Functional MRI in Conjunction with a Novel MRI-compatible Hand-induced Robotic Device to Evaluate Rehabilitation of Individuals Recovering from Hand Grip Deficits

Summary

We performed functional MRI using a novel MRI-compatible hand-induced robotic device to evaluate its utility for monitoring hand motor function in individuals recovering from neurological deficits.

Abstract

Functional magnetic resonance imaging (fMRI) is a non-invasive magnetic resonance imaging technique that images brain activation in vivo, using endogenous deoxyhemoglobin as an endogenous contrast agent to detect changes in blood-level-dependent oxygenation (BOLD effect). We combined fMRI with a novel robotic device (MR-compatible hand-induced robotic device [MR_CHIROD]) so that a person in the scanner can execute a controlled motor task, hand-squeezing, which is a very important hand movement to study in neurological motor disease. We employed parallel imaging (generalized auto-calibrating partially parallel acquisitions [GRAPPA]), which allowed higher spatial resolution resulting in increased sensitivity to BOLD. The combination of fMRI with the hand-induced robotic device allowed precise control and monitoring of the task that was executed while a participant was in the scanner; this may prove to be of utility in rehabilitation of hand motor function in patients recovering from neurological deficits (e.g., stroke). Here we outline the protocol for using the current prototype of the MR_CHIROD during an fMRI scan.

Introduction

Appropriate imaging metrics may monitor and predict the likelihood of therapy success in individuals better than clinical assessments and provide information to improve and individualize therapy planning. We have developed experience with patients recovering from chronic stroke^{1,2,3,4,5,6,7,8}. Developing optimal individualized strategies that focus on how motor training can influence incremental improvem....

Protocol

All experiments were approved by the Institutional Review Board at Massachusetts General Hospital and performed as approved at the Athinoula A. Martinos Center for Biomedical Imaging.

1. Subject Preparation

NOTE: Inclusion criteria are: (i) right hand dominance, (ii) ability to give written informed consent. Exclusion was implemented on the basis of screening for contra-indicators in the magnetic resonance environment such as the following: (a) Routine MRI exclusion criteria, such as the presence of a pacemaker or cerebral aneurysm clip and metal implants or metal content in body; (b) history of se....

Results

The methodology outlined in the protocol allows the collection of fMRI images while the volunteer is performing the task in real-time in the magnet. Experiments were performed in the Bay 1 facility of the Massachusetts General Hospital Athinoula A. Martinos Center for Biomedical Imaging, using a 3T full-body magnetic resonance scanner. Figure 2 and Figure 3 show the placement of the MR_CHIROD on the table and the patient in place operating it. In

Discussion

We present fMRI of a motor task using the latest version of a novel robotic device, the MR_CHIROD^1,2,8. The MR_CHIROD has been designed to execute a hand-squeezing grip task which has can be performed by chronic stroke patients and has been studied previously^1,2,3,4,5.......

Materials

Name	Company	Catalog Number	Comments
Ball bearings, plastic with glass balls (8)	McMaster-Carr	6455K97
Bi-directional logic level converter	Adafruit	395
Dual LS7366R Quadrature Encoder Buffer	SuperDroid Robots	TE-183-002
Feather M0 WiFi w/ATWINC1500	Adafruit	Adafruit 3010
Flanged nuts, fiberglass, 3/8”-16 (8)	McMaster-Carr	98945A041
Garolite rod, ¾” dia, 4’ long	McMaster-Carr	8467K84
Laptop	Various		Any laptop with USB2.0 port(s) and MATLAB
Load Cell (20kg)	Robotshop	RB-PHI-119
Load Cell Amplifier- HX711	Mouser	474-SEN-13879
MATLAB	MathWorks		2008 version or later with Psychophysics Toolbox
Magnetic resonance imaging scanner	Siemens	Skyra 3T	3T full body scanner with BOLD and GRAPPA capabilities
MR_CHIRODv3	fabricated in-house		Bespoke plastic & 3D printed structure
Op amp development board	Schmartboard	710-0011-01
Panel Mount Power Supply	Delta	PMT-D2V100W1AA
Plastic tubing & tube fittings	McMaster-Carr	various
Pyrex/graphite piston/cylinder module	Airpot	2KS240-3
Screws, ¼”-20, nylon	McMaster-Carr	various
Shaft Collars for ¾” dia shaft, nylon (2)	McMaster-Carr	9410T6	Stock metal clamping screws replaced with plastic screws
Shielded cables (2)	US Digital	CA-C5-SH-C5-25
Threaded rod, fiberglass, 3/8”-16	McMaster-Carr	91315A010
Transmissive optical encoder code strip	US Digital	LIN-2000-3.5-0.5
Transmissive Optical Encoder Module	US Digital	EM2-0-2000-I
PTFE sleeve bearings	McMaster-Carr	2639T32