TY - JOUR
T1 - Electrotactile and Vibrotactile Feedback Enable Similar Performance in Psychometric Tests and Closed-loop Control
AU - Dideriksen, Jakob
AU - Markovic, Marko
AU - Lemling, Sabrina
AU - Farina, Dario
AU - Dosen, Strahinja
PY - 2022/1
Y1 - 2022/1
N2 - Electro-and vibro-tactile stimulation are commonly employed for feedback in closed-loop human-machine interfacing. Although these feedback systems have been extensively investigated individually, they are rarely objectively compared. In this study, two state-of-the-art stimulation units (concentric electrode and C2-tactor) similar in shape and size were compared in psychometric and online control tests. The just noticeable difference and number of discriminable levels for intensity and frequency modulation were determined across values of carrier frequency and intensity, respectively. Next, subjects performed a compensatory tracking task, in which the feedback encoded the momentary tracking error. In the psychometric tests, intensity modulation outperformed frequency modulation and electrotactile stimulation enabled significantly higher resolution than vibrotactile stimulation, for the same carrier frequency. However, for the best-case settings (eletro-tactile: 100 Hz; vibro-tactile: 200 Hz), the two stimulation modalities were equivalent in the psychometric tests and in the online control tests, where the two stimulation methods resulted in similar correlation and deviation between the target and the generated trajectory. Time delay was slightly but significantly lower for the vibrotactile modality. Overall, the present assessment shows that despite psychometric differences between the two stimulation methods, they enable similar online control performance when parameters are optimally selected for each modality.
AB - Electro-and vibro-tactile stimulation are commonly employed for feedback in closed-loop human-machine interfacing. Although these feedback systems have been extensively investigated individually, they are rarely objectively compared. In this study, two state-of-the-art stimulation units (concentric electrode and C2-tactor) similar in shape and size were compared in psychometric and online control tests. The just noticeable difference and number of discriminable levels for intensity and frequency modulation were determined across values of carrier frequency and intensity, respectively. Next, subjects performed a compensatory tracking task, in which the feedback encoded the momentary tracking error. In the psychometric tests, intensity modulation outperformed frequency modulation and electrotactile stimulation enabled significantly higher resolution than vibrotactile stimulation, for the same carrier frequency. However, for the best-case settings (eletro-tactile: 100 Hz; vibro-tactile: 200 Hz), the two stimulation modalities were equivalent in the psychometric tests and in the online control tests, where the two stimulation methods resulted in similar correlation and deviation between the target and the generated trajectory. Time delay was slightly but significantly lower for the vibrotactile modality. Overall, the present assessment shows that despite psychometric differences between the two stimulation methods, they enable similar online control performance when parameters are optimally selected for each modality.
KW - Electrodes
KW - Electrotactile stimulation
KW - Frequency modulation
KW - Pain
KW - Shape
KW - Skin
KW - Task analysis
KW - Vibrations
KW - closed-loop control
KW - psychometrics
KW - sensory feedback
KW - sensory substitution
KW - vibrotactile stimulation
KW - Closed-loop control
KW - electrotactile stimulation
UR - http://www.scopus.com/inward/record.url?scp=85117122319&partnerID=8YFLogxK
U2 - 10.1109/TOH.2021.3117628
DO - 10.1109/TOH.2021.3117628
M3 - Journal article
SN - 1939-1412
VL - 15
SP - 222
EP - 231
JO - IEEE Transactions on Haptics
JF - IEEE Transactions on Haptics
IS - 1
M1 - 9562749
ER -