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Biomedical subjects

E K Hunter

Publications and source records attributed to E K Hunter.

4 recordsLinked to original sources
PubMed1986

An external automatic device to detect ventricular fibrillation.

An analysis of a micro-processor-based system to detect cardiac arrest rhythms was made in a series of 84 cardiac arrests in 78 patients. The ECG was sensed using 2 external ECG/defibrillator pads applied to the chest wall. In 5 arrests, the initial rhythm was continuous electrical pacing in addition to the cardiac arrest and these were not included in the analysis. Of the remaining 79 arrests there were 15 in which the initial rhythm was ventricular fibrillation and 14 were correctly detected by the system (sensitivity 93%). In the remaining 64 arrests the initial rhythm was not ventricular fibrillation and 62 were correctly identified (specificity 97%). A high specificity is required in any device employing automatic detection of ventricular fibrillation. Continuous electrocardiographic recordings of the cardiac arrests were analysed every 8 to 18 s: of 223 sections showing ventricular fibrillation, 165 were correctly determined by the system, i.e. sensitivity 74%, where the rhythm was not ventricular fibrillation, of the 5002 sections 4953 were correctly detected by the system, i.e. specificity 99%. The percentage accuracy of detection of ventricular fibrillation varied from 25-100% (mean 81%) and for detection of non-ventricular fibrillation from 57-100% (mean 99%) in every 8 to 18 s section of ECG tracing per cardiac arrest episode. Thus the automatic detection of cardiac arrest rhythms is feasible with a high degree of accuracy.

Adolescent↗
PubMed1986

Automatic detection of cardiac arrest rhythms prior to automatic external cardiac defibrillation.

The detection and correction of ventricular fibrillation at the earliest time after its onset is essential to ensure long-term survival. During successive cardiac arrests the rhythms occurring were sensed by using disposable pre-gelled ECG defibrillator pads placed in the anterior-anterior position. Simultaneously with the treatment, the arrest rhythms were analyzed continually every 8 to 18 seconds by a microprocessor system. This system sampled digitally the electrocardiogram, and the algorithm looked for absence of the isoelectric segment, irregular energy density spectrum, and irregular wave shape. The analysis was displayed visually as ventricular fibrillation (VF) or non-VF, and simultaneously the ECG and system's analysis were recorded on tape. Later, the system's interpretation of the rhythm was compared with the ECG record. There were 46 males and 32 females. Their ages ranged from 14 to 85 years, with a mean of 63 years. Twenty-nine patients had sustained an acute myocardial infarction. In the remaining 49 patients, there were a variety of causes for cardiac arrest, including heart failure, vasovagal syncope, cardiomyopathy, and postoperative cases. We report in detail the process and results.

Journal Article↗
PubMed1984

Midazolam for upper gastrointestinal endoscopy.

A water-soluble benzodiazepine, midazolam, was used in 400 patients undergoing upper gastrointestinal endoscopy, alone or in combination with pentazocine and compared with 68 patients given diazepam (Valium). In the last 200 patients the endoscopist used midazolam without the presence of an anaesthetist. The absence of injection pain was the most notable feature of midazolam. The degree of co-operation was similar in all groups but the operating conditions were significantly better when midazolam was combined with pentazocine. There was no significant difference in recovery times between the groups as assessed by the pegboard test. Midazolam is an acceptable alternative to diazepam for upper gastrointestinal endoscopy.

Adult↗