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BALTIMORE, MD, United States

Kaplan P.W.,Johns Hopkins University | Schlattman D.K.,Infinite Biomedical Technologies, Llc
Journal of Clinical Neurophysiology | Year: 2012

Genetic epilepsies with generalized spike-wave complexes (GSWCs) and encephalopathy triphasic waves (TWs) may resemble each other and have three phases per complex. Electroencephalographic (EEG) interpretation is subjective, and EEGers have noted "TWs" in cases labeled nonconvulsive status epilepticus (NCSE). Direct comparison of both wave forms under the same conditions is rarely possible. In a single patient with generalized spike waves who developed hepatic TWs, morphologic characteristics of both were compared, and it was found that GSWCs have higher frequency first, second, and third phases; steeper phase 2 slope; and briefer after-going slow waves maximal at F3 to F4. Total complex duration was approximately 0.12 seconds. The TWs had dominant high-voltage phases 2 and 3 located more posteriorly, in the frontocentral region, lasting an average of approximately 0.32 seconds. These morphologic distinctions may help differentiate TWs from GSWCs. Copyright © 2012 by the American Clinical Neurophysiology Society. Source


Powell M.A.,Johns Hopkins University | Kaliki R.R.,Infinite Biomedical Technologies, Llc | Thakor N.V.,Johns Hopkins University
IEEE Transactions on Neural Systems and Rehabilitation Engineering | Year: 2014

We assessed the ability of four transradial amputees to control a virtual prosthesis capable of nine classes of movement both before and after a two-week training period. Subjects attended eight one-on-one training sessions that focused on improving the consistency and distinguishability of their hand and wrist movements using visual biofeedback from a virtual prosthesis. The virtual environment facilitated the precise quantification of three prosthesis control measures. During a final evaluation, the subject population saw an average increase in movement completion percentage from 70.8% to 99.0%, an average improvement in normalized movement completion time from 1.47 to 1.13, and an average increase in movement classifier accuracy from 77.5% to 94.4% (p<0.001). Additionally, all four subjects were reevaluated after eight elapsed hours without retraining the classifier, and all subjects demonstrated minimal decreases in performance. Our analysis of the underlying sources of improvement for each subject examined the sizes and separation of high-dimensional data clusters and revealed that each subject formed a unique and effective strategy for improving the consistency and/or distinguishability of his or her phantom limb movements. This is the first longitudinal study designed to examine the effects of user training in the implementation of pattern recognition-based myoelectric prostheses. © 2014 IEEE. Source


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 197.50K | Year: 2012

DESCRIPTION (provided by applicant): A new generation of dexterous prosthetic hands is becoming available, which are capable of a greater number of functions than conventional prostheses. To enable this increased functionality, we have pioneered a novel control platform which includes a surface electromyography (EMG) pattern recognition algorithm called MyoSense and a first-of-its-kind multi-channel conformal electrode interface called MyoLiner. The combination of these two technologies has allowed us, forthe first time, to give amputees the ability to point their index finger and operate their thumb independently in addition to the conventional hand open and close functionality. This technology has the potential to shift the paradigm in prosthetic controlfor the first time in over 50 years. In order to maximize the impact and accuracy of the technology, rehabilitation therapy is required, ideally within a 30-day golden window following amputation. However, the realities of patient fitting and medicaldevice reimbursement often delay the introduction of the prosthesis well beyond this period. Based on these considerations, we propose to integrate the innovative MyoLiner and MyoSense technologies with game-based training software into a complete patient-driven rehabilitation system named MyoTrain. Through our partnership with the top ranked video game design program at the University of Southern California, MyoTrain will be specifically designed to: 1) enable patients to practice using myoelectric control as early as possible during the golden window , 2) empower individuals to determine their own functional goals , 3) provide meaningful feedback to optimize a patient's ability to control their residual limb muscles, and 4) maximize the patient's engagement through exciting gameplay and meaningful rewards. At the conclusion of this development, we will validate the entire MyoTrain system, after 20 hours of use spread over 8 weeks, on clinically-validated upper limb functionality measures with transradial amputees. The study will be conducted by our partners at the Arm Amputee Program at the National Rehabilitation Hospital in Washington D.C. Upon completion of 20 hours of rehabilitation with the MyoTrain therapy, amputees will be expected to operate at least 6 functions independently with statistically significant improvements in real-time decoding accuracies and on the upper extremity functionality measures. With this improved functionality, we seek to usher in a new era of prosthetic control and improvethe effective functionality of dexterous prosthetic devices. PUBLIC HEALTH RELEVANCE: We propose developing novel rehabilitation system that will help amputees strengthen residual limb muscles and regain upper extremity functionality using dexterous myoelectric prostheses.


