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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Biofeedback With Implanted Blood-Pressure Device

Additional uses found for equipment described in "Implanted Blood-Pressure-Measuring Device" (GSC-13042). Implanted with device electronic circuitry that measures, interprets, and transmits data via inductive link through patient's skin to external receiver. Receiver includes audible alarm generator activated when patient's blood pressure exceeds predetermined threshold. Also included in receiver a blood-pressure display, recorder, or both, for use by patient or physician.

Rischell, Robert E.↗
NASA NTRS1988

Physiology of prolonged bed rest

Bed rest has been a normal procedure used by physicians for centuries in the treatment of injury and disease. Exposure of patients to prolonged bed rest in the horizontal position induces adaptive deconditioning responses. While deconditioning responses are appropriate for patients or test subjects in the horizontal position, they usually result in adverse physiological responses (fainting, muscular weakness) when the patient assume the upright posture. These deconditioning responses result from reduction in hydrostatic pressure within the cardiovascular system, virtual elimination of longitudinal pressure on the long bones, some decrease in total body metabolism, changes in diet, and perhaps psychological impact from the different environment. Almost every system in the body is affected. An early stimulus is the cephalic shift of fluid from the legs which increases atrial pressure and induces compensatory responses for fluid and electrolyte redistribution. Without countermeasures, deterioration in strength and muscle function occurs within 1 wk while increased calcium loss may continue for months. Research should also focus on drug and carbohydrate metabolism.

Greenleaf, J. E.↗
NASA NTRS1989

Biomedical Telectrodes

Compact transmitters eliminate need for wires to monitors. Biomedical telectrode is small electronic package that attaches to patient in manner similar to small adhesive bandage. Patient wearing biomedical telectrodes moves freely, without risk of breaking or entangling wire connections. Especially beneficial to patients undergoing electrocardiographic monitoring in intensive-care units in hospitals. Eliminates nuisance of coping with wire connections while dressing and going to toilet.

Shepherd, C. K.↗
NASA NTRS1987

Diet and the role of lipoproteins, lipases, and thyroid hormones in coronary lesion growth

The relationships between the coronary lesion growth and the blood contents of lipoprotein fractions, thyroic hormones, and the lipoprotein lipase activity were investigated in male patients with severe coronary atherosclerosis, who participated in a lipid-lowering dietary intervention program. A quantitative computer-assisted image-processing technique was used to assess the severity of coronary obstructions at the beginning of the program and at its termination two years later. Based on absolute coronary scores, patients were divided into a no-lesion growth group (14 patients) and a progression group (21 paients). At the end of the trial, the very-low-density lipoprotein cholesterol and triglycerides were found to be significantly higher, while the high-density lipoprotein cholesterol and hepatic lipase (HL) were lower in the progression group. Multivariate regression analysis showed HL to be the most important determinant of changes in coronary atherosclerotic lesions.

Barth, Jacques D.↗
NASA NTRS1991

Ultrasonic Device Monitors Fullness Of The Bladder

Ultrasonic device monitors fullness of bladder is self-contained, lightweight, portable, powered by battery, and tailored for specific patient through software modified as patient's behavior changes. Essentially quantifies amount of urine in bladder by measuring relative distension of bladder and gives suitable alarm telling patient to eliminate. Intended for use in training people who are incontinent and cannot identify when elimination necessary.

Heyman, Joseph S.↗
NASA NTRS1991

Neural-Network Control Of Prosthetic And Robotic Hands

Electronic neural networks proposed for use in controlling robotic and prosthetic hands and exoskeletal or glovelike electromechanical devices aiding intact but nonfunctional hands. Specific to patient, who activates grasping motion by voice command, by mechanical switch, or by myoelectric impulse. Patient retains higher-level control, while lower-level control provided by neural network analogous to that of miniature brain. During training, patient teaches miniature brain to perform specialized, anthropomorphic movements unique to himself or herself.

Buckley, Theresa M.↗
NASA NTRS1987

Comparison of smooth pursuit and combined eye-head tracking in human subjects with deficient labyrinthine function

The effects of deficient labyrinthine function on smooth visual tracking with the eyes and head were investigated, using ten patients with bilateral peripheral vestibular disease and ten normal controls. Active, combined eye-head tracking (EHT) was significantly better in patients than smooth pursuit with the eyes alone, whereas normal subjects pursued equally well in both cases. Compensatory eye movements during active head rotation in darkness were always less in patients than in normal subjects. These data were used to examine current hypotheses that postulate central cancellation of the vestibulo-ocular reflex (VOR) during EHT. A model that proposes summation of an integral smooth pursuit command and VOR/compensatory eye movements is consistent with the findings. Observation of passive EHT (visual fixation of a head-fixed target during en bloc rotation) appears to indicate that in this mode parametric gain changes contribute to modulation of the VOR.

