Ten experimental perfusions with autogenous oxygenation were performed in mongrel dogs to evaluate the efficacy of the procedure in maintaining normal hemodynamic conditions and adequate blood gases for 1 h. Blood was drained from the right and left atria and pumped to the pulmonary artery and aorta, respectively. Two closed circuits containing compliant chambers and roller pumps were utilized. Artificial ventilation with an Fio, of 50% were used in 5 animals and with an Fio, level of 30% in the other 5. EKG, cardiac output, aortic, pulmonary artery, and left atrium pressures were registered. Pulmonary tissue was biopsied after perfusion. The heart was electrically fibrillated after perfusion was established and defibrillated at the end of the bypass. The procedure was able to maintain blood gases and pulmonary, aortic, and left atrial pressures within normal ranges during the perfusion. The mobility of the heart and the access to all coronary arteries was excellent. Clinical central nervous system evaluation, EKG tracings, and pulmonary histological exams showed no adverse effects of perfusion. We conclude that the technique employed may present a suitable proceeding for extracorporeal circulation in closed heart surgeries, and its clinical application should be evaluated as a safe and economical alternative. Leirner, Rua Pernambuco, 15-Apt. 41, Sio Paulo, 0124-020 Brazil. 16. Helmsworth JA, Shabetai R, Cole WR, Neely JC, Albers JE, Gonzales LL. A method of cardiac bypass with autogenous oxygenation. Surgery 1959;45: 129-37. 17. Atkins CW. Early and late results following elective isolated myocardial revascularization during hipothermic fibrillatory arrest. Circulation 1985;72 (Suppl 3):375. 40:237-52. 425-9.
This paper describes the design of a ventricular assist device (VAD), its manufacturing, and testing. The VAD presented is pulsatile, with a free-floating membrane, smooth internal surfaces, and pericardial valves. It comprehends also a pneumatic driving unit capable of operating in the "full to empty," EKG synchronized or asynchronous modes. In vitro tests were performed to assess its mechanical durability, hydrodynamic performance, and hemolysis. To optimize cannulas and implant techniques, we performed in vivo tests in 22 sheep and 8 calves. In these tests, we also evaluated hemolysis and the device's capacity to normalize hemodynamic parameters during induced cardiac failure. The VAD worked for 4,000 h without failure in a mock circulatory loop. In full to empty mode, it displayed a rate-mediated "Starling-like" performance. Optimum output was achieved with a systole duration of 40% of the cycle. The in vitro hemolysis index (IH) was 6.7 +/- 2.1. Hemolysis in animal experiments was clinically nonsignificant. In calves with induced cardiac failure, the VAD was able to normalize hemodynamic parameters within 120 min.
The IMPT generated by acute 50 Hz application of FES is higher than the one generated by 15 Hz, but it is lower than MVC in controls and patients with heart failure.
Data on patients' profiles were made available through services provided by the MU--including the average index of 1.85 devices delivered to each patient and demand projections--which can be used in the planning of public policies. The MU made rehabilitation services more accessible, trained professionals, raised awareness on the correct delivery and use of assistive devices, and identified and organized people's demand in each region. Implications for Rehabilitation Delivering prostheses, orthoses and other mobility aids fulfills the rights of persons with disabilities to personal mobility with the greatest possible independence, as foreseen by the Convention on the Rights of Persons with Disabilities, increasing their participation in society on an equal basis with others. The direct impact of actively reaching out into the community to provide quality rehabilitation services and assistive devices increases the level of access of persons with disabilities to health services and equalizes opportunities. Outreach initiatives to deliver rehabilitation services in the community must include a capacity-building component. Building the capacities of local practitioners and health personnel will further empower both these professionals and persons with disabilities, diminishing attitudinal barriers. Reaching out into the community allows gathering data on the prevalence of health conditions, local need and demand for assistive devices and rehabilitation services, and informs decision-making.
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