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Biomedical subjects

H Thoma

Publications and source records attributed to H Thoma.

At least 73 records · Page 4Linked to original sources
PubMed1979

[The research programme "Artificial Heart" at the 2nd Department of Surgery, University of Vienna: a ten year review (author's transl)].

The experimental and clinical results are presented of the research programme "Artificial Heart" carried out by the 2nd Department of Surgery, University of Vienna. In particular, an assessment of the clinical experience in 177 patients with the intra-aortic balloon pump is documented and it is concluded that only limited cardiac support is possible by this pump. In view of this fact more efficient methods of mechanical circulatory support, such as the interaortic auxilliary ventricle, the aortic "Windkessel" ventricle with guiding balloon, and two types of ventriculo-aortic bypass ventricle were tested with regard to their haemodynamic and long-time efficacy. The transatrio-aortic auxilliary ventricle (E-LVAD) was also clinically tested in 11 patients. In conclusion the problems of total mechanical heart replacement are discussed.

Animals↗
PubMed1978

Clinical application of the ellipsoid left heart assist device.

The ellipsoid left heart assist device (E-LVAD) was implanted in eight patients suffering from intraoperative heart failure. It was not possible to remove these patients from extracorporeal circulation following an intracardiac procedure; therefore, implantation of the E-LVAD was performed during extracorporeal circulation. The inflow connector was pushed forward from a purse-string suture on the right superior pulmonary vein, across the mitral valve and into the left ventricle. The outflow connector was joined to the ascending aorta. In two patients, the artificial heart chamber was removed after complete recovery of the circulation; these patients, however, later died. In six other patients, untreatable right heart failure developed and these patients died with the pump in place. It is concluded, therefore, that the right heart must also be mechanically supported during postoperative heart failure.

Adult↗
PubMed1976

[Osseous bridging of the distraction gap in leg lengthening procedures (author's transl)].

The bony refill of the distraction-space in leg-lengthening operations is analysed by X-ray control and histological technic as well in animal experiments as clinical patients. Based on our observations a theory of the formation of bone is postulated: We figured out, that a) presumable besides the periosteal potentials of bone formation there are also other active mechanisms of bone growth to be found. b) frequently histological recognised formations of bones cannot yet be proved by X-ray, that means, that the X-ray changes follow the histological ones. c) optimal formation of callus needs most possible stability during the time of consolidation. d) most careful distraction prevents deformities.

Adolescent↗
PubMed1976

[A new design for a totally artificial heart: the ellipsoid heart (author's transl)].

Thromboembolic complications represent the main limiting factor in cardiac replacement by totally artificial hearts in calves at present. Thrombus formation within artificial hearts is caused by the appearance of stagnation areas. The ellipsoid heart eliminates stagnation areas by virtue of its production as a one-piece membrane. The heart is driven pneumatically and functions as a diaphragmatic blood pump. The stroke volume is 178 cm3 and the maximal cardiac output 15.8l/Min. Three acute experiments demonstrated a high degree of haemodynamic efficiency without compression of, or interference with surrounding structures, especially the inferior vena cava or the right atrium.

Animals↗
PubMed1976

[Clinical and experimental results with acupuncture-analgesia (author's transl)].

Operations under acupuncture analgesia have been performed in Vienna since March 1972. A total of 102 procedures has been performed with "classical" Chinese acupuncture analgesia. Additionally given analgesics, psychodynamic factors and neurophysiological components are of joint importance. Our success rate in these cases was 64 p.c. Since October 1972 we call "two-phase-acupuncture-analgesia". Up to June 1975 72 operations were performed under some modifications of this method. In a neurophysiological study 17 volunteers and in 2 patients undergoing stereothalamotomies depression or even disappearance of evoked potentials was be observed during acupuncture with alectrical stimulation. Thus an interaction between pain stimuli and acupuncture stimuli in the thalamus could for the first time be demonstrated in man.

Acupuncture Therapy↗
PubMed1976

[On the application of electric stimulation currents in operations. Concept of a clinically applicable device (author's transl)].

