A feasibility study of depth image based intent recognition for lower limb prostheses

This paper presents our preliminary work on a depth camera based intent recognition system intended for future use in robotic prosthetic legs. The approach infers the activity mode of the subject for standing, walking, running, stair ascent and stair descent modes only using data from the depth camera. Depth difference images are also used to increase the performance of the approach by discriminating between static and dynamic instances. After confidence map based filtering, simple features such as mean, maximum, minimum and standard deviation are extracted from rectangular regions of the frames. A support vector machine with a cubic kernel is used for the classification task. The classification results are post-processed by a voting filter to increase the robustness of activity mode recognition. Experiments conducted with a healthy subject donning the depth camera to his lower leg showed the efficacy of the approach. Specifically, the depth camera based recognition system was able to identify 28 activity mode transitions successfully. The only case of incorrect mode switching was an intended run to stand transition, where an intermediate transition from run to walk was recognized before transitioning to the intended standing mode.

Effects of carotid baroreceptor stimulation on retinal arteriole remodeling evaluated with adaptive optics camera in resistant hypertensive patients

BACKGROUND AND AIM

Baroreceptor activation therapy (BAT) leads to a decrease in blood pressure (BP) in patients affected by resistant hypertension (RH) by reducing sympathetic outflow. This study aimed at evaluating the effects of BAT on RH patients' retinal arteriolar microvasculature, a territory devoid of adrenergic innervation.

PATIENTS AND METHODS

Five patients defined as affected by RH after excluding secondary causes of hypertension and based on number of antihypertensive treatments, underwent the implantation of Barostim™ neo™. Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) were assessed by office and 24-hours ambulatory BP monitoring (ABPM). Adaptive Optics Camera RTX1^® (ImagineEye, Orsay, France) was used to measure wall thickness (WT), internal diameter (ID), wall cross-sectional area (WCSA) and wall-to-lumen ratio (WLR). A cohort of 21 not-controlled hypertensive patients matched for age, gender and follow-up time, undergoing standard-antihypertensive therapy changes, was selected as a control group. SBP and DBP were assessed by office and home BP monitoring (HBPM). Evaluations were performed at baseline and after 6 months mean follow-up.

RESULTS

Office SBP decreased by 9.7±12.3% and 29.7±12.4% in standard-therapy and BAT group respectively, while office DBP decreased by 7.6±17.4% and 14.8±15.7%. Concerning ABPM/HBPM, a mean reduction of both SBP and DBP of 7.9±11% was observed for the standard-therapy while a reduction of 15.8±10.5% and 15.8%±5.3% was observed for SBP and DBP respectively in BAT group. While in the standard-therapy group a significant reduction in WLR (-5.9%) due to both ID increase (+2.3%) and WT reduction (-5.7%) was observed, without changes in WCSA (-0.3%), RH patients had a significant reduction in WCSA (-12.1%), due to a trend in both WT and ID reduction (-6.5% and -1.7% respectively), without significant changes in WLR (-2%).

CONCLUSION

While a reverse eutrophic remodeling was observed in patients undergoing a standard-antihypertensive treatment, hypotrophic changes were found in RH patients undergoing BAT. Despite the lack of adrenergic receptors on retinal vessels, chronic baroreflex stimulation may exert an effect on retinal microvasculature in RH patients by more systemic than local mechanisms.

Portable equipment for taking dramatic sun-damage revealing photos at skin cancer prevention outreach events

In recent years, appearance-based interventions have gained popularity as a means to improve public awareness about skin cancer and sun protective behaviors. Although numerous reports discuss the use of ultraviolet (UV) camera devices for this purpose,studies on the use of portable imaging devices in community outreach events do not presently exist. In this report, we discuss how we successfully utilize portable imaging devices at community outreach events. We also discuss the advantages and disadvantages of our portable devices in comparison to traditional UV cameras. Portable imaging devices are easy to use and have allowed us to increase our involvement in community outreach events targeting a wide range of participants.

