scholarly journals Electrochemical Approach to Measure Physiological Fluid Flow Rates

2021 ◽  
Vol 9 ◽  
Author(s):  
Srivats Sarathy ◽  
Marco A. Nino ◽  
Abduldattar H. Alsaedi ◽  
Srinivasan Rajagopal ◽  
Syed Mubeen ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Current Amplitude ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Flow Rates ◽  
Ac Voltammetry ◽  
Electrochemical Approach ◽  
Physiological Fluid

In vivo measurement of the flow rate of physiological fluids such as the blood flow rate in the heart is vital in critically ill patients and for those undergoing surgical procedures. The reliability of these measurements is therefore quite crucial. However, current methods in practice for measuring flow rates of physiological fluids suffer from poor repeatability and reliability. Here, we assessed the feasibility of a flow rate measurement method that leverages time transient electrochemical behavior of a tracer that is injected directly into a medium (the electrochemical signal caused due to the tracer injectate will be diluted by the continued flow of the medium and the time response of the current—the electrodilution curve—will depend on the flow rate of the medium). In an experimental flow loop apparatus equipped with an electrochemical cell, we used the AC voltammetry technique and tested the feasibility of electrodilution-based measurement of the flow rate using two mediums—pure water and anticoagulated blood—with 0.9 wt% saline as the injectate. The electrodilution curve was quantified using three metrics—change in current amplitude, total time, and change in the total charge for a range of AC voltammetry settings (peak voltages and frequencies). All three metrics showed an inverse relationship with the flow rate of water and blood, with the strongest negative correlation obtained for change in current amplitude. The findings are a proof of concept for the electrodilution method of the flow rate measurement and offer the potential for physiological fluid flow rate measurement in vivo.

Transit Time Correlation—A Survey on Its Applications to Measuring Transport Phenomena

1974 ◽  
Vol 96 (4) ◽  
pp. 414-420 ◽  
Author(s):  
F. Mesch ◽  
R. Fritsche ◽  
H. Kipphan
Keyword(s):  
Dynamical Systems ◽  
Transit Time ◽  
Flow Rate ◽  
Time Correlation ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Flow Rates ◽  
Identification Methods ◽  
Special Cases ◽  
Different Types

A survey is given on different types of correlation methods and their application to measuring velocity of moving surfaces, flow rates, and to ranging. The different methods are unified by regarding them as special cases of classical identification methods for dynamical systems. Special difficulties occurring in flow rate measurement are discussed in some detail, and some problems yet to be solved are indicated.

Indirect measurement of the flow rate based upon a solution of an inverse coefficient problem

2018 ◽  
Vol 28 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Kazimierz Rup ◽  
Lukasz Malinowski ◽  
Piotr Sarna
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Indirect Method ◽  
Measuring Method ◽  
High Accuracy ◽  
Fluid Flow Rate ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Flow Meter ◽  
Content Type

Purpose The purpose of this paper is to extend the possibilities of using the earlier developed indirect method of fluid flow rate measurement in circular pipes to the square-section channels with elbows installed. Design/methodology/approach The idea of the method is based on selecting such a value of the Reynolds number assumed as a coefficient in fluid flow equations, which fulfills with set accuracy the condition of equality between the measured and computed pressure difference at the end points of the secant of the elbow arch. The numerical calculus takes into consideration the exact geometry of the flow space and the measured temperature of the fluid, on the basis of which its thermo–physical properties are determined. To implement the proposed method in practice, a special test stand was built. The numerical computations were carried out using the software package FLUENT. Findings The results of calculations were compared with corresponding results of measurements achieved on the stand, as well as those found in the literature. The comparative analysis of the obtained numerical and experimental results shows a high grade of consistence. Practical implications The discussed elbow flow meter, implementing the extended indirect measuring method, can be applied to determine the flow rate of gases, as well as liquids and suspensions. Originality/value The indirect method used to measure the volumetric flow rate of the fluid is characterized by high accuracy and repeatability. The high accuracy is possible because of a very realistic mathematical model of the complex flow in the curved duct. The indirect method eliminates the necessity of frequent calibration of the flow meter. The discussed extended indirect measuring method can be applied to determine the flow rate of gases as well as liquids and suspensions. The fluid flow rate measurement based on the method considered in this paper can be particularly useful in newly designed as well as already operated ducts.

CVT Fluid Flow Rate Measurement in CVT Lubricating Systems

2005 ◽  
Author(s):  
Michiyasu Moritsugu ◽  
Tadayoshi Nakase ◽  
Makoto Okada ◽  
Yasuyuki Haseo ◽  
Kouji Morioka ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Fluid Flow Rate ◽  
Rate Measurement ◽  
Flow Rate Measurement

A Flexible Hair-Like Laser Induced Graphitic Sensor for Low Flow Rate Sensing Applications

2020 ◽  
Author(s):  
Behrokh Abbasnejad ◽  
David McGloin ◽  
Lee Clemon
Keyword(s):  
Flow Rate ◽  
Small Diameter ◽  
Cost Effective ◽  
Low Flow ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Resistance Change ◽  
Flow Rates ◽  
Sensing Applications ◽  
Low Flow Rate

Abstract Direct low flow sensing is of interest to many applications in medical and biochemical industries. Low flow rate measurement is still challenging, and conventional flow sensors such as hot films, hot wires and Pitot probes are not capable of measuring very low flow rates accurately. In some applications that require flow measurement in a small diameter tubing (e.g. intravenous (IV) infusion), using such sensors also becomes mechanically impractical. Herein, a flexible laser-induced graphitic (LIG) piezoresistive flow sensor has been fabricated in a cost-effective single processing step. The capability of the LIG sensor in very low flow rate measurement has been investigated by embedding the sensor within an intravenous (IV) line. The embedded LIG hair-like sensor was tested at ambient temperature within the IV line at flow rates ranging from 0 m/s to 0.3 m/s (IV infusion free-flow rate). The LIG hair-like sensor presented in this study detects live flow rates of IV infusions with a threshold detection limit as low as 0.02 m/s. Moreover, the deformation of the LIG hair-like sensor that lead to resistance change in response to various flow rates is simulated using COMSOL Multiphysics.

Sign in / Sign up

Export Citation Format

Share Document