EFFORTH: EFFiciency and EFFectiveness in ORTHopedics

status: Published onlin

Towards automatic detection of movement during sleep in pediatric patients with epilepsy by means of video recordings and the optical flow algorithm

The detection and analysis of epileptic seizures is typically done by video-electroencephalogram monitoring. Although it is considered as the Golden Standard, it has disadvantages: the electroencephalogram electrodes are uncomfortable to wear for a longer period of time and hospitalization is often required. The aim of our work is to investigate whether the optical flow algorithm applied to video recordings can be used to detect movement during sleep in pediatric patients with epilepsy. The optical flow algorithm allocates intensities to pixels proportional to their involvement in movement of an object in a scene. The average of the 0.06% highest of these intensities was plotted as a function of time R(t). As dataset we used simulated video recordings (640×480 30fps) consisting of normal sleep movement and seizure-like movement. We investigated R(t) as a function of the acquisition parameters (such as spatial resolution, frame rate and compression) and environment parameters (such as illumination and camera viewpoint). We found that we still could make a distinction between movement and non-movement, when we spatially downsampled to 320×240. Furthermore we found that we could reduce the frame rate to 10 frames per second). The reduction in spatial and temporal resolution eases the computational load of the algorithm which puts future real-time applications in reach. MPEG-compression and reduced illumination increased R(t) for non-movement frames. Camera positions where in-plain movement is larger than out-of-plain movement yield a larger R(t) than vice versa. From our findings above we extracted the optimal acquisition parameters which guaranty clear distinction between movement (high R(t)) and non-movement (low R(t)). © 2009 Springer Berlin Heidelberg.status: publishe

Evaluation of applying fused deposition modeling to 3D print lower limb orthotics in West-Africa: preliminary results of the Imp&Acte3D project

status: accepte

A prospective comparative study between a cooling device and manual cooling after total knee arthroplasty

Background Studies have shown that the use of cryotherapy after a total knee arthroplasty can have beneficial effect on blood loss, pain and medication usage. In this study, the effect of the applied cryotherapy procedure is investigated.Methods 52 patients underwent a total knee arthroplasty. The test group received continuous cooling, whereas the control group received manual conventional cooling with ice dressing. The knee circumference and range of motion, medication use, satisfaction and pain were investigated.Results There is no statistical significant difference in pain and medication usage. A significant difference is observed in the swelling of the knee on the first postoperative day, the range of motion on the 7th, 10th, 11th and 12th postoperative day, and the satisfaction rate.Conclusion This study shows that continuous cooling has a positive effect on the swelling and range of motion of the knee, and on the satisfaction of the treatment

Detection of Nocturnal Epileptic Seizures of Pediatric Patients Using Accelerometers

status: publishe

Ambulatory monitoring of physical activity based on knee flexion/extension measured by inductive sensor technology

We developed a knee brace to measure the knee angle and implicitly the flexion/extension (f/e) of the knee joint during daily activities. The goal of this study is to classify and validate a limited set of physical activities on ten young healthy subjects based on knee f/e. Physical activities included in this study are walking, ascending and descending of stairs, and fast locomotion (such as jogging, running, and sprinting) at self-selected speeds. The knee brace includes 2 accelerometers for static measurements and calibration and an inductive sensor for dynamic measurements.Aswe focus on physical activities, the inductive sensorwill provide the required information on knee f/e. In this study, the subjects traversed a predefined track which consisted of indoor paths, outdoor paths, and obstacles. The activity classification algorithm based on peak detection in the knee f/e angle resulted in a detection rate of 95.9% for walking, 90.3% for ascending stairs, 78.3% for descending stairs, and 82.2% for fast locomotion.We conclude that we developed a measurement device which allows long-termand ambulatorymonitoring. Furthermore, it is possible to predict the aforementioned activities with an acceptable performance.status: publishe

Screening Of Foot-related Musculoskeletal Problems In Non-sedentary Employees, How Can We Improve The Quantification?

status: publishe

Evaluation of the influence of cyclic loading on a laser sintered transtibial prosthetic socket using Digital Image Correlation (DIC)

People with a transtibial amputation worldwide rely on their prosthetic socket to regain their mobility. Patient comfort is largely affected by the weight and strength of these prosthetic sockets. The use of additive manufacturing could give the prosthetist a range of new design possibilities when designing a prosthetic socket. These new design possibilities can in turn lead to improved socket designs and more comfortable prosthetic sockets. This new way of designing and producing prosthetic sockets radically differs from the manual traditional production process. This makes it difficult for prosthetists to understand how all these new design possibilities influence the mechanical properties of the additive manufactured prosthetic socket. Therefore there is a growing need for a method to evaluate the strength and stiffness of newly developed socket designs.We propose a method to evaluate the strength and stiffness of prosthetic sockets. A robotic gait simulator is used to apply realistic kinetics of amputee gait to the tested socket. A Digital Image Correlation (DIC) system is then used to measure the deformation of a prosthetic socket under different loading conditions. This way it is possible to check if plastic deformation will occur in the designed transtibial socket. Furthermore it is possible to assess the effect of cyclic loading on the 3D printed socket.To illustrate the proposed method, a transtibial prosthetic socket was designed using CAD software and produced with laser sintering PA12. DIC measurements were performed on this transtibial socket both before and after it was subjected to a cyclic load of 1 million cycles (mimicking realistic amputee gait).status: accepte