Camera trap arrays improve detection probability of wildlife: Investigating study design considerations using an empirical dataset

Camera trapping is a standard tool in ecological research and wildlife conservation. Study designs, particularly for small-bodied or cryptic wildlife species often attempt to boost low detection probabilities by using non-random camera placement or baited cameras, which may bias data, or incorrectly estimate detection and occupancy. We investigated the ability of non-baited, multi-camera arrays to increase detection probabilities of wildlife. Study design components were evaluated for their influence on wildlife detectability by iteratively parsing an empirical dataset (1) by different sizes of camera arrays deployed (1–10 cameras), and (2) by total season length (1–365 days). Four species from our dataset that represented a range of body sizes and differing degrees of presumed detectability based on life history traits were investigated: white-tailed deer (Odocoileus virginianus), bobcat (Lynx rufus), raccoon (Procyon lotor), and Virginia opossum (Didelphis virginiana). For all species, increasing from a single camera to a multi-camera array significantly improved detection probability across the range of season lengths and number of study sites evaluated. The use of a two camera array increased survey detection an average of 80% (range 40–128%) from the detection probability of a single camera across the four species. Species that were detected infrequently benefited most from a multiple-camera array, where the addition of up to eight cameras produced significant increases in detectability. However, for species detected at high frequencies, single cameras produced a season-long (i.e, the length of time over which cameras are deployed and actively monitored) detectability greater than 0.75. These results highlight the need for researchers to be critical about camera trap study designs based on their intended target species, as detectability for each focal species responded differently to array size and season length. We suggest that researchers a priori identify target species for which inference will be made, and then design camera trapping studies around the most difficult to detect of those species.

Design and Evaluation of a Training Protocol for a Photographic Method of Visual Estimation of Fruit and Vegetable Intake among Kindergarten Through Second-Grade Students

OBJECTIVE

To design a replicable training protocol for visual estimation of fruit and vegetable (FV) intake of kindergarten through second-grade students through digital photography of lunch trays that results in reliable data for FV served and consumed.

METHODS

Protocol development through literature and researcher input was followed by 3 laboratory-based trainings of 3 trainees. Lunchroom data collection sessions were done at 2 elementary schools for kindergarten through second-graders. Intraclass correlation coefficients (ICCs) were used.

RESULTS

By training 3, ICC was substantial for amount of FV served and consumed (0.86 and 0.95, respectively; P < .05). The ICC was moderate for percentage of fruits consumed (0.67; P = .06). In-school estimates for ICCs were all significant for amounts served at school 1 and percentage of FV consumed at both schools.

CONCLUSIONS AND IMPLICATIONS

The protocol resulted in reliable estimation of combined FV served and consumed using digital photography. The ability to estimate FV intake accurately will benefit intervention development and evaluation.

Microfluidic device enabled quantitative time-lapse microscopic-photography for phenotyping vegetative and reproductive phases in Fusarium virguliforme, which is pathogenic to soybean

Time-lapse microscopic-photography allows in-depth phenotyping of microorganisms. Here we report development of such a system using a microfluidic device, generated from polydimethylsiloxane and glass slide, placed on a motorized stage of a microscope for conducting time-lapse microphotography of multiple observations in 20 channels simultaneously. We have demonstrated the utility of the device in studying growth, germination and sporulation in Fusarium virguliforme that causes sudden death syndrome in soybean. To measure the growth differences, we developed a polyamine oxidase fvpo1 mutant in this fungus that fails to grow in minimal medium containing polyamines as the sole nitrogen source. Using this system, we demonstrated that the conidiospores of the pathogen take an average of five hours to germinate. During sporulation, it takes an average of 10.5 h for a conidiospore to mature and get detached from its conidiophore for the first time. Conidiospores are developed in a single conidiophore one after another. The microfluidic device enabled quantitative time-lapse microphotography reported here should be suitable for screening compounds, peptides, micro-organisms to identify fungitoxic or antimicrobial agents for controlling serious plant pathogens. The device could also be applied in identifying suitable target genes for host-induced gene silencing in pathogens for generating novel disease resistance in crop plants.

