Predictive diagnosis of a patient's status in an active implantable medical device notably for cardiac pacing, resynchronization, defibrillation or cardioversion

Abstract

An active implantable medical device, notably a device for pacing, resynchronization defibrillation and/or cardioversion, and/or a device for diagnosing patient conditions, having a predictive diagnosis of the patient's status. The device measures a physiologic parameter, notably the minute ventilation (MV); measures a physical parameter, notably the acceleration (G); discriminates between phases of activity and rest of the patient; and includes a memory containing a plurality of fields selectively updated by statistical processing. These fields are comprising one first set ( 22 ) containing data related to the patient's activity phases, and one second set ( 24 ) containing data related to the patient's rest phases. The statistical processing is updating in a dissociated manner the first and second sets of fields, selectively as a function of the value taken by the status indicator, and the analysis ( 26 ) evaluates at least one clinical status index ( 28, 30, 32 ) based upon the data contained in the fields of both first and second sets.

I claim: 
     
         1 . An active implantable medical device of the pacing, resynchronization, defibrillation, cardioversion and/or, diagnosis, type comprising:
 means for measuring a predominantly physiologic corporal parameter of a patient and providing a physiologic signal;   means for measuring a predominantly physical corporal parameter of the patient and providing a physical signal;   means for discriminating between phases of rest and activity of the patient, operating in response to said physiologic and physical signals, and providing an indicator representative of the patient's status,   a memory containing a plurality of fields, and   means for statistical processing, able to receive as input, said physiologic and physical signals and status indicator, and able to provide as output processed information and selectively update said memory fields based upon said processed information,   wherein, said memory fields comprise:   a first set of fields containing the data related to the patient's activity phases, and   a second set of fields containing the data related to the patient's rest phases,   wherein said means for statistical processing are updating in a dissociated manner said first and second sets of fields, selectively as a function of the patient's status indicator, and   the device further comprising means for analysis able to evaluate at least one clinical status index based upon the data contained in the memory fields of both the first and second sets of fields.   
     
     
         2 . The device of  claim 1 , wherein:
 the first set of memory fields comprises fields that are representative of the elapsed duration in activity (T act ) and of the level of physiologic (MV) and physical (G) signals over said elapsed duration in activity, and   the second set of fields comprises fields that are representative of the elapsed duration at rest (T rep ) and of the level of the physiologic signal (MV) over said elapsed duration at rest.   
     
     
         3 . The device of  claim 2 , wherein the field of the first set representative of the level of the physical signal is a field containing an accumulation (ΣG i ) of the successive digitized values of the physical signal over a predetermined duration, said accumulation being operated only when the status indicator indicates an activity phase of the patient. 
     
     
         4 . The device of  claim 2 , wherein the fields of respectively the first and second sets representative of the level of the physiologic signal, are fields that contain an average (MV act ; MV rep ) of the successive digitized values of the physiologic signal over a predetermined duration, said average being updated only when the status indicator indicates respectively a phase of activity or rest of the patient. 
     
     
         5 . The device of  claim 1 , wherein the analysis means further comprises means for comparing at least some of said data to a reference value. 
     
     
         6 . The device of  claim 1 , wherein the analysis means further comprise means for comparing the variations of at least some of said data over a predetermined duration to a reference value. 
     
     
         7 . The device of  claim 5  wherein said reference value is a value calculated as a function of the average level taken by the corresponding datum over a predetermined duration. 
     
     
         8 . The device of  claim 7 , wherein the variation of said calculated reference value is bounded by high and/or low limits. 
     
     
         9 . The device of  claim 6  wherein said reference value is calculated as a function of the average level taken by the corresponding datum over a predetermined duration. 
     
     
         10 . The device of  claim 9  wherein the variation of said calculated reference value is bounded by high and/or low limits. 
     
     
         11 . The device of  claim 1 , wherein the analysis means are also able to evaluate at least one meta-index based upon the successive values taken by the clinical status index. 
     
     
         12 . The device of  claim 11 , wherein the device further comprises means for delivering a preventive alert, able to warn of an overshoot of a threshold by at least one of said meta-indices of clinical status evaluated by the analysis means. 
     
     
         13 . The device of  claim 11 , wherein said indices and meta-indices of clinical status are re-evaluated with a daily periodicity. 
     
     
         14 . The device of  claim 1  wherein the means for measuring a predominantly physiologic corporeal parameter further comprises a minute ventilation sensor. 
     
     
         15 . The device of  claim 1  wherein the means for measuring a predominantly physical corporeal parameter further comprises an acceleration sensor.