ranges and overestimates IOP at higher ranges. By applying appropriate correction factor for CCT, Noncontact tonometry could be used as a good screening tool for glaucoma evaluation.

Handheld FRET-Aptamer Sensor for Water Safety, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Operational Technologies Corporation (OpTech) proposes to expand its current NASA Phase 2 SBIR handheld fluorometer and bone marker fluorescence resonance energy...

SAFARI 2000 Atmospheric Aerosol Measurements, Hand-held Hazemeters, Zambia

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: In conjunction with the AERONET (AErosol RObotic NETwork) participation in SAFARI 2000, the USDA Forest Service deployed handheld hazemeters in western...

SAFARI 2000 Atmospheric Aerosol Measurements, Hand-held Hazemeters, Zambia

Data.gov (United States)

National Aeronautics and Space Administration — In conjunction with the AERONET (AErosol RObotic NETwork) participation in SAFARI 2000, the USDA Forest Service deployed handheld hazemeters in western Zambia from...

An Intelligent Hand-Held Microsurgical Instrument for Improved Accuracy

National Research Council Canada - National Science Library

Ang, Wei

2001-01-01

This paper presents the development and initial experimental results of the first prototype of Micron, an active hand-held instrument to sense and compensate physiological tremor and other unwanted...

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

Science.gov (United States)

2010-02-24

... Communications System Server Software, Wireless Handheld Devices and Battery Packs; Notice of Investigation... within the United States after importation of certain wireless communications system server software... certain wireless communications system server software, wireless handheld devices or battery packs that...

The impact of legislation in Ireland on handheld mobile phone use by drivers.

LENUS (Irish Health Repository)

O'Meara, M

2008-01-01

Under the Road Traffic Act, 2006 handheld mobile phone use whilst driving is an offence liable to a fine and penalty points. The aim of this study was to determine whether there has been a change in driver behaviour following the introduction of this legislation. This study found that 2.3% of drivers were still using a handheld mobile phone.

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

Science.gov (United States)

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...

Criteria for a comparative assessment on handheld gamma-ray measurement tools

International Nuclear Information System (INIS)

Feichtinger, J.; Schwaiger, M.; Schmitzer, C.; Kindl, P.

2001-01-01

Full text: The radionuclide laboratories at the Austrian Research Centres Seibersdorf are strongly involved in radiation protection of public and employees as well as in environmental monitoring with special concern to gamma spectrometric measurements. Hence, field measurements and therefore the subject of hand-held measurement devices is a topic of main interest. Taking into consideration, that these hand-held measurement tool are further used in critical and sensitive operations, as for example by the IAEA Safeguards or by CTBTO On-Site inspectors, a standard for characterising these gamma measurement tools seems to be sound as necessary. The poster presents a set of technical criteria as well as limiting values, which allows an objective comparison of hand-held measurement devices. The criteria can be divided into three individual parts: radiometric characteristics, ergonomics and usability in field operations. The main criteria for testing the radiometry performance of hand-held measurement devices are sensitivity, efficiency, energy response, energy resolution and nuclide identification or not identification (if necessary), detection probability, dose rate indication, uncertainty, etc. The ergonomic test contains as dominating parts handling and quality of the manual. To evaluate the applicability in field operations different environmental conditions (e.g. light conditions, temperature range, moisture...) as well as battery lifetime and weight should be taken into account. These criteria may vary in dependence of the requirements or limitations given by various external conditions, but still a standard to evaluate and will give the opportunity to provide an objective comparison. (author)

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

Science.gov (United States)

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…

Hand-held cell phone use while driving legislation and observed driver behavior among population sub-groups in the United States.

Science.gov (United States)

Rudisill, Toni M; Zhu, Motao

2017-05-12

Cell phone use behaviors are known to vary across demographic sub-groups and geographic locations. This study examined whether universal hand-held calling while driving bans were associated with lower road-side observed hand-held cell phone conversations across drivers of different ages (16-24, 25-59, ≥60 years), sexes, races (White, African American, or other), ruralities (suburban, rural, or urban), and regions (Northeast, Midwest, South, and West). Data from the 2008-2013 National Occupant Protection Use Survey were merged with states' cell phone use while driving legislation. The exposure was presence of a universal hand-held cell phone ban at time of observation. Logistic regression was used to assess the odds of drivers having a hand-held cell phone conversation. Sub-groups differences were assessed using models with interaction terms. When universal hand-held cell phone bans were effective, hand-held cell phone conversations were lower across all driver demographic sub-groups and regions. Sub-group differences existed among the sexes (p-value, phone bans, the adjusted odds ratio (aOR) of a driver hand-held phone conversation was 0.34 [95% confidence interval (CI): 0.28, 0.41] for females versus 0.47 (CI 0.40, 0.55) for males and 0.31 (CI 0.25, 0.38) for drivers in Western states compared to 0.47 (CI 0.30, 0.72) in the Northeast and 0.50 (CI 0.38, 0.66) in the South. The presence of universal hand-held cell phone bans were associated lower hand-held cell phone conversations across all driver sub-groups and regions. Hand-held phone conversations were particularly lower among female drivers and those from Western states when these bans were in effect. Public health interventions concerning hand-held cell phone use while driving could reasonably target all drivers.

Accentuated Factors of Handheld Computing

DEFF Research Database (Denmark)

Andersson, Bo; Henningsson, Stefan

The recent years of rapid development of mobile technologies creates opportunities for new user-groups in the mobile workforce to take advantage of in-formation systems (IS). However, to apprehend and harness these opportunities for mobile IS it is crucial to fully understand the user group and t......, these two steps develop the framework towards a theoretical contribution as theory for describing handheld computing from a designer’s perspective. Thirteen semi-structured interviews were made and the tentative framework was elaborated and confirmed....

Hand-held cell phone use while driving legislation and observed driver behavior among population sub-groups in the United States

Directory of Open Access Journals (Sweden)

Toni M. Rudisill

2017-05-01

Full Text Available Abstract Background Cell phone use behaviors are known to vary across demographic sub-groups and geographic locations. This study examined whether universal hand-held calling while driving bans were associated with lower road-side observed hand-held cell phone conversations across drivers of different ages (16–24, 25–59, ≥60 years, sexes, races (White, African American, or other, ruralities (suburban, rural, or urban, and regions (Northeast, Midwest, South, and West. Methods Data from the 2008–2013 National Occupant Protection Use Survey were merged with states’ cell phone use while driving legislation. The exposure was presence of a universal hand-held cell phone ban at time of observation. Logistic regression was used to assess the odds of drivers having a hand-held cell phone conversation. Sub-groups differences were assessed using models with interaction terms. Results When universal hand-held cell phone bans were effective, hand-held cell phone conversations were lower across all driver demographic sub-groups and regions. Sub-group differences existed among the sexes (p-value, <0.0001 and regions (p-value, 0.0003. Compared to states without universal hand-held cell phone bans, the adjusted odds ratio (aOR of a driver hand-held phone conversation was 0.34 [95% confidence interval (CI: 0.28, 0.41] for females versus 0.47 (CI 0.40, 0.55 for males and 0.31 (CI 0.25, 0.38 for drivers in Western states compared to 0.47 (CI 0.30, 0.72 in the Northeast and 0.50 (CI 0.38, 0.66 in the South. Conclusions The presence of universal hand-held cell phone bans were associated lower hand-held cell phone conversations across all driver sub-groups and regions. Hand-held phone conversations were particularly lower among female drivers and those from Western states when these bans were in effect. Public health interventions concerning hand-held cell phone use while driving could reasonably target all drivers.

Acute pain management efficiency improves with point-of-care handheld electronic billing system.

Science.gov (United States)

Fahy, Brenda G

2009-02-01

Technology advances continue to impact patient care and physician workflow. To enable more efficient performance of billing activities, a point-of-care (POC) handheld computer technology replaced a paper-based system on an acute pain management service. Using a handheld personal digital assistant (PDA) and software from MDeverywhere (MDe, MDeverywhere, Long Island, NY), we performed a 1-yr prospective observational study of an anesthesiology acute pain management service billings and collections. Seventeen anesthesiologists providing billable acute pain services were trained and entered their charges on a PDA. Twelve months of data, just before electronic implementation (pre-elec), were compared to a 12-m period after implementation (post-elec). The total charges were 4883 for 890 patients pre-elec and 5368 for 1128 patients post-elec. With adoption of handheld billing, the charge lag days decreased from 29.3 to 7.0 (P billing using PDAs to replace a paper-based billing system improved the collection rate and decreased the number of charge lag days with a positive return on investment. The handheld PDA billing system provided POC support for physicians during their daily clinical (e.g., patient locations, rounding lists) and billing activities, improving workflow.

Epilepsy Forewarning Using A Hand-Held Device

Energy Technology Data Exchange (ETDEWEB)

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.

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

Science.gov (United States)

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.

Evaluation of an enclosed ultraviolet-C radiation device for decontamination of mobile handheld devices.

Science.gov (United States)

Mathew, J Itty; Cadnum, Jennifer L; Sankar, Thriveen; Jencson, Annette L; Kundrapu, Sirisha; Donskey, Curtis J

2016-06-01

Mobile handheld devices used in health care settings may become contaminated with health care-associated pathogens. We demonstrated that an enclosed ultraviolet-C radiation device was effective in rapidly reducing methicillin-resistant Staphylococcus aureus, and with longer exposure times, Clostridium difficile spores, on glass slides and reducing contamination on in-use mobile handheld devices. Published by Elsevier Inc.

Agreement Between an Automated Volume Breast Scanner and Handheld Ultrasound for Diagnostic Breast Examinations.

Science.gov (United States)

Barr, Richard G; DeVita, Robert; Destounis, Stamatia; Manzoni, Federica; De Silvestri, Annalisa; Tinelli, Carmine

2017-10-01

To compare the agreement and interobserver variability of diagnostic handheld ultrasound (US) and a single volume on an automated breast volume scanner (ABVS) and to determine whether there was a significant difference if the ABVS was used by a sonographer or mammographic technologist. Ninety patients scheduled for diagnostic US examinations were randomized to either handheld US or the ABVS first. The AVBS was randomized between a sonographer and a mammographic technologist performing the study. The studies were blinded, randomized, and read by 2 radiologists. The lesion with the highest Breast Imaging Reporting and Data System (BI-RADS) score was used in the analysis. Final diagnoses were made by core biopsy or follow-up for 2 years. Lesions included 9 malignant and 81 benign. The 90 patients had a mean age ± SD of 53.1 ± 16.3 years. The κ value for agreement between the ABVS and handheld US was 0.831 (95% confidence interval, 0.744-0.925), whereas the global agreement for a 7-point BI-RADS score was 0.488 (0.372-0.560). The agreement between the ABVS and handheld US was nearly the same when the ABVS was used by a mammographic technologist (κ = 0.858 [0.723-0.963]) or sonographer (κ = 0.803 [0.596-1.000]; P = .47). The areas under the receiver operating characteristic curves for characterization by the ABVS were 0.91 (0.84-0.96) for reader 1 and 0.91 (0.83-0.96) for reader 2; those for handheld US were 0.91 (0.84-0.96) for reader 1 and 0.83 (0.74-0.90) for reader 2, with no statistical difference. The agreement based on pathologic images was κ = 0.831 (0.718-0.944); for handheld US, κ = 0.795 (0.623-0.967); and for the AVBS, κ = 0.869 (0.725-1.000). Performing a single-view diagnostic ABVS examination has good agreement with a handheld diagnostic US workup. There is no difference if the ABVS is used by a sonographer or mammographic technologist. © 2017 by the American Institute of Ultrasound in Medicine.

Leakage and scattered radiation from hand-held dental x-ray unit

International Nuclear Information System (INIS)

Kim, Eun Kyung

2007-01-01

To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR ΙΙΙ was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of hand-held dental X-ray unit were 70 kVp, 3 mA , 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. The mean dose at the hand level when human skull DXTTR ΙΙΙ was exposed with portable X-ray unit 6.39 μGy, and the mean dose with fixed X-ray unit 3.03 μGy (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was 2.97 μGy and with fixed X-ray unit the mean dose was 0.68 μGy (p<0.01). The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography

Leakage and scattered radiation from hand-held dental x-ray unit

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Kyung [Dankook Univ. School of Dentistry, Seoul (Korea, Republic of)

2007-06-15

To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR {iota}{iota}{iota} was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of hand-held dental X-ray unit were 70 kVp, 3 mA , 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. The mean dose at the hand level when human skull DXTTR {iota}{iota}{iota} was exposed with portable X-ray unit 6.39 {mu}Gy, and the mean dose with fixed X-ray unit 3.03 {mu}Gy (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was 2.97 {mu}Gy and with fixed X-ray unit the mean dose was 0.68 {mu}Gy (p<0.01). The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.

Handheld computers for self-administered sensitive data collection: A comparative study in Peru

Directory of Open Access Journals (Sweden)

Hughes James P

2008-03-01

Full Text Available Abstract Background Low-cost handheld computers (PDA potentially represent an efficient tool for collecting sensitive data in surveys. The goal of this study is to evaluate the quality of sexual behavior data collected with handheld computers in comparison with paper-based questionnaires. Methods A PDA-based program for data collection was developed using Open-Source tools. In two cross-sectional studies, we compared data concerning sexual behavior collected with paper forms to data collected with PDA-based forms in Ancon (Lima. Results The first study enrolled 200 participants (18–29 years. General agreement between data collected with paper format and handheld computers was 86%. Categorical variables agreement was between 70.5% and 98.5% (Kappa: 0.43–0.86 while numeric variables agreement was between 57.1% and 79.8% (Spearman: 0.76–0.95. Agreement and correlation were higher in those who had completed at least high school than those with less education. The second study enrolled 198 participants. Rates of responses to sensitive questions were similar between both kinds of questionnaires. However, the number of inconsistencies (p = 0.0001 and missing values (p = 0.001 were significantly higher in paper questionnaires. Conclusion This study showed the value of the use of handheld computers for collecting sensitive data, since a high level of agreement between paper and PDA responses was reached. In addition, a lower number of inconsistencies and missing values were found with the PDA-based system. This study has demonstrated that it is feasible to develop a low-cost application for handheld computers, and that PDAs are feasible alternatives for collecting field data in a developing country.

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

Energy Technology Data Exchange (ETDEWEB)

Aldrian, Alexia, E-mail: alexia.aldrian@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Ledersteger, Alfred, E-mail: a.ledersteger@saubermacher.at [Saubermacher Dienstleistungs AG, Hans-Roth-Straße 1, 8073 Feldkirchen bei Graz (Austria); Pomberger, Roland, E-mail: roland.pomberger@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria)

2015-02-15

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 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 50,000 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.

Human Handheld-Device Interaction : An Adaptive User Interface

NARCIS (Netherlands)

Fitrianie, S.

2010-01-01

The move to smaller, lighter and more powerful (mobile) handheld devices, whe-ther PDAs or smart-phones, looks like a trend that is building up speed. With numerous embedded technologies and wireless connectivity, the drift opens up unlimited opportunities in daily activities that are both more

The availability of relatively cheap hand-held Global Positioning ...

African Journals Online (AJOL)

spamer

conditions, so the approach failed to produce results ... Hand-held Global Positioning System (GPS) receivers provide opportunities for detailed and rapid mapping of features ..... TICKELL, W. L. N. 1968 — The biology of the great albatrosses,.

Hand-held electronic data collection and procedure environment

International Nuclear Information System (INIS)

Kennedy, E.; Doniz, K.

1996-01-01

As part of a CANDU Owners Group project, AECL has developed a hand-held electronic data collection and procedure environment. Integral to this environment is the C omputerized Procedure Engine . The development of the CPE allows operators, maintainers, and technical support staff to execute virtually any type of station procedure on a general-purpose PC-compatible hand-held computer. There are several advantages to using the computerized procedures: less paper use and handling, reduction in human error, reduction in rework in the field, an increase in procedural compliance, and immediate availability of data to download to databases and plant information systems. The paper describes: the advantages of using computerized procedures, why early forms of computerized procedures were inadequate, the features that the C omputerized Procedure Engine o ffers to the user, the streamlined life cycle of a computerized procedure, and field experience. The paper concludes that computerized procedures are ready for pilot applications at stations. (author)

Measuring thyroid uptake with hand-held radiation monitors

International Nuclear Information System (INIS)

Deschamps, M.

1987-04-01

With the use of Iodine 123, 125 and 131 and some compounds of Technetium-99 m, a fraction of the isotopes can be trapped in the thyroid of the technicians. We used the hand-held radiation contamination or survey meters of the nine (9) Nuclear medicine departments we visited to see if they were adequate for the evaluation of thyroid uptake of the users. Measurements on a neck-phanton helped us to determine a minimum detectable activity for each isotope. We were then able to check if the measurements of investigations and action levels were possible. None of the hand-held radiation monitors are completely satisfactory for the measure of thyroid uptake of the user. We discuss a class of equipment capable of measuring radiation emissions at the investigation level. Measurement at the action level is possible with meters having scintillation or proportional probes but none of them permits the discrimination in energy required for a quantitative evaluation of the radioisotopes used

Distribution of IOP measured with an air puff tonometer in a young population.

Science.gov (United States)

Hashemi, Hassan; Khabazkhoob, Mehdi; Nabovati, Payam; Yazdani, Negareh; Ostadimoghaddam, Hadi; Shiralivand, Ehsan; Derakhshan, Akbar; Yekta, AbbasAli

2018-03-01

To determine the normal range of intraocular pressure (IOP) in the young and its association with certain corneal parameters using a non-contact device. Subjects were selected from students of Mashhad University of Medical Sciences through stratified sampling. All participants had visual acuity testing, corneal imaging, a comprehensive slit-lamp examination by an ophthalmologist, and IOP measurement using a non-contact air-puff tonometer. Of the 1280 invitees, 1073 (83.8%) participated, and 1027 were eligible. Mean IOP was 16.38 mmHg [95% confidence interval (CI): 16.22-16.53] in the total sample, 16.14 mmHg (95% CI: 15.84-16.45) in men, and 16.48 mmHg (95% CI: 16.31-16.66) in women. There was a significant IOP difference between myopes and emmetropes ( P  = 0.031). Based on the multiple linear regression model, IOP associated directly with age and central corneal thickness (CCT), and inversely with corneal diameter, spherical equivalent (SE), and keratoconus. Based on standardized coefficients of the regression model, CCT and SE had the strongest association with IOP. In the present study, we demonstrated the IOP distribution in a young population using a non-contact method. CCT and SE were strongly associated with IOP.

Handheld Universal Diagnostic Sensor

Science.gov (United States)

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.

Application of Handheld Laser-Induced Breakdown Spectroscopy (LIBS) to Geochemical Analysis.

Science.gov (United States)

Connors, Brendan; Somers, Andrew; Day, David

2016-05-01

While laser-induced breakdown spectroscopy (LIBS) has been in use for decades, only within the last two years has technology progressed to the point of enabling true handheld, self-contained instruments. Several instruments are now commercially available with a range of capabilities and features. In this paper, the SciAps Z-500 handheld LIBS instrument functionality and sub-systems are reviewed. Several assayed geochemical sample sets, including igneous rocks and soils, are investigated. Calibration data are presented for multiple elements of interest along with examples of elemental mapping in heterogeneous samples. Sample preparation and the data collection method from multiple locations and data analysis are discussed. © The Author(s) 2016.

Exploring streamwater mixing dynamics via handheld thermal infrared imagery

NARCIS (Netherlands)

Antonelli, Marta; Klaus, Julian; Smettem, Keith; Teuling, Ryan; Pfister, Laurent

2017-01-01

Stream confluences are important hotspots of aquatic ecological processes. Water mixing dynamics at stream confluences influence physio-chemical characteristics of the stream as well as sediment mobilisation and pollutant dispersal. In this study, we investigated the potential for handheld

Monitoring invasive plants using hand-held GIS technology

Science.gov (United States)

Theresa M. Mau-Crimmins; Barron J. Orr

2005-01-01

Successful control of invasive species requires a clear picture of the spatial extent of infestations. The latest mapping technology involves coupling global position systems and handheld computers running geographic information systems software in the field. A series of workshops applying this technology to mapping weeds was developed and presented to Weed Management...

Accuracy of Handheld Blood Glucose Meters at High Altitude

NARCIS (Netherlands)

de Mol, Pieter; Krabbe, Hans G.; de Vries, Suzanna T.; Fokkert, Marion J.; Dikkeschei, Bert D.; Rienks, Rienk; Bilo, Karin M.; Bilo, Henk J. G.

2010-01-01

Background: Due to increasing numbers of people with diabetes taking part in extreme sports (e. g., high-altitude trekking), reliable handheld blood glucose meters (BGMs) are necessary. Accurate blood glucose measurement under extreme conditions is paramount for safe recreation at altitude. Prior

A hand-held robotic device for peripheral intravenous catheterization.

Science.gov (United States)

Cheng, Zhuoqi; Davies, Brian L; Caldwell, Darwin G; Barresi, Giacinto; Xu, Qinqi; Mattos, Leonardo S

2017-12-01

Intravenous catheterization is frequently required for numerous medical treatments. However, this process is characterized by a high failure rate, especially when performed on difficult patients such as newborns and infants. Very young patients have small veins, and that increases the chances of accidentally puncturing the catheterization needle directly through them. In this article, we present the design, development and experimental evaluation of a novel hand-held robotic device for improving the process of peripheral intravenous catheterization by facilitating the needle insertion procedure. To our knowledge, this design is the first hand-held robotic device for assisting in the catheterization insertion task. Compared to the other available technologies, it has several unique advantages such as being compact, low-cost and able to reliably detect venipuncture. The system is equipped with an electrical impedance sensor at the tip of the catheterization needle, which provides real-time measurements used to supervise and control the catheter insertion process. This allows the robotic system to precisely position the needle within the lumen of the target vein, leading to enhanced catheterization success rate. Experiments conducted to evaluate the device demonstrated that it is also effective to deskill the task. Naïve subjects achieved an average catheterization success rate of 88% on a 1.5 mm phantom vessel with the robotic device versus 12% with the traditional unassisted system. The results of this work prove the feasibility of a hand-held assistive robotic device for intravenous catheterization and show that such device has the potential to greatly improve the success rate of these difficult operations.

Neurosurgery contact handheld probe based on sapphire shaped crystal

Science.gov (United States)

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.

A handheld support system to facilitate stereological measurements and mapping of branching structures

DEFF Research Database (Denmark)

Gardi, J.E.; Wulfsohn, Dvora-Laiô; Nyengaard, J.R.

2007-01-01

specifications, software and Graphical User Interface (GUI) development, functionality and application of the handheld system using four examples: (1) sampling monkey lung bronchioles for estimation of diameter and wall thickness (2) sampling rat kidney for estimating number of arteries and arterioles......‘BranchSampler' is a system for computer-assisted manual stereology written for handheld devices running Windows CE. The system has been designed specifically to streamline data collection and optimize sampling of tree-like branching structures, with particular aims of reducing user errors, saving...

Experimental Feasibility Study of Estimation of the Normalized Central Blood Pressure Waveform from Radial Photoplethysmogram

Directory of Open Access Journals (Sweden)

Edmond Zahedi

2015-01-01

Full Text Available The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN from the radial photoplethysmogram (PPG is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN. A total of fifteen second-order autoregressive models with exogenous input were investigated using system identification techniques. Among these 15 models, the model producing the lowest coefficient of variation (CV of the fitness during the five days was selected as the reference model. Results show that the proposed model is able to faithfully reproduce CBPN (mean fitness = 85.2% ± 2.5% from the radial PPG for all 15 segments during the five recording days. The low CV value of 3.35% suggests a stable model valid for different recording days.

Imaging Emission Spectra with Handheld and Cellphone Cameras

Science.gov (United States)

Sitar, David

2012-01-01

As point-and-shoot digital camera technology advances it is becoming easier to image spectra in a laboratory setting on a shoestring budget and get immediate results. With this in mind, I wanted to test three cameras to see how their results would differ. Two undergraduate physics students and I used one handheld 7.1 megapixel (MP) digital Cannon…

Diagnostic efficacy of handheld devices for emergency radiologic consultation.

LENUS (Irish Health Repository)

Toomey, Rachel J

2010-02-01

Orthopedic injury and intracranial hemorrhage are commonly encountered in emergency radiology, and accurate and timely diagnosis is important. The purpose of this study was to determine whether the diagnostic accuracy of handheld computing devices is comparable to that of monitors that might be used in emergency teleconsultation.

Octopus: embracing the energy efficiency of handheld multimedia computers

NARCIS (Netherlands)

Havinga, Paul J.M.; Smit, Gerardus Johannes Maria

1999-01-01

In the MOBY DICK project we develop and define the architecture of a new generation of mobile hand-held computers called Mobile Digital Companions. The Companions must meet several major requirements: high performance, energy efficient, a notion of Quality of Service (QoS), small size, and low

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

Directory of Open Access Journals (Sweden)

Fleming Lora E

2011-04-01

Full Text Available Abstract Background 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. Methods 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. Results 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. Conclusions Handheld devices, which are relatively inexpensive, minimize survey response error, and allow for easy storage of data

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

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

Janson C

2006-04-01

Full Text Available Abstract 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

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

Science.gov (United States)

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

Science.gov (United States)

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.

Interactive topology optimization on hand-held devices

DEFF Research Database (Denmark)

Aage, Niels; Nobel-Jørgensen, Morten; Andreasen, Casper Schousboe

2013-01-01

This paper presents an interactive topology optimization application designed for hand-held devices running iOS or Android. The TopOpt app solves the 2D minimum compliance problem with interactive control of load and support positions as well as volume fraction. Thus, it is possible to change......OS devices from the Apple App Store, at Google Play for the Android platform, and a web-version can be run from www.topopt.dtu.dk....

Hand-held and automated breast ultrasound

International Nuclear Information System (INIS)

Bassett, L.W.; Gold, R.H.; Kimme-Smith, C.

1985-01-01

The book is a guide for physicians and technologists who use US as an adjunct to mammography; it carefully outlines the pros and cons of US of the breast and its role in the diagnosis of benign and malignant diseases. After an introduction that discusses the philosophy of breast US, the chapters cover the physics of US and instrumentation (both hand-held transducers as well as automated water path scanners), then proceed to a discussion of the normal breast. Sections on benign disorders, malignant lesions, and pitfalls of diagnosis are followed by quiz cases

Technology-enabled division of labour: the use of handhelds

NARCIS (Netherlands)

Benders, J.G.J.M.; Schouteten, R.L.J.; Ruijsscher, C. de

2012-01-01

Using the task pool model and data from 15 establishments in the Dutch hospitality industry, this study shows how and why applying handhelds affects the division of labour. These devices allow to split the waiters' jobs into separate tasks which tend to be combined into two separate "sub jobs": the

Technology-enabled division of labour : The use of handhelds

NARCIS (Netherlands)

Benders, J.G.J.M.; Schouteten, R.; de Ruijsscher, C.

2012-01-01

Using the task pool model and data from 15 establishments in the Dutch hospitality industry, this study shows how and why applying handhelds affects the division of labour. These devices allow to split the waiters' jobs into separate tasks which tend to be combined into two separate "sub jobs": the

Intraocular pressure measurement with the noncontact tonometer through soft contact lenses.

Science.gov (United States)

Liu, Yi-Chun; Huang, Jehn-Yu; Wang, I-Jong; Hu, Fung-Rong; Hou, Yu-Chih

2011-03-01

To assess the accuracy of measuring intraocular pressure (IOP) through a soft contact lens (SCL) with different refractive powers using a noncontact tonometer (NCT). Thirty-two healthy adult volunteers free of glaucoma or corneal disease participated in this study. IOP was measured in the right eyes without SCLs and with different lens powers, from -3.0 to -12.0 D as measured by NCT. IOP of the left eyes was also measured, as an internal control. Corneal curvature was measured in both eyes using an autokeratometer. Sixteen volunteers wore one brand of SCL (group A) and the other 16 wore a different brand, with 2 different curvatures (groups B and C). Statistical data were analyzed by SPSS using the Wilcoxon signed rank test for comparison of IOP readings and multiple linear regression analysis for the relationship among power of contact lenses, corneal power, and difference in IOP measurements. The difference in mean IOP between eyes without lenses and those with lenses was statistically significant in lens with -6.0 D and below in all 3 groups. The decrease in IOP significantly correlated with the refractive power of contact lenses in all 3 groups. The difference in IOP measurements was influenced by the mean K in group A but not in group B or C. There was no statistically significant difference in the IOP measurements in the left eyes or in the mean K between the right and left eyes. IOP measurement through myopic SCLs by NCT may be inaccurate and tends toward underestimation, especially in high myopic lenses. A strong relationship exists between IOP reduction and myopic lens power.

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

Science.gov (United States)

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.

A hand-held beta imaging probe for FDG.

Science.gov (United States)

Singh, Bipin; Stack, Brendan C; Thacker, Samta; Gaysinskiy, Valeriy; Bartel, Twyla; Lowe, Val; Cool, Steven; Entine, Gerald; Nagarkar, Vivek

2013-04-01

Advances in radiopharmaceuticals and clinical understanding have escalated the use of intraoperative gamma probes in surgery. However, most probes on the market are non-imaging gamma probes that suffer from the lack of ancillary information of the surveyed tissue area. We have developed a novel, hand-held digital Imaging Beta Probe™ (IBP™) to be used in surgery in conjunction with beta-emitting radiopharmaceuticals such as (18)FDG, (131)I and (32)P for real-time imaging of a surveyed area with higher spatial resolution and sensitivity and greater convenience than existing instruments. We describe the design and validation of a hand-held beta probe intended to be used as a visual mapping device to locate and confirm excision of (18)FDG-avid primary tumors and metastases in an animal model. We have demonstrated a device which can generate beta images from (18)FDG avid lesions in an animal model. It is feasible to image beta irradiation in animal models of cancer given (18)FDG. This technology may be applied to clinical mapping of tumors and/or their metastases in the operating room. Visual image depiction of malignancy may aid the surgeon in localization and excision of lesions of interest.

Video Browsing on Handheld Devices

Science.gov (United States)

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.

Web-Based Spatial Training Using Handheld Touch Screen Devices

Science.gov (United States)

Martin-Dorta, Norena; Saorin, Jose Luis; Contero, Manuel

2011-01-01

This paper attempts to harness the opportunities for mobility and the new user interfaces that handheld touch screen devices offer, in a non-formal learning context, with a view to developing spatial ability. This research has addressed two objectives: first, analyzing the effects that training can have on spatial visualisation using the…

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

Science.gov (United States)

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.

Jump Training in Youth Soccer Players: Effects of Haltere Type Handheld Loading.

Science.gov (United States)

Rosas, F; Ramirez-Campillo, R; Diaz, D; Abad-Colil, F; Martinez-Salazar, C; Caniuqueo, A; Cañas-Jamet, R; Loturco, I; Nakamura, F Y; McKenzie, C; Gonzalez-Rivera, J; Sanchez-Sanchez, J; Izquierdo, M

2016-12-01

The aim of this study was to compare the effects of a jump training program, with or without haltere type handheld loading, on maximal intensity exercise performance. Youth soccer players (12.1±2.2 y) were assigned to either a jump training group (JG, n=21), a jump training group plus haltere type handheld loading (LJG, n=21), or a control group following only soccer training (CG, n=21). Athletes were evaluated for maximal-intensity performance measures before and after 6 weeks of training, during an in-season training period. The CG achieved a significant change in maximal kicking velocity only (ES=0.11-0.20). Both jump training groups improved in right leg (ES=0.28-0.45) and left leg horizontal countermovement jump with arms (ES=0.32-0.47), horizontal countermovement jump with arms (ES=0.28-0.37), vertical countermovement jump with arms (ES=0.26), 20-cm drop jump reactive strength index (ES=0.20-0.37), and maximal kicking velocity (ES=0.27-0.34). Nevertheless, compared to the CG, only the LJG exhibited greater improvements in all performance tests. Therefore, haltere type handheld loading further enhances performance adaptations during jump training in youth soccer players. © Georg Thieme Verlag KG Stuttgart · New York.

