Biomedical Engineering and Bioengineering Commons^™

Theoretical Advantages Of Abdominal Counterpulsation In Cpr As Demonstrated In A Simple Electrical Model Of The Circulation, Charles F. Babbs, Sandra H. Ralston, Leslie A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

Animal studies and preliminary clinical observations suggest that the addition of interposed abdominal compressions (IAC) to ventilation and chest compression of standard cardiopulmonary resuscitation (CPR) augments blood flow, blood pressures, and immediate survival. To investigate the physical basis for enhanced circulation during IAC-CPR, we developed an electrical model of the circulation. Heart and blood vessels were modeled as resistive-capacitive networks, pressures as voltages, blood flow as electric current, blood inertia as inductance, and the cardiac and venous valves as diodes. External pressurization of the heart and great vessels, as would occur in CPR, was simulated by application by half-sinusoidal voltage …

Efficacy And Safety Of The Reciprocal Pulse Defibrillator Current Waveform, M J. Niebauer, Charles F. Babbs, L A. Geddes, J D. Bourland

Weldon School of Biomedical Engineering Faculty Publications

The efficacy and safety of a new defibrillating current waveform, consisting of a low-tilt 5 ms trapezoidal pulse followed closely by a second identical pulse of opposite polarity, was tested m seven isolated, perfused, working canine hearts suspended in an isoresistive, isosmotic shock bath at 37 oC. The efficacy and safety of the reciprocal pulse was compared with a single 5 ms pulse, a single 10 ms pulse, and a dual (unidirectional) 5 ms pulse waveform. The mean threshold average current densities for the 5 ms single pulse, 10 ms single pulse, dual 5 ms pulse, and reciprocal pulse (absolute …

Fuel Ethanol From Raw Corn, Curtis Weller, M. P. Steinberg, E. D. Rodda

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crude amylase preparations were produced by growing Aspergillus awamori and A. niger on raw, ground, whole corn. These Koji preparations were used to hydrolyze the starch of raw, ground whole corn to sugars during simultaneous fermentation of the sugars to ethanol by distillers active dry yeast. Ethanol concentrations of the fermentation beers were determined with gas-chromatography. These fermentations yielded an average of 89.6% theoretical ethanol compared to control, conventional, fermentations that had an average of 89.9%. Carbon dioxide evolutions were determined with use of Alwood valves. The initial fermentation rate was greater for the conventional fermentation than the Koji fermentation. …

Tillage, Residue And Erosion On Moderately Sloping Soils, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Thomas Peterson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Tillage treatments leaving 20% or more of the soil surface covered with residue reduced soil erosion by at least 50% of that which occurred from a moldboard plow system. No-till had the least erosion and tended to have the lowest cumulative runoff. These results were based on rainfall simulation tests on six tillage treatments used on both 5 and 10% slopes in continuous corn production.

Computer Simulation Of The Human Hypophysial-Ovarian System, Robert Charles Blencowe

Theses

In order to more adequately simulate the human pituitary-ovarian cycle further refinements were made to the original Bogumil and Feng computer models. This involved the inclusion of equations which mathematically describe the peripheral conversion of prehormones and a subroutine showing the effect of plasma proteins, TeBG, CBG, and albumin on the total concentration of estradiol, progesterone, testosterone, androstenedione, dehydroepiandrosterone and estrone.

Once the models were functioning properly, values for the normal state and for the disease condition, Polycystic Ovary Syndrome (PCO), were obtained. In most cases there exists good agreement between the results reported in the literature and those generated …

Computer Simulation Of The Respiratory System, Bruce Diner

Theses

The respiratory system was simulated utilizing a series of three models, each more complex than the previous. The first model simulated the respiratory system as a two compartment model driven by carbon dioxide concentration. The second model, also a two compartment model, simulated periodic breathing while the third model is a three compartment model and simulates acid-base balance disturbances.

In this study, the effects of hyperthyroidism and respiratory center depression on respiration premeasured utilizing the models to obtain data and then compare the results to known physiologic data.

