Active Implantable medical Devices, Notably for Pacing, Resynchronization, Defibrillation And/Or Cardioversion, Having Improved Diagnosis Of the Patient's Clinical Status

• US 20070150016A1
• Filed: 11/24/2006
• Published: 06/28/2007
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Original Assignee: Sorin CRM SAS
• Inventors: Casset, Cyrille
• Granted Patent: US 7,792,582 B2
• Time in Patent Office: Days
• 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: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

An active implantable medical device, preferably a device for pacing, resynchronization, defibrillation and/or cardioversion of a patient, that includes functionality that assists in the diagnosis of the patient'"'"'s clinical status. This devices comprises circuits (10, 12) for measuring one physiologic parameter, preferably minute ventilation (VE), and circuits (14, 16) for measuring a physical parameter, preferably acceleration (G), control logic (18) for discriminating between activity and rest phases of the patient, and analysis circuits (20-28), to process and combine these signals and memorize (store in memory) the obtained results in the form of a data history. The analysis will establish characteristics providing, for successive dates, representative values, for a given period of time, of the physical signal and physiologic signal during activity phases of the patient, and/or of the physiologic signal during rest phases. These circuits search for remarkable dates for each of the characteristics and allocate specific indices of clinical status respective to each of the periods comprised between the remarkable dates, then combined the specific thus obtained into one single composite index.

Claims

1. An active implantable medical device of the pacing, resynchronization, defibrillation and/or cardioversion type, or an active implant intended to diagnose a cardiac rhythm disorder, comprising:

means for measuring a predominantly physiologic corporal parameter and providing a physiologic signal representative thereof;

means for measuring a predominantly physical corporal parameter and providing a physical signal representative thereof;

means for discriminating a status of a patient as one of a phase of rest and a phase of activity, operating in response to said physiologic and physical signals, and for providing an index corresponding to the patient status;

means for analysis, responsive to the physiologic signal, the physical signal and the status index, and for memorizing the obtained results on the form of a data history;

wherein said means for analysis further comprise;

first means for establishing characteristics providing, for successive dates, representative values over a given period of time, of;

the physical signal during activity phases of the patient,

the physiologic signal during activity phases of the patient and/or

the physiologic signal during rest phases of the patient,

second means for searching for a plurality of remarkable dates for each of the characteristics thus obtained,

third means for allocating specific indices of clinical status respective to each of the periods comprised between said remarkable dates for each of the characteristics thus obtained, and

fourth means for combining into one composite index, said specific indices thus determined.

2. The device of claim 1, wherein said second means further comprise means for performing a multiple linearization, able to transform each characteristic into a continuous series of line segments, each segment having a pair of endpoints and a slope, said endpoints defining one of said remarkable dates for said characteristic.

3. The device of claim 2, wherein said means for performing a multiple linearization are means able to transform the characteristic into a continuous series of line segments whose endpoints are points of this characteristic.

4. The device of claim 2, wherein said means for performing a multiple linearization are iterative means operating through the application of a regression formula.

5. The device of claim 4, wherein said means for performing a multiple linearization define a remarkable date if the sum of the absolute values of the variances between said segment and said characteristic is above a first predetermined threshold value.

6. The device of claim 5, wherein said means for performing a multiple linearization define said remarkable date only if each of the variances between said segment and said characteristic are not exceeding a second predetermined threshold.

7. The device of claim 2, wherein said third means further comprise means for evaluating the slope of said line segments and allocating the corresponding specific index as a function of the value of said slope.

8. The device of claim 1, wherein said fourth means further comprise means for implementing a prerecorded truth table providing univalently, for each possible combination of specific indices, a corresponding value of composite index.

9. The device of claim 1, wherein said first means are establishing said characteristic based upon moving averages of the accumulated values of said physical signal during activity phases.

10. The device of claim 1, wherein said first means are establishing said characteristic based upon moving averages of the accumulated values of said physiologic signal during activity phases.

11. The device of claim 1, wherein said first means are establishing said characteristic based upon moving averages of the accumulated values of said physiologic signal during rest phases.

12. The device of claim 1, wherein said specific indices, and composite clinical status index, are re-evaluated with a given periodicity.