Leigh, R. J.↗
NASA NTRS1992

The locator system for wandering individuals

Configurations and operation strategies are described for a wanderer locator system based on wireless radio frequency communication designed to monitor elderly patients who may wander beyond safe perimeters in the home or in an institutional setting. The modular components of this wandering notification system are (1) portable transmitter/receivers to be worn or carried by the patient and the caretaker, (2) detectors to be mounted in doorways or other perimeters of a safe area, (3) programmable central processing units to control, communicate with, and/or trace the portable and remote devices, and (4) a cathode ray tube that can display information on patient location or system status. Photographs of all system components and illustrations of operations concepts are included.

Davidson, Shayla↗
NASA NTRS1993

Measuring the metastatic potential of cancer cells

Cancer cells must secrete proteolytic enzymes to invade adjacent tissues and migrate to a new metastatic site. Urokinase (uPA) is a key enzyme related to metastasis in cancers of the lung, colon, gastric, uterine, breast, brain, and malignant melanoma. A NASA technology utilization project has combined fluorescence microscopy, image analysis, and flow cytometry, using fluorescent dyes, and urokinase-specific antibodies to measure uPA and abnormal DNA levels (related to cancer cell proliferation) inside the cancer cells. The project is focused on developing quantitative measurements to determine if a patient's tumor cells are actively metastasizing. If a significant number of tumor cells contain large amounts of uPA (esp. membrane-bound) then the post-surgical chemotherapy or radiotherapy can be targeted for metastatic cells that have already left the primary tumor. These analytical methods have been applied to a retrospective study of biopsy tissues from 150 node negative, stage 1 breast cancer patients. Cytopathology and image analysis has shown that uPA is present in high levels in many breast cancer cells, but not found in normal breast. Significant amounts of uPA also have been measured in glioma cell lines cultured from brain tumors. Commercial applications include new diagnostic tests for metastatic cells, in different cancers, which are being developed with a company that provides a medical testing service using flow cytometry for DNA analysis and hormone receptors on tumor cells from patient biopsies. This research also may provide the basis for developing a new 'magic bullet' treatment against metastasis using chemotherapeutic drugs or radioisotopes attached to urokinase-specific monoclonal antibodies that will only bind to metastatic cells.

Morrison, Dennis R.↗
NASA NTRS1994

Helium-ion-induced human cataractogenesis

Retrospective and ongoing analyses of clinical records from 347 primary intraocular melanoman patients treated with helium ions at Lawrence Berkeley Laboratory (LBL) will allow examination of the exposure-response data for human cataract; which is a complication of the therapy from incidental exposure of the lens. Direct particle beam traversal of at least a portion of the lens usually is unavoidable in treatment of posterior intraocular tumors. The precise treatment planned for each patient permits quantitative assessment of the lenticular dose and its radiation quality. We are reporting our preliminary results on the development of helium-ion-induced lens opacifications and cataracts in 54 of these patients who had 10% or less of their lens in the treatment field. We believe these studies will be relevant to estimating the human risk for cataract in space flight.

Blakely, E. A.↗
NASA NTRS1992

Advanced Cardiac Life Support (ACLS) utilizing Man-Tended Capability (MTC) hardware onboard Space Station Freedom

Because of the time and distance involved in returning a patient from space to a definitive medical care facility, the capability for Advanced Cardiac Life Support (ACLS) exists onboard Space Station Freedom. Methods: In order to evaluate the effectiveness of terrestrial ACLS protocols in microgravity, a medical team conducted simulations during parabolic flights onboard the KC-135 aircraft. The hardware planned for use during the MTC phase of the space station was utilized to increase the fidelity of the scenario and to evaluate the prototype equipment. Based on initial KC-135 testing of CPR and ACLS, changes were made to the ventricular fibrillation algorithm in order to accommodate the space environment. Other constraints to delivery of ACLS onboard the space station include crew size, minimum training, crew deconditioning, and limited supplies and equipment. Results: The delivery of ACLS in microgravity is hindered by the environment, but should be adequate. Factors specific to microgravity were identified for inclusion in the protocol including immediate restraint of the patient and early intubation to insure airway. External cardiac compressions of adequate force and frequency were administered using various methods. The more significant limiting factors appear to be crew training, crew size, and limited supplies. Conclusions: Although ACLS is possible in the microgravity environment, future evaluations are necessary to further refine the protocols. Proper patient and medical officer restraint is crucial prior to advanced procedures. Also emphasis should be placed on early intubation for airway management and drug administration. Preliminary results and further testing will be utilized in the design of medical hardware, determination of crew training, and medical operations for space station and beyond.

