Electro-therapeutic device

A hand held electro-therapeutic device for applying electrical stimuli to selected points of contact on the body of a user, the device having a search mode and a stimulation mode and comprising

• a casing which is holdable in the hand,
• mounted to the casing a first active electrode for making electrical contact with a selected point on the body and a second passive electrode disposed on the casing for making electrical contact with the hand,
• voltage applying means for applying, in said stimulation mode, an alternating voltage across the electrodes to apply electrical stimuli to the body, and
• resistance detecting means for detecting, in said search mode, when said first electrode is located at or near a low resistance point, said resistance detecting means applying a DC voltage across the electrodes and providing an audible signal representative of the resistance,
• wherein in said search mode said electrodes are connected across a DC power supply and in said stimulation mode said first and second electrodes are connected to a common point by means of respective first and second transistors, each transistor having a respective first or second diode connected there-across to allow current to flow between said electrodes in a first direction via the first transistor and second diode and in a second direction via the second transistor and first diode.

A hand-held electro-therapeutic device for applying electrical stimuli to selected points of contact on the body of a user, the device comprising

• a casing arranged to be held in the hand,
• mounted to the casing a first active electrode for making contact with selected point of the body and a second passive electrode disposed on the casing for making electrical contact with the hand, and
• resistance detecting means for detecting when the first electrode is located at or near a low resistance point on the body, and
• voltage applying means in the casing for applying a voltage across the electrodes to pass a current therebetween through the body of the user, wherein the voltage applying means comprises means for applying an alternating voltage between the electrodes to apply electrical stimuli to the body of the user, and includes a transformer having a centre-tapped primary winding, a capacitor connected to the centre-tap and an oscillator which alternately grounds either end of the primary winding to discharge the capacitor therethrough, the transformer also having a secondary winding with one end connected to one of the electrodes and another end connected to the other electrode by a pair of back to back transistors each having a diode connected thereacross.