Biological and Medical Experiments on the Space Shuttle, 1981 - 1985

This volume is the first in a planned series of reports intended to provide a comprehensive record of all the biological and medical experiments and samples flown on the Space Shuttle. Experiments described have been conducted over a five-year period, beginning with the first plant studies conducted on STS-2 in November 1981, and extending through STS 61-C, the last mission to fly before the tragic Challenger accident of January 1986. Experiments were sponsored within NASA not only by the Life Sciences Division of the Office of Space Science and Applications, but also by the Shuttle Student Involvement Program (SSIP) and the Get Away Special (GAS) Program. Independent medical studies were conducted as well on the Shuttle crew under the auspices of the Space Biomedical Research Institute at Johnson Space Center. In addition, cooperative agreements between NASA and foreign government agencies led to a number of independent experiments and also paved the way for the joint US/ESA Spacelab 1 mission and the German (DFVLR) Spacelab D-1. Experiments included: (1) medically oriented studies of the crew aimed at identifying, preventing, or treating health problems due to space travel; (2) projects to study morphological, physiological, or behavioral effects of microgravity on animals and plants; (3) studies of the effects of microgravity on cells and tissues; and (4) radiation experiments monitoring the spacecraft environment with chemical or biological dosimeters or testing radiation effects on simple organisms and seeds

Vital sign monitoring and cardiac triggering at 1.5 Tesla: A practical solution by an MR-ballistocardiography fiber-optic sensor

This article presents a solution for continuous monitoring of both respiratory rate (RR) and heart rate (HR) inside Magnetic Resonance Imaging (MRI) environments by a novel ballistocardiography (BCG) fiber-optic sensor. We designed and created a sensor based on the Fiber Bragg Grating (FBG) probe encapsulated inside fiberglass (fiberglass is a composite material made up of glass fiber, fabric, and cured synthetic resin). Due to this, the encapsulation sensor is characterized by very small dimensions (30 x 10 x 0.8 mm) and low weight (2 g). We present original results of real MRI measurements (conventionally most used 1.5 T MR scanner) involving ten volunteers (six men and four women) by performing conventional electrocardiography (ECG) to measure the HR and using a Pneumatic Respiratory Transducer (PRT) for RR monitoring. The acquired sensor data were compared against real measurements using the objective Bland-Altman method, and the functionality of the sensor was validated (95.36% of the sensed values were within the +/- 1.96 SD range for the RR determination and 95.13% of the values were within the +/- 1.96 SD range for the HR determination) by this means. The accuracy of this sensor was further characterized by a relative error below 5% (4.64% for RR and 4.87% for HR measurements). The tests carried out in an MRI environment demonstrated that the presence of the FBG sensor in the MRI scanner does not affect the quality of this imaging modality. The results also confirmed the possibility of using the sensor for cardiac triggering at 1.5 T (for synchronization and gating of cardiovascular magnetic resonance) and for cardiac triggering when a Diffusion Weighted Imaging (DWI) is used.Web of Science193art. no. 47

Development of a Portable Seat Cushion for the Estimation of Heart Rate Using Ballistocardiography

Cardiovascular diseases are a leading contributor of health problems all over the world and are the second leading cause of death. They are also the cause of significant economic burden, costing billions of dollars in healthcare every year. With an aging population, the strain on the healthcare system, both in terms of costs and care provision, is expected to worsen. Frequent cardiac assessment can provide essential information towards diagnosis, monitoring, and treatment, which can mitigate symptoms and improve health outcomes for people with conditions such as heart failure. This has led to increasing interest in cardiac assessment at home. Additionally, for some populations like people with limited mobility and older adults, long term vitals monitoring at a clinical setting is not feasible, making at-home monitoring more viable and economical. Most devices available for cardiac monitoring at home are wearables. While wearable technology can be accurate, it requires compliance and maintenance, which is not an ideal solution for all populations. For example, people who are not comfortable using wearables or people with a cognitive impairment may not want or be able to use wearables, which could exclude these user types from at home monitoring. Keeping these factors under consideration, the past decade has seen an increased interest in the development of technologies for Ambient Assisted Living (i.e., smart technologies integrated into a user's environment). These technologies have the potential for ongoing health monitoring in an unobtrusive manner. This thesis presents research into the development of a smart seat cushion for heart rate monitoring. The cushion is able to calculate the heart rate of a person seated on it by acquiring their Ballistocardiogram (BCG). BCG is a cardiovascular signal corresponding to the displacement of the body in response to the heart pumping blood at every heartbeat. The prototype seat cushion has load cells embedded inside it that sense the micromovements of the body and translate it to an electrical signal. An analog signal conditioning circuit amplifies and filters this signal to enhance the components corresponding to BCG before it is converted to digital form. A pilot study was conducted with twenty participants to acquire BCG in real-world scenarios: 1) sitting still, 2) reading, 3) using a computer, 4) watching TV, and 5) having a conversation. Heart rate was calculated using a novel algorithm based on Continuous Wavelet Transform by detecting the largest peaks (referred to as the J-peaks) in the BCG. Excluding three outliers, the algorithm is able to achieve an overall accuracy of 94.6% compared to gold standard Electrocardiography (ECG). This accuracy is observed to be as good as or better than those of existing wearable heart rate monitors. The seat cushion developed in this thesis research can serve as a portable solution for cardiac monitoring and can integrate into an ambient health monitoring system, offering continued monitoring of heart rate while requiring no perceived effort to operate it. Future work includes exploring different sensor configurations, machine learning based approaches for improving J-peaks detection, and real-time monitoring of heart rate

