US 6,002,963 A · Multi-axial accelerometer-based sensor for an implantable medical device and method of measuring motion measurements therefor

Abstract

An improved sensor and related method for multi-axial measurement of motion for an implantable medical device is disclosed. The sensor has a wide variety of applications, including use as a cardiac wall motion sensor or a physical activity sensor. The sensor includes first and second conductors over which the motion measurements are made. A first transducer provides a first motion measurement indicative of sensor acceleration during a first phase, while a second transducer provides a second motion measurement indicative of sensor acceleration during a second phase. The first and second transducers are connected in parallel so as to provide the first and second motion measurements to an implantable medical device over the first and second conductors. The first and second phases are non-overlapping periods of time so that the motion measurements from each transducer are time division multiplexed. The sensor provides motion measurements that may either be compensated or uncompensated for temperature effects. In either case, the motion sensor uses fewer conductors than conventional sensors to deliver its measurements.

Claims26

Dependent claims

A two-conductor multiplexed motion sensor for use with an implantable medical device, wherein the implantable medical device includes circuitry for monitoring or stimulating cardiac activity, the sensor comprising:

a first conductor;
a second conductor;
a first transducing circuit for providing a first motion measurement indicative of sensor acceleration during a first phase, wherein the first transducing circuit provides the first motion measurement to the implantable medical device over the first and second conductors;
and
a second transducing circuit for providing a second motion measurement indicative of sensor acceleration during a second phase, wherein the second transducing circuit is connected in parallel to the first transducing circuit so as to provide the second motion measurement to the implantable medical device over the first and second conductors,
wherein the first and second phases are nonoverlapping periods of time.

3 more elements

a first conductor;
a second conductor;
a first transducing circuit including transducing material having an electrical characteristic that varies measurably when the material is subjected to mechanical stress, the first transducing circuit for providing a first motion measurement indicative of sensor acceleration during a first phase, wherein the first transducing circuit provides the first motion measurement to the implantable medical device over the first and second conductors;
a second transducing circuit including the transducing material for providing a second motion measurement indicative of sensor acceleration during a second phase, wherein the second transducing circuit is connected in parallel to the first transducing circuit so as to provide the second motion measurement to the implantable medical device over the first and second conductors, wherein the first and second phases are nonoverlapping periods of time;
at least one base member;
at least one mass;
at least one cantilever beam having a fixed end that is fixed to a corresponding base member, and a free end upon which is disposed a corresponding mass, wherein the transducing material is disposed on the at least one beam for providing a beam measurement indicative of acceleration experienced by the beam as the beam deflects.

4 more elements

In an implantable medical device including a motion sensor and circuitry for monitoring or stimulating cardiac activity, a method for providing motion measurements from the sensor to the implantable medical device, the method comprising:

providing a first motion measurement indicative of sensor acceleration to the implantable medical device during a first phase, wherein the first motion measurement is provided over first and second conductors from a first transducing circuit in the sensor;
providing a second motion measurement indicative of sensor acceleration to the implantable medical device during a second phase, wherein the second motion measurement is provided over the first and second conductors from a second transducing circuit in the sensor, the second transducing circuit being connected in parallel to the first transducing circuit,
wherein the first and second phases are nonoverlapping periods of time.

Dependencies are inferred from the claim text.

Multi-axial accelerometer-based sensor for an implantable medical device and method of measuring motion measurements therefor

Life of this patent

Multi-axial accelerometer-based sensor for an implantable medical device and method of measuring motion measurements therefor

Life of this patent

Abstract

Claims26