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Biomedical subjects

J Morgenstern

Publications and source records attributed to J Morgenstern.

At least 55 records · Page 3Linked to original sources
PubMed1986

[The cardiotocography instrument test].

This paper reports on a comparative test of eight cardiotocographic units which compute fetal heart rate on the basis of an ultrasonic signal. In order to ensure comparable test conditions for each unit, consisting of the monitor and the signal recorder, a simple measuring system was built. From outside the system, via a controlled electromagnet, a diaphragm in a water tank was put into defined motion. With individual recorders and by exploiting the Doppler effect it was possible to register and process each movement of the diaphragm. The frequencies and amplitudes of the artificially generated signals had been matched to the in vivo signals. The individual test graphs are compared, as a standard comparison, to the graphs obtained when the generation signal is fed to the direct ECG input of a cardiotocograph. In view of their high clinical information value, attention was focused in particular on the number of oscillations per minute and the oscillation amplitude. In this connection the electronic distortion of these two factors is as disregardable as portions of them which are incompletely or not at all recorded. Applying stringent criteria, the test shows that none of the units tested satisfies the desires of the obstetrician wanting to determine the fetal heart rate on a beat-to-beat basis.

Echocardiography↗
PubMed1980

[Critical analysis of the early perinatal morbidity at the department of obstet. gynecol. in Düsseldorf (1975-1977) (author's transl)].

A retrospective investigation of 219 deliveries (of 2870 deliveries between 1975-1977) with Apgar-scores less than or equal to 6 at 1 minute or UA-pH-values less than or equal to 7,15 is presented. Therefore the case histories of 75 spontaneous deliveries, 69 breech or forceps deliveries, and 75 cesarean sections were reviewed. Analysis of our data shows that in 32% of the spontaneous deliveries, in 61% of the breech or forceps deliveries, and in 29% of the cesarean sections the low Apgar- and UA-pH-values seemed to be avoidable. However, the comparison of 1973-1974 and and 1975-1977 gives evidence that the percentage of Apgar-scores less than or equal to 6 at 1 minute or UA-pH-values less than or equal to 7,15 decreased from from 13% to 8%. Also the incidence of severe acidosis of the newborn (UA-pH less than 7,10) was reduced from 2,3% to 0.8%. Further prevention of early perinatal morbidity and improvement of fetal outcome seems to us possible by: 1. the reduction of premature deliveries, 2. a greater application of the intermittent intrapartal tocolysis to avoid mid forcipes, 3. an intensive training for the objective interpretation of cardiotocography.

Acidosis↗
PubMed1979

[Serum kreatinkinase MB during fenoterol tocolysis (author's transl)].

In the investigation of possible myocardial damage, the assay of the heart specific isoenzyme kreatinkinase MB has established itself as a highly sensitive proof of a heart necrosis. In patients who underwent stationary treatment for premature contractions, the CK-activity was measured in the initial phase of tocolysis and additionally right before the therapy was ended. There was no laboratory indication of any heart damage due to tocolytic treatment.

Creatine Kinase↗
PubMed1979

[Cardiovascular changes of the foetal circulation during deceleration in acute foetal hypoxia (author's transl)].

Acute foetal hypoxia trials were conducted in 11 foetuses of sheep. The following parameters were determined continuously besides heart rate, art. pO2, arterial and venous blood pressure: cardiac output, stroke volume and system resistance. Acute foetal hypoxia was produced in two ways: 1) Compression of the maternal vena cava The arterial blood pressure in the foetus is increased. This is reflected mainly by the systolic blood pressure. This increase is provoked by the increase in stroke volume (up to 100%). This increase in stroke volume is so great that the cardiac output is increased despite the onset of deceleration. The system resistance remains unchanged. 2) Maternal hypoxia In contrast to foetal hypoxia as described above, the increase of stroke volume is not so pronounced at the onset of deceleration, and the system resistance is increased. After termination of maternal hypoxia there is an abrupt change of system resistance back to the original value. Both types of foetal hypoxia will subsequently not differ significantly from each other.

Acute Disease↗
PubMed1978

Log normal distribution of ovarian and placental steroid values in early human pregnancy.

Concentrations of estradiol, progesterone, 17OH-progesterone were measured by radioimmunoassay in individual serum samples obtained from a group of 304 women with normal gestations between the 4th and 17th week of pregnancy. Values obtained underwent statistical analysis in order to determine the arithmetic mean and the 95% normal range (+/- two standard deviations). It was noted hereby that the spread of values above the mean was greater than that below the mean, and that very often the mean minus two standard deviations was either close to zero or negative. Therefore, the data for each hormone were analyzed for normality of the distributions by the chi-square test. For each hormone the chi-square test was significantly different (p less than 0.001) from the normal distribution (Gaussian). Subsequently, linear transformation by rankit analysis revealed the log-normal distribution of our data. Furthermore, rankit analysis was used as a graphical method to delineate a useful clinical range, which includes the mean and meaningful 95% confidence limits for estradiol, progesterone, and 17OH-progesterone in early normal pregnancies.

Estradiol↗
PubMed1978

An eight channel telemetry system for the transmission of biomedical signals.

An eight channel telemetry system is presented which has low dimensions, low weight and is easy to use. The transmission is in the 430 MHz band on the basis of pulse-width modulation in a time-multiplex mode. A standard 9 volt battery offers a minimum of 15 hours operation with an accuracy of 1%. The upper limit frequency is currently at about 100 Hz. A 9th channel serves to monitor the function of the system.

Electrocardiography↗