Ultrasound modulation of brain activity

An untethered, wearable brain regulation interface device for modulating brain activity of a user using ultrasound, the device comprising:

• a wearable structure configured to be placed adjacent to the head, on the head or to cover at least a portion of the head of the user;
• at least one ultrasonic transducer coupled to the wearable structure and configured to emit ultrasound energy, wherein the at least one ultrasonic transducer is configured to deliver the ultrasound energy to a target tissue site in the user's brain;
• a piezo actuator configured to change a shape and/or a position of the at least one ultrasonic transducer;
• a controller coupled to the at least one ultrasonic transducer and the piezo actuator, the controller configured to drive the at least one ultrasonic transducer to deliver transcranial pulsed ultrasound to stimulate one or more intact brain circuits with a predominantly non-thermal, mechanical mechanism of action, wherein the controller is further configured to adjust a focus of the transcranial pulsed ultrasound by causing the piezo actuator to adjust the shape and/or the position of the at least one ultrasonic transducer;
• and
• a battery configured to provide power to the at least one ultrasonic transducer, the piezo actuator, and the controller;
• wherein the at least one ultrasonic transducer, the piezo actuator, the battery, and the controller are integrated within the wearable structure;
• and
• wherein the device is fully self-contained, does not require connection to an external imaging system or a remote processor, and enables ambulatory use.