Development of a Portable Synergy Resistant EMG-driven FES Device for Intuitive Control of Grasp and Release During Functional Arm Activities Following Stroke

Individuals with moderate to severe stroke will be recruited for both lab-based testing and home-based practice:

1. Pre-training clinical evaluation (lab-based). In this session, a research physical therapist will evaluate the participant's arm function and impairment level using standardized clinical assessments to ensure eligibility for participating in this study. Once confirmed, a set of standardized clinical assessments will be conducted by the research physical therapist as the baseline assessments of the participant's hand/arm function. This visit is expected to last approximately 3 hours.
2. Pre-training device setup (lab-based). The participant will be randomly assigned to one of the recruited physical therapists (PTs) or senior student physical therapists (SPTs) who has been recruited and consented to participate in this study. The assigned PT will determine 1) the electrode positions for recording the participant's muscle activities during the performance of different arm/hand functions, and 2) the stimulation electrode positions and stimulation intensities for achieving the best hand opening with the forearm at the individual's mid-range of available supination/pronation. Then, the corresponding electrode positions will be marked, and the forearm/hand with these markers will be scanned. This visit is expected to last approximately 3 hours. The scanned results will be used offline to develop a forearm-hand orthosis (FHO) that fits the participant's forearm and hand. During this visit, the investigators will measure the time for the PT/SPT to set up 1) recording electrodes, 2) detecting rules, 3) stimulation electrodes and configuration, and 4) the time for scanning.
3. Pre-training device-use learning sessions (2 visits, lab-based). After the FHO is ready, the participant will be called to participate in the 1st and 2nd lab-based training sessions for the use of ReIn-hand device. During these 2 visits, the assigned PT/SPT (1st test) or the research PT (2nd test) will train the participant to use the FHO and the ReIn-Hand software on a mobile device, until the participant demonstrates the ability in using the device independently twice in a row. During these 2 visits, the investigators will measure the time for the participant to 1) learn the use of the ReIn-Hand device (from the start of the session to the time that the participant is able to demonstrate ability to independently use the device twice in a row), 2) attach the FHO, 3) use the software for 1 trial (including connecting all the cables following the instructions, start the software and finish 1 trial), and 4) clean up. At the end of the 1st (for PTs) or the 2nd (for individuals with stroke) learning sessions, a 5min user survey will be conducted to report the level of ease-of-use of the ReIn-Hand device. During the 2nd learning session, the participant will also be re-tested on part of the clinical assessments, however, this time with the assistance of the ReIn-Hand device. Each of these 2 visits is expected to last about 3 hours.
4. Pre-training 2nd baseline clinical measures (lab-based). Within one week prior to starting the Home-based practice, a research PT will conduct the 2nd baseline clinical measures, which will repeat the 1st baseline clinical measures with an additional quantitative measure of maximal hand opening area and closing force (QMHOC). For QMHOC, pressure sensors (Pressure Profile Systems, Inc., Los Angeles, CA 90045) in conjunction with portable Moire Phase Tracking cameras (Metria Innovation, Inc., Wauwatosa, WI) will be used. The whole QMHOC will take about 10 minutes, and the whole 2nd baseline clinical measure session will take about 2 hours.
5. Pre-training EEG measures (lab-based). Within one week prior to starting the Home-based practice and within one week following completion of the 12-week Home-based practice, the participant will take part in an EEG experiment. During this session, a 9x9 mm marker will be placed on the tip of each finger, with another on the back of the hand as reference, which will allow for the measure of the position and angle of the fingers/hand by 2 portable Moire Phase Tracking cameras (180 Hz; Metria Innovation Inc. Milwaukee, WI). In addition, surface EEG electrodes will be mounted on a stretchable fabric cap based on the 10/20 system. A Polaris Krios handheld scanner and reflective markers (NDI, Ontario, Canada) will be used to record the EEG electrode positions compared to the coordinate system defined by the nasion, inion, and pre-auricular notches. Eye movement detection electrodes will also be placed on the supra- and infra-orbital margins for detection of vertical eye movement. EMG will be recorded from the extensor carpi radialis, flexor carpi radialis, and deltoid of the arm.

Once prepared, the participant will be seated in an experimental chair with: 1) adjustable straps across the shoulders and waist to maintain proper posture, 2) paretic forearm attached to an orthosis that is linked to the Arm Coordination Training 3D robot(ACT-3D), a robot that will provide required arm support, 3) hand around a cylinder with a custom pressure sensor mat (Pressure Profile System Inc., CA). The participant will be instructed to perform 1 of 2 movements: 1) hand opening while resting on a haptic table, or 2) hand opening while lifting against 50% of their maximum shoulder abduction force. The investigator will measure scalp recordings and EMG recordings using a 160-channel EEG/EMG system using active electrodes (Biosemi, Inc., Active II, Amsterdam, The Netherlands), hand opening area or finger flexion force. 6. Home-based practice. After above 5 lab-based visits, participants will take the ReIn-Hand device, including the FHO, the mobile device with ReIn-Hand software, and the electronic stimulator (EMPI 300PV, Minnesota, USA, a FDA approved clinical device) back home. At home, participants will perform 20 trials of pre-set tasks, like reaching and grasping, per session (1 hour), 1 session per day, 7 days per week for 12 weeks. During these 12 weeks, the participant will visit the lab once per week to make necessary device changes, and perform part of the clinical assessments and QMHOC measure without the ReIn-hand. 7. Post-training tests (lab-based). The sessions #4 mentioned above will be repeated at one week and 3-month after the 12-week home-based practice. The session #5 will be repeated at one week after the 12-week home-based practice. All the post-training tests will be preformed without ReIn-hand device.