Application of Handheld Tele-ECG for Health Care Delivery in Rural India

Directory of Open Access Journals (Sweden)

Meenu Singh

2014-01-01

Full Text Available Telemonitoring is a medical practice that involves remotely monitoring patients who are not at the same location as the health care provider. The purpose of our study was to use handheld tele-electrocardiogram (ECG developed by Bhabha Atomic Research Center (BARC to identify heart conditions in the rural underserved population where the doctor-patient ratio is low and access to health care is difficult. The objective of our study was clinical validation of handheld tele-ECG as a screening tool for evaluation of cardiac diseases in the rural population. ECG was obtained in 450 individuals (mean age 31.49 ± 20.058 residing in the periphery of Chandigarh, India, from April 2011 to March 2013, using the handheld tele-ECG machine. The data were then transmitted to physicians in Postgraduate Institute of Medical Education and Research (PGIMER, Chandigarh, for their expert opinion. ECG was interpreted as normal in 70% individuals. Left ventricular hypertrophy (9.3% was the commonest abnormality followed closely by old myocardial infarction (5.3%. Patient satisfaction was reported to be ~95%. Thus, it can be safely concluded that tele-ECG is a portable, cost-effective, and convenient tool for diagnosis and monitoring of heart diseases and thus improves quality and accessibility, especially in rural areas.

Towards Vision-Based Control of a Handheld Micromanipulator for Retinal Cannulation in an Eyeball Phantom

Science.gov (United States)

Becker, Brian C.; Yang, Sungwook; MacLachlan, Robert A.; Riviere, Cameron N.

2012-01-01

Injecting clot-busting drugs such as t-PA into tiny vessels thinner than a human hair in the eye is a challenging procedure, especially since the vessels lie directly on top of the delicate and easily damaged retina. Various robotic aids have been proposed with the goal of increasing safety by removing tremor and increasing precision with motion scaling. We have developed a fully handheld micromanipulator, Micron, that has demonstrated reduced tremor when cannulating porcine retinal veins in an “open sky” scenario. In this paper, we present work towards handheld robotic cannulation with the goal of vision-based virtual fixtures guiding the tip of the cannula to the vessel. Using a realistic eyeball phantom, we address sclerotomy constraints, eye movement, and non-planar retina. Preliminary results indicate a handheld micromanipulator aided by visual control is a promising solution to retinal vessel occlusion. PMID:24649479

MEMS-based handheld fourier domain Doppler optical coherence tomography for intraoperative microvascular anastomosis imaging.

Directory of Open Access Journals (Sweden)

Yong Huang

Full Text Available 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.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.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.A miniature handheld OCT imager that can be used for intraoperative evaluation of

Ultra-compact swept-source optical coherence tomography handheld probe with motorized focus adjustment (Conference Presentation)

Science.gov (United States)

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

2017-02-01

Handheld optical coherence tomography (OCT) systems facilitate imaging of young children, bedridden subjects, and those with less stable fixation. Smaller and lighter OCT probes allow for more efficient imaging and reduced operator fatigue, which is critical for prolonged use in either the operating room or neonatal intensive care unit. In addition to size and weight, the imaging speed, image quality, field of view, resolution, and focus correction capability are critical parameters that determine the clinical utility of a handheld probe. Here, we describe an ultra-compact swept source (SS) OCT handheld probe weighing only 211 g (half the weight of the next lightest handheld SSOCT probe in the literature) with 20.1 µm lateral resolution, 7 µm axial resolution, 102 dB peak sensitivity, a 27° x 23° field of view, and motorized focus adjustment for refraction correction between -10 to +16 D. A 2D microelectromechanical systems (MEMS) scanner, a converging beam-at-scanner telescope configuration, and an optical design employing 6 different custom optics were used to minimize device size and weight while achieving diffraction limited performance throughout the system's field of view. Custom graphics processing unit (GPU)-accelerated software was used to provide real-time display of OCT B-scans and volumes. Retinal images were acquired from adult volunteers to demonstrate imaging performance.

Measurement of intraocular pressure with pressure phosphene tonometry in children.

Science.gov (United States)

Fan, Dorothy S P; Chiu, Thomas Y H; Congdon, Nathan; Chan, Jeffrey C W; Cheung, Eva Y Y; Lam, Dennis S C

2011-01-01

To study the accuracy and acceptability of intraocular pressure (IOP) measurement by the pressure phosphene tonometer, non-contact tonometer, and Goldmann tonometer in children. Fifty children (5 to 14 years old) participated in this prospective comparative study. IOP was measured with the pressure phosphene tonometer, non-contact tonometer, and Goldmann tonometer by three different examiners who were masked to the results. The children were also asked to grade the degree of discomfort from 0 to 5 (0 = no discomfort; 5 = most discomfort). The mean IOPs measured by the Goldmann tonometer, pressure phosphene tonometer, and non-contact tonometer were 15.9 mm Hg (standard deviation [SD]: = 5.5 mm Hg; range: 10 to 36 mm Hg), 16.0 mm Hg (SD: 2.9 mm Hg; range: 12 to 25 mm Hg), and 15.7 mm Hg (SD = 5.1 mm Hg; range: 8 to 32 mm Hg), respectively (P = .722). The mean difference between pressure phosphene tonometer and Goldmann tonometer readings was 2.9 mm Hg and that between non-contact tonometer and Goldmann tonometer readings was 2.1 mm Hg. The 95% confidence interval of the mean difference between pressure phosphene tonometer and Goldmann tonometer readings was -1.07 and 1.19, and that between non-contact tonometer and Goldmann tonometer readings was -1.07 and 0.53. The mean discomfort ratings for the pressure phosphene tonometer, non-contact tonometer, and Goldmann tonometer were 0.6, 2.0, and 2.3, respectively (P tonometer was less accurate than the non-contact tonometer compared with Goldmann tonometer, it gave a reasonably close estimate and had a high specificity of raised IOP. In addition, measurement by the pressure phosphene tonometer is most acceptable to children. The pressure phosphene tonometer can be considered as an alternative method of IOP measurement in children. Copyright 2011, SLACK Incorporated.

Quality-Based Backlight Optimization for Video Playback on Handheld Devices

Directory of Open Access Journals (Sweden)

Liang Cheng

2007-01-01

Full Text Available For a typical handheld device, the backlight accounts for a significant percentage of the total energy consumption (e.g., around 30% for a Compaq iPAQ 3650. Substantial energy savings can be achieved by dynamically adapting backlight intensity levels on such low-power portable devices. In this paper, we analyze the characteristics of video streaming services and propose a cross-layer optimization scheme called quality adapted backlight scaling (QABS to achieve backlight energy savings for video playback applications on handheld devices. Specifically, we present a fast algorithm to optimize backlight dimming while keeping the degradation in image quality to a minimum so that the overall service quality is close to a specified threshold. Additionally, we propose two effective techniques to prevent frequent backlight switching, which negatively affects user perception of video. Our initial experimental results indicate that the energy used for backlight is significantly reduced, while the desired quality is satisfied. The proposed algorithms can be realized in real time.

A conceptual application for computer-based procedures for handheld devices

Energy Technology Data Exchange (ETDEWEB)

Sofie, Lunde-Hanssen Linda [Industrial Psychology, Institute for Energy Technology, Halden (Norway)

2014-08-15

This paper describes the concepts and proposed design principles for an application for computer-based procedures (CBPs) for field operators in the nuclear domain (so-called handheld procedures). The concept is focused on the field operators' work with procedures and the communication and coordination between field operators and control room operators. The goal is to overcome challenges with shared situation awareness (SA) in a distributed team by providing effective and usable information design. An iterative design method and user-centred design is used for tailoring the concept to the context of field operations. The resulting concept supports the execution of procedures where close collaboration is needed between control room and field operations, e.g. where particular procedure steps are executed from remote control points and others from the control room. The resulting conceptual application for CBPs on handheld devices is developed for mitigating the SA challenges and designing for usability and ease of use.

A conceptual application for computer-based procedures for handheld devices

International Nuclear Information System (INIS)

Sofie, Lunde-Hanssen Linda

2014-01-01

This paper describes the concepts and proposed design principles for an application for computer-based procedures (CBPs) for field operators in the nuclear domain (so-called handheld procedures). The concept is focused on the field operators' work with procedures and the communication and coordination between field operators and control room operators. The goal is to overcome challenges with shared situation awareness (SA) in a distributed team by providing effective and usable information design. An iterative design method and user-centred design is used for tailoring the concept to the context of field operations. The resulting concept supports the execution of procedures where close collaboration is needed between control room and field operations, e.g. where particular procedure steps are executed from remote control points and others from the control room. The resulting conceptual application for CBPs on handheld devices is developed for mitigating the SA challenges and designing for usability and ease of use

Handheld Nonlinear Detection of Delamination and Intrusion Faults in Composites, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In Phase I of the SBIR program, LEEOAT Company will develop a hand-held high-resolution ultrasonic nonlinear imager for non-destructive inspection (NDI) of...

Combining heterogenous features for 3D hand-held object recognition

Science.gov (United States)

Lv, Xiong; Wang, Shuang; Li, Xiangyang; Jiang, Shuqiang

2014-10-01

Object recognition has wide applications in the area of human-machine interaction and multimedia retrieval. However, due to the problem of visual polysemous and concept polymorphism, it is still a great challenge to obtain reliable recognition result for the 2D images. Recently, with the emergence and easy availability of RGB-D equipment such as Kinect, this challenge could be relieved because the depth channel could bring more information. A very special and important case of object recognition is hand-held object recognition, as hand is a straight and natural way for both human-human interaction and human-machine interaction. In this paper, we study the problem of 3D object recognition by combining heterogenous features with different modalities and extraction techniques. For hand-craft feature, although it reserves the low-level information such as shape and color, it has shown weakness in representing hiconvolutionalgh-level semantic information compared with the automatic learned feature, especially deep feature. Deep feature has shown its great advantages in large scale dataset recognition but is not always robust to rotation or scale variance compared with hand-craft feature. In this paper, we propose a method to combine hand-craft point cloud features and deep learned features in RGB and depth channle. First, hand-held object segmentation is implemented by using depth cues and human skeleton information. Second, we combine the extracted hetegerogenous 3D features in different stages using linear concatenation and multiple kernel learning (MKL). Then a training model is used to recognize 3D handheld objects. Experimental results validate the effectiveness and gerneralization ability of the proposed method.

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

Science.gov (United States)

2013-05-10

...The National Institute of Justice (NIJ) is soliciting interest in supplying hand-held cell phone detector devices for participation in an evaluation by the NIJ Corrections Technology Center of Excellence (CXCoE).

Optical links in handheld multimedia devices

Science.gov (United States)

van Geffen, S.; Duis, J.; Miller, R.

2008-04-01

Ever emerging applications in handheld multimedia devices such as mobile phones, laptop computers, portable video games and digital cameras requiring increased screen resolutions are driving higher aggregate bitrates between host processor and display(s) enabling services such as mobile video conferencing, video on demand and TV broadcasting. Larger displays and smaller phones require complex mechanical 3D hinge configurations striving to combine maximum functionality with compact building volumes. Conventional galvanic interconnections such as Micro-Coax and FPC carrying parallel digital data between host processor and display module may produce Electromagnetic Interference (EMI) and bandwidth limitations caused by small cable size and tight cable bends. To reduce the number of signals through a hinge, the mobile phone industry, organized in the MIPI (Mobile Industry Processor Interface) alliance, is currently defining an electrical interface transmitting serialized digital data at speeds >1Gbps. This interface allows for electrical or optical interconnects. Above 1Gbps optical links may offer a cost effective alternative because of their flexibility, increased bandwidth and immunity to EMI. This paper describes the development of optical links for handheld communication devices. A cable assembly based on a special Plastic Optical Fiber (POF) selected for its mechanical durability is terminated with a small form factor molded lens assembly which interfaces between an 850nm VCSEL transmitter and a receiving device on the printed circuit board of the display module. A statistical approach based on a Lean Design For Six Sigma (LDFSS) roadmap for new product development tries to find an optimum link definition which will be robust and low cost meeting the power consumption requirements appropriate for battery operated systems.

Audiovisual Presentations on a Handheld PC are Preferred As an Educational Tool by NICU Parents.

Science.gov (United States)

Alur, P; Cirelli, J; Goodstein, M; Bell, T; Liss, J

2010-01-01

Health literacy is critical for understanding complex medical problems and necessary for the well being of the patient. Printed educational materials (PM) have limitations in explaining the dynamics of a disease process. Multimedia formats may be useful for enhancing the educational process. To evaluate whether a printed format or animation with commentary on a handheld personal computer (PC) is preferred as an educational tool by parents of a baby in the NICU. PARENTS EVALUATED TWO FORMATS: A 1-page illustrated document from the American Heart Association explaining patent ductus arteriosus (PDA) and animation with commentary on a handheld PC that explained the physiology of PDA in 1 minute. The reading grade level of the PM was 8.6 versus 18.6 for the audio portion of the animated presentation. Parents viewed each format and completed a four-item questionnaire. Parents rated both formats and indicated their preference as printed, animation, or both. Forty-six parents participated in the survey. Parents preferred animation over PM (50% vs. 17.4%. p = 0.02); 39.1% expressed that the animation was excellent; whereas 4.3% expressed that the PM was excellent (p0.05). Parents preferred animation on a small screen handheld PC despite a much higher language level. Because handheld PCs are portable and inexpensive, they can be used effectively at the bedside with low-cost animation to enhance understanding of complex disease conditions.

Epidemiology of Handheld Cell Phone Use While Driving: A Study from a South Indian City

Directory of Open Access Journals (Sweden)

Sumanth Mallikarjuna Majgi

2018-01-01

Full Text Available Background: Using cell phones while driving contribute to distractions which can potentially cause minor or major road traffic injuries and also stress among other drivers. With this background, the study was done to ascertain the proportion of handheld cell phone use while driving among road users in Mysore city and also patterns of the use by the day of week, type of road, and type of vehicle. Methods: The study was conducted in Mysore, Karnataka, India. Four stretches of roads were observed thrice daily for 1 week. The total number of vehicles passing through the stretch and the number and characteristics of drivers using hand-held cell was noted. Pearson's Chi-square test was used to ascertain the significance of the difference in proportions. Results: The overall proportion of cell phone users was calculated as 1.41/100 vehicles. The observed use of handheld cell phones was 1.78 times higher on nonbusy roads than busy roads (Χ2 = 25.79, P < 0.0001. More than 50% of the handheld phone users were driving a two wheeler, the proportion being 50.5% in busy roads, and 67% in nonbusy roads. There was no difference in the proportion of cell phone use by time of the day or across different days of the week. Conclusions: The proportion of drivers who use cell phones is found to be relatively lower, and use of cell phones was higher on nonbusy roads.

Performance Analysis of Nomadic Mobile Services on Multi-homed Handheld Devices

NARCIS (Netherlands)

Pawar, P.; van Beijnum, Bernhard J.F.; van Sinderen, Marten J.; Aggarwal, Akshai; De Clercq, Frederic

2007-01-01

Compared to their predecessors, the current generation handheld mobile devices possess higher processing power, increased memory and new multi-homing capabilities. These features combined with the widespread acceptance and use of these devices result in a situation where mobile devices are no longer

Equine Glaucoma.

Science.gov (United States)

Michau, Tammy Miller

2017-12-01

Glaucoma is a multifactorial neurodegenerative ocular disease leading to progressive loss of retinal ganglion cells and their axons that form the optic nerve, causing blindness. Knowledge of the pathogenesis and development of equine glaucoma is in its infancy compared with human glaucoma. Glaucoma occurs most commonly secondary to uveitis and may be underdiagnosed or misdiagnosed in horses suffering from uveitis. Recognition and clinical diagnosis of glaucoma in the horse is improved with clinician awareness and the availability of handheld tonometers. Therapy for glaucoma is aimed at decreasing aqueous humor production through medical and surgical means. Even with therapy, long-term prognosis for vision is poor. Copyright © 2017 Elsevier Inc. All rights reserved.

How to use hand-held computers to evaluate wood drying.

Science.gov (United States)

Howard N. Rosen; Darrell S. Martin

1985-01-01

Techniques have been developed to evaluate end generate wood drying curves with hand-held computers (3-5K memory). Predictions of time to dry to a specific moisture content, drying rates, and other characteristics of wood drying curves can be made. The paper describes the development of programs and illustrates their use.

ENGAGING SCIENCE STUDENTS WITH HANDHELD TECHNOLOGY AND APPLICATIONS BY RE-VISITING THE THAYER METHOD OF TEACHING AND LEARNING

Directory of Open Access Journals (Sweden)

Julia Paredes

2011-12-01

Full Text Available Organic chemistry instructors integrate handheld technology and applications into course lecture and lab to engage students with tools and techniques students use in the modern world. This technology and applications enable instructors to re-visit the Thayer Method of teaching and learning to create an updated method that works with 21st century students. The Thayer Method is based on the premise that students are willing and capable of making substantial preparation before coming to class and lab in order to maximize efficiency of student-instructor contact time. During this student preparation phase, we engage students with handheld technology and content applications including smart phone viewable course administrative materials; “flashcards” containing basic organic chemistry nomenclature, molecular structures, and chemical reactions; mini-lectures prepared using the Smart Board Airliner Interactive Tablet for upcoming class periods and laboratory technique videos demonstrating tasks they will perform as part of laboratory experimentation. Coupled with a student friendly course text, these handheld applications enable substantial student preparation before class and lab. The method, in conjunction with handheld technology and applications, has been used with positive results in our organic chemistry courses.

A comparison between Goldmann applanation tonometry and dynamic contour tonometry after photorefractive keratectomy.

Science.gov (United States)

Sadigh, Afshin Lotfi; Fouladi, Rohollah F; Hashemi, Hassan; Beheshtnejad, Amir Houshang

2013-02-01

The intraocular pressure (IOP) could be measured by both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT). Although these two methods have been discussed widely after laser-assisted sub-epithelial keratectomy (LASIK), there is little data in the cases undergoing photorefractive keratectomy (PRK). We aimed to compare the changes of IOP measurements obtained by GAT and DCT after PRK for myopia/myopic astigmatism. This prospective study enrolled 77 candidates (154 eyes) for PRK to correct myopia or myopic astigmatism and 30 matched patients (30 eyes) with myopia or myopic astigmatism who served as controls. Changes of the IOP measurements (ΔIOP) obtained by GAT and DCT before and at 6 months after PRK in the operated eyes, and at baseline and 6 months later in the controls, were documented. Changes of the central corneal thickness (ΔCCT) were determined in the same fashion. The mean IOP readings obtained by DCT were comparable before and at 6 months after procedure (18.34 ± 3.03 mmHg and 17.87 ± 2.61 mmHg respectively, p = 0.41); whereas the mean IOP reading obtained by GAT decreased significantly 6 months postoperatively (17.92 ± 3.63 mmHg and 16.25 ± 2.66 mmHg, p vs 0.07 ± 0.44 mmHg, p = 0.02). The mean DCT-obtained ΔIOP was just marginally insignificant between the operated and nonoperated eyes (-0.63 ± 0.59 vs 0.02 ± 0.38 mmHg respectively; p = 0.09). The authors recommend DCT after PRK in the cases with myopia or myopic astigmatism.

The Weak Link HP-41C hand-held calculator program

Science.gov (United States)

Ross A. Phillips; Penn A. Peters; Gary D. Falk

1982-01-01

The Weak Link hand-held calculator program (HP-41C) quickly analyzes a system for logging production and costs. The production equations model conventional chain saw, skidder, loader, and tandemaxle truck operations in eastern mountain areas. Production of each function of the logging system may be determined so that the system may be balanced for minimum cost. The...

Computational study to investigate effect of tonometer geometry and patient-specific variability on radial artery tonometry.

Science.gov (United States)

Singh, Pranjal; Choudhury, Mohammed Ikbal; Roy, Sitikantha; Prasad, Anamika

2017-06-14

Tonometry-based devices are valuable method for vascular function assessment and for measurement of blood pressure. However current design and calibration methods rely on simple models, neglecting key geometrical features, and anthropometric and property variability among patients. Understanding impact of these influences on tonometer measurement is thus essential for improving outcomes of current devices, and for proposing improved design. Towards this goal, we present a realistic computational model for tissue-device interaction using complete wrist section with hyperelastic material and frictional contact. Three different tonometry geometries were considered including a new design, and patient-specific influences incorporated via anthropometric and age-dependent tissue stiffness variations. The results indicated that the new design showed stable surface contact stress with minimum influence of the parameters analyzed. The computational predictions were validated with experimental data from a prototype based on the new design. Finally, we showed that the underlying mechanics of vascular unloading in tonometry to be fundamentally different from that of oscillatory method. Due to directional loading in tonometry, pulse amplitude maxima was observed to occur at a significantly lower compression level (around 31%) than previously reported, which can impact blood pressure calibration approaches based on maximum pulse pressure recordings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Standardization from a benchtop to a handheld NIR spectrometer using mathematically mixed NIR spectra to determine fuel quality parameters

DEFF Research Database (Denmark)

da Silva, Neirivaldo Cavalcante; Cavalcanti, Claudia Jessica; Honorato, Fernanda Araujo

2017-01-01

spectral responses of fuel samples (gasoline and biodiesel blends) from a high-resolution benchtop Frontier FT-NIR (PerkinElmer) spectrometer and a handheld MicroNIR™1700 (JDSU). These virtual standards can be created by mathematically mixing spectra from the pure solvents present in gasoline or diesel...... to the handheld MicroNIR using virtual standards as transfer samples...

The impact of intraocular pressure reduction on retrobulbar hemodynamic parameters in patients with open-angle glaucoma.

Science.gov (United States)

Marjanovic, Ivan; Milic, Natasa; Martinez, Antonio

2012-01-01

To assess the retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCA) after decreasing elevated intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) by using color Doppler imaging. A total of 46 eyes from 46 patients with OAG, with elevated IOP, were consecutively included in this prospective study. Peak-systolic velocity, end-diastolic velocity, and Pourcelot resistivity index were assessed in the OA, CRA, and PCA. The IOP was measured with Goldmann applanation tonometer (GAT) and the dynamic contour tonometer (DCT), 3 times respectively. Ocular pulse amplitude (OPA) appeared during the DCT measurement. After decreasing the elevated IOP, measured with both GAT and DCT, the retrobulbar parameters showed no differences as compared with baseline measurements. After Bonferroni correction (p ≤ 0.0042, alpha/12), statistical significance appeared in retrobulbar hemodynamics only in DCT (29.3 ± 6.4 vs 15.5 ± 4.2 mmHg), GAT (33.0 ± 8.3 vs 15.8 ± 7.0 mmHg), and OPA measurements (4.1 ± 1.3 vs 2.7 ± 1.4 mmHg), in comparison to baseline. There was no correlation between the changes in IOP measured with either DCT or GAT and the changes in the retrobulbar hemodynamic parameters (p>0.05 for all). The results of our study suggested a lack of correlation between the changes in IOP, measured with either DCT or GAT, and the changes in the retrobulbar hemodynamic parameters. The results of our study might suggest that the blood flow disturbances found in glaucoma patients are independent of the IOP.

Detection of subclinical keratoconus through non-contact tonometry and the use of discriminant biomechanical functions.

Science.gov (United States)

Peña-García, Pablo; Peris-Martínez, Cristina; Abbouda, Alessandro; Ruiz-Moreno, José M

2016-02-08

The purpose of the present study was to develop a discriminant function departing from the biomechanical parameters provided by a non-contact tonometer (Corvis-ST, Oculus Optikgeräte, Wetzlar, Germany) to distinguish subclinical keratoconus from normal eyes. 212 eyes (120 patients) were divided in two groups: 184 healthy eyes of 92 patients aged 32.99 ± 7.85 (21-73 years) and 28 eyes of 28 patients aged 37.79 ± 14.21 (17-75 years) with subclinical keratoconus. The main outcome measures were age, sex, intraocular pressure (IOP), corneal central thickness (CCT) and other specific biomechanical parameters provided by the tonometer. Correlations between all biomechanical parameters and the rest of variables were evaluated. The biomechanical measures were corrected in IOP and CCT (since these variable are not directly related with the corneal structure and biomechanical behavior) to warrant an accurate comparison between both types of eyes. Two discriminant functions were created from the set of corrected variables. The best discriminant function created depended on three parameters: maximum Deformation Amplitude (corrected in IOP and CCT), First Applanation time (corrected in CCT) and CCT. Statistically significant differences were found between groups for this function (p=2·10(-10); Mann-Withney test). The area under the Receiving Operating Characteristic was 0.893 ± 0.028 (95% confidence interval 0.838-0.949). Sensitivity and specificity were 85.7% and 82.07% respectively. These results show that the use of biomechanical parameters provided by non-contact tonometry, previous normalization, combined with the theory of discriminant functions is a useful tool for the detection of subclinical keratoconus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of dual sensor hand-held detector

Science.gov (United States)

Sezgin, Mehmet

2010-04-01

In this paper hand-held dual sensor detector development requirements are considered dedicated to buried object detection. Design characteristics of such a system are categorized and listed. Hardware and software structures, ergonomics, user interface, environmental and EMC/EMI tests to be applied and performance test issues are studied. Main properties of the developed system (SEZER) are presented, which contains Metal Detector (MD) and Ground Penetrating Radar (GPR). The realized system has ergonomic structure and can detect both metallic and non-metallic buried objects. Moreover classification of target is possible if it was defined to the signal processing software in learning phase.

Reusable Handheld Electrolytes and Lab Technology for Humans (rHEALTH Sensor), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The goal of rHEALTH sensor is a universal handheld sensor that can provide rapid, low-cost complete blood count (CBC) with differential, electrolyte analysis, and...

Reusable Handheld Electrolytes and Lab Technology for Humans (rHEALTH Sensor), Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The goal of the rHEALTH sensor is to provide rapid, low-cost, handheld complete blood count (CBC), cell differential counts, electrolyte measurements, and other lab...

A RARE CASE OF BILATERAL MICROSPHEREPHAKIA

Directory of Open Access Journals (Sweden)

Pandu

2015-05-01

Full Text Available Microspherophakia is rare bilateral congenital anamoly of the crystalline lens. The condition may be isolated , familial or it may be associated with systemic affections like Marfan's syndrome , Weil - Marchesani syndrome , hyperlysinemia and congenital rubella. Microspherophakia results in lenticular myopia , lens dislocation , usually inferiorly and inverse glaucoma. We present a case in a 8 year old child who presented with bilateral microspherophakia and anterior dislocation of lens of right eye. visual acuity in right eye was counting fingers close to face and i n left eye 6/60.IOP with perkins applanation tonometer was 30mmHg in right eye 22mmHg in left eye , cornea was hazy due to edema , anterior chamber was shallow in both eye patient was managed with emergency lens extraction of right eye and secondary ACIOL im plantation. Left eye was managed by laser peripheral iridotomy. IOP was within normal limits postoperatively in both eyes without any antiglaucoma medications. Postoperatively best corrected visual acuity in right was 6/18 and 6/9 in left eye.

An evaluation of the effects of eyeball structure on ocular pulse amplitude in healthy subjects.

Science.gov (United States)

Ishii, Kotaro; Mori, Mikiro; Oshika, Tetsuro

2012-12-01

To evaluate the effects of eyeball structure on ocular pulse amplitude (OPA) measured using dynamic contour tonometer (DCT). In 86 eyes of 43 healthy subjects, we measured OPA and intraocular pressure (IOP) with DCT (DCT-IOP), IOP with Goldmann applanation tonometry (GAT-IOP), central corneal thickness (CCT), corneal thickness 2 mm (2 mmCT) and 4 mm (4 mmCT) apart from the center, corneal volume within a 3.5-mm radius from the corneal center, corneal curvature, anterior chamber depth, anterior chamber volume, and axial length (AL). OPA had a significant positive correlation with GAT-IOP (Pearson's r = 0.412, p < 0.001), DCT-IOP (r = 0.350, p < 0.001), and 4 mmCT (r = 0.244, p = 0.0231), and had a significant negative correlation with AL (r = -0.268, p = 0.0122). In a multiple linear regression analysis, AL and GAT-IOP were significantly associated with OPA. OPA measured with DCT is significantly influenced by several factors, such as IOP, peripheral corneal thickness (4 mmCT), and AL.

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

Science.gov (United States)

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.

Comparison of ICare and IOPen vs Goldmann applanation tonometry according to international standards 8612 in glaucoma patients.

Science.gov (United States)

Pahlitzsch, Milena; Brünner, Jeanette; Gonnermann, Johannes; Maier, Anna-Karina B; Torun, Necip; Bertelmann, Eckart; Klamann, Matthias Kj

2016-01-01

To compare IOPen and ICare rebound tonometry to Goldmann applanation tonometry (GAT) according to International Standards Organization (ISO) 8612 criteria. Totally 191 eyes ( n =107 individuals) were included. Criteria of ISO 8612 were fulfilled: 3 clusters of IOP, measured by GAT, were formed. The GAT results were given as mean±standard deviation. GAT (19.7±0.5 mm Hg) showed a significant correlation to ICare (19.8±0.5 mm Hg) ( r =0.547, P 0.5 mm Hg) ( r =0.526, P <0.001). According to ISO 8612 criteria in all 3 IOP groups the number of outliers (of the 95% limits of agreement) exceeded 5% for ICare and IOPen vs GAT: No.1 ( n =68) 29.4% and 22.1%, No.2 ( n =62) 35.5% and 37.1%, No.3 ( n =61) 26.2% and 42.6%, respectively. The strict requirements of the ISO 8612 are not fulfilled in a glaucoma collective by ICare and IOPen at present. As long as the Goldmann tonometry is applicable it should be used first of all for reproducible IOP readings. ICare and IOPen tonometry should be considered as an alternative tool, if application of Goldmann tonometry is not possible.

[New trends in tonometry].

Science.gov (United States)

Draeger, J A; Schwenteck, T; Ruokonen, P C

2006-10-01

Though the knowledge about the risk of elevated intraocular pressure for pathogenesis for development and progress of glaucoma is more than 400 years old. It took another 300 years before by means of tonometry this elevation could be quantified. After discussion of the key words it is our aim to demonstrate the latest trends in tonometry, specifically by use of modern electronics for instrument design. Goldmann was the founder of the "applanation tonometry", measuring the corelation of applanated area and applied force. Here, the next step was the development of instruments, measuring independent of position or gravity to allow application also at the lying patient. Electronic area detection was the next step to avoid examinor's error. Also important was the introduction of automatic UV-desinfection to avoid contamination of the other eye or other patients. Other tonometers control the force applied by an inductive method, which also allows application independent of position. Airpuff-tonometry uses completely different measuring principles - the resulting change of corneal curvature indicates the intraocular pressure. The impedance principle is applied even through the closed eye lid. The shock waves resulting shall be measured. Direct application of a surface sensor incorporated into a concave surface contact body shall allow direct measurement of intraocular pressure independent of corneal thickness, curvature, astigmatism. This method has been tried for more than 20 years. Also exposition of the eye to count waves of different frequency was an early attempt. Here also change of reflectivity is used to calculate intraocular pressure. Even after use of modern electronic technology the precision of many of these new devices does not lead to better results. This specifically is shown by modern calibration methods.

Gen-2 Hand-Held Optical Imager towards Cancer Imaging: Reflectance and Transillumination Phantom Studies

Directory of Open Access Journals (Sweden)

Anuradha Godavarty

2012-02-01

Full Text Available 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.

The reliability and validity of hand-held refractometry water content measures of hydrogel lenses.