Video Movement Analysis Using Smartphones (ViMAS): A Pilot Study

The use of smartphones in clinical practice is steadily increasing with the availability of low cost/freely available "apps" that could be used to assess human gait. The primary aim of this manuscript is to test the concurrent validity of kinematic measures recorded by a smartphone application in comparison to a 3D motion capture system in the sagittal plane. The secondary aim was to develop a protocol for clinicians on the set up of the smartphone camera for video movement analysis. The sagittal plane knee angle was measured during heel strike and toe off events using the smart phone app and a 3D motion-capture system in 32 healthy subjects. Three trials were performed at near (2-m) and far (4-m) smartphone camera distances. The order of the distances was randomized. Regression analysis was performed to estimate the height of the camera based on either the subject's height or leg length. Absolute measurement errors were least during toe off (3.12 ± 5.44 degrees) compared to heel strike (5.81 ± 5.26 degrees). There were significant (p < 0.05) but moderate agreements between the application and 3D motion capture measures of knee angles. There were also no significant (p > 0.05) differences between the absolute measurement errors between the two camera positions. The measurement errors averaged between 3 - 5 degrees during toe off and heel strike events of the gait cycle. The use of smartphone apps can be a useful tool in the clinic for performing gait or human movement analysis. Further studies are needed to establish the accuracy in measuring movements of the upper extremity and trunk.

Rate of Strabismus Detection on Digital Photographs Increases by Using Off-center Near Target

PURPOSE

To increase the detection rate of strabismus on digital photographs, with the ultimate aim of developing a new automated strabismus detection algorithm.

METHODS

In this prospective case series, the authors acquired digital face photographs of 409 children with manifest or latent strabismus, using a 14-million-pixel camera with CCD image sensor. Of the last 52 enrolled, 34 image sets were selected for this study: 29 with manifest and 5 with latent strabismus. Images were taken at a distance of 40 to 70 cm in primary position, with the camera lens as the fixation target and in slight off-center fixation, and using a novel target of small light-emitting diodes mounted onto the camera case. The location of the corneal light reflection was manually calculated in relation to the center of the pupil in both eyes and ocular deviation as the difference in corneal light reflection location between the two eyes. In orthotropia, the expected deviation is zero.

RESULTS

In children with phorias, the mean corneal light reflection location difference between the eyes was -0.10 ± 0.14 mm in primary position and -2.02 ± 0.39 mm in off-center fixation. Using a threshold of ±0.5 mm on either side of zero for central and of 2 mm for off-center fixation, sensitivity to detect strabismus increased from 65.6% in central to 79.3% in off-center fixation, respectively. The calculation of specificity will require inclusion of a population of individuals without strabismus.

CONCLUSIONS

Off-center fixation onto a near target ensures that participants are actively looking at the target and may increase accommodative effort, thereby increasing the detection rate of strabismus. [J Pediatr Ophthalmol Strabismus. 2017;54(2):90-96.].

Comprehensive measurement of UVB-induced non-melanoma skin cancer burden in mice using photographic images as a substitute for the caliper method

The vernier caliper has been used as a gold standard to measure the length, width and height of skin tumors to calculate their total area and volume. It is a simple method for collecting data on a few tumors at a time, but becomes tedious, time-consuming and stressful for the animals and the operator when used for measuring multiple tumors in a large number of animals in protocols such as UVB-induced non-melanoma skin cancer (NMSC) in SKH-1 mice. Here, we show that photographic images of these mice taken within a few minutes under optimized conditions can be subjected to computerized analyses to determine tumor volume and area as accurately and precisely as the caliper method. Unlike the caliper method, the photographic method also records the incidence and multiplicity of tumors, thus permitting comprehensive measurement of tumor burden in the animal. The simplicity and ease of this method will permit more frequent monitoring of tumor burden in long protocols, resulting in the creation of additional data about dynamic changes in progression of cancer or the efficacy of therapeutic intervention. The photographic method can broadly substitute the caliper method for quantifying other skin pathologies.

