scholarly journals A Novel Cardiac Force Index Measured by Digital Devices and Applied to the G Tolerance Test among Military Aircrews: An Observational Study (Preprint)

JMIR Cardio ◽  
10.2196/28853 ◽  
2021 ◽  
Author(s):  
Kwo-Tsao Chiang ◽  
Min-Yu Tu ◽  
You-Jin Lin ◽  
Yi-Hsiang Hsin ◽  
Yu-Lung Chiu ◽  
...  
2001 ◽  
Vol 281 (4) ◽  
pp. E766-E771 ◽  
Author(s):  
Adam J. Rose ◽  
Kirsten Howlett ◽  
Douglas S. King ◽  
Mark Hargreaves

Several studies have demonstrated that oral glucose tolerance is impaired in the immediate postexercise period. A double-tracer technique was used to examine glucose kinetics during a 2-h oral glucose (75 g) tolerance test (OGTT) 30 min after exercise (Ex, 55 min at 71 ± 2% of peak O2 uptake) and 24 h after exercise (Rest) in endurance-trained men. The area under the plasma glucose curve was 71% greater in Ex than in Rest ( P = 0.01). The higher glucose response occurred even though whole body rate of glucose disappearance was 24% higher after exercise ( P = 0.04, main effect). Whole body rate of glucose appearance was 25% higher after exercise ( P = 0.03, main effect). There were no differences in total (2 h) endogenous glucose appearance (Ra e) or the magnitude of suppression of Ra e, although Ra e was higher from 15 to 30 min during the OGTT in Ex. However, the cumulative appearance of oral glucose was 30% higher in Ex ( P = 0.03, main effect). There were no differences in glucose clearance rate or plasma insulin responses between the two conditions. These results suggest that adaptations in splanchnic tissues by prior exercise facilitate greater glucose output from the splanchnic region after glucose ingestion, resulting in a greater glycemic response and, consequently, a greater rate of whole body glucose uptake.


2021 ◽  
Author(s):  
Kwo-Tsao Chiang ◽  
Min-Yu Tu ◽  
You-Jin Lin ◽  
Yi-Hsiang Hsin ◽  
Yu-Lung Chiu ◽  
...  

BACKGROUND Military aircrew are occupationally exposed to a high-G environment. G force causes blood to flow to the lower body region and challenges their cardiac function and anti-G straining maneuver effectiveness. A tolerance test is necessary for every military aircrew member before undergoing flight training. A novel cardiac force index (CFI) has been developed and used to assess long-distance running by mobile health (mHealth) technology. There is still no study to monitor the CFI by wearable devices during the G tolerance test. OBJECTIVE We added the cardiac function parameter CFI to the G tolerance test and elucidated the relationship between cardiac function and G tolerance among military aircrew. METHODS A noninvasive device, BioHarness 3.0, was used to measure heart rate (HR) and activity while resting and walking on the ground. The mathematical formula for cardiac function calculation is CFI = weight × activity/HR. The cardiac force ratio (CFR) is calculated by walking CFI (WCFI)/resting CFI (RCFI). G tolerance includes relaxed G tolerance (RGT) and straining G tolerance (SGT) tested by a human centrifuge under the gradual-onset-rate profile. RESULTS In total, 92 male participants voluntarily completed this study. The average values of RCFI, WCFI, and CFR were 0.02 [SD 0.04], 0.15 [SD 0.04], and 10.77 [SD 4.11], respectively. The mean RGT and SGT were 5.1G [SD 0.9] and 7.8G [SD 1.1], respectively, in the centrifuge. The percentages of participants with RGT greater than 5G or SGT greater than 8G were equally noted as 54.3%. Each 100-unit increase in WCFI increased RGT by 0.14G [SE 0.02, 95% CI 0.09 to 0.19] and by 0.17G [SE 0.03, 95% CI 0.11 to 0.22], corresponding to SGT. In addition, there was an increased chance of RGT values higher than 5G and SGT values higher than 8G according to the increase in WCFI. CONCLUSIONS Our results suggested that WCFI is positively correlated with G tolerance in the centrifuge and has the potential to be used for military aircrew selection.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angelo Dante ◽  
Elona Gaxhja ◽  
Vittorio Masotta ◽  
Carmen La Cerra ◽  
Valeria Caponnetto ◽  
...  

