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Biomedical subjects

R N Scott

Publications and source records attributed to R N Scott.

At least 73 records · Page 4Linked to original sources
PubMed1980

Clinical evaluation of UNB 3-state myoelectric control for arm prostheses.

This report describes an attempt to conduct (in 1978 during a period of one week) an intensive, thorough, and objective evaluation of a prosthetic control system in such a manner that the evaluation avoids what are seen as shortcomings common among evaluation procedures described in the literature. The evaluation, in terms of benefits to patients, involved consideration on an interdisciplinary basis among an engineering team, prosthetics team, and therapy team. Nine below-elbow and two forequarter amputees participated. The device evaluated was the University of New Brunswick 3-state myoelectric control system, in the 12-volt version designed in 1975. This system is intended for use where there are not enough control sites to permit use of an Otto Bock or similar control system, and permits on/off control of a powered hand or other device in two directions from a single muscle. Observations on each patient by the 14-person evaluation team are summarized, and an Appendix presents questionnaires with summarized responses of the subjects and their families.

Adolescent↗
PubMed1979

A comparison of simultaneous measurements of systolic function in the baboon by electromagnetic flowmeter and high frame rate ECG-gated blood pool scintigraphy.

Left ventricular (LV) systolic timing and relative volume variations were simultaneously measured by electromagnetic flowmeter (EMF) and high frame rate ECG-gated blood pool scintigraphy in five baboons. No significant differences (p greater than 0.1, paired t test) were observed in the time (from R wave) to peak aortic flow (maximum LV ejection rate), time to cessation of aortic flow (end-systole) or in the duration of aortic flow (LV ejection time). A small (approximately 15 msec) but significant systematic difference (p less than 0.02) was noted in the time to onset of aortic flow. The shape of each scintigraphic time-activity curve during systole was compared to an equivalent curve synthesized from 10 EMF flow profiles obtained in the same baboon. Comparison of these paired curves over systolic ejection yielded an average correlation or r = 0.95 (range 0.90--0.99). The ratio of peak flow to stroke volume determined from these data did not differ significantly (p greater than 0.05). In the baboon, quantitative high temporal resolution ECG-gated scintigraphy appears to reflect closely the detailed timing and relative magnitude variation of LV volume during the entire period of systolic ejection. We conclude that the assumptions underlying the scintigraphic method are valid in the baboon during the ejection interval.

Animals↗
PubMed1979

Education and certification of biomedical engineers in Canada.

The education of biomedical engineers in Canada is discussed, with reference to the Canadian health care system and related industry. Information on specific educational programmes, with enrollment data, is presented. The paper concludes with brief comments on the certification of clinical engineers in Canada.

Biomedical Engineering↗
PubMed1976

Brochial stump closure techniques following pneumonectomy: A serial comparative study.

Three methods of closing bronchial stumps were evaluated in 90 dogs undergoing left pneumonectomy:interrupted 3-0 silk sutures, interrupted 3-0 nylon sutures, and stapling with an automatic device. The dogs were sacrificed at 24 hours, 3, 5, 7, 10, and 14 days after pneumonectomy. Brochial stump leakage pressures and histological studies were performed on all specimens. Differences in the exudative reaction between silk and staple closures were significant on day 5(238.19+/- 23.28 SD PMN's/HPF in silk closures, 34.95+/- 20.37 SD PMN's/HPF in staple closures) and therafter(P less than 0.001). The reaction to nylon was intermediate between silk and staple. Collagen levels were highest at all periods for staple closures. Staple leakage pressures were greater than silk or nylon(day 5: 145.3 mm Hg +/- 64.9 SD in staple closures, 40.2 mm Hg +/- 15.4 SD in silk closures). These results have clinical relevance to the selection of suture materials for stump closures.

Animals↗
PubMed1976

Practical considerations for the use of a pulmonary artery thermistor catheter.

The use of a pulmonary artery thermistor catheter for pressure measurement and thermodilution cardiac output determination was evaluated in 11 dogs. Pulmonary artery wedge pressure was a reliable index of left atrial pressure at end-expiratory pressures less than 10 cm. H2O. Fluctuations in pulmonary artery temperature occurred at a frequency equal to the respiratory rate and an amplitude of 0.010 to 0.086 degrees C. Changes in amplitude were associated with changes in ventilatory waveform, respiratory rate, and level of anesthesia. Intermittent and continuous positive-pressure ventilation generally dampened and reversed the pulmonary artery temperature pattern exhibited during spontaneous breathing. This suggested that when end expiration is used to time indicator injection, cardiac output will be underestimated during spontaneous breathing and overestimated during continuous or intermittent positive-pressure ventilation. When indicator was injected at the same point in the ventilatory cycle, successive values of cardiac output deviated from one another by 0.0 to 6.7 percent. Deviations as large as 14 percent resulted if sequential injections were out of phase by half a respiratory cycle. These deviations can be minimized by injecting indicator at the same point in the respiratory cycle, if it is not feasible to measure cardiac output during apnea. The clinical utility of a pulmonary artery thermistor catheter can be optimized through appreciation of its specific strengths and limitations.

Animals↗
PubMed1975

The role of inflammation in bronchial stump healing.

The roles of inflammatory response and closure technique in the development of bronchopleural fistula were evaluated. Canine bronchial stumps closed with 3-0 silk and studied 14 days later were characterized by a dense inflammatory infiltrate. Stumps closed with 3-0 chromic catgut suture showed a moderate inflammatory response with disintegration of suture material. However, stumps closed with the automatic stapling device (TA-30) showed the best healing and a minimal degree of inflammation. These findings correlated well with leakage pressures. The average leakage pressure for the silk closed stumps was 139.44 mm Hg plus or minus 78.9 SD. This was significantly lower (P less than 0.02) than the average leakage pressure for staple closed stumps (251.25 mm Hg plus or minus 82.9 SD). It is concluded that the minimal amount of inflammation following staple closure will be associated with improved bronchial stump healing and a lower incidence of bronchopleural fistula.

Animals↗