This work describes a new human-in-the-loop (HitL) assistive grasping system for individuals with varying levels of physical capabilities. We investigated the feasibility of using four potential input devices with our assistive grasping system interface, using able-bodied individuals to define a set of quantitative metrics that could be used to assess an assistive grasping system. We then took these measurements and created a generalized benchmark for evaluating the effectiveness of any arbitrary input device into a HitL grasping system. The four input devices were a mouse, a speech recognition device, an assistive switch, and a novel sEMG device developed by our group that was connected either to the forearm or behind the ear of the subject. These preliminary results provide insight into how different interface devices perform for generalized assistive grasping tasks and also highlight the potential of sEMG based control for severely disabled individuals.
@cite_8: The Box and Block Test, a test of manual dexterity, has been used by occupational therapists and others to evaluate physically handicapped individuals. Because the test lacked normative data for adults, the results of the test have been interpreted subjectively. The purpose of this study was to develop normative data for adults. Test subjects were 628 Normal adults (310 males and 318 females) from the seven-county Milwaukee area. Data on males and females 20 to 94 years old were divided into 12 age groups. Means, standard deviations, standard error, and low and high scores are reported for each five-year age group. These data will enable clinicians to objectively compare a patient's score to a normal population parameter.
In order to evaluate the effectiveness of this system we used a pick and place task that was developed as a modification of the Box and Blocks Test of manual dexterity @cite_8 . This test is used to evaluate physically handicapped individuals to develop a normative metric for adults. We believe a test such as this is appropriate for evaluating whether the system developed is achieving a useful and or meaningful task. We opted for this instead of the Action Research Arm Test (ARAT) because it requires less than 1cm of noise for detecting the objects to be manipulated in that test and the equipment required for such precise point cloud measurements is not cost effective for an ordinary user at the time of this writing.