Abstract: Apparatus and methods for focusing transcranial ultrasound. The systems described herein are advantageous for noninvasive neuromodulation and other transcranial ultrasound applications such as high intensity focused ultrasound (HIFU). In particular, described herein are compound acoustic lens apparatus having a short focal length for use with a transcranial ultrasound system, systems including methods of using them. These compound lens assemblies allow transcranial stimulation of even superficial cortical regions of the brain for ultrasound neuromodulation with a compact, single transducer element system at low (e.g., 0.2 to 1 MHz) frequencies with relatively large diameter (e.g., >15 mm) transducers applying 1 to 10 watts/cm2 of acoustic energy (spatial-peak, temporal-average intensity at the target brain region), and short focal length (e.g., between 15 and 35 mm).

Abstract: A system for transcranial electrical stimulation comprises a processor having instructions of a computer model that can be adjusted to the head subject in response to one or more input parameters. The adjustable model may comprise a plurality of structures that can be adjusted to the head of the subject in response to parameters that can be readily measured, such as head size and head shape. Discrete brain regions can be stimulated with a plurality of electrodes arranged to stimulate the targeted region with decrease stimulation of the non-targeted regions in order to improve subject comfort. In many embodiments the plurality of electrodes comprises a montage of electrodes, and the targeted location is identified on the adjustable model and the number of electrodes, locations and pulse parameters determined in response to the adjustable model. The adjustment can be helpful to align structures of model with structures of the subject.

Abstract: Described herein are devices, systems, and methods for transdermal electrical stimulation. Devices described herein can include self-contained, lightweight, and wearable components. The devices include a primary unit including a first transdermal electrode and a secondary unit including a second transdermal electrode. The device can be capable of wireless communication. The primary unit and secondary unit are placed at two locations on the skin of a user, for example on the head or neck of a user. The first and second transdermal electrodes are electrically connected. Electrical stimulation is driven between the two electrodes. The electrical stimulation induces a cognitive effect in a user of the device.

Abstract: Described herein are devices, systems, and methods for transdermal electrical stimulation. Devices described herein can include self-contained, lightweight, and wearable components. The devices include a primary unit including a first transdermal electrode and a secondary unit including a second transdermal electrode. The device can be capable of wireless communication. The primary unit and secondary unit are placed at two locations on the skin of a user, for example on the head or neck of a user. The first and second transdermal electrodes are electrically connected. Electrical stimulation is driven between the two electrodes. The electrical stimulation induces a cognitive effect in a user of the device.