Heart stimulating apparatus

Claim 2

In heart-pacing apparatus a first electrode implanted in a heart, a second electrode implanted in a heart, switching means operative to select either the first or the second electrode for controlling the apparatus, means electrically connecting the switching means and the first and second electrodes, means for supplying electrical pulses to the electrodes through the switching means and the electrical connection means, means for sensing the potential at either the first or the second electrode through the electrical connection means and the switching means, and further electrical connection means between thesensing means, the pulse supply means and the electrodes by which signals from the sensing means are operative to change over heart stimulation from one electrode to the other.

Claim 3

Apparatus according to claim 1 wherein the first electrode serves to stimulate one of the atria of the heart and the second electrode serves to stimulate one of the ventricles of the heart, and the switching means is controllable from externally of the body.

Claim 4

Apparatus according to claim 2, wherein the switching means comprises two switches, one of which determines the electrode to be connected to the pulse-supplying means of the apparatus and the other of which determines the electrode to be connected to the sensing of the apparatus.

Claim 5

Apparatus according to claim 1 wherein the first electrode serves to stimulate one of the chambers of the heart and the second electrode serves to stimulate the same chamber, both said electrodes being connected in the circuit of the sensing means through the electrical connection means and the switching means.

Claim 6

Apparatus according to claim 1, wherein the switching means is a semi-conductor switch of low resistance, and the apparatus further includes a detector, a counter and a decoder connected by the electrical connections to operate the semi-conductor switch.

Claim 7

Apparatus according to claim 1 comprising second sensing means serving to sense feed-back from one of the said electrodes and arranged automatically to change-over the pacing action from one electrode to the other in the event of absence of a signal from said one electrode.

Claim 8

Apparatus according to claim 1, wherein the sensing means comprises a first sensing circuit connected through the switching means and the electrical connection means to receive a feed-back signal from one of the electrodes and to supply an output to the electrical pulse supply means, said pulse supply means including a timing circuit and an output circuit connected to receive pulses from the timing circuit and to supply one of the electrodes through the electrical connection means and the switching means and the apparatus further includes a second sensing circuit connected to control the switching means to change-over automatically the pacing mode.

Claim 9

In heart-pacing apparatus an energy source, a first electrode implanted in a heart for atrial stimulation thereof, a second electrode implanted in a heart for ventricular stimulation thereof; switching means operative to select either the first or the second electrode for controlling the apparatus, means electrically connecting the switching means and the first and second electrodes for transmitting signals to the electrodes and receiving signals from them, means for supplying, in any given operative state, electrical pulses to one of the electrodes through the switching means and the electrical connection means, means for sensing the potential at either the first or the second electrode through the electrical connection means and the switching means, and further electrical connection means between the sensing means, the pulse supply means and the electrodes by which signals from the sensing means are operative to change over stimulation from the atrial electrode to the ventricular electrode and vice versa.

Claim 10

In heart-pacing apparatus an energy source, a first electrode implanted in a heart for atrial stimulation thereof, a second electrode implanted in a heart for ventricular stimulation thereof; switching means operative to select either the first or the second electrode for controlling the apparatus, means electrically connecting the switching means and the first and second electrodes for transmitting signals to the electrodes and receiving signals from them, means for supplying, in any given operative state, electrical pulses to one of the electrodes through the switching means and the electrical connection means, means for sensing the potential at either the first or the second electrode through the electrical connection means and the switching means, and further electrical connection means between the sensing means, the pulse supply means and the electrodes by which signals from the sensing means are operative to change over stimulation from the atrial electrode to the ventricular electrode and vice versa.