Abstract-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.

Robotic gait training is gaining ground in rehabilitation. Room for improvement lies in reducing donning and doffing time, making training more task specific and facilitating active balance control, and by allowing movement in more degrees of freedom. Our goal was to design and evaluate a robot that incorporates these improvements. LOPES II uses an end-effector approach with parallel actuation and a minimum amount of clamps. LOPES II has eight powered degrees of freedom (hip flexion/extension, hip abduction/adduction, knee flexion/extension, pelvis forward/aft and pelvis mediolateral). All other degrees of freedom can be left free and pelvis frontal- and transversal rotation can be constrained. Furthermore arm swing is unhindered. The end-effector approach eliminates the need for exact alignment, which results in a donning time of 10-14 min for first-time training and 5-8 min for recurring training. LOPES II is admittance controlled, which allows for the control over the complete spectrum from low to high impedance. When the powered degrees of freedom are set to minimal impedance, walking in the device resembles free walking, which is an important requisite to allow task-specific training. We demonstrated that LOPES II can provide sufficient support to let severely affected patients walk and that we can provide selective support to impaired aspects of gait of mildly affected patients.

No abstract

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.

Abstract-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.

Knowledge about long-term consequences of breast cancer treatment on shoulder and arm function and volume in stages I-II breast cancer survivors is limited. The effects of shoulder-arm function shortly after surgery on long-term function are unknown. One hundred and ninety-four women were examined pre-surgery (T0) and 6 weeks after surgery (T1). Of those, 110 were re-examined 7 years later (T2). Thirty-four women underwent sentinel lymph node biopsy (SLNB) and 76 underwent axillary lymph node dissection (ALND). Differences between affected and unaffected side were calculated for four ranges of motion functions, three strength functions and arm volume. These were used to analyse time and group effects. Differences exceeding 20° in range of motion, 20 % in strength and 200 ml in arm volume were considered clinically relevant. Multivariate regression analyses examined the effect of shoulder-arm function at T1 on shoulder-arm function at T2. Additional predictor variables included were age, follow-up time, Body Mass Index, complications, chemotherapy, radiation, SLNB/ALND and type of breast surgery. At T2, range of motion (except external rotation), abduction strength and arm volume were impaired compared to T0. After ALND, women had significantly more forward flexion impairment, increased arm volume and clinically relevant impairments (70 %) than after SLNB (41 %). T1 external rotation, abduction-external rotation, grip strength and arm volume were the strongest predictors of these variables at T2. Age was the strongest predictor of the remaining four variables. ALND predicted arm volume only. Seven years after breast cancer surgery, two-fifth of the women after SLNB and seven out of ten women after ALND had impairments. Impairments were found in five of eight shoulder-arm functions. After SLNB, women have less forward flexion impairment and less arm volume increase than after ALND. Shoulder-arm function at 6 weeks after surgery and age are the strongest predictors of long-term shoulder-arm function.

This study is a first step toward the implementation of sensory vibrotactile feedback for users of myoelectric forearm prostheses. Grasping force feedback is crucial for optimal object handling, and hand aperture feedback is essential for reduction of required visual attention. Grasping performance with feedback is evaluated for the potential users.

Background: 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).Methods: 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.Results: 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 9 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.Conclusion: 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.