Hand Extension Robot Orthosis (HERO) Glove: Development and Testing With Stroke Survivors With Severe Hand Impairment

Abstract

The hand extension robot orthosis (HERO) glove was iteratively designed with occupational therapists and stroke survivors to enable stroke survivors with severe hand impairment to grasp and stabilize everyday objects, while being portable, lightweight, and easy to set up and use. The robot consists of a batting glove with artificial tendons embedded into the glove's fingers. The tendons are pulled and pushed by a linear actuator to extend and flex the fingers. The robot's finger extension and grasp assistance are automated using inertial measurement unit signal thresholds. Five stroke survivors (Chedoke McMaster Stroke Assessment -Stage of Hand 1-3) put on the HERO Glove in 1-3 minutes, with assistance. The stroke survivors performed significantly better on the Box and Block Test (2.8 more blocks transferred, p < 0.01) while wearing the HERO Glove than when not wearing the glove. Four stroke survivors could only transfer blocks while wearing the HERO Glove. The HERO Glove enabled these stroke survivors to more fully extend their index finger (an increase of 97.5 • , p < 0.01) and three of five stroke survivors were better able grasp a water bottle. Therapists and stroke survivors suggested increasing the HERO Glove's grip force assistance and valued the glove's portability, lightweight design and potential usefulness in assisting with task-based therapy.

Hand Extension Robot Orthosis (HERO) Grip Glove: enabling independence amongst persons with severe hand impairments after stroke

“…For studies by Cappello et al and Soekadar et al with six and nine persons with impaired hands following a spinal cord injury, wearable hand robots have increased grip strength to 4 N [12] and ADL performance to 5.5 out of 7 on the Toronto Rehabilitation Institute -Hand Function Test by assisting pinch and palmar grasp postures [12,13]. For a study by Yurkewich et al with five persons with severely impaired hands following stroke (no voluntary index finger extension), a previous version of the HERO Grip Glove named the HERO Glove increased ROM to 79 o and improved water bottle and block grasping performance [14]. Refer to [14] for a supplementary table detailing recently developed wearable hand robots, their capabilities and their evaluation results.…”

“…For a study by Yurkewich et al with five persons with severely impaired hands following stroke (no voluntary index finger extension), a previous version of the HERO Grip Glove named the HERO Glove increased ROM to 79 o and improved water bottle and block grasping performance [14]. Refer to [14] for a supplementary table detailing recently developed wearable hand robots, their capabilities and their evaluation results. Hand robots need to be improved to generate strong extension and grip forces that overcome muscle tone and securely stabilize various object geometries, such as a water bottle and a fork.…”

“…Hand robots need to be improved to generate strong extension and grip forces that overcome muscle tone and securely stabilize various object geometries, such as a water bottle and a fork. These robots should also be easy to put on clenched hands, comfortable during multiple hours of use, lightweight so as not to affect the motion of weak arms and affordable so they are accessible to people with limited income even though these considerations create design tradeoffs that sacrifice assistive capabilities [14,15].…”

“…A number of sensor types (i.e. button [12,14,16], electromyography [17,18], motion [10,14], force [19], voice [20], vision [21,22] and electroencephalography [13] have been selected to control robot assistance based on varied motivations such as robust operation or motivating neuromuscular activation. However, other than button control, these control strategies are still in an experimental stage that requires experts to manually tune each user's orthosis [17].…”

“…The HERO Grip Glove was iteratively designed with stroke survivors and therapists to meet their design specifications, shown in Table 1. These design specifications are shown in Table 1 of [14], and are based on qualitative and quantitative feedback gathered from Fig. 1 The HERO Grip Glove assists finger and thumb extension and flexion to enable users to grasp large and small objects.…”