Bioassays- Procedures And Results, A. F. Maciorowski, L. W. Little, L. F. Raynor, Ronald C. Sims, J. L. Sims

Biological Engineering Faculty Publications

Bioassay procedures to describe, evaluate, and predict the potential hazard of toxic materials to organisms and ecosystems, and the health-related aspects of polluted waters continue to receive widespread attention. Symposium proceedings and books pertinent to toxic substances management and test procedures have appeared, as have several literature reviews pertinent to specific pollutants. The proceedings of the fifth annual ASTM symposium on aquatic toxicology presented a collection of papers directed to research needs in aquatic toxicology and hazard assessment, new concepts in aquatic toxicology, biological availability and sediment toxicity, and hazard assessment and water quality criteria.¹ A state-of-the-art overview pertinent …

Effects Of Tillage On Soil Erosion In A Wheat-Fallow Rotation, Elbert C. Dickey, C. R. Fenster, J. M. Laflen, R. H. Mickelson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Erosion from alternative tillage systems in winter wheat-fallow rotations was measured using a rainfall simulator. The Nebraska study, conducted at the High Plains Agricultural Laboratory, showed that during the fallow period between harvest and tillage, soil erosion was not affected by the tillage systems studied. However, erosion following tillage was different for the systems evaluated and moldboard plowing with the slope had the largest amount. The no-till system reduced erosion by about 95% during this period. Although contour plowing was effective in reducing erosion when compared to plowing with the slope, no differences were measured between with the slope and …

Yield Comparisons Between Continuous No-Till And Tillage Rotations, Elbert C. Dickey, Thomas Peterson, J. R. Gilley, L. N. Mielke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Continuous use of no-till planting systems may result in reduced yields, especially on finer textured soils that tend to be poorly drained. Soil compaction and poor soil aeration have been identified as possible factors contributing to the lower yields. Research conducted to evaluate tillage rotations on these soils shows that periodic use of the moldboard plow can result in statistically higher yields as compared to continuous no till. However, use of chisel plow and disk tillage systems following three years of continuous no-till did not result in yield increases. A relationship between cone penetrometer index and yield indicates a trend …

Effects Of Myocardial Infarction On Catheter Defibrillation Threshold, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Because the automatic implantable defibrillator may be used in patients having ischemic heart disease, it is important to know whether myocardial ischemia changes the threshold for ventricular defibrillation under experimental conditions simulating automatic internal defibrillation. We determined changes in ventricular defibrillation threshold following coronary occlusion, using an electrode catheter designed for use with an automatic implantable defibrillator. Acute myocardial ischemia was produced without thoracotomy in 10 dogs (experimental group) by embolization with a plastic bead injected via a catheter into the left coronary artery. A control group of 4 dogs had only saline injected into the artery. Defibrillation threshold was …

Simple Methods For Determining The Accuracy Of Tumor Blood Flow Measurements Using Radioactive Microspheres In Rats, Rosanna C. Chan, Charles F. Babbs, Richard J. Vetter

Weldon School of Biomedical Engineering Faculty Publications

Two simple methods are presented that allow positive identification of the accuracy and precision of the microsphere technique and a quick verification of sphere entrapment in tumor vessels. A known flow of Ringer's solution from a motor-driven syringe is perfused through the rat's isolated systemic circulation from left ventricle to right atrium and collected in a funnel. Using this preparation, total blood flow in rats measured with radioactive microspheres injected into the left ventricle was 97% of actual flow. The coefficient of variation (standard deviation/mean) of the microsphere measurements was 0.22. In the same preparation, non-entrapment of microspheres in subcutaneous …

Improved Oxygen Delivery During Cardiopulmonary Resuscitation With Interposed Abdominal Compressions, William D. Voorhees, Mark J. Niebauer, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The ability of a new modification of cardiopulmonary resuscitation (CPR) to deliver oxygen to tissues was evaluated. The method utilizes standard CPR techniques with the addition of manual abdominal compressions (100 mm Hg) interposed between chest compressions, and is termed interposed abdominal compression-CPR (IAC-CPR). Oxygen delivery was measured by a spirometer in a closed circuit designed to permit positive-pressure ventilation synchronized with mechanical chest compression. Ventricular fibrillation was induced electrically in 10 anesthetized dogs. In each dog, trials of IAC-CPR and standard CPR were alternated every five minutes during a 30-minute period. Arterial and central venous blood pressures, oxygen consumption, …

