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Biomedical subjects

D B Olsen

Publications and source records attributed to D B Olsen.

At least 127 records · Page 7Linked to original sources
PubMed1984

The artificial heart in human subjects.

In preparation for clinical implantation of the Utah J-7 pneumatic artificial heart as a permanent cardiac substitute, the device was implanted into five brain-dead human subjects. This report presents our results and details our two most successful trials. Three different surgical implant techniques were utilized in the five subjects. Because of the unique "no risk" situation of the subjects, the function of the artificial heart could be tested in a manner not advisable in patients, but necessary for clinical preparation. The implantable total artificial heart was able to maintain physiological hemodynamics in two subjects for 41 and 72 hours at which time the trials were electively terminated.

Blood Pressure↗
PubMed1983

Twin calves, total artificial heart, cardiac transplantation.

Numerous laboratories throughout the world are successful in sustaining life in calves, sheep, and goats implanted with total artificial hearts for 4-8 months. Very good reliability has been demonstrated with some of these devices, and all of the more successful devices are pneumatically driven. These pneumatic controllers are, for the most part, large and nonportable, and thus are criticized when considered for permanent tethering to a human recipient. The artificial hearts, however, have been developed to a stage where they could sustain the circulation for indeterminate periods of time, for 2-3 years. The pneumatic total artificial heart was used for a few weeks in calves, and then followed with cardiac transplantation. This format has been suggested for human application.

Animals↗
PubMed1983

Response of the human body to the first permanent implant of the Jarvik-7 Total Artificial Heart.

The success of the first permanent total artificial heart implant would have been more obvious had the patient been able to be transferred from the hospital to an outlying home care setting. Nevertheless, several major achievements were realized. First, we were able to demonstrate that the total artificial heart will fit within an adult male chest without causing obstruction to inflow or outflow channels. Second, we were able to demonstrate that the total artificial heart would sustain life on a long-term basis (at least up to 112 days) without any evidence of systemic or local infection and without any untoward systemic effects. Third, we were able to demonstrate that the patient was able to tolerate a total artificial heart without complaint of the noise or the bulk of the drive system to which he required permanent attachment and that the patient could be comfortable and totally free of pain. An additional finding, which could not be assessed in the animal experimentations, was the fact that the patient was able to maintain higher CNS activity on an undisturbed basis following the implant of the total artificial heart. It is for these reasons that the entire University of Utah Medical Center staff feel great indebtedness to the patient and his family for demonstrating to the world the feasibility and the necessity for pursuing this device as a new therapy for end-stage heart disease.

Adolescent↗
PubMed1982

A comprehensive elementary model of the mammalian circulatory system.

Beginning with a set of simplifying assumptions and the statements for the hydrodynamic and thermodynamic processes involved, a comprehensive mathematical model for the mammalian circulatory system is developed and evaluated. Analytical relationships are derived and examined for the circulatory component pressures, flow rates, blood volumes, flow resistances, pumping power and pumping rate. The essential circulatory model parameters are identified and inspected for their influence upon circulatory behavior. A complete and consistent set of circulatory model parameters is given for the adult human male and the model response is examined. In general, agreement of the model predictions for man with experimental data is good.

Adult↗
PubMed1982

Intraoperative and immediate postoperative management of calves undergoing valve or total artificial heart implantation.

The intraoperative and immediate postoperative management data were recorded in a series of twelve artificial device implantation operations in calves. Nine of these were valved conduit experiments not requiring cardiopulmonary bypass, and three were total artificial heart implantations in which bypass was needed. The intraoperative and immediate postoperative management procedures of this laboratory are described including anesthesia, respiratory and drug therapy, and cardiopulmonary bypass management. This paper shows how these procedures may aid in reducing the recovery times of research animals.

Animals↗
PubMed1981

Are the Jarvik artificial ventricles limited by inflow resistance?

The pneumatic total artificial heart has been assumed to be inflow limited. Mock circulation studies on the Jarvik-5 and Jarvik-7 artificial ventricles seemed to support this assumption because a Starling's response comparable to the natural heart was not achieved. Unfortunately, mock circulation studies do not separate the effects of valvular regurgitation from inflow resistance. By using a simple filling tank, filling times were determined for the Jarvik ventricles that were a function of inflow resistance alone. Theoretical maximum cardiac outputs based on these inflow resistance-dependent filling times were then calculated. For filling pressures around 5 mmHg and under modest diastolic vacuum of 5 cm H2O, the Jarvik ventricles yield a theoretical cardiac output as good as the natural heart's. Thus, inflow resistance is not a limiting factor and valvular regurgitation is left as the most likely cause of a less than optimal Starling's response on mock circulation and in vivo.

Cardiac Output↗
PubMed1981

A seven-month survival of a calf with an artificial heart designed for human use.

A Jarvik-7 type of pneumatic artificial heart, which was specifically designed to fit the anatomy and hemodynamic requirements of human patients, was implanted in a calf in an experiment to test the hemodynamic performance of the artificial heart. The experiment lasted for 221 days, longer than any animal had ever lived without its natural heart, despite the fact that the calf increased its body weight to 171 kg. The calf showed typical signs of low cardiac output before its death, but the direct cause of death was intestinal bleeding. At autopsy, it was discovered that the low cardiac output was due to severe pannus around the left inflow valve, as diagnosed earlier by changes in the pneumatic pressure wave form.

Animals↗
PubMed1981

Determinants of pannus formation in long-surviving artificial heart calves, and its prevention.

In a group of 76 calves maintained with Jarvik-5 and Jarvik-7 artificial hearts, pannus formation in the atrial location was evaluated retrospectively using a grading system based on measurement of the pannus tissue. Pannus was present in 87% of the calves surviving one to 7 mos with an old-style inflow quick-connect design utilizing polyester felt surfaces. This design had a suboptimal hemodynamic flow path. Using a new design of quick-connect with an improved hemodynamic flow path and a Biomer blood-contacting surface, pannus occurred only in 17% of calves surviving one to 9 mos. Furthermore, the pannus formation with the new design was mild in the 2 cases where it occurred, whereas the pannus formation in animals with the old cuffs was frequently severe. One calf survived 9 mos with no pannus formation utilizing our new quick-connect system, and we conclude that pannus is no longer a problem in our experiments. We also reviewed the relation of pannus to anticoagulant regimens and found that Persantine, Coumadin, and aspirin were not effective in preventing pannus when the inflow cuff design was conducive to its development.

Animals↗