Analysis of healthy sitting behavior: Interface pressure distribution and subcutaneous tissue oxygenation

Pressure ulcers are a large problem in individuals who use a wheelchair for their mobility and have limited trunk stability and motor function. Because no relation between interface pressure and pressure ulcer development has been established and no clinical threshold for pressure ulcer development can be given, looking at the sitting behavior of nondisabled individuals is important. Nondisabled individuals do not develop pressure ulcers because they continuously shift posture. We analyzed the sitting behavior of 25 nondisabled male subjects by using a combination of interface pressure measurement and subcutaneous tissue oxygenation measurement by means of the Oxygen to See. These subjects shifted posture on average 7.8 +/- 5.2 times an hour. These posture shifts were merely a combination of posture shifts in the frontal and sagittal plane. Subcutaneous oxygen saturation increased on average 2.2% with each posture adjustment, indicating a positive effect of posture shifts on tissue viability. The results of this study can be used as a reference for seating interventions aimed at preventing pressure ulcers. Changing the sitting load at least every 8 minutes is recommended for wheelchair users

Myoelectric forearm prostheses: State of the art from a user-centered perspective

User acceptance of myoelectric forearm prostheses is currently low. Awkward control, lack of feedback, and difficult training are cited as primary reasons. Recently, researchers have focused on exploiting the new possibilities offered by advancements in prosthetic technology. Alternatively, researchers could focus on prosthesis acceptance by developing functional requirements based on activities users are likely to perform. In this article, we describe the process of determining such requirements and then the application of these requirements to evaluating the state of the art in myoelectric forearm prosthesis research. As part of a needs assessment, a workshop was organized involving clinicians (representing end users), academics, and engineers. The resulting needs included an increased number of functions, lower reaction and execution times, and intuitiveness of both control and feedback systems. Reviewing the state of the art of research in the main prosthetic subsystems (electromyographic [EMG] sensing, control, and feedback) showed that modern research prototypes only partly fulfill the requirements. We found that focus should be on validating EMG-sensing results with patients, improving simultaneous control of wrist movements and grasps, deriving optimal parameters for force and position feedback, and taking into account the psychophysical aspects of feedback, such as intensity perception and spatial acuity

Quality of Life After Sentinel Lymph Node Biopsy or Axillary Lymph Node Dissection in Stage I/II Breast Cancer Patients: A Prospective Longitudinal Study

Background:\ud Breast cancer patients’ quality of life (QoL) after surgery has been reported to improve significantly over time. Little is known about QoL recovery after sentinel lymph node biopsy (SLNB) in comparison to axillary lymph node dissection (ALND).\ud \ud Methods:\ud 175 of 195 stage I/II breast cancer patients completed the EORTC QLQ-C30: one day before surgery (T0) and after 6 (T1), 26 (T2), 52 (T3) and 104 (T4) weeks. Of these, 54 patients underwent SLNB, 56 SLNB+ALND and 65 ALND. General linear models and paired T-tests between T0–T4 and T1–T4 were computed. Complications, radiotherapy and systemic therapy were added to the model.\ud \ud Results:\ud Significant time effects were found on physical, role and emotional functioning. Physical and role functioning decreased between T0 and T1. At T4, SLNB patients’ functioning had increased to their T0 level; ALND (+/– SLNB) patients’ functioning had increased, but had not improved to T0 level. Emotional functioning increased linearly between T0 and T4. At T4, emotional functioning was significantly higher in all groups as compared with T0. No significant group or interaction (time × group) effects were found. Complications and chemotherapy had a significant negative effect on role, emotional and cognitive functioning. Complications had a significant effect on social functioning also. Effect sizes varied between 0.00 and 0.06.\ud \ud Conclusion:\ud Two years post surgery, breast cancer patients’ QoL is comparable to that shortly before surgery. Women rated their emotional functioning as even better. SLNB is not associated with a better QoL than ALND. However, undergoing systemic therapy and/or experiencing complications affects QoL negatively

Pushing the limits: A novel tape spring pushing mechanism to be used in a hand orthosis

A device that supports hand function may significantly improve the quality of life of patients with muscular weakness. Since tight constraints such as size and weight are placed upon the device, complexity of the hardware and functional performance should be carefully balanced. A novel force transmission mechanism based on tape springs is presented for use in a hand orthosis. The actuator force is transmitted to the finger by a system consisting of a tape spring, two slider blocks and an end stop per finger. The tape spring allows for bending in one direction, and resists bending in the other direction. A prototype with the new mechanism is constructed. The low profile together with the ability to transmit large forces makes this mechanism suitable for hand orthoses

