Social representation of fair price among professional photographers.

We investigated the social representation of fair price of French and English-speaking photographers using the free association method. In two independent studies, we performed a factorial analysis of correspondence of the words provided by the participants as well as a similitude analysis. The results indicated that "fair price" was mainly associated with time, effort and experience level of photographers. Both French- and English-speaking samples made similar associations around the concept of fair price but the order of importance varied. We observed some gender-related differences in both samples, although the relative number of male and female participants must be taken into consideration.

Remote monitoring of clubfoot treatment with digital photographs in low resource settings: Is it accurate?

BACKGROUND: Clinical examination and functional assessment are often the first steps to assess outcome of clubfoot treatment. Clinical photographs may be an adjunct used to assess treatment outcomes in lower resourced settings where physical review by a specialist is limited. We aimed to evaluate the diagnostic performance of photographic images of patients with clubfoot in assessing outcome following treatment. METHODS: In this single-centre diagnostic accuracy study, we included all children with clubfoot from a cohort treated between 2011 and 2013, in 2017. Two physiotherapists trained in clubfoot management calculated the Assessing Clubfoot Treatment (ACT) score for each child to decide if treatment was successful or if further treatment was required. Photographic images were then taken of 79 feet. Two blinded orthopaedic surgeons assessed three sets of images of each foot (n = 237 in total) at two time points (two months apart). Treatment for each foot was rated as 'success', 'borderline' or 'failure'. Intra- and inter-observer variation for the photographic image was assessed. Sensitivity, specificity, positive and negative predictive values were calculated for the photographic image compared to the ACT score. RESULTS: There was perfect correlation between clinical assessment and photographic evaluation of both raters at both time-points in 38 (48%) feet. The raters demonstrated acceptable reliability with re-scoring photographs (rater 1, k = 0.55; rater 2, k = 0.88). Thirty percent (n = 71) of photographs were assessed as poor quality image or sub-optimal patient position. Sensitivity of outcome with photograph compared to ACT score was 83.3%-88.3% and specificity ranged from 57.9%-73.3%. CONCLUSION: Digital photography may help to confirm, but not exclude, success of clubfoot treatment. Future work to establish photographic parameters as an adjunct to assessing treatment outcomes, and guidance on a standardised protocol for photographs, may be beneficial in the follow up of children who have treated clubfoot in isolated communities or lower resourced settings.

Visualization of Low-Level Gamma Radiation Sources Using a Low-Cost, High-Sensitivity, Omnidirectional Compton Camera.

We present experimental protocols for visualizing various low-level gamma radiation sources in the ambient environment. Experiments were conducted by using a low-cost, high-sensitivity, omnidirectional, gamma-ray imaging Compton camera. In the laboratory, the position of a sub-MeV gamma radiation source such as 137Cs can easily be monitored via omnidirectional gamma-ray imaging obtained by the Compton camera. In contrast, a stationary, wall-mounted dose rate monitor cannot always successfully monitor such a source. Furthermore, we successfully demonstrated the possibility of visualizing the radioactivity movement in the environment, for example, the movement of a patient injected with 18F-fluorodeoxyglucose (18F-FDG) in a nuclear medicine facility. In the Fukushima field, we easily obtained omnidirectional gamma-ray images concerned with the distribution on the ground of low-level radioactive contamination by radioactive cesium released by the Fukushima Daiichi nuclear power plant accident in 2011. We demonstrate clear advantages of using our procedure with this camera to visualize gamma-ray sources. Our protocols can further be used to discover low-level gamma radiation sources, in place of stationary dose rate monitors and/or portable survey meters used conventionally.

Random forest-based classsification and analysis of hemiplegia gait using low-cost depth cameras.

