Abstract: Apparatus (11) for delivery of a medicament, drug or other therapeutic agent transdermally to a body by iontophoresis is provided. The apparatus (11) provides a means (13) for measuring and displaying the cumulative amount of the medicament delivered to the body by monitoring the amount of a metal, initially present at the anode (45), that is transferred to the cathode (41) in a subsidiary electrolyte cell (47) through which the drive current for the apparatus (11) passes. Optionally, the apparatus also provides a plurality of light emitting devices (63-1) that display a measure of the cumulative amount of medicament delivered, by use of visually distinguishable light colors or by use of binary encoding in the light display.

Abstract: Apparatus (11) for delivery of a medicament, drug or other therapeutic agent transdermally to a body by iontophoresis is provided. The apparatus (11) provides a means (13) for measuring and displaying the cumulative amount of the medicament delivered to the body by monitoring the amount of a metal, initially present at the anode (45), that is transferred to the cathode (41) in a subsidiary electrolyte cell (47) through which the drive current for the apparatus (11) passes. Optionally, the apparatus also provides a plurality of light emitting devices (63-1) that display a measure of the cumulative amount of medicament delivered, by use of visually distinguishable light colors or by use of binary encoding in the light display.

Abstract: A cell is provided which utilizes the electrochemical permeation technique to determine the hydrogen content of a metal. The working face of the cell has an opening into a cavity within the cell. A sponge for holding electrolyte fits in the cavity and an anode extends into the cavity. A contact is provided on the working face for contacting the metal being measured. When the cell is held against the metal being measured by the magnet which encloses the cell, a current caused by the oxidation of hydrogen permeating from the metal flows between the anode and the contact electrode. A circuit is provided to measure this hydrogen oxidation current and to calculate the hydrogen content based upon diffusion equations. A seal formed around the opening prevents leakage of electrolyte during the measurement and defines the area being measured.