Relationship Of Blood Pressure And Flow During Cpr To Chest Compression Amplitude: Evidence For An Effective Compression Threshold, Charles F. Babbs, W D. Voorhees, K R. Fitzgerald, H R. Holmes, L A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

This study was conducted to investigate the importance of the depth of chest compression in producing effective cardiopulmonary resuscitation (CPR) in animals, as indicated by cardiac output and mean arterial blood pressure. Cardiac output was measured by a modified indicator dilution technique in 8 anesthetized dogs, 6 to 12 kg body weight, during repeated 2-minute episodes of electrically induced ventricular fibrillation and CPR provided by a mechanical chest compressor and ventilator (Thumper^®). Chest compression exceeding a threshold value (x₀) between 1.5 and 3.0 cm was required in each animal to produce measurable cardiac output. In particular, …

Taxonomy Of Corynebacterium Plant Pathogens, Including A New Pathogen Of Wheat, Based On Polyacrylamide Gel Electrophoresis Of Cellular Proteins, Randall R. Carlson, Anne K. Vidaver

Biological Process Development Facility: Staff Publications

The known extant plant pathogenic Corynebacterium species were analyzed by polyacrylamide gel electrophoresis of their cellular proteins. The patterns of the protein bands of 13 species and a new corynebacterial wheat pathogen showed seven distinct groups. Five of these groups consisted of only one species each, one group contained four species, and the last group contained the new wheat pathogen and the remaining four species. The pathogens that could not be distinguished by the polyacrylamide gel analysis differed in phenotypic characteristics, including pathogenic specificity. Thus, for these bacteria we propose recognition of the following taxa: C. fascians (Tilford) Dowson, …

Investigation Of Blood Pressure Measurement Using A Hydraulic Occlusive Cuff, Kusha R. Bhattarai

Dissertations and Theses

This thesis presents an improved oscillotonometric system for the measurement of human blood pressure. The study included:

1. The design of a hydraulic occlusive cuff,

2. The investigation of the wave forms taken from the blood pressure measurements, and

3. The design of a mechanism for the simulation of human blood pressure pulse.

In this study, an experimental system consisting of a rigid shell occlusive cuff, a constant volume displacement pump, a transducer, and a chart recorder was designed and used for data collection.

Bioassays- Procedures And Results, A. F. Maciorowski, L. W. Little, Ronald C. Sims, J. L. Sims

Biological Engineering Faculty Publications

Bioassay procedures to describe, evaluate, and predict potential hazard of toxic materials to organisms, ecosystems, and health-related aspects of polluted waters continue to receive widespread attention. However, synthesizing these diverse theoretical, methodological, and procedural entities into an integrated multidisciplinary approach to evaluate environ mental hazards of toxic substances remains difficult. Symposia proceedings pertinent to the toxic substances management in ecosystems have appeared¹ and provide an overview of major problems and emerging solutions, including chapters on new bioassay protocols development, and multiple exposure toxicity paradigms. Conclusions and recommendations resulting from a toxicity testing workshop² discussed current state-of-the-art, identified needed …

Field Evaluation Of Calibration Accuracy For Pesticide Application Equipment, A. R. Rider, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A 1979 field survey was conducted in Nebraska and western Iowa of 152 private and commercial pesticide applicators. The survey showed that only one out of every four cooperators were applying pesticides within 5 percent of their estimated application rate. Incorrect calibration accounted for the greatest amount of application errors and ranged from nearly 60 percent under application to more than 90 percent over application. Uniformity of the application was also in error. The coefficient of variation among nozzles for liquid applicators averaged 21.9 percent whereas granular applicators averaged 4. 7 percent among boxes. The survey also showed that the …

