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Weldon School of Biomedical Engineering Faculty Publications

1986

Articles 1 - 6 of 6

Full-Text Articles in Biomedical Engineering and Bioengineering

A Predictive-Adaptive, Multipoint Feedback Controller For Local Heat Therapy Of Solid Tumors, Charles F. Babbs, V A. Vanguine, J T. Jones May 1986

A Predictive-Adaptive, Multipoint Feedback Controller For Local Heat Therapy Of Solid Tumors, Charles F. Babbs, V A. Vanguine, J T. Jones

Weldon School of Biomedical Engineering Faculty Publications

Uniform heating of tumor tissue to therapeutic temperatures without damaging surrounding normal tissue is required for optimal local heat therapy of cancer. This paper describes an algorithm for online computer control that will allow the therapist to minimize the standard deviation of measured intratumoral temperatures. The method is applicable to systems incorporating multiple surface and/or interstitial applicators delivering microwave, radiofrequency, or ultrasonic power and operating under the control of a small computer. The essential element is a novel predictive-adaptive control algorithm that infers relevant thermal parameters from the responses of multiple temperature sensors, as each of the power applicators is …

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Effect Of Deferoxamine On Late Deaths Following Cpr In Rats, Charles F. Babbs, Sushil D. Kompala, Karl E. Blaho Jan 1986

Effect Of Deferoxamine On Late Deaths Following Cpr In Rats, Charles F. Babbs, Sushil D. Kompala, Karl E. Blaho

Weldon School of Biomedical Engineering Faculty Publications

The iron chelating agent deferoxamine was studied in an animal model as post-resuscitation therapy to prevent late deaths and brain damage following total circulatory arrest and resuscitation. Cardio-respiratory arrest was induced by injection of cold, 1% KC1 into the left ventricles of ketamine anesthetized rats pretreated with succinylcholine chloride, and by discontinuation of positive pressure ventilation. CPR was begun after six minutes, and animals with return of spontaneous circulation were entered into the study. Within five minutes after return of spontaneous circulation, treated animals received deferoxamine (50 mg/kg, IV). At ten days, 16 of 25 (64%) of treated animals had …

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Potassium Efflux From Myocardial Cells Induced By Defibrillator Shock, M J. Niebauer, L A. Geddes, Charles F. Babbs Jan 1986

Potassium Efflux From Myocardial Cells Induced By Defibrillator Shock, M J. Niebauer, L A. Geddes, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

A transient, dose-dependent cardiac depression was produced by defibrillator shocks in an isolated, working canine heart preparation perfused with oxygenated arterial blood from a support dog. Accompanying this depression was an efflux of potassium (K+ ), forced out of the myocardial cells by the passage of defibrillating current. The transient increase in extracellular K + concentration was recorded graphically in the venous outflow. It was found that 5-msec rectangular wave shocks, from three to ten times defibrillatory current threshold, released doserelated pulses of K+ . We conclude that because extracellular K + is a myocardial depressant, at least part of …

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Abdominal Binding And Counterpulsation In Cardiopulmonary Resuscitation, Charles F. Babbs, William E. Blevins Jan 1986

Abdominal Binding And Counterpulsation In Cardiopulmonary Resuscitation, Charles F. Babbs, William E. Blevins

Weldon School of Biomedical Engineering Faculty Publications

The history and potential of abdominal pressure as an adjunct to standard cardiopulmonary resuscitation (CPR) is reviewed. Abdominal pressure during CPR may be either static or phasic. Static abdominal pressure redirects limited blood flow generated by chest compressions toward the heart and brain, and away from the abdominal organs and lower extremities, thus boosting coronary perfusion pressure. Phasic abdominal pressure applied whenever chest pressure is released, in counterpoint to the rhythm of chest compression—so called interposed abdominal compression (IAC)-CPR—generates blood flow by an independent abdominal pump mechanism that augments the systemic perfusion created by chest compressions. New imaging data are …

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The Effect Of Carbon Dioxide, Lidoflazine, And Deferoxamine Upon Long Term Survival Following Cardiorespiratory Arrest In Rats, Stephen F. Badylak, Charles F. Babbs Jan 1986

The Effect Of Carbon Dioxide, Lidoflazine, And Deferoxamine Upon Long Term Survival Following Cardiorespiratory Arrest In Rats, Stephen F. Badylak, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This study examined the effect of carbon dioxide, lidoflazine, and deferoxamine therapy upon the 10-day survival incidence and subsequent neurologic function of rats subjected to 7 min of cardiorespiratory arrest with resuscitation. Cardiac arrest (asystole) was induced at time zero by injection of cold, 1% KCl into the left ventricle of ketamine-anesthetized rats pretreated with succinylcholine. Positive pressure ventilation was discontinued at time zero. Cardiopulmonary resuscitation (CPR) was begun at 7 min, and animals with return of spontaneous circulation were entered into the study. Twenty treated rats were ventilated for 1 h with 7% carbon dioxide-93% oxygen and given lidoflazine …

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Relationship Between Pulse-Wave Velocity And Arterial Elasticity, F J. Callaghan, L A. Geddes, Charles F. Babbs, J D. Bourland Jan 1986

Relationship Between Pulse-Wave Velocity And Arterial Elasticity, F J. Callaghan, L A. Geddes, Charles F. Babbs, J D. Bourland

Weldon School of Biomedical Engineering Faculty Publications

Pulse wave velocity (PWV) was measured in situ in 11 isolated canine common carotid arteries. Seven arteries exhibited a linear PWV vs. pressure function at pressures ranging from 0 to 200 mmHg. Four arteries yielded a linear relationship between PWV and pressure between 1 and 100 mmHg; for these vessels the relationship was nonlinear at higher pressures. Seven arteries (five from the group which was linear up to 200 mmHg and two from the group which was linear up to 100 mmHg) were excised and pressure/volume measurements were made in vivo. Using pressure/volume data, the Moens-Korteweg equation was evaluated as …

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