Search PubMed⌕ Search

Biomedical subjects

B H Harris

Publications and source records attributed to B H Harris.

67 records · Page 4Linked to original sources
PubMed1975

Aeromedical transportation for infants and children.

Transfer of a critically ill child to a pediatric center is indicated when patient needs have exceeded local expertise or facilities. It is illogical to impose on the referring hospital the added burden of transporting such a patient. The receiving hospital is better equipped to extend its specialized services by assuming responsibility for interim management and transfer of the patient. An aeromedical transport system capable of quick response was built around National Guard helicopters. In 21 cases, doctors, nurses, and equipment were flown to children in community hospitals, and urgent treatment was begun in half the time formerly possible. Only after the patients were stabilized were they returned safely under continuing appropriate management. The helicopter is a versatile and speedy tool to deliver expertise and equipment when and where needed. Timely arrival of specialty services can be expected to improve patient care and salvage.

Aircraft↗
PubMedDate not supplied

Effects of mechanical and thermal fatigue on dental drill performance.

Osseous integration of dental implants depends on the use of proper surgical technique during site preparation, including the prevention of thermal injury to the surrounding bone. Heat generation during drilling has been reported to positively correlate with the production of forces at the surgical site. In this study, peak torque and axial load levels were measured during a drilling procedure into a polymeric material simulating the human mandible. Axial rotary milling was performed using 5 different twist drill designs (3i Irrigated Tri-Spade, 3i Disposable, Nobel-Biocare, Straumann, and Lifecore) of 15 to 20 mm in length and 2 to 2.3 mm in diameter, at a free-running rotational speed of 1,500 rpm and continuous feed rate of 3.5 mm/second, to a total depth of 10.5 mm. Ten drills representing each of the 5 types (n = 50) were subjected to 30 individual drill "pecks" and heat-sterilized every 3 "pecks" to determine the effects of cyclic mechanical and thermal loading on drill performance. Normal stress (sigma) and shear stress (tau) were calculated from the kinetic data and drill geometries. A drill efficiency coefficient (mu) was also calculated as the ratio of torsional resistance to translational resistance. Overall, the hypotheses of drill performance dependency on drill type as well as mechanical and thermal accumulated loading were tested and confirmed (P < .05). The 5 drill types produced a range of normal stresses (2.54 to 5.00 MPa), shear stresses (9.69 to 29.71 MPa), and efficiency (1.16 to 3.16) during repeated testing. Scanning electron microscopic images revealed minor deformations in the cutting edges of the tri-spade drills following testing.

Analysis of Variance↗
PubMedDate not supplied

Equipment and planning for neonatal air transport.

When transfer of a newborn infant by helicopter becomes necessary, electrical and mechanical devices are used to overcome some inconvenient aspects of the aviation environment. The aircraft must have an effective cabin heater, satisfactory interior illumination, a system for noise attenuation and voice communication, an oxygen source, and a supply of usable electric current. Medical equipment should be lightweight, portable, and designed or adapted for out-of-hospital use and have redundant energy sources. The transport incubator is the most important medical item. Electrical monitors for pulse, cardiac rhythm, blood pressure, respiratory rate, and body temperature are essential, and a defibrillator, infusion pump, and several other items are highly desirable.

Aircraft↗