Advanced Electromyogram-Based Control of Hand-Wrist Prostheses

Many existing wearers of upper limb prostheses use the electrical activity (i.e., the electromyogram or “EMG”) of their residual limb to control hand opening/closing, wrist rotation, etc. However, one shortcoming of current control strategies is that they allow the user to control only one motion at a time, and do not allow for simultaneous, independent and proportional control of multiple joints. The desire to control multiple joints simultaneously is an oft cited desire of persons with upper limb amputation. LTI has partnered with Worcester Polytechnic Institute and Ms. Debra Latour, OTR/L, to develop and functionally evaluate a prosthesis controller that is capable simultaneous control of multiple joints with EMG-based control of a hand and wrist prostheses.

Research reported in this publication was supported by the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health under Award Number R42HD076519. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

The Intelligent Brace - A Compliance Monitoring System for Scoliosis

There is widespread use of bracing for treatment of Adolescent Idiopathic Scoliosis, and recent studies have begun documenting its efficacy and establishing a positive correlation between brace wear and treatment success. In light of this new evidence, ensuring the proper wear of a scoliosis brace is more crucial than ever. Currently the standard of treatment utilizes no means of monitoring fit once the patient leaves the clinic, and any devices that do exist only measure wear time and not whether the brace is being worn as tightly as prescribed. Both factors are crucial to achieving maximum benefit from the treatment. To address this, LTI has partnered with Pro-Tech Orthopedics, SurgiSense Corp, Texas Scottish Rite Hospital and the Minneapolis VA to develop an instrumented scoliosis brace which provides real-time monitoring and data logging to help both the patient and clinician determine if, and when, a brace is being worn effectively. The patient will get immediate feedback of poor fit, thus empowering him/her to have an active role in his or her own healthcare outcome. In addition, it would provide currently unavailable measures of wear compliance to the clinician to better inform brace treatment.

This work has been supported by the National Institute on Disability, Independent Living, and Rehabilitation Research.

Upper Limb Assistive and Rehabilitation Orthotic Device

One of the most common of military injuries are musculoskeletal injuries (MSI), which are inflicted upon thousands of individuals through combat and occupational risks. In addition, there are several medical conditions (e.g., stroke, brachial plexus injuries, ALS, etc.) that can lead to reduced hand function. The hands and arms of these individuals require treatment, assistance, and rehabilitation to restore function.

With funding from the Department of Defense’s (DoD’s) Defense Health Program (DHP), LTI and its partners from Worcester Polytechnic Institute (WPI), Debra Latour, OTR/L, Chris Lake, CPO, and Joseph Butkus, OTR/L, aim to create and functionally evaluate a low-profile, light-weight, and aesthetic device that can provide actuation to the fingers to create functional grip strength. A portable device that actuates the fingers externally could be used outside the clinic to increase strength and range of motion to assist the user in accomplishing their activities of daily living (ADLs).

This work is supported by the US Army Medical Research and Materiel Command under Contract No. W81XWH-15-C-0030. The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation.

Technologies to Train Myoelectric Prosthesis Users for Optimal Functional Outcomes

Successful outcomes of patients prescribed with myoelectric prostheses are dependent upon appropriate training to develop optimal use and function of the device. The critical time for developing good myoelectric control habits is in the pre-prosthetic phase (between wound healing and prosthesis delivery) but should continue after prosthesis delivery as well. Current myo-training devices rely on technologies that are expensive, manufacturer specific, and are typically non-motivating.

LTI, along with its partners from Coapt Engineering and Ms. Debra Latour, OTR/L, are creating a portable and affordable myoelectric training system that can be used both in the clinic and the home while creating a more engaging experience than current myoelectric trainers. The team will create a system that will likely improve compliance of patients wearing their prosthetic devices by allowing for more approachable and interactive myo-training. This device will likely increase the ease of myoelectric training and help lead to improved functional outcomes for the patient and cost savings for the health care provider.

This work is supported by the US Army Medical Research and Materiel Command under Contract No. W81XWH-15-C-0022. The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation.

Active Cooling Socket for Improving Residual Limb Comfort and Skin Care

The residual limb is typically covered by non-breathable and non-thermally conductive materials that can create a warm and ultimately moist environment. The trapped heat and perspiration can lead to potential skin irritation and infections, and decrease the usability of the prosthesis. A study of nearly 100 above-knee amputees found that heat and perspiration inside the socket were reported by 72% of the survey participants as the most common cause for a reduced quality of life. Other studies have found that even a small amount of activity can cause the socket temperature to elevate and remain at an uncomfortable level for an extended period, as the limb can’t cool efficiently within a standard prosthetic socket. To address this problem, LTI has partnered with Vivonics, Inc. and the Minneapolis VA to develop an active cooling system that can be integrated into the prosthetic socket and reduces residual limb temperatures to decrease perspiration and increase socket comfort.

