TY - GEN
T1 - Acoustoelectric detection of current flow in a neural recording chamber
AU - Witte, R. S.
AU - Olafsson, R.
AU - O'Donnell, M.
PY - 2006
Y1 - 2006
N2 - Acoustic pressure (P) traveling in a biologic fluid or tissue generates a local change in electrical conductivity. This acoustoelectric interaction (AE) induces a voltage modulation that depends on local current, resistance, and pressure. We explore the AE signal as a way to enhance traditional electrophysiology or surface recording of neural signals. A thin stretch tube mimicking an enlarged axon and an abdominal segment of a fresh lobster nerve cord were used as test structures for AE detection in a tri-compartment neural recording chamber. Stimulating electrodes passed low frequency current through the structures, while a pair of recording electrodes detected the high frequency AE signal. Ultrasound transducers from 0.5 to 7.5 MHz delivered P up to 2 MPa. The differentially-recorded AE signal was captured on a fast data acquisition board and saved for post processing. In the lobster nerve cord, the AE signal was linear between the tested range of current densities of 9 to 86 mA/cm 2 [18 dB/log(J), r2=0.96] and P of 0.5 to 2 MPa [21 dB/log(P), r2=0.96]. In addition, a transverse scan of the structures produced cross-sectional AE images of current flow with remote detection by the recording electrodes. Results were consistent with AE simulations. This study demonstrates that the AE signal can be used to detect and image current flow in a biologic environment with physiologically-relevant current densities and acoustic pressures on par with clinical ultrasound imaging.
AB - Acoustic pressure (P) traveling in a biologic fluid or tissue generates a local change in electrical conductivity. This acoustoelectric interaction (AE) induces a voltage modulation that depends on local current, resistance, and pressure. We explore the AE signal as a way to enhance traditional electrophysiology or surface recording of neural signals. A thin stretch tube mimicking an enlarged axon and an abdominal segment of a fresh lobster nerve cord were used as test structures for AE detection in a tri-compartment neural recording chamber. Stimulating electrodes passed low frequency current through the structures, while a pair of recording electrodes detected the high frequency AE signal. Ultrasound transducers from 0.5 to 7.5 MHz delivered P up to 2 MPa. The differentially-recorded AE signal was captured on a fast data acquisition board and saved for post processing. In the lobster nerve cord, the AE signal was linear between the tested range of current densities of 9 to 86 mA/cm 2 [18 dB/log(J), r2=0.96] and P of 0.5 to 2 MPa [21 dB/log(P), r2=0.96]. In addition, a transverse scan of the structures produced cross-sectional AE images of current flow with remote detection by the recording electrodes. Results were consistent with AE simulations. This study demonstrates that the AE signal can be used to detect and image current flow in a biologic environment with physiologically-relevant current densities and acoustic pressures on par with clinical ultrasound imaging.
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U2 - 10.1109/ULTSYM.2006.16
DO - 10.1109/ULTSYM.2006.16
M3 - Conference contribution
AN - SCOPUS:47249138762
SN - 1424402018
SN - 9781424402014
T3 - Proceedings - IEEE Ultrasonics Symposium
SP - 5
EP - 8
BT - 2006 IEEE International Ultrasonics Symposium, IUS
T2 - 2006 IEEE International Ultrasonics Symposium, IUS
Y2 - 3 October 2006 through 6 October 2006
ER -