TY - GEN
T1 - Skull Impact on the Ultrasound Beam Profile of Transcranial Focused Ultrasound Stimulation
AU - Tsai, Pin Chien
AU - Gougheri, Hesam Sadeghi
AU - Kiani, Mehdi
N1 - Funding Information:
This work was supported by the National Institutes of Health under Grant 1R21EY029424
Publisher Copyright:
© 2019 IEEE.
PY - 2019/7
Y1 - 2019/7
N2 - Transcranial focused ultrasound stimulation (tFUS) is a promising noninvasive neuromodulation tool for targeting brain regions with millimeter-scale spatial resolutions. In conventional tFUS studies, a focused ultrasound beam generated by an external ultrasound transducer is delivered to the neural target. In tFUS, ultrasound should travel through the skull that features large attenuation and different acoustic impedance compared with the soft tissue, thereby resulting in acoustic impedance mismatch and reflections. In this paper, we study the impact of the rat skull on the ultrasound beam profile generated by both focused and unfocused (but with a natural focus) transducers at a wide sonication frequency (fp) range of 0.5-9.5 MHz. At different axial and lateral distances from the transducers, we measured ultrasound intensity profiles of three transducers operating at fps of 0.5 MHz, 1.2 MHz and 9.5 MHz with and without the skull. Our results showed that ultrasound beam profiles were significantly distorted by the skull. The transmission factor due to skull attenuation was measured 0.79,0.34 and 0.03 at fps of 0.5 MHz, 1.2 MHz and 9.5 MHz, respectively, when the skull was close to transducers focal zones.
AB - Transcranial focused ultrasound stimulation (tFUS) is a promising noninvasive neuromodulation tool for targeting brain regions with millimeter-scale spatial resolutions. In conventional tFUS studies, a focused ultrasound beam generated by an external ultrasound transducer is delivered to the neural target. In tFUS, ultrasound should travel through the skull that features large attenuation and different acoustic impedance compared with the soft tissue, thereby resulting in acoustic impedance mismatch and reflections. In this paper, we study the impact of the rat skull on the ultrasound beam profile generated by both focused and unfocused (but with a natural focus) transducers at a wide sonication frequency (fp) range of 0.5-9.5 MHz. At different axial and lateral distances from the transducers, we measured ultrasound intensity profiles of three transducers operating at fps of 0.5 MHz, 1.2 MHz and 9.5 MHz with and without the skull. Our results showed that ultrasound beam profiles were significantly distorted by the skull. The transmission factor due to skull attenuation was measured 0.79,0.34 and 0.03 at fps of 0.5 MHz, 1.2 MHz and 9.5 MHz, respectively, when the skull was close to transducers focal zones.
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U2 - 10.1109/EMBC.2019.8857269
DO - 10.1109/EMBC.2019.8857269
M3 - Conference contribution
C2 - 31947027
AN - SCOPUS:85074972180
T3 - Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS
SP - 5188
EP - 5191
BT - 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019
Y2 - 23 July 2019 through 27 July 2019
ER -