Therapeutic Benefits of Short-Arm Human Centrifugation in Multiple Sclerosis–A New Approach

Short-arm human centrifugation (SAHC) is proposed as a robust countermeasure to treat deconditioning and prevent progressive disability in a case of secondary progressive multiple sclerosis. Based on long-term physiological knowledge derived from space medicine and missions, artificial gravity training seems to be a promising physical rehabilitation approach toward the prevention of musculoskeletal decrement due to confinement and inactivity. So, the present study proposes a novel infrastructure based on SAHC to investigate the hypothesis that artificial gravity ameliorates the degree of disability. The patient was submitted to a 4-week training programme including three weekly sessions of 30 min of intermittent centrifugation at 1.5–2 g. During sessions, cardiovascular, muscle oxygen saturation (SmO2) and electroencephalographic (EEG) responses were monitored, whereas neurological and physical performance tests were carried out before and after the intervention. Cardiovascular parameters improved in a way reminiscent of adaptations to aerobic exercise. SmO2 decreased during sessions concomitant with increased g load, and, as training progressed, SmO2 of the suffering limb dropped, both effects suggesting increased oxygen use, similar to that seen during hard exercise. EEG showed increased slow and decreased fast brain waves, with brain reorganization/plasticity evidenced through functional connectivity alterations. Multiple-sclerosis-related disability and balance capacity also improved. Overall, this study provides novel evidence supporting SAHC as a promising therapeutic strategy in multiple sclerosis, based on mechanical loading, thereby setting the basis for future randomized controlled trials.

Design suggestions on modified self-sustainable space toilet

The present research investigates the design of compact and lightweight waste collection system (WCS) for interplanetary missions such as Mars, and the Moon as well as the space with the required features of NASA’s lunar loo challenge (released date: 25th June, 2020). Existing space toilets’ WCS store waste in small plastic bags and these bags are thrown in the space which increases the space junk. If these WCS are used on planets, they could pollute the planets. The newly designed—unisex and self-sustainable space toilet meets its objective of intimacy and warmth for the astronauts as it is equipped with all essential features such as (a) the basin for vomit collection, (b) the rotating waste storage based on the mechanism of artificial gravity, and (c) the noiseless bellow pump for air flow flushing system (AFFS). The WCS is designed for the storage of urine, faeces, vomit, diarrhoea, and menses. In the first half of the research article, the focus is kept on improving self-sustainability of the present WCS. In the second half of the present investigation analyses are done for multiphase flows of the CFD analysis in ANSYS fluent to simulate the flow of air through the nozzle provided with (a) the seat, (b) the urine funnel, and (c) the basin for air flow flushing system (AFFS). The design of the present self-sustainable space toilet proposed herewith is justified suitable for different gravitational conditions such as (a) Mars (3.721 m/s2), (b) the Moon (1.62 m/s2), and (c) the zero—or microgravity i.e., the space gravity. The proposed solar-operated WCS could be integrated to function with (a) water recovery and management (WRM) system, (b) the inbuilt composting unit, and (c) the bioregenerative life support system (BLSS). Furthermore, the assessment of the required electrical energy derived from the solar energy (harnessed using efficient solar photovoltaic (PV) modules) is conceptualized for the effective functioning of the present self-sustainable WCS. Article highlights The present investigation explores into the design of lightweight and compact WCS for interplanetary missions such as Mars and the Moon, as well as space missions with the functionality listed by NASA's lunar toilet competition (released date: 25th June, 2020). The actual space toilets, which are used on the International Space Station (ISS), are not designed to withstand varying gravity circumstances. The new advanced—unisex and self-sustaining space toilet achieves its goal of intimacy and warmth for astronauts by including all necessary features such as (a) a vomit collection basin, (b) rotating waste storage based on artificial gravity mechanism, and (c) a noiseless bellow pump for air flow flushing system (AFFS).

Predicting individual acclimation to the cross-coupled illusion for artificial gravity

BACKGROUND: The cross-coupled (CC) illusion and associated motion sickness limits the tolerability of fast-spin-rate centrifugation for artificial gravity implementation. Humans acclimate to the CC illusion through repeated exposure; however, substantial inter-individual differences in acclimation exist, which remain poorly understood. To address this, we investigated several potential predictors of individual acclimation to the CC illusion. METHODS: Eleven subjects were exposed to the CC illusion for up to 50 25-minute acclimation sessions. The metric of acclimation rate was calculated as the slope of each subject’s linear increase in spin rate across sessions. As potential predictors of acclimation rate, we gathered age, gender, demographics, and activity history, and measured subjects’ vestibular perceptual thresholds in the yaw, pitch, and roll rotation axes. RESULTS: We found a significant, negative correlation (p = 0.025) between subjects’ acclimation rate and roll threshold, suggesting lower thresholds yielded faster acclimation. Additionally, a leave-one-out cross-validation analysis indicated that roll thresholds are predictive of acclimation rates. Correlations between acclimation and other measures were not found but were difficult to assess within our sample. CONCLUSIONS: The ability to predict individual differences in CC illusion acclimation rate using roll thresholds is critical to optimizing acclimation training, improving the feasibility of fast-rotation, short-radius centrifugation for artificial gravity.

