Arterial blood pressure monitoring devices, systems and methods using cardiogenic impedance signal

Abstract

Provided herein are implantable systems, and methods for use therewith, for monitoring a patient's arterial blood pressure. Electrode(s) implanting within and / or on the patient's heart are used to obtain a cardiogenic impedance (CI) signal indicative of cardiac contractile activity. Additionally, a signal (e.g., PPG or IPG signal) indicative of changes in arterial blood volume remote from the patient's heart is obtained using a sensor or electrodes that are implanted remote from the patient's heart. One or more metrics indicative of pulse arrival time (PAT) are determined, where each metric can be determined by determining a time from one of the detected features of the CI signal to one of the detected features of the signal indicative of changes in arterial blood volume. Based on at least one of the metric(s) indicative of PAT, arterial blood pressure is estimated, which can include determining values indicative of systolic blood pressure, diastolic blood pressure, pulse pressure and / or mean arterial blood pressure, and / or changes in such values.

Description

PRIORITY CLAIM[0001]This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 61 / 223,992, filed Jul. 8, 2009, entitled “Arterial Blood Pressure and Electromechanical Delay (EMD) Monitoring Devices, Systems and Methods” (Attorney Docket No. A09P3005), which is incorporated herein by reference.RELATED APPLICATIONS[0002]This application is related to the following commonly assigned applications, each of which is incorporated herein by reference: U.S. patent application Ser. No. 12 / 474,276, entitled “Standalone Systemic Arterial Blood Pressure Monitoring Device,” filed May 28, 2009 (Attorney Docket No. A09P3002); U.S. patent application Ser. No. 11 / 848,586, entitled “Implantable Systemic Blood Pressure Measurement Systems and Methods,” filed Aug. 31, 2007 (Attorney Docket No. A07P3032); U.S. patent application Ser. No. 12 / ______, entitled “Arterial Blood Pressure Monitoring Devices, Systems and Methods for use while Pacing,” filed the same day as...

AI Technical Summary

Benefits of technology

[0014]Certain embodiments of the present invention related implantable systems, and methods for use therewith, for monitoring a patient's systemic arterial blood pressure. One or more electrodes implanting within and/or on the patient's heart are used to obtain a cardiogenic impedance (CI) signal indicative of cardiac contractile activity. Additionally, an implanted sensor or implanted electrodes, remote from the patient's heart, are used to obtain a signal indicative of changes in arterial blood volume remote from the patient's heart. In an embodiment, an implanted photoplethys

Problems solved by technology

However, such an approach is slow, requires the intervention of a skilled clinician and does not provide timely readings as it is a measurement at only a single point in time.

While systolic blood pressure and diastolic blood pressure can also be obtained in more automated fashions, it is not always practical to obtain measures of pressure using a cuff and pressure transducer combination, especially if the intention or desire is to monitor systemic arterial blood pressure on a chronic basis.

However, an intravascular device may cause problems, such as, embolization, nerve damage, infection, bleeding and / or vessel wall damage.

There are a number of disadvantages to the Finapres technique.

Further, maintaining continuous cuff pressure causes restriction of the circulation in the finger being used, which is uncomfortable when maintained for extended periods of time.

Accordingly, the Finapres technique is not practical for chronic use.

Additionally, because of the need for a pneumatic cuff, a Finapres device can not be used as an implanted sensor.

Simple external blood pressure monitors also exist, but they do not offer continuous measurement and data logging capability.

Additionally, portable external miniature monitors that automatically log blood pressure data exist, but these devices can only store a day or so of data and require clinician interaction to download and process the measured data.

This delay is partly due to the time required for the contractile elements of muscles to stretch the series elastic components.

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