Science.gov (United States)

Nichols, Jason J; Mitchell, G Lynn; Good, Gregory W

2003-06-01

To investigate within- and between-examiner reliability and validity of hand-held refractometry water content measures of hydrogel lenses. Nineteen lenses of various nominal water contents were examined by two examiners on two occasions separated by 1 hour. An Atago N2 hand-held refractometer was used for all water content measures. Lenses were presented in a random order to each examiner by a third party, and examiners were masked to any potential lens identifiers. Intraclass correlation coefficients (ICC), 95% limits of agreement, and Wilcoxon signed rank test were used to characterize the within- and between-examiner reliability and validity of lens water content measures. Within-examiner reliability was excellent (ICC, 0.97; 95% limits of agreement, -3.6% to +5.7%), and the inter-visit mean difference of 1.1 +/- 2.4% was not biased (p = 0.08). Between-examiner reliability was also excellent (ICC, 0.98; 95% limits of agreement, -4.1% to +3.9%). The mean difference between examiners was -0.1 +/- 2.1% (p = 0.83). The mean difference between the nominally reported water content and our water content measures was -2.1 +/- 1.7% (p refractometry and is material dependent. Therefore, investigators may need to account for bias when measuring hydrogel lens water content via hand-held refractometry.

Hand-held transendoscopic robotic manipulators: A transurethral laser prostate surgery case study.

Science.gov (United States)

Hendrick, Richard J; Mitchell, Christopher R; Herrell, S Duke; Webster, Robert J

2015-11-01

Natural orifice endoscopic surgery can enable incisionless approaches, but a major challenge is the lack of small and dexterous instrumentation. Surgical robots have the potential to meet this need yet often disrupt the clinical workflow. Hand-held robots that combine thin manipulators and endoscopes have the potential to address this by integrating seamlessly into the clinical workflow and enhancing dexterity. As a case study illustrating the potential of this approach, we describe a hand-held robotic system that passes two concentric tube manipulators through a 5 mm port in a rigid endoscope for transurethral laser prostate surgery. This system is intended to catalyze the use of a clinically superior, yet rarely attempted, procedure for benign prostatic hyperplasia. This paper describes system design and experiments to evaluate the surgeon's functional workspace and accuracy using the robot. Phantom and cadaver experiments demonstrate successful completion of the target procedure via prostate lobe resection.

Maintaining radiation exposures as low as reasonably achievable (ALARA) for dental personnel operating portable hand-held x-ray equipment.

Science.gov (United States)

McGiff, Thomas J; Danforth, Robert A; Herschaft, Edward E

2012-08-01

Clinical experience indicates that newly available portable hand-held x-ray units provide advantages compared to traditional fixed properly installed and operated x-ray units in dental radiography. However, concern that hand-held x-ray units produce higher operator doses than fixed x-ray units has caused regulatory agencies to mandate requirements for use of hand-held units that go beyond those recommended by the manufacturer and can discourage the use of this technology. To assess the need for additional requirements, a hand-held x-ray unit and a pair of manikins were used to measure the dose to a simulated operator under two conditions: exposures made according to the manufacturer's recommendations and exposures made according to manufacturer's recommendation except for the removal of the x-ray unit's protective backscatter shield. Dose to the simulated operator was determined using an array of personal dosimeters and a pair of pressurized ion chambers. The results indicate that the dose to an operator of this equipment will be less than 0.6 mSv y⁻¹ if the device is used according to the manufacturer's recommendations. This suggests that doses to properly trained operators of well-designed, hand-held dental x-ray units will be below 1.0 mSv y⁻¹ (2% of the annual occupational dose limit) even if additional no additional operational requirements are established by regulatory agencies. This level of annual dose is similar to those reported as typical dental personnel using fixed x-ray units and appears to satisfy the ALARA principal for this class of occupational exposures.

Application of Suresight handheld auto-refractometer in refraction screening for infants in Community Health Service Center

Directory of Open Access Journals (Sweden)

Li-Hua Guo

2014-08-01

Full Text Available AIM: To observe the application of Suresight handheld auto-refractometer in measuring diopter of infants in Community Health Service Center. METHODS:Totally 836 cases(1 672 eyesfrom June 2013 to December 2013 were examined diopter of infants by Suresight handheld auto-refractometer in Community Health Service Center. RESULTS: Within 1 672 eyes of 836 infants were examined, 202 eyes were diagnosed ametropia, 38 eyes were suspicious, 240 eyes were transferred to the department of ophthalmology, the referral rate was 14.35%; 172 eyes were diagnosed ametropia, and the diagnosis rate of the referral patients was 71.67%. Among 172 eyes, 46 eyes were provided with corrected glasses, accounting for 2.75% of the number of screening, and 126 eyes were given intensive monitoring, accounting for 7.54% of the number of screening.CONCLUSION: Application of Suresight handheld auto-refractometer in refraction screening for infants in Community Health Service Center is convenient and effective. With two-way referral between community health service center and department of ophthalmology can monitor and intervene vision development of infants much earlier.

Classification and Visualization of Physical and Chemical Properties of Falsified Medicines with Handheld Raman Spectroscopy and X-Ray Computed Tomography.

Science.gov (United States)

Kakio, Tomoko; Yoshida, Naoko; Macha, Susan; Moriguchi, Kazunobu; Hiroshima, Takashi; Ikeda, Yukihiro; Tsuboi, Hirohito; Kimura, Kazuko

2017-09-01

Analytical methods for the detection of substandard and falsified medical products (SFs) are important for public health and patient safety. Research to understand how the physical and chemical properties of SFs can be most effectively applied to distinguish the SFs from authentic products has not yet been investigated enough. Here, we investigated the usefulness of two analytical methods, handheld Raman spectroscopy (handheld Raman) and X-ray computed tomography (X-ray CT), for detecting SFs among oral solid antihypertensive pharmaceutical products containing candesartan cilexetil as an active pharmaceutical ingredient (API). X-ray CT visualized at least two different types of falsified tablets, one containing many cracks and voids and the other containing aggregates with high electron density, such as from the presence of the heavy elements. Generic products that purported to contain equivalent amounts of API to the authentic products were discriminated from the authentic products by the handheld Raman and the different physical structure on X-ray CT. Approach to investigate both the chemical and physical properties with handheld Raman and X-ray CT, respectively, promise the accurate discrimination of the SFs, even if their visual appearance is similar with authentic products. We present a decision tree for investigating the authenticity of samples purporting to be authentic commercial tablets. Our results indicate that the combination approach of visual observation, handheld Raman and X-ray CT is a powerful strategy for nondestructive discrimination of suspect samples.

Adaptive RF front-ends for hand-held applications

CERN Document Server

van Bezooijen, Andre; van Roermund, Arthur

2010-01-01

The RF front-end - antenna combination is a vital part of a mobile phone because its performance is very relevant to the link quality between hand-set and cellular network base-stations. The RF front-end performance suffers from changes in operating environment, like hand-effects, that are often unpredictable. ""Adaptive RF Front-Ends for Hand-Held Applications"" presents an analysis on the impact of fluctuating environmental parameters. In order to overcome undesired behavior two different adaptive control methods are treated that make RF frond-ends more resilient: adaptive impedance control,

Handheld Longwave Infrared Camera Based on Highly-Sensitive Quantum Well Infrared Photodetectors, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop a compact handheld longwave infrared camera based on quantum well infrared photodetector (QWIP) focal plane array (FPA) technology. Based on...

A data-driven design evaluation tool for handheld device soft keyboards.

Directory of Open Access Journals (Sweden)

Matthieu B Trudeau

Full Text Available 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.

Comparative Geometrical Accuracy Investigations of Hand-Held 3d Scanning Systems - AN Update

Science.gov (United States)

Kersten, T. P.; Lindstaedt, M.; Starosta, D.

2018-05-01

Hand-held 3D scanning systems are increasingly available on the market from several system manufacturers. These systems are deployed for 3D recording of objects with different size in diverse applications, such as industrial reverse engineering, and documentation of museum exhibits etc. Typical measurement distances range from 0.5 m to 4.5 m. Although they are often easy-to-use, the geometric performance of these systems, especially the precision and accuracy, are not well known to many users. First geometrical investigations of a variety of diverse hand-held 3D scanning systems were already carried out by the Photogrammetry & Laser Scanning Lab of the HafenCity University Hamburg (HCU Hamburg) in cooperation with two other universities in 2016. To obtain more information about the accuracy behaviour of the latest generation of hand-held 3D scanning systems, HCU Hamburg conducted further comparative geometrical investigations using structured light systems with speckle pattern (Artec Spider, Mantis Vision PocketScan 3D, Mantis Vision F5-SR, Mantis Vision F5-B, and Mantis Vision F6), and photogrammetric systems (Creaform HandySCAN 700 and Shining FreeScan X7). In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data was acquired by measurements with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M). The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

A Fresh Look at the Crystal Violet Lab with Handheld Camera Colorimetry

Science.gov (United States)

Knutson, Theodore R.; Knutson, Cassandra M.; Mozzetti, Abbie R.; Campos, Antonio R.; Haynes, Christy L.; Penn, R. Lee

2015-01-01

Chemical kinetic experiments to determine rate laws are common in high school and college chemistry courses. For reactions involving a color change, rate laws can be determined experimentally using spectrophotometric or colorimetric equipment though this equipment can be cost prohibitive. Previous work demonstrated that inexpensive handheld camera…

Torque Removal Evaluation of Screw in One-Piece and Two-Piece Abutments Tightened with a Handheld screwdriver

Directory of Open Access Journals (Sweden)

Jalil Ghanbarzadeh

2013-12-01

Full Text Available Introduction: Some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. The aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. Methods: 40 ITI implants were placed in acrylic blocks and divided into 4 groups. In groups one and two, 10 ITI one-piece abutments (Solid® and in groups three and four, 10 ITI two-piece abutments (Synocta® were placed on the implants. In groups one and three abutments were tightened by 5 experienced males and 5 experienced females using a handheld driver. In groups two and four abutments were tightened using a torque wrench with torque values of 10, 20 and 35 N.cm. Insertion torque and removal torque values of the abutments were measured with a digital torque meter. Results: The insertion torque values (ITVs of males in both abutments were significantly higher than those of females. ITVs in both Solid® and Synocta® abutments tightened with a handheld screwdriver were similar to the torque of 20 N.cm in the torque wrench. Removal torque values (RTVs of solid® abutments were higher than those of synocta® abutments. Conclusion: The one- piece abutments (solid® showed higher RTVs than the two-piece abutments (synocta®. Hand driver does not produce sufficient preload force for the final tightening of the abutment

Handheld Delivery System for Modified Boron-Type Fire Extinguishment Agent

Science.gov (United States)

1993-11-01

was to develop and test a handheld portable delivery system for use with the modified boron-type fire extinguishing agent for metal fires . B...BACKGROUND A need exists for an extinguishing agent and accompanying delivery system that are effective against complex geometry metal fires . A modified...agent and its delivery system have proven effective against complex geometry metal fires containing up to 200 pounds of magnesium metal. Further

Handheld microwave bomb-detecting imaging system

Science.gov (United States)

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 Versus Wearable Interaction Design for Professionals - A Case Study of Hospital Service Work

DEFF Research Database (Denmark)

Stisen, Allan; Blunck, Henrik; Kjærgaard, Mikkel Baun

2014-01-01

With the blooming of new available wrist worn devices there are potentials for these to support the work done in many professional domains. One such domain is hospital service work. This paper explores two wearable prototypes with regards to challenges and opportunities to support future hospital...... service work. This explorative study was conducted with 4 experienced hospital orderlies who interacted with an application across two wearable concepts, and one handheld smartphone in five scenarios in a hospital environment. The interaction was video recorded with a chest-mounted video afterwards semi...... structured interviews with each participant was conducted. This study shows that wearable computers can effectively support the maintenance work of the orderlies and has domain specific advantages over the handheld smartphone, e.g., the former support glancing at the task information. Furthermore, we outline...

Handheld pose tracking using vision-inertial sensors with occlusion handling

Science.gov (United States)

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.

Goldmann applanation tonometry compared with corneal-compensated intraocular pressure in the evaluation of primary open-angle Glaucoma

Directory of Open Access Journals (Sweden)

Ehrlich Joshua R

2012-09-01

Full Text Available Abstract Background To better understand the role of corneal properties and intraocular pressure (IOP in the evaluation of primary open-angle glaucoma (POAG; and to determine the feasibility of identifying glaucomatous optic neuropathy (GON using IOP corrected and uncorrected for corneal biomechanics. Methods Records from 1,875 eyes of consecutively evaluated new patients were reviewed. Eyes were excluded if central corneal thickness (CCT or Ocular Response Analyzer (ORA measurements were unavailable. Presence or absence of GON was determined based on morphology of the optic disc, rim and retinal nerve fiber layer at the time of clinical examination, fundus photography and Heidelberg Retinal Tomography. Goldmann-applanation tonometry (GAT in the untreated state was recorded and Goldmann-correlated (IOPg and corneal-compensated IOP (IOPcc were obtained using the ORA. Glaucomatous eyes were classified as normal or high-tension (NTG, HTG using the conventional cutoff of 21 mm Hg. One eligible eye was randomly selected from each patient for inclusion. Results A total of 357 normal, 155 HTG and 102 NTG eyes were included. Among NTG eyes, IOPcc was greater than GAT (19.8 and 14.4 mm Hg; p  Conclusions IOPcc may account for measurement error induced by corneal biomechanics. Compared to GAT, IOPcc may be a superior test in the evaluation of glaucoma but is unlikely to represent an effective diagnostic test.

Radiation safety evaluation of a hand-held, battery operated image intensifier

International Nuclear Information System (INIS)

Wilson, O.J.; Young, B.F.

1987-01-01

A portable, hand-held, fluoroscopic unit intended for medical and industrial use was tested to verify the claim of the manufacturers that the radiation doses to the patient and user are low, and comparable to those received from standard radiographic procedures. The first claim was substantiated but not the second. A number of concerns arising from the use of this unit are discussed

A BODIPY-Based Fluorescent Probe to Visually Detect Phosgene: Toward the Development of a Handheld Phosgene Detector.

Science.gov (United States)

Sayar, Melike; Karakuş, Erman; Güner, Tuğrul; Yildiz, Busra; Yildiz, Umit Hakan; Emrullahoğlu, Mustafa

2018-03-02

A boron-dipyrromethene (BODIPY)-based fluorescent probe with a phosgene-specific reactive motif shows remarkable selectivity toward phosgene, in the presence of which the nonfluorescent dye rapidly transforms into a new structure and induces a fluorescent response clearly observable to the naked eye under ultraviolet light. Given that dynamic, a prototypical handheld phosgene detector with a promising sensing capability that expedites the detection of gaseous phosgene without sophisticated instrumentation was developed. The proposed method using the handheld detector involves a rapid response period suitable for issuing early warnings during emergency situations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficacy of Handheld Electronic Visual Supports to Enhance Vocabulary in Children with ASD

Science.gov (United States)

Ganz, Jennifer B.; Boles, Margot B.; Goodwyn, Fara D.; Flores, Margaret M.

2014-01-01

Although electronic tools such as handheld computers have become increasingly common throughout society, implementation of such tools to improve skills in individuals with intellectual and developmental disabilities has lagged in the professional literature. However, the use of visual scripts for individuals with disabilities, particularly those…

A study of cladding technology on tube wall surface by a hand-held laser torch

International Nuclear Information System (INIS)

Terada, Takaya; Nishimura, Akihiko; Oka, Kiyoshi; Moriyama, Taku; Matsuda, Hiroyasu

2015-01-01

New maintenance technique was proposed using a hand-held laser torch for aging chemical plants and power plants. The hand-held laser torch was specially designed to be able to access limited tubular space in various cases. A composite-type optical fiberscope was composed of a center fiber for beam delivery and surrounded fibers for visible image delivery. Laser irradiation on a work pieces with the best accuracy of filler wire was carried out. And, we found that the optimized wire-feed speed was 2 mm/s in laser cladding. We succeeded to make a line clad on the inner wall of 23 mm tube. This technique was discussed to be applied to the maintenance for cracks or corrosions of tubes in various harsh environments. (author)

Evolving Consumption Patterns of Various Information Media via Handheld Mobile Devices

Directory of Open Access Journals (Sweden)

Nitza Geri

2015-06-01

Full Text Available This study examines diverse information media in order to identify those formats that are most suitable for consumption via handheld mobile devices, namely, smartphones and tablets. The preferences of the users are measured objectively by analyzing actual data of their relative use of handheld mobile devices and personal computing (PC desktop devices, including laptops and notebooks, for consumption of information presented in various formats. Our findings are based on Google Analytics pageview data of five course Websites during a period of three semesters, by 11,557 undergraduate students. M-learning contexts were chosen, since in a learning environment the interests of information providers (i.e., the instructors are in accord with those of the information consumers (i.e., the students, whereas in commercial settings there may be conflicts of interests. Our findings demonstrate that although about 90% of the pageviews were via PC devices, the rate of smartphone use for consuming learning content in diverse information media is gradually increasing as time goes by, whereas the rate of tablet use for these purposes is stagnant. The most promising direction for smartphone development, emanating from the findings, is online video content.

Hand-held indirect calorimeter offers advantages compared with prediction equations, in a group of overweight women, to determine resting energy expenditures and estimated total energy expenditures during research screening.

Science.gov (United States)

Spears, Karen E; Kim, Hyunsook; Behall, Kay M; Conway, Joan M

2009-05-01

To compare standardized prediction equations to a hand-held indirect calorimeter in estimating resting energy and total energy requirements in overweight women. Resting energy expenditure (REE) was measured by hand-held indirect calorimeter and calculated by prediction equations Harris-Benedict, Mifflin-St Jeor, World Health Organization/Food and Agriculture Organization/United Nations University (WHO), and Dietary Reference Intakes (DRI). Physical activity level, assessed by questionnaire, was used to estimate total energy expenditure (TEE). Subjects (n=39) were female nonsmokers older than 25 years of age with body mass index more than 25. Repeated measures analysis of variance, Bland-Altman plot, and fitted regression line of difference. A difference within +/-10% of two methods indicated agreement. Significant proportional bias was present between hand-held indirect calorimeter and prediction equations for REE and TEE (Pvalues and underestimated at higher values. Mean differences (+/-standard error) for REE and TEE between hand-held indirect calorimeter and Harris-Benedict were -5.98+/-46.7 kcal/day (P=0.90) and 21.40+/-75.7 kcal/day (P=0.78); between hand-held indirect calorimeter and Mifflin-St Jeor were 69.93+/-46.7 kcal/day (P=0.14) and 116.44+/-75.9 kcal/day (P=0.13); between hand-held indirect calorimeter and WHO were -22.03+/-48.4 kcal/day (P=0.65) and -15.8+/-77.9 kcal/day (P=0.84); and between hand-held indirect calorimeter and DRI were 39.65+/-47.4 kcal/day (P=0.41) and 56.36+/-85.5 kcal/day (P=0.51). Less than 50% of predictive equation values were within +/-10% of hand-held indirect calorimeter values, indicating poor agreement. A significant discrepancy between predicted and measured energy expenditure was observed. Further evaluation of hand-held indirect calorimeter research screening is needed.

Intraocular pressure values obtained by ocular response analyzer, dynamic contour tonometry, and goldmann tonometry in keratokonic corneas.

Science.gov (United States)

Bayer, Atilla; Sahin, Afsun; Hürmeriç, Volkan; Ozge, Gökhan

2010-01-01

To determine the agreement between dynamic contour tonometer (DCT), Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA) in keratoconic corneas and to find out the effect of corneal biomechanics on intraocular pressure (IOP) measurements obtained by these devices. IOP was measured with the ORA, DCT, and GAT in random order in 120 eyes of 61 keratoconus patients. Central corneal thickness (CCT) and keratometry were measured after all IOP determinations had been made. The mean IOP measurement by the ORA and DCT was compared with the measurement by the GAT, using Student t test. Bland-Altman analysis was performed to assess the clinical agreement between these methods. The effect of corneal hysteresis (CH), corneal resistance factor (CRF), and CCT on measured IOP was explored by multiple backward stepwise linear regression analysis. The mean±SD patient age was 30.6±11.2 years. The mean±SD IOP measurement obtained with GAT, ORA Goldmann-correlated IOP (IOPg), ORA corneal-compensated IOP (IOPcc), and DCT was 10.96±2.8, 10.23±3.5, 14.65±2.8, and 15.42±2.7 mm Hg, respectively. The mean±SD CCT was 464.08±58.4 microns. The mean difference between IOPcc and GAT (P<0.0001), IOPcc and DCT (P<0.001), GAT and DCT (P<0.0001), IOPg and GAT (P<0.002), and IOPg and DCT (P<0.0001), was highly statistically significant. In multivariable regression analysis, DCT IOP and GAT IOP measurements were significantly associated with CH and CRF (P<0.0001 for both). DCT seemed to be affected by CH and CRF, and the IOP values tended to be higher when compared with GAT. ORA-measured IOPcc was found to be independent of CCT and suitable in comparison to the DCT in keratoconic eyes.

Handheld Multi-Gas Meters Assessment Report

Energy Technology Data Exchange (ETDEWEB)

Williams, Gustavious [Brigham Young Univ., Provo, UT (United States); Wald-Hopkins, Mark David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Obrey, Stephen J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Akhadov, Valida Dushdurova [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-06-27

Handheld multi-gas meters (MGMs) are equipped with sensors to monitor oxygen (O2) levels and additional sensors to detect the presence of combustible or toxic gases in the environment. This report is limited to operational response-type MGMs that include at least four different sensors. These sensors can vary by type and by the monitored chemical. In real time, the sensors report the concentration of monitored gases in the atmosphere near the MGM. In April 2016 the System Assessment and Validation for Emergency Responders (SAVER) Program conducted an operationally-oriented assessment of MGMs. Five MGMs were assessed by emergency responders. The criteria and scenarios used in this assessment were derived from the results of a focus group of emergency responders with experience in using MGMs. The assessment addressed 16 evaluation criteria in four SAVER categories: Usability, Capability, Maintainability, and Deployability.

Biomechanical responses of healthy and keratoconic corneas measured using a noncontact scheimpflug-based tonometer.

Science.gov (United States)

Ali, Noor Q; Patel, Dipika V; McGhee, Charles N J

2014-05-15

To examine the repeatability of measurements obtained using a noncontact Scheimpflug-based tonometer (Corvis ST) and investigate potential differences in these parameters between healthy and keratoconic (KC) corneas. Forty-five keratoconic eyes and 103 healthy eyes were examined using biomicroscopy, corneal tomography and the Corvis ST (CST). Intraocular pressure and central corneal thickness (CCT) were highly repeatable (intraclass correlation [ICC] > 0.70, coefficient of variation [CV] 0.60, CV < 0.20). There was no association between DA and age, sex, or ethnicity in healthy eyes. There was a greater mean DA in the KC group compared with 46 age-matched healthy eyes (KC 1.37 ± 0.21 mm, healthy 1.05 ± 0.11 mm, P < 0.001). Multivariate analysis showed DA in KC was predicted by IOP, CCT, and the steepest simulated keratometry value (P = 0.03, P = 0.03, P = 0.001 respectively, R(2) = 0.75). A subgroup analysis of healthy and KC eyes with comparable mean CCT and IOP highlighted a statistically significant difference in mean DA (KC 1.25 ± 0.08 mm, thin healthy 1.13 ± 0.09 mm, P = 0.006). Receiver-operating characteristic analysis showed an area under the curve of 0.77 (95% CI 0.61-0.93, P = 0.006) but no ideal cutoff value for DA. Key parameters assessed by the CST are repeatable. Keratoconus is associated with greater DA than in healthy eyes, even when controlled for CCT and IOP. Deformation amplitude may be a useful adjunct in keratoconus assessment and monitoring, but cannot solely discriminate between healthy and keratoconic corneas. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Advanced sampling techniques for hand-held FT-IR instrumentation

Science.gov (United States)

Arnó, Josep; Frunzi, Michael; Weber, Chris; Levy, Dustin

2013-05-01

FT-IR spectroscopy is the technology of choice to identify solid and liquid phase unknown samples. The challenging ConOps in emergency response and military field applications require a significant redesign of the stationary FT-IR bench-top instruments typically used in laboratories. Specifically, field portable units require high levels of resistance against mechanical shock and chemical attack, ease of use in restrictive gear, extreme reliability, quick and easy interpretation of results, and reduced size. In the last 20 years, FT-IR instruments have been re-engineered to fit in small suitcases for field portable use and recently further miniaturized for handheld operation. This article introduces the HazMatID™ Elite, a FT-IR instrument designed to balance the portability advantages of a handheld device with the performance challenges associated with miniaturization. In this paper, special focus will be given to the HazMatID Elite's sampling interfaces optimized to collect and interrogate different types of samples: accumulated material using the on-board ATR press, dispersed powders using the ClearSampler™ tool, and the touch-to-sample sensor for direct liquid sampling. The application of the novel sample swipe accessory (ClearSampler) to collect material from surfaces will be discussed in some detail. The accessory was tested and evaluated for the detection of explosive residues before and after detonation. Experimental results derived from these investigations will be described in an effort to outline the advantages of this technology over existing sampling methods.

Xsense: using nanotechnology to combine detection methods for high sensitivity handheld explosives detectors

DEFF Research Database (Denmark)

Schmidt, Michael Stenbæk; Kostesha, Natalie; Bosco, Filippo

2010-01-01

In an effort to produce a handheld explosives sensor the Xsense project has been initiated at the Technical University of Denmark in collaboration with a number of partners. Using micro- and nano technological approaches it will be attempted to integrate four detection principles into a single de...

Standard guide to In-Plant performance evaluation of Hand-Held SNM monitors

CERN Document Server

American Society for Testing and Materials. Philadelphia

1999-01-01

1.1 This guide is one of a series on the application and evaluation of special nuclear material (SNM) monitors. Other guides in the series are listed in Section 2, and the relationship of in-plant performance evaluation to other procedures described in the series is illustrated in Fig. 1. Hand-held SNM monitors are described in of Guide C1112, and performance criteria illustrating their capabilities can be found in Appendix X1. 1.2 The purpose of this guide to in-plant performance evaluation is to provide a comparatively rapid procedure to verify that a hand-held SNM monitor performs as expected for detecting SNM or alternative test sources or to disclose the need for repair. The procedure can be used as a routine operational evaluation or it can be used to verify performance after a monitor is calibrated. 1.3 In-plant performance evaluations are more comprehensive than daily functional tests. They take place less often, at intervals ranging from weekly to once every three months, and derive their result fr...

Strength Measurements in Acute Hamstring Injuries: Intertester Reliability and Prognostic Value of Handheld Dynamometry

NARCIS (Netherlands)

Reurink, Gustaaf; Goudswaard, Gert Jan; Moen, Maarten H.; Tol, Johannes L.; Verhaar, Jan A. N.; Weir, Adam

2016-01-01

Study Design Cohort study, repeated measures. Background Although hamstring strength measurements are used for assessing prognosis and monitoring recovery after hamstring injury, their actual clinical relevance has not been established. Handheld dynamometry (HHD) is a commonly used method of

Epidemiology of Handheld Cell Phone Use While Driving: A Study from a South Indian City.

Science.gov (United States)

Majgi, Sumanth Mallikarjuna; AiswaryaLakshmi, A S

2018-01-01

Using cell phones while driving contribute to distractions which can potentially cause minor or major road traffic injuries and also stress among other drivers. With this background, the study was done to ascertain the proportion of handheld cell phone use while driving among road users in Mysore city and also patterns of the use by the day of week, type of road, and type of vehicle. The study was conducted in Mysore, Karnataka, India. Four stretches of roads were observed thrice daily for 1 week. The total number of vehicles passing through the stretch and the number and characteristics of drivers using hand-held cell was noted. Pearson's Chi-square test was used to ascertain the significance of the difference in proportions. The overall proportion of cell phone users was calculated as 1.41/100 vehicles. The observed use of handheld cell phones was 1.78 times higher on nonbusy roads than busy roads ( Χ 2 = 25.79, P phone users were driving a two wheeler, the proportion being 50.5% in busy roads, and 67% in nonbusy roads. There was no difference in the proportion of cell phone use by time of the day or across different days of the week. The proportion of drivers who use cell phones is found to be relatively lower, and use of cell phones was higher on nonbusy roads.

Balancing fast-rotating parts of hand-held machine drive

Science.gov (United States)

Korotkov, V. S.; Sicora, E. A.; Nadeina, L. V.; Yongzheng, Wang

2018-03-01

The article considers the issues related to the balancing of fast rotating parts of the hand-held machine drive including a wave transmission with intermediate rolling elements, which is constructed on the basis of the single-phase collector motor with a useful power of 1 kW and a nominal rotation frequency of 15000 rpm. The forms of balancers and their location are chosen. The method of balancing is described. The scheme for determining of residual unbalance in two correction planes is presented. Measurement results are given in tables.

Comparison of Wearable Optical See-through and Handheld Devices as Platform for an Augmented Reality Museum Guide

DEFF Research Database (Denmark)

Serubugo, Sule; Skantarova, Denisa; Nielsen, Lasse Kjærsgård

2017-01-01

Self-service guides are a common way of providing information about artworks exhibited in museums. Modern advances in handheld mobile applications and wearable optical see-through devices that use augmented reality offer new ways of designing museum guides that are more engaging and interactive...... than traditional self-service guides such as written descriptions or audio guides. In this study we compare wearable (smart glasses) and handheld (smartphone) devices as a platform for an augmented reality museum guide. We have developed a museum guide for both a smartphone and smart glasses that can...... of potentials of these platforms as augmented reality museum guides and suggest promising future work....

Hand-held cell phone use while driving legislation and observed driver behavior among population sub-groups in the United States

OpenAIRE

Rudisill, Toni M.; Zhu, Motao

2017-01-01

Abstract Background Cell phone use behaviors are known to vary across demographic sub-groups and geographic locations. This study examined whether universal hand-held calling while driving bans were associated with lower road-side observed hand-held cell phone conversations across drivers of different ages (16–24, 25–59, ≥60 years), sexes, races (White, African American, or other), ruralities (suburban, rural, or urban), and regions (Northeast, Midwest, South, and West). Methods Data from the...

[Correlation between Goldmann and non-contact tonometry based on corneal thickness].

Science.gov (United States)

Schepens, G; Urier, N; Bechetoille, A; De Potter, P

2001-01-01

In this transversal study, we measure the intra ocular pressure by means of the Goldmann tonometer and a Non-Contact tonometer along with the central cornea thickness in 136 eyes of 73 patients. The statistical analysis of the collected data doesn't allow us to establish a correlation between the variation of the corneal thickness and the difference between the Goldmann tonometer and Non-Contact tonometer measures. The relative precision of the Non-Contact tonometer compared with the Goldmann tonometer doesn't seem influenced by the central cornea thickness.

Effects of a Driver Cellphone Ban on Overall, Handheld, and Hands-Free Cellphone Use While Driving: New Evidence from Canada.

Science.gov (United States)

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.

Rapid and automatic chemical identification of the medicinal flower buds of Lonicera plants by the benchtop and hand-held Fourier transform infrared spectroscopy

Science.gov (United States)

Chen, Jianbo; Guo, Baolin; Yan, Rui; Sun, Suqin; Zhou, Qun

2017-07-01

With the utilization of the hand-held equipment, Fourier transform infrared (FT-IR) spectroscopy is a promising analytical technique to minimize the time cost for the chemical identification of herbal materials. This research examines the feasibility of the hand-held FT-IR spectrometer for the on-site testing of herbal materials, using Lonicerae Japonicae Flos (LJF) and Lonicerae Flos (LF) as examples. Correlation-based linear discriminant models for LJF and LF are established based on the benchtop and hand-held FT-IR instruments. The benchtop FT-IR models can exactly recognize all articles of LJF and LF. Although a few LF articles are misjudged at the sub-class level, the hand-held FT-IR models are able to exactly discriminate LJF and LF. As a direct and label-free analytical technique, FT-IR spectroscopy has great potential in the rapid and automatic chemical identification of herbal materials either in laboratories or in fields. This is helpful to prevent the spread and use of adulterated herbal materials in time.