Bacterial Mosaic: A New Corynebacterial Disease Of Wheat, Randall R. Carlson, Anne K. Vidaver

Biological Process Development Facility: Staff Publications

Bacterial mosaic is a foliar disease of wheat; characteristic symptoms are small yellow lesions, more or less uniformly distributed over the leaf. It was discovered in Nebraska in the spring of 1976. By 1979, the pathogen was distributed over an 800-km range and had been isolated from 16 cultivars of winter wheat. The pathogen is Corynebacterium michiganense subsp. tessellarius, a Gram-positive coryneform. Wheat was the only host that showed symptoms after inoculation. The pathogen reached high population levels (> 10⁶ colony-forming units per gram of fresh weight) without apparent symptoms in tomato and in six of nine gramineous …

Tillage Factors Affecting Corn Seed Spacing, Paul J. Jasa, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

An on-farm survey was conducted in Nebraska to determine factors affecting corn seed spacing uniformity. Statistical analysis indicated that relative surface roughness, amount of residue present, amount of preplant tillage, and tillage system were important factors affecting uniformity. Subsequently, replicated tillage plots at eight locations were used to evaluate seed spacing uniformity with different planters and tillage systems. Seed spacing coefficient of variation and a planter index developed showed conservation tillage does not significantly reduce seed spacing uniformity.

Equipment For Local Hyperthermia Therapy Of Cancer, Charles F. Babbs, James R. Oleson, John A. Pearce

Weldon School of Biomedical Engineering Faculty Publications

Rapid improvements in hyperthermia apparatus are being achieved by industrial and university-based research groups that have already led to the marketing of a variety of commercial systems for heat therapy of malignancy. These tissue heating systems employ microwaves, capacitively or inductively coupled radiofrequency current, or high intensity ultrasound to produce controlled local heating of tumor tissues. No single system is superior to others in all applications; each has its limitations.

Characterization Of The Oscillometric Method For Measuring Indirect Blood Pressure, L A. Geddes, M Voelz, C Combs, D Reiner, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

In this study, human subjects and dogs were used to determine the ability of the oscillometric method to indicate systolic and diastolic pressure. In the human studies, the auscultatory method was used as the reference. In the animal studies, directly recorded blood pressure was used as the reference. The ability of the sudden increase in cuff pressure oscillations during cuff deflation to indicate systolic pressure was examined and found to overestimate systolic pressure slightly in man, but more in animals. Systolic pressure was encountered when the cuff pressure oscillations were about one half of their maximum amplitude. However, in both …

Biology Of Local Heat Therapy For Cancer, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Successful cancer therapy must selectively destroy tumor tissue while sparing the host's normal tissues. Local heat treatment can have such a selective effect because abnormalities in tumor blood vessels supply less oxygen to heat-stressed tumor cells and are less efficient in cooling tumor tissue by blood perfusion.

Hydralazine-Enhanced Selective Heating Of Transmissible Venereal Tumor Implants In Dogs, William D. Voorhees Iii, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This study was designed to test the hypothesis that vasodilator drugs can enhance selective heating of solid tumors by producing a favorable redistribution of blood flow between tumor and normal tissues. Subcutaneous transmissible venereal tumor implants were heated by inductive diathermy using Helmholtz coils in 8 dogs. The temperature rise in tumor and adjacent muscle was measured before and after giving hydralazine (0.5 mg/kg i.v.). Blood flow to the tumors and underlying muscle was measured with radioactive tracer microspheres. Before hydralazine treatment mean muscle blood flow was about one-third tumor blood flow (0.11  0.02 vs. 0.28  0.09 ml/min/g), …

Theoretical Feasibility Of Vasodilator-Enhanced Local Tumor Heating, Charles F. Babbs, David P. Dewitt, William D. Voorhees, Janet S. Mccaw, Rosanna C. Chan

