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Biomedical subjects

B L Ho

Publications and source records attributed to B L Ho.

11 recordsLinked to original sources
PubMed1996

Rupture of dissecting aneurysm in a China Airlines co-pilot.

A 46-year-old male co-pilot of China Airlines developed shortness of breath during landing on a flight from Tokyo to Taipei on May 17, 1994. He was found dead shortly after landing. He was well and had passed his semi-annual health examination with no history of cardiovascular disease or hereditary disease. A dissecting aneurysm of DeBakey type I and cardiac tamponade with 200 ml blood inside the pericardial cavity during autopsy was noted. The right and left coronary arteries showed atherosclerotic changes with the lumen narrowing down to 30% in the anterior descending branch. Focal myocardial infarction with a healing scar, atheroma and arteriosclerosis of the small arteries including the kidney were observed. Nonspecific changes of the chest X-Ray and EKG with hyperlipoproteinemia suggests that a more advanced technique is required to carefully examine the heart condition during regular physical checkups to prevent sudden illness that might contribute to mass disaster.

Accidents, Aviation↗
PubMed1993

Hazard potential of ejection with canopy fragmentation.

The hazard potential of ejection with canopy fragmentation was evaluated by horizontal sled tests. A series of 14 ejections of tandem seats with 1st or 95th percentile anthropometric dummies were performed at sled speeds of 0, 150, 350, and 600 knots. Canopy-mounted miniature detonating cords (MDC) were fired in nine and not fired in five ejections. Maximal impact loads on each dummy's neck, knees, and shoulders were measured, and noise levels inside and outside the helmet recorded. The acceleration waveform for each dummy was recorded and used to calculate a dynamic response index (DRI) to assess the risk of spinal injury. Impacts with canopy fragments during ejections resulted in minor visible damages to the dummies and their equipment regardless of MDC firing. It was noted that MDC firing significantly attenuated the mean neck load (231 +/- 63 kg, unfired, to 108 +/- 20 kg, fired, p < 0.05). Noise levels with MDC firing averaged 162 dB. The mean DRI of dummy Gz for the small dummies was significantly greater than for large dummies (20.8 +/- 0.44 and 18.05 +/- 0.98, respectively, p < 0.05). We conclude that superficial injuries to ejecting pilots and their equipment is not a hazard with the canopy fragmentation system; however, spinal injury may occur at rates of 5 to 50% depending on the size of the pilot.

Aircraft↗
PubMed1984

A study of maximal oxygen consumption in Chinese males.

Maximal oxygen intake has been proposed as a standard for cardiovascular fitness. Measurement of maximal heart rate, blood pressure, oxygen consumption, and exercise duration can assess the individuals' functional aerobic capacity or reserve resulting from cardiac disease. The purpose of the present study is to evaluate the physiologic response to maximal treadmill exercise. The Chinese Air Force protocol (CAF protocol - a constant speed of 5.6 kmph with a 5% increase in grade every 3 min) was used in 202 healthy men of 30 to 57 years of age. Their mean maximal heart rate and maximal oxygen consumption are 181 b.m-1 and 40.4 ml.kg-1.m-1, respectively. The study revealed that aging bears a prominent influence on maximal heart rate and maximal diastolic pressure but not on systolic pressure. There are two major influences on max .Vo2, namely, age and habitual physical activity level. Activity had a more significant effect than the age factor. Maximal oxygen consumption was lower in sedentary than in physically active persons and diminished with age. It had a high correlation with duration of exercise by this standardized protocol. Accordingly by regression equations, average normal values from healthy persons could be predicted from activity status and age, and values expected on testing could be estimated from the duration of the exercise.

Adult↗
PubMed1982

A study of treadmill exercise protocols for Chinese males.

Treadmill stress testing currently is used in screening for coronary artery disease. Maximal oxygen consumption is the best index of work capacity and maximal cardiovascular function. Clinically, there are many exercise protocols being utilized, including Bruce, Kattus, Balke, Naughton, and Chinese Air Force (CAF). The purpose of this study is to compare five of them and evaluate their reproducibility. Each of 24 volunteers performed one exercise test per week for 3 periods totalling 15 weeks. During each period, the five different protocols were performed in individually randomized order. Maximal and submaximal oxygen consumption and heart rate were determined. Statistical analysis revealed no difference in maximal oxygen consumption among the various protocols; however significant differences did exist in maximal treadmill time. Maximal exertional duration was not affected by the test periods. All of the five protocols were equally reproducible. The Chinese Air Force has adopted a treadmill protocol with a constant speed of 3.5 mph and a 5% increase in elevation every 3 min. The physiological parameters measured by this protocol include a maximal heart rate of 181 beats/min; maximal oxygen consumption of 48 ml/kg/min; and maximal exercise duration of 17 min. Bruce and Balke protocols were 13 and 24 min, respectively, in our study. The regression equation of oxygen consumption and duration was: Y (ml/kg/min) = 1.26X (min) + 26.3. The CAF protocol is a safe, reproducible, easily performed method with moderate exercise duration. We confirm its advantages and prefer to select this protocol to serve as a routine screening or clinical method for use in testing Chinese people.

Adult↗
PubMed1975

A case report of spontaneous pneumothorax during flight.

Although spontaneous pneumothorax can usually be considered lightly when it occurs at ground level, its occurrence in aviation may result in the abort of a mission, a serious accident, or a major disaster. A case of spontaneous pneumothorax during chamber altitude and aerial flight is presented. A better understanding of the etiologies, precipitating causes, complications, likelihood of recurrence, and treatment may lead to the prevention of accidents. Diagnostic technics, operative procedures, and evaluation studies are discussed from the point of view of continuing a flying career.

Adult↗