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

Science.gov (United States)

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 ...

Evaluation of a focussed protocol for hand-held echocardiography and computer-assisted auscultation in detecting latent rheumatic heart disease in scholars.

Science.gov (United States)

Zühlke, Liesl J; Engel, Mark E; Nkepu, Simpiwe; Mayosi, Bongani M

2016-08-01

Introduction Echocardiography is the diagnostic test of choice for latent rheumatic heart disease. The utility of echocardiography for large-scale screening is limited by high cost, complex diagnostic protocols, and time to acquire multiple images. We evaluated the performance of a brief hand-held echocardiography protocol and computer-assisted auscultation in detecting latent rheumatic heart disease with or without pathological murmur. A total of 27 asymptomatic patients with latent rheumatic heart disease based on the World Heart Federation criteria and 66 healthy controls were examined by standard cardiac auscultation to detect pathological murmur. Hand-held echocardiography using a focussed protocol that utilises one view - that is, the parasternal long-axis view - and one measurement - that is, mitral regurgitant jet - and a computer-assisted auscultation utilising an automated decision tool were performed on all patients. The sensitivity and specificity of computer-assisted auscultation in latent rheumatic heart disease were 4% (95% CI 1.0-20.4%) and 93.7% (95% CI 84.5-98.3%), respectively. The sensitivity and specificity of the focussed hand-held echocardiography protocol for definite rheumatic heart disease were 92.3% (95% CI 63.9-99.8%) and 100%, respectively. The test reliability of hand-held echocardiography was 98.7% for definite and 94.7% for borderline disease, and the adjusted diagnostic odds ratios were 1041 and 263.9 for definite and borderline disease, respectively. Computer-assisted auscultation has extremely low sensitivity but high specificity for pathological murmur in latent rheumatic heart disease. Focussed hand-held echocardiography has fair sensitivity but high specificity and diagnostic utility for definite or borderline rheumatic heart disease in asymptomatic patients.

Hand-held tidal breathing nasal nitric oxide measurement--a promising targeted case-finding tool for the diagnosis of primary ciliary dyskinesia

DEFF Research Database (Denmark)

Marthin, June Kehlet; Nielsen, Kim Gjerum

2013-01-01

BACKGROUND: Nasal nitric oxide (nNO) measurement is an established first line test in the work-up for primary ciliary dyskinesia (PCD). Tidal breathing nNO (TB-nNO) measurements require minimal cooperation and are potentially useful even in young children. Hand-held NO devices are becoming...... increasingly widespread for asthma management. Therefore, we chose to assess whether hand-held TB-nNO measurements reliably discriminate between PCD, and Healthy Subjects (HS) and included Cystic Fibrosis (CF) patients as a disease control group known to have intermediate nNO levels. METHODS: In this cross...... sectional, single centre, single occasion, proof-of-concept study in children and adults with PCD and CF, and in HS we compared feasibility, success rates, discriminatory capacity, repeatability and agreement between a hand-held electrochemical device equipped with a nNO software application sampling...

Survey reveals public open to ban on hand-held cell phone use and texting.

Science.gov (United States)

2013-01-01

A study performed by the Bureau of Transportation Statistics (BTS) reveals that the public is open to a ban on hand-held cell phone use while driving. The study is based on data from 2009s Omnibus Household Survey (OHS), which is administered by B...

Algorithms for a hand-held miniature x-ray fluorescence analytical instrument

International Nuclear Information System (INIS)

Elam, W.T.; Newman, D.; Ziemba, F.

1998-01-01

The purpose of this joint program was to provide technical assistance with the development of a Miniature X-ray Fluorescence (XRF) Analytical Instrument. This new XRF instrument is designed to overcome the weaknesses of spectrometers commercially available at the present time. Currently available XRF spectrometers (for a complete list see reference 1) convert spectral information to sample composition using the influence coefficients technique or the fundamental parameters method. They require either a standard sample with composition relatively close to the unknown or a detailed knowledge of the sample matrix. They also require a highly-trained operator and the results often depend on the capabilities of the operator. In addition, almost all existing field-portable, hand-held instruments use radioactive sources for excitation. Regulatory limits on such sources restrict them such that they can only provide relatively weak excitation. This limits all current hand-held XRF instruments to poor detection limits and/or long data collection times, in addition to the licensing requirements and disposal problems for radioactive sources. The new XRF instrument was developed jointly by Quantrad Sensor, Inc., the Naval Research Laboratory (NRL), and the Department of Energy (DOE). This report describes the analysis algorithms developed by NRL for the new instrument and the software which embodies them

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

Science.gov (United States)

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…

Hand-held spectrophotometer design for textile fabrics

Science.gov (United States)

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.

Corneal Vibrations during Intraocular Pressure Measurement with an Air-Puff Method

Directory of Open Access Journals (Sweden)

Robert Koprowski

2018-01-01

Full Text Available Introduction. The paper presents a commentary on the method of analysis of corneal vibrations occurring during eye pressure measurements with air-puff tonometers, for example, Corvis. The presented definition and measurement method allow for the analysis of image sequences of eye responses—cornea deformation. In particular, the outer corneal contour and sclera fragments are analysed, and 3D reconstruction is performed. Methods. On this basis, well-known parameters such as eyeball reaction or corneal response are determined. The next steps of analysis allow for automatic and reproducible separation of four different corneal vibrations. These vibrations are associated with (1 the location of the maximum of cornea deformation; (2 the cutoff area measured in relation to the cornea in a steady state; (3 the maximum of peaks occurring between applanations; and (4 the other characteristic points of the corneal contour. Results. The results obtained enable (1 automatic determination of the amplitude of vibrations; (2 determination of the frequency of vibrations; and (3 determination of the correlation between the selected types of vibrations. Conclusions. These are diagnostic features that can be directly applied clinically for new and archived data.

Assessment of corneal dynamics with high-speed swept source Optical Coherence Tomography combined with an air puff system

Science.gov (United States)

Alonso-Caneiro, David; Karnowski, Karol; Kaluzny, Bartlomiej J.; Kowalczyk, Andrzej; Wojtkowski, Maciej

2011-07-01

We present a novel method and instrument for in vivo imaging and measurement of the human corneal dynamics during an air puff. The instrument is based on high-speed swept source optical coherence tomography (ssOCT) combined with a custom adapted air puff chamber from a non-contact tonometer, which uses an air stream to deform the cornea in a non-invasive manner. During the short period of time that the deformation takes place, the ssOCT acquires multiple A-scans in time (M-scan) at the center of the air puff, allowing observation of the dynamics of the anterior and posterior corneal surfaces as well as the anterior lens surface. The dynamics of the measurement are driven by the biomechanical properties of the human eye as well as its intraocular pressure. Thus, the analysis of the M-scan may provide useful information about the biomechanical behavior of the anterior segment during the applanation caused by the air puff. An initial set of controlled clinical experiments are shown to comprehend the performance of the instrument and its potential applicability to further understand the eye biomechanics and intraocular pressure measurements. Limitations and possibilities of the new apparatus are discussed.

Exploring field-of-view non-uniformities produced by a hand-held spectroradiometer

Directory of Open Access Journals (Sweden)

Tamir Caras

2011-01-01

Full Text Available The shape of a spectroradiometer’s field of view (FOV affects the way spectral measurements are acquired. Knowing this property is a prerequisite for the correct use of the spectrometer. If the substrate is heterogeneous, the ability to accurately know what is being measured depends on knowing the FOV location, shape, spectral and spatial sensitivity. The GER1500 is a hand-held spectrometer with a fixed lens light entry slit and has a laser guide that allows control over the target by positioning the entire unit. In the current study, the FOV of the GER1500 was mapped and analysed. The spectral and spatial non-uniformities of the FOV were examined and were found to be spectrally independent. The relationship between the FOV and the built-in laser guide was tested and found to have a linear displacement dependent on the distance to the target. This allows an accurate prediction of the actual FOV position. A correction method to improve the agreement between the expected and measured reflectance over heterogeneous targets was developed and validated. The methods described are applicable and may be of use with other hand-held spectroradiometers.

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

Science.gov (United States)

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... United States after importation of certain wireless communications system server software, wireless...

Applying Hand-Held 3D Printing Technology to the Teaching of VSEPR Theory

Science.gov (United States)

Dean, Natalie L.; Ewan, Corrina; McIndoe, J. Scott

2016-01-01

The use of hand-held 3D printing technology provides a unique and engaging approach to learning VSEPR theory by enabling students to draw three-dimensional depictions of different molecular geometries, giving them an appreciation of the shapes of the building blocks of complex molecular structures. Students are provided with 3D printing pens and…

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

Science.gov (United States)

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.

Discrimination of Pigments of Microalgae, Bacteria and Yeasts Using Lightweight Handheld Raman Spectrometers: Prospects for Astrobiology

Science.gov (United States)

Jehlicka, J.; Osterrothova, K.; Nedbalova, L.; Gunde-Cimerman, N.; Oren, A.

2014-06-01

Handheld Raman instrumentation with 532 nm lasers can be used to distinguish carotenoids of autotrophic microalgae, purple sulfur bacteria, halophilic Archaea and pigmented yeasts. Pigments are proposed as biomarkers for astrobiology of Mars.

Elbow joint position sense after neuromuscular training with handheld vibration.

Science.gov (United States)

Tripp, Brady L; Faust, Donald; Jacobs, Patrick

2009-01-01

Clinicians use neuromuscular control exercises to enhance joint position sense (JPS); however, because standardizing such exercises is difficult, validations of their use are limited. To evaluate the acute effects of a neuromuscular training exercise with a handheld vibrating dumbbell on elbow JPS acuity. Crossover study. University athletic training research laboratory. Thirty-one healthy, college-aged volunteers (16 men, 15 women, age = 23 + or - 3 years, height = 173 + or - 8 cm, mass = 76 + or - 14 kg). We measured and trained elbow JPS using an electromagnetic tracking device that provided auditory and visual biofeedback. For JPS testing, participants held a dumbbell and actively identified the target elbow flexion angle (90 degrees ) using the software-generated biofeedback, followed by 3 repositioning trials without feedback. Each neuromuscular training protocol included 3 exercises during which participants held a 2.55-kg dumbbell vibrating at 15, 5, or 0 Hz and used software-generated biofeedback to locate and maintain the target elbow flexion angle for 15 seconds. We calculated absolute (accuracy) and variable (variability) errors using the differences between target and reproduced angles. Training protocols using 15-Hz vibration enhanced accuracy and decreased variability of elbow JPS (P or = .200). Our results suggest these neuromuscular control exercises, which included low-magnitude, low-frequency handheld vibration, may enhance elbow JPS. Future researchers should examine vibration of various durations and frequencies, should include injured participants and functional multijoint and multiplanar measures, and should examine long-term effects of training protocols on JPS and injury.

A Study of the Use of a Handheld Computer Algebra System in Discrete Mathematics

Science.gov (United States)

Powers, Robert A.; Allison, Dean E.; Grassl, Richard M.

2005-01-01

This study investigated the impact of the TI-92 handheld Computer Algebra System (CAS) on student achievement in a discrete mathematics course. Specifically, the researchers examined the differences between a CAS section and a control section of discrete mathematics on students' in-class examinations. Additionally, they analysed student approaches…

Comparing handheld and hands-free cell phone usage behaviors while driving.

Science.gov (United States)

Soccolich, Susan A; Fitch, Gregory M; Perez, Miguel A; Hanowski, Richard J

2014-01-01

The goal of this study was to compare cell phone usage behaviors while driving across 3 types of cell phones: handheld (HH) cell phones, portable hands-free (PHF) cell phones, and integrated hands-free (IHF) cell phones. Naturalistic driving data were used to observe HH, PHF, and IHF usage behaviors in participants' own vehicles without any instructions or manipulations by researchers. In addition to naturalistic driving data, drivers provided their personal cell phone call records. Calls during driving were sampled and observed in naturalistically collected video. Calls were reviewed to identify cell phone type used for, and duration of, cell phone subtasks, non-cell phone secondary tasks, and other use behaviors. Drivers in the study self-identified as HH, PHF, or IHF users if they reported using that cell phone type at least 50% of the time. However, each sampled call was classified as HH, PHF, or IHF if the talking/listening subtask was conducted using that cell phone type, without considering the driver's self-reported group. Drivers with PHF or IHF systems also used HH cell phones (IHF group used HH cell phone in 53.2% of the interactions, PHF group used HH cell phone for 55.5% of interactions). Talking/listening on a PHF phone or an IHF phone was significantly longer than talking/listening on an HH phone (P phone call task for HH phones was significantly longer in duration than the end phone call task for PHF and IHF phones. Of all the non-cell phone-related secondary tasks, eating or drinking was found to occur significantly more often during IHF subtasks (0.58%) than in HH subtasks (0.15%). Drivers observed to reach for their cell phone mostly kept their cell phone in the cup holder (36.3%) or in their seat or lap (29.0% of interactions); however, some observed locations may have required drivers to move out of position. Hands-free cell phone technologies reduce the duration of cell phone visual-manual tasks compared to handheld cell phones. However

Technological characteristics of digital video broadcasting: Handheld standard DVB-H

Directory of Open Access Journals (Sweden)

Andreja B. Samčović

2011-07-01

Full Text Available This paper gives an overview of the Digital Video Broadcasting - Handheld standard DVB-H, as a part of the DVB Project. This standard is based on the previous standard DVB-T, which was developed for the terrestrial digital television. The ways of DVB-H signal transmission are also described. Development of advanced technology enabled the digital video broadcasting over wireless portable terminals. This paper discusses the key technological features of the DVB-H standard, such as: time slicing, forward error correction, 4K mode and in-depth interleavers.

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

Science.gov (United States)

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...

Potential role of a new hand-held miniature gamma camera in performing minimally invasive parathyroidectomy

Energy Technology Data Exchange (ETDEWEB)

Ortega, Joaquin; Lledo, Salvador [University of Valencia, Clinic University Hospital, Department of Surgery, Valencia (Spain); Ferrer-Rebolleda, Jose [Clinic University Hospital, Department of Nuclear Medicine, Valencia (Spain); Cassinello, Norberto [Clinic University Hospital, Unit of Endocrinologic and Bariatric Surgery, Valencia (Spain)

2007-02-15

Sestamibi scans have increased the use of minimally invasive parathyroidectomy (MIP) to treat primary hyperparathyroidism (PHPT) when caused by a parathyroid single adenoma. The greatest concern for surgeons remains the proper identification of pathological glands in a limited surgical field. We have studied the usefulness of a new hand-held miniature gamma camera (MGC) when used intraoperatively to locate parathyroid adenomas. To our knowledge this is the first report published on this subject in the scientific literature. Five patients with PHPT secondary to a single adenoma, positively diagnosed by preoperative sestamibi scans, underwent a MIP. A gamma probe for radioguided surgery and the new hand-held MGC were used consecutively to locate the pathological glands. This new MGC has a module composed of a high-resolution interchangeable collimator and a CsI(Na) scintillating crystal. It has dimensions of around 15 cm x 8 cm x 9 cm and weighs 1 kg. The intraoperative assay of PTH (ioPTH) was used to confirm the complete resection of pathological tissue. All cases were operated on successfully by a MIP. The ioPTH confirmed the excision of all pathological tissues. The MGC proved its usefulness in all patients, even in a difficult case in which the first attempt with the gamma probe failed. In all cases it offered real-time accurate intraoperative images. The hand-held MGC is a useful instrument in MIP for PHPT. It may be used to complement the standard tools used to date, or may even replace them, at least in selected cases of single adenomas. (orig.)

Potential role of a new hand-held miniature gamma camera in performing minimally invasive parathyroidectomy

International Nuclear Information System (INIS)

Ortega, Joaquin; Lledo, Salvador; Ferrer-Rebolleda, Jose; Cassinello, Norberto

2007-01-01

Sestamibi scans have increased the use of minimally invasive parathyroidectomy (MIP) to treat primary hyperparathyroidism (PHPT) when caused by a parathyroid single adenoma. The greatest concern for surgeons remains the proper identification of pathological glands in a limited surgical field. We have studied the usefulness of a new hand-held miniature gamma camera (MGC) when used intraoperatively to locate parathyroid adenomas. To our knowledge this is the first report published on this subject in the scientific literature. Five patients with PHPT secondary to a single adenoma, positively diagnosed by preoperative sestamibi scans, underwent a MIP. A gamma probe for radioguided surgery and the new hand-held MGC were used consecutively to locate the pathological glands. This new MGC has a module composed of a high-resolution interchangeable collimator and a CsI(Na) scintillating crystal. It has dimensions of around 15 cm x 8 cm x 9 cm and weighs 1 kg. The intraoperative assay of PTH (ioPTH) was used to confirm the complete resection of pathological tissue. All cases were operated on successfully by a MIP. The ioPTH confirmed the excision of all pathological tissues. The MGC proved its usefulness in all patients, even in a difficult case in which the first attempt with the gamma probe failed. In all cases it offered real-time accurate intraoperative images. The hand-held MGC is a useful instrument in MIP for PHPT. It may be used to complement the standard tools used to date, or may even replace them, at least in selected cases of single adenomas. (orig.)

Strength and Pain Threshold Handheld Dynamometry Test Reliability in Patellofemoral Pain.

Science.gov (United States)

van der Heijden, R A; Vollebregt, T; Bierma-Zeinstra, S M A; van Middelkoop, M

2015-12-01

Patellofemoral pain syndrome (PFPS), characterized by peri- and retropatellar pain, is a common disorder in young, active people. The etiology is unclear; however, quadriceps strength seems to be a contributing factor, and sensitization might play a role. The study purpose is determining the inter-rater reliability of handheld dynamometry to test both quadriceps strength and pressure pain threshold (PPT), a measure for sensitization, in patients with PFPS. This cross-sectional case-control study comprises 3 quadriceps strength and one PPT measurements performed by 2 independent investigators in 22 PFPS patients and 16 matched controls. Inter-rater reliability was analyzed using intraclass correlation coefficients (ICC) and Bland-Altman plots. Inter-rater reliability of quadriceps strength testing was fair to good in PFPS patients (ICC=0.72) and controls (ICC=0.63). Bland-Altman plots showed an increased difference between assessors when average quadriceps strength values exceeded 250 N. Inter-rater reliability of PPT was excellent in patients (ICC=0.79) and fair to good in controls (ICC=0.52). Handheld dynamometry seems to be a reliable method to test both quadriceps strength and PPT in PFPS patients. Inter-rater reliability was higher in PFPS patients compared to control subjects. With regard to quadriceps testing, a higher variance between assessors occurs when quadriceps strength increases. © Georg Thieme Verlag KG Stuttgart · New York.

A handheld open-field infant keratometer (an american ophthalmological society thesis).

Science.gov (United States)

Miller, Joseph M

2010-12-01

To design and evaluate a new infant keratometer that incorporates an unobstructed view of the infant with both eyes (open-field design). The design of the open-field infant keratometer is presented, and details of its construction are given. The design incorporates a single-ring keratoscope for measurement of corneal astigmatism over a 4-mm region of the cornea and includes a rectangular grid target concentric within the ring to allow for the study of higher-order aberrations of the eye. In order to calibrate the lens and imaging system, a novel telecentric test object was constructed and used. The system was bench calibrated against steel ball bearings of known dimensions and evaluated for accuracy while being used in handheld mode in a group of 16 adult cooperative subjects. It was then evaluated for testability in a group of 10 infants and toddlers. Results indicate that while the device achieved the goal of creating an open-field instrument containing a single-ring keratoscope with a concentric grid array for the study of higher-order aberrations, additional work is required to establish better control of the vertex distance. The handheld open-field infant keratometer demonstrates testability suitable for the study of infant corneal astigmatism. Use of collimated light sources in future iterations of the design must be incorporated in order to achieve the accuracy required for clinical investigation.

Absorption Related to Hand-Held Devices in Data Mode

DEFF Research Database (Denmark)

Andersen, Jørgen Bach; Nielsen, Jesper Ødum; Pedersen, Gert F.

2016-01-01

The human body has an influence on the radiation from handheld devices like smartphones, tablets and laptops, part of the energy is absorbed and the spatial distribution of the radiated part is modified. Previous studies of whole body absorp- tion have mainly been numerical or related to talk mode....... In the present paper an experimental study involving four volunteers and three different devices is performed from 0.5 to 3 GHz. The devices are a laptop, a tablet, and a smartphone all held in the lap. The 3D distribution of radiation is measured. Comparing the integrated power in the case of a person present...

A sensitive, handheld vapor sensor based on microcantilevers

Science.gov (United States)

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.

A handheld optical device for skin profile measurement

Science.gov (United States)

Sun, Jiuai; Liu, Xiaojin

2018-04-01

This paper describes a portable optical scanning device designed for skin surface measurement on both colour and 3D geometry through a relative easy and cost effective multiple light source photometric stereo method. The validation of colour recovered had been verified through its application on skin lesion segmentation in our early work. This paper focuses on the reconstructed topographic data which are subject to further evaluation and advancement. The evaluation work takes the skin in vitro as an application scenario and compares the experimental result to that obtained by using a commercial product. The experiments show that this handheld device can measure the skin profile significantly closer to that of the ground truth and have the additional function of skin colour recovery.

Modalities of Tonometry and their Accuracy with Respect to Corneal Thickness and Irregularities

Science.gov (United States)

De Moraes, Carlos Gustavo V.; Prata, Tiago S.; Liebmann, Jeffrey; Ritch, Robert

2010-01-01

Recent advances in tonometry have led to the development of a number of devices with differing clinical applications. Their role in cases of abnormal corneal thickness and surface irregularities is particularly important, as inaccurate estimation of the true intraocular pressure (IOP) in such cases may lead to suboptimal evaluation. The purpose of the present review was to evaluate the accuracy of the most widely used devices in cases of corneal thickness and surface irregularities, based on a survey of the published literature. The analysis was based on a Medline search focusing mainly on papers that have evaluated the devices’ accuracy with respect to corneal thickness and irregularities. Nine device types (Goldmann tonometer, Tono-Pen, Perkins tonometer, Ocular Response Analyzer, non-contact tonometer, pneumatonometer, I-Care rebound tonometer, Pascal dynamic contour tonometer (DCT) and Phosphene tonometer) were described in detail. Moreover, the physical principles and major utility of each tonometer were compared. Each of the many different commercially available tonometers has specific advantages and disadvantages. New non-invasive technologies are getting closer to a precise estimation of the true IOP. However, among all tonometers, none is highly accurate when both corneal thickness and surface irregularities are present. Fifty years after its development, Goldmann tonometry remains the gold standard to which all other devices are compared.

Contact lens assisted imaging with integrated flexible handheld probe for glaucoma diagnosis

Science.gov (United States)

Hong, Xun Jie Jeesmond; V. K., Shinoj; Murukeshan, V. M.; Baskaran, M.; Aung, Tin

2017-06-01

Angle closure glaucoma accounts for majority of the bilateral blindness in Asian countries such as Singapore, China, and India. Abnormalities in the optic nerve and aqueous outflow system are the most indicative clinical hallmarks for glaucoma of this clinical subtype. Traditional photographic imaging techniques to assess the drainage angle are contact based, and may expose patients to risk of corneal abrasion and infections. In addition, these procedures require the use of viscous ophthalmic gels as coupling medium to overcome the phenomenon of total internal reflection at the tear-air interface. In this paper, we propose an integrated flexible handheld probe consisting of a micro color CCD video camera and white light LEDs. The handheld probe is able to capture images of the fundus and opposite iridocorneal angle when placed at the central cornea or limbus respectively. Here, we propose the use of hydrogel contact lens as an index matching medium and better protective barrier, as an alternative to conventional ophthalmic gels. The proposed imaging system and methodology has been successfully tested on porcine eye samples, ex vivo. With its high repeatability, reproducibility, and a good safety profile, it is believed that the proposed imaging system and methodology will complement existing imaging modalities in the diagnosis and management of glaucoma.

Use of handheld X-ray fluorescence spectrometry units for identification of arsenic in treated wood

Energy Technology Data Exchange (ETDEWEB)

Block, Colleen N. [University of Miami, Department of Civil, Architectural, and Environmental Engineering, P.O. Box 248294, McArthur Building, Coral Gables, FL 33124-0630 (United States); Shibata, Tomoyuki [University of Miami, Department of Civil, Architectural, and Environmental Engineering, P.O. Box 248294, McArthur Building, Coral Gables, FL 33124-0630 (United States); Solo-Gabriele, Helena M. [University of Miami, Department of Civil, Architectural, and Environmental Engineering, P.O. Box 248294, McArthur Building, Coral Gables, FL 33124-0630 (United States)]. E-mail: hmsolo@miami.edu; Townsend, Timothy G. [University of Florida, Department of Environmental Engineering Sciences, Gainesville, FL 32611-6450 (United States)

2007-07-15

The objective of this study was to evaluate the performance of handheld XRF analyzers on wood that has been treated with a preservative containing arsenic. Experiments were designed to evaluate precision, detection limit, effective depth of analysis, and accuracy of the XRF arsenic readings. Results showed that the precision of the XRF improved with increased sample concentration and longer analysis times. Reported detection limits decreased with longer analysis times to values of less than 1 mg/kg or 18 mg/kg, depending on the model used. The effective depth of analysis was within the top 1.2 cm and 2.0 cm of sample for wood containing natural gradients of chemical preservative and concentration extremes, respectively. XRF results were found to be 1.5-2.3 times higher than measurements from traditional laboratory analysis. Equations can be developed to convert XRF values to results which are consistent with traditional laboratory testing. - Handheld XRF analyzers provided quantitative results for the amount of arsenic within preservative-treated wood.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Font size and viewing distance of handheld smart phones.

Science.gov (United States)

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

Pyxis handheld polarimetric imager

Science.gov (United States)

Chenault, David B.; Pezzaniti, J. Larry; Vaden, Justin P.

2016-05-01

The instrumentation for measuring infrared polarization signatures has seen significant advancement over the last decade. Previous work has shown the value of polarimetric imagery for a variety of target detection scenarios including detection of manmade targets in clutter and detection of ground and maritime targets while recent work has shown improvements in contrast for aircraft detection and biometric markers. These data collection activities have generally used laboratory or prototype systems with limitations on the allowable amount of target motion or the sensor platform and usually require an attached computer for data acquisition and processing. Still, performance and sensitivity have been steadily getting better while size, weight, and power requirements have been getting smaller enabling polarimetric imaging for a greater or real world applications. In this paper, we describe Pyxis®, a microbolometer based imaging polarimeter that produces live polarimetric video of conventional, polarimetric, and fused image products. A polarization microgrid array integrated in the optical system captures all polarization states simultaneously and makes the system immune to motion artifacts of either the sensor or the scene. The system is battery operated, rugged, and weighs about a quarter pound, and can be helmet mounted or handheld. On board processing of polarization and fused image products enable the operator to see polarimetric signatures in real time. Both analog and digital outputs are possible with sensor control available through a tablet interface. A top level description of Pyxis® is given followed by performance characteristics and representative data.

Using handheld devices for real-time wireless teleconsultation.

Science.gov (United States)

Banitsas, K A; Georgiadis, P; Tachakra, S; Cavouras, D

2004-01-01

Recent advances in the hardware of handheld devices, opened up the way for newer applications in the healthcare sector, and more specifically, in the teleconsultation field. Out of these devices, this paper focuses on the services that personal digital assistants and smartphones can provide to improve the speed, quality and ease of delivering a medical opinion from a distance and laying the ground for an all-wireless hospital. In that manner, PDAs were used to wirelessly support the viewing of digital imaging and communication in medicine (DICOM) images and to allow for mobile videoconferencing while within the hospital. Smartphones were also used to carry still images, multiframes and live video outside the hospital. Both of these applications aimed at increasing the mobility of the consultant while improving the healthcare service.

Gamma-ray detectors for intelligent, hand-held radiation monitors

International Nuclear Information System (INIS)

Fehlau, P.E.

1983-01-01

Small radiation detectors based on HgI 2 , bismuth germanate (BGO), plastic, or NaI(Tl) detector materials were evaluated for use in small, lighweight radiation monitors. The two denser materials, HgI 2 and BGO, had poor resolution at low-energy and thus performed less well than NaI(Tl) in detecting low-energy gamma rays from bare, enriched uranium. The plastic scintillator, a Compton recoil detector, also performed less well at low gamma-ray energy. Two small NaI(Tl) detectors were suitable for detecting bare uranium and sheilded plutonium. One became part of a new lightweight hand-held monitor and the other found uses as a pole-mounted detector for monitoring hard-to-reach locations

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

Science.gov (United States)

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.

The Xsense project: The application of an intelligent sensor array for high sensitivity handheld explosives detectors

DEFF Research Database (Denmark)

Kostesha, Natalie; Schmidt, Michael Stenbæk; Bosco, Filippo

2011-01-01

Multiple independent sensors are used in security and military applications in order to increase sensitivity, selectivity and data reliability. The Xsense project has been initiated at the Technical University of Denmark in collaboration with a number of partners in an effort to produce a handheld...

Introducing Handheld Computing for Interactive Medical Education

Directory of Open Access Journals (Sweden)

Joseph Finkelstein

2005-04-01

Full Text Available The goals of this project were: (1 development of an interactive multimedia medical education tool (CO-ED utilizing modern features of handheld computing (PDA and major constructs of adult learning theories, and (2 pilot testing of the computer-assisted education in residents and clinicians. Comparison of the knowledge scores using paired t-test demonstrated statistically significant increase in subject knowledge (p<0.01 after using CO-ED. Attitudinal surveys were analyzed by total score (TS calculation represented as a percentage of a maximal possible score. The mean TS was 74.5±7.1%. None of the subjects (N=10 had TS less than 65% and in half of the subjects (N=5 TS was higher than 75%. Analysis of the semi-structured in-depth interviews showed strong support of the study subjects in using PDA as an educational tool, and high acceptance of CO-ED user interface. We concluded that PDA have a significant potential as a tool for clinician education.

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

Science.gov (United States)

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.

A Mobile Mixed-Reality Environment for Children's Storytelling Using a Handheld Projector and a Robot

Science.gov (United States)

Sugimoto, Masanori

2011-01-01

This paper describes a system called GENTORO that uses a robot and a handheld projector for supporting children's storytelling activities. GENTORO differs from many existing systems in that children can make a robot play their own story in a physical space augmented by mixed-reality technologies. Pilot studies have been conducted to clarify the…

Handheld Micromanipulator for Robot-Assisted Stapes Footplate Surgery

Science.gov (United States)

Grande, Gonzalo Montes; Knisely, Anna J.; Becker, Brian C.; Yang, Sungwook; Hirsch, Barry E.; Riviere, Cameron N.

2012-01-01

Stapes footplate surgery is complex and delicate. This surgery is carried out in the middle ear to improve hearing. High accuracy is required to avoid critical tissues and structures near the surgical worksite. By suppressing the surgeon’s tremor during the operation, accuracy can be improved. In this paper, a fully handheld active micromanipulator known as Micron is evaluated for its feasibility for this delicate operation. An ergonomic handle, a custom tip, and a brace attachment were designed for stapes footplate surgery and tested in a fenestration task through a fixed speculum. Accuracy was measured during simulated surgery in two different scenarios: Micron off (unaided) and Micron on (aided), both with image guidance. Preliminary results show that Micron significantly reduces the mean position error and the mean duration of time spent in specified dangerous zones. PMID:23366167

Correlation and Agreement of Handheld Spirometry with Laboratory Spirometry in Allogeneic Hematopoietic Cell Transplant Recipients.

