Aerospace Medicine and Biology. A continuing bibliography with indexes

This bibliography lists 244 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1981. Aerospace medicine and aerobiology topics are included. Listings for physiological factors, astronaut performance, control theory, artificial intelligence, and cybernetics are included

Applications of aerospace technology in the public sector

Current activities of the program to accelerate specific applications of space related technology in major public sector problem areas are summarized for the period 1 June 1971 through 30 November 1971. An overview of NASA technology, technology applications, and supporting activities are presented. Specific technology applications in biomedicine are reported including cancer detection, treatment and research; cardiovascular diseases, diagnosis, and treatment; medical instrumentation; kidney function disorders, treatment, and research; and rehabilitation medicine

A Concept for Direct Control of Rotary Blood Pump Speed by Inlet Pressure

Heart failure remains a major health problem for the world. Heart transplantation is the most effective treatment for end stage heart failure. A major problem with heart transplantation is finding adequate numbers of appropriate donors. The lack of donor numbers in the world creates a significant clinical need for blood pumping devices. The ability of ventricular assist devices to relieve the consequences of less than terminal heart failure further creates a need for assist therapy. Current new ventricular assist devices are built around continuous flow technology. These nonpulsatile assist devices have had major clinical success in relieving symptoms and increasing patient survival. However they have a control issue as opposed the first generation pulsatile Ventricular Assist Devices (VADs) in that their output is sensitive to pressure difference, not primarily to inlet pressure. We have developed a rotodynamic blood pump speed management concept that results in a pump that responds to inlet pressure in a Starling law-like manner without active electronic controls or pressure sensors. The long term goal of this project is to develop a VAD system which responds as the natural human heart does. The pump speed is controlled by an adjunct electromechanical inlet conduit. The inlet conduit has 2 integrated cylinders. The inner cylinder is the blood flow pathway, and is flexible in order to expand/collapse in response to inlet blood pressure. The outer cylinder is used as the coil of a tank circuit. There is also a ferrofluid reservoir which is connected to the space between the 2 cylinders. The majority of ferrofluid is in the reservoir when inlet pressure is high, but ferrofluid flows into the core of the coil when inlet pressure is low. The inductance of the coil varies in response to the volume of the ferrofluid within the core. Therefore the natural frequency of the tank circuit varies and the impedance of the tank circuit changes. The control circuit is connected in series with the motor leads. Thus the voltag

A Concept for Direct Control of Rotary Blood Pump Speed by Inlet Pressure

Heart failure remains a major health problem for the world. Heart transplantation is the most effective treatment for end stage heart failure. A major problem with heart transplantation is finding adequate numbers of appropriate donors. The lack of donor numbers in the world creates a significant clinical need for blood pumping devices. The ability of ventricular assist devices to relieve the consequences of less than terminal heart failure further creates a need for assist therapy. Current new ventricular assist devices are built around continuous flow technology. These nonpulsatile assist devices have had major clinical success in relieving symptoms and increasing patient survival. However they have a control issue as opposed the first generation pulsatile Ventricular Assist Devices (VADs) in that their output is sensitive to pressure difference, not primarily to inlet pressure. We have developed a rotodynamic blood pump speed management concept that results in a pump that responds to inlet pressure in a Starling law-like manner without active electronic controls or pressure sensors. The long term goal of this project is to develop a VAD system which responds as the natural human heart does. The pump speed is controlled by an adjunct electromechanical inlet conduit. The inlet conduit has 2 integrated cylinders. The inner cylinder is the blood flow pathway, and is flexible in order to expand/collapse in response to inlet blood pressure. The outer cylinder is used as the coil of a tank circuit. There is also a ferrofluid reservoir which is connected to the space between the 2 cylinders. The majority of ferrofluid is in the reservoir when inlet pressure is high, but ferrofluid flows into the core of the coil when inlet pressure is low. The inductance of the coil varies in response to the volume of the ferrofluid within the core. Therefore the natural frequency of the tank circuit varies and the impedance of the tank circuit changes. The control circuit is connected in series with the motor leads. Thus the voltag

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 192

This bibliography lists 247 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1979

Technology applications

A summary of NASA Technology Utilization programs for the period of 1 December 1971 through 31 May 1972 is presented. An abbreviated description of the overall Technology Utilization Applications Program is provided as a background for the specific applications examples. Subjects discussed are in the broad headings of: (1) cancer, (2) cardiovascular disease, (2) medical instrumentation, (4) urinary system disorders, (5) rehabilitation medicine, (6) air and water pollution, (7) housing and urban construction, (8) fire safety, (9) law enforcement and criminalistics, (10) transportation, and (11) mine safety

Pulse Oximeter Calibrator

Initial calibration of pulse oximeters is conducted by inducing hypoxemia in healthy human volunteers to obtain blood oxygenation levels as low as 70%. This method of calibration is expensive and time consuming for pulse oximeter manufacturers. Eliminating the human element of calibration would reduce overall cost and save time. An artificial system was developed to simulate blood oxygenation levels between 70-100% and heart rate readings between 30-150 BPM. A programmed, motorized, dual-axis system was designed to provide certain calibration values as specified by the user through a computer interface. Tests conducted with the CMS50F Wrist Oximeter showed that values obtained from the calibrator fall within +/-4% oxygenation and +/-3 BPM heart rate from that of the user defined values

MODERNIZATION OF THE MOCK CIRCULATORY LOOP: ADVANCED PHYSICAL MODELING, HIGH PERFORMANCE HARDWARE, AND INCORPORATION OF ANATOMICAL MODELS

A systemic mock circulatory loop plays a pivotal role as the in vitro assessment tool for left heart medical devices. The standard design employed by many research groups dates to the early 1970\u27s, and lacks the acuity needed for the advanced device designs currently being explored. The necessity to update the architecture of this in vitro tool has become apparent as the historical design fails to deliver the performance needed to simulate conditions and events that have been clinically identified as challenges for future device designs. In order to appropriately deliver the testing solution needed, a comprehensive evaluation of the functionality demanded must be understood. The resulting system is a fully automated systemic mock circulatory loop, inclusive of anatomical geometries at critical flow sections, and accompanying software tools to execute precise investigations of cardiac device performance. Delivering this complete testing solution will be achieved through three research aims: (1) Utilization of advanced physical modeling tools to develop a high fidelity computational model of the in vitro system. This model will enable control design of the logic that will govern the in vitro actuators, allow experimental settings to be evaluated prior to execution in the mock circulatory loop, and determination of system settings that replicate clinical patient data. (2) Deployment of a fully automated mock circulatory loop that allows for runtime control of all the settings needed to appropriately construct the conditions of interest. It is essential that the system is able to change set point on the fly; simulation of cardiovascular dynamics and event sequences require this functionality. The robustness of an automated system with incorporated closed loop control logic yields a mock circulatory loop with excellent reproducibility, which is essential for effective device evaluation. (3) Incorporating anatomical geometry at the critical device interfaces; ascending aorta and left atrium. These anatomies represent complex shapes; the flows present in these sections are complex and greatly affect device performance. Increasing the fidelity of the local flow fields at these interfaces delivers a more accurate representation of the device performance in vivo