Vehicle autonomous localization in local area of coal mine tunnel based on vision sensors and ultrasonic sensors

This paper presents a vehicle autonomous localization method in local area of coal mine tunnel based on vision sensors and ultrasonic sensors. Barcode tags are deployed in pairs on both sides of the tunnel walls at certain intervals as artificial landmarks. The barcode coding is designed based on UPC-A code. The global coordinates of the upper left inner corner point of the feature frame of each barcode tag deployed in the tunnel are uniquely represented by the barcode. Two on-board vision sensors are used to recognize each pair of barcode tags on both sides of the tunnel walls. The distance between the upper left inner corner point of the feature frame of each barcode tag and the vehicle center point can be determined by using a visual distance projection model. The on-board ultrasonic sensors are used to measure the distance from the vehicle center point to the left side of the tunnel walls. Once the spatial geometric relationship between the barcode tags and the vehicle center point is established, the 3D coordinates of the vehicle center point in the tunnel’s global coordinate system can be calculated. Experiments on a straight corridor and an underground tunnel have shown that the proposed vehicle autonomous localization method is not only able to quickly recognize the barcode tags affixed to the tunnel walls, but also has relatively small average localization errors in the vehicle center point’s plane and vertical coordinates to meet autonomous unmanned vehicle positioning requirements in local area of coal mine tunnel.

A reduced-dimensionality approach to uncovering dyadic modes of body motion in conversations

Face-to-face conversations are central to human communication and a fascinating example of joint action. Beyond verbal content, one of the primary ways in which information is conveyed in conversations is body language. Body motion in natural conversations has been difficult to study precisely due to the large number of coordinates at play. There is need for fresh approaches to analyze and understand the data, in order to ask whether dyads show basic building blocks of coupled motion. Here we present a method for analyzing body motion during joint action using depth-sensing cameras, and use it to analyze a sample of scientific conversations. Our method consists of three steps: defining modes of body motion of individual participants, defining dyadic modes made of combinations of these individual modes, and lastly defining motion motifs as dyadic modes that occur significantly more often than expected given the single-person motion statistics. As a proof-of-concept, we analyze the motion of 12 dyads of scientists measured using two Microsoft Kinect cameras. In our sample, we find that out of many possible modes, only two were motion motifs: synchronized parallel torso motion in which the participants swayed from side to side in sync, and still segments where neither person moved. We find evidence of dyad individuality in the use of motion modes. For a randomly selected subset of 5 dyads, this individuality was maintained for at least 6 months. The present approach to simplify complex motion data and to define motion motifs may be used to understand other joint tasks and interactions. The analysis tools developed here and the motion dataset are publicly available.

Feasibility of Using Microsoft Kinect to Assess Upper Limb Movement in Type III Spinal Muscular Atrophy Patients

Although functional rating scales are being used increasingly as primary outcome measures in spinal muscular atrophy (SMA), sensitive and objective assessment of early-stage disease progression and drug efficacy remains challenging. We have developed a game based on the Microsoft Kinect sensor, specifically designed to measure active upper limb movement. An explorative study was conducted to determine the feasibility of this new tool in 18 ambulant SMA type III patients and 19 age- and gender-matched healthy controls. Upper limb movement was analysed elaborately through derived features such as elbow flexion and extension angles, arm lifting angle, velocity and acceleration. No significant differences were found in the active range of motion between ambulant SMA type III patients and controls. Hand velocity was found to be different but further validation is necessary. This study presents an important step in the process of designing and handling digital biomarkers as complementary outcome measures for clinical trials.

