Neuromimetic Event-Based Detection for Closed-Loop Tactile Feedback Control of Upper Limb Prostheses.

Upper limb amputees lack the valuable tactile sensing that helps provide context about the surrounding environment. Here we utilize tactile information to provide active touch feedback to a prosthetic hand. First, we developed fingertip tactile sensors for producing biomimetic spiking responses for monitoring contact, release, and slip of an object grasped by a prosthetic hand. We convert the sensor output into pulses, mimicking the rapid and slowly adapting spiking responses of receptor afferents found in the human body. Second, we designed and implemented two neuromimetic event-based algorithms, Compliant Grasping and Slip Prevention, on a prosthesis to create a local closed-loop tactile feedback control system (i.e. tactile information is sent to the prosthesis). Grasping experiments were designed to assess the benefit of this biologically inspired neuromimetic tactile feedback to a prosthesis. Results from able-bodied and amputee subjects show the average number of objects that broke or slipped during grasping decreased by over 50% and the average time to complete a grasping task decreased by at least 10% for most trials when comparing neuromimetic tactile feedback with no feedback on a prosthesis. Our neuromimetic method of closed-loop tactile sensing is a novel approach to improving the function of upper limb prostheses.

A picture of amputees and the prosthetic situation in Haiti.

PURPOSE: The purpose of this study is to present the situation of Haitian amputees and to outline some of the major barriers in Haiti that prevent people from receiving prosthetic treatment. METHOD: Interviews were conducted with amputees throughout Haiti using a 42-question questionnaire. Additionally, interviews were conducted with traditional healers, health care workers, and leaders of handicap associations. Each interview was manuscripted and the data were subsequently coded and analysed in the USA. RESULTS: There are three full-time prosthetic shops and two part-time prosthetic shops in Haiti, all of which are severely limited in the scope of services they are able to provide amputees due to insufficient supplies and inadequately trained personnel. Only 25% of the 164 amputees interviewed had ever had a prosthetic limb. Typically prosthetic treatment is inaccessible and unaffordable for amputees, which prevents many from seeking treatment. The most common cause of amputation in Haiti is infection, followed by motor vehicle accidents. CONCLUSION: There must be additional cooperation between Haitian patients, doctors, traditional healers, prosthetists, and government officials in order to provide more adequate prosthetic care. Prosthetic treatment in Haiti can be successful with cooperation of different entities, proper rehabilitation therapy, adequately trained personnel, and development of culturally appropriate limbs.

Acquired limb deficiencies. 3. Prosthetic components, prescriptions, and indications.

UNLABELLED: This self-directed learning module highlights indications for prosthetic components and prescription formulation for adults with acquired limb deficiency. It is part of the chapter on acquired limb deficiencies in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Advantages and disadvantages of specific components of upper and lower limb prostheses are discussed, and a sample prescription sheet for upper limb devices is included. Recent innovations in terminal devices for upper limb prostheses are reviewed. Special considerations for the adult with acquired multilimb deficiency are also examined. OVERALL ARTICLE OBJECTIVE: To describe indications for prosthetic components and prescription formulation for adults with acquired limb deficiency.

Sports and recreation for persons with limb deficiency.

UNLABELLED: Opportunities for persons with limb deficiency to participate in sport and recreational activities have increased dramatically over the past 20 years. Various factors have contributed to this phenomenon, including an increased public interest in sports and fitness as well as improvements in disability awareness. An even more essential element has been a consumer-driven demand for advances in prosthetic technology and design. Whether the activity is a music performance, a friendly round of golf, or a high-level track-and-field competition, the benefits of participation in sports and recreation are numerous both at the individual and at the societal level. This article provides an overview of the development and scope of sport and recreational opportunities available to persons with limb deficiency. In addition, specific prosthetic considerations for several common sport and recreational activities are presented in a case-discussion format. OVERALL ARTICLE OBJECTIVE: To review the development and scope of sport and recreational opportunities available to persons with limb deficiency.

Amputees in Limburg: incidence, morbidity and mortality, prosthetic supply, care utilisation and functional level after one year.

OBJECTIVES: To describe for the province of Limburg, the Netherlands, the incidence of lower limb amputation (LLA), the demographic characteristics of the amputees, reason and level of amputation, care the amputees receive, prosthetic supply and functional level after one year. DESIGN: A prospective descriptive cohort study. METHODS: Anonymized data on all amputees in all nine hospitals were collected during 1994. Follow-up was one year. RESULTS: 191 major lower limb amputations in 164 patients. Incidence was 17.1 per 100,000. Amputation levels: 77 trans-tibial, 52 transfemoral and 43 knee disarticulation. Twenty (20) patients died during hospitalisation. Eighty-seven (87) amputees gave permission for followup, 60 could be actually followed. Twenty-two (22) patients received in-patient rehabilitation, 16 primary day-care, 21 went to a nursing home and one went home without rehabilitation. The mean duration of rehabilitation was 35 weeks. In 53 patients a functional prosthesis was indicated. Forty-three (43) of these patients walked with the prosthesis after one year, 7 of whom more than 500 metres. Nineteen (19) amputees performed the Get Up and Go Test (GUGT) safely. Amputees on average have a low level of functioning, as indicated by SIP68 and Barthel Index Scores. The ability to walk is closely related to this daily function and quality of life. CONCLUSION: After one year the majority of amputees have low walking skills and the walking distance is limited. They are often ADL-dependent and their amputation greatly limits their daily function.

New concepts in lower limb orthotics.

Lower limb orthotics is in the process of a default transformation because of its association with lower limb prosthetics, a mechanical discipline that has translated component and material innovations into balance and velocity function gains to achieve a level of ambulation not possible a generation ago. This article discusses the fundamental mechanical similarities and differences of lower limb orthotics to prosthetics and their application to orthoses designed to improve the gait outcome of patients requiring orthotic intervention.