Science.gov (United States)

Cheng, Guang-Shing; Campbell, Angela P; Xie, Hu; Stednick, Zach; Callais, Cheryl; Leisenring, Wendy M; Englund, Janet A; Chien, Jason W; Boeckh, Michael

2016-05-01

Early detection of subclinical lung function decline may help identify allogeneic hematopoietic cell transplant (HCT) recipients who are at increased risk for late noninfectious pulmonary complications, including bronchiolitis obliterans syndrome. We evaluated the use of handheld spirometry in this population. Allogeneic HCT recipients enrolled in a single-center observational trial performed weekly spirometry with a handheld spirometer for 1 year after transplantation. Participants performed pulmonary function tests in an outpatient laboratory setting at 3 time points: before transplantation, at day 80 after transplantation, and at 1 year after transplantation. Correlation between the 2 methods was assessed by Pearson and Spearman correlations; agreement was assessed using Bland-Altman plots. A total of 437 subjects had evaluable pulmonary function tests. Correlation for forced expiratory volume in 1 second (FEV1) was r = .954 (P spirometry correlated well with laboratory spirometry after allogeneic HCT and may be useful for self-monitoring of patients for early identification of airflow obstruction. Copyright © 2016 American Society for Blood and Marrow Transplantation. All rights reserved.

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

Science.gov (United States)

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

76 FR 22918 - In the Matter of Certain Handheld Electronic Computing Devices, Related Software, and Components...

Science.gov (United States)

2011-04-25

... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-769] In the Matter of Certain Handheld Electronic.... International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on March 21, 2011, under section 337 of the Tariff Act of 1930...

Mean intraocular pressure in hypertensive adults

International Nuclear Information System (INIS)

Irum, S.; Malik, A.M.; Saeed, M.

2015-01-01

To determine the mean Intraocular Pressure (IOP) in already diagnosed adult hypertensive patients with different grades of hypertension. Study Design: Cross-sectional descriptive study. Place and Duration of Study: Combined Military Hospital, Lahore, from March 2012 to Aug 2012. Patients and Methods: A total of 178 already diagnosed hypertensive patients were selected. A detailed history of ocular or systemic diseases was taken. Intraocular pressure was measured with help of Goldmann applanation tonometer. Three consecutive readings of IOP of each eye were taken at 30 minutes interval and mean calculated. Blood pressure was recorded in seated position from right upper arm, by mercury sphygmomanometer. Blood pressure measurements were determined by taking the mean value of three systolic and diastolic readings. Results: The results of intraocular pressure (IOP) between various grades of hypertension were determined. There was an increase in mean IOP with rise in blood pressure. The subjects with grade I hypertension showed a mean IOP of 13.95 ± 3.74 mmHg, while grade II and grade III hypertensive subjects had mean IOPs as 18.10 ± 3.32 and 20.21 ± 2.52 mmHg respectively. Conclusion: A higher value of mean IOP was found with increase in systolic and diastolic blood pressures. (author)

Argon laser trabeculoplasty as primary therapy in open angle glaucoma

International Nuclear Information System (INIS)

Mahar, P.S.; Jamali, K.K.

2008-01-01

To determine the effect of Argon Laser Trabeculoplasty (ALT) as a primary mode of therapy in reducing the intraocular Pressure (IOP) of patients diagnosed with Primary Open Angle Glaucoma (POAG). A total of 35 eyes of 35 patients with the gender distribution of 27 men and 8 women who were newly diagnosed with POAG, were included in this study. Mean age of the patients was 55.2 years with the range of 32 to 76 years. All of them were treated with argon laser trabeculoplasty as a primary mode of therapy. Intra ocular pressure was measured objectively using Goldman applanation tonometer, pre-and-post laser therapy. The pre-laser mean IOP was 27.63 mmHg (range 21-40 mmHg). The post-laser mean IOP measured at 6 months follow up was 15.5 mmHg (range 11 - 33 mmHg) with mean decrease of 12.1 mmHg. The decrease in IOP was seen in 32 eyes (95%) with no change observed in 3 (5%) eyes. The result shows a marked decline in IOP in patients with POAG who underwent ALT as a primary mode of treatment. Further studies with large sample size and longer follow-up will help in making future recommendations. (author)

Ocular disease in the guinea pig (Cavia porcellus): a survey of 1000 animals.

Science.gov (United States)

Williams, David; Sullivan, Ann

2010-09-01

Anecdotal evidence has suggested that guinea pigs have a high prevalence of ocular lesions. Here we undertook a survey of 1000 guinea pigs from populations of animals kept as laboratory animals, breeding show cavies, animals kept as pets and those from rescue and rehoming centers. Each animal was examined to assess for ocular abnormalities. A full ophthalmic examination was performed on each animal with direct and indirect ophthalmoscopy and with slit lamp biomicroscopy. Measurement of tear production using the Schirmer tear test 1 and intraocular pressure using the Tonopen applanation tonometer after topical anesthesia was undertaken in selected animals. Forty-five percent of animals examined had some ocular abnormality. The majority were lens lesions including 17% with cataract and 21% with subclinical lens abnormalities such as nuclear sclerosis. Other abnormalities included conjunctivitis in 4.7% and keratitis in 3.6%. Lipid deposition in conjunctiva was observed in 2.3% of guinea pigs and ciliary body heterotopic bone formation in 0.8% of animals. This study shows a high proportion of eyes with some degree of abnormality in animals otherwise considered healthy. Information on diseases of the guinea pig eye is important given the use of the species as a laboratory rodent and also the number kept as pets and show animals.

Comparative Geometrical Investigations of Hand-Held Scanning Systems

Science.gov (United States)

Kersten, T. P.; Przybilla, H.-J.; Lindstaedt, M.; Tschirschwitz, F.; Misgaiski-Hass, M.

2016-06-01

An increasing number of hand-held scanning systems by different manufacturers are becoming available on the market. However, their geometrical performance is little-known to many users. Therefore the Laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has carried out geometrical accuracy tests with the following systems in co-operation with the Bochum University of Applied Sciences (Laboratory for Photogrammetry) as well as the Humboldt University in Berlin (Institute for Computer Science): DOTProduct DPI-7, Artec Spider, Mantis Vision F5 SR, Kinect v1 + v2, Structure Sensor and Google's Project Tango. In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data were acquired by measurement with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M). The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

Intra-operative ultrasound hand-held strain imaging for the visualization of ablations produced in the liver with a toroidal HIFU transducer: first in vivo results

Energy Technology Data Exchange (ETDEWEB)

Chenot, J; Melodelima, D; N' Djin, W A; Souchon, Remi; Rivoire, M; Chapelon, J Y, E-mail: jeremy.chenot@inserm.f [Inserm, U556, Lyon, F-69003 (France)

2010-06-07

The use of hand-held ultrasound strain imaging for the intra-operative real-time visualization of HIFU (high-intensity focused ultrasound) ablations produced in the liver by a toroidal transducer was investigated. A linear 12 MHz ultrasound imaging probe was used to obtain radiofrequency signals. Using a fast cross-correlation algorithm, strain images were calculated and displayed at 60 frames s{sup -1}, allowing the use of hand-held strain imaging intra-operatively. Fourteen HIFU lesions were produced in four pigs. Intra-operative strain imaging of HIFU ablations in the liver was feasible owing to the high frame rate. The correlation between dimensions measured on gross pathology and dimensions measured on B-mode images and on strain images were R = 0.72 and R = 0.94 respectively. The contrast between ablated and non-ablated tissue was significantly higher (p < 0.05) in the strain images (22 dB) than in the B-mode images (9 dB). Strain images allowed equivalent or improved definition of ablated regions when compared with B-mode images. Real-time intra-operative hand-held strain imaging seems to be a promising complement to conventional B-mode imaging for the guidance of HIFU ablations produced in the liver during an open procedure. These results support that hand-held strain imaging outperforms conventional B-mode ultrasound and could potentially be used for the assessment of thermal therapies.

An Adaptive Geometry Game for Handheld Devices

Directory of Open Access Journals (Sweden)

Harri Ketamo

2003-01-01

Full Text Available The development of adaptive learning systems is only in the very beginning. In fact, the concept of adaptive learning systems range from different user interfaces to behaviour adaptive systems as well as from the place and time independent systems to terminal independent systems. When approaching the concept of adaptive learning materials, we must first have conceptual models of the behaviour of different learners within digital environments.The aim of this study was to develop a geometry learning game that adapts to user’s behaviour. The learners in this study were six years old Finnish pre-school pupils. The adaptive system was very limited and the observed behaviour was defined as very simple. However, the software developed achieves good learning results among the tested pupils. The study shows that the learning effect is very promising with this kind of handheld platform and simple adaptation system. This study gives good visions of what can be achieved with more complex behaviour adaptive systems in the field of eLearning.

Extensional rheometry with a handheld mobile device

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Precise intraoperative location of gastrointestinal bleeding with a hand-held counter. Work in progress

International Nuclear Information System (INIS)

Williamson, M.R.; Boyd, C.M.; McGuire, E.L.

1986-01-01

The nuclear medicine bleeding scan is frequently insufficient to locate sites of bleeding precisely, in spite of its great sensitivity. A small, hand-held Geiger-Mueller counter, placed directly on exposed intestine in the operating room, enables precise location of the probable bleeding site. In three patients, the technique allowed a minimal amount of intestine to be resected, distinguished between large- and small-intestinal hemorrhage, and eliminated other foci as sites of bleeding.A

Intraocular pressure measurements in relation to head position and through soft contact lenses: comparison of three portable instruments.

Science.gov (United States)

Klein, Ainat; Shemesh, Gabi; Loewenstein, Anat; Kurtz, Shimon

2011-01-01

to compare the reproducibility of three portable instruments-the Tono-Pen tonometer (Reichert Ophthalmic Instruments, Depew, NY), the Phosphene tonometer (Bausch & Lomb, Rochester, NY), and the TERT (Through Eyelid Russian Tonometer; Rjazan State Instrument Making, Rjazan, Russia)-in the measurement of intraocular pressure (IOP) with and without soft contact lenses and in different head positions. twenty-six eyes of healthy volunteers were examined by the three instruments while the subjects were sitting, recumbent, and hyperextending their heads, and with and without contact lenses. IOP measurements were compared and the effects of head position and presence of contact lenses on the resultant values were analyzed. the average difference between the recumbent and sitting positions was 3.56, 2.68, and 2.62 mm Hg for the Tono-Pen tonometer, Phosphene tonometer, and TERT, respectively. There was an increase of 5.60, 2.78, and 2.63 mm Hg in hyperextension compared to sitting for the Tono-Pen tonometer, Phosphene tonometer, and TERT, respectively. The difference in the IOP values obtained in the presence and absence of therapeutic contact lens for the three instruments in the three positions was between -1.23 and +1.47 mm Hg. IOP measurements of bedridden patients are only slightly higher than those of sitting patients except for the Tono-Pen tonometer in the hyperextension position. The presence of contact lenses does not affect IOP values obtained by the three evaluated instruments.

Applicability of a Diffuse Reflectance Infrared Fourier Transform handheld spectrometer to perform in situ analyses on Cultural Heritage materials.

Science.gov (United States)

Arrizabalaga, Iker; Gómez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

2014-08-14

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. Copyright © 2014 Elsevier B.V. All rights reserved.

COMPARATIVE GEOMETRICAL INVESTIGATIONS OF HAND-HELD SCANNING SYSTEMS

Directory of Open Access Journals (Sweden)

T. P. Kersten

2016-06-01

Full Text Available An increasing number of hand-held scanning systems by different manufacturers are becoming available on the market. However, their geometrical performance is little-known to many users. Therefore the Laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has carried out geometrical accuracy tests with the following systems in co-operation with the Bochum University of Applied Sciences (Laboratory for Photogrammetry as well as the Humboldt University in Berlin (Institute for Computer Science: DOTProduct DPI-7, Artec Spider, Mantis Vision F5 SR, Kinect v1 + v2, Structure Sensor and Google’s Project Tango. In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data were acquired by measurement with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M. The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

Hand-held optical fuel pin scanner

International Nuclear Information System (INIS)

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

1987-01-01

A portable, hand-held apparatus is described for optically scanning indicia imprinted about a planar end face of an article having an outer wall surface, the apparatus comprising: a supporting frame; light detector means fixed to the frame for digitizing light patterns directed thereto; indexing means on the frame for engaging the planar end face and locating the end face in a preselected focal plane on the frame. The indexing means has an inner wall surface complementary to the article wall surface for disposition thereabout and terminates in an end portion beyond the planar end face. The inner wall surface has a radially inwardly extending shoulder spaced from the end portion and engageable with the planar end face; light means directed onto the preselected focal plane; optical means mounted on the frame about a central axis, the optical means being optically interposed between the indexing means and the light detector means for directing reflected light from the preselected focal plane to the light detector means and including a dove prism centrally aligned along the central axis; and means for selectively rotating the dove prism relative to the frame about the central axis to thereby rotate the image from the focal plane as transmitted to the light detector means

Hip- and knee-strength assessments using a hand-held dynamometer with external belt-fixation are inter-tester reliable

DEFF Research Database (Denmark)

Thorborg, Kristian; Bandholm, Thomas; Hölmich, Per

2013-01-01

PURPOSE: In football, ice-hockey, and track and field, injuries have been predicted, and hip- and knee-strength deficits quantified using hand-held dynamometry (HHD). However, systematic bias exists when testers of different sex and strength perform the measurements. Belt-fixation of the dynamome...

Visual Search and Target Cueing: A Comparison of Head-Mounted Versus Hand-Held Displays on the Allocation of Visual Attention

National Research Council Canada - National Science Library

Yeh, Michelle; Wickens, Christopher D

1998-01-01

We conducted a study to examine the effects of target cueing and conformality with a hand-held or head-mounted display to determine their effects on visual search tasks requiring focused and divided attention...

Handheld and automated ultrasonic spray deposition of conductive PEDOT:PSS films and their application in AC EL devices

NARCIS (Netherlands)

Ely, Fernando; Matsumoto, Agatha; Zoetebier, Bram; Peressinotto, Valdirene S.; Hirata, Marcelo Kioshi; de Sousa, Douglas A.; Maciel, Rubens

2014-01-01

In this contribution we explore the spray deposition technique to achieve smooth films based on the conductive polymer PEDOT:PSS. Two different spray systems were used and compared namely: (a) handheld airbrush and (b) automated ultrasonic spray system. For each system a number of parameters were

Performance Investigation of a Handheld 3d Scanner to Define Good Practices for Small Artefact 3d Modeling

Science.gov (United States)

Lachat, E.; Landes, T.; Grussenmeyer, P.

2017-08-01

Handheld 3D scanners can be used to complete large scale models with the acquisition of occluded areas or small artefacts. This may be of interest for digitization projects in the field of Cultural Heritage, where detailed areas may require a specific treatment. Such sensors present the advantage of being easily portable in the field, and easily usable even without particular knowledge. In this paper, the Freestyle3D handheld scanner launched on the market in 2015 by FARO is investigated. Different experiments are described, covering various topics such as the influence of range or color on the measurements, but also the precision achieved for geometrical primitive digitization. These laboratory experiments are completed by acquisitions performed on engraved and sculpted stone blocks. This practical case study is useful to investigate which acquisition protocol seems to be the more adapted and leads to precise results. The produced point clouds will be compared to photogrammetric surveys for the purpose of their accuracy assessment.

Linear Text vs. Non-Linear Hypertext in Handheld Computers: Effects on Declarative and Structural Knowledge, and Learner Motivation

Science.gov (United States)

Son, Chanhee; Park, Sanghoon; Kim, Minjeong

2011-01-01

This study compared linear text-based and non-linear hypertext-based instruction in a handheld computer regarding effects on two different levels of knowledge (declarative and structural knowledge) and learner motivation. Forty four participants were randomly assigned to one of three experimental conditions: linear text, hierarchical hypertext,…

DNA aptamer beacon assay for C-telopeptide and handheld fluorometer to monitor bone resorption.

Science.gov (United States)

Bruno, John Gordon; Carrillo, Maria P; Phillips, Taylor; Hanson, Douglas; Bohmann, Jonathan A

2011-09-01

A novel DNA aptamer beacon is described for quantification of a 26-amino acid C-telopeptide (CTx) of human type I bone collagen. One aptamer sequence and its reverse complement dominated the aptamer pool (31.6% of sequenced clones). Secondary structures of these aptamers were examined for potential binding pockets. Three-dimensional computer models which analyzed docking topologies and binding energies were in agreement with empirical fluorescence experiments used to select one candidate loop for beacon assay development. All loop structures from the aptamer finalists were end-labeled with TYE 665 and Iowa Black quencher for comparison of beacon fluorescence levels as a function of CTx concentration. The optimal beacon, designated CTx 2R-2h yielded a low ng/ml limit of detection using a commercially available handheld fluorometer. The CTx aptamer beacon bound full-length 26-amino acid CTx peptide, but not a shorter 8-amino acid segment of CTx peptide which is a common target for commercial CTx ELISA kits. The prototype assay was shown to detect CTx peptide from human urine after creatinine and urea were removed by size-exclusion chromatography to prevent nonspecific denaturing of the aptamer beacon. This work demonstrates the potential of aptamer beacons to be utilized for rapid and sensitive bone health monitoring in a handheld or point-of-care format.

Estimating the accuracy of optic nerve sheath diameter measurement using a pocket-sized, handheld ultrasound on a simulation model.

Science.gov (United States)

Johnson, Garrett G R J; Zeiler, Frederick A; Unger, Bertram; Hansen, Gregory; Karakitsos, Dimitrios; Gillman, Lawrence M

2016-12-01

Ultrasound measurement of optic nerve sheath diameter (ONSD) appears to be a promising, rapid, non-invasive bedside tool for identification of elevated intra-cranial pressure. With improvements in ultrasound technology, machines are becoming smaller; however, it is unclear if these ultra-portable handheld units have the resolution to make these measurements precisely. In this study, we estimate the accuracy of ONSD measurement in a pocket-sized ultrasound unit. Utilizing a locally developed, previously validated model of the eye, ONSD was measured by two expert observers, three times with two machines and on five models with different optic nerve sheath sizes. A pocket ultrasound (Vscan, GE Healthcare) and a standard portable ultrasound (M-Turbo, SonoSite) were used to measure the models. Data was analyzed by Bland-Altman plot and intra-class correlation coefficient (ICC). The ICC between raters for the SonoSite was 0.878, and for the Vscan was 0.826. The between-machine agreement ICC was 0.752. Bland-Altman agreement analysis between the two ultrasound methods showed an even spread across the range of sheath sizes, and that the Vscan tended to read on average 0.33 mm higher than the SonoSite for each measurement, with a standard deviation of 0.65 mm. Accurate ONSD measurement may be possible utilizing pocket-sized, handheld ultrasound devices despite their small screen size, lower resolution, and lower probe frequencies. Further study in human subjects is warranted for all newer handheld ultrasound models as they become available on the market.

The use of handheld radiometry for the identification of stratigraphic characteristics of Paraiba Basin units

International Nuclear Information System (INIS)

Souza, Ebenezer Moreno de; Villar, Heldio Pereira; Lima, Ricardo de Andrade; Lima Filho, Mario

2000-01-01

A study on the use of radiometric techniques for the identification of stratigraphic characteristics of Paraiba Basin units was carried out with handheld instrumentation. The area chosen ran from north Pernambuco to south Paraiba. The presence of radioactive material had been previously determined. For this work a portable scintillometer was fixed to the door of a vehicle, on the outside, with the probe directed downwards. Background radiation was measured as 40 cps (counts per second). The scintillometer has an alarm which sounds whenever the measured count rate rises above a pre-established figure, 100 cps in the present case. Monitoring then proceeded manually. In sites where the count rate was much higher than 100 cps, the probe was lowered to the soil surface. Local coordinates were obtained by GPS. Therefore, an isoradioactivity map of the area could be drawn. The comparison between this map and local geological charts showed significant correlation between observed count rates and geologic formations. Low count rates were indicative of the Barreiras formation, whereas the highest rates were obtained for the Gramame formation (with urano-phosphatic lythotypes). It is concluded that handheld radiometry is a useful tool in geological charting, is special in areas where stratigraphic units have been masked by environmental changes and human activities. (author)

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

Science.gov (United States)

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.

Influence of Fine Motor Skill on Accuracy of Measurements Using a Handheld Sliding Caliper at Adolescents Group Aged 19-20

Science.gov (United States)

Brychta, Petr; Hojk, Vladimír; Hrubý, Jiří; Pilc, Jozef

2017-10-01

This innovate ve interdisciplinary study deals with influence of fine motor skill level (finger dexterity) of individual on his measurement results in metrology practice. The main objective of this study was determinate fine motor skill level of individuals using a motor test. Further determinate the potential effect of different fine motor skill levels on accuracy of measuring using a mechanical handheld sliding caliper. Fine motor skill test and metrological test were implemented. Pursuant the results of fine motor skill test were probands divided into 2 groups. The groups are significantly different on accuracy of measurement (p=0,006). Pearson coefficient shows a significant correlation r = - 0.66 between the Purdue Pegboard test and a measurement error. Results confirmed that the fine motor skill of the upper limbs (especially finger coordination) significantly influence accuracy of measurement using a mechanical handheld sliding caliper.

Comparison of low-cost handheld retinal camera and traditional table top retinal camera in the detection of retinal features indicating a risk of cardiovascular disease

Science.gov (United States)

Joshi, V.; Wigdahl, J.; Nemeth, S.; Zamora, G.; Ebrahim, E.; Soliz, P.

2018-02-01

Retinal abnormalities associated with hypertensive retinopathy are useful in assessing the risk of cardiovascular disease, heart failure, and stroke. Assessing these risks as part of primary care can lead to a decrease in the incidence of cardiovascular disease-related deaths. Primary care is a resource limited setting where low cost retinal cameras may bring needed help without compromising care. We compared a low-cost handheld retinal camera to a traditional table top retinal camera on their optical characteristics and performance to detect hypertensive retinopathy. A retrospective dataset of N=40 subjects (28 with hypertensive retinopathy, 12 controls) was used from a clinical study conducted at a primary care clinic in Texas. Non-mydriatic retinal fundus images were acquired using a Pictor Plus hand held camera (Volk Optical Inc.) and a Canon CR1-Mark II tabletop camera (Canon USA) during the same encounter. The images from each camera were graded by a licensed optometrist according to the universally accepted Keith-Wagener-Barker Hypertensive Retinopathy Classification System, three weeks apart to minimize memory bias. The sensitivity of the hand-held camera to detect any level of hypertensive retinopathy was 86% compared to the Canon. Insufficient photographer's skills produced 70% of the false negative cases. The other 30% were due to the handheld camera's insufficient spatial resolution to resolve the vascular changes such as minor A/V nicking and copper wiring, but these were associated with non-referable disease. Physician evaluation of the performance of the handheld camera indicates it is sufficient to provide high risk patients with adequate follow up and management.

Beyond mere information provisioning: a handheld museum guide based on social activities and playful learning

OpenAIRE

SCHROYEN, Jolien; GABRIELS, Kris; TEUNKENS, Daniel; ROBERT, Karel; LUYTEN, Kris; CONINX, Karin

2007-01-01

During a museum visit, social interaction can improve intellectual, social, personal and cultural development. With the advances in technology, the use of personal mobile handheld devices – such as Personal Digital Assistants (PDAs) – that replace the traditional paper guidebooks is becoming a common sight at various heritage sites all over the world. This technology often leads to problems such as isolating visitors from their companions and distracting visitors away from their surroundings....

First demonstration of real-time gamma imaging by using a handheld Compton camera for particle therapy

Energy Technology Data Exchange (ETDEWEB)

Taya, T., E-mail: taka48138@ruri.waseda.jp [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kataoka, J.; Kishimoto, A.; Iwamoto, Y.; Koide, A. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Nishio, T. [Graduate School of Biomedical and Health Science, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-shi, Hiroshima (Japan); Kabuki, S. [School of Medicine, Tokai University, 143 Shimokasuya, Isehara-shi, Kanagawa (Japan); Inaniwa, T. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba (Japan)

2016-09-21

The use of real-time gamma imaging for cancer treatment in particle therapy is expected to improve the accuracy of the treatment beam delivery. In this study, we demonstrated the imaging of gamma rays generated by the nuclear interactions during proton irradiation, using a handheld Compton camera (14 cm×15 cm×16 cm, 2.5 kg) based on scintillation detectors. The angular resolution of this Compton camera is ∼8° at full width at half maximum (FWHM) for a {sup 137}Cs source. We measured the energy spectra of the gamma rays using a LaBr{sub 3}(Ce) scintillator and photomultiplier tube, and using the handheld Compton camera, performed image reconstruction when using a 70 MeV proton beam to irradiate a water, Ca(OH){sub 2}, and polymethyl methacrylate (PMMA) phantom. In the energy spectra of all three phantoms, we found an obvious peak at 511 keV, which was derived from annihilation gamma rays, and in the energy spectrum of the PMMA phantom, we found another peak at 718 keV, which contains some of the prompt gamma rays produced from {sup 10}B. Therefore, we evaluated the peak positions of the projection from the reconstructed images of the PMMA phantom. The differences between the peak positions and the Bragg peak position calculated using simulation are 7 mm±2 mm and 3 mm±8 mm, respectively. Although we could quickly acquire online gamma imaging of both of the energy ranges during proton irradiation, we cannot arrive at a clear conclusion that prompt gamma rays sufficiently trace the Bragg peak from these results because of the uncertainty given by the spatial resolution of the Compton camera. We will develop a high-resolution Compton camera in the near future for further study. - Highlights: • Gamma imaging during proton irradiation by a handheld Compton camera is demonstrated. • We were able to acquire the online gamma-ray images quickly. • We are developing a high resolution Compton camera for range verification.

An integrated portable hand-held analyser for real-time isothermal nucleic acid amplification

International Nuclear Information System (INIS)

Smith, Matthew C.; Steimle, George; Ivanov, Stan; Holly, Mark; Fries, David P.

2007-01-01

A compact hand-held heated fluorometric instrument for performing real-time isothermal nucleic acid amplification and detection is described. The optoelectronic instrument combines a Printed Circuit Board/Micro Electro Mechanical Systems (PCB/MEMS) reaction detection/chamber containing an integrated resistive heater with attached miniature LED light source and photo-detector and a disposable glass waveguide capillary to enable a mini-fluorometer. The fluorometer is fabricated and assembled in planar geometry, rolled into a tubular format and packaged with custom control electronics to form the hand-held reactor. Positive or negative results for each reaction are displayed to the user using an LED interface. Reaction data is stored in FLASH memory for retrieval via an in-built USB connection. Operating on one disposable 3 V lithium battery >12, 60 min reactions can be performed. Maximum dimensions of the system are 150 mm (h) x 48 mm (d) x 40 mm (w), the total instrument weight (with battery) is 140 g. The system produces comparable results to laboratory instrumentation when performing a real-time nucleic acid sequence-based amplification (NASBA) reaction, and also displayed comparable precision, accuracy and resolution to laboratory-based real-time nucleic acid amplification instrumentation. A good linear response (R 2 = 0.948) to fluorescein gradients ranging from 0.5 to 10 μM was also obtained from the instrument indicating that it may be utilized for other fluorometric assays. This instrument enables an inexpensive, compact approach to in-field genetic screening, providing results comparable to laboratory equipment with rapid user feedback as to the status of the reaction

An integrated portable hand-held analyser for real-time isothermal nucleic acid amplification

Energy Technology Data Exchange (ETDEWEB)

Smith, Matthew C. [College of Marine Science, University of South Florida, St Petersburg, FL (United States)], E-mail: msmith@marine.usf.edu; Steimle, George; Ivanov, Stan; Holly, Mark; Fries, David P. [College of Marine Science, University of South Florida, St Petersburg, FL (United States)

2007-08-29

A compact hand-held heated fluorometric instrument for performing real-time isothermal nucleic acid amplification and detection is described. The optoelectronic instrument combines a Printed Circuit Board/Micro Electro Mechanical Systems (PCB/MEMS) reaction detection/chamber containing an integrated resistive heater with attached miniature LED light source and photo-detector and a disposable glass waveguide capillary to enable a mini-fluorometer. The fluorometer is fabricated and assembled in planar geometry, rolled into a tubular format and packaged with custom control electronics to form the hand-held reactor. Positive or negative results for each reaction are displayed to the user using an LED interface. Reaction data is stored in FLASH memory for retrieval via an in-built USB connection. Operating on one disposable 3 V lithium battery >12, 60 min reactions can be performed. Maximum dimensions of the system are 150 mm (h) x 48 mm (d) x 40 mm (w), the total instrument weight (with battery) is 140 g. The system produces comparable results to laboratory instrumentation when performing a real-time nucleic acid sequence-based amplification (NASBA) reaction, and also displayed comparable precision, accuracy and resolution to laboratory-based real-time nucleic acid amplification instrumentation. A good linear response (R{sup 2} = 0.948) to fluorescein gradients ranging from 0.5 to 10 {mu}M was also obtained from the instrument indicating that it may be utilized for other fluorometric assays. This instrument enables an inexpensive, compact approach to in-field genetic screening, providing results comparable to laboratory equipment with rapid user feedback as to the status of the reaction.

Object localization in handheld thermal images for fireground understanding

Science.gov (United States)

Vandecasteele, Florian; Merci, Bart; Jalalvand, Azarakhsh; Verstockt, Steven

2017-05-01

Despite the broad application of the handheld thermal imaging cameras in firefighting, its usage is mostly limited to subjective interpretation by the person carrying the device. As remedies to overcome this limitation, object localization and classification mechanisms could assist the fireground understanding and help with the automated localization, characterization and spatio-temporal (spreading) analysis of the fire. An automated understanding of thermal images can enrich the conventional knowledge-based firefighting techniques by providing the information from the data and sensing-driven approaches. In this work, transfer learning is applied on multi-labeling convolutional neural network architectures for object localization and recognition in monocular visual, infrared and multispectral dynamic images. Furthermore, the possibility of analyzing fire scene images is studied and their current limitations are discussed. Finally, the understanding of the room configuration (i.e., objects location) for indoor localization in reduced visibility environments and the linking with Building Information Models (BIM) are investigated.

The effect of lateral decubitus position on nocturnal intraocular pressure over a habitual 24-hour period in healthy adults.

Science.gov (United States)

Hao, Jie; Zhen, Yi; Wang, Hao; Yang, Diya; Wang, Ningli

2014-01-01

To investigate the effect of lateral decubitus position (LDP) on nocturnal intraocular pressure (IOP) and the effect of LDP on 24-hour habitual IOP pattern in healthy subjects. Intraocular pressure was measured every 2-hours using an Accupen Applanation Tonometer (Accutome, USA). During the diurnal period (7:30 am, 9:30 am, 11:30 am, 1:30 pm, 3:30 pm, 5:30 pm, 7:30 pm, and 9:30 pm), IOP was measured in the sitting position under bright light (500-1000 lux) after the subjects had been seated for 5 min. The nocturnal IOP was measured in the supine position, right LDP, and left LDP, with randomized sequences, under dim light (hour habitual IOP patterns were obtained according to the nocturnal position (supine, right LDP and left LDP) for either eye. Phour period, the effect of LDP on habitual IOP pattern was not statistically significant, although the mean nocturnal IOP and the diurnal-nocturnal IOP change for the right and the left eye in the LDP pattern was slightly higher than that in the sitting-supine pattern. Significant nocturnal IOP differences existed between the dependent eye and the supine, but did not occur consistently for all time points. Over a 24-hour period, the effect of LDP on habitual IOP pattern was not statistically significant in healthy subjects.

Corneal biomechanical changes in diabetes mellitus and their influence on intraocular pressure measurements.

