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Marking 100 years since Rudolf Höber’s discovery of the insulating envelope surrounding cells and of the β-dispersion exhibited by tissue Cover

Marking 100 years since Rudolf Höber’s discovery of the insulating envelope surrounding cells and of the β-dispersion exhibited by tissue

Journal of Electrical Bioimpedance
Volume 3 (2012): Issue 1 (January 2012)
By: Ronald Pethig and  Ilka Schmueser  
Open Access
|Nov 2012

Figures & Tables

Figure 1

A schematic of the β-dispersion exhibited by fresh tissues and compacted viable cells (derived from Schwan [4]). As the frequency is increased from ~1 kHz to 100 MHz, this dispersion is characterised by about a five-fold increase of conductivity, and around three orders of magnitude decrease of permittivity ε.
A schematic of the β-dispersion exhibited by fresh tissues and compacted viable cells (derived from Schwan [4]). As the frequency is increased from ~1 kHz to 100 MHz, this dispersion is characterised by about a five-fold increase of conductivity, and around three orders of magnitude decrease of permittivity ε.

Figure 2

Based on Höber’s original drawing [1] his signal generator consisted of an induction coil connected to a spark gap. The frequency of the induced transient oscillating current in the external circuit was determined by the capacitance C of a glass plate and the inductance of a coil wound onto a gas lamp. The conductivity of a trough (trog) of vials to mimic a cell sample, or of a sample of compacted red blood cells, was determined by comparing the damping of the oscillating current due to ion conduction against that of a series of NaCl solutions. Different forms of detector were tested to optimise the determination of the damping effect.
Based on Höber’s original drawing [1] his signal generator consisted of an induction coil connected to a spark gap. The frequency of the induced transient oscillating current in the external circuit was determined by the capacitance C of a glass plate and the inductance of a coil wound onto a gas lamp. The conductivity of a trough (trog) of vials to mimic a cell sample, or of a sample of compacted red blood cells, was determined by comparing the damping of the oscillating current due to ion conduction against that of a series of NaCl solutions. Different forms of detector were tested to optimise the determination of the damping effect.

Figure 3

Equivalent circuits proposed for: (a) tissues and compacted red blood cells by Philippson [20]. R and r are attributed to the cytoplasm and membrane resistance, respectively, and C to the membrane capacitance; (b) red blood cell suspensions proposed by Fricke & Morse [5], in which R0 is the resistance to current flow around the cell, and Ri is the cytoplasm resistance; (c) the squid giant axon by Cole & Baker to account for their discovery of the inductive reactance [26]. The values for R, C and L were determined as 1 kΩ cm2, 1 μF/cm2 and 0.2 H cm2, respectively.
Equivalent circuits proposed for: (a) tissues and compacted red blood cells by Philippson [20]. R and r are attributed to the cytoplasm and membrane resistance, respectively, and C to the membrane capacitance; (b) red blood cell suspensions proposed by Fricke & Morse [5], in which R0 is the resistance to current flow around the cell, and Ri is the cytoplasm resistance; (c) the squid giant axon by Cole & Baker to account for their discovery of the inductive reactance [26]. The values for R, C and L were determined as 1 kΩ cm2, 1 μF/cm2 and 0.2 H cm2, respectively.
Rudolf Höber, ca. 1950. (Reproduced with permission of the American Philosophical Society.)
Rudolf Höber, ca. 1950. (Reproduced with permission of the American Philosophical Society.)
DOI: https://doi.org/10.5617/jeb.401 | Journal eISSN: 1891-5469
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Language: English
Page range: 74 - 79
Submitted on: Sep 7, 2012
Published on: Nov 23, 2012
Published by: University of Oslo
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year
Keywords:
Dielectric beta-dispersion,
Cells,
Erythrocytes, Membrane capacitance,
Membrane resistance,
Muscle cells,
Tissue impedance
Related subjects:
Engineering,
Bioengineering and biomedical engineering,
Biomedical electronics,
Life sciences,
Biophysics,
Medicine,
Biomedical engineering,
Physics,
Spectroscopy and metrology

© 2012 Ronald Pethig, Ilka Schmueser, published by University of Oslo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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