Developments in orthotic deweighting technology.

The ability to unload various aspects of the lower extremity has proven a useful orthotic treatment for a variety of pathologies. This article discusses and categorizes various orthotic techniques.

Transfemoral socket design and suspension options.

The transfemoral socket is the interface between the patient's residual limb and the remaining prosthesis. Whether the patient uses a technologically advanced knee mechanism and foot or a single axis, constant friction knee and solid ankle cushioned heel, no other prosthetic component is as crucial in assuring a comfortable and well-functioning prosthesis as the socket. This article discusses the rationale of quadrilateral and ischial containment socket designs and reviews suspension options.

Below knee prosthetic socket designs and suspension systems.

The prosthetic socket must act as a customized connection between the residual limb's surrounding tissues and the prosthetic components. The socket must be designed to control weight bearing, suspension, and ambulation stability. When making a below-the-knee socket, the prosthetist attempts to maximize loading and minimize displacements, such as vertical, transverse, or rotational. This article discusses the engineering designs or shapes of the two basic forms of below-the-knee prosthetic sockets used today.

Prosthetic knees.

The purpose of this article is to provide a framework for evaluating the features of a knee. A single knee unit has a combination of several control features. As is expected, new units are introduced with improvements to certain features. Prosthetic knee selection generally is based on the patient's ability. An inappropriate knee selection (or improper adjustment) may leave the patient apprehensive and fearful that the knee might buckle with each step. An appropriate selection of a properly adjusted knee unit closely matches the functional ability of the patient and yields a smooth, reliable gait.

The latest designs in prosthetic feet.

There are a great number of feet to choose from, some simple and nonadjustable, some more technically sophisticated and adjustable by prosthetist or patient. A foot must meet the lifestyle and prosthetic needs of the patient. One also must consider the maintenance requirements and how they are impacted by the amputees' living environment, distance from a prosthetic facility, and the patient's gadget tolerance. On the practical side, the manufacturer must stand behind their foot and offer a reasonable trial period. Today the physician, prosthetist, and physical therapist must be familiar with Medicare guidelines and K levels. Being informed enables the rehabilitation team to agree upon the componentry best suited for the amputee when generating the prescription. This approach also avoids unnecessary inquiries and helps assure payment. In closing, two statements are added: (1) a well-informed prosthetist with good communication skills and dedication to the details of socket fit and alignment is for the patient the best source of information concerning componentry; and (2) appropriateness, reliability, and convenience are good, general guidelines to follow when helping an amputee choose a prosthetic foot.

Upper extremity socket design options.

A careful evaluation of the amputee's physical situation is necessary to determine the best available prosthetic options. Evaluation of the psychologic and vocational needs are needed to determine the most appropriate designs. Other factors, such as hobby and sport activities, need to be determined to complete the prescription. Because the function of a prosthesis cannot restore all of the lost capability of the missing limb, every effort should be taken to provide the best available substitute by careful prescription, design, and construction.

Upper extremity myoelectric prosthetics.

Myoelectric control of upper limb prostheses has proven to be an effective and efficient means of controlling prosthetic components. This means of control has been used extensively for over 30 years, during which time these systems have become reliable and durable in most situations. Myoelectric control, or any other prosthetic control scheme, should not be considered as the optimal control for arm prostheses, but rather as one of the several effective ways of producing desired function. Advanced clinical practice calls for a blending of all control schemes, as appropriate, to allow the prosthesis to serve the intentions of the user efficiently and with little mental effort. Technology continues to change, bringing with it new and sometimes better ways of fitting amputees. Microprocessors and programmable controllers have opened new and exciting avenues for improvement in function. New, and as of yet unidentified, electronic and mechanical advances are certainly on the horizon. There is much work to be done before upper limb prostheses rightfully are called arm replacements. But progress is occurring and advances are being made toward the goal of replacing the function and appearance of that marvelous tool, the human arm.

Pediatric prosthetics. Current trends and future possibilities.

The child's growing, ever-changing nature presents a dynamic challenge to clinics that provide pediatric prostheses for children. Over the years clinics have developed strategies for prescribing and fitting pediatric prostheses. As new components, materials, or techniques are introduced, management of children with limb deficiencies may begin to take on a new look as well.

Custom design in lower limb prosthetics for athletic activity.

In summary, the prosthetist is the best source of information with regard to the fast-changing lower extremity prosthetics technology for sports. The needs and desires of the amputee should be outlined and balanced with the cost of the desired components and design. In many cases, one carefully designed prosthesis can serve in dual roles for everyday ambulation and certain athletic activities. In other cases, the amputee is limited severely by a prosthesis that is not designed for a specific activity. Using a prosthesis for activities that it was not designed to accommodate can cause physical injury to the amputee as well as structural failure of the device. A properly designed and fitted prosthesis can open a whole new world of activity to the amputee and helps him or her to reach the desired a vocational goals.

A five-year review of referrals for prosthetic treatment in England, Wales and Northern Ireland, 1981-85.

Patients undergoing amputation and who are considered to be suitable for an artificial leg are referred to the Disablement Services Centres (formerly called the Artificial Limb and Appliance Centres). This article reviews the referrals to the 23 centres in England, Wales and Northern Ireland over the five-year period 1981-85. The results show that there has been a decrease in the number of both upper and lower limb referrals and a 4% increase in the primary cause of amputation, arteriosclerosis. Centres that are the busiest, those seeing the greatest and fewest number of arteriosclerosis and diabetic referrals and those being referred the largest numbers of above, below and knee level amputations are identified.