Medtronic, Inc.

Sonic Innovations, Inc.

David A Wayne

Trevor A Blyth

Benjamin Edward Nise

Tho V Huynh

Jeff Ireland

Tho Huyhn

In a double-sided pulse width modulator, an amplifier has a first input connected to a first reference potential, a second input, and an output. A first bank of storage elements have a first terminal connected to the second input of the amplifier, and a second terminal. A first bank of switches have an output terminal connected to a second terminal of the storage elements, an input terminal, and a control terminal connectable by a timing gate to an output of the modulator and a polarity control bit for a first value to be input into the input terminals. A feedback storage element is connected in parallel with a first timing switch between the second input of the amplifier and the output of the amplifier. A comparator has a first input connected to a second reference potential, a second input, a timing enable input, and an output. A second bank of storage elements have a first terminal connected to the second input of the comparator, and a second terminal. A second timing switch is connected in parallel with a first one of the storage elements of the second bank of storage elements between the output of the amplifier and the second input of the comparator. A second bank of switches have a first terminal connected to one of the storage elements in the second bank of storage elements other than the one storage element, a second terminal connected to the output of the amplifier, and a control terminal connected to a second input value. A current source is connected to the second input of the comparator to discharge a value having a duration proportional to the product of the first input value and the second input value to form the output of the modulator at the output of the comparator.

Double-sided pulse width modulator

A battery impedance measurement apparatus for battery powered implantable medical apparatus in which current source means and reference impedance means are selectively connected across the battery after it has been isolated from the medical apparatus, and the resulting currents of interest are digitized to provide a factor directly related to the value of the internal impedance of the battery. The digitized value may be telemetered out of the implanted medical apparatus to enable critical decisions to be made based on the remaining life of the implanted battery. The same measurement apparatus can be used to form an accurate end-of-life signal.

Battery impedance measurement apparatus

An apparatus for and method of measuring the current which flows through a cardiac pacing lead to artificially stimulate contractions of the myocardium. This current measurement is useful for estimating battery life and monitoring proper operation of the pacing lead and the implantable pulse generator. The measurement is accomplished by carefully controlling the gain of the output amplifier and timing the rate of charge and discharge of the output capacitor. The average pacing current can be determined from the relative charge and discharge times given that the other circuit component values are known and controlled.

Growing community of inventors

Scottsdale, AZ, United States of America

David A Wayne