Hongsun Guo
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Hongsun Guo has a total of 20 co-authors. Here are the top co-authors by number of shared publications:
- Hubert H. Lim
Department of Otolaryngology-Head and Neck Surgery, University of Minnesota, Minneapolis, USA
4 shared publications Cory D. Gloeckner
Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
2 shared publicationsJamu K. Alford
Restorative Therapies Group, Medtronic, Minneapolis, USA
2 shared publicationsSarah J. Offutt
Restorative Therapies Group, Medtronic, Minneapolis, USA
2 shared publicationsYohan Kim
Restorative Therapies Group, Medtronic, Minneapolis, USA
2 shared publications- Anh Tuan Nguyen
Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
1 shared publication
Latest Publications
- Open Access
- 9 February 2022
- Published by Springer Nature in Scientific Reports
- Vol. 12 (1) , 1-14
Ultrasound does not activate but can inhibit in vivo mammalian nerves across a wide range of parameters
Ultrasound (US) has been shown to stimulate brain circuits, however, the ability to excite peripheral nerves with US remains controversial. To the best of our knowledge, there is still no in vivo neural recording study that has applied US stimulation to a nerve isolated from surrounding tissue to confirm direct activation effects. Here, we show that US cannot excite an isolated mammalian sciatic nerve in an in vivo preparation, even at high pressures (relative to levels recommended in the FDA guidance for diagnostic ultrasound) and for a wide range of parameters, including different pulse patterns and center frequencies. US can, however, reliably inhibit nerve activity whereby greater suppression is correlated with increases in nerve temperature. By prohibiting the nerve temperature from increasing during US application, we did not observe suppressive effects. Overall, these findings demonstrate that US can reliably inhibit nerve activity through a thermal mechanism that has potential for various health disorders, though future studies are needed to evaluate the long-term safety of therapeutic ultrasound applications.
- 9 February 2022
- Published by Springer Nature in Scientific Reports
- Vol. 12 (1) , 1-14
Open AccessUltrasound does not activate but can inhibit in vivo mammalian nerves across a wide range of parameters
Ultrasound (US) has been shown to stimulate brain circuits, however, the ability to excite peripheral nerves with US remains controversial. To the best of our knowledge, there is still no in vivo neural recording study that has applied US stimulation to a nerve isolated from surrounding tissue to confirm direct activation effects. Here, we show that US cannot excite an isolated mammalian sciatic nerve in an in vivo preparation, even at high pressures (relative to levels recommended in the FDA guidance for diagnostic ultrasound) and for a wide range of parameters, including different pulse patterns and center frequencies. US can, however, reliably inhibit nerve activity whereby greater suppression is correlated with increases in nerve temperature. By prohibiting the nerve temperature from increasing during US application, we did not observe suppressive effects. Overall, these findings demonstrate that US can reliably inhibit nerve activity through a thermal mechanism that has potential for various health disorders, though future studies are needed to evaluate the long-term safety of therapeutic ultrasound applications.
- Open Access
- 23 October 2018
- Published by MDPI AG in Micromachines
- Vol. 9 (11) , 538
A Bidirectional Neuromodulation Technology for Nerve Recording and Stimulation
Electrical nerve recording and stimulation technologies are critically needed to monitor and modulate nerve activity to treat a variety of neurological diseases. However, current neuromodulation technologies presented in the literature or commercially available products cannot support simultaneous recording and stimulation on the same nerve. To solve this problem, a new bidirectional neuromodulation system-on-chip (SoC) is proposed in this paper, which includes a frequency-shaping neural recorder and a fully integrated neural stimulator with charge balancing capability. In addition, auxiliary circuits consisting of power management and data transmission circuits are designed to provide the necessary power supply for the SoC and the bidirectional data communication between the SoC and an external computer via a universal serial bus (USB) interface, respectively. To achieve sufficient low input noise for sensing nerve activity at a sub-10 V range, several noise reduction techniques are developed in the neural recorder. The designed SoC was fabricated in a 0.18 m high-voltage Bipolar CMOS DMOS (BCD) process technology that was described in a previous publication and it has been recently tested in animal experiments that demonstrate the proposed SoC is capable of achieving reliable and simultaneous electrical stimulation and recording on the same nerve.- 23 October 2018
- Published by MDPI AG in Micromachines
- Vol. 9 (11) , 538
Open AccessA Bidirectional Neuromodulation Technology for Nerve Recording and Stimulation
Electrical nerve recording and stimulation technologies are critically needed to monitor and modulate nerve activity to treat a variety of neurological diseases. However, current neuromodulation technologies presented in the literature or commercially available products cannot support simultaneous recording and stimulation on the same nerve. To solve this problem, a new bidirectional neuromodulation system-on-chip (SoC) is proposed in this paper, which includes a frequency-shaping neural recorder and a fully integrated neural stimulator with charge balancing capability. In addition, auxiliary circuits consisting of power management and data transmission circuits are designed to provide the necessary power supply for the SoC and the bidirectional data communication between the SoC and an external computer via a universal serial bus (USB) interface, respectively. To achieve sufficient low input noise for sensing nerve activity at a sub-10 V range, several noise reduction techniques are developed in the neural recorder. The designed SoC was fabricated in a 0.18 m high-voltage Bipolar CMOS DMOS (BCD) process technology that was described in a previous publication and it has been recently tested in animal experiments that demonstrate the proposed SoC is capable of achieving reliable and simultaneous electrical stimulation and recording on the same nerve. - Open Access
Ultrasound Produces Extensive Brain Activation via a Cochlear Pathway
Summary: Ultrasound (US) can noninvasively activate intact brain circuits, making it a promising neuromodulation technique. However, little is known about the underlying mechanism. Here, we apply transcranial US and perform brain mapping studies in guinea pigs using extracellular electrophysiology. We find that US elicits extensive activation across cortical and subcortical brain regions. However, transection of the auditory nerves or removal of cochlear fluids eliminates the US-induced activity, revealing an indirect auditory mechanism for US neural activation. US likely vibrates the cerebrospinal fluid in the brain, which is continuous with the fluid in the cochlea via cochlear aqueducts; thus, US can activate the ascending auditory pathways and other non-auditory regions through cross-modal projections. This finding of a cochlear fluid-induced vibration mechanism challenges the idea that US can directly activate neurons in the intact brain, suggesting that future US stimulation studies will need to control for this effect to reach reliable conclusions.
Open AccessUltrasound Produces Extensive Brain Activation via a Cochlear Pathway
Summary: Ultrasound (US) can noninvasively activate intact brain circuits, making it a promising neuromodulation technique. However, little is known about the underlying mechanism. Here, we apply transcranial US and perform brain mapping studies in guinea pigs using extracellular electrophysiology. We find that US elicits extensive activation across cortical and subcortical brain regions. However, transection of the auditory nerves or removal of cochlear fluids eliminates the US-induced activity, revealing an indirect auditory mechanism for US neural activation. US likely vibrates the cerebrospinal fluid in the brain, which is continuous with the fluid in the cochlea via cochlear aqueducts; thus, US can activate the ascending auditory pathways and other non-auditory regions through cross-modal projections. This finding of a cochlear fluid-induced vibration mechanism challenges the idea that US can directly activate neurons in the intact brain, suggesting that future US stimulation studies will need to control for this effect to reach reliable conclusions.