Direct Signal-to-Noise Quality Comparison between an Electronic and Conventional Stethoscope aboard the International Space Station

Introduction: Evaluation of heart, lung, and bowel sounds is routinely performed with the use of a stethoscope to help detect a broad range of medical conditions. Stethoscope acquired information is even more valuable in a resource limited environments such as the International Space Station (ISS) where additional testing is not available. The high ambient noise level aboard the ISS poses a specific challenge to auscultation by stethoscope. An electronic stethoscope's ambient noisereduction, greater sound amplification, recording capabilities, and sound visualization software may be an advantage to a conventional stethoscope in this environment. Methods: A single operator rated signaltonoise quality from a conventional stethoscope (Littman 2218BE) and an electronic stethoscope (Litmann 3200). Borborygmi, pulmonic, and cardiac sound quality was ranked with both stethoscopes. Signaltonoise rankings were preformed on a 1 to 10 subjective scale with 1 being inaudible, 6 the expected quality in an emergency department, 8 the expected quality in a clinic, and 10 the clearest possible quality. Testing took place in the Japanese Pressurized Module (JPM), Unity (Node 2), Destiny (US Lab), Tranquility (Node 3), and the Cupola of the International Space Station. All examinations were conducted at a single point in time. Results: The electronic stethoscope's performance ranked higher than the conventional stethoscope for each body sound in all modules tested. The electronic stethoscope's sound quality was rated between 7 and 10 in all modules tested. In comparison, the traditional stethoscope's sound quality was rated between 4 and 7. The signal to noise ratio of borborygmi showed the biggest difference between stethoscopes. In the modules tested, the auscultation of borborygmi was rated between 5 and 7 by the conventional stethoscope and consistently 10 by the electronic stethoscope. Discussion: This stethoscope comparison was limited to a single operator. However, we believe the results are noteworthy. The electronic stethoscope out preformed the traditional stethoscope in each direct comparison. Consideration should be made to incorporate an electronic stethoscope into current and future space vehicle medical kits

Smart Ultrasound Remote Guidance Experiment (SURGE) Preliminary Findings

To date, diagnostic quality ultrasound images were obtained aboard the International Space Station (ISS) using the ultrasound of the Human Research Facility (HRF) rack in the Laboratory module. Through the Advanced Diagnostic Ultrasound in Microgravity (ADUM) and the Braslet-M Occlusion Cuffs (BRASLET SDTO) studies, non-expert ultrasound operators aboard the ISS have performed cardiac, thoracic, abdominal, vascular, ocular, and musculoskeletal ultrasound assessments using remote guidance from ground-based ultrasound experts. With exploration class missions to the lunar and Martian surfaces on the horizon, crew medical officers will necessarily need to operate with greater autonomy given communication delays (round trip times of up to 5 seconds for the Moon and 90 minutes for Mars) and longer periods of communication blackouts (due to orbital constraints of communication assets). The SURGE project explored the feasibility and training requirements of having non-expert ultrasound operators perform autonomous ultrasound assessments in a simulated exploration mission outpost. The project aimed to identify experience, training, and human factors requirements for crew medical officers to perform autonomous ultrasonography. All of these aims pertained to the following risks from the NASA Bioastronautics Road Map: 1) Risk 18: Major Illness and Trauna; 2) Risk 20) Ambulatory Care; 3) Risk 22: Medical Informatics, Technologies, and Support Systems; and 4) Risk 23: Medical Skill Training and Maintenance

Large Area Mapping at 850 Microns. V. Analysis of the Clump Distribution in the Orion A South Molecular Cloud

We present results from a 2300 arcmin^2 survey of the Orion A molecular cloud at 450 and 850 micron using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. The region mapped lies directly south of the OMC1 cloud core and includes OMC4, OMC5, HH1/2, HH34, and L1641N. We identify 71 independent clumps in the 850 micron map and compute size, flux, and degree of central concentration in each. Comparison with isothermal, pressure-confined, self-gravitating Bonnor-Ebert spheres implies that the clumps have internal temperatures T_d ~ 22 +/- K and surface pressures log (k^-1 P cm^-3 K) = 6.0 +/- 0.2. The clump masses span the range 0.3 - 22 Msun assuming a dust temperature T_d ~ 20 K and a dust emissivity kappa_850 = 0.02 cm^2 g^-1. The distribution of clump masses is well characterized by a power-law N(M) propto M^-alpha with alpha = 2.0 +/- 0.5 for M > 3.0 Msun, indicating a clump mass function steeper than the stellar Initial Mass Function. Significant incompleteness makes determination of the slope at lower masses difficult. A comparison of the submillimeter emission map with an H_2 2.122 micron survey of the same region is performed. Several new Class 0 sources are revealed and a correlation is found between both the column density and degree of concentration of the submillimeter sources and the likelihood of coincident H_2 shock emission.Comment: 44 pages, 17 figures, accepted by Ap