AbstractGradual replacement of the mercury thermometers with alternative devices is ongoing around the world in a bid to protect human health and the environment from the adverse effects of mercury. However, to reduce the risks of misdiagnosis, unnecessary treatments, and omission of care in pediatric populations, more evidence on the reliability of alternative thermometers is needed. The aim of this comparative observational study was to detect any differences in temperature measurements between the use of the axillary mercury thermometer and the alternative techniques. Temperature values in degree Celsius (°C) were measured in a group of Albanian children aged up to 14 years using mercury and digital axillary thermometers, as well as forehead and tympanic infrared thermometers. The digital axillary device, compared with the mercury one, showed no clinically significant difference in the mean values (− 0.04 ± 0.29 °C) and the narrowest 95% level of agreement (+ 0.53 °C to − 0.62 °C) in the paired comparisons. For cut-off point of 37.5 °C, the digital axillary thermometer showed the highest levels of sensitivity (72.5%) and specificity (99.1%) in detecting fever. This study indicates that the digital axillary thermometer may be the better option since it adequately balances accuracy, safety, and children’s comfort.


2020 ◽  
Author(s):  
Angelo Dante ◽  
Elona Gaxhja ◽  
Vittorio Masotta ◽  
Carmen La Cerra ◽  
Valeria Caponnetto ◽  
...  

Abstract A gradual replacement of the mercury thermometers with alternative devices is ongoing around the world as effect of the global strategies to reduce mercury pollution. However, to reduce the risks of misdiagnosis, unnecessary treatments, and omission of care in the pediatric population, more evidence on the reliability and validity of alternative thermometers are needed. The aim of this comparative observational study was to detect any differences in temperature measurements between the gold-standard axillary mercury thermometer (AXLMER) and the alternative devices. Temperature values in Celsius (°C) were simultaneously measured in a group of Albanian children aged up to 14 years using both (AXLMER) and digital axillary thermometers (AXLDGT), as well as forehead and tympanic infra-red thermometers. The AXLDGT device, compared with the AXLMER, showed no clinically significant difference in the mean values (-0.04 ± 0.29 °C) and the narrowest 95% Level of Agreement (+0.53 °C to -0.62 °C) in the paired comparisons. For cut-off points of 37.0 °C and 37.5 °C, the AXLDGT showed the highest levels of sensitivity (67.4% and 72.5%) and specificity (95.3% and 99.1%) in detecting fever. This study indicates that the AXLDGT thermometer may prove the better option since it adequately balances accuracy, safety and children’s comfort.


Author(s):  
Kwo-Tsao Chiang ◽  
Min-Yu Tu ◽  
You-Jin Lin ◽  
Yi-Hsiang Hsin ◽  
Yu-Lung Chiu ◽  
...  

Military aircrew are occupationally exposed to a high-G environment. A tolerance test and surveillance is necessary for military aircrew before flight training. A cardiac force index (CFI) has been developed to assess long-distance running by health technology. We added the parameter CFI to the G tolerance test and elucidated the relationship between the CFI and G tolerance. A noninvasive device, BioHarness 3.0, was used to measure heart rate (HR) and activity while resting and walking on the ground. The formula for calculating cardiac function was CFI = weight × activity/HR. Cardiac force ratio (CFR) was calculated by walking CFI (WCFI)/resting CFI (RCFI). G tolerance included relaxed G tolerance (RGT) and straining G tolerance (SGT) tested in the centrifuge. Among 92 male participants, the average of RCFI, WCFI, and CFR were 0.02 ± 0.04, 0.15 ± 0.04, and 10.77 ± 4.11, respectively. Each 100-unit increase in the WCFI increased the RGT by 0.14 G and the SGT by 0.17 G. There was an increased chance of RGT values higher than 5 G and SGT values higher than 8 G according to the WCFI increase. Results suggested that WCFI is positively correlated with G tolerance and has the potential for G tolerance surveillance and programs of G tolerance improvement among male military aircrew.


Sign in / Sign up

Export Citation Format

Share Document