Assessment of vertical treadmill running under different levels of simulated gravity, using a vertical treadmill facility with a subject loading system (Avatar)

Introduction: Prolonged exposure to microgravity during spaceflights leads to severe deconditioning in the physical performance of astronauts that affects dangerously crew health and safety during mission critical maneuvers. To understand the effectiveness of the existing inflight daily countermeasures, treadmill running in simulated microgravity under different levels of adjusted g-load is compared to usual treadmill running on earth. Methods: For purposes of exercise planning onboard the ISS, the objective of this study was to assess the oxygen uptake under using spiroergometric assessment of men and women (n=26, 8 female and 6 male 20- 30 years; 6 male and 6 female 50-60 years) during running on an horizontal treadmill and on a vertical treadmill under different levels of simulated gravity with the Vertical Treadmill Facility (VTF) and Subject loading system (SLS) from the European Space Agency (ESA) and took place in the Physiology Laboratory of the institute of Aerospace Medicine at the Department of Space physiology at the German Space Center (DLR) in Cologne, Germany. After assessing the maximum oxygen uptake using the Bruce-protocol on the horizontal treadmill, an incremental running protocol on both the vertical and horizontal treadmill was performed in randomized order, starting at a speed of 4 kph and increasing every 4 min by 2.5 kph to a maximum of 19 kph. The runs on the vertical treadmill are performed under 0.3g, 0.6g and 1 g of body weight. Results: 26 Subjects were included with a total of 93 runs (9 of 102 runs excluded). The maximum speed was greater for 0.3g and for 0.6g on the vertical treadmill (P < 0.001, see Table above) than on the horizontal treadmill. By contrast, peak oxygen uptake was greater for the horizontal treadmill than for all conditions on the vertical treadmill (P < 0.001), and so was maximal heart rate (P < 0.05). Conclusion: The reduction in peak oxygen uptake on the vertical treadmill was strikingly similar across the three simulated gravity conditions and cannot be explained by inability to run faster. Rather, gravity-related impediment of gas exchange, or impediment of perfusion in horizontal position can be suspected. If this should be the case, then this would constitute a substantial limitation to exercise in space

Aerospace Medicine and Biology: A continuing Bibliography with Indexes

This bibliography lists 205 reports, articles, and other documents introduced into the NASA scientific and technical information system in October 1985

Spacelab mission 1 experiment descriptions, third edition

Experiments and facilities selected for flight on the first Spacelab mission are described. Chosen from responses to the Announcement of Opportunity for the Spacelab 1 mission, the experiments cover five broad areas of investigation: atmospheric physics and Earth observations; space plasma physics; astronomy and solar physics; material sciences and technology; and life sciences. The name of the principal investigator and country is listed for each experiment

Development of a bed-based nighttime monitoring toolset

Doctor of PhilosophyDepartment of Electrical and Computer EngineeringSteven WarrenA movement is occurring within the healthcare field towards evidence-based or preventative care-based medicine, which requires personalized monitoring solutions. For medical technologies to fit within this framework, they need to adapt. Reduced cost of operation, ease-of-use, durability, and acceptance will be critical design considerations that will determine their success. Wearable technologies have shown the capability to monitor physiological signals at a reduced cost, but they require consistent effort from the user. Innovative unobtrusive and autonomous monitoring technologies will be needed to make personalized healthcare a reality. Ballistocardiography, a nearly forgotten field, has reemerged as a promising alternative for unobtrusive physiological monitoring. Heart rate, heart rate variability, respiration rate, movement, and additional hemodynamic features can be estimated from the ballistocardiogram (BCG). This dissertation presents a bed-based nighttime monitoring toolset designed to monitor BCG, respiration, and movement data motivated by the need to quantify the sleep of children with severe disabilities and autism – a capability currently unmet by commercial systems. A review of ballistocardiography instrumentation techniques (Chapter 2) is presented to 1) build an understanding of how the forces generated by the heart are coupled to the measurement apparatus and 2) provide a background of the field. The choice of sensing modalities and acquisition hardware and software for developing the unobtrusive bed-based nighttime monitoring platform is outlined in Chapters 3 and 4. Preliminary results illustrating the system’s ability to track physiological signals are presented in Chapter 5. Analyses were conducted on overnight data acquired from three lower-functioning children with autism (Chapters 6 and 9) who reside at Heartspring, Wichita, KS, where results justified the platform’s multi-sensor architecture and demonstrated the system’s ability to track physiological signals from this sensitive population over many months. Further, this dissertation presents novel BCG signal processing techniques – a signal quality index (Chapter 7) and a preprocessing inverse filter (Chapter 8) that are applicable to any ballistocardiograph. The bed-based nighttime monitoring toolset outlined in this dissertation presents an unobtrusive, autonomous, robust physiological monitoring system that could be used in hospital-based or personalized, home-based medical applications that consist of short or long-term monitoring scenarios