Creation of various skin sensations using pulsed focused ultrasound: Evidence for functional neuromodulation
Wonhye Lee, Hyungmin Kim, Sungon Lee, Seung‐Schik Yoo, Yong An Chung
International Journal of Imaging Systems and Technology 2014 · 10.1002/ima.22091
Abstract
Ultrasound application to neural tissues modifies their activity, and it is increasingly considered as a new mode of functional neuromodulation in both central and peripheral nervous system. We investigate that ultrasound focused to skin surface can induce differential peripheral sensations by modulating the activity of sensory receptors. Pulsed focused ultrasound was applied to the last digit of human hands for 10 s using combinations of acoustic frequencies (350 and 650 kHz), tone‐burst‐durations (0.1 and 1.0 ms), pulse repetition frequencies (10 and 100 Hz) with 1% duty cycle, and acoustic intensities (3–100 mW/cm 2 ), divided into two ambient temperatures (20 and 40°C). On insonification, volunteers reported cooling, warming, vibrotactile sensations, and mild nociception, while there was no actual increase to the skin temperature. Continuous insonification, in contrast to pulsed insonification, failed to elicit these sensations. Our results suggest that pulsed ultrasound temporarily modifies the activity of the sensory receptors on the skin, and casts future utility in dermatological applications as well as in the field of haptic device interfaces. © 2014 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 24, 167–174, 2014
Abstract via crossref.
Exposures
Exposure 1: 350 kHz pulsed FUS to fingertip, 20 and 40 C ambient
Target: other — “palm side on the tip of the fifth phalange”
Device: other named manufacturer · Channeltech, CA ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 350 | ✓✓✓ |
| Pulse duration (ms) | 0.1, 1swept | ✓✓✓⚑ |
| Pulse repetition frequency (Hz) | 100, 10swept | ✓✓✓ |
| Duty cycle (%) | 1 | ✓✓✓ |
| Sonication duration (s) | 10 | ✓✓✓ |
| Free-field pressure (kPa) | 118, 237, 284, 367, 639, 805, 958, 1,148swept | ✓✓✓⚑ |
|---|---|---|
| Free-field Isppa (W/cm²) | 0.3, 0.5, 0.7, 1, 3, 5, 7, 10swept | ✓✓✓ |
| Free-field Ispta (W/cm²) | 0.003, 0.005, 0.007, 0.01, 0.03, 0.05, 0.07, 0.1swept | ✓✓✓ |
| In-situ estimate | not applicable | |
| In-situ pressure (kPa) | not applicable | |
| In-situ Isppa (W/cm²) | not applicable | |
| In-situ Ispta (W/cm²) | not applicable |
Tone-burst duration 0.1 ms at PRF 100 Hz or 1.0 ms at PRF 10 Hz, both 1% duty cycle, 10 s insonification per parameter combination, repeated at ambient temperatures of 20 and 40 C. Continuous insonification at 100 mW/cm2 Ispta was also tested as a comparison.
Exposure 2: 650 kHz pulsed FUS to fingertip, 20 and 40 C ambient
Target: other — “palm side on the tip of the fifth phalange”
Device: other named manufacturer · Channeltech, CA ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 650 | ✓✓✓ |
| Pulse duration (ms) | 0.1, 1swept | ✓✓✓ |
| Pulse repetition frequency (Hz) | 100, 10swept | ✓✓✓ |
| Duty cycle (%) | 1 | ✓✓✓ |
| Sonication duration (s) | 10 | ✓✓✓ |
| Free-field pressure (kPa) | 210, 274, 339, 387, 645, 838, 935, 1,145swept | ✓✓✓ |
|---|---|---|
| Free-field Isppa (W/cm²) | 0.3, 0.5, 0.7, 1, 3, 5, 7, 10swept | ✓✓✓ |
| Free-field Ispta (W/cm²) | 0.003, 0.005, 0.007, 0.01, 0.03, 0.05, 0.07, 0.1swept | ✓✓✓ |
| In-situ estimate | not applicable | |
| In-situ pressure (kPa) | not applicable | |
| In-situ Isppa (W/cm²) | not applicable | |
| In-situ Ispta (W/cm²) | not applicable |
Tone-burst duration 0.1 ms at PRF 100 Hz or 1.0 ms at PRF 10 Hz, both 1% duty cycle, 10 s insonification per parameter combination, repeated at ambient temperatures of 20 and 40 C. Continuous insonification at 100 mW/cm2 Ispta was also tested as a comparison.
Flags from extraction
n_subjects— OCR renders n = 9 as 'n 5 9' in the textexposures[0].free_field.pressure_kpa— Pressures are per-intensity table values that differ by frequency; domain taken as free field because intensity was calibrated at the focus with a hydrophone in degassed water and no attenuation was applied; paper does not label the table column explicitlyexposures[0].timing.pulse_duration_ms— Pulse duration and PRF are paired (0.1 ms with 100 Hz, 1.0 ms with 10 Hz), recorded as parallel listssham_type— Continuous insonification at matched Ispta served as a comparison condition but is real output at a different waveform; recorded as no shamexposures[0].target.terms— Target is skin receptors of the fingertip; no matching target id, so other