With the use of high voltage electric currents in patients who initally have been anaesthetised, the anaesthesiologist faces new aspects. For this reason basic principles of physical medicine and medical engineering with respect to special problems are described. The majority of impulses current generators used so far do not even comply with the first principal requirement of any therapy namely knowledge of the dose of the agent applied. A system for electric currents crossing the body is outlined, which is characterized by constant current and isovoltage-free outlets in connection with a special ECG-amplifier and a control pattern. This apparatus for the first time guarantees maximal safety in clinical use. First animal experiments demonstrate the possibility of the risk if this method is applied in a inexperienced manner: in all animals ventricular fibrillation could be achieved when the electrodes were used in a position near the heart and there appeared to occur nonspecific reactions when current was directed through the brain (ear acupuncture)

Acupuncture Therapy↗
PubMed1975

[The influence of acupuncture analgesia on the sensation and feeling of pain and the autonomic state of the organism (author's transl)].

This study reports the effect of acupuncture on the sensation of pain, feeling of pain and on the autonomic state of the organism. In order to elucidate the problem physiological and psychological parameters were employed. It was observed that the insertion of the needles with electrical stimulation raised the pain threshold. The rise occurred whether a classical acupuncture point or a placebo acupuncture point was used. When the pain was assessed subjectively, it was found that the needling of a classical acupuncture point favourably influenced the experience of pain. Furthermore, persons in whom acupuncture worked well were characterized by a low subjective and objective pain threshold, a slow pulse rate and a high anxiety score.

Acupuncture Therapy↗
PubMed1975

Telemetric ECG data (biorhythms) in operations with acupuncture analgesia in the People's Republic of China.

During seven operations with acupuncture analgesia in the People's Republic of China, recordings were made with a self-developed device for telemetric transmittance of the ECG. Among others, the amplitude of the QRS complex as well as the period of time between two cardiac cycles were electronically measured and registered for evaluation. Through comparison of the values from China with our own material, the following statements can be made: (1) All patients were in conditions ranging from restlessness and slight excitation to weariness and drowsiness. A condition similar to narcosis must be excluded. (2) In a large number of cases a preoperatively performed strong psychological sedation through pharmacological agents can be excluded with certainty. (3) The massive reaction to events such as the cleansing of the operative field refutes-at least partly-our concept of "Asiatic indifference". (4) Acupuncture cannot depress reflexes. (5) Finally, the hypothesis that acupuncture has a stabilizing effect on the circulation is invalid.

Acupuncture Therapy↗
PubMed1975

[Telemetric ECG data (biorhythms) during operations under acupuncture analgesia in the People's Republic of China (author's transl)].

On an educational journey to China, we were able to record and accumulate electrocardiograms during operations under acupuncture analgesia with the aid of a self-developed apparatus. To elaborate this among others the amplitude of the QRS-complex as well as the time period between two cardiac cycles were electronically measrued and registered. With examples from the comprehensive material it is possible to draw the following conclusions: 1. The patients were in conditions ranging from restlessness and irritation to weariness and drowsiness. A condition similar to that resulting from narcosis must be excluded. 2. A pre-operatively undertaken strong psychological sedation by means of drugs can be excluded with certainty. 3. The massive reaction to events such as the washing out of the operative field refutes, at least partly, our concept of "Asiatic indifference". 4. Acupuncture is not able to depress reflexes. 5. Finally, the hypothesis that acupuncture has a stabilizing effect on the circulation is not valid.

Acupuncture Therapy↗
PubMed1975

[Partial replacement of the heart].

A ventricular-aortic blood pump was constructed for the functional replacement of the left heart. Hemodynamic experiments showed that the device was able to pump the total cardiac output in calves with a body weight under 85 kg. In these cases the myocardial oxygen consumption decreased to 40%. Laboratory findings in 5 longterm experiments revealed a complete adaptation of the body to the artificial organ up to 73 days.

Animals↗