Science.gov (United States)

Sahin, Afsun; Bayer, Atilla; Ozge, Gökhan; Mumcuoğlu, Tarkan

2009-10-01

To investigate possible corneal biomechanical changes in patients with diabetes mellitus and understand the influence of such changes on intraocular pressure measurements. The study group was composed of 120 eyes from 61 healthy control subjects and 81 eyes from 43 diabetic subjects. IOP was measured first with an ocular response analyzer (ORA) and subsequently with a Goldmann applanation tonometer (GAT). Central corneal thickness (CCT) was measured with an ultrasonic pachymeter attached to the ORA. Axial length (AL), anterior chamber depth (ACD), and keratometry readings were acquired with partial coherence laser interferometry during the same visit before all IOP and CCT determinations were made. Corneal hysteresis (CH) was found to be significantly lower in diabetic patients when compared with healthy control subjects (9.51 +/- 1.82 mm Hg vs. 10.41 +/- 1.66 mm Hg, P < 0.0001). There was no significant difference in terms of corneal resistance factor (CRF; P = 0.8). Mean CCT, GAT IOP, Goldmann-correlated IOP (IOPg), and corneal-compensated IOP (IOPcc) were significantly higher in diabetic patients than in healthy control subjects (P = 0.01 for CCT, P < 0.0001 for GAT IOP, IOPg, and IOPcc). Diabetes affects corneal biomechanics and results in lower CH values than those in healthy control subjects, which may cause clinically relevant high IOP measurements independent of CCT.

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

Science.gov (United States)

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.

Towards Robust Self-Calibration for Handheld 3d Line Laser Scanning

Science.gov (United States)

Bleier, M.; Nüchter, A.

2017-11-01

This paper studies self-calibration of a structured light system, which reconstructs 3D information using video from a static consumer camera and a handheld cross line laser projector. Intersections between the individual laser curves and geometric constraints on the relative position of the laser planes are exploited to achieve dense 3D reconstruction. This is possible without any prior knowledge of the movement of the projector. However, inaccurrately extracted laser lines introduce noise in the detected intersection positions and therefore distort the reconstruction result. Furthermore, when scanning objects with specular reflections, such as glossy painted or metalic surfaces, the reflections are often extracted from the camera image as erroneous laser curves. In this paper we investiagte how robust estimates of the parameters of the laser planes can be obtained despite of noisy detections.

Implementation of synthetic aperture imaging on a hand-held device

DEFF Research Database (Denmark)

Hemmsen, Martin Christian; Kjeldsen, Thomas; Larsen, Lee

2014-01-01

-held devices all with different chipsets and a BK Medical UltraView 800 ultrasound scanner emulating a wireless probe. The wireless transmission is benchmarked using an imaging setup consisting of 269 scan lines x 1472 complex samples (1.58 MB pr. frame, 16 frames per second). The measured data throughput...... reached an average of 28.8 MB/s using a LG G2 mobile device, which is more than the required data throughput of 25.3 MB/s. Benchmarking the processing performance for B-mode imaging showed a total processing time of 18.9 ms (53 frames/s), which is less than the acquisition time (62.5 ms).......This paper presents several implementations of Syn- thetic Aperture Sequential Beamforming (SASB) on commer- cially available hand-held devices. The implementations include real-time wireless reception of ultrasound radio frequency sig- nals and GPU processing for B-mode imaging. The proposed...

Comparison of maximal voluntary isometric contraction and hand-held dynamometry in measuring muscle strength of patients with progressive lower motor neuron syndrome

NARCIS (Netherlands)

Visser, J.; Mans, E.; de Visser, M.; van den Berg-Vos, R. M.; Franssen, H.; de Jong, J. M. B. V.; van den Berg, L. H.; Wokke, J. H. J.; de Haan, R. J.

2003-01-01

Context. Maximal voluntary isometric contraction, a method quantitatively assessing muscle strength, has proven to be reliable, accurate and sensitive in amyotrophic lateral sclerosis. Hand-held dynamometry is less expensive and more quickly applicable than maximal voluntary isometric contraction.

The applicability of correction factor for corneal thickness on non-contact tonometer measured intraocular pressure in LASIK treated eyes.

Science.gov (United States)

Jethani, Jitendra; Dave, Paaraj; Jethani, Monica; Desai, Yogesh; Patel, Purvi

2016-01-01

To determine the applicability of central corneal thickness (CCT) based correction factor for non-contact tonometer (NCT) measured intraocular pressure (IOP) readings. A prospective, non-randomized study involved 346 eyes of 173 consecutive patients with age ⩾21 years undergoing laser-assisted in situ keratomileusis (LASIK) for myopia and/or myopic astigmatism. The CCT and IOP were measured before and after the LASIK procedure. The IOP pre and post-LASIK was compared after applying the correction factor for CCT. Patients not completing the 3 month postoperative follow-up were excluded. The median spherical equivalent before undergoing LASIK was -4.25D (inter-quartile range, -3.25D). The mean preoperative CCT was 536.82 ± 33.71 μm which reduced to 477.55 ± 39.3 μm (p < 0.01) post-LASIK. The mean IOP reduced from a preoperative value of 14.6 ± 2.32 mmHg to 10.64 ± 2.45 mmHg postoperatively (p < 0.01). On applying correction for the corneal thickness, the pre and postoperative IOP was 15.14 ± 2.8 mmHg and 15.37 ± 2.65 mmHg (p = 0.06) respectively with a strong positive correlation (r = 0.7, p < 0.01). Three hundred eyes (86.7%) had an absolute difference in IOP of less than 3.0 mmHg post-CCT correction which is within the retest variability of NCT. Only 46 eyes (13.3%) had an absolute difference of more than 3.0 mmHg. The modified Ehler's correction algorithm used in this study can be effectively applied in the normal IOP range in a majority of patients.

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

Science.gov (United States)

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.

Possible Radiation-Induced Damage to the Molecular Structure of Wooden Artifacts Due to Micro-Computed Tomography, Handheld X-Ray Fluorescence, and X-Ray Photoelectron Spectroscopic Techniques

Directory of Open Access Journals (Sweden)

Madalena Kozachuk

2016-05-01

Full Text Available This study was undertaken to ascertain whether radiation produced by X-ray photoelectron spectroscopy (XPS, micro-computed tomography (μCT and/or portable handheld X-ray fluorescence (XRF equipment might damage wood artifacts during analysis. Changes at the molecular level were monitored by Fourier transform infrared (FTIR analysis. No significant changes in FTIR spectra were observed as a result of μCT or handheld XRF analysis. No substantial changes in the collected FTIR spectra were observed when XPS analytical times on the order of minutes were used. However, XPS analysis collected over tens of hours did produce significant changes in the FTIR spectra.

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

Science.gov (United States)

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.

The Pixel Paradox and Transition-Metal Spectroscopy: One of Many Uses of the Handheld Digital Microscope in Chemical Demonstrations

Science.gov (United States)

Vitz, Ed

2010-01-01

A handheld digital microscope (HDM) interfaced to a computer with a presentation projector is used to project an out-of-focus yellow patch on the screen, then the patch is brought into focus to show that, paradoxically, there are red and green but no yellow pixels. Chromaticity diagrams are used to discuss this observation and spectroscopic…

Handheld magnetic probe with permanent magnet and Hall sensor for identifying sentinel lymph nodes in breast cancer patients.

Science.gov (United States)

Sekino, Masaki; Kuwahata, Akihiro; Ookubo, Tetsu; Shiozawa, Mikio; Ohashi, Kaichi; Kaneko, Miki; Saito, Itsuro; Inoue, Yusuke; Ohsaki, Hiroyuki; Takei, Hiroyuki; Kusakabe, Moriaki

2018-01-19

The newly developed radioisotope-free technique based on magnetic nanoparticle detection using a magnetic probe is a promising method for sentinel lymph node biopsy. In this study, a novel handheld magnetic probe with a permanent magnet and magnetic sensor is developed to detect the sentinel lymph nodes in breast cancer patients. An outstanding feature of the probe is the precise positioning of the sensor at the magnetic null point of the magnet, leading to highly sensitive measurements unaffected by the strong ambient magnetic fields of the magnet. Numerical and experimental results show that the longitudinal detection length is approximately 10 mm, for 140 μg of iron. Clinical tests were performed, for the first time, using magnetic and blue dye tracers-without radioisotopes-in breast cancer patients to demonstrate the performance of the probe. The nodes were identified through transcutaneous and ex-vivo measurements, and the iron accumulation in the nodes was quantitatively revealed. These results show that the handheld magnetic probe is useful in sentinel lymph node biopsy and that magnetic techniques are widely being accepted as future standard methods in medical institutions lacking nuclear medicine facilities.

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

Science.gov (United States)

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.

Handheld real-time volumetric 3-D gamma-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Haefner, Andrew, E-mail: ahaefner@lbl.gov [Lawrence Berkeley National Lab – Applied Nuclear Physics, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Barnowski, Ross [Department of Nuclear Engineering, UC Berkeley, 4155 Etcheverry Hall, MC 1730, Berkeley, CA 94720 (United States); Luke, Paul; Amman, Mark [Lawrence Berkeley National Lab – Applied Nuclear Physics, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Vetter, Kai [Department of Nuclear Engineering, UC Berkeley, 4155 Etcheverry Hall, MC 1730, Berkeley, CA 94720 (United States); Lawrence Berkeley National Lab – Applied Nuclear Physics, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

2017-06-11

This paper presents the concept of real-time fusion of gamma-ray imaging and visual scene data for a hand-held mobile Compton imaging system in 3-D. The ability to obtain and integrate both gamma-ray and scene data from a mobile platform enables improved capabilities in the localization and mapping of radioactive materials. This not only enhances the ability to localize these materials, but it also provides important contextual information of the scene which once acquired can be reviewed and further analyzed subsequently. To demonstrate these concepts, the high-efficiency multimode imager (HEMI) is used in a hand-portable implementation in combination with a Microsoft Kinect sensor. This sensor, in conjunction with open-source software, provides the ability to create a 3-D model of the scene and to track the position and orientation of HEMI in real-time. By combining the gamma-ray data and visual data, accurate 3-D maps of gamma-ray sources are produced in real-time. This approach is extended to map the location of radioactive materials within objects with unknown geometry.

Portable Hand-Held Electrochemical Sensor for the Transuranics

Energy Technology Data Exchange (ETDEWEB)

Dale D. Russell, William B. Knowlton, Ph.D.; Russel Hertzog, Ph.D

2005-11-25

sensitive detector for uranium. Millimeter scale electrodes, operated by a hand-held instrument assembled in this lab and operated in the voltammetric mode, were transported to the DOE-Nevada test site (Las Vegas, NV) where field detection and quantitation of plutonium, uranium, and a mixture of these two elements was also demonstrated. Several probe designs were prepared, built and tested including probes with movable protective windows. A miniature, battery powered potentiostat was designed, built and demonstrated for use in a hand-held field portable instrument. This work was performed largely by undergraduates who gained valuable research experience, and many of them have continued on to graduate schools. In addition, they all gained exposure to and appreciation for national security research, in particular non-proliferation research. Four graduate students participated and one earned the MS degree on this project.

Injection-depth-locking axial motion guided handheld micro-injector using CP-SSOCT.

Science.gov (United States)

Cheon, Gyeong Woo; Huang, Yong; Kwag, Hye Rin; Kim, Ki-Young; Taylor, Russell H; Gehlbach, Peter L; Kang, Jin U

2014-01-01

This paper presents a handheld micro-injector system using common-path swept source optical coherence tomography (CP-SSOCT) as a distal sensor with highly accurate injection-depth-locking. To achieve real-time, highly precise, and intuitive freehand control, the system used graphics processing unit (GPU) to process the oversampled OCT signal with high throughput and a smart customized motion monitoring control algorithm. A performance evaluation was conducted with 60-insertions and fluorescein dye injection tests to show how accurately the system can guide the needle and lock to the target depth. The evaluation tests show our system can guide the injection needle into the desired depth with 4.12 um average deviation error while injecting 50 nl of fluorescein dye.

Standard echocardiography versus handheld echocardiography for the detection of subclinical rheumatic heart disease: protocol for a systematic review.

Science.gov (United States)

Telford, Lisa H; Abdullahi, Leila H; Ochodo, Eleanor A; Zühlke, Liesl J; Engel, Mark E

2018-02-10

Rheumatic heart disease (RHD) is a preventable and treatable chronic condition which persists in many developing countries largely affecting impoverished populations. Handheld echocardiography presents an opportunity to address the need for more cost-effective methods of diagnosing RHD in developing countries, where the disease continues to carry high rates of morbidity and mortality. Preliminary studies have demonstrated moderate sensitivity as well as high specificity and diagnostic odds for detecting RHD in asymptomatic patients. We describe a protocol for a systematic review on the diagnostic performance of handheld echocardiography compared to standard echocardiography using the 2012 World Heart Federation criteria for diagnosing subclinical RHD. Electronic databases including PubMed, Scopus, Web of Science and EBSCOhost as well as reference lists and citations of relevant articles will be searched from 2012 to date using a predefined strategy incorporating a combination of Medical Subject Heading terms and keywords. The methodological validity and quality of studies deemed eligible for inclusion will be assessed against review specific Quality Assessment of Diagnostic Accuracy Studies 2 criteria and information on metrics of diagnostic accuracy and demographics extracted. Forest plots of sensitivity and specificity as well as scatter plots in receiver operating characteristic (ROC) space will be used to investigate heterogeneity. If possible, a meta-analysis will be conducted to produce summary results of sensitivity and specificity using the Hierarchical Summary ROC method. In addition, a sensitivity analysis will be conducted to investigate the effect of studies with a high risk of bias. Ethics approval is not required for this systematic review of previously published literature. The planned review will provide a summary of the diagnostic accuracy of handheld echocardiography. Results may feed into evidence-based guidelines and should the findings of this

User-friendly tools on handheld devices for observer performance study

Science.gov (United States)

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.

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.

Science.gov (United States)

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.

Analysis of stress-strain state of a human eye by the method of elastotonometry after the surgical correction of hyperopia

Science.gov (United States)

Bauer, S. M.; Venatovskaya, L. A.

2018-05-01

The mathematical model of measuring of the intraocular pressure (IOP) by Maklakoff tonometer in the software package ANSYS, Inc. is presented. The dependence of the tonometric pressure on the weight of the tonometer before and after LASIK and Femto LASIK surgical corrections of hyperopia is analized. Cornea-scleral eye shell is modeled as two thin transversely isotropic joint spherical shells with different radii of curvature and biomechanical properties. To analyze the biomechanical state of the corneoscleral shell of the eye after the surgery the elastotonometry method is used. Firstly sequential measurements of intraocular pressure by Maklakoff tonometers weighting 5; 7.5; 10 and 15 g is carried out, then the dependence curve of tonometric IOP vs. tonometer weight is plotted and analyzed. The results of the calculations are compared with the clinical data.

Poor correlation between intracranial pressure and intraocular pressure by hand-held tonometry

Directory of Open Access Journals (Sweden)

Golan S

2013-06-01

Full Text Available Shani Golan,1 Shimon Kurtz,1 Daphna Mezad-Koursh,1 Michael Waisbourd,1 Anat Kesler,1 Pinchas Halpern2 1Departments of Ophthalmology, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; 2Emergency Medicine, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Purpose: The aim of this study is to provide data on the controversial issue of whether handheld measurements of intraocular pressure (IOP are capable of accurately predicting elevated intracranial pressure (ICP in patients undergoing lumbar puncture (LP. Methods: All patients over the age of 18 years who underwent an LP in the emergency or neurological departments at the Tel Aviv Medical center for any reason between October 2007 and July 2010 were eligible to participate in this prospective observational pilot study. IOP was measured with the Tono-Pen XL while patients were in the supine position before undergoing LP. ICP was measured in the lateral recumbent position. ICP and bilateral IOP were measured, and the mean and maximum values of IOP were calculated. The association between ICP and each one of the four IOP measures was evaluated by the Pearson correlation coefficient. Results: Twenty-four patients (mean age 37.8 ± 15.8 years, ten males and 14 females were enrolled. The reasons for their requiring an LP were headache (19/24 patients, evaluation for hemiparesis (2/24, cognitive deterioration (1/24, and seizures (2/24. Nine had elevated mean opening pressure (>20 cm H2O, six had an elevated mean IOP (>20 mmHg, and four of these six also had an elevated opening pressure. There was no significant correlation between the ICP measurements and any of the IOP measurements. Conclusion: Handheld ocular tonometry has poor sensitivity and specificity for the prediction of increased ICP and is not an effective tool for screening for ICP in the ED or in the

Compact printed two dipole array antenna with a high front-back ratio for ultra-high-frequency radio-frequency identification handheld reader applications

DEFF Research Database (Denmark)

Liu, Qi; Zhang, Shuai; He, Sailing

2015-01-01

A printed two-dipole array antenna with a high front-back ratio is proposed for ultra-high-frequency (UHF) radio-frequency identification handheld readers. The proposed antenna is a parasitic dual-element array with the ends of both elements folded back towards each other for additional coupling....

A hand-held sensor for analyses of local distributions of magnetic fields and losses

CERN Document Server

Krismanic, G; Baumgartinger, N

2000-01-01

The paper describes a novel sensor for non-destructive analyses of local field and loss distributions in laminated soft magnetic cores, such as transformer cores. It was designed for rapid information on comparative local degrees of inhomogeneity, e.g., for the estimation of local building factors. Similar to a magnifying glass with handle, the compact hand-held sensor contains extremely sharp needle electrodes for the detection of the induction vector B as well as double-field coils for the vector H. Losses P are derived from the Poynting law. Applied to inner -- or also outer -- core regions, the sensor yields instantaneous computer displays of local H, B, and P.

Detection of cadmium sulphide nanoparticles by using screen-printed electrodes and a handheld device

International Nuclear Information System (INIS)

Merkoci, Arben; Marcolino-Junior, Luiz Humberto; MarIn, Sergio; Fatibello-Filho, Orlando; Alegret, Salvador

2007-01-01

A simple method based on screen-printed electrodes and a handheld potentiostatic device is reported for the detection of water soluble CdS quantum dots modified with glutathione. The detection method is based on the stripping of electrochemically reduced cadmium at pH 7.0 by using square wave voltammetry. Various parameters that affect the sensitivity of the method are optimized. QD suspension volumes of 20 μl and a number of around 2 x 10 11 CdS quantum dots have been able to be detected. The proposed method should be of special interest for bioanalytical assays, where CdS quantum dots can be used as electrochemical tracers

Reliability of measuring hip abductor strength following total knee arthroplasty using a hand-held dynamometer.

Science.gov (United States)

Schache, Margaret B; McClelland, Jodie A; Webster, Kate E

2016-01-01

To investigate the test-retest reliability of measuring hip abductor strength in patients with total knee arthroplasty (TKA) using a hand-held dynamometer (HHD) with two different types of resistance: belt and manual resistance. Test-retest reliability of 30 subjects (17 female, 13 male, 71.9 ± 7.4 years old), 9.2 ± 2.7 days post TKA was measured using belt and therapist resistance. Retest reliability was calculated with intra-class coefficients (ICC3,1) and 95% confidence intervals (CI) for both the group average and the individual scores. A paired t-test assessed whether a difference existed between the belt and therapist methods of resistance. ICCs were 0.82 and 0.80 for the belt and therapist resisted methods, respectively. Hip abductor strength increases of 8 N (14%) for belt resisted and 14 N (17%) for therapist resisted measurements of the group average exceeded the 95% CI and may represent real change. For individuals, hip abductor strength increases of 33 N (72%) (belt resisted) and 57 N (79%) (therapist resisted) could be interpreted as real change. Hip abductor strength can be reliably measured using HHD in the clinical setting with the described protocol. Belt resistance demonstrated slightly higher test-retest reliability. Reliable measurement of hip abductor muscle strength in patients with TKA is important to ensure deficiencies are addressed in rehabilitation programs and function is maximized. Hip abductor strength can be reliably measured with a hand-held dynamometer in the clinical setting using manual or belt resistance.

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

Science.gov (United States)

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.

Potential air contamination during CO2 angiography using a hand-held syringe: theoretical considerations and gas chromatography.

Science.gov (United States)

Cho, David R; Cho, Kyung J; Hawkins, Irvin F

2006-01-01

To assess air contamination in the hand-held syringes currently used for CO2 delivery and to determine whether there is an association between their position and the rate of air contamination. Assessment of air contamination in the syringe (20 ml) included theoretical modeling, mathematical calculation, and gas chromatography (GC). The model was used with Fick's first law to calculate the diffusion of CO2 and the amount of air contamination. For GC studies, the syringes were placed in the upright, horizontal, and inverted positions and gas samples were obtained after 5, 10, 20, 30, and 60 min. All trials with each position for each sampling time were performed five times. The amounts of air contamination with time calculated mathematically were 5-10% less than those of GC. With the diffusivity of air-CO2 at 0.1599 cm2/sec (9.594 cm2/min), air contamination was calculated to be 60% at 60 min. With GC air contamination was 13% at 5 min, 31% at 20 min, 43% at 30 min, and 68% at 60 min. There was no difference in air contamination between the different syringe positions. Air contamination occurs in hand-held syringes filled with CO2 when they are open to the ambient air. The amounts of air contamination over time are similar among syringes placed in the upright, horizontal, and inverted positions.

Resonance frequency of fluid-filled and prestressed spherical shell-A model of the human eyeball.

Science.gov (United States)

Shih, Po-Jen; Guo, Yi-Ren

2016-04-01

An acoustic tonometer that measures shifts in resonance frequencies associated with intraocular pressure (IOP) could provide an opportunity for a type of tonometer that can be operated at home or worn by patients. However, there is insufficient theoretical background, especially with respect to the uncertainty in operating frequency ranges and the unknown relationships between IOPs and resonance frequencies. The purpose of this paper is to develop a frequency function for application in an acoustic tonometer. A linear wave theory is used to derive an explicit frequency function, consisting of an IOP and seven other physiological parameters. In addition, impulse response experiments are performed to measure the natural frequencies of porcine eyes to validate the provided function. From a real-time detection perspective, explicitly providing a frequency function can be the best way to set up an acoustic tonometer. The theory shows that the resonance oscillation of the eyeball is mainly dominated by liquid inside the eyeball. The experimental validation demonstrates the good prediction of IOPs and resonance frequencies. The proposed explicit frequency function supports further modal analysis not only of the dynamics of eyeballs, but also of the natural frequencies, for further development of the acoustic tonometer.

Science education with handheld devices: A comparison of Nintendo WiiMote and iPod touch for kinematics learning

OpenAIRE

Hochberg, K.; Kuhn, J.; Müller, A.

2016-01-01

Experiential science learning based on the in-built sensors of handheld devices such as smartphones, tablet computer and game consoles has seen quite a strong development in recent years. In particular, such devices with internal acceleration sensors offer an innovative approach to kinematics learning in classroom physics, a notoriously difficult topic for pupils. In view of research and teaching in this domain, the practical advantages and disadvantages of two such devices, the Nintendo WiiM...

Interpreting Mobile and Handheld Air Sensor Readings in Relation to Air Quality Standards and Health Effect Reference Values: Tackling the Challenges

Directory of Open Access Journals (Sweden)

George M. Woodall

2017-09-01

Full Text Available The US Environmental Protection Agency (EPA and other federal agencies face a number of challenges in interpreting and reconciling short-duration (seconds to minutes readings from mobile and handheld air sensors with the longer duration averages (hours to days associated with the National Ambient Air Quality Standards (NAAQS for the criteria pollutants-particulate matter (PM, ozone, carbon monoxide, lead, nitrogen oxides, and sulfur oxides. Similar issues are equally relevant to the hazardous air pollutants (HAPs where chemical-specific health effect reference values are the best indicators of exposure limits; values which are often based on a lifetime of continuous exposure. A multi-agency, staff-level Air Sensors Health Group (ASHG was convened in 2013. ASHG represents a multi-institutional collaboration of Federal agencies devoted to discovery and discussion of sensor technologies, interpretation of sensor data, defining the state of sensor-related science across each institution, and provides consultation on how sensors might effectively be used to meet a wide range of research and decision support needs. ASHG focuses on several fronts: improving the understanding of what hand-held sensor technologies may be able to deliver; communicating what hand-held sensor readings can provide to a number of audiences; the challenges of how to integrate data generated by multiple entities using new and unproven technologies; and defining best practices in communicating health-related messages to various audiences. This review summarizes the challenges, successes, and promising tools of those initial ASHG efforts and Federal agency progress on crafting similar products for use with other NAAQS pollutants and the HAPs. NOTE: The opinions expressed are those of the authors and do not necessary represent the opinions of their Federal Agencies or the US Government. Mention of product names does not constitute endorsement.

Dynamic contour tonometry vs. non-contact tonometry and their relation with corneal thickness

OpenAIRE

Briceño, Adriana; Mas, David; Domenech, Begoña

2016-01-01

The purpose of this study is to evaluate the concordance between intraocular pressure (IOP) values obtained with a dynamic contour tonometer (DCT) and a non-contact tonometer (NCT) in healthy patients and to investigate the effect of central corneal thickness (CCT) on IOP readings for each of the two measuring systems. The mean IOP yielded by DCT, NCT and corrected non-contact tonometer (CNCT) was 17.1 mmHg, 15.5 mmHg and 12.2 mmHg, respectively. The average CCT was 563.6 μm and the ocular pu...

WWC Review of the Report "Conceptualizing Astronomical Scale: Virtual Simulations on Handheld Tablet Computers Reverse Misconceptions." What Works Clearinghouse Single Study Review

Science.gov (United States)

What Works Clearinghouse, 2014

2014-01-01

The 2014 study, "Conceptualizing Astronomical Scale: Virtual Simulations on Handheld Tablet Computers Reverse Misconceptions," examined the effects of using the true-to-scale (TTS) display mode versus the orrery display mode in the iPad's Solar Walk software application on students' knowledge of the Earth's place in the solar system. The…

Clinical effectiveness of the Respimat® inhaler device in managing chronic obstructive pulmonary disease: evidence when compared with other handheld inhaler devices

Directory of Open Access Journals (Sweden)

et al

2011-02-01

Full Text Available Felix SF Ram1, Celso R Carvallho2, John White31School of Health and Social Services, Massey University, Auckland, New Zealand; 2Department of Physical Therapy, School of Medicine, University of São Paulo, Brazil; 3York Hospitals NHS Foundation Trust, York Hospital, York, UKObjectives: Medication for the management of chronic obstructive pulmonary disease (COPD may be delivered by a number of different inhaler devices. This study was undertaken to determine the clinical effectiveness of the Respimat® handheld inhaler device compared with other handheld inhaler devices for the delivery of medication in stable COPD.Methodology: A systematic review of high-quality randomized controlled clinical trials comparing Respimat with other inhaler devices using the same medication was performed. Studies were searched for in the Cochrane Central Register of Controlled Trials as well as other relevant electronic databases. Manufacturers of inhaled COPD medication were also contacted for potential trials.Results: Seven studies of high methodological quality with 3813 participants were included in the review. Three trials used Handihaler® as the comparator inhaler, three used a chlorofluorocarbon metered-dose inhaler (CFC-MDI, and one trial used a hydroflouroalkane (HFA-MDI. When Respimat was compared with Handihaler, the following reported outcomes were not significantly different: trough forced expiratory volume in 1 second (FEV1 (weighted mean difference [WMD] 0.01 L; P = 0.14, trough forced vital capacity (FVC (WMD 0.001 L: P = 0.88, peak FEV1 (WMD 0.01 L: P = 0.08, peak FVC (WMD 0.01 L: P = 0.55, morning peak expiratory flow rate (PEFR (WMD 5.06 L/min: P = 0.08, and evening PEFR (WMD 4.39 L/min: P = 0.15. Furthermore, there were no differences when Respimat was compared with Handihaler for risk of exacerbations (relative risk [RR] 0.94: P = 0.81, dry mouth (RR 1.57: P = 0.34, or nasopharyngitis (RR 1.42: P = 0.22. For Respimat compared with CFC-MDI, the

Photoacoustic cystography using handheld dual modal clinical ultrasound photoacoustic imaging system

Science.gov (United States)

Sivasubramanian, Kathyayini; Periyasamy, Vijitha; Austria, Dienzo Rhonnie; Pramanik, Manojit

2018-02-01

Vesicoureteral reflux is the abnormal flow of urine from your bladder back up the tubes (ureters) that connect your kidneys to your bladder. Normally, urine flows only down from your kidneys to your bladder. Vesicoureteral reflux is usually diagnosed in infants and children. The disorder increases the risk of urinary tract infections, which, if left untreated, can lead to kidney damage. X-Ray cystography is used currently to diagnose this condition which uses ionising radiation, making it harmful for patients. In this work we demonstrate the feasibility of imaging the urinary bladder using a handheld clinical ultrasound and photoacoustic dual modal imaging system in small animals (rats). Additionally, we demonstrate imaging vesicoureteral reflux using bladder mimicking phantoms. Urinary bladder imaging is done with the help of contrast agents like black ink and gold nanoparticles which have high optical absorption at 1064 nm. Imaging up to 2 cm was demonstrated with this system. Imaging was done at a framerate of 5 frames per second.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Prevalence and Determinants of Glaucoma in Citizens of Qatar Aged 40 Years or Older: A Community-Based Survey

Science.gov (United States)

Al-Mansouri, Fatma A.; Kanaan, Aida; Gamra, Hamad; Khandekar, Rajiv; Hashim, Shakeel P.; Al Qahtani, Omar; Ahmed, Mohd. Farouk

2011-01-01

Background: We present the prevalence and determinants of glaucoma among subjects 40 years of age and older in Qatar. Materials and Methods: This community-based survey was held in 2009 at 49 randomly selected clusters. Demographic details and history of glaucoma was collected by the nurses. Ophthalmologists evaluated the optic disc and retina using a digital camera housed in a mobile van. Visual field was tested with an automated perimeter, the intraocular pressure with an applanation tonometer and the angle of the anterior chamber by gonioscopy. A panel of glaucoma experts diagnosed subjects with glaucoma. Results: This survey enrolled 3,149 (97.3%) participants. The age- and sex-adjusted prevalence of glaucoma in the population aged 40 years and older was 1.73% (95% confidence intervals [CI] 1.69-1.77). Accordingly, 5,641 individuals in this age group in Qatar would have glaucoma. Chronological age of 60 years and older (Odds ratio [OR] 11.1) and the presence of myopia (OR 1.78) were predictors of glaucoma. Open-angle glaucoma was diagnosed in 44 (65.7%) individuals with glaucoma. In nine (13.4%) and 15 (20.9%) subjects, angle closure glaucoma and other (post-traumatic, pseudoexfoliation) glaucoma were present. Bilateral blindness (vision glaucoma, respectively. Glaucoma was treated in 36 (54%) subjects. Conclusions: The prevalence of glaucoma among citizens of Qatar aged 40 years and older was 1.71%. Glaucoma was associated with the age of 60 years and older and the presence of myopia. PMID:21731325

Direction-Sensitive Hand-Held Gamma-Ray Spectrometer

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, S.

2012-10-04

A novel, light-weight, hand-held gamma-ray detector with directional sensitivity is being designed. The detector uses a set of multiple rings around two cylindrical surfaces, which provides precise location of two interaction points on two concentric cylindrical planes, wherefrom the source location can be traced back by back projection and/or Compton imaging technique. The detectors are 2.0 × 2.0 mm europium-doped strontium iodide (SrI2:Eu2+) crystals, whose light output has been measured to exceed 120,000 photons/MeV, making it one of the brightest scintillators in existence. The crystal’s energy resolution, less than 3% at 662 keV, is also excellent, and the response is highly linear over a wide range of gamma-ray energies. The emission of SrI2:Eu2+ is well matched to both photo-multiplier tubes and blue-enhanced silicon photodiodes. The solid-state photomultipliers used in this design (each 2.0 × 2.0 mm) are arrays of active pixel sensors (avalanche photodiodes driven beyond their breakdown voltage in reverse bias); each pixel acts as a binary photon detector, and their summed output is an analog representation of the total photon energy, while the individual pixel accurately defines the point of interaction. A simple back-projection algorithm involving cone-surface mapping is being modeled. The back projection for an event cone is a conical surface defining the possible location of the source. The cone axis is the straight line passing through the first and second interaction points.

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

Science.gov (United States)

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.

Potential Air Contamination During CO2 Angiography Using a Hand-Held Syringe: Theoretical Considerations and Gas Chromatography

International Nuclear Information System (INIS)

Cho, David R.; Cho, Kyung J.; Hawkins, Irvin F.

