Abstract: The disclosure relates, in part, to targeted drug delivery using an ultrasound procedure and, more particularly, to systems and methods for the measurement of levels of drug delivery and certain aspects of metabolism, such as drug metabolism, in the brain tissue.

Abstract: Systems and methods are provided for initializing an ultrasound procedure for a target region. The method includes determining a distribution of vessel diameters of vasculature in a target region. The method also includes providing, at the target region, microbubbles having a size distribution related to the distribution of vessel diameters.

Abstract: Apparatus and a method are presented for delivering a therapeutic substance to a subject. A therapeutic substance delivery device includes an ultraviolet radiation source that disinfects a disinfection chamber of the therapeutic device. Control circuitry (a) activates the ultraviolet radiation source to irradiate the disinfection chamber, (b) measures a current input to the ultraviolet radiation source, the current being indicative of intensity of the ultraviolet radiation within the disinfection chamber, and (c) terminates the activation of the ultraviolet radiation source at a time determined based on the measured current. Other embodiments are also described.

Abstract: Systems and methods for temporarily altering a tissue characteristic at a target region, such as the blood-brain barrier, include causing an ultrasound transducer to transmit acoustic energy to the target region at a transmission frequency; acquiring a cumulative harmonic response from at least the target region; and operating the transducer based at least in part on the acquired cumulative harmonic response.