The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud

We present an analysis of ~3.5 square degrees of submillimetre continuum and extinction data of the Perseus molecular cloud. We identify 58 clumps in the submillimetre map and we identify 39 structures (`cores') and 11 associations of structures (`super cores') in the extinction map. The cumulative mass distributions of the submillimetre clumps and extinction cores have steep slopes (alpha ~ 2 and 1.5 - 2 respectively), steeper than the Salpeter IMF (alpha = 1.35), while the distribution of extinction super cores has a shallow slope (alpha ~ 1). Most of the submillimetre clumps are well fit by stable Bonnor-Ebert spheres with 10K < T < 19K and 5.5 < log_10(P_ext/k) < 6.0. The clumps are found only in the highest column density regions (A_V > 5 - 7 mag), although Bonnor-Ebert models suggest that we should have been able to detect them at lower column densities if they exist. These observations provide a stronger case for an extinction threshold than that found in analysis of less sensitive observations of the Ophiuchus molecular cloud. The relationship between submillimetre clumps and their parent extinction core has been analyzed. The submillimetre clumps tend to lie offset from the larger extinction peaks, suggesting the clumps formed via an external triggering event, consistent with previous observations.Comment: 38 pages, 12 figures, accepted by Astrophysical Journal slight changes to original due to a slight 3" error in the coordinates of the SCUBA ma

Direct Signal-to-Noise Quality Comparison Between an Electronic aud Conventional Stethoscope Aboard the International Space Station

No abstract availabl

Large Area Mapping at 850 Microns. IV. Analysis of the Clump Distribution in the Orion B South Molecular Cloud

We present results from a survey of a 1300 arcmin^2 region of the Orion B South molecular cloud, including NGC 2024, NGC 2023, and the Horsehead Nebula (B33), obtained using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. Submillimeter continuum observations at 450 microns and 850 microns are discussed. Using an automated algorithm, 57 discrete emission features (``clumps'') are identified in the 850 micron map. The physical conditions within these clumps are investigated under the assumption that the objects are in quasi-hydrostatic equilibrium. The best fit dust temperature for the clumps is found to be T_d = 18 +/- 4 K, with the exception of those associated with the few known far infrared sources residing in NGC 2024. The latter internally heated sources are found to be much warmer. In the region surrounding NGC 2023, the clump dust temperatures agree with clump gas temperatures determined from molecular line excitation measurements of the CO molecule. The bounding pressure on the clumps lies in the range log(k^-1 P cm^3 K^-1) = 6.1 +/- 0.3. The cumulative mass distribution is steep at the high mass end, as is the stellar Initial Mass Function. The distribution flattens significantly at lower masses, with a turn-over around 3 -- 10 M_sun.Comment: 41 pages, 16 figures, accepted by Ap

Dense Gas Tracers in Perseus: Relating the N2H+, NH3, and Dust Continuum Properties of Pre- and Proto-Stellar Cores

We investigate 35 pre-stellar cores and 36 proto-stellar cores in the Perseus molecular cloud. We find a very tight correlation between the physical parameters describing the N2H+ and NH3 gas. Both the velocity centroids and the line widths of N2H+ and NH3 correlate much better than either species correlates with CO, as expected if the nitrogen-bearing species are probing primarily the dense core gas where the CO has been depleted. We also find a tight correlation in the inferred abundance ratio between N2H+ and para-NH3 across all cores, with N(p-NH3)/N(N2H+)= 22 +/- 10. We find a mild correlation between NH3 (and N2H+) column density and the (sub)millimeter dust continuum derived H2 column density for pre-stellar cores, N(p-NH3)/N(H2) ~ 10e-8, but do not find a fixed ratio for proto-stellar cores. The observations suggest that in the Perseus molecular cloud the formation and destruction mechanisms for the two nitrogen-bearing species are similar, regardless of the physical conditions in the dense core gas. While the equivalence of N2H+ and NH3 as powerful tracers of dense gas is validated, the lack of correspondence between these species and the (sub)millimeter dust continuum observations for proto-stellar cores is disconcerting and presently unexplained.Comment: ApJ accepted. 45 pages, 8 figure

Submacular Choroid Thickness Increases During Long-Duration Spaceflight

The Spaceflight Associated Neuro-ocular Syndrome (SANS) is characterized by the development of optic disc edema, choroidal folds, cotton-wool spots, globe flattening, and/or refractive error changes greater than or equal to 0.75D during long-duration spaceflight to the International Space Station (ISS). It is hypothesized that these findings result from the headward fluid shift that occurs due to weightlessness. We can induce a headward fluid shift on Earth using positional changes and on ISS due to weightlessness. Lower-body negative pressure (LBNP) is used to reverse the headward fluid shift by drawing fluid into the lower body and can be used on Earth and on ISS

Clinical Outcome Metrics for Optimization of Robust Training

The objective of this research is to develop and use clinical outcome metrics and training tools to quantify the differences in performance of a physician vs nonphysician crew medical officer (CMO) analogues during simulations

Clinical Outcome Metrics for Optimization of Robust Training

Develop and use clinical outcome metrics and training tools to quantify performance differences of physician vs. non-physician crew medical officer (CMO) analogs during simulations