PVP2006-ICPVT11-93950 CALCULATION OF STATIC AND DYNAMIC CHARACTERISTICS OF MULTI WOUNDED RADIAL FOIL BEARING BASED ON LEAKAGE FLOW INDUCED VIBRATION THEORY

ABSTRACT Dynamic pressure type foil bearings are expected to serve as shaft bearings for Micro Gas Turbines (MGT). In this study, in order to establish design guidelines of radial foil bearings, dynamical modeling of multi wounded foil bearing was carried out employing leakage flow induced vibration theory. Taking frictional forces due to attached part of the foil and the protrusion, etc. into consideration, static and dynamic characteristics were analyzed to examine the performance and the stability of radial foil bearings

Association between preoperative toe perfusion index and maternal core temperature decrease during cesarean delivery under spinal anesthesia: a prospective cohort study

Background: The main mechanism of body temperature decrease during cesarean delivery under spinal anesthesia is core-to-peripheral redistribution of body heat, attributable to vasodilation. Perfusion index (PI) obtained with a pulse oximeter helps to assess peripheral perfusion dynamics by detecting the change in peripheral vascular tone. This study aimed to examine whether preoperative toe PI could predict the decrease in core temperature induced by spinal anesthesia during cesarean delivery.Methods: Parturients undergoing scheduled cesarean delivery under combined spinal-epidural anesthesia from September 2019 to March 2020 were enrolled in this single-center prospective cohort study. All parturients received 0.5% hyperbaric bupivacaine (10 mg) with fentanyl (15 μg) intrathecally. A pulse oximeter probe was placed on the left second toe for continuous PI measurement. The 3 M™ Bair Hugger™ Temperature Monitoring System placed over the right temporal region was used to record core temperature over time. We evaluated the association between the maximum core temperature decrease, which is the primary outcome, and the preoperative toe PI at operating room (OR) admission using a segmented regression model (SRM) and a generalized additive model (GAM). The maximum core temperature decrease was defined as the difference between core temperature at OR admission and minimum intraoperative core temperature.Results: Forty-eight patients were evaluated. In the SRM, the slope for the association between the maximum core temperature decrease and the preoperative toe PI changed from 0.031 to 0.124 after PI = 2.4%. Likewise, with the GAM, there was a small core temperature decrease when preoperative toe PI was greater than 2.0 to 3.0%.Conclusions: Low preoperative toe PI was associated with maternal core temperature decrease during cesarean delivery under spinal anesthesia. Preoperative toe PI is a simple, non-invasive, and effective tool for the early prediction of perioperative core temperature decrease during cesarean delivery.Trial registration: UMIN Clinical Trials Registry (registry number: UMIN000037965)