Remus: System for Remote Deep Brain Interventions
Taylor D. Webb, Matthew G. Wilson, Henrik Odéen, Jan Kubanek
2021 · 10.1101/2021.05.05.442844
Abstract
Motivation Transcranial focused ultrasound brings personalized medicine to the human brain. Ultrasound can modulate neural activity or release drugs in specific neural circuits but this personalized approach requires a system that delivers ultrasound into specified targets flexibly and on command. Summary We developed a remote ultrasound system (Remus) that programmatically targets deep brain regions with high spatiotemporal precision and in a multi-focal manner. We validated these functions by safely modulating two deep brain nuclei—the left and right lateral geniculate nucleus–in a task-performing non-human primate. This flexible system will enable researchers and clinicians to diagnose and treat specific deep brain circuits in a noninvasive yet targeted manner, thus embodying the promise of personalized treatments of brain disorders. Animated graphical abstract: onetarget.us/download/rem .
Abstract via europepmc.
Exposures
Exposure 1: Left and right LGN, 650 kHz, 10%, 50% and 100% duty
Target: lateral geniculate nucleus — “left and right lateral geniculate nucleus”
Device: other named manufacturer · Doppler Electronic Technologies, Guangzhou, China · custom 256 element transducer ✓
| Waveform | continuous, pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 650 | ✓✓✓ |
| Pulse duration (ms) | not reported | ⚑ |
| Pulse repetition frequency (Hz) | 500 | ✓✓✓ |
| Duty cycle (%) | 10, 50, 100swept | ✓✓✓⚑ |
| Sonication duration (s) | 0.3 | ✓✓✓ |
| Free-field pressure (kPa) | 2,400 | ✓✓✓⚑ |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | not reported | |
| In-situ estimate | measurementsingle value | |
| In-situ pressure (kPa) | 650, 770swept | ✓✓✓⚑ |
| In-situ Isppa (W/cm²) | not reported | |
| In-situ Ispta (W/cm²) | not reported |
A 300 ms stimulus was delivered 150 ms before fixation point offset, into the left or right LGN every 6-14 s, side randomised, interspersed with no-ultrasound trials. Stimuli were either continuous (100% duty) or pulsed at 10% duty with a 500 Hz PRF; a 50% duty condition is mentioned in the supplement without PRF.
Flags from extraction
exposures[0].in_situ.pressure_kpa— Pressure at target was estimated from MR thermometry (heating of the focus), recorded here as method measurement. The figure legend gives 750 kPa; the Methods give 770 kPa (right LGN) and 650 kPa (left LGN).exposures[0].free_field.pressure_kpa— Hydrophone free-field pressure at the same input voltage; the paper does not state whether the waveform was pulsed or continuous for this measurement.exposures[0].timing.duty_cycle_pct— 50% duty appears only in the supplementary figure legend; PRF and pulse duration are stated only for the 10% condition.exposures[0].timing.pulse_duration_ms— Not stated; the paper gives only duty cycle and PRF.auditory_control— No auditory control was run; the authors argue from the left/right and waveform specificity of the effect that an auditory artefact is unlikely.sham_type— Trials without ultrasound were randomly interspersed within sessions; there was no separate sham arm.exposures[0].device.family— Custom transducer credited to Doppler Electronic Technologies; driven by a Verasonics system (named in the Software section).