Physical-Weight-Based Measurement Methodology Suppressing Noise or Reducing Test Time for High-Resolution Low-Speed ADCs

Continuous hemodynamic monitoring is important for long-term cardiovascular healthcare, especially in hypertension. The impedance plethysmography (IPG) based carotid pulse sensing is a non-invasive diagnosis technique for measuring pulse signals and further evaluating the arterial conditions of the patient such as continuous blood pressure (BP) monitoring. To reach the high-resolution IPG-based carotid pulse detection for cardiovascular applications, this study provides an optimized measurement parameter in response to obvious pulsation from the carotid artery. The influence of the frequency of excitation current, electrode cross-sectional area, electrode arrangements, and physiological site of carotid arteries on IPG measurement resolution was thoroughly investigated for optimized parameters. In this study, the IPG system was implemented and installed on the subject’s neck above the carotid artery to evaluate the measurement parameters. The measurement results within 6 subjects obtained the arterial impedance variation of 2137 mΩ using the optimized measurement conditions, including excitation frequency of 50 kHz, a smaller area of 2 cm2, electrode spacing of 4 cm and 1.7 cm for excitation and sensing functions, and location on the left side of the neck. The significance of this study demonstrates an optimized measurement methodology of IPG-based carotid pulse sensing that greatly improves the measurement quality in cardiovascular monitoring.

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Design of an Economical Counter Rotating Fan: Comparison of the Calculated and Measured Steady and Unsteady Results

Volume 1: Aircraft Engine; Ceramics; Coal, Biomass and Alternative Fuels; Controls, Diagnostics and Instrumentation ◽

10.1115/gt2012-69587 ◽

2012 ◽

Cited By ~ 6

Author(s):

Timea Lengyel-Kampmann ◽

Andreas Bischoff ◽

Robert Meyer ◽

Eberhard Nicke

Keyword(s):

High Resolution ◽

Total Pressure ◽

High Efficiency ◽

Optimization Method ◽

Test Facility ◽

Hot Wire ◽

Stall Margin ◽

Low Speed ◽

Total Temperature ◽

German Aerospace

Within the framework of the EU funded Project VITAL, SNECMA (Group Safran), as the work package leader, developed a counter rotating low-speed fan-concept for a high bypass ratio engine. The detailed aerodynamic and mechanical optimization of one blading version (CRTF2.b) was carried out at the German Aerospace Center (DLR), by applying one of the newest design methods featuring a multi-objective automatic optimization method based on an Evolutionary Algorithm [1]. The final design goals were high efficiency, a sufficient stall margin and adequate acoustic performances for the given cycle parameters. The fan stage developed was tested in an anechoic test facility at CIAM in Moscow. The test routine included the measurement of the performance map based on total pressure and total temperature measurements at the inlet and the outlet of the test rig and acoustic measurement as well. The unsteady flow field of the low speed Contra-Rotating Turbo Fan has been measured with four hot-wire probes at different axial positions. In the evaluation the measured data are compared with high resolution CFD results. Special emphasis was given to the comparison of the radial distribution of total pressure and total temperature in the bypass channel, the comparison of the measured and the calculated fan maps and to the comparison of the hot-wire measurements with high resolution, unsteady CFD results. The tests and the URANS-results confirmed the design goals.

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