Patterned Interference Radiation Force for Transcranial Neuromodulation

Kim, Young Hun; Kang, Ki-Weon; Kim, Jeong Nyeon; Pai, Chi Nan; Zhang, Yichi; Ghanouni, Pejman; Park, Kwan Kyu; Firouzi, Kamyar; Khuri-Yakub, B.T.

doi:10.1016/j.ultrasmedbio.2021.11.006

Cited by 4 publications

(3 citation statements)

References 48 publications

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“…Acoustic radiation force is also considered one of the physical mechanisms underlying effective neuromodulation. The two opposing transducers used in this study create a standing wave at the focus that generates a significantly larger acoustic radiation forces than single element transducers [50], which may enhance the effectiveness of the neuromodulation [4,51].…”

Section: Discussionmentioning

confidence: 99%

Noninvasive modulation of essential tremor with focused ultrasonic waves

Riis,

Losser,

Kassavetis

et al. 2024

J. Neural Eng.

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Transcranial focused low-intensity ultrasound has the potential to noninvasively modulate confined regions deep inside the human brain, which could provide a new tool for causal interrogation of circuit function in humans. However, it has been unclear whether the approach is potent enough to modulate behavior. To test this, we applied low-intensity ultrasound to a deep brain thalamic target, the ventral intermediate nucleus, in three patients with essential tremor. Brief 15-second stimulations of the target at 10% duty cycle with low-intensity ultrasound, repeated less than 30 times over a period of 90 minutes, nearly abolished tremor (98% and 97% tremor amplitude reduction) in 2 out of the 3 patients. The effect was observed within seconds of the stimulation onset and increased with ultrasound exposure time. The effect gradually vanished following the stimulation, suggesting that the stimulation was safe with no harmful long-term consequences detected. This result demonstrates that low-intensity focused ultrasound can robustly modulate deep brain regions in humans with notable effects on overt motor behavior.

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Section: Discussionmentioning

confidence: 99%

Noninvasive modulation of essential tremor with focused ultrasonic waves

Riis,

Losser,

Kassavetis

et al. 2024

J. Neural Eng.

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“…From the general point of view that stimulation occurs at the focal spot, if mechanical stress plays a major role (Yoo et al 2022), only the results calculated by RSF can explain both. In addition, from a study measuring time-averaged second-order pressure patterns occurring in standing waves, positive peak values appear at half-wavelength intervals (Kim et al 2022). Comparing the second-order pressure patterns from the three ARF equations, as shown in figure 11, only the second-order pressure calculated by RSF shows the positive peak values at half intervals of the wavelength.…”

Section: Arf For Stress Analysismentioning

confidence: 95%

“…Among different types of ARF, the force that is considered responsible for ultrasound neuromodulation in tissues is the Reynolds stress force (RSF) (Palmeri et al 2005, Kim et al 2022, which is an ARF applied directly to a medium that is being used, in addition to ultrasonic neuromodulation, in various fields such as ultrasound elastography Catheline 2016, Prieur andSapozhnikov 2017), acoustic streaming (Tang and Hu 2015, Tang et al 2017, Wu 2018, and acoustic tweezers (Mitri andFellah 2008, Baudoin andThomas 2020). Although it is a fundamental force acting on tissues, many studies have generally used a modified formula instead of RSF equation (Palmeri et al 2005, Nightingale 2011, Ye et al 2016, Prieur and Sapozhnikov 2017, Obara et al 2021.…”

Section: Introductionmentioning

confidence: 99%

Acoustic radiation force for analyzing the mechanical stress in ultrasound neuromodulation

Kim¹,

Lee²,

Firouzi³

et al. 2023

Phys. Med. Biol.

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Objective. Although recent studies have shown that mechanical stress plays an important role in ultrasound neuromodulation, the magnitude and distribution of the mechanical stress generated in tissues by focused ultrasound transducers have not been adequately examined. Various acoustic radiation force (ARF) equations used in previous studies have been evaluated based on the tissue displacement results and are suitable for estimating the displacement. However, it is unclear whether mechanical stress can be accurately determined. This study evaluates the mechanical stress predicted by various AFR equations and suggests the optimal equation for estimating the mechanical stress in the brain tissue. Approach. In this paper, brain tissue responses are compared through numerical finite element simulations by applying the three most used ARF equations—Reynolds stress force ((RSF)), momentum flux density tensor force, and attenuation force. Three ARF fields obtained from the same pressure field were applied to the linear elastic model to calculate the displacement, mechanical stress, and mean pressure generated inside the tissue. Both the simple pressure field using a single transducer and the complex standing wave pressure field using two transducers were simulated. Main results. For the case using a single transducer, all three ARFs showed similar displacement. However, when comparing the mechanical stress results, only the results using the RSF showed a strong stress tensor at the focal point. For the case of using two transducers, the displacement and stress tensor field of the pattern related to the standing wave were calculated only from the results using the RSF. Significance. The model using RSF equation allows accurate analysis on stress tensor inside the tissue for ultrasound neuromodulation.

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