Neuro-Analogical Gate Tuning of Trajectory Data Fusion for a Mecanum-Wheeled Special Needs Chair

Trajectory tracking of mobile wheeled chairs using internal shaft encoder and inertia measurement unit(IMU), exhibits several complications and accumulated errors in the tracking process due to wheel slippage, offset drift and integration approximations. These errors can be realized when comparing localization results from such sensors with a camera tracking system. In long trajectory tracking, such errors can accumulate and result in significant deviations which make data from these sensors unreliable for tracking. Meanwhile the utilization of an external camera tracking system is not always a feasible solution depending on the implementation environment. This paper presents a novel sensor fusion method that combines the measurements of internal sensors to accurately predict the location of the wheeled chair in an environment. The method introduces a new analogical OR gate structured with tuned parameters using multi-layer feedforward neural network denoted as “Neuro-Analogical Gate” (NAG). The resulting system minimize any deviation error caused by the sensors, thus accurately tracking the wheeled chair location without the requirement of an external camera tracking system. The fusion methodology has been tested with a prototype Mecanum wheel-based chair, and significant improvement over tracking response, error and performance has been observed.

Safety effectiveness and crash cost benefit of red light cameras in Missouri

OBJECTIVE

Red light cameras (RLCs) have generated heated discussions over issues of safety effectiveness, revenue generation, and procedural due process. This study focuses on the safety evaluation of RLCs in Missouri, including the economic valuation of safety benefits. The publication of the national Highway Safety Manual (HSM; American Association of State Highway and Transportation Officials) in 2010 produced statistical safety models for intersections and spurred the calibration of these models to local conditions.

METHODS

This study adds to existing knowledge by applying the latest statistical methodology presented in the HSM and more current data. Driver behavior constantly changes due in part to driving conditions and the use of technology. The safety and economic benefit evaluation was performed using the empirical Bayes method, which accounts for regression to the mean bias. For the economic benefit evaluation, the KABCO crash severity scale and crash cost estimates were used. A total of 24 4-leg urban intersections were randomly selected from a master list of RLCs in Missouri from 2006 to 2011. Additionally, 35 comparable nontreated intersections were selected for the analysis.

RESULTS AND CONCLUSIONS

The implementation of RLCs reduced overall angle crashes by 11.6%, whereas rear-end crashes increased by 16.5%. The net economic crash cost benefit of the implementation of RLCs was $35,269 per site per year in 2001 dollars (approximately $47,000 in 2015 dollars). Thus, RLCs produced a sizable net positive safety benefit that is consistent with previous statistical studies.

Screening for Diabetic Retinopathy Using a Portable, Noncontact, Nonmydriatic Handheld Retinal Camera

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of low vision and blindness. We evaluated the feasibility of using a handheld, noncontact digital retinal camera, Pictor, to obtain retinal images in dilated and undilated eyes for DR screening. We also evaluated the accuracy of ophthalmologists with different levels of training/experience in grading these images to identify eyes with vision-threatening DR.

METHODS

A prospective study of diabetic adults scheduled to have dilated eye exams at Duke Eye Center from January to May 2014 was conducted. An imager acquired retinal images pre- and postdilation with Pictor and selected 1 pre- and 1 postdilation image per eye. Five masked ophthalmologists graded images for gradability (based on image focus and centration) and the presence of no, mild, moderate, or severe nonproliferative DR (NPDR) or proliferative DR (PDR). Referable disease was defined as moderate or severe NPDR or PDR on image grading. We evaluated feasibility based on the graders' evaluation of image gradability. We evaluated accuracy of identifying vision-threatening disease (severe NPDR or PDR documented on dilated clinical examination) based on the graders' sensitivity and specificity of grading referable disease.

RESULTS

Images were gradable in 86-94% of predilation and 94-97% of postdilation photos. Compared to the dilated clinical exam, overall sensitivity for identifying vision-threatening DR was 64-88% and specificity was 71-90%.

CONCLUSIONS

Pictor can capture retinal images of sufficient quality to screen for DR with and without dilation. Single retinal images obtained using Pictor can identify eyes with vision-threatening DR with high sensitivity and acceptable specificity compared to clinical exam.

Can Commercially Available Handheld Retinal Cameras Effectively Screen Diabetic Retinopathy?

