US 8,007,442 B2Granted

Sensing rate of change of pressure in the left ventricle with an implanted device

AssigneeCardiac Pacemakers, Inc.

InventorsGerrard M. Carlson, Krzysztof Z. Siejko, Ramesh Wariar, Marina V. Brockway

Life of this patent

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Abstract

An implantable device and method for monitoring S1 heart sounds with a remotely located accelerometer. The device includes a transducer that converts heart sounds into an electrical signal. A control circuit is coupled to the transducer. The control circuit is configured to receive the electrical signal, identify an S1 heart sound, and to convert the S1 heart sound into electrical information. The control circuit also generates morphological data from the electrical information. The morphological data relates to a hemodynamic metric, such as left ventricular contractility. A housing may enclose the control circuit. The housing defines a volume coextensive with an outer surface of the housing. The transducer is in or on the volume defined by the housing.

Claims20

Dependent claims

A device comprising:

a transducer configured to convert an acceleration correlative to a S1 heart sound into an electrical signal;
a control circuit coupled to the transducer, the control circuit configured to receive the electrical signal, identify the acceleration correlative to the S1 heart sound, determine a maximum amplitude of the acceleration correlative to the S1 heart sound and a minimum amplitude of the acceleration correlative to the S1 heart sound, and determine a patient status indicator using an indication of a peak-to-peak difference between the maximum amplitude of the acceleration correlative to the S1 heart sound and the minimum amplitude of the acceleration correlative to the S1 heart sound, wherein the patient status indicator is correlative to at least one of contractility or a maximum time rate of change of pressure within a ventricle of a heart during a cardiac cycle, wherein the control circuit is configured to use an auxiliary physiological signal to select the accelerations used in the determination of the patient status indicator, the auxiliary physiological signal indicative of at least one of physical activity or respiration.

A method comprising:

using a transducer to detect an acceleration correlative to an S1 heart sound;
converting the acceleration correlative to S1 heart sound into an electrical signal using the transducer;
using the electrical signal to determine a maximum amplitude of the acceleration correlative to the S1 heart sound and a minimum amplitude of the acceleration correlative to the S1 heart sound;
and
determining a patient status indicator using an indication of a peak-to-peak difference between the maximum amplitude of the acceleration correlative to the S1 heart sound and the minimum amplitude of the acceleration correlative to the S1 heart sound, wherein the patient status indicator is correlative to at least one of contractility or a maximum time rate of change of pressure within a ventricle of a heart during a cardiac cycle, wherein an auxiliary physiological signal is used to select the accelerations used in the determination of the patient status indicator, the auxiliary physiological signal indicative of at least one of physical activity or respiration.

2 more elements

A non-transitory device-readable medium including instructions that, when performed by the device, comprise:

using a transducer to detect an acceleration correlative to an S1 heart sound;
converting the acceleration correlative to S1 heart sound into an electrical signal using the transducer;
using the electrical signal to determine a maximum amplitude of the acceleration correlative to the S1 heart sound and a minimum amplitude of the acceleration correlative to the S1 heart sound;
and
determining a patient status indicator using an indication of a peak-to-peak difference between the maximum amplitude of the acceleration correlative to the S1 heart sound and the minimum amplitude of the acceleration correlative to the S1 heart sound, wherein the patient status indicator is correlative to at least one of contractility or a maximum time rate of change of pressure within a ventricle of a heart during a cardiac cycle, wherein an auxiliary physiological signal is used to select the accelerations used in the determination of the patient status indicator, the auxiliary physiological signal indicative of at least one of physical activity or respiration.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/703,533Filed 10 Feb 2010 · continuation
Priority: 1 Jun 2005
Published: US 2010/0145403 A110 Jun 2010
Granted: 30 Aug 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

A61B 7/00
Instruments for auscultation
A61B 5/021
Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow: measuring…
A61N 1/36564
Controlled by a physiological quantity other than heart potential, e.g. blood pressure: controlled by blood pressure
A61N 1/36578
Controlled by a physiological quantity other than heart potential, e.g. blood pressure: controlled by mechanical motion of the heart wall, e.g.…

Family

Application11/142,851Parent of this continuation · filed 1 Jun 2005
US 2010/0145403 A1Pre-grant publication · published 10 Jun 2010
US 7,670,298 B2Parent of this continuation
US 2006/0276849 A1Published application
US 8,007,442 B2This patent

From the US filing history. Foreign family members aren’t listed.