Rate responsive active implantable medical device such as a pacemaker, defibrillator and/or cardiovertor, including the multisite type

• US 6,246,910 B1
• Filed: 06/23/1999
• Issued: 06/12/2001
• Est. Priority Date: 06/26/1998
• Status: Expired due to Term

• Current Assignee: Sorin CRM SAS (MicroPort Scientific Corp.)
• Original Assignee: Ela Medical S.A. (LivaNova Plc)
• Inventors: Limousin, Marcel, Bonnet, Jean-Luc
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US09/339,359
• Time in Patent Office: 720 Days
• Field of Search: 607/18, 607/17, 607/19, 607/20, 607/21, 607/22, 607/23
• US Class Current: 607/18
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A rate responsive active implantable medical device having at least one effort sensor, measuring a parameter which is predominantly physiological (VE) and delivering an output signal which is a function of the effort developed by a patient carrying the device, and at least one activity sensor, measuring a parameter which predominantly physical. The devices operates to (a) measure periodically at the two sensors “couples of values” (12, 14, 16; 22, 24, 26) corresponding to a given level of effort developed by the patient; (b) establish a characteristic function of the measured couples of values (10, 20), and (c) evaluate over the course of time this established characteristic, by seeking a possible increase in the signals delivered by the effort sensor as compared to the signals delivered by the activity sensor, indicative of the patient'"'"'s metabolic demand (cardiac output requirements). The device preferably is implemented in a multisite type pacemaker in which the control of stimulation and/or the configuration of the stimulation sites is modified in the even of an excessive increase in the metabolic demand of the patient.

Claims

1. A rate responsive active implantable medical device for use in a patient, comprising:

at least one effort sensor operable to measure a predominantly physiological parameter of a patient and having an output signal corresponding to an effort level of the patient;

at least one activity sensor operable to measure a predominantly physical parameter of patient and having an output signal corresponding to an activity level of the patient;

means for analyzing the at least one effort sensor output signal and the at least one activity sensor output signal, said means comprising;

means for periodically measuring said at least one effort sensor output signal and at least one activity sensor output signal and determining therefrom couples of values, each said couple of value corresponding to a given level of effort and activity developed by the patient at said measurement;

means for establishing a characteristic function of said determined couples of value for a first time period;

means for comparing an established characteristic function corresponding to a time period to a subsequent established characteristic function corresponding to a subsequent time period;

means for determining whether there is an evolution of said established characteristic function in response to at least one of said comparisons of an established characteristic function to a subsequent established characteristic function; and

means for determining a degree of deterioration of the patient in response to said evolution of said established characteristic function.

2. The device of claim 1 wherein the means for determining whether there is an evolution further comprises means for determining an increase in the effort sensor output signals relative to the corresponding activity sensor output signals of said couples of values.

3. The device of claim 2 wherein the means for determining whether there is an evolution further comprises means for determining an increase in the effort sensor output signals relative to the corresponding activity sensor output signals of said couples of values, wherein said activity sensor output signals correspond to the same patient activity level.

4. The device of claim 2, wherein the rate responsive device has a programmable function, and wherein the analyzing means further comprises:

means for comparing the increase in the effort sensor output signals relative to the activity sensor output signals to a predetermined threshold;

means for indicating the programmable function should be modified in response to said increase exceeding said predetermined threshold.

5. The device of claim 4 wherein the analyzing means further comprises means for modifying the programmable function in response to said indicating means.

6. The device of claim 5, further comprising:

at least a first electrode and a second electrode to be placed in corresponding distinct myocardial stimulation sites;

first means for controlling the stimulation of the distinct myocardial sites;

second means for controlling the configuration of the electrodes for stimulating the distinct myocardial sites;

wherein the modifying means further comprises means for modifying one of the first controlling means and second controlling means to modify one of the stimulation of and the configuration of the distinct myocardial sites to be stimulated in response to said increase exceeding said predetermined threshold.

7. The device of claim 1, wherein the means for determining whether there is an evolution further comprises means for detecting a shift in the established characteristic function in a direction of increasing patient effort.

8. The device of claim 1 wherein the means for establishing a characteristic function further comprises means for determining a slope of the activity sensor output signal relative to the effort sensor output signal, and wherein the means for determining whether there is an evolution further comprises means for determining an increase in the determined slope.

9. The device of claim 1 further comprising means for regularly periodically causing the means for determining whether there is an evolution to determine whether there is an evolution.

10. The device of claim 9 wherein the means for regularly periodically causing causes the means for determining whether there is an evolution to determine whether there is an evolution daily.