Hemiplegia is a form of paralysis that typically has the symptom of dysbasia. In current clinical rehabilitations, to measure the level of hemiplegia gaits, clinicians often conduct subject evaluations through observations, which is unreliable and inaccurate. The Microsoft Kinect sensor (MS Kinect) is a widely used, low-cost depth sensor that can be used to detect human behaviors in real time. The purpose of this study is to investigate the usage of the Kinect data for the classification and analysis of hemiplegia gait. We first acquire the gait data by using a MS Kinect and extract a set of gait features including the stride length, gait speed, left/right moving distances, and up/down moving distances. With the gait data of 60 subjects including 20 hemiplegia patients and 40 healthy subjects, we employ a random forest-based classification approach to analyze the importances of different gait features for hemiplegia classification. Thanks to the over-fitting avoidance nature of the random forest approach, we do not need to have a careful control over the percentage of patients in the training data. In our experiments, our approach obtained the averaged classification accuracy of 90.65% among all the combinations of the gait features, which substantially outperformed state-of-the-art methods. The best classification accuracy of our approach is 95.45%, which is superior than all existing methods. Additionally, our approach also correctly reveals the importance of different gait features for hemiplegia classification. Our random forest-based approach outperforms support vector machine-based method and the Bayesian-based method, and can effectively extract gait features of subjects with hemiplegia for the classification and analysis of hemiplegia. Graphical Abstract Random Forest based Classsification and Analysis of Hemiplegia Gait using Low-cost Depth Cameras. Left: Motion capture with MS Kinect; Top-right: Random Forest Classsification based on the extracted gait features; Bottom-right: Sensitivity and specificity evaluation of the proposed classification approach.

A method for measuring human body composition using digital images.

BACKGROUND/OBJECTIVES: Body mass index (BMI) is a proxy for obesity that is commonly used in spite of its limitation in estimating body fatness. Trained observers with repeated exposure to different body types can estimate body fat (BF) of individuals compared to criterion methods with reasonable accuracy. The purpose of this study was to develop and validate a computer algorithm to provide a valid estimate %BF using digital photographs. SUBJECTS/METHODS: Our sample included 97 children and 226 adults (age in years: 11.3±3.3; 38.1±11.6, respectively). Measured height and weight were used (BMI in kg/m2: 20.4±4.4; 28.7±6.6 for children and adults, respectively). Dual x-ray absorptiometry (DXA) was the criterion method. Body volume (BVPHOTO) and body shape (BSPHOTO) were derived from two digital images. Final support vector regression (SVR) models were trained using age, sex, race, BMI for % BFNOPHOTO, plus BVPHOTO and BSPHOTO for %BFPHOTO. Separate validation models were used to evaluate the learning algorithm in children and adults. The differences in correlations between %BFDXA, %BFNOPHOTO and %BFPHOTO were tested using the Fisher's Z-score transformation. RESULTS: Mean BFDXA and BFPHOTO were 27.0%±9.2 vs. 26.7%± 7.4 in children and 32.9± 10.4% vs. 32.8%±9.3 in adults. SVR models produced %BFPHOTO values strongly correlated with %BFDXA. Our final model produced correlations of rDP = 0.80 and rDP = 0.87 in children and adults, respectively for %BFPHOTO vs. %BFDXA. The correlation between %BFNOPHOTO and %BFDXA was moderate, yet statistically significant in both children rDB = 0.70; p <0.0001 and adults rDB = 0.86; p<0.0001. However, the correlations for rDP were statistically higher than rDB (%BFDXA vs. %BFNOPHOTO) in both children and adults (children: Z = 5.95, p<0.001; adults: Z = 3.27, p<0.0001). CONCLUSIONS: Our photographic method produced valid estimates of BF in both children and adults. Further research is needed to create norms for subgroups by sex, race/ethnicity, and mobility status.

Calibrating UVA reflectance photographs - standardisation using a low-cost method.

OBJECTIVE: While established methods for the calibration of visible light photographs are well defined, the use of these approaches in UVA reflectance photography is less well understood. A systematic, low-cost and simple method for the production of well-defined grey calibration standard targets for UVA reflectance photography, with a particular emphasis on low reflectivity surfaces, along with a comparison with standard visible light photographic standards is presented here. METHODS: Grey calibration standard targets suitable for use in the UVA region were produced, based on optimised methods from the literature. The standards were assessed using UV-Visible reflection spectroscopy, and visible and UVA light photography, and their behaviour compared with a commercially available visible light photographic calibration chart. RESULTS: Calibration standards with a relatively flat reflection response in the UVA region with a variety of reflectances between 2% and 35% were prepared. Imaging of the standards in both UV and visible light demonstrated the differences between these standards and the ones specifically designed for visible light photography. CONCLUSIONS: A low cost and simple method for the production of low reflectance UVA calibration targets, suitable for UVA reflectance photography has been described and tested against commercially available visual light calibration standards. These new UV suitable standards have potential for use in a wide range of applications such as forensics, biology and cosmetic science.