2006-01-01

Purpose. To assess air contamination in the hand-held syringes currently used for CO 2 delivery and to determine whether there is an association between their position and the rate of air contamination. Methods. Assessment of air contamination in the syringe (20 ml) included theoretical modeling, mathematical calculation, and gas chromatography (GC). The model was used with Fick's first law to calculate the diffusion of CO 2 and the amount of air contamination. For GC studies, the syringes were placed in the upright, horizontal, and inverted positions and gas samples were obtained after 5, 10, 20, 30, and 60 min. All trials with each position for each sampling time were performed five times. Results. The amounts of air contamination with time calculated mathematically were 5-10% less than those of GC. With the diffusivity of air-CO 2 at 0.1599 cm 2 /sec (9.594 cm 2 /min), air contamination was calculated to be 60% at 60 min. With GC air contamination was 13% at 5 min, 31% at 20 min, 43% at 30 min, and 68% at 60 min. There was no difference in air contamination between the different syringe positions. Conclusion. Air contamination occurs in hand-held syringes filled with CO 2 when they are open to the ambient air. The amounts of air contamination over time are similar among syringes placed in the upright, horizontal, and inverted positions

Development and performance of a hand-held CZT detector for in-situ measurements at the emergency response

Energy Technology Data Exchange (ETDEWEB)

Ji, Young Yong; Chung, Kun Ho; Kim, Chang Jong; Lee, Wan No; Choi, Geun Sik; Kang, Mun Ja [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yoon, Jin [SI Detection Co. Ltd, Daejeon (Korea, Republic of)

2016-06-15

A hand-held detector for an emergency response was developed for nuclide identification and to estimate the information of the ambient dose rate in the scene of an accident as well as the radioactivity of the contaminants. To achieve this, the most suitable sensor was first selected as a cadmium zinc telluride (CZT) semiconductor and the signal processing unit from a sensor and the signal discrimination and storage unit were successfully manufactured on a printed circuit board. The performance of the developed signal processing unit was then evaluated to have an energy resolution of about 14 keV at 662 keV. The system control unit was also designed to operate the CZT detector, monitor the detector, battery, and interface status, and check and transmit the measured results of the ambient dose rate and radioactivity. In addition, a collimator, which can control the inner radius, and the airborne dust sampler, which consists of an air filter and charcoal filter, were developed and mounted to the developed CZT detector for the quick and efficient response of a nuclear accident. The hand-held CZT detector was developed to make the in-situ gamma-ray spectrometry and its performance was checked to have a good energy resolution. In addition, the collimator and the airborne dust sampler were developed and mounted to the developed CZT detector for a quick and efficient response to a nuclear accident.

Clinical assessment of hip strength using a hand-held dynamometer is reliable

DEFF Research Database (Denmark)

Thorborg, K; Petersen, J; Magnusson, S P

2010-01-01

rotation (ER), internal rotation (IR), flexion (FLEX) and extension (EXT) using a hand-held dynamometer. Nine subjects (five males, four females), physically active for at least 2.5 h a week, were included. Twelve standardized isometric strength tests were performed twice with a 1-week interval in between......Hip strength assessment plays an important role in the clinical examination of the hip and groin region. The primary aim of this study was to examine the absolute test-retest measurement variation concerning standardized strength assessments of hip abduction (ABD), adduction (ADD), external...... by the same examiner. The test order was randomized to avoid systematic bias. Measurement variation between sessions was 3-12%. When the maximum value of four measurements was used, test-retest measurement variation was below 10% in 11 of the 12 individual hip strength tests and below 5% in five of the 12...

Inter-Tester Reliability and Precision of Manual Muscle Testing and Hand-Held Dynamometry in Lower Limb Muscles of Children with Spina Bifida

Science.gov (United States)

Mahony, Kate; Hunt, Adrienne; Daley, Deborah; Sims, Susan; Adams, Roger

2009-01-01

Reliability and measurement precision of manual muscle testing (MMT) and hand-held dynamometry (HHD) were compared for children with spina bifida. Strength measures were obtained of the hip flexors, hip abductors, and knee extensors of 20 children (10 males, 10 females; mean age 9 years 10 months; range: 5 to 15 years) by two experienced physical…

Attentionally splitting the mass distribution of hand-held rods.

Science.gov (United States)

Burton, G; Turvey, M T

1991-08-01

Two experiments on the length-perception capabilities of effortful or dynamic touch differed only in terms of what the subject intended to perceive, while experimental conditions and apparatus were held constant. In each trial, a visually occluded rod was held as still as possible by the subject at an intermediate position. For two thirds of the trials, a weight was attached to the rod above or below the hand. In Experiment 1, in which the subject's task was to perceive the distance reachable with the portion of the rod forward of the hand, perceived extent was a function of the first moment of the mass distribution associated with the forward portion of the rod, and indifferent to the first moment of the entire rod. In Experiment 2, in which the task was to perceive the distance reachable with the entire rod if it was held at an end, the pattern of results was reversed. These results indicate the capability of selective sensitivity to different aspects of a hand-held object's mass distribution, without the possibility of differential exploration specific to these two tasks. Results are discussed in relation to possible roles of differential information, intention, and self-organization in the explanations of selective perceptual abilities.

Mobile Testing of Cognitive Function : A tool for assessment of cognitive abilities in an everyday environment using a handheld device

OpenAIRE

Fouchenette, Kim

2011-01-01

The unit of Cognitive Developmental Neuroscience at Karolinska Institutet have developed a method for measuring cognitive performance with handheld devices, which resulted in a mobile application for the iPod Touch. The application was previously used in a clinical trial with individuals suffering from chronic stress disorder, but had to be further developed. The application, which consisted of cognitive tests and questionnaires, required improvements that could be divided into three parts: (...

Intrarater reliabilities of shoulder joint horizontal adductor muscle strength measurements using a handheld dynamometer for geriatric and stroke patients

OpenAIRE

Hirano, Masahiro; Katoh, Munenori; Kawaguchi, Saori; Uemura, Tomomi

2016-01-01

[Purpose] This study aimed to verify the appropriate number of measurements and the intrarater reliabilities of shoulder joint horizontal adductor muscle strength measurements using a handheld dynamometer (HHD) for geriatric and stroke patients. [Subjects and Methods] The subjects were 40 inpatients, who were divided into two groups: 20 stroke patients in the stroke group (SG), and 20 geriatric patients in the no-stroke group (N-SG). Measurements were performed three times using an HHD with a...

Assessment of isometric muscle strength and rate of torque development with hand-held dynamometry: Test-retest reliability and relationship with gait velocity after stroke.

Science.gov (United States)

Mentiplay, Benjamin F; Tan, Dawn; Williams, Gavin; Adair, Brooke; Pua, Yong-Hao; Bower, Kelly J; Clark, Ross A

2018-04-27

Isometric rate of torque development examines how quickly force can be exerted and may resemble everyday task demands more closely than isometric strength. Rate of torque development may provide further insight into the relationship between muscle function and gait following stroke. Aims of this study were to examine the test-retest reliability of hand-held dynamometry to measure isometric rate of torque development following stroke, to examine associations between strength and rate of torque development, and to compare the relationships of strength and rate of torque development to gait velocity. Sixty-three post-stroke adults participated (60 years, 34 male). Gait velocity was assessed using the fast-paced 10 m walk test. Isometric strength and rate of torque development of seven lower-limb muscle groups were assessed with hand-held dynamometry. Intraclass correlation coefficients were calculated for reliability and Spearman's rho correlations were calculated for associations. Regression analyses using partial F-tests were used to compare strength and rate of torque development in their relationship with gait velocity. Good to excellent reliability was shown for strength and rate of torque development (0.82-0.97). Strong associations were found between strength and rate of torque development (0.71-0.94). Despite high correlations between strength and rate of torque development, rate of torque development failed to provide significant value to regression models that already contained strength. Assessment of isometric rate of torque development with hand-held dynamometry is reliable following stroke, however isometric strength demonstrated greater relationships with gait velocity. Further research should examine the relationship between dynamic measures of muscle strength/torque and gait after stroke. Copyright © 2018 Elsevier Ltd. All rights reserved.

A novel fully integrated handheld gamma camera

International Nuclear Information System (INIS)

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

2016-01-01

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.

A novel fully integrated handheld gamma camera

Energy Technology Data Exchange (ETDEWEB)

Massari, R.; Ucci, A.; Campisi, C. [Biostructure and Bioimaging Institute (IBB), National Research Council of Italy (CNR), Rome (Italy); Scopinaro, F. [University of Rome “La Sapienza”, S. Andrea Hospital, Rome (Italy); Soluri, A., E-mail: alessandro.soluri@ibb.cnr.it [Biostructure and Bioimaging Institute (IBB), National Research Council of Italy (CNR), Rome (Italy)

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.

Quantitative evaluation of a handheld light microscope for field diagnosis of soil-transmitted helminth infection.

Science.gov (United States)

Bogoch, Isaac I; Andrews, Jason R; Speich, Benjamin; Ame, Shaali M; Ali, Said M; Stothard, J Russell; Utzinger, Jürg; Keiser, Jennifer

2014-12-01

We evaluated the Newton Nm1, a commercially available handheld light microscope and compared it with conventional light microscopy for the diagnosis of soil-transmitted helminth infections. A total of 91 Kato-Katz thick smears were examined by experienced microscopists and helminth eggs were counted and expressed as eggs per gram of stool (EPG). Mean egg counts were significantly higher with the conventional light microscope (5,190 EPG versus 2,386 EPG for Ascaris lumbricoides; 826 versus 456 for Trichuris trichiura; both P Newton Nm1 microscope may be a useful tool for the detection and quantification of soil-transmitted helminth infection in clinical, epidemiologic, and public health settings. © The American Society of Tropical Medicine and Hygiene.

Telemedicine and Alzheimer's Disease from Studio-Based Videoconferencing to Mobile Handheld Cell Phones

Directory of Open Access Journals (Sweden)

Pk (Poh-Kooi Loh

2009-01-01

Full Text Available The use of Telemedicine in the assessment of cognitive impairment and Alzheimer's Disease is evolving with advances in Information and Communication Technology. This article outlines the course of evolution in Western Australia, a large state with a sparse population outside of the capital city. The starting point of the evolution, video-conferencing in Telehealth studios, is reviewed as well as the next stage, use of desktop technology, which enables the physician to consult from the office or clinic. A pilot study currently being undertaken to assess the validity of the latest stage in evolution of Telehealth—the use of handheld mobile cell phone video calling that allows the physician and patient to interact at locations convenient to both parties. The pitfalls and implications of the use of this stage, should it prove to be a valid approach, are discussed.

Handheld readout electronics to fully exploit the particle discrimination capabilities of elpasolite scintillators

Energy Technology Data Exchange (ETDEWEB)

Budden, B.S., E-mail: bbudden@lanl.gov [Intelligence and Space Research Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Stonehill, L.C.; Warniment, A.; Michel, J.; Storms, S.; Dallmann, N.; Coupland, D.D.S.; Stein, P.; Weller, S.; Borges, L.; Proicou, M.; Duran, G. [Intelligence and Space Research Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Kamto, J. [Intelligence and Space Research Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Electrical & Computer Engineering Department, Praire View A& M University, Prairie View, TX 77446 (United States)

2015-09-21

A new class of elpasolite scintillators has garnered recent attention due to the ability to perform as simultaneous gamma spectrometers and thermal neutron detectors. Such a dual-mode capability is made possible by pulse-shape discrimination (PSD), whereby the emission waveform profiles of gamma and neutron events are fundamentally unique. To take full advantage of these materials, we have developed the Compact Advanced Readout Electronics for Elpasolites (CAREE). This handheld instrument employs a multi-channel PSD-capable ASIC, custom micro-processor board, front-end electronics, power supplies, and a 2 in. photomultiplier tube for readout of the scintillator. The unit is highly configurable to allow for performance optimization amongst a wide sample of elpasolites which provide PSD in fundamentally different ways. We herein provide an introduction to elpasolites, then describe the motivation for the work, mechanical and electronic design, and preliminary performance results.

Digital knowledge in the coat pocket - hand-held personal digital assistants in radiology

International Nuclear Information System (INIS)

Niehues, S.M.; Froehlich, M.; Felix, R.; Lemke, A.J.

2004-01-01

The personal digital assistant (PDA) enables the independent access to large data in a pocket-sized format. The applications for hand-held computers are growing steadily and can support almost any kind of problem. An overview of the available hardware and software is provided and evaluated. Furthermore, the use of the PDA in the clinical daily routine is described. In view of the numerous software programs available in radiology, the range of software solutions for radiologists is presented. Despite the high acquisition cost, the PDA has already become the digital assistant for the radiologist. After a short time of getting used to the PDA, nobody wants to miss it at work or at home. New technical features and available software programs will continuously increase the integration of the PDA into the medical workflow in the near future. (orig.)

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

Science.gov (United States)

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.

Initial Experience with a Handheld Device Digital Imaging and Communications in Medicine Viewer: OsiriX Mobile on the iPhone

OpenAIRE

Choudhri, Asim F.; Radvany, Martin G.

2010-01-01

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 o...

Three-dimensional modeling of physiological tremor for hand-held surgical robotic instruments.

Science.gov (United States)

Tatinati, Sivanagaraja; Yan Naing Aye; Pual, Anand; Wei Tech Ang; Veluvolu, Kalyana C

2016-08-01

Hand-held robotic instruments are developed to compensate physiological tremor in real-time while augmenting the required precision and dexterity into normal microsurgical work-flow. The hardware (sensors and actuators) and software (causal linear filters) employed for tremor identification and filtering introduces time-varying unknown phase-delay that adversely affects the device performance. The current techniques that focus on three-dimensions (3D) tip position control involves modeling and canceling the tremor in 3-axes (x, y, and z axes) separately. Our analysis with the tremor data recorded from surgeons and novice subjects show that there exists significant correlation in tremor motion across the dimensions. Motivated by this, a new multi-dimensional modeling approach based on extreme learning machines (ELM) is proposed in this paper to correct the phase delay and to accurately model tremulous motion in three dimensions simultaneously. A study is conducted with tremor data recorded from the microsurgeons to analyze the suitability of proposed approach.

A positioning sensor for tonometric applications

NARCIS (Netherlands)

den Besten, C.; den Besten, C.; Bergveld, Piet

1992-01-01

In this paper we present a sensor, which is designed for application in a tonometer, an instrument for the measurement of intraocular pressure. The sensor measures diameter and position of a part of the eye globe that is flattened by the tonometer. The sensor principle is based on a change in

Beyond Textbook Illustrations: Hand-Held Models of Ordered DNA and Protein Structures as 3D Supplements to Enhance Student Learning of Helical Biopolymers

Science.gov (United States)

Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

2010-01-01

Textbook illustrations of 3D biopolymers on printed paper, regardless of how detailed and colorful, suffer from its two-dimensionality. For beginners, computer screen display of skeletal models of biopolymers and their animation usually does not provide the at-a-glance 3D perception and details, which can be done by good hand-held models. Here, we…

Evaluation of Handheld Scanners for Automotive Applications

Directory of Open Access Journals (Sweden)

Wadea Ameen

2018-01-01

Full Text Available The process of generating a computerized geometric model for an existing part is known as Reverse Engineering (RE. It is a very useful technique in product development and plays a significant role in automotive, aerospace, and medical industries. In fact, it has been getting remarkable attention in manufacturing industries owing to its advanced data acquisition technologies. The process of RE is based on two primary steps: data acquisition (also known as scanning and data processing. To facilitate point data acquisition, a variety of scanning systems is available with different capabilities and limitations. Although the optical control of 3D scanners is fully developed, still several factors can affect the quality of the scanned data. As a result, the proper selection of scanning parameters, such as resolution, laser power, shutter time, etc., becomes very crucial. This kind of investigation can be very helpful and provide its users with guidelines to identify the appropriate factors. Moreover, it is worth noting that no single system is ideal in all applications. Accordingly, this work has compared two portable (handheld systems based on laser scanning and white light optical scanning for automotive applications. A car door containing a free-form surface has been used to achieve the above-mentioned goal. The design of experiments has been employed to determine the effects of different scanning parameters and optimize them. The capabilities and limitations have been identified by comparing the two scanners in terms of accuracy, scanning time, triangle numbers, ease of use, and portability. Then, the relationships between the system capabilities and the application requirements have been established. The results revealed that the laser scanner performed better than the white light scanner in terms of accuracy, while the white light scanner performed better in terms of acquisition speed and triangle numbers.

A Systematic Review Regarding Tonometry and the Transmission of Infectious Diseases

Science.gov (United States)

Atkins, Nicole; Hodge, William; Li, Bruce

2018-01-01

Tonometry has been identified as a common method for measuring the intraocular pressure in patients. The direct contact between the tonometer and the eye may contribute to the risk of cross infection, especially of viral particles, from one patient to another. A systematic review was undertaken to address the likelihood of human immunodeficiency virus (HIV), hepatitis B virus, hepatitis C virus, and prion diseases transmission through the use of tonometers. Additionally, a comparison of the current tonometer disinfection methods is provided to assist with identifying which technique effectively reduces the risk of disease transmission. An electronic literature search was conducted using the following databases: Web of Science, EMBASE, CINAHL, SCOPUS, Biosis Previews, Cochrane Library, PubMed, and Google Scholar. Dissertation indexes were also searched, and these included: Dissertations and Abstracts, and Dissertations and Abstracts - UK/Ireland. Additionally, the Clinicaltrials.gov trial registry was searched to identify any other relevant literature. Two independent reviewers critically appraised the articles retrieved through the literature search. In total, 11 unique studies were deemed relevant for this systematic review. The available evidence demonstrated that the use of tonometers contributes to the transmission of these infectious diseases in vitro. The results also demonstrated variability in determining the most effective tonometer sterilization technique against these infectious diseases in vitro. There was limited evidence available regarding the transmission of HIV, hepatitis B, hepatitis C, and prion diseases through the use of tonometers. Additionally, due to the variability regarding the most effective sterilization techniques, it is difficult to identify which sterilization technique is most effective or adequately effective against these infectious diseases. Future research studies regarding infectious disease transmission through tonometry and

A Systematic Review Regarding Tonometry and the Transmission of Infectious Diseases.

Science.gov (United States)

Atkins, Nicole; Hodge, William; Li, Bruce

2018-03-01

Tonometry has been identified as a common method for measuring the intraocular pressure in patients. The direct contact between the tonometer and the eye may contribute to the risk of cross infection, especially of viral particles, from one patient to another. A systematic review was undertaken to address the likelihood of human immunodeficiency virus (HIV), hepatitis B virus, hepatitis C virus, and prion diseases transmission through the use of tonometers. Additionally, a comparison of the current tonometer disinfection methods is provided to assist with identifying which technique effectively reduces the risk of disease transmission. An electronic literature search was conducted using the following databases: Web of Science, EMBASE, CINAHL, SCOPUS, Biosis Previews, Cochrane Library, PubMed, and Google Scholar. Dissertation indexes were also searched, and these included: Dissertations and Abstracts, and Dissertations and Abstracts - UK/Ireland. Additionally, the Clinicaltrials.gov trial registry was searched to identify any other relevant literature. Two independent reviewers critically appraised the articles retrieved through the literature search. In total, 11 unique studies were deemed relevant for this systematic review. The available evidence demonstrated that the use of tonometers contributes to the transmission of these infectious diseases in vitro . The results also demonstrated variability in determining the most effective tonometer sterilization technique against these infectious diseases in vitro . There was limited evidence available regarding the transmission of HIV, hepatitis B, hepatitis C, and prion diseases through the use of tonometers. Additionally, due to the variability regarding the most effective sterilization techniques, it is difficult to identify which sterilization technique is most effective or adequately effective against these infectious diseases. Future research studies regarding infectious disease transmission through tonometry and

Handheld and mobile hyperspectral imaging sensors for wide-area standoff detection of explosives and chemical warfare agents

Science.gov (United States)

Gomer, Nathaniel R.; Gardner, Charles W.; Nelson, Matthew P.

2016-05-01

Hyperspectral imaging (HSI) is a valuable tool for the investigation and analysis of targets in complex background with a high degree of autonomy. HSI is beneficial for the detection of threat materials on environmental surfaces, where the concentration of the target of interest is often very low and is typically found within complex scenery. Two HSI techniques that have proven to be valuable are Raman and shortwave infrared (SWIR) HSI. Unfortunately, current generation HSI systems have numerous size, weight, and power (SWaP) limitations that make their potential integration onto a handheld or field portable platform difficult. The systems that are field-portable do so by sacrificing system performance, typically by providing an inefficient area search rate, requiring close proximity to the target for screening, and/or eliminating the potential to conduct real-time measurements. To address these shortcomings, ChemImage Sensor Systems (CISS) is developing a variety of wide-field hyperspectral imaging systems. Raman HSI sensors are being developed to overcome two obstacles present in standard Raman detection systems: slow area search rate (due to small laser spot sizes) and lack of eye-safety. SWIR HSI sensors have been integrated into mobile, robot based platforms and handheld variants for the detection of explosives and chemical warfare agents (CWAs). In addition, the fusion of these two technologies into a single system has shown the feasibility of using both techniques concurrently to provide higher probability of detection and lower false alarm rates. This paper will provide background on Raman and SWIR HSI, discuss the applications for these techniques, and provide an overview of novel CISS HSI sensors focused on sensor design and detection results.

Hand-held dynamic visual noise reduces naturally occurring food cravings and craving-related consumption.

Science.gov (United States)

Kemps, Eva; Tiggemann, Marika

2013-09-01

This study demonstrated the applicability of the well-established laboratory task, dynamic visual noise, as a technique for reducing naturally occurring food cravings and subsequent food intake. Dynamic visual noise was delivered on a hand-held computer device. Its effects were assessed within the context of a diary study. Over a 4-week period, 48 undergraduate women recorded their food cravings and consumption. Following a 2-week baseline, half the participants watched the dynamic visual noise display whenever they experienced a food craving. Compared to a control group, these participants reported less intense cravings. They were also less likely to eat following a craving and consequently consumed fewer total calories following craving. These findings hold promise for curbing unwanted food cravings and craving-driven consumption in real-world settings. Copyright © 2013 Elsevier Ltd. All rights reserved.

A hand-held 3D laser scanning with global positioning system of subvoxel precision

International Nuclear Information System (INIS)

Arias, Nestor; Meneses, Nestor; Meneses, Jaime; Gharbi, Tijani

2011-01-01

In this paper we propose a hand-held 3D laser scanner composed of an optical head device to extract 3D local surface information and a stereo vision system with subvoxel precision to measure the position and orientation of the 3D optical head. The optical head is manually scanned over the surface object by the operator. The orientation and position of the 3D optical head is determined by a phase-sensitive method using a 2D regular intensity pattern. This phase reference pattern is rigidly fixed to the optical head and allows their 3D location with subvoxel precision in the observation field of the stereo vision system. The 3D resolution achieved by the stereo vision system is about 33 microns at 1.8 m with an observation field of 60cm x 60cm.

The Complimentary Role of Methoxy-Isobutyl-Isonitrile and Hand-Held Gamma Probe in Adamantinoma

Science.gov (United States)

Maharaj, Masha; Korowlay, Nisaar; Ellmann, Prof

2016-01-01

Adamantinoma is a rare locally aggressive osteolytic tumor that is found 90% of the time in the diaphysis of the tibia with the remaining lesions found in the fibula and long tubular bones. A case of adamantinoma of the tibia is presented. The added value of nuclear medicine investigations in the workup of this patient is described. A three-phase whole body 99mTc-methylene diphosphonate bone and a whole body 99mTc-methoxy-isobutyl-isonitrile scans were complimentary in the demarcation of viable bone tumor and the assessment of the remainder of the bone and soft tissue to exclude other sites. Intra-operative assistance with a hand-held gamma probe, guided the biopsy of the most metabolically active tumor tissue. Histology revealed a biphasic tumor composed of epithelial and fibrous components, in keeping with an adamantinoma. PMID:26912979

Effect of acute intraocular pressure elevation on the minimum rim width in normal, ocular hypertensive and glaucoma eyes.

Science.gov (United States)

Sharma, Sourabh; Tun, Tin A; Baskaran, Mani; Atalay, Eray; Thakku, Sri Gowtham; Liang, Zhang; Milea, Dan; Strouthidis, Nicholas G; Aung, Tin; Girard, Michael Ja

2018-01-01

To estimate and compare changes in the Bruch's membrane opening-minimum rim width (BMO-MRW) and area in normal, ocular hypertensive and glaucoma eyes following acute elevations in intraocular pressure (IOP). The optic nerve heads (ONHs) of 104 subjects (31 normals, 20 ocular hypertension (OHT) and 53 with primary glaucoma) were imaged using Spectral-domain optical coherence tomography (OCT; Spectralis, Heidelberg Engineering, Germany). IOP was raised twice by applying a force (0.64 n then 0.9 n) to the anterior sclera using an ophthalmo-dynamometer. After each IOP increment, IOP was held constant, measured with a Tonopen (AVIA applanation tonometer, Reichert, Depew, New York, USA), and ONH was rescanned with OCT. In each OCT volume, BMO-MRW and area were calculated and at each IOP increment. The baseline MRW was significantly smaller in glaucoma subjects (174.3±54.3 µm) compared with normal (287.4±42.2 µm, pglaucoma subjects was significantly thinner at the first and second IOP elevations than that at baseline (both p0.05). Acute IOP elevation leads to compression of the nerve fibre layers of neuroretinal rim in glaucoma subjects only without changing ONH size. This suggests that the neural and connective tissues at ONH level in glaucoma subjects are more susceptible to acute IOP episodes than OHT or normal controls. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Understanding practice patterns of glaucoma sub-specialists in India

Directory of Open Access Journals (Sweden)

Nikhil S. Choudhari

2017-10-01

Full Text Available AIM: To obtain information on the prevailing practice patterns of glaucoma specialists in India. METHODS: Glaucoma specialists attending the Annual Conference of the Glaucoma Society of India (GSI were surveyed. This survey, conducted in 2013, was based on an interactive audience response system. RESULTS: The information was obtained from 146 glaucoma specialists. Approximately half (n=83; 57% had ≥10y of experience in managing glaucoma and were in institutional practice (n=74, 51%. Goldmann applanation tonometry was preferred by 103 (72% specialists whilst n=25 (17.4% used non-contact tonometer. Indentation gonioscopy was favoured by two-thirds (n=90, 66% whereas stereoscopic optic disc examination and visual fields using Humphrey perimeter was performed by a majority of the specialists surveyed (n=115, 86% and n=114; 83% respectively. Nearly three quarter specialists (n=96; 72% preferred optical coherence tomography for imaging. The primary choice for treatment of angle closure disease and primary open angle glaucoma was laser (iridotomy, n=117; 93% and medical management (prostaglandin analogue, n=104; 78%, respectively. Approximately only a third of the specialists surveyed (n=37; 28% were performing both trabeculectomy and implantation of a glaucoma drainage device and about half (n=64; 47% were not operating on congenital glaucoma at all. CONCLUSION: This survey has found conformance with preferred practice patterns in several areas of diagnosis and management of glaucoma, but there was diversity in a few areas. The information is a significant step towards improvement of glaucoma care in India, including planning for future strategies.

The effects of two different types of bandage contact lenses on the healthy canine eye.

Science.gov (United States)

Braus, Barbara Katharina; Riedler, Daniela; Tichy, Alexander; Spergser, Joachim; Schwendenwein, Ilse

2018-02-06

To compare two types of bandage contact lenses on the healthy canine eye. Six healthy Beagles. Two different types of bandage contact lenses (single sized human silicone contact lens 'PureVision 2' (Bausch & Lomb Incorporated, Rochester, NY, USA) and specially designed veterinary hydrogel contact lens 'AcriVet Pat D' (Bausch & Lomb Incorporated) were placed in 12 eyes of healthy Beagle dogs. Retention times and the effects of the lenses regarding irritation of the eye, changes in tear production, impact of contact lenses on tonometric readings, and cytologic and microbiological alterations of the canine eye were investigated. Mean retention times for veterinary hydrogel lenses with special dimensions were significantly shorter (2 days) than for one size human silicon lenses (8.8 days). Irritation scores were overall low for both types of lenses apart from one human lens causing severe irritation and keratoconjunctivitis as a sequel to folding and displacement. Tear production remained stable in human contact lenses. Intraocular pressure readings with a contact lens in place were only slightly altered; the most accurate readings were obtained through a human lens with an applanation tonometer. Cytology revealed a slight, nonsignificant increase in neutrophilic granulocytes with both types of lenses; the microflora did not change significantly. Human silicone lenses have significantly longer retention times and are less expensive than veterinary hydrogel lenses. In regard to irritation, bacterial growth and inflammation, both types of lenses can be recommended for use in canine eyes. © 2018 American College of Veterinary Ophthalmologists.

Seasonal and diurnal variations of ocular pressure in ocular hypertensive subjects in Pakistan.

Science.gov (United States)

Qureshi, I A; Xiao, R X; Yang, B H; Zhang, J; Xiang, D W; Hui, J L

1999-05-01

Studies have been shown that intraocular pressure (IOP) shows a diurnal variation in ocular hypertensive subjects, but the amount of change differs from study to study. In recent years it has been noted that intraocular pressure is a dynamic function and is subjected to many influences both acutely and over the long term. The variability in the results may be due to negligence of factors that can affect IOP. Moreover, seasonal variations in the ocular hypertensive subjects have never been described. After placing control on those factors that can affect IOP, this study investigated seasonal and diurnal variations in IOP of ocular hypertensive subjects. IOP was measured each month over the course of 12 months with the Goldmann applanation tonometer in 91 ocular hypertensive male subjects. To see the diurnal changes, subjects were asked to stay in the hospital for 24 hours. The average IOP in the winter months was higher than those in spring, summer, and autumn. The IOP difference between winter and summer was (mean +/- sem) 2.9 +/- 0.9 mmHg (p < 0.001). The peak of mean IOP in diurnal variation curve (25.7 +/- 1.2 mmHg) appeared in the morning when the subjects had just awaken. The mean diurnal variation was found to be 4.2 +/- 0.6 mmHg (p < 0.001). This study confirms that seasons influence IOP and it shows diurnal variations. As compared to other nations, diurnal variations in ocular hypertensive subjects seem to be somewhat less in Pakistan. Knowledge of the seasonal and diurnal variations in IOP may help glaucoma screeners.

Modalities of Tonometry and their Accuracy with Respect to Corneal Thickness and Irregularities

Directory of Open Access Journals (Sweden)

Carlos Gustavo V. De Moraes

2008-01-01

Each of the many different commercially available tonometers has specific advantages and disadvantages. New non-invasive technologies are getting closer to a precise estimation of the true IOP. However, among all tonometers, none is highly accurate when both corneal thickness and surface irregularities are present. Fifty years after its development, Goldmann tonometry remains the gold standard to which all other devices are compared.

Handheld echocardiography during hospitalization for acute myocardial infarction.

Science.gov (United States)

Cullen, Michael W; Geske, Jeffrey B; Anavekar, Nandan S; Askew, J Wells; Lewis, Bradley R; Oh, Jae K

2017-11-01

Handheld echocardiography (HHE) is concordant with standard transthoracic echocardiography (TTE) in a variety of settings but has not been thoroughly compared to traditional TTE in patients with acute myocardial infarction (AMI). Completed by experienced operators, HHE provides accurate diagnostic capabilities compared with standard TTE in AMI patients. This study prospectively enrolled patients admitted to the coronary care unit with AMI. Experienced sonographers performed HHE with a V-scan. All patients underwent clinical TTE. Each HHE was interpreted by 2 experts blinded to standard TTE. Agreement was assessed with κ statistics and concordance correlation coefficients. Analysis included 82 patients (mean age, 66 years; 74% male). On standard TTE, mean left ventricular (LV) ejection fraction was 46%. Correlation coefficients between HHE and TTE were 0.75 (95% confidence interval: 0.66 to 0.82) for LV ejection fraction and 0.69 (95% confidence interval: 0.58 to 0.77) for wall motion score index. The κ statistics ranged from 0.47 to 0.56 for LV enlargement, 0.55 to 0.79 for mitral regurgitation, and 0.44 to 0.57 for inferior vena cava dilatation. The κ statistics were highest for the anterior (0.81) and septal (0.71) apex and lowest for the mid inferolateral (0.36) and basal inferoseptal (0.36) walls. In patients with AMI, HHE and standard TTE demonstrate good correlation for LV function and wall motion. Agreement was less robust for structural abnormalities and specific wall segments. In experienced hands, HHE can provide a focused assessment of LV function in patients hospitalized with AMI; however, HHE should not substitute for comprehensive TTE. © 2017 Wiley Periodicals, Inc.

