SYSTEM FOR ESTIMATING CARDIAC PRESSURE USING PARAMETERS DERIVED FROM IMPEDANCE SIGNALS DETECTED BY AN IMPLANTABLE MEDICAL DEVICE

• US 20080033498A1
• Filed: 08/20/2007
• Published: 02/07/2008
• Est. Priority Date: 01/11/2000
• Status: Abandoned Application

• Current Assignee: Brian Mann, James Whiting, Neal L. Eigler
• Original Assignee: Brian Mann, James Whiting, Neal L. Eigler
• Inventors: Whiting, James, Eigler, Neal, Mann, Brian
• Application Number:
  US11/842,109
• Publication Number:
  US 20080033498A1
• Time in Patent Office: Days
• US Class Current: 607/23
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/02156 Calibration means
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: A61B 8/04 Measuring blood pressure
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36564 controlled by blood pressure

Abstract

A method of monitoring pressure within a medical patient, includes measuring an actual pressure in a medical patient in a first time period; measuring an indicator of the actual pressure in the first time period, wherein the indicator is derived from an electrical signal of the patient'"'"'s heart; determining a correlative relationship between the actual pressure and the indicator, wherein both the actual pressure and the indicator are obtained in the first time period; measuring the indicator in a second time period; and determining the actual pressure in the second time period based on the correlative relationship obtained in the first time period and the indicator obtained in the second time period.

Claims

1. A system for estimating cardiac pressure within a patient using an implantable medical device, the system comprising:

an electrical field application system operative to apply an electrical field to tissues of the patient including cardiac tissues;

a measurement unit operative to measure a parameter influenced by the electrical field, the parameter being affected by cardiac pressure; and

a cardiac pressure estimation unit operative to estimate cardiac pressure within the patient by applying predetermined conversion factors to the measured parameter.

2. The system of claim 1 wherein the electrical field application system includes an impedance detection pulse generation system.

3. The system of claim 1 wherein the measurement unit includes:

an electrical impedance (Z) detector operative to detect an electrical impedance (Z) signal within the patient along a sensing vector wherein impedance is affected by cardiac pressure; and

a parameter determination unit operative to derive the parameter from the electrical impedance (Z) signal.

4. The system of claim 1 further including a heart failure detection system operative to detect heart failure based on estimated cardiac pressure.

5. The system of claim 1 further including an implantable warning device operative to generate a warning upon detection of heart failure.

6. A system for estimating cardiac pressure within a patient using an implantable medical device, the system comprising:

means for applying an electrical field to tissues of the patient including cardiac tissues;

means for measuring a parameter influenced by the electrical field, the parameter being affected by cardiac pressure; and

means for estimating cardiac pressure within the patient by applying predetermined conversion factors to the measured parameter.