1. Field of the Invention
The invention relates to an apparatus for rejection diagnostics after organ transplantations.
2. Background Art
As regards the background of the present invention, a main post transplantation problem resides in a possible rejection of the transplanted organ due to a corresponding defense reaction of a patient's body. For this to be prevented, medicinal immunosuppression is carried out, which is meant to suppress the rejection reactions.
This medicinal immunosuppression has considerable side effects so that patient after-care is always accompanied with the conflict of too high an immunosuppression--and the possibly lethal consequences of an infection--and too low an immunosuppression--having the possibly lethal consequences of an acute rejection reaction. For these reasons, the tendency is to manage with minimum base therapy and to diagnose possible rejection episodes at an early stage, which can then still be parried by an immediately increased dose of drugs. For this type of therapy to be put into practice, a method must be available which permits the rapid diagnosis of a rejection reaction. To date, biopsy is customary in this regard, tissue being taken micro-invasively from the transplanted organ and then being examined hisologically. It is possible to infer from the result of these histological examinations that rejection reactions are to be expected.
A drawback of such a biopsy control resides in the fact that it is rather complicated and costly. Biopsies have to take place at a rhythm ranging between two weeks and two months, this meaning that each time, a micro-invasive operation is necessary, which is troublesome to the patient.
Approaches to solve these problems consist in that electric signals of reaction to stimulus of the transplanted organ are analyzed, from which conclusions are made, regarding the latter's condition and any possible rejection reaction. However, this is not an established method of diagnosis so far and it can only be used in the case of transplanted hearts, only hearts manifesting corresponding signals of reaction to stimulus. Consequently, other transplantation organs cannot be monitored. Moreover, another drawback resides in that a complete heart-pacemaker systems comprising ECG telemetry must be implanted for this method of diagnosis to be possible. Such heart-pacemaker systems have some size owing to the integrated battery and they have only a limited lifetime. Once the battery is exhausted, the heart-pacemaker system must be replaced, which does not predestine it to long-term use in diagnostic rejection investigation.