Patent ID: 8155740

Claim:
A constant current pacing apparatus comprising: an H-bridge circuit comprising a high side and a low side, wherein the H-bridge circuit comprises first and second legs connected between the high side and low side thereof, wherein the first leg of the H-bridge circuit comprises first and second current switching elements and the second leg of the H-bridge circuit comprises at least a third current switching element, wherein a patient is connectable to the first leg of the H-bridge circuit between the first and second current switching elements and to the second leg of the H-bridge circuit, wherein one of the first and second current switching elements along with the third current switching element define a pair of current switching elements such that, when the constant current pacing apparatus is operational and the pair of current switching elements are selected, a pacing stimulus having a first polarity is applied to the patient; and a constant current source connected to the high side or the low side of the H-bridge circuit, wherein the constant current source comprises a voltage source and a controlled current output circuit connected between the voltage source and the H-bridge circuit, wherein, when the constant current pacing apparatus is operational, application of a control signal thereto representative of a pacing stimulus to be applied to the patient results in a constant current output applied to the H-bridge circuit based on a relationship defined by the controlled current output circuit between the control signal and the constant current output.