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Biomedical subjects

D A Hall

Publications and source records attributed to D A Hall.

At least 145 records · Page 8Linked to original sources
PubMed1976

Occupational differences between conventional and saturation divers.

Diving experiences of 53 Divers First Class attending the U.S. Navy Saturation Diver Training Program were compared to 155 Divers First Class performing routine operational dives. The two groups were matched for years of diving experience, total number of dives, and total number of SCUBA dives. The Diving Experience Questionnaire (DEQ), which consisted of 43 items dealing with specific diving conditions and activites, was used to document the diving backgrounds of the two groups. Five of the 43 items were found to significantly and uniquely differentiate between the two groups. Those attending the Saturation Diving Program a) made more dives between 46-61 m (151-200 ft), b) had more experience with semiclosed-circuit SCUBA, c) attended more deep-diving training courses, d) made fewer dives in water warmer than 70 degrees F, and e) had fewer specialized qualifications outside deep diving. The multiple regression analysis which differentiated between the two groups resulted in an R of 0.48. These five items indicate that volunteering for saturation diving is consistent or congruent with past deep-diving experience, while remaining in conventional diving is congruent with previous shallow-water experience. These results indicate that the DEQ may be a highly useful method of differentiating between experienced divers.

Diving↗
PubMed1976

Associations between psychological factors and pulmonary toxicity during intermittent oxygen breathing at 2 ATA.

Associations between the psychological and pulmonary effects of breathing intermittent oxygen at 2 ATA were examined among four experienced divers. A fifth diver, who served as a control, breathed only normoxic nitrogen. Psychological tests included digit span, short-term memory for easy and difficult word associations, simple and complex psychomotor performance, and reported moods. The criterion of oxygen toxicity was the total hours of intermittent oxygen exposure tolerated before developing a 10% reduction in vital capacity. Short-term memory for difficult word associations and self-reported moods of Activity, Depression, Fatigue, and Happiness were found to be significantly correlated with this criterion of oxygen toxicity. Part of the impairment found on these measures, however, was probably related to the absence of adequate sleep and rest as evidenced by the worsened performance of the control diver over the 15-h testing period. The results replicated the findings of earlier research on the psychological effects of continuous oxygen breathing under hyperbaric conditions and at 1 ATA, and may indicate that oxygen intesifies the effects of other stressors such as fatigue. In addition, the results showed that reported moods may be important indicators of impending pulmonary toxicity during intermittent oxygen exposure.

Activities of Daily Living↗
PubMed1976

Gas phase separation during decompression in man: ultrasound monitoring.

During two dive series, one to 132 fsw and one to 210 fsw, Doppler ultrasonic bubble detectors were used to monitor venous gas bubbles in divers during decompression and for 30 min thereafter. Various decompression schedules were used. Bubble scores were evaluated by independent listerners to tape recordings in a blind manner. A significant increase in bubble scores throughout the stages of decompression and postdecompression was demonstrated as well as a statistically significant relationship between bubble score and decompression sickness. A reduction in mean bubble score was found in divers who made an additional deep decompression stop that was unrelated to the extension of the decompression time. The implications of these findings are discussed.

Adult↗
PubMed1975

Application of a programmable pocket calculator to a single compartment mathematical model of solute kinetics.

A single compartment mathematical model has been applied to kinetics of small solutes (urea and creatinine) in dialysis therapy. The model can be described by two equations requiring iterative solution of calculated values, given several measurable variables. The equations have been programmed onto a Hewlett-Packard 65 pocket calculator and recorded on 3 X 1/2" magnetic strips, facilitating clinical application to dialysis therapy.

Computers↗
PubMed1975

Quantitative evaluation of hemodialysis therapy using a simple mathematical model and a programmable pocket calculator.

1. A single pool mathematical model has been clinically tested and found to give values similar to those previously reported for volumes of distribution of creatinine and urea. 2. Calculated generation rates for creatinine and urea approximated values obtained by independent measurement of removal rate. 3. Preliminary observations suggest that the model may be empirically useful in predicting interdialytic serum creatinine urea concentrations. 4. The potential clinical usefulness of the mathematical model has been enhanced by development of a solution suitable for a programmable pocket calculator.

Adult↗
PubMed1975

Psychological characteristics of deep submergence vehicle personnel.

The personality and developmental characteristics of U.S. Navy Deep Submergence Vehicle (DSV) personnel, including operators and crews, were documented and compared to the characteristics of U.S. Navy divers. The results show that DSV operators (DSV Oprs) had a significantly less asocial developmental pattern than divers, while developmental experiences of DSV crews (DSV Crs) were similar to those of divers. Personality measures (EPPS) indicate that both DSV Oprs and DSV Crs are presently more sociable as adults than divers and would probably be more effective in situations involving small group interaction. The modifications which have occurred in the behavior of DSV Crs may be related to experience in the highly interpersonal DSV situation. The findings also show that DSV Oprs prefer to take fewer risks than divers, while the DSV Crs are more like divers in risk-taking behavior. The implications of this research to DSV mission effectiveness are discussed.

Adult↗