This work is supported by the U.S. Army Medical Research and Material Command under contract no. W81XWH-17-C-0005.

Dynamic Corrective Force Device: A Balance Measure for Amputees

TLoss of balance is a significant problem for those who have undergone lower-limb amputations. Studies have shown that 52.4% of lower extremity amputees have reported falling in the previous year and 66% of above-knee amputees report falling annually, which is twice the rate of able-bodied adults over the age of 65. Given this, it is important to select the most appropriate components for each prosthetic device to maximize function while optimizing balance and stability to ultimately reduce the patient’s risk of falls. Therefore, we are developing a device to provide quantitative measures of balance to the clinician to aid in the selection of prosthetic feet and other components to optimize a patient’s stability and functional needs.

The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014 is the awarding and administering acquisition office. This work was supported by the Office of the Assistant Secretary of Defense for Health Affairs under award number W81XWH-15-1-0542 through the Orthotics and Prosthetics Outcomes Research.

Pointdexter: A Prosthetic Fingertip Terminal Device

Modern dynamic upper limb prosthetic terminal devices tend to either be functional or cosmetic, with most common designs making compromises between both aspects. Prosthetic hooks and grippers are particularly good at grasping a variety of objects but are not cosmetic. Conventional electric hands are more cosmetic, but do not allow for conforming grasp or multiple grasp patterns. Multi-articulating hands are also cosmetic, can conform to larger objects that are grasped, and offer multiple grasp patterns. However, both types of hands still have difficulty grasping and manipulating small objects.

As no single terminal device meets all of the criteria of an ideal terminal device, users often have to physically remove and don different terminal devices to achieve the variety of tasks that they need to perform in their activities of daily living (ADLs). LTI has been awarded funding from the National Institutes of Health (NIH) to develop a terminal device that can augment a prosthetic hand with an additional dexterous grip to provide the practicality and dexterity of a split-hook or gripper with the aesthetics of prosthetic hands.

Research reported in this publication was supported by the Eunice Kennedy Shriver National Institute Of Child Health & Human Development of the National Institutes of Health under Award Number R43HD090800. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Universal Open Power, Communications and Control for Assistive Devices

Numerous advanced prosthetic components have hit the market in recent years that have improved the functionality of prosthetic systems. Many of these devices are instrumented with various sensors and actuators. There are many scenarios where it would be beneficial to have devices be able to communicate with one another. For example, a powered ankle and knee sharing data could improve toe clearance during walking in an individual with transfemoral amputation. Unfortunately, a universally accepted method of inter-device communication does not yet exist in the prosthetics industry. Therefore, LTI has partnered with KCF technologies to develop an open platform that allows devices from different manufacturers to share data with one another to improve functional outcomes for prosthetic users.

This work is supported by the US Army Medical Research and Materiel Command under Contract No. W81XWH-15-C-0193.

Therapeutic Intermittent Compression Socket

Unlike persons with trauma-, cancer- and congenital- related amputation, patients with dysvascular amputations frequently experience a progression of the underlying disease that can result in additional, higher-level amputations. It can be estimated that over 2 billion is spent annually in the U.S. on costs related to reamputation of residual limbs that had undergone a prior, successfully healed major amputation. In addition to the substantial financial costs, data shows that more proximal amputations have a negative impact on numerous functional and psychosocial variables.

Rapid intermittent compression (IC) increases blood flow to the extremities, relieves rest pain, limits tissue damage, increases limb salvage rates, and has been used to treat a number of lower extremity vascular conditions. While IC has proven useful, patient compliance is an issue that hinders its success.

While several current commercial IC systems exist, none are truly portable due to the size and power consumption of the pneumatic pumps and reservoirs needed to create the pressure applied to the limb. Therefore, LTI, along with its partners at Brigham and Women’s Hospital and Willow Wood, are creating a portable system to conveniently provide IC therapy when the prosthesis is worn. Embedding the compression device into the socket would allow patients to have freedom of movement by not requiring them to be tethered to an electrical outlet and will likely dramatically increase patient compliance and therefore improve patient outcomes.

his work has been supported by the National Institute on Disability, Independent Living, and Rehabilitation Research.