Heart therapy apparatus with therapy correction means

Details Heart therapy apparatus with therapy correction means Heart therapy apparatus with therapy correction means

1998-12-28

2001-01-30

Schaetzle, Kennedy (Department: 3762)

Surgery: light, thermal, and electrical application

Light, thermal, and electrical application

Electrical therapeutic systems

C607S005000, C607S002000, C607S014000

Reexamination Certificate

active

06181966

ABSTRACT:

The invention relates to a heart therapy apparatus comprising: detection means for detecting a physiological parameter that characterizes the state of the heart/circulatory system; comparison value storage means for storing a plurality of comparison values for the physiological parameter; comparator means, which are connected on the input side to the detection means and the comparison value storage means, for comparing the detected values to the stored values and for issuing a classification signal as a result of the comparison; therapy-storage means for storing a plurality of potential therapies for a heart (H); therapy means for selectively realizing one of the potential therapies; therapy registration means for registering a therapy that has been realized; and, therapy selection means, which are connected on the input side to the output of the comparator means and the therapy registration means, for selecting one of the stored therapies and activating the therapy means in dependence on the classification signal and the storage content of the therapy registration means.--.
Arrhythmias are known to manifest themselves in an extraordinary number of different forms. In recent years, an essential portion of the efforts spent on research and development in the field of implantable pacemakers and defibrillators was dedicated to the reliable detection of qualitatively different arrhythmias, requiring different therapies, and to the coordination of these with therapies that are adequate for the actual conditions.
The most important criteria for differentiating between different arrhythmia conditions continue to be the rate criteria, meaning the level and, if necessary, also the development over time (stability, monotony, etc) of the frequency of ventricular and atrial cardiac actions. Increasingly, additional data concerning the condition and/or the case history of the patient are also taken into account to arrive at an adequate therapy based on the rate criteria.
Thus, in the EP 0 580 128 A2, the rate criteria for the pacemaker therapy of pathological tachycardias are modified in dependence on a status signal that characterizes the actual physical activity of the patient and is obtained by means of an activity sensor. The respective algorithm is invalidated when primary atrial fibrillation is detected.
With a combination cardioverter/defibrillator (ICD=implantable cardioverter/defibrillator) and pacemaker unit, as disclosed in the EP 0 360 412 A1 (in continuation of a classification model with rigid range limits), the heart rate continuum is subdivided into several sub-ranges with variable limits. The actually used therapy for the limit ranges is selected from a store of therapies, which are predetermined for specific sections, by taking into account the case history, specifically the preceding rate development over time.
It is suggested in the EP 0 538 996 A1 that a different rate criterion be used for the initial detection of a tachyarrhythmia be different than that used for a confirmation detection at a later point in time. This is designed to take into account the physiological findings that (1) tachyarrhythmias that basically require therapy will relatively often end spontaneously and without stimulation intervention, but that (2) therapy will increasingly become necessary with longer-lasting tachycardias.
The reference U.S. Pat. No. 5,836,971 of the generic type proposes that various rate ranges for an ICD are dynamically associated with various therapies, which differ in the amount of energy used, in dependence on whether a previous therapy attempt took place and the level of energy used for this attempt. This is designed to ensure implementation of the principle of using increasing energy amounts during successive therapy attempts, even if a lower rate than the previous one adjusts itself following a shock, without the heart having returned to the normal sinus rhythm.
It is the object of the invention to provide an improved heart therapy apparatus of the generic type, which permits a more careful therapy of tachyarrhythmias.
SUMMARY OF THE INVENTION
The above object is solved according to the present invention with a heart therapy apparatus that comprises: detection means for detecting a physiological parameter that characterizes the state of the heartcirculatory system; comparison value storage means for storing a plurality of comparison values for the physiological parameter; comparator means, which are connected on the input side to the detection means and the comparison value storage means, for comparing the detected values to the stored values and for issuing a classification signal as a result of the comparison; therapy-storage means for storing a plurality of potential therapies for a heart (H); therapy means for selectively realizing one of the potential therapies; therapy registration means for registering a therapy that has been realized; therapy selection means, which are connected on the input side to the output of the comparator means and the therapy registration means, for selecting one of the stored therapies and activating the therapy means in dependence on the classification signal and the storage content of the therapy registration means; and, therapy correction means that are coordinated with the therapy selection means for delaying or inhibiting the realization of a therapy associated with the classification signal, or any therapy at all, or for changing the therapy associated with a classification signal in dependence on the classification signal and the memory content of the therapy registration means in claim
1
.
The invention includes the realization that changes in a variable characterizing the heart condition, particularly heart rate changes, following a therapy attempt for determining the further therapy course should be evaluated differently, even if the therapy attempt did not result in a return to the normal condition. Particularly when detecting specific changes, it may be appropriate to turn away from the principle of electrotherapy with increasing energy use or to stop further therapy attempts.
For an ICD, for example, it means that when detecting a rate drop following a defibrillator shock, no further therapy attempts will take place, even if the rate is still within a tachycardia range to which a therapy is assigned.
The invention provides for means to detect a physiological parameter, which characterizes the condition of the heart/circulatory system, for storing a multitude of comparison values for the physiological parameter and for comparing the detected values with the stored values in order to issue a classification signal. The invention also includes existing means for storing a plurality of potential therapies, means for selectively realizing one of the potential therapies, means for registering a previously realized therapy, and means for selecting one of the stored therapies in dependence on the classification signal. Special means are provided here for delaying the implementation of or for inhibiting the therapy associated with the actually present classification signal—or any therapy—in dependence on the classification signal and the previously executed therapy (to be more exact: a therapy attempt).
A special embodiment of the therapy apparatus, an implantable cardioverter/defibrillator (ICD) or combination pacemaker/defibrillator, comprises a shock pulse generator for the cardioversion or the defibrillation of the heart. Following a preceding shock pulse, it is designed to delay or inhibit additional shock pulses upon receiving a first classification signal, which indicates a heart rate with increased sinus rhythm. (With a combination pacemaker/defibrillator, it is possible in that case to activate an anti-tachycardia stimulation as well. However, this may not make sense physiologically.) The apparatus is otherwise designed to trigger additional shock pulses with essentially the same energy level, following an initial pulse, when receiving a second classification signal, which specifically indicates a heart rate in the

Affiliated with

Also associated with

Rating

Heart therapy apparatus with therapy correction means does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Heart therapy apparatus with therapy correction means, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heart therapy apparatus with therapy correction means will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2452853