Wearable transdermal electrical stimulation devices and methods of using them

A two-part, adherently-attached, lightweight, wearable, and self-contained transdermal electrical stimulation device for inducing a cognitive effect in a subject, the device comprising:

• a low-profile primary unit having a housing at least partially enclosing:
• a power source,
• a wireless communications module,
• a current generator connected to the power source configured to apply a current at a frequency of greater than 640 Hz;
• a controller configured to receive stimulation instructions from a remotely located processor via the wireless communications module,
• a replaceable cartridge including a first transdermal electrode, wherein the replaceable cartridge connects directly onto an inner surface of the housing so that the first transdermal electrode is mounted on an outer surface of the housing, and
• a power supply access port on the inner surface of the housing, wherein the power supply access port is covered by the first transdermal electrode to prevent access when the first transdermal electrode is connected to the inner surface;
• and
• a secondary unit electrically connected to the primary unit by a cable extending from the housing, the secondary unit including a second transdermal electrode;
• wherein the primary unit is configured to be worn on the subject's head or neck and the secondary unit is configured to be independently attached to a second location on the subject so that the controller controls the current generator to drive stimulation at greater than 640 Hz between the first and second electrodes based on stimulation instructions received from the remotely located processor to induce a cognitive effect in the subject.

A method of inducing a cognitive effect in a subject, the method comprising:

• attaching a primary unit of a two-part, lightweight, wearable, and self-contained transdermal electrical stimulation device to a first location on the subject's head or neck so that a first electrode contacts the subject's skin, so that the primary unit does not extend further than 30 mm from the subject's skin, wherein the primary unit contains a power source, and a controller and wherein the first electrode is part of a cartridge connected on an inner surface of the primary unit so that the first electrode is mounted on an outer surface of the primary unit;
• attaching a secondary unit comprising a second electrode to a second location on the subject, wherein the secondary unit is electrically connected to the primary unit by a cable;
• and
• driving stimulation between the first and second electrodes at a current frequency of greater than 640 Hz to induce a cognitive effect in the subject, wherein a controller in the primary unit drives stimulation;
• and
• accessing a power supply access port on the inner surface by removing the first electrode, wherein the power supply access port is covered by the first electrode when the first electrode is connected to the inner surface.

A method of inducing a cognitive effect in a subject, the method comprising:

• coupling a disposable first electrode and disposable second electrode to an inner surface of a reusable primary unit of a lightweight and wearable transdermal electrical stimulation apparatus, wherein the disposable first electrode is coupled to the primary unit via an electrode connector on the inner surface of the primary unit so that the first electrode is mounted on an outer surface of the primary unit and in electrical communication with a controller in the primary unit, and wherein the second electrode is electrically connected to the controller via a cable;
• attaching the primary unit to a first location on the subject's head or neck so that the first electrode contacts the subject's skin, and so that the primary unit does not extend further than 30 mm from the subject's skin;
• independently attaching the second electrode to a second location on the subject so that the second electrode contacts the subject's skin;
• activating the controller to drive stimulation at a current frequency of greater than 640 Hz between the first and second electrodes to induce a cognitive effect in the subject, and
• accessing a power supply access port on the inner surface by removing the first electrode, wherein the power supply access port is covered by the first electrode when the first electrode is connected to the inner surface.