Search PubMed⌕ Search

Biomedical subjects

Emiel A den Hartog

Publications and source records attributed to Emiel A den Hartog.

2 recordsLinked to original sources

Postmortem time estimation using body temperature and a finite-element computer model.

In the Netherlands most murder victims are found 2-24 h after the crime. During this period, body temperature decrease is the most reliable method to estimate the postmortem time (PMT). Recently, two murder cases were analysed in which currently available methods did not provide a sufficiently reliable estimate of the PMT. In both cases a study was performed to verify the statements of suspects. For this purpose a finite-element computer model was developed that simulates a human torso and its clothing. With this model, changes to the body and the environment can also be modelled; this was very relevant in one of the cases, as the body had been in the presence of a small fire. In both cases it was possible to falsify the statements of the suspects by improving the accuracy of the PMT estimate. The estimated PMT in both cases was within the range of Henssge's model. The standard deviation of the PMT estimate was 35 min in the first case and 45 min in the second case, compared to 168 min (2.8 h) in Henssge's model. In conclusion, the model as presented here can have additional value for improving the accuracy of the PMT estimate. In contrast to the simple model of Henssge, the current model allows for increased accuracy when more detailed information is available. Moreover, the sensitivity of the predicted PMT for uncertainty in the circumstances can be studied, which is crucial to the confidence of the judge in the results.

Autopsy↗

Influence of inspiratory resistance on performance during graded exercise tests on a cycle ergometer.

Due to more stringent requirements to protect personnel against hazardous gasses, the inspiratory resistance of the present generation of respiratory protective devices tends to increase. Therefore an important question is to what extent inspiratory resistance may increase without giving problems during physical work. In this study the effects of three levels (0.24; 1.4 and 8.3 kPa s l(-1)) of inspiratory resistance were tested on maximal voluntary performance. Nine male subjects performed a graded exercise test on a cycle ergometer with and without these three levels of inspiratory resistance. Oxygen consumption, heart rate, time to exhaustion and external work were measured. The results of these experiments showed that increasing inspiratory resistance led to a reduction of time to exhaustion (TTE) on a graded exercise test(GXT). Without inspiratory resistance the mean TTE was 11.9 min, the three levels of resistance gave the following mean TTE's: 10.7, 7.8 and 2.7 min. This study showed that TTE on a GXT can be predicted when physical fitness (VO2-max) of the subject and inspiratory resistance are known. The metabolic rate of the subjects was higher with inspiratory resistance, but no differences were found between the three selected inspiratory loads. Other breathing parameters as minute ventilation, tidal volume, expiration time and breathing frequency showed no or minor differences between the inspiratory resistances. The most important conclusion of these experiments is that the overall workload increases due to an increase in inspiratory resistance by wearing respiratory protective devices.

Adolescent↗