Effects of cognitive load and prosthetic liner on volitional response times to vibrotactile feedback

Abstract

Abstract-Artificial tactile feedback systems can improve prosthetic function for people with amputation by substituting for lost proprioception in the missing limb. However, limited data exists to guide the design and application of these systems for mobility and balance scenarios. The purpose of this study was to evaluate the performance of a noninvasive artificial sensory feedback (ASF) system on lower-limb function in the presence of a cognitive load and a liner interface. Reaction times (RTs) and accuracy of leg-movement responses to vibratory stimuli at the thigh were recorded for 12 nondisabled individuals and 3 participants with transfemoral amputation using a custom-built testing apparatus. The results indicate that the addition of a cognitive load increases response times relative to the baseline condition by 0.26 to 0.33 s. The prosthetic liner produced a less pronounced increase in RT of 0.06 to 0.11 s. Participants were able to correctly identify the stimulus location with nearly 100% accuracy. These increased RTs are nontrivial and must be considered in designing ASF systems.

A New Sensory Feedback System for Lower-Limb Amputees: Assessment of Discrete Vibrotactile Stimuli Perception During Walking

“…The percentage of correct perceptions was 40% with the lowest stimulation level and higher than 97% with 70% and 100% stimulation levels. A similar trend was observed in a previous study [8], where the RTs were computed to compare three vibration frequencies: 140, 180, and 220 Hz, with the latter resulting in the shortest RT.…”

“…The stimulation duration of 100 ms was selected to achieve clear perception without overlap between successive vibrations, annoyance or adaptation effects [3], [4], [7], [8]. The number of steps occurring between two consecutive activations was randomized to avoid possible bias due to expectation.…”

Biofeedback Systems for Gait Rehabilitation of Individuals with Lower-Limb Amputation: A Systematic Review

“…BFB approaches in rehabilitation have been studied in a variety of patient populations including stroke [37,[40][41][42], Parkinson's disease [43][44][45], cerebral palsy [46], vestibular deficits [47,48], diabetes [49], and upper-limb [50,51] and lower-limb amputees [31,52,53]. As well as in a variety of applications, including static and dynamic postural balance [54][55][56], walking [57][58][59], stairs management [60], obstacle avoidance [61], floor conditions identification [62], and sensory perception [31,53,63], to mention a few. In 2018, a mapping review [64] was published regarding the use of BFB for gait retraining.…”

Perception of Time-Discrete Haptic Feedback on the Waist is Invariant With Gait Events

“…In this scenario, identifying VT intensity and frequency perception thresholds at different body sites is paramount to deliver effective stimulation. With the goal to develop VT-based lower-limb sensory feedback devices, few studies investigated VT perception on different body areas, most of which were carried out in static, very-structured, experimental conditions [13]- [16]. However, one of the most critical factors influencing tactile perception during dynamic voluntary movements such as walking is the underlying muscle activation.…”

“…Furthermore, through the torso, spatial information can be conveyed in an intuitive way since the stimuli are directly mapped to the body coordinates. In the field of gait rehabilitation, few research groups applied VT stimuli to the torso for improving postural control [29]- [32] or providing foot-ground contact information [33], [34], while the main targeted site for haptic feedback remained the thigh [10], [13], [15], [35]- [39]. On the other hand, most of the studies on haptic displays for visually impaired persons focused on the delivery of VT stimuli on the abdomen to indicate a direction of travel [2], [4]- [6], [28].…”