title: A 200-1380-kHz Quadrifrequency Focused Ultrasound Transducer for Neurostimulation in Rodents and Primates: Transcranial In Vitro Calibration and Numerical Study of the Influence of Skull Cavity.
abstract: Low intensity transcranial focused ultrasound has been demonstrated to produce neuromodulation in both animals and humans. Primarily for technical reasons, frequency is one of the most poorly investigated critical wave parameters. We propose the use of a quadri-band transducer capable of operating at 200, 320, 850, and 1380 kHz for further investigation of the frequency dependence of neuromodulation efficacy while keeping the position of the transducer fixed with respect to the subject's head. This paper presents the results of the transducer calibration in water, in vitro transmission measurements through a monkey skull flap, 3-D simulations based on both a μ -computed tomography ( μ CT)-scan of a rat and on CT-scans of two macaques. A maximum peak pressure greater than 0.52 MPa is expected at each frequency in rat and macaque heads. According to the literature, our transducer can achieve neuromodulation in rodents and primates at each four frequencies. The impact of standing waves is shown to be most prominent at the lowest frequencies.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Constans
authors.forename: Thomas
authors.initials: T
authors.lastname: Deffieux
authors.forename: Pierre
authors.initials: P
authors.lastname: Pouget
authors.forename: Mickael
authors.initials: M
authors.lastname: Tanter
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Aubry
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004867:Equipment Design; D005260:Female; D008251:Macaca; D008297:Male; D051381:Rats; D012886:Skull / Q000502:physiology*; D014159:Transducers; D014464:Ultrasonic Therapy / Q000295:instrumentation*