Smith, M.↗
NASA NTRS1995

Head perturbations during walking while viewing a head-fixed target

Inexpensive, head-fixed computer displays are now available that subjects can wear during locomotion. Our hypothesis is that viewing a head-fixed visual display will change the character- istics of rotational head perturbations during natural walking. Using a 3-axis angular rate sensor, we measured head rotations during natural or treadmill walking, in 10 normal subjects and 2 patients with deficient vestibular function, as they attempted to view (1) a stationary target at optical infinity; and (2) a target at a distance of 20 cm rigidly attached to the head. Normal subjects and patients showed no significant change in the predominant frequency of head rotations in any plane (ranging 0.7-5.7 Hz) during the two different viewing tasks. Mean peak head velocities also showed no difference during the two viewing conditions except in the yaw plane, in which values were greater while viewing the near target. Predominant frequencies of head rotations were similar in the pitch plane during natural or treadmill walking; however, peak velocities of pitch head rotations were substantially greater during natural walking. One vestibular patient showed modest increases of head velocity during natural walking compared with normal subjects. Rotational head perturbations that occur during natural walking are largely unaffected when subjects view a head-fixed target. There is need to study how such perturbations, which induce vestibular eye movements, affect vision of head-fixed displays.

Das, Vallabh E.↗
NASA NTRS1997

Neocytolysis Contributes to the Anemia of Renal Disease

Neocytolysis is a recently described physiologic process effecting selective hemolysis of young red blood cells in circumstances of plethora. Erythropoietin depression appears to initiate the process, providing rationale to investigate its contributions to the anemia of renal disease. When erythropoietin therapy was withheld, four of five stable hemodialysis patients demonstrated Cr-51 red cell survival patterns indicative of neocytolysis; red cell survival was short in the first 9 days, then normalized. Two of these patients received oral (13)C-glycine and (15)N-glycine and showed pathologic enrichment of stool porphyrins by the most recently ingested isotope when EPO therapy was held. This confirms selective hemolysis of newly-released red cells. (One patient had chronic hemolysis by isotope studies of blood and stool.) Thus, neocytolysis can contribute to the anemia of renal disease and explains some unresolved issues about such anemia. One implication is the prediction that intravenous bolus erythropoietin therapy is metabolically and economically inefficient compared to lower doses given more frequently subcutaneously.

Rice, Lawrence↗
NASA NTRS1997

Effective Documentation Tools

Quality assurance programs provide a very effective means to monitor and evaluate medical care. Quality assurance involves: (1) Identify a problem; (2) Determine the source and nature of the problem; (3) Develop policies and methods to effect improvement; (4) Implement those polices; (5) Monitor the methods applied; and (6) Evaluate their effectiveness. Because this definition of quality assurance so closely resembles the Nursing Process, the health unit staff was able to use their knowledge of the nursing process to develop many forms which improve the quality of patient care. These forms include the NASA DFRC Service Report, the occupational injury form (Incident Report), the patient survey (Pre-hospital Evaluation/Care Report), the Laboratory Log Sheet, the 911 Run Sheet, and the Patient Assessment Stamp. Examples and steps which are followed to generate these reports are described.

Sleboda, Claire↗
NASA NTRS1998

Role of Dendritic Cells in Immune Dysfunction

The specific aims of the project were: (1) Application of the NASA bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC). (2) Compare the frequency and function of DC in normal donors and immunocompromised cancer patients. (3) Analyze the effectiveness of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in a murine model of experimental fungal disease. Our investigations have provided new insight into DC immunobiology and have led to the development of methodology to evaluate DC in blood of normal donors and patients. Information gained from these studies has broadened our understanding of possible mechanisms involved in the immune dysfunction of space travelers and earth-bound cancer patients, and could contribute to the design of novel therapies to restore/preserve immunity in these individuals. Several new avenues of investigation were also revealed. The results of studies completed during Round 2 are summarized.

