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Biomedical subjects

M Lampadius

Publications and source records attributed to M Lampadius.

14 recordsLinked to original sources
PubMed1978

[Clinical experience with the cage electrode EMT 588 K. Threshold--current consumption--postoperative complications (author's transl)].

The Lagergren cage electrode Elema EMT 588 K was implanted in 26 male and 21 female patients for permanent cardiac stimulation. 29 of the 47 cage electrodes were fitted with a platinum and 18 with an Elgiloy head. Acute threshold in the platinum group was 0,52 +/- 0,15 volts (x +/- s), the equivalent electrode resistance being 565 +/- 135 ohms. The threshold mean value for the Elgiloy cage electrodes was shown to be 0,36 +/- 0,11 volts, while the resistance values measured respectively 410 +/- 44 and 418 +/- 23 ohms depending on the method of measurement. In the postoperative period (up to 16 months) the following complications were observed: 3 dislocations (6,38%) and one case of rise in threshold (2,12%). The total correction rate (8,5%) corresponds almost exactly to that recorded by the author in a personal series of 400 electrode implantations of various designs. The cage electrode offers no advantages in comparison to other small surface electrodes, however, the relatively higher current consumption caused by low total electrode resistance must be regarded as disadvantages. Experience with the cage electrode has shown that the transitional resistance depends not only on the surface, but also essentially on the material and shape of the electrode tip.

Alloys↗
PubMed1977

[Lithium-powered cardiac pacemakers. A survey of 3 years' clinical experience (author's transl)].

In addition to the lithium-iodine cell which has been in clinical use since 1972, the following lithium-based power sources for cardiac pacemakers are available: The lithium-silver chromate cell (SAFT), the lithium-thionylchloride-battery (G.T.E.), the lithium-cupric sulfide cell (DuPont) and the lithium-lead iodide cell (Mallory). These batteries differ not only in their energy providing chemical reaction and their components (liquid electrolyte or not), but also in their capacity and discharge characteristics. Out of 244 lithium-powered pacemakers implanted during the past 3 years, 5 pulse generators had to be removed due to electronic circuit failure, whereas battery failure has not been observed up till now. Sensing problems were registered in 8 cases probably due to the specific properties of the entrance filter and entrance resistance of the pacer. In some cases, however, they were caused by poor electrode position. One pacemaker model, powered with the WGL702 cell, frequently gave rise to skin necrosis, Newer models have more favourable dimensions and lower specific weight. The capacity of their batteries is sufficient for middle to long-term stimulation when using current saving electrodes. Because of the well-known advantages of the lithium-cells in comparison to conventional Mallory batteries, together with the favorable clinical results, only lithium-powered pacemakers have been implanted in our hospital since 1977.

Electrodes↗
PubMed1976

[Heart pacemaker with lithium batteries. 2 years' clinical experience].

102 lithium-powered cardiac pacemakers manufactured by Cardiac Pacemakers Inc. (CPI 301 UD, 101 UA and 501 UD) were implanted in 94 patients. During the observation time (25 months) the following complications were registered: 2 pulse generator failures, 4 failures of the demand-function, anodic muscle-twitching in 2 patients, 2 erosions of the pacemaker-pocket and 1 hematoma of the pocket. 5 pulse generators were exchanged without malfunction of the pacemaker. In 4 patients reinterventions on the electrode had, to be performed. 4 deaths occurred, none of them related to malfunction of the pacemaker. 2 lithium-powered pacemakers were explanted in other hospitals, for reasons not known to us and 1 patient left the German Federal Republic. 83 patients are under control with well working lithium-powered pacemakers.

Arrhythmias, Cardiac↗
PubMed1975

[Prolonging the life of an implanted pacemaker by reducing impulse duration (author's transl)].

The current drain of a pacemaker depends on the electrical charge delivered to the heart during stimulation, the energy being determined by amplitude and width of the stimulating pulse. On investigating how far pulse duration can be shortened without jeopardizing reliability of cardiac stimulation, how much the current drain can be reduced and how this might influence pacemaker life, it was found that pulse width could be reduced to 0.3 ms in over 80% of cases with an increase in pacemaker life, if powered by conventional mercury batteries, to about 60 months.

Electricity↗