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.

scholarly journals Ultra-low flow rate measurement techniques

2021 ◽  
Vol 18 ◽  
pp. 100279
Author(s):  
Emmelyn Graham ◽  
Kerstin Thiemann ◽  
Sabrina Kartmann ◽  
Elsa Batista ◽  
Hugo Bissig ◽  
...  
Keyword(s):  
Flow Rate ◽  
Measurement Techniques ◽  
Low Flow ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Low Flow Rate

A self-bended piezoresistive microcantilever flow sensor for low flow rate measurement

2010 ◽  
Vol 158 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Qi Zhang ◽  
Wenzhou Ruan ◽  
Han Wang ◽  
Youzheng Zhou ◽  
Zheyao Wang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Flow Sensor ◽  
Low Flow ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Low Flow Rate

Drop interval flowmeter for low flow rate measurement

1989 ◽  
Vol 38 (3) ◽  
pp. 309-313
Author(s):  
Robert L. Hester ◽  
B.J. Barber
Keyword(s):  
Flow Rate ◽  
Low Flow ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Low Flow Rate

Rheological Effects of Blood in a Nonplanar Distal End-to-Side Anastomosis

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Qian-Qian Wang ◽  
Bao-Hong Ping ◽  
Qing-Bo Xu ◽  
Wen Wang
Keyword(s):  
Flow Rate ◽  
Stokes Equations ◽  
Bypass Graft ◽  
High Flow ◽  
Secondary Flows ◽  
Newtonian Fluids ◽  
Low Flow ◽  
Flow Rates ◽  
Flow Recirculation ◽  
Low Flow Rate

This study investigates rheological effects of blood on steady flows in a nonplanar distal end-to-side anastomosis. The shear-thinning behavior of blood is depicted by a Carreau–Yasuda model and a modified power-law model. To explore effects of nonplanarity in vessel geometry, a curved bypass graft is considered that connects to the host artery with a 90deg out-of-plane curvature. Navier–Stokes equations are solved using a finite volume method. Velocity and wall shear stress (WSS) are compared between Newtonian and non-Newtonian fluids at different flow rates. At low flow rate, difference in axial velocity profiles between Newtonian and non-Newtonian fluids is significant and secondary flows are weaker for non-Newtonian fluids. At high flow rate, non-Newtonian fluids have bigger peak WSS and WSS gradient. The size of the flow recirculation zone near the toe is smaller for non-Newtonian fluids and the difference is significant at low flow rate. The nonplanar bypass graft introduces helical flow in the host vessel. Results from the study reveal that near the bed, heel, and toe of the anastomotic junction where intimal hyperplasia occurs preferentially, WSS gradients are all very big. At high flow rates, WSS gradients are elevated by the non-Newtonian effect of blood but they are reduced at low flow rates. At these locations, blood rheology not only affects the WSS and its gradient but also secondary flow patterns and the size of flow recirculation near the toe. This study reemphasizes that the rheological property of blood is a key factor in studying hemodynamic effects on vascular diseases.

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.

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.

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