Utility of contact detection reflexes in prosthetic hand control

Evaluation of force, vibration and thermal tactile feedback in prosthetic limbs

“…In these experiments, contact forces were measured using the pressure sensor, which has been demonstrated to provide contact sensitivity that exceeds even human performance [17]. (Figure 1, top-right) using methods described in [1]. "Dummy" BioTacs (containing no electronics) were mounted on the middle finger and thumb to produce stable gripping points.…”

“…"Dummy" BioTacs (containing no electronics) were mounted on the middle finger and thumb to produce stable gripping points. The prosthetic hand was controlled using EMG signals being recorded from the subject's socket and the controllers developed in [1]. Signals from the BioTac were collected in LabVIEW and processed to drive the tactors as discussed below.…”

“…Weights were presented in random order for the following pairs (values in grams): 200/100, 100/50, 120/100, 70/50, 110/100, and 105/100. A variant of this test was conducted to better evaluate the subject's confidence in 1 Air muscle pressure was related to, but not proportional to squeezing pressure, which was estimated to be approximately 30-40 times less. his answers by creating a third option of holding up three fingers to indicate that the weights felt the same.…”

“…Two approaches have been suggested to make use of tactile information in prosthetic devices: tactile feedback can be used to enable autonomous reflexes making prosthetic hand control more natural and intuitive [1], and tactile information can be provided directly to the user for conscious perception. To provide tactile information to prosthesis users, many groups have developed tactile displays to stimulate the residual skin and nerves of an amputee.…”

“…Tactile sensing in the human hand can be used for both autonomous reflexes and conscious perception. In a previous study we had explored using tactile sensing for autonomous reflexes to enable fragile object grasping [1], in this study we evaluate the benefits and performance in conscious perception of force, vibration and thermal tactile information. A prosthetic hand equipped with a BioTac sensor (capable of sensing force, vibration and temperature) and different tactors developed to play back these feedback modalities on a subject's forearm were used to evaluate perception in tactile discrimination experiments.…”