A dual purpose biomedical device has a solid flexible ultrasonic couplant sheet or pad formed from an electrically conductive hydrogel. The hydrogel sheet has an upper surface that is exposed during use for allowing direct contact between an ultrasonic generator and the hydrogel sheet and a lower surface that is placed during use against the skin of a patient whereby the hydrogel sheet transmits ultrasonic waves to and from the body of the patient. An adhesive is operatively associated with the hydrogel sheet for adhering the sheet to the skin. A removable and replaceable electrically conductive flexible sheet is supported upon the upper surface of the hydrogel sheet for establishing electrical contact with the patient through the hydrogel sheet when lowered into contact with the hydrogel sheet. The conductive sheet is removable therefrom for allowing the ultrasonic generator to contact the hydrogel sheet.