Grant
Agency: Department of Health and Human Services | Branch: National Institutes of Health | Program: SBIR | Phase: Phase I | Award Amount: 223.80K | Year: 2016

DESCRIPTION provided by applicant A new approach to suspension for upper limb myoelectric prostheses The overall goal of our research program is to empower upper limb amputees to be productive and independent For these individuals one of the most promising developments in the past decade has been the introduction of fully dexterous terminal devices However an effective and intuitive control strategy has remained elusive Myoelectric control typically utilizing two surface EMG electrodes works well for one or two degree of freedom devices but it is not as effective when dealing with a large number of movement classes such as when attempting to discriminate amongst andquot hand openandquot andquot index finger pointandquot andquot fine pinchandquot and so on Thus significant research has been undertaken on decoding the amputeeandapos s intention using signals from a larger number of surface EMG electrodes typically eight pairs However optimal performance is dependent on high quality surface EMG signal acquisition Small changes in electrode position or in contact between the electrode and the skin results in significant degradation in system performance One primary reason is that the design of the standard anatomically suspended prosthesis did not anticipate the evolution of prosthesis technology to include this need for highly stable multichannel surface EMG signal acquisition Thus there is a need to fundamentally rethink prosthesis design in light of the new opportunity to achieve dexterous control Specifically in this Fast Track effort we propose development of the MyoFit system to replace the standard anatomical suspended prosthesis It includes a roll on silicone gel liner which is fabricated to incorporate eight flexible surface EMG electrodes The liner and by extension the electrodes interfaces with the socket and frame of the prosthesis via a two part pin lock system The system enables a stable electrode skin interface including when the prosthesis is bearing load and when it is being moved to various positions in the workspace During Phase I we will develop and complete engineering validation of the liner and the lock In Phase II we will complete system integration and FDA regulatory clearance We will also undertake a clinical study to evaluate the functional benefits of the MyoFit system as compared to the standard anatomically suspended prosthesis It is our ultimate goal for the MyoFit system to enable upper limb amputees to achieve a superior clinical functional outcome PUBLIC HEALTH RELEVANCE The goal of our project is to improve the lives of upper extremity amputees Specifically we are developing several technologies which will allow electrical signals generated by the residual muscles in an amputees arm to be accurately read This will allow for an amputee to control the prosthetic device that they are using including prosthetic hands that can move in a variety of ways


Grant
Agency: Department of Health and Human Services | Branch: National Institutes of Health | Program: SBIR | Phase: Phase II | Award Amount: 719.36K | Year: 2015

DESCRIPTION provided by applicant Wireless Enhanced Myoelectric Control to Improve Upper Extremity Amputee Ability ABSTRACT The overall goal of our research program is to enable upper extremity amputees to be productive and independent For these individuals one of the most promising developments in the past decade has been the introduction of fully dexterous terminal devices However an effective and intuitive control strategy has remained elusive Myoelectric control works well for one or two degree of freedom devices but is not effective when dealing with a large number of movement classes such as when attempting to discriminate amongst andquot hand openandquot andquot index finger pointandquot andquot fine pinchandquot and so on Thus there is a need for a strategy to allow amputees to achieve a very high degree of freedom hand control to the level that they can accomplish complex tasks of daily living and working We now propose the development and validation of morph the Myoelectrically Operated RFID Prosthetic Hand morph is based on our pioneering and award winning concept of augmenting traditional electromyogram EMG control methodology with a radio frequency identification RFID tag based strategy The morph technology significantly enhances the capability of the hand to manipulate objects and tasks in an intuitive way by detecting object specific RFID tags morph empowers amputees by reliably giving them the right grip at the right time The RFID tags act as inputs for the prosthetic hand allowing automatic and immediate shifts in modes Specifically morph is designed to empower the user by providing greater control over the prosthesis increase reliability of the prosthesis increase the inventory of grips and modes of operation the user can readily access and carry out numerous daily dexterous functional tasks In this Fast Track effort we propose the creation and verification of morph the third party verification and validation of morph and an evaluation of morph in a long term clinical study of trans radial amputees It is our goal to deploy RFID augmented prostheses and to demonstrate the augmented EMG based control methodologies as the best individualized solution for each patient Our ambitious but compelling goal is to enable amputeesandapos independent living and enhance their productivity at work PUBLIC HEALTH RELEVANCE Dexterous prosthetic hands have the potential to greatly increase quality of life for upper limb amputees Unfortunately complicated and outdated control methods limit the potential that can the user can access In this project we will develop and launch morph a wireless controller that enables prostheses with greater function and more intuitive control It is our hope that this will increase the ability of amputees to live independet lives and to work productively

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