Design of joint locks for underactuated fingers

Modern multifunctional hand prostheses have many degrees of freedom, but strong limitations on weight and size. The actuators commonly used in these systems are relatively large and heavy, so their number should be kept as low as possible. This is often accomplished by underactuation, which causes a natural motion of the fingers when grasping an object but reduces the ability to execute a variety of grasps. To remedy this, a series of locking mechanisms can be implemented to fix the position of one or more joints. This paper focuses on the development of such a joint locking system that could be used in anthropomorphic prosthetic fingers. Two lock concepts are implemented in a single-joint test setup and evaluated. A gear-based concept is tested, though its actuation requirements prove too high for viable implementation in a prosthesis. A mechanism based on friction amplification is shown to exhibit self-locking properties, which allows for a minimal lock actuation force while withstanding joint torques of over 2 Nm. The friction amplification mechanism is found suitable for prosthesis use, and will be developed further for implementation in a future prosthesis prototype

A front- and rear-view assistant for older cyclists:evaluations on technical performance, user experience and behaviour

The older cyclist is more prone to get cycling accidents than younger cyclists. To support the older cyclist, a rear- and front-view assistant were developed that warns the cyclist of approaching traffic. User tests to evaluate system performance, user-experience and effects on behaviour were performed with 20 older cyclists (>64 years) on a predefined route outdoors with and without support from both assistants. During this route, the cyclist was confronted with two controlled scenarios with an overtaking and an oncoming cyclist. The participants’ cycling behaviour was assessed by measuring lateral distance to the other cyclist, and distance maintained to the verge. The assistants had no effect on experienced mental workload. Both assistants received positive evaluations, although the rear-view assistant was experienced as more useful. Using the front-view assistant resulted in less lateral distance to the approaching oncoming cyclist, while the use of the rear-view assistant did not have effects on lateral distance

Dutch evidence-based guidelines for amputation and prosthetics of the lower extremity:Rehabilitation process and prosthetics. Part 2

Background: A structured, multidisciplinary approach in the rehabilitation process after amputation is needed that includes a greater focus on the involvement of both (para)medics and prosthetists. There is considerable variation in prosthetic prescription concerning the moment of initial prosthesis fitting and the use of replacement parts. Objectives: To produce an evidence-based guideline for the amputation and prosthetics of the lower extremities. This guideline provides recommendations in support of daily practice and is based on the results of scientific research and further discussions focussed on establishing good medical practice. Part 2 focuses on rehabilitation process and prosthetics. Study design: Systematic literature design. Methods: Literature search in five databases and quality assessment on the basis of evidence-based guideline development. Results: An evidence-based multidisciplinary guideline on amputation and prosthetics of the lower extremity. Conclusion: The best care (in general) for patients undergoing amputation of a lower extremity is presented and discussed. This part of the guideline provides recommendations for treatment and reintegration of patients undergoing amputation of a lower extremity and can be used to provide patient information. Clinical relevance This guideline provides recommendations in support of daily practice and is based on the results of scientific research and further discussions focussed on establishing good medical practice

Dutch evidence-based guidelines for amputation and prosthetics of the lower extremity:Amputation surgery and postoperative management. Part 1

BACKGROUND: Surgeons still use a range of criteria to determine whether amputation is indicated. In addition, there is considerable debate regarding immediate postoperative management, especially concerning the use of 'immediate/delayed fitting' versus conservative elastic bandaging.OBJECTIVES: To produce an evidence-based guideline for the amputation and prosthetics of the lower extremities. This guideline provides recommendations in support of daily practice and is based on the results of scientific research and further discussions focussed on establishing good medical practice. Part 1 focuses on amputation surgery and postoperative management.STUDY DESIGN: Systematic literature design.METHODS: Literature search in five databases. Quality assessment on the basis of evidence-based guideline development.RESULTS: An evidence-based multidisciplinary guideline on amputation and prosthetics of the lower extremity.CONCLUSION: The best care (in general) for patients undergoing amputation of a lower extremity is presented and discussed. This part of the guideline provides recommendations for diagnosis, referral, assessment, and undergoing amputation of a lower extremity and can be used to provide patient information.CLINICAL RELEVANCE: This guideline provides recommendations in support of daily practice and is based on the results of scientific research and further discussions focussed on establishing good medical practice.Geriatrics in primary car