Into the Wild: Neuroergonomic Differentiation of Hand-Held and Augmented Reality Wearable Displays during Outdoor Navigation with Functional Near Infrared Spectroscopy.

Science.gov (United States)

McKendrick, Ryan; Parasuraman, Raja; Murtza, Rabia; Formwalt, Alice; Baccus, Wendy; Paczynski, Martin; Ayaz, Hasan

2016-01-01

Highly mobile computing devices promise to improve quality of life, productivity, and performance. Increased situation awareness and reduced mental workload are two potential means by which this can be accomplished. However, it is difficult to measure these concepts in the "wild". We employed ultra-portable battery operated and wireless functional near infrared spectroscopy (fNIRS) to non-invasively measure hemodynamic changes in the brain's Prefrontal cortex (PFC). Measurements were taken during navigation of a college campus with either a hand-held display, or an Augmented reality wearable display (ARWD). Hemodynamic measures were also paired with secondary tasks of visual perception and auditory working memory to provide behavioral assessment of situation awareness and mental workload. Navigating with an augmented reality wearable display produced the least workload during the auditory working memory task, and a trend for improved situation awareness in our measures of prefrontal hemodynamics. The hemodynamics associated with errors were also different between the two devices. Errors with an augmented reality wearable display were associated with increased prefrontal activity and the opposite was observed for the hand-held display. This suggests that the cognitive mechanisms underlying errors between the two devices differ. These findings show fNIRS is a valuable tool for assessing new technology in ecologically valid settings and that ARWDs offer benefits with regards to mental workload while navigating, and potentially superior situation awareness with improved display design.

An Enhanced Intelligent Handheld Instrument with Visual Servo Control for 2-DOF Hand Motion Error Compensation

Directory of Open Access Journals (Sweden)

Yan Naing Aye

2013-10-01

Full Text Available The intelligent handheld instrument, ITrem2, enhances manual positioning accuracy by cancelling erroneous hand movements and, at the same time, provides automatic micromanipulation functions. Visual data is acquired from a high speed monovision camera attached to the optical surgical microscope and acceleration measurements are acquired from the inertial measurement unit (IMU on board ITrem2. Tremor estimation and canceling is implemented via Band-limited Multiple Fourier Linear Combiner (BMFLC filter. The piezoelectric actuated micromanipulator in ITrem2 generates the 3D motion to compensate erroneous hand motion. Preliminary bench-top 2-DOF experiments have been conducted. The error motions simulated by a motion stage is reduced by 67% for multiple frequency oscillatory motions and 56.16% for pre-conditioned recorded physiological tremor.

Effects of topical hypotensive drugs on circadian IOP, blood pressure, and calculated diastolic ocular perfusion pressure in patients with glaucoma.

Science.gov (United States)

Quaranta, Luciano; Gandolfo, Federico; Turano, Raffaele; Rovida, Federico; Pizzolante, Teodoro; Musig, Andrea; Gandolfo, Enrico

2006-07-01

To compare the short-term effects of timolol 0.5%, brimonidine 0.2%, dorzolamide 2%, and latanoprost 0.005% on intraocular pressure (IOP), blood pressure (BP), and diastolic ocular perfusion pressure (DOPP), calculated as the difference between the diastolic blood pressure (DBP) and IOP. According to a 4 x 4 Latin squares design for repeated measures, 27 untreated patients and patients with newly diagnosed primary open-angle glaucoma (POAG) were treated with timolol 0.5% at 8 AM and 8 PM; brimonidine 0.2% at 8 AM and 8 PM; dorzolamide 2% at 8 AM, 2 PM, and 8 PM; and latanoprost 0.005% at 8 PM. The duration of each treatment course was 6-weeks, with a 4-week washout between each treatment. IOP and BP were measured at baseline and at the end of each treatment period. IOP was measured every 2 hours throughout a 24-hour period. Sitting IOP was measured from 8 AM to 10 PM by Goldmann applanation tonometry. Supine IOP was assessed from 12 to 6 AM by means of a handheld electronic tonometer (TonoPen XL; Mentor, Norwell, MA). BP monitoring was performed by means of an automated portable device (TM-2430; A & D Co., Saitama, Japan). All the drugs tested decreased the IOP significantly at all time points in comparison with baseline pressure. The mean 24-hour IOP after latanoprost administration (16.62+/-0.98 mm Hg) was significantly lower than that after timolol, brimonidine, or dorzolamide (P=0.0001). During the 24-hour period, brimonidine induced a significant decrease in systolic BP (SBP) and DBP at all time points when compared with baseline measurements and with those after administration of the other drugs (P<0.0001). Timolol caused a significant decrease in DBP and SBP at all the 24-hour time points when compared with the baseline and with the dorzolamide- and latanoprost-induced changes (P<0.0001). The mean 24-hour DOPPs were 50.7+/-5.9 mm Hg at baseline, 53+/-5.5 mm Hg with timolol, 46.2+/-5.4 mm Hg with brimonidine, 55.9+/-4.6 mm Hg with dorzolamide, and 56

Elemental Analysis of Bone, Teeth, Horn and Antler in Different Animal Species Using Non-Invasive Handheld X-Ray Fluorescence

Science.gov (United States)

Buddhachat, Kittisak; Klinhom, Sarisa; Siengdee, Puntita; Brown, Janine L.; Nomsiri, Raksiri; Kaewmong, Patcharaporn; Thitaram, Chatchote; Mahakkanukrauh, Pasuk; Nganvongpanit, Korakot

2016-01-01

Mineralized tissues accumulate elements that play crucial roles in animal health. Although elemental content of bone, blood and teeth of human and some animal species have been characterized, data for many others are lacking, as well as species comparisons. Here we describe the distribution of elements in horn (Bovidae), antler (Cervidae), teeth and bone (humerus) across a number of species determined by handheld X-ray fluorescence (XRF) to better understand differences and potential biological relevance. A difference in elemental profiles between horns and antlers was observed, possibly due to the outer layer of horns being comprised of keratin, whereas antlers are true bone. Species differences in tissue elemental content may be intrinsic, but also related to feeding habits that contribute to mineral accumulation, particularly for toxic heavy metals. One significant finding was a higher level of iron (Fe) in the humerus bone of elephants compared to other species. This may be an adaptation of the hematopoietic system by distributing Fe throughout the bone rather than the marrow, as elephant humerus lacks a marrow cavity. We also conducted discriminant analysis and found XRF was capable of distinguishing samples from different species, with humerus bone being the best source for species discrimination. For example, we found a 79.2% correct prediction and success rate of 80% for classification between human and non-human humerus bone. These findings show that handheld XRF can serve as an effective tool for the biological study of elemental composition in mineralized tissue samples and may have a forensic application. PMID:27196603

Elemental Analysis of Bone, Teeth, Horn and Antler in Different Animal Species Using Non-Invasive Handheld X-Ray Fluorescence.

Directory of Open Access Journals (Sweden)

Kittisak Buddhachat

Full Text Available Mineralized tissues accumulate elements that play crucial roles in animal health. Although elemental content of bone, blood and teeth of human and some animal species have been characterized, data for many others are lacking, as well as species comparisons. Here we describe the distribution of elements in horn (Bovidae, antler (Cervidae, teeth and bone (humerus across a number of species determined by handheld X-ray fluorescence (XRF to better understand differences and potential biological relevance. A difference in elemental profiles between horns and antlers was observed, possibly due to the outer layer of horns being comprised of keratin, whereas antlers are true bone. Species differences in tissue elemental content may be intrinsic, but also related to feeding habits that contribute to mineral accumulation, particularly for toxic heavy metals. One significant finding was a higher level of iron (Fe in the humerus bone of elephants compared to other species. This may be an adaptation of the hematopoietic system by distributing Fe throughout the bone rather than the marrow, as elephant humerus lacks a marrow cavity. We also conducted discriminant analysis and found XRF was capable of distinguishing samples from different species, with humerus bone being the best source for species discrimination. For example, we found a 79.2% correct prediction and success rate of 80% for classification between human and non-human humerus bone. These findings show that handheld XRF can serve as an effective tool for the biological study of elemental composition in mineralized tissue samples and may have a forensic application.

Elemental Analysis of Bone, Teeth, Horn and Antler in Different Animal Species Using Non-Invasive Handheld X-Ray Fluorescence.

Science.gov (United States)

Buddhachat, Kittisak; Klinhom, Sarisa; Siengdee, Puntita; Brown, Janine L; Nomsiri, Raksiri; Kaewmong, Patcharaporn; Thitaram, Chatchote; Mahakkanukrauh, Pasuk; Nganvongpanit, Korakot

2016-01-01

Mineralized tissues accumulate elements that play crucial roles in animal health. Although elemental content of bone, blood and teeth of human and some animal species have been characterized, data for many others are lacking, as well as species comparisons. Here we describe the distribution of elements in horn (Bovidae), antler (Cervidae), teeth and bone (humerus) across a number of species determined by handheld X-ray fluorescence (XRF) to better understand differences and potential biological relevance. A difference in elemental profiles between horns and antlers was observed, possibly due to the outer layer of horns being comprised of keratin, whereas antlers are true bone. Species differences in tissue elemental content may be intrinsic, but also related to feeding habits that contribute to mineral accumulation, particularly for toxic heavy metals. One significant finding was a higher level of iron (Fe) in the humerus bone of elephants compared to other species. This may be an adaptation of the hematopoietic system by distributing Fe throughout the bone rather than the marrow, as elephant humerus lacks a marrow cavity. We also conducted discriminant analysis and found XRF was capable of distinguishing samples from different species, with humerus bone being the best source for species discrimination. For example, we found a 79.2% correct prediction and success rate of 80% for classification between human and non-human humerus bone. These findings show that handheld XRF can serve as an effective tool for the biological study of elemental composition in mineralized tissue samples and may have a forensic application.

Calculation of induced current densities and specific absorption rates (SAR) for pregnant women exposed to hand-held metal detectors

International Nuclear Information System (INIS)

Kainz, Wolfgang; Chan, Dulciana D; Casamento, Jon P; Bassen, Howard I

2003-01-01

The finite difference time domain (FDTD) method in combination with a well established frequency scaling method was used to calculate the internal fields and current densities induced in a simple model of a pregnant woman and her foetus, when exposed to hand-held metal detectors. The pregnant woman and foetus were modelled using a simple semi-heterogeneous model in 10 mm resolution, consisting of three different types of tissue. The model is based on the scanned shape of a pregnant woman in the 34th gestational week. Nine different representative models of hand-held metal detectors operating in the frequency range from 8 kHz to 2 MHz were evaluated. The metal detectors were placed directly on the abdomen of the computational model with a spacing of 1 cm. Both the induced current density and the specific absorption rate (SAR) are well below the recommended limits for exposure of the general public published in the ICNIRP Guidelines and the IEEE C95.1 Standard. The highest current density is 8.3 mA m -2 and the highest SAR is 26.5 μW kg -1 . Compared to the limits for the induced current density recommended in the ICNIRP Guidelines, a minimum safety factor of 3 exists. Compared to the IEEE C95.1 Standard, a safety factor of 60,000 for the specific absorption rate was found. Based on the very low specific absorption rate and an induced current density below the recommended exposure limits, significant temperature rise or nerve stimulation in the pregnant woman or in the foetus can be excluded

Hand-held multi-DOF robotic forceps for neurosurgery designed for dexterous manipulation in deep and narrow space.

Science.gov (United States)

Okubo, Takuro; Harada, Kanako; Fujii, Masahiro; Tanaka, Shinichi; Ishimaru, Tetsuya; Iwanaka, Tadashi; Nakatomi, Hirohumi; Sora, Sigeo; Morita, Akio; Sugita, Naohiko; Mitsuishi, Mamoru

2014-01-01

Neurosurgical procedures require precise and dexterous manipulation of a surgical suture in narrow and deep spaces in the brain. This is necessary for surgical tasks such as the anastomosis of microscopic blood vessels and dura mater suturing. A hand-held multi-degree of freedom (DOF) robotic forceps was developed to aid the performance of such difficult tasks. The diameter of the developed robotic forceps is 3.5 mm, and its tip has three DOFs, namely, bending, rotation, and grip. Experimental results showed that the robotic forceps had an average needle insertion force of 1.7 N. Therefore, an increase in the needle insertion force is necessary for practical application of the developed device.

Characterization of wood dust emission from hand-held woodworking machines.

Science.gov (United States)

Keller, F-X; Chata, F

2018-01-01

This article focuses on the prevention of exposure to wood dust when operating electrical hand-held sawing and sanding machines. A laboratory methodology was developed to measure the dust concentration around machines during operating processes. The main objective was to characterize circular saws and sanders, with the aim of classifying the different power tools tested in terms of dust emission (high dust emitter vs. low dust emitter). A test set-up was developed and is described and a measurement methodology was determined for each of the two operations studied. The robustness of the experimental results is discussed and shows good tendencies. The impact of air-flow extraction rate was assessed and the pressure loss of the system for each machine established. For the circular saws, three machines over the nine tested could be classified in the low dust emitter group. Their mean concentration values measured are between 0.64 and 0.98 mg/m 3 for the low dust emitter group and from 2.55 and 4.37 mg/m 3 for the high dust emitter group. From concentration measurements, a machine classification is possible-one for sanding machines and one for sawing machines-and a ratio from 1-7 is obtained when comparing the results. This classification will be helpful when a choice of high performance power tools, in terms of dust emission, must be made by professionals.

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

Directory of Open Access Journals (Sweden)

Jean T Coulibaly

2016-06-01

Full Text Available 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

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

Science.gov (United States)

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

Hazardous metals in vintage plastic toys measured by a handheld X-ray fluorescence spectrometer.

Science.gov (United States)

Miller, Gillian Zaharias; Harris, Zoe E

2015-01-01

Over 100 plastic toys from the 1970s and 1980s, both polyvinyl chloride ("vinyl") and nonvinyl, were analyzed in the study described here using a handheld X-ray fluorescence spectrometer to quantify hazardous metal content. A sampling of recent vinyl toys was also tested. The majority of nonvinyl samples were Fisher Price brand toys. The vinyl toys consisted largely of Barbie dolls and other dolls. Overall, lead or cadmium was found in 67% of vintage plastic toys, frequently at concentrations exceeding current U.S. and European limits. Arsenic was detected at levels of concern in 16% of the samples. In the nonvinyl toys, heavy metal content was found to correlate with certain colors of plastic. The likely sources of the detected metals are discussed. None of the contemporary vinyl toys contained detectable cadmium, lead, or arsenic. Given that vintage toys remain in widespread use by children in homes and other locations, the results illuminate a potential source of heavy metal exposure for children.

Pre-test habituation improves the reliability of a handheld test of mechanical nociceptive threshold in dairy cows

DEFF Research Database (Denmark)

Raundal, P. M.; Andersen, P. H.; Toft, Nils

2015-01-01

Mechanical nociceptive threshold (MNT) testing has been used to investigate aspects of painful states in bovine claws. We investigated a handheld tool, where the applied stimulation force was monitored continuously relative to a pre-encoded based target force. The effect on MNT of two pre-testing...... habituation procedures was performed in two different experiments comprising a total of 88 sound Holsteins dairy cows kept either inside or outside their home environment. MNT testing was performed using five consecutive mechanical nociceptive stimulations per cow per test at a fixed pre-encoded target rate...... of 2.1 N/s. The habituation procedure performed in dairy cows kept in their home environment led to lowered intra-individual coefficient of variation of MNT (P test...

Duplication of complete dentures using general-purpose handheld optical scanner and 3-dimensional printer: Introduction and clinical considerations.

Science.gov (United States)

Kurahashi, Kosuke; Matsuda, Takashi; Goto, Takaharu; Ishida, Yuichi; Ito, Teruaki; Ichikawa, Tetsuo

2017-01-01

To introduce a new clinical procedure for fabricating duplicates of complete dentures by bite pressure impression using digital technology, and to discuss its clinical significance. The denture is placed on a rotary table and the 3-dimensional form of the denture is digitized using a general-purpose handheld optical scanner. The duplicate denture is made of polylactic acid by a 3-dimensional printer using the 3-dimensional data. This procedure has the advantages of wasting less material, employing less human power, decreasing treatment time at the chair side, lowering the rates of contamination, and being readily fabricated at the time of the treatment visit. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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.

A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

Energy Technology Data Exchange (ETDEWEB)

Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Jue, E-mail: zhangjue@pku.edu.cn; Fang, Jing [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China)

2015-10-15

A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

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

Science.gov (United States)

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.

Robust sleep quality quantification method for a personal handheld device.

Science.gov (United States)

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.

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

Science.gov (United States)

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

SU-F-J-140: Using Handheld Stereo Depth Cameras to Extend Medical Imaging for Radiation Therapy Planning

Energy Technology Data Exchange (ETDEWEB)

Jenkins, C; Xing, L; Yu, S [Stanford University, Stanford, CA (United States)

2016-06-15

Purpose: A correct body contour is essential for the accuracy of dose calculation in radiation therapy. While modern medical imaging technologies provide highly accurate representations of body contours, there are times when a patient’s anatomy cannot be fully captured or there is a lack of easy access to CT/MRI scanning. Recently, handheld cameras have emerged that are capable of performing three dimensional (3D) scans of patient surface anatomy. By combining 3D camera and medical imaging data, the patient’s surface contour can be fully captured. Methods: A proof-of-concept system matches a patient surface model, created using a handheld stereo depth camera (DC), to the available areas of a body contour segmented from a CT scan. The matched surface contour is then converted to a DICOM structure and added to the CT dataset to provide additional contour information. In order to evaluate the system, a 3D model of a patient was created by segmenting the body contour with a treatment planning system (TPS) and fabricated with a 3D printer. A DC and associated software were used to create a 3D scan of the printed phantom. The surface created by the camera was then registered to a CT model that had been cropped to simulate missing scan data. The aligned surface was then imported into the TPS and compared with the originally segmented contour. Results: The RMS error for the alignment between the camera and cropped CT models was 2.26 mm. Mean distance between the aligned camera surface and ground truth model was −1.23 +/−2.47 mm. Maximum deviations were < 1 cm and occurred in areas of high concavity or where anatomy was close to the couch. Conclusion: The proof-of-concept study shows an accurate, easy and affordable method to extend medical imaging for radiation therapy planning using 3D cameras without additional radiation. Intel provided the camera hardware used in this study.

Handheld skin printer: in situ formation of planar biomaterials and tissues.

Science.gov (United States)

Hakimi, Navid; Cheng, Richard; Leng, Lian; Sotoudehfar, Mohammad; Ba, Phoenix Qing; Bakhtyar, Nazihah; Amini-Nik, Saeid; Jeschke, Marc G; Günther, Axel

2018-05-15

We present a handheld skin printer that enables the in situ formation of biomaterial and skin tissue sheets of different homogeneous and architected compositions. When manually positioned above a target surface, the compact instrument (weight <0.8 kg) conformally deposits a biomaterial or tissue sheet from a microfluidic cartridge. Consistent sheet formation is achieved by coordinating the flow rates at which bioink and cross-linker solution are delivered, with the speed at which a pair of rollers actively translate the cartridge along the surface. We demonstrate compatibility with dermal and epidermal cells embedded in ionically cross-linkable biomaterials (e.g., alginate), and enzymatically cross-linkable proteins (e.g., fibrin), as well as their mixtures with collagen type I and hyaluronic acid. Upon rapid crosslinking, biomaterial and skin cell-laden sheets of consistent thickness, width and composition were obtained. Sheets deposited onto horizontal, agarose-coated surfaces were used for physical and in vitro characterization. Proof-of-principle demonstrations for the in situ formation of biomaterial sheets in murine and porcine excisional wound models illustrate the capacity of depositing onto inclined and compliant wound surfaces that are subject to respiratory motion. We expect the presented work will enable the in situ delivery of a wide range of different cells, biomaterials, and tissue adhesives, as well as the in situ fabrication of spatially organized biomaterials, tissues, and biohybrid structures.

A Handheld, Free Roaming, Data Display for DIII-D Diagnostic Data

International Nuclear Information System (INIS)

Broesch, J.D.; Phillips, J.C.; Petersen, P.I.; Hansink, M.J.

1999-01-01

Standard handheld test instruments such as voltmeters and portable oscilloscopes are useful for making basic measurements necessary for the operation and maintenance of large experiments such as the DIII-D magnetic fusion research facility. Some critical diagnostic information, however, is available only on system computers. Often this diagnostic information is located in computer databases and requires synthesis via computational algorithms to be of practical use to the technician. Unfortunately, this means the data is typically only available via computer screens located at fixed locations. One common way to provide mobile information is to have one operator sit at a console and read the data to the mobile technician via radio. This is inefficient in as much as it requires two people. Even more importantly the operator-to-technician voice link introduces significant delays and errors that may hinder response times. To address these concerns of personnel utilization and efficiency, we have developed a remote display based on an rf-data link that can be carried with a technician as he moves about the facility. This display can provide the technician with any information needed from the stationary database. This paper will discuss the overall architecture as well as the individual modules for the mobile data display. Lessons learned, as well as techniques for improving the usefulness of such systems, will be presented

Geocam Space: Enhancing Handheld Digital Camera Imagery from the International Space Station for Research and Applications

Science.gov (United States)

Stefanov, William L.; Lee, Yeon Jin; Dille, Michael

2016-01-01

Handheld astronaut photography of the Earth has been collected from the International Space Station (ISS) since 2000, making it the most temporally extensive remotely sensed dataset from this unique Low Earth orbital platform. Exclusive use of digital handheld cameras to perform Earth observations from the ISS began in 2004. Nadir viewing imagery is constrained by the inclined equatorial orbit of the ISS to between 51.6 degrees North and South latitude, however numerous oblique images of land surfaces above these latitudes are included in the dataset. While unmodified commercial off-the-shelf digital cameras provide only visible wavelength, three-band spectral information of limited quality current cameras used with long (400+ mm) lenses can obtain high quality spatial information approaching 2 meters/ground pixel resolution. The dataset is freely available online at the Gateway to Astronaut Photography of Earth site (http://eol.jsc.nasa.gov), and now comprises over 2 million images. Despite this extensive image catalog, use of the data for scientific research, disaster response, commercial applications and visualizations is minimal in comparison to other data collected from free-flying satellite platforms such as Landsat, Worldview, etc. This is due primarily to the lack of fully-georeferenced data products - while current digital cameras typically have integrated GPS, this does not function in the Low Earth Orbit environment. The Earth Science and Remote Sensing (ESRS) Unit at NASA Johnson Space Center provides training in Earth Science topics to ISS crews, performs daily operations and Earth observation target delivery to crews through the Crew Earth Observations (CEO) Facility on board ISS, and also catalogs digital handheld imagery acquired from orbit by manually adding descriptive metadata and determining an image geographic centerpoint using visual feature matching with other georeferenced data, e.g. Landsat, Google Earth, etc. The lack of full geolocation

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.

Science.gov (United States)

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

Prevalent practice patterns in glaucoma: Poll of Indian ophthalmologists at a national conference

Directory of Open Access Journals (Sweden)

Nikhil Shreeram Choudhari

2016-01-01

Full Text Available Purpose: The aim of this study is to explore and compare the prevailing practice patterns in the diagnosis and management of glaucoma among subspecialists and general ophthalmologists in India. Materials and Methods: This is an interactive audience response system (ARS based poll of ophthalmologists attending the annual conference of the Glaucoma Society of India in 2013. Results: The information was obtained from 379 ophthalmologists (146 glaucoma specialists, 54 nonglaucoma subspecialists, and 179 general ophthalmologists. The majority of polled ophthalmologists (236; 62% had 10 or more years of experience in ophthalmology. The glaucoma specialists differed from nonglaucomatologists in their preference for Goldmann applanation tonometer (P < 0.01, four-mirror gonioscope (P < 0.01, Humphrey perimeter (P < 0.01, laser peripheral iridotomy in primary angle closure disease (P = 0.03, postiridotomy gonioscopy (P < 0.01, and usage of antifibrotic agents during filtering surgery (P < 0.01. Optical coherence tomography was the most preferred imaging modality and was utilized more often by the subspecialists than general ophthalmologists. The ophthalmologists also differed in their choice of antiglaucoma medications. More glaucoma specialists were performing surgery on children with congenital glaucoma (P < 0.01, implanting glaucoma drainage devices (P < 0.01, and using scientific journals to upgrade knowledge (P = 0.03 than the other ophthalmologists. Conclusions: This poll is the first of its kind in India, in its usage of the ARS, and in comparing the practice patterns of care for glaucoma among subspecialists and general ophthalmologists. It has revealed substantial diversity in a few areas among those who did and did not receive specialty training in glaucoma.

Effects of hemodialysis on corneal and anterior chamber morphometry and intraocular pressure in patients with end-stage renal disease

Directory of Open Access Journals (Sweden)

Mehtap Caglayan

Full Text Available ABSTRACT Purpose: To evaluate the effects of hemodialysis (HD on corneal and anterior chamber morphometry, as well as intraocular pressure (IOP in patients with end-stage renal disease. Methods: Fifty right eyes were examined 30 minutes before and after HD. IOP was measured with a Goldmann applanation tonometer, and Ehlers' formula was used to calculate the corrected IOP values. The central corneal thickness (CCT, corneal volume (CV, keratometric values, anterior chamber depth (ACD, aqueous depth (AQD, anterior chamber volume (ACV, and anterior chamber angle (ACA in the nasal and temporal quadrants were measured with a Sirius anterior segment analysis system. Blood urea nitrogen levels, body mass, and systolic and diastolic arterial pressure were also measured before and after HD. Results: The mean age was 60.80 ± 13.38 (range: 35-80 years. The mean uncorrected and corrected IOP values decreased from 18.06 ± 3.91 and 18.31 ± 4.83 mmHg to 16.94 ± 3.87 and 16.95 ± 4.74 mmHg after HD, respectively (p=0.011 and p=0.003, respectively. The mean CCT decreased from 536.38 ± 24.73 to 533.18 ± 27.25 µm (p=0.002, and the mean CV decreased from 57.52 ± 3.15 to 55.68 ± 3.55 mm³ (p0.05 for all values. There were no significant correlations between the ocular and systemic parameters (p>0.05 for all correlations. Conclusions: Uncorrected IOP, corrected IOP, CCT, and CV values decreased after HD, whereas the anterior chamber morphometry values remained similar between the measurements performed before and after HD.

Effect of intravenous metoclopramide on intraocular pressure: A prospective, randomized, double-blind, placebo-controlled study

Directory of Open Access Journals (Sweden)

Sudheera K

2008-01-01

Full Text Available Background: Prevention of rise in intraocular pressure (IOP is essential in patients undergoing surgery for perforated eye injuries. Metoclopramide, a prokinetic agent, is commonly used to hasten gastric emptying in emergency surgeries. Aim: To study the change in IOP after intravenous metoclopramide and to study the influence of metoclopramide on change in IOP after succinylcholine and tracheal intubation. Settings and Design: A randomized, double-blind, placebo-controlled study of 60 patients undergoing non-ophthalmic elective surgery. Materials and Methods: Sixty American Society of Anesthesiologists (ASA I adult patients were randomly assigned to receive normal saline (Group C or metoclopramide 10 mg (Group M 30 min before the induction of anesthesia. Thiopentone was used for induction and succinylcholine for tracheal intubation. Intraocular pressure was measured in both the eyes pre and post drug treatment and succinylcholine and tracheal intubation using Perkins applanation tonometer. Statistical Analysis: Student′s t-test and repeated measures ANOVA were used. A P value < 0.05 was considered as significant. Results: Intraocular pressure was consistently lower in Group M than in Group C after the test drug, though the difference was not statistically significant. Intraocular pressure decreased significantly after administration of thiopentone and increased significantly in Groups C and M after tracheal intubation ( P < 0.01. Intraocular pressure was comparable between the groups at all the times. Conclusions: Metoclopramide does not cause a clinically significant change in IOP nor does it influence the changes in IOP during anesthesia and tracheal intubation. Metoclopramide shows a trend towards decrease in IOP, though clinically insignificant. Therefore metoclopramide can be used to promote gastric emptying in patients with perforated eye injury.

Comparison of sugammadex and neostigmine-atropine on intraocular pressure and postoperative effects.

Science.gov (United States)

Hakimoğlu, Sedat; Tuzcu, Kasım; Davarcı, Işıl; Karcıoğlu, Murat; Ayhan Tuzcu, Esra; Hancı, Volkan; Aydın, Suzan; Kahraman, Hilal; Elbeyli, Ahmet; Turhanoğlu, Selim

2016-02-01

During surgery, changes in intraocular pressure (IOP) can be observed resulting from several factors, such as airway manipulations and drugs used. We aimed to investigate the effects of sugammadex and neostigmine on IOP, hemodynamic parameters, and complications after extubation. Our study comprised 60 patients, aged 18-65 years, with a risk status of the American Society of Anesthesiologists I-II who underwent arthroscopic surgery under general anesthesia. The patients were randomly assigned into two groups. At the end of the surgery, the neuromuscular block was reversed using neostigmine (50 μg/kg) plus atropine (15 μg/kg) in Group 1, and sugammadex (4 mg/kg) in Group 2. Neuromuscular blockade was monitored using acceleromyography and a train-of-four mode of stimulation. IOP was measured before induction and at 30 seconds, 2 minutes, and 10 minutes after extubation. A Tono-Pen XL applanation tonometer was used to measure IOP. This showed that elevation in IOP of patients reversed using sugammadex was similar to that recorded in patients reversed using neostigmine-atropine. When heart rate was compared, there was a significant difference between basal values and those obtained at 30 seconds and 10 minutes after extubation in the neostigmine-atropine group. Extubation time (time from withdrawal of anesthetic gas to extubation) was significantly shorter in the sugammadex group (p = 0.003) than in the neostigmine-atropine group. The postextubation IOP values of the sugammadex group were similar to the neostigmine-atropine group. Extubation time (time from withdrawal of anesthetic gas to extubation) was significantly shorter in the sugammadex group (p = 0.003) than in the neostigmine-atropine group. Copyright © 2016. Published by Elsevier Taiwan.

Drift from the Use of Hand-Held Knapsack Pesticide Sprayers in Boyacá (Colombian Andes).

Science.gov (United States)

García-Santos, Glenda; Feola, Giuseppe; Nuyttens, David; Diaz, Jaime

2016-05-25

Offsite pesticide losses in tropical mountainous regions have been little studied. One example is measuring pesticide drift soil deposition, which can support pesticide risk assessment for surface water, soil, bystanders, and off-target plants and fauna. This is considered a serious gap, given the evidence of pesticide-related poisoning in those regions. Empirical data of drift deposition of a pesticide surrogate, Uranine tracer, within one of the highest potato-producing regions in Colombia, characterized by small plots and mountain orography, is presented. High drift values encountered in this study reflect the actual spray conditions using hand-held knapsack sprayers. Comparison between measured and predicted drift values using three existing empirical equations showed important underestimation. However, after their optimization based on measured drift information, the equations showed a strong predictive power for this study area and the study conditions. The most suitable curve to assess mean relative drift was the IMAG calculator after optimization.