Age related prevalence of hand osteoarthritis diagnosed by photography (HOASCORE).

BACKGROUND: Hand photography has been used in a number of studies to determine the presence and severity of hand osteoarthritis (HOA). The aim of this study was to present age and gender specific prevalences of HOA diagnosed by this method. METHODS: Six thousand three hundred forty three photographs (from 3676 females and 2667 males aged 40-96) were scored for hand osteoarthritis by a 0-3 grade (0 = no evidence of OA, 1 = possible OA, 2 = definite OA and 3 = severe OA) for each of the three main sites, distal interphalangeal joints (DIP), proximal interphalangeal joints (PIP) and thumb base (CMC1). An aggregate score of 0-9 was thus obtained (HOASCORE) to reflect the severity of HOA in each case. RESULTS: DIP joints were most commonly affected, followed by the thumb base and the PIP joints. Having definite DIP joint OA starts at a younger age compared with the other two sites, and there is a marked female preponderance in the age groups from 55 to 69, but after 70 the gender differences are less marked and the prevalence is fairly stable. PIP joint prevalence also indicates a female preponderance from 60 to 79. Thumb base OA has a more marked female preponderance and a rising prevalence thoughout life. The prevalence of individuals with no evidence of photographic OA (HOASCORE = 0) drops from 88% to 57% between the age categories 40-49 and 50-54 and decreased to 33% in the 70-74 age group with a slower decline after that age. DIP and PIP prevalence were strongly associated with each other with an OR of 16.6(12.8-21.5),p < 0.001 of having definite OA at the other site. This was less marked for the thumb base with an OR of 2.2(1.8-2.7, p < 0.001), and 2.7(2.0-3.5, p < 0.001) of having definite DIP or PIP HOA respectively. CONCLUSIONS: The prevalence of hand OA in DIP, PIP and thumb base joints obtained by the photographic HOASCORE method is higher in women and increases after the age of fifty. These results are in line with those obtained by clinical examination and radiography. The advantage of the method lies in easy applicability and low cost.

Internet-based skin cancer screening using clinical images alone or in conjunction with dermoscopic images: A randomized teledermoscopy trial.

BACKGROUND: Teledermoscopy involves the use of dermoscopic images for remote consultation and decision-making in skin cancer screening. OBJECTIVE: We sought to analyze the potential benefits gained from the addition of dermoscopic images to an internet-based skin cancer screening system. METHODS: A randomized clinical trial assessed the diagnostic performance and cost-effectiveness of clinical teleconsultations (CTC) and clinical with dermoscopic teleconsultations. RESULTS: A total of 454 patients were enrolled in the trial (nCTC = 226, nclinical with dermoscopic teleconsultation = 228). Teledermoscopy improved sensitivity and specificity (92.86% and 96.24%, respectively) compared with CTC (86.57% and 72.33%, respectively). Correct decisions were made in 94.30% of patients through clinical with dermoscopic teleconsultations and in 79.20% in CTC (P < .001). The only variable associated with an increased likelihood of correct diagnosis was management using teledermoscopy (odds ratio 4.04; 95% confidence interval 2.02-8.09; P < .0001). The cost-effectiveness analysis showed teledermoscopy as the dominant strategy, with a lower cost-effectiveness ratio (65.13 vs 80.84). LIMITATIONS: Potentially, a limitation is the establishment of an experienced dermatologist as the gold standard for the in-person evaluation. CONCLUSIONS: The addition of dermoscopic images significantly improves the results of an internet-based skin cancer screening system, compared with screening systems based on clinical images alone.

Evidence for Telemedicine for Diabetic Retinal Disease.