Weldon School of Biomedical Engineering Faculty Publications

Normal arterioles, in contrast to the abnormal microvasculature of many solid tumors, provide a target for selective drug action that can enhance local heat treatment of the tumors. Measurements of tissue blood flow with radioactive microspheres and estimates of changes in blood flow with thermal clearance methods revealed that vasodilator drugs either decreased or did not alter blood flow in hamster melanoma, rat hepatoma, and canine transmissible venereal tumor, while increasing perfusion in adjacent normal tissues 2 to 4-fold. Solutions of the bio-heat transfer equation, which take into account such selective effects of vasodilators on blood flow in normal tissues, …

Cardiopulmonary Resuscitation With Interposed Abdominal Compression In Dogs, Sandra H. Ralston, Charles F. Babbs, Mark J. Niebauer

Weldon School of Biomedical Engineering Faculty Publications

This study was conducted to evaluate the hemodynamic effectiveness of a new modification of cardiopulmonary resuscitation (CPR), termed interposed abdominal compression- CPR (IAC-CPR). IAC-CPR utilizes all the steps of standard CPR with the addition of abdominal compressions interposed during the release phase of chest compression. Ventricular fibrillation was induced electrically in 10 anesthetized dogs, and either IAC-CPR or standard CPR was initiated while arterial and venous blood pressures and cardiac output were monitored. The two CPR methods were alternated every three minutes over a period of thirty minutes. The addition of interposed abdominal compressions to standard CPR improved arterial pressures …

Carminomycin Analogue, Hassan S. El Khadem, David L. Swartz

Michigan Tech Patents

A novel anthracycline glycoside 2-deoxy-L-fucopyranosyl carminomycinone which is effective for inhibiting the growth of tumors such as leukemia L1210.

Vegetative Filter Treatment Of Livestock Feedlot Runoff, Elbert C. Dickey, D. H. Vanderholm

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Four vegetative filters were installed on feedlots in central and northern Illinois. Two configurations were used: channelized Dow and overland Dow. After settling for partial solids removal, runoff was applied directly to the filters and allowed to Dow from the inlet to the outlet section. Results from measurement analyses and sampling of influent, effluent, and surface Dow at intermediate points were reported.

Most runoff events were infiltrated completely, resulting in no filter discharge. Runoff from larger events was partially discharged. Filters removed as much as 95% of nutrients and oxygen-demanding materials from the applied runoff on a weight basis, and …

Mound Sewage Waste Treatment Systems, Elbert C. Dickey, Phillip W. Harlan, Cheryl Kisling-Crouch

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Several areas in Nebraska are not appropriate for onsite home sewage treatment using conventional septic tank absorption field systems. Site factors that limit the use of conventional absorption fields include slowly permeable soils, shallow or gravelly soils and high water tables. The septic tank-mound system, which consists of a septic tank for primary sewage treatment and a constructed mound for final waste treatment was developed to overcome these site limitations (Figure 1).

Although mound systems differ only slightly in principle from conventional sewage systems, they allow the user to select suitable materials to build an absorption field that relies …

Crop Residue Management For Water Erosion Control, Elbert C. Dickey, P. W. Harlan, Don Vokal

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop residues are playing an increasingly important role in today's agricultural management systems. In the past, residues were normally chopped or disked and plowed under in the process of seedbed preparation. Distributed throughout the deep-tillage layer, the residues decomposed rapidly and recycled organic matter back into the soil. Use of the traditional moldboard plow tillage system also provided a loose, residue-free seed bed. Unfortunately, moldboard plow tillage systems have high soil moisture losses which can reduce yields in low rainfall areas or during dry years.

Incorporating previous crop residues also leaves the soil surface exposed to agricultural runoff which causes …

Tillage Systems For Row Crop Production, Elbert C. Dickey, Allen Rider, Phillip W. Harlan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Selecting a tillage system that is best suited to a particular farming situation is an important management decision. In the past, a crop producer's primary concerns were field capacity and the costs of owning and operating equipment. However, with rapidly increasing energy costs, alternative tillage systems are being carefully evaluated and selected by more producers.

Previously, the most common tillage system included a moldboard plow to turn residue under either in the fall or spring. Following plowing, spring tillage normally included one or more shallow diskings to kill weeds, incorporate fertilizer and pesticides, and provide loose soil for seed. Other …