Gluteal Muscle Atrophy and Increased Intramuscular Lipid Concentration Are Not Mitigated by Daily Artificial Gravity Following 60-Day Head-Down Tilt Bed Rest

Exposure to spaceflight and head-down tilt (HDT) bed rest leads to decreases in the mass of the gluteal muscle. Preliminary results have suggested that interventions, such as artificial gravity (AG), can partially mitigate some of the physiological adaptations induced by HDT bed rest. However, its effect on the gluteal muscles is currently unknown. This study investigated the effects of daily AG on the gluteal muscles during 60-day HDT bed rest. Twenty-four healthy individuals participated in the study: eight received 30 min of continuous AG; eight received 6 × 5 min of AG, interspersed with rest periods; eight belonged to a control group. T1-weighted Dixon magnetic resonance imaging of the hip region was conducted at baseline and day 59 of HDT bed rest to establish changes in volumes and intramuscular lipid concentration (ILC). Results showed that, across groups, muscle volumes decreased by 9.2% for gluteus maximus (GMAX), 8.0% for gluteus medius (GMED), and 10.5% for gluteus minimus after 59-day HDT bed rest (all p < 0.005). The ILC increased by 1.3% for GMAX and 0.5% for GMED (both p < 0.05). Neither of the AG protocols mitigated deconditioning of the gluteal muscles. Whereas all gluteal muscles atrophied, the ratio of lipids to intramuscular water increased only in GMAX and GMED muscles. These changes could impair the function of the hip joint and increased the risk of falls. The deconditioning of the gluteal muscles in space may negatively impact the hip joint stability of astronauts when reexpose to terrestrial gravity.

Novel Density-Based Autonomous Inflow Control Device Using Artificial Gravity

A new class of Autonomous Inflow Control Devices, AICDs, has been developed which balances production flow and restricts unwanted production fluids, even when there is no viscosity difference in the produced fluids. This novel AICD senses the density difference between oil and water and uses artificial gravity to amplify the buoyancy forces while eliminating the need for downhole orientation in the completion. AICDs have effectively reduced water production and increased oil recovery since their introduction in the early 2010s. During initial production, AICDs balance the flow across the production zone. In later production, AICDs automatically restrict the rate from zones producing water. Commercially available AICDs primarily operate by sensing the viscosity difference between oil and water. In very-light oil reservoirs, such as in parts of the Middle East, there is no significant viscosity difference. Previous density-based AICDs have been rejected because buoyancy forces are often overwhelmed by fluid forces and because they needed to be oriented with respect to Earth's gravity. Density-AICDs use floats that are buoyant in water and sink in oil to control fluid production. The key to the new density-AICD is that that the floats are housed in a spinning centrifugal rotor. This spinning density selector creates centripetal forces that multiply the buoyancy force thereby magnifying the difference between oil and water. The magnified buoyancy forces are stronger than fluid friction forces and are sufficient to overcome suction forces on the valve seats. The centripetal acceleration creates an artificial gravity that is much larger than Earth's gravity, eliminating the need to orient the density-AICD downhole. The density selector is spun by the production fluid so that larger centripetal forces are created in response to a larger drawdown. The result is a density-AICD that will operate in real-world conditions, especially in the light oil formations of the Middle East. The performance of this novel density-AICD has been measured in flow loop testing and demonstrated in computer modeling. The flow loop testing achieved substantial water restriction and continued oil flow using oil and water with identical viscosities.

Abstract P192: Orthostatic Tolerance Before And After 60 Days Of Strict Head Down Tilt Bedrest With And Without Daily Artificial Gravity Training

Background: Orthostatic intolerance occurs after space flight, immobilization and in patients with autonomic diseases, so there is a need for more effective countermeasures. We hypothesized that daily artificial gravity elicited through short-arm centrifugation attenuates plasma volume loss and orthostatic intolerance following 60 days of HDTBR, which models cardiovascular responses to weightlessness. Methods: We studied 24 healthy persons (8 women, 33.4±9.3 yr, 24.3±2.1 kg/m2) exposed to 60d HDTBR. Subjects were assigned to 30 min/d continuous short arm centrifugation (cAG), 6x5 min short arm centrifugation (iAG), or a control group (ctr, no countermeasures). Head-up tilt testing (15 min of 80°) followed by incremental lower body negative pressure (-10 mmHg every 3 min) until presyncope was performed before and at the end of HDTBR. Plasma volume was measured (CO rebreathing) 12-2 days before and after 56d of HDTBR. Stroke volume was measured by cMRI. Norepinephrine, epinephrine, aldosterone, and renine plasma levels were measured before and after HDTBR. Results: Time to presyncope decreased in all groups following bedrest (ctr: 22:56 min pre and 9:35 min post, cAG 15:34 min pre and 10:11 min post; iAG 14:56 min pre and 10:00 min post, p<0.001). The significant interaction (p=0.025) between bedrest and intervention was explained by greater baseline orthostatic tolerance time in the ctr. AG Data was pooled analysis. The reduction in stroke volume (ctr, pre: 93±19 ml, HDTBR: 69±13 ml, AG, pre: 88±20 ml, HDTBR: 67±17 ml) and plasma volume was similar (ctr, pre: 4155±1085 ml, HDTBR: 3855±1087 ml, AG, pre: 4114±1250 ml, HDTBR: 3674± 1313 ml). Catechols and aldosterone did not change significantly during bedrest. The increase in renine was similar between groups (ctr pre: 18±12 mE/L, HDTBR: 21±8 mE/L, AG pre: 21±10 mE/L, HDTBR: 31±12 mE/L). Conclusions: 30 min daily AG didn’t prevent a reduction in orthostatic tolerance following 60d HDTBR. Whether numerically smaller reductions in orthostatic tolerance in the AG groups indicate efficacy or result from baseline differences can’t be ascertained. A stronger AG stimulus or combination with other countermeasures might be required to maintain orthostatic tolerance and to attenuate the volume reduction.