According to current projections, the number of Americans with diabetes mellitus will increase from 27.8 million in 2007 to 60.7 million in 2030. With the increasing gap between demand for eye care and supply of ophthalmologists and optometrists, and the non-uniform distribution of eye care providers in US counties, barriers to eye examinations will likely increase. Telemedicine assessment of diabetic retinal disease through remote retinal imaging and diagnosis has the potential to meet these growing demands. To establish evidence for a telemedicine program as an effective modality for diabetic retinopathy (DR) assessment, the interpretation of teleretinal images should compare favorably with Early Treatment Diabetic Retinopathy Study film or digital photographs. We review the current evidence on the critical features and characteristics of ocular telehealth programs for DR in the following categories: image gradability, mydriasis, sensitivity and specificity, cost-effectiveness, long-term effectiveness, patient comfort and satisfaction, and improvement of patient related outcomes.

Histogram Planimetry Method for the Measurement of Irregular Wounds.

INTRODUCTION: Irregularly shaped wounds or flap borders usually require specified software or devices to measure their area and follow-up wound healing. In this study, an easy way of area measurement called histogram planimetry (HP) for wounds with irregular geometric shapes is defined and compared to conventional millimetric wound measurement. MATERIALS AND METHODS: Ten irregularly bordered geometric shapes were measured by 4 different individuals working as surgical assistants using both HP and manual millimetric measurement tools. The amount of time for each wound shape calculation as well as the measurements of the wound areas were noted. All measurements were compared for each method and between each individual using the Wilcoxon signed-rank test. RESULTS: There was no statistically significant difference between 2 measurement methods by means of measured areas; however, measurement time was significantly lower when the HP method was used. There also was no significant difference between the individuals' measurements and calculation times. These results indicated that HP is useful as a conventional millimetric square wound measurement technique with significantly lower measurement times. CONCLUSION: Due to the development of photo-editor software technologies, measurements in the surgical field have become more accurate and rapid than conventional manual methods without consuming the time and energy needed for other studies. A future study including comparisons between the presented method and complex computerized measurement methods, in terms of duration and accuracy, may provide additional supportive data for the authors' method.

Detection and quantification of subtle changes in red blood cell density using a cell phone.

Magnetic levitation has emerged as a technique that offers the ability to differentiate between cells with different densities. We have developed a magnetic levitation system for this purpose that distinguishes not only different cell types but also density differences in cells of the same type. This small-scale system suspends cells in a paramagnetic medium in a capillary placed between two rare earth magnets, and cells levitate to an equilibrium position determined solely by their density. Uniform reference beads of known density are used in conjunction with the cells as a means to quantify their levitation positions. In one implementation images of the levitating cells are acquired with a microscope, but here we also introduce a cell phone-based device that integrates the magnets, capillary, and a lens into a compact and portable unit that acquires images with the phone's camera. To demonstrate the effectiveness of magnetic levitation in cell density analysis we carried out levitation experiments using red blood cells with artificially altered densities, and also levitated those from donors. We observed that we can distinguish red blood cells of an anemic donor from those that are healthy. Since a plethora of disease states are characterized by changes in cell density magnetic cell levitation promises to be an effective tool in identifying and analyzing pathologic states. Furthermore, the low cost, portability, and ease of use of the cell phone-based system may potentially lead to its deployment in low-resource environments.

Diabetic retinopathy screening: the first telemedical approach in an Italian hospital.

PURPOSE: To assess the feasibility of a telemedical approach for diabetic retinopathy (DR) screening in the Italian population and to evaluate advantages/disadvantages in comparison to standard slit-lamp funduscopic examination (SFE). METHODS: This 1-year, Italian, single-center, observational study evaluated semiautomatic fundus photography (FP) DR screening, performed during routine type 2 diabetes (T2D) systemic visits and examined remotely. Adults with T2D underwent SFE and 3-field FP. The study was divided into 2 stages (stage 1 validated the screening procedure, stage 2 evaluated the screening impact on the clinical practice). Annual costs of SFE ± FP screening were compared. Patients completed a DR screening questionnaire. RESULTS: Of 1,281 T2D patients enrolled, 61% were male (mean age 65.69 ± 12.64 years). In stage 1, 71% and 15% of patients were considered nongradable when FP was performed before (BPD) versus after pupil dilation (APD). The FP specificity was higher with APD vs BPD (79% vs 25%); therefore, FP APD only was used for stage 2. Of 1,281 patients screened using FP APD, 240 (18.7%) had unreadable images; 64.3% did not have DR, and 17.0% were diagnosed with DR. There was a cost saving of €801.25 when screening was performed using FP. Overall, 98% of patients had a positive opinion of FP screening. CONCLUSIONS: The telemedicine approach provides a convenient, simple test that is well-received by patients and minimizes unnecessary referrals. Telemedicine may also reduce screening costs in our setting.

