[Exposure rates from 238Pu fueled nuclear battery for cardiac pacemaker (author's transl)].
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The design of a new three-state myoelectric control system is presented. This controller determines its operating state from the initial rate of increase of the myoelectric signal, and the concept is realized in great measure through digital logic techniques. Proportional control of both active states (same dynamic range) is a unique feature of the controller. A microcomputer was interfaced in a simple way with myoelectric potentials to simulate the three-state controller described and to simulate various other state-determined control methods (some multifunctional). This was found to be a valuable method of evaluating control schemes without building the actual devices.
An implant telemetry system for the simultaneous monitoring of temperature, activity, and EKG from small animals, such as rats, has recently been designed with the novel feature that instead of a battery the system is energized by an inductive field. A 250 kHz resonant coil surrounds the cage (30 X 30 X 20 cm) and provides the approximately 100 muW of power required to operate the implant transmitter while allowing the animal unrestrained movement in the cage. The implant can also be battery operated if desired RF transmission is in the 8-10 MHz band, which allows the use of a simple, essentially single IC chip, receiver.
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Fitting myoelectrically controlled hand prostheses to young children has previously been considered unrealistic and even contraindicated. In 1971 the first preschool child was supplied with a myoelectric prosthesis at the Regional Hospital in Orebro, Sweden. A total of 40 young unilateral below-elbow congenital amputee children have thus far been fitted. The youngest children were 16 months of age when fitted. Such prostheses are clearly better integrated and accepted by children than by most adults. However, certain condiderations must be taken into account: the stump parameters ought to be suitable and the fitting done by a skilled team; the training must be properly followed up in close cooperation with the parents, who should be thoroughly and adequately informed; possibilities of prosthetic adjustments and rapid repairs should be mentioned; and psychological factors must be carefully evaluated. Under these conditions a very early myoelectric prosthetic fitting can be expected to greatly benefit the individual.
Habilitation of the upper extremity limb-deficient child is enhanced when the treatment program is based on normal growth and development guidelines. Specific developmental tasks have been identified as key indicators of a child's readiness to benefit from prosthetic fitting, activation of major components, use training, and changes in prosthetic design such as modular prostheses and electric components. Use of developmental guidelines also enhances family support because their role in the program can be realistically defined and supported.
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Matter is condensed energy. Matter derived from electromagnetic energy, supplied with the electrically powered BCEC systems (biologically closed electric circuits) inherits prerequisites to become biological matter. This is possible because mechanisms of BCEC systems contain the capacity to initiate structuring and functioning of matter. The principle of BCEC systems, their actual and potential importance for structure and function in biology and medicine, has been presented only in the form of a survey. Only few examples of the impact of the BCEC systems have been described. For detailed information, the reader is advised to take part of the original background articles by means of the reference list, which extends beyond the selected descriptions. Thereby it is hoped that the reader may get an understanding of the central biological role of the BCEC systems. They represent in this partial theory of the biological evolution a key mechanism which may provide the important primary steps that are necessary for the transfer of non-biological into biological matter. Second, also other factors are evidently contributing to biological differentiation, including for instance the principle of differential selection of species. Due to their basic role, the BCEC systems can nevertheless be recognized to be involved in the majority of structural and functional expressions in biology. This rests on the fact that our physical world once developed from energy and specifically its representation of electric energy. It has also been emphasised that electric energy is equivalent to the remarkable Oriental concept of Qi ("life energy"). Differences are predominantly a matter of semantics.
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The vast majority of cardioverter/defibrillator implantations is performed with non-thoracotomy lead systems. The temporal stability of defibrillation energy requirements is well established for epicardial defibrillation lead systems, but not for non-thoracotomy lead systems. The defibrillation energy requirements were reevaluated in 30 patients, 13 months after implantation of a cardioverter/defibrillator with a non-thoracotomy lead system. The study patients group consisted of 4 females and 26 males; mean age 60.1 +/- 10.5 years; mean left ventricular ejection fraction was 32.2 +/- 6.2%. Coronary artery disease was the underlying heart disease in 12 patients, dilated cardiomyopathy in 15 patients, and artificial valve replacement in 3 patients. There was no clinical progression in the underlying heart disease between defibrillator implantation and control measurements; left ventricular ejection fraction was unchanged (32.2 +/- 6.2 vs. 32.3 +/- 6.4%); no changes occurred regarding patients' clinical status. In 27/30 patients the defibrillation threshold at defibrillator implantation could be reconfirmed at control measurements. The mean defibrillation energy/requirements at implantation (14.4 +/- 4.8 Joules) were unchanged compared to control measurements (14.8 +/- 4.6 Joules). A temporal stability of defibrillation energy requirements could be established for the monophasic (n = 15; 18.0 +/- 4 vs. 18.1 +/- 3.4 Joules) as well as for the biphasic waveform (n = 15; 11.1 +/- 3.4 vs. 11.5 +/- 2.9 Joules). The results of intraoperative defibrillation thresholds measurements are predictive for chronic defibrillation energy requirements in patients with non-thoracotomy lead systems.
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A comparison between the life expectancy of patients with pacemakers and that of a control population of similar structure shows a parallel course, although originally, after a postoperative phase of 2 months, the mortality rate of the patients with pacemakers was higher. Today the results are considerably better. Implantation of pacemakers is one of the greatest cardiological advances in the last 10 years for the effective treatment and prevention of cardiac arrest in atrioventricular block. The significance of this type of therapy becomes understandable if the fact that the mortality of Adams-Stokes attacks used to be about 50% is taken into consideration. In France, about 5000 persons each year have Adams-Stokes attacks.
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