Relationship Between the Conductivity of Human Blood and Blood Counts

Abstract

Achieving a better characterization of human blood conductivity is of high relevance for medical applications. In this study we measured the complex impedance of N = 10 human whole blood samples (from N = 10 oncology patients) at room temperature (T = 22.6 ± 0.8 • C) and at body temperature (T = 36.6 ± 0.4 • C). The complex impedance was measured using the measurement setup consisting of a custom made four-electrode probe and a commercially available galvanostat. The measured complex impedance data were used to calculate the conductivity of whole blood over the 631 Hz-100 kHz frequency range. The calculated conductivity data is presented and was compared with the literature data. The data from our study is in good agreement with the data available in the literature. Additionally, full blood counts were provided for N = 8 samples and Pearson correlation coefficient was calculated between the conductivity and blood counts at different frequencies. The three blood count parameters with the highest correlation coefficient are haematocrit (Hct), haemoglobin (Hgb) and red cell count (RBC). The correlation coefficient was shown to decrease as the frequency increases and was the highest at f = 631 Hz, which is the lowest reported frequency. To our knowledge this is the first study to measure low-frequency (i.e. below 1 MHz) conductivity of whole human blood at body temperature using the four-electrode technique. The results of this study represent an important contribution to the literature, which is currently limited in this area and will help further medical device design.

Probe Contact Force Monitoring during Conductivity Measurements of the Left Atrial Appendage to Support the Design of Novel Diagnostic and Therapeutic Procedures

“…The conductivity is acquired from the frequency-dependent complex impedance using the methods described in [ 6 , 26 , 27 ]. The conductivity is then computed from the measured frequency-dependent complex impedance and the probe cell constant using Equation (1) [ 6 , 26 ].…”

“…The conductivity is acquired from the frequency-dependent complex impedance using the methods described in [ 6 , 26 , 27 ]. The conductivity is then computed from the measured frequency-dependent complex impedance and the probe cell constant using Equation (1) [ 6 , 26 ]. where σ [Sm −1 ] is the electrical conductivity of a reference liquid, G [S] is the measured conductance (derived from the complex impedance Z ), and k [m −1 ] is the cell constant.…”

“…The electrical properties of biological tissues have been of interest since 1894 and have been widely studied in the literature [ 1 , 2 ]. The electrical properties of biological tissue have been studied for several human organs [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ] and have been used to develop many therapeutic and diagnostic technologies [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

“…The electrical properties (in terms of conductivity, σ ) are acquired using a probe in contact with the tissue to measure the ratio of electrical charge flow in response to a difference in electrical potential. The measuring methods are reviewed in detail in [ 6 , 23 , 26 , 27 , 28 ]. The contact between the probe and tissue is fixed throughout the experiment.…”

Design of a Tetrapolar Probe for Electrical Characterization of the Left Atrial Appendage From 0.1 Hz to 100 kHz

“…The electrical properties, specifically conductivity of the LAA are used for treatment planning of IRE [14]. The electrical conductivity of tissues is a common input for biomedical device design and treatment planning, it can be seen in diverse applications including electrical impedance tomography [10], [15], human blood count monitoring [16], neuron-stimulation systems [2], [12], [13], devices for obstetric applications which compare the electrical impedance of the gravid and non-gravid uterus and cervix [14], [15], and in applications related to oncology comparing normal to cancerous tissues [3], [4], [9], [16]- [19].…”