Organizations that care for people with diabetes have increasingly adopted telemedicine-based diabetic retinopathy screening (TMDRS) as a way to increase adherence to recommended retinal exams. Recently, handheld retinal cameras have emerged as a low-cost, lightweight alternative to traditional bulky tabletop retinal cameras. Few published clinical trials have been performed on handheld retinal cameras. Peer-reviewed articles about commercially available handheld retinal cameras have concluded that they are a usable alternative for TMDRS, however, the clinical results presented in these articles do not meet criteria published by the United Kingdom Diabetic Eye Screening Programme and the American Academy of Ophthalmology. The future will likely remedy the shortcomings of currently available handheld retinal cameras, and will create more opportunities for preventing diabetic blindness.

Heterogeneous treatment effects of speed cameras on road safety

This paper analyses how the effects of fixed speed cameras on road casualties vary across sites with different characteristics and evaluates the criteria for selecting camera sites. A total of 771 camera sites and 4787 potential control sites are observed for a period of 9 years across England. Site characteristics such as road class, crash history and site length are combined into a single index, referred to as a propensity score. We first estimate the average effect at each camera site using propensity score matching. The effects are then estimated as a function of propensity scores using local polynomial regression. The results show that the reduction in personal injury collisions ranges from 10% to 40% whilst the average effect is 25.9%, indicating that the effects of speed cameras are not uniform across camera sites and are dependent on site characteristics, as measured by propensity scores. We further evaluate the criteria for selecting camera sites in the UK by comparing the effects at camera sites meeting and not meeting the criteria. The results show that camera sites which meet the criteria perform better in reducing casualties, implying the current site selection criteria are rational.

A Novel Camera Calibration Method Based on Polar Coordinate

A novel calibration method based on polar coordinate is proposed. The world coordinates are expressed in the form of polar coordinates, which are converted to world coordinates in the calibration process. In the beginning, the calibration points are obtained in polar coordinates. By transformation between polar coordinates and rectangular coordinates, the points turn into form of rectangular coordinates. Then, the points are matched with the corresponding image coordinates. At last, the parameters are obtained by objective function optimization. By the proposed method, the relationships between objects and cameras are expressed in polar coordinates easily. It is suitable for multi-camera calibration. Cameras can be calibrated with fewer points. The calibration images can be positioned according to the location of cameras. The experiment results demonstrate that the proposed method is an efficient calibration method. By the method, cameras are calibrated conveniently with high accuracy.

Accuracy of machine learning classifiers using bilateral data from a Scheimpflug camera for identifying eyes with preclinical signs of keratoconus

PURPOSE

To describe the topographic and tomographic characteristics of normal fellow eyes of unilateral keratoconus cases and to evaluate the accuracy of machine learning classifiers in discriminating healthy corneas from the normal fellow corneas.

SETTING

Department of Ophthalmology, Semmelweis University, Budapest, Hungary.

DESIGN

Retrospective case-control study.

METHODS

Patients with bilateral keratoconus (keratoconus group), clinically and according to the keratoconus indices of the Pentacam HR Scheimpflug camera; normal fellow eyes of patients with unilateral keratoconus (fellow-eye group); and eyes of refractive surgery candidates (control group) were compared. Tomographic data, topographic data, and keratoconus indices were measured in both eyes using the Scheimpflug camera. Receiver operating characteristic (ROC) analysis was used to assess the performance of automated classifiers trained on bilateral data as well as individual parameters to discriminate fellow eyes of patients with keratoconus from control eyes.

RESULTS

Keratometry, elevation, and keratoconus indices values were significantly higher and pachymetry values were significantly lower in keratoconus eyes than in fellow eyes of unilateral keratoconus cases (P < .001). These fellow eyes had significantly higher keratometry, elevation, and keratoconus index values and significantly lower pachymetry values than control eyes (P < .001). Automated classifiers trained on bilateral data of index of height decentration had higher accuracy than the unilateral single parameter in discriminating fellow eyes of patients with keratoconus from control eyes (area under ROC 0.96 versus 0.88).

