Iontophoretic delivery device

An electrically powered iontophoretic delivery device for delivering an agent by iontophoresis comprising:

• a pair of electrode assemblies adapted to be placed on body tissue, at least one of the assemblies containing the agent to be delivered;
• a source of electrical power adapted to be electrically connected to the pair of electrode assemblies;
• a current generating circuit electrically connected to the electrode assemblies, the current generating circuit having substantially no power consumption when not activated;
• and
• an activation circuit comprising:
• a circuit path including the source of electrical power, the electrode assemblies and the body tissue, the electrode assemblies removable from the body tissue to open the circuit path;
• a sensing circuit electrically connected to the circuit path, the sensing circuit including a transistor which is activated when the electrodes are placed on the body tissue;
• and
• a turn-on circuit electrically connected to the sensing circuit, the turn-on circuit including a second transistor which activates the current generating circuit by causing current to flow to the current generating circuit when the transistor of the sensing circuit is activated;
• the activation circuit having substantially no power consumption when the circuit path between the electrodes is open.

An electrically powered iontophoretic delivery device for delivering an agent by iontophoresis including:

• a pair of electrode assemblies, at least one of the assemblies containing the agent to be delivered;
• a source of electrical power adapted to be electrically connected to the pair of electrode assemblies;
• and
• circuit means connecting the pair of electrode assemblies and the source of electrical power, the circuit means comprising:
• (a) a current generating circuit electrically connected to and under the control of a control circuit means, the current generating circuit adapted to apply current to the pair of electrode assemblies from said source of electrical power for delivering the agent, the current generating circuit having substantially no power consumption when disabled;
• and
• (b) the control circuit means for detecting the existence of a circuit between said electrode assemblies and disabling said current generating circuit in the absence of a circuit, the control circuit means having substantially no power consumption when deactivated.

A method of controlling an iontophoretic delivery device for delivering an agent by iontophoresis wherein the device includes a pair of electrode assemblies, at least one of the assemblies containing the agent to be delivered, a source of electrical power, and a current generating circuit adapted to apply current to the pair of electrode assemblies from said source of electrical power, said current generating circuit having substantially no power consumption when disabled, the method comprising the steps of:

• (a) providing a control circuit connected to the current generating circuit for controlling the current generating circuit and powering said control circuit using said source of electrical power;
• (b) activating the control circuit to detect the presence of a circuit between said electrode assemblies;
• and
• (c) the control circuit disabling said current generating circuit in the absence of a circuit between the electrode assemblies as detected in step (b).