Savary, Cherylyn A.↗
NASA NTRS2000

Evaluation and Treatment of Essential Hypertension During Short Duration Space Flight

During the last four decades of manned space flight, two individuals have successfully flown in space with the preflight diagnosis of essential hypertension (HTN). Treatment of this disease process in the astronaut population warrants special consideration particularly when selecting medication for a mission. A retrospective review of data offers two different clinical scenarios involving the treatment, or lack thereof, for essential hypertension during space flight. Case I; A Caucasian quinquagenerian diagnosed with HTN one year prior to the mission obtained flight certification after a negative diagnostic workup. The patient was placed on a diuretic. Preflight isolated blood pressure (BP) measurements averaged 138/102. Inflight, the patient electively declined medication. A 36-hour BP monitor revealed an average value of 124/87. Postflight, BP measurements returned to preflight BP values. Case II: A Caucasian quatrogenerian diagnosed with HTN 6 months prior to launch completed flight training after a negative diagnostic workup. The patient was placed on an ACE inhibiter. Preflight BP measurements averaged 130/80. Inflight, isolated BP measurements were considerably less. Normotensive values were obtained postflight. In both cases, BP values inflight were lower than pre or postflight values. Yelle et al has confirmed similar findings in the normotensive astronaut population. Spaceflight may result in fluid shifting, mild dehydration, electrolyte imbalance, orthostatic hypotension, and increased heart rates. Based on these factors, certain classes of antihypertensive agents such as vasodilators, beta-blockers, and diuretics are excluded from consideration as a primary therapeutic modality. To date, Ace Inhibitors are viewed as the more acceptable drug of choice during spaceflight. Newer classes of drugs may also provide additional choices. Presently, astronauts developing uncomplicated HTN may continue their careers when treated with the appropriate class of continue their careers when treated with the appropriate class of antihypertensive medication.

Rossum, Alfred C.↗
NASA NTRS1999

Sensitivity of The Dynamic Visual Acuity Test To Sensorimotor Change

Post-flight astronauts, acutely post-vestibular nerve section patients, and patients with severe chronic bilateral vestibular deficits have oscillopsia caused by reduced vestibulocular reflex gains and decreased postural stability. Therefore, as previous work has shown, a test of dynamic visual acuity (DVA), in which the subject must read numbers from a computer screen while standing still or walking in place provides a composite measure of sensorimotor integration. This measure may be useful for determining the level of recovery, post-flight, post-operatively, or after vestibular rehabilitation. To determine the sensitivity of DVA to change in impaired populations we have tested patients with acoustic neuromas before and during the first post-operative week after resection of the tumors, and with bilaterally labyrinthine deficient subjects before and after six weeks of balance rehabilitation therapy.

Cohen, Helen↗
NASA NTRS1999

A Comparison of Cilostazol and Pentoxifylline for Treating Intermittent Claudication

A randomized, double-blind, placebo-controlled, parallel-group, phase III multicenter trial was performed to evaluate the relative efficacy and safety of cilostazol and pentoxifylline. The study included 54 outpatient vascular clinics, including sites at Air Force, Veterans Affairs, tertiary care, and university hospitals in the United States. Of 922 consenting patients, 698 met the inclusion criteria, were randomized, and received treatment with either cilostazol 100 mg P0 twice a day, pentoxifylline 400 mg PO 3 times a day, or placebo. Treatment was double-dummy to ensure study blindness. Efficacy was primarily established by maximal walking distance (MWD), measured with constant-speed, variable-grade treadmill testing, assessed at baseline and at 4, 8, 12, 16, 20, and 24 weeks. Mean MWD of cilostazol-treated patients (n=227) was significantly improved at every visit compared with patients who received pentoxifylline (n=232) or placebo (n=239). After 24 weeks of cilostazol, mean MWD increased 53.9% (107.3 m) from baseline, and the effect had not plateaued. This was better (P < 0.001) than the 30.4% (64.4 m) MWD improvement with pentoxifylline. MWD improvement with pentoxifylline was similar (P = 0.82) to that of placebo (64.7 m). Deaths and serious adverse event rates were similar in each group. Common side effects included headache (27.8% with cilostazol, 11.2% with pentoxifylline, 11.7% with placebo), palpitations (17.2% with cilostazol, 2.2% with pentoxifylllne, 1.3% with placebo), and abnormal stools. Cilostazol was significantly better than pentoxifylline or placebo for increasing walking distances; pentoxifylline was no better than placebo.

Dawson, David L.↗