[Personalized medicine and individual healthcare : Medical and information technology aspects].

The individualization of medicine and healthcare appears to be following a general societal trend. The terms "personalized medicine" and "personal health" are used to describe this process. Here it must be emphasized that personalized medicine is not limited to pharmacogenomics, but that the spectrum of personalized medicine is much broader.

[Evaluation of PC-based radiologic diagnosis workstations].

Purpose: Evaluation of PC based Radiology Diagnostic Workstations performed by medical users using detailed lists of functional requirements.

Material And Methods: During February 1999 and September 1999 medical users at the hospital Dresden-Friedrichstadt Germany had tested 7 types of radiology diagnostic workstations. Two types of test methods were used: In test type 1 ergonomic and handling functions were evaluated impartial according to 78 selected user requirements.

Right ventricular conductance to establish closed-loop pacing.

Innovations in pacing technology, which include the addition of rate-responsive features to programmable pacemakers, can improve the quality of life of patients suffering from sick sinus syndrome. Among the strategies providing rate-adaptive cardiac pacing, the most attractive is the physiological restoration of closed-loop chronotropic control. This paper describes how autonomic nervous system (ANS) control information is extracted from dynamic measures of myocardial contractile performance obtained from unipolar conductance measurements using the stimulation electrode in the right ventricular cavity.

Autonomic nervous system controlled closed loop cardiac pacing.

A multicenter clinical study is presented, which focuses on the reestablishment of closed loop cardiac control in patients with chronotropic insufficiency. Using the information about sympathetic tone contained in the myocardial contractility, it is possible to reconnect the heart rate to the physiological control mechanisms. Intracardiac impedance is measured with the ventricular electrode and the ventricular inotropic parameter (VIP) is derived from that.

[Measuring intracardiac impedance for the determination of sympathetic nerve activity in frequency-adapted electrostimulation--Part 2: Clinical results].

The results of a multicenter clinical study involving patients receiving the first ANS controlled rate adaptive pacemaker are presented. In the patients with primary or secondary chronotropic insufficiency, it is possible to reestablish the closed loop control system that includes the baroreceptors, the medulla oblongata, the cardiac output and the mean arterial blood pressure. This system serves to keep the blood pressure constant in the face of changing demands on the circulation.

Improved rate responsive algorithm in QT driven pacemakers--evaluation of initial response to exercise.

The QT pacemaker is a rate modulated pacemaker that uses the evoked QT interval as an indicator to determine its optimal pacing rate. Despite the generally favorable clinical results with this form of pacing, some flaws in the system have been reported, such as the frequently observed rather slow initial response of the pacing rate to physical exercise, and the phenomenon of oscillation of the heart rate. These problems can be attributed to the rate adaptive algorithm used in the current QT pacemaker.

[Intracardiac recording of potentials in placing a thermodilution catheter].

It is reported on methods of positioning our former described flow directed thermodilution (TD) catheter by the intracardiac ECG derived from two electrodes, one at the tip of the catheter near the temperature sensor and the other six centimeter proximally of it. The typical criterion of the intracardiac ECG in the outflow tract of the right ventricle and in the pulmonary artery are listed, especially the amplitudes, the QRS-splits, T-wave inversion and P-wave configuration.

[Physiologic frequency adaptation of cardiac pacemakers using systolic time intervals].

Of the parameters in consideration for control of physiological rate responsive pacing special interest is directed to stroke volume. In search of indirect parameters which are correlated to stroke volume it is demonstrated on principle that systolic time intervals could be used. From the relation ejection time versus pre-ejection time (LVET/PEP) which is known for its correlation to stroke volume a simple algorithm is derived which is based on the realization that PEP is related to the reciprocal of cardiac output.

[A new catheter for hemodynamic studies].

It is reported on a new catheter technique for the determination of the cardiac output by means of the method of thermodilution. It consists of a thin sensorcatheter (3 Ch), which contains a microthermistor as temperature sensor and additionally two electrodes. The insertion of the catheter is carried out via puncture of the subclavian vein by means of a special introducer set, the outer sheath of which can used for injecting the cold solution.

[Possibilities for frequency adjusted heart stimulation].

In the sick sinus syndrome, in sinu-atrial conduction defects or in atrial flutter or fibrillation a stress-adapted, frequency-adapted stimulation cannot be obtained by the processing of the atrial potential. Here one depends on partly extracardiac parameters which contain informations about the metabolic and stress situation, respectively. A survey of the parameters for a frequency-adapted stimulation discussed at present is given and a critical valuation of them is carried out.

[Insertion behavior of miniature IBW-79 pressure transducers in the left heart].

It is reported on the properties of the new catheter-tip pressure transducer IBW-79 (Ch 5) for applications in the left heart. The approach to the left ventricle was carried out with the help of Seldinger-technique (Ch 10) via A. femoralis.

[For and against physiologic heart stimulation].

Issuing from the own experiences on 110 patients with a heart stimulation including the atrium, advantages and disadvantages as well as possibilities of a complication in physiological stimulation system are discussed. From the differential indications for the pacemaker therapy are derived. It is estimated that approximately 20% of the new implantations in critical indication should be performed by a form of physiological stimulation.

[Hysterosalpingography with simultaneous intrauterine pressure measurement. A contribution to invasive sterility diagnosis].

There will be demonstrated a method in order to contrast the cavum uteri and the uterine tubes by means of a x-ray TV amplifier in combination with simultaneous intrauterine pressure monitoring. We could demonstrate that measuring the intrauterine pressure during continuous flow of radio-opaque material at hysterosalpingography results in additional informations about tubal patency.

[Dynamics of the measurement of urethral pressure in the evaluation of the urethral stress profile].

To obtain exact recordings of the urethral stress profile a pressure rise rate greater than 150 kPa/s is necessary. In this point of view Micro-transducers are advantageous. The different perfusion methods can be improved by the aid of pneumatic-hydraulic infusion systems and low-compliance catheters.

[URO-103--a new uroflow measuring device].

A new uroflow measuring instrument produced in the GDR by W. Rentsch , the Uroflow -Recorder URO-103, is presented and compared with thermistor and capacity-measuring apparatuses. The Uroflow -Recorder gives strictly linear measurements and requires extremely little maintainence .

[Micro-tip transducer for simultaneous pressure and temperature measurements].

It is reported on a new semiconductor-microtransducer with integrated pressure and temperature sensor for simultaneous intracorporal pressure and temperature measuring. The properties of the pressure and temperature canal are described in short and first clinical applications (pressure measuring of the right heart, determination of cardiac output by means of thermodilution). Further applications are discussed.