Measurement of Electrical Conductivity of Human Blood at Frequencies Below 100 kHz with Four-electrode Probe Method

Ištuk, Niko; Gioia, Alessandra La; Benchakroun, Hamza; O’Loughlin, Declan; Lowery, Aoife; Porter, Emily; O’Halloran, Martin

doi:10.23919/ursigass51995.2021.9560424

Cited by 4 publications

(2 citation statements)

References 9 publications

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“…The gel conductivity was measured using a conductivity meter with the electrodes immersed in the solution before and after setting. The conductivity level was chosen as it falls within the wide range of reported conductivities of human blood [13,14].…”

Section: Discussionmentioning

confidence: 99%

Electric-Field-Based Guidance for Percutaneous Catheter Vessel Crossing

Diallo¹,

Eder²,

Brasier³

et al. 2022

Sensors

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Percutaneous procedures to divert blood flow from one blood vessel to another can be performed with intravascular catheters but demand a method to align a crossing needle from one vessel to another. Fluoroscopic imaging alone is not adequate, and it is preferable to have a sensor on one catheter that detects the correct alignment of an incoming needle. This can be implemented by generating dipole electric fields from the crossing catheter which are detected by a receiving catheter in the target vessel and, thus, can calculate and display the degree of alignment, permitting the operator to rotate the crossing catheter to guarantee alignment when deploying a crossing needle. Catheters were built using this concept and evaluated in vitro. The results show that accurate alignment is achieved, and a successful crossing can be made. The concept is being further developed for further clinical evaluation.

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Section: Discussionmentioning

confidence: 99%

Electric-Field-Based Guidance for Percutaneous Catheter Vessel Crossing

Diallo¹,

Eder²,

Brasier³

et al. 2022

Sensors

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“…Another research found that a simple and inexpensive fourelectrode probe can be utilized for determining the electrical conductivity of blood for counting red blood cells at lower frequencies (below 100 KHz and 1 MHz). The method is a useful tool based on measuring the conductivity of human blood at low frequencies and at body temperature [18,19]. Recently, a chemiluminescence biosensor employing a CLIA-based system effectively quantified the human blood hematocrit percentage from 0% to 65% [20].…”

Section: Introductionmentioning

confidence: 99%

The cavity perturbation method for evaluating hematocrit via dielectric properties

Kamel,

Alawajji,

Kannarpady

2023

Biomed. Phys. Eng. Express

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The physical parameters of human blood (complex permittivity and conductivity) at microwave frequencies have been investigated to assess the hematocrit (HCT). The cavity perturbation method based on a rectangular cavity operated in TE101 mode at frequency 4.212GHz has been utilized to measure the permittivity of blood with different hematocrit % at a range of temperatures. According to the results, the dielectric constant, loss factor, and conductivity appeared to be influenced by HCT level. Though the dielectric constant is the only parameter that shows clear linear regression decreasing behavior with a correlation value around (R2=0.93). For thirty healthy donors the dielectric constant decreases from (65.61±1.4 to 44.64±4.0) and from (65.3±1.2 to 48.3±1.88) for men and women, respectively, with increasing hematocrit percentage from 20% HCT up to 95% HCT. The temperature dependence of the dielectric constant is also examined in the temperature range 27-50oC and the results display a slight decrease in dielectric constant with elevation temperature. The temperature-dependence dielectric constant of water and blood samples were fitted to an empirical polynomial with temperature. A comparison of estimated HCT using the cavity technique based on dielectric properties shows a very good agreement with commercially standard HCT measurement methods. Finally, the cavity technique can be applied to measure the hematocrit up to high values based on the dielectric constant with high precision, simplicity, and low cost compared with traditional techniques.

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