Two low-cost digital camera-based platforms for quantitative creatinine analysis in urine.

In clinical analysis creatinine is a routine biomarker for the assessment of renal and muscular dysfunctions. Although several techniques have been proposed for a fast and accurate quantification of creatinine in human serum or urine, most of them require expensive or complex apparatus, advanced sample preparation or skilled operators. To circumvent these issues, we propose two home-made platforms based on a CD Spectroscope (CDS) and Computer Screen Photo-assisted Technique (CSPT) for the rapid assessment of creatinine level in human urine. Both systems display a linear range (r(2) = 0.9967 and 0.9972, respectively) from 160 µmol L(-1) to 1.6 mmol L(-1) for standard creatinine solutions (n = 15) with respective detection limits of 89 µmol L(-1) and 111 µmol L(-1). Good repeatability was observed for intra-day (1.7-2.9%) and inter-day (3.6-6.5%) measurements evaluated on three consecutive days. The performance of CDS and CSPT was also validated in real human urine samples (n = 26) using capillary electrophoresis data as reference. Corresponding Partial Least-Squares (PLS) regression models provided for mean relative errors below 10% in creatinine quantification.

Tele-ophthalmology screening for proliferative diabetic retinopathy in urban primary care offices: an economic analysis.

BACKGROUND AND OBJECTIVE: To determine whether tele-ophthalmology screening for proliferative diabetic retinopathy (PDR) can be cost-saving. PATIENTS AND METHODS: Adults with diabetes presenting for routine medical care underwent non-mydriatic fundus photography with remote grading. Direct medical costs were estimated using the Medicare fee schedule in the base case, with Medicaid and commercial insurance rates used for low and high values, respectively. One-way and probabilistic sensitivity analyses were performed. RESULTS: Of 99 participants, at least mild retinopathy was found in 24 (24.2%). Urgent consultation was recommended for eight participants (8.1%) for possible vision-threatening diabetic retinopathy, including two participants (three eyes) with PDR. In the base case, screening saved $36 per patient. A Monte Carlo simulation indicated that screening saved a median of $48 per patient. CONCLUSION: A substantial burden of diabetic retinopathy was identified, most of which was undiagnosed. In a closed system, tele-ophthalmology screening for PDR is likely to be cost-saving across the range of scenarios explored.

Improving the cost-effectiveness of photographic screening for diabetic macular oedema: a prospective, multi-centre, UK study.

BACKGROUND/AIMS: Retinal screening programmes in England and Scotland have similar photographic grading schemes for background (non-proliferative) and proliferative diabetic retinopathy, but diverge over maculopathy. We looked for the most cost-effective method of identifying diabetic macular oedema from retinal photographs including the role of automated grading and optical coherence tomography, a technology that directly visualises oedema. METHODS: Patients from seven UK centres were recruited. The following features in at least one eye were required for enrolment: microaneurysms/dot haemorrhages or blot haemorrhages within one disc diameter, or exudates within one or two disc diameters of the centre of the macula. Subjects had optical coherence tomography and digital photography. Manual and automated grading schemes were evaluated. Costs and QALYs were modelled using microsimulation techniques. RESULTS: 3540 patients were recruited, 3170 were analysed. For diabetic macular oedema, England's scheme had a sensitivity of 72.6% and specificity of 66.8%; Scotland's had a sensitivity of 59.5% and specificity of 79.0%. When applying a ceiling ratio of £30,000 per quality adjusted life years (QALY) gained, Scotland's scheme was preferred. Assuming automated grading could be implemented without increasing grading costs, automation produced a greater number of QALYS for a lower cost than England's scheme, but was not cost effective, at the study's operating point, compared with Scotland's. The addition of optical coherence tomography, to each scheme, resulted in cost savings without reducing health benefits. CONCLUSIONS: Retinal screening programmes in the UK should reconsider the screening pathway to make best use of existing and new technologies.