CONCLUSION

Automatic classifiers trained on bilateral data were better than single parameters in discriminating fellow eyes of patients with unilateral keratoconus with preclinical signs of keratoconus from normal eyes.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

The case for body cameras in a healthcare environment

The author, an experienced investigator and trainer, makes the case in this article for the use of body cameras by healthcare security and non-security personnel to confirm that they acted within policy, law, and regulatory guidelines during an incident. The many benefits of such cameras in enhancing training of healthcare personnel are also described.

Estimating 3D tilt from local image cues in natural scenes

Estimating three-dimensional (3D) surface orientation (slant and tilt) is an important first step toward estimating 3D shape. Here, we examine how three local image cues from the same location (disparity gradient, luminance gradient, and dominant texture orientation) should be combined to estimate 3D tilt in natural scenes. We collected a database of natural stereoscopic images with precisely co-registered range images that provide the ground-truth distance at each pixel location. We then analyzed the relationship between ground-truth tilt and image cue values. Our analysis is free of assumptions about the joint probability distributions and yields the Bayes optimal estimates of tilt, given the cue values. Rich results emerge: (a) typical tilt estimates are only moderately accurate and strongly influenced by the cardinal bias in the prior probability distribution; (b) when cue values are similar, or when slant is greater than 40°, estimates are substantially more accurate; (c) when luminance and texture cues agree, they often veto the disparity cue, and when they disagree, they have little effect; and (d) simplifying assumptions common in the cue combination literature is often justified for estimating tilt in natural scenes. The fact that tilt estimates are typically not very accurate is consistent with subjective impressions from viewing small patches of natural scene. The fact that estimates are substantially more accurate for a subset of image locations is also consistent with subjective impressions and with the hypothesis that perceived surface orientation, at more global scales, is achieved by interpolation or extrapolation from estimates at key locations.

Image Montaging for Creating a Virtual Pathology Slide: An Innovative and Economical Tool to Obtain a Whole Slide Image

Background. Microscopes are omnipresent throughout the field of biological research. With microscopes one can see in detail what is going on at the cellular level in tissues. Though it is a ubiquitous tool, the limitation is that with high magnification there is a small field of view. It is often advantageous to see an entire sample at high magnification. Over the years technological advancements in optics have helped to provide solutions to this limitation of microscopes by creating the so-called dedicated "slide scanners" which can provide a "whole slide digital image." These scanners can provide seamless, large-field-of-view, high resolution image of entire tissue section. The only disadvantage of such complete slide imaging system is its outrageous cost, thereby hindering their practical use by most laboratories, especially in developing and low resource countries. Methods. In a quest for their substitute, we tried commonly used image editing software Adobe Photoshop along with a basic image capturing device attached to a trinocular microscope to create a digital pathology slide. Results. The seamless image created using Adobe Photoshop maintained its diagnostic quality. Conclusion. With time and effort photomicrographs obtained from a basic camera-microscope set up can be combined and merged in Adobe Photoshop to create a whole slide digital image of practically usable quality at a negligible cost.

Lesson learned from the application of intersection safety devices in Edmonton

The City of Edmonton began its intersection safety device (ISD) program in 2009 with the installation of 50 cameras throughout the city. The ISDs are approach-specific and combine automated enforcement of red-light running and speed violations during the red and green phases of the intersection control. The goal of this study is to evaluate the safety performance of ISDs within the city of Edmonton, Canada and to identify factors that can lead to successful selection of future ISD sites. A before-and-after Empirical Bayes (EB) method is used to account for regression-to-the-mean and other confounding factors. A safety performance function and yearly calibration factors are developed using data from a set of reference intersections within Edmonton. The before-and-after analysis is applied at the overall intersection level and for each approach of the ISD intersections. The results showed significant reductions that ranged from 12% to 25% for total collisions, and from 33% to 43% for angle collisions. No significant reduction was observed for severe collisions at the intersection level, however significant reductions were found at the approach level at locations with a relatively higher collision history. The impact of site selection criteria on collision reduction was also evaluated. Greater reductions were found at sites with a higher collision frequency. Additionally, the impact of intersection characteristics on collision reduction was investigated. Speed limits, presence of separated right turn lane and the number of lanes were found to impact ISD collision reduction.

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.