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The voltage-current characteristic of the human skin
Dissertation (M Eng (Bio-Engineering))--University of Pretoria, 2006.
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| Format: | Thesis |
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University of Pretoria
2013
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| _version_ | 1867613717456224256 |
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| access_status_str | Open Access |
| author2 | Cilliers, P.J. |
| author_browse | Cilliers, P.J. |
| author_facet | Cilliers, P.J. |
| collection | Thesis |
| dc_rights_str_mv | © 2003, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (M Eng (Bio-Engineering))--University of Pretoria, 2006. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/28072 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:40:35.305Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/28072 The voltage-current characteristic of the human skin Cilliers, P.J. upetd@up.ac.za Lochner, George Philip Biomedical engineering Skin physiology Electricity in medicine UCTD Dissertation (M Eng (Bio-Engineering))--University of Pretoria, 2006. The objective of this dissertation is to provide insight into the mechanisms that are responsible for the nonlinearities and asymmetries of the voltage current characteristic of the human skin. Furthermore to provide an explanation for the partially reversible breakdown of the electrical resistance of the skin that results in a rapid decrease of the skin resistance and occurs when the skin is stimulated with a dry electrode. The skin resistance and impedance was investigated with low frequency constant voltage pulses and with sinusoidal stimulation over a range of amplitudes (10 - 20 V) and frequencies (3 - 30 Hz), using a dry 79 mm2 Ag/AgCI electrode. Evidence is presented that electroporation of the lipid bilayer membranes occurs in the dry skin over in the voltage range 10-20 V, a wider range than previously thought; it is further shown that experimental results are predicted by electroporation theory, if it is assumed that a small percentage of the total surface area of the dry skin consists of 15 lipid bilayers in series, rather than the generally accepted estimate of 70-100 layers. By modeling the dry skin as 15 lipid bilayers in series undergoing electroporation, the non-linearity of voltage-current characteristic of the skin is accurately predicted. Evidence is presented in support of a new hypothesis that the asymmetry of the skin's voltage-current characteristic can be attributed to electro-osmosis occurring within the lipid bilayers of the stratum corneum. It is further suggested that the existing mathematical description of electro-osmosis would not accurately describe this situation and equations were introduced to model the effect of electro-osmosis on the voltage-current characteristic of the skin. An electrical model of the skin is presented based on the hypothesis that the VOltage-current characteristic of the skin is due to the combined effect of electroporation and electro-osmosis on the lipid bilayers in the stratum corneum. In addition the model accounts for the effect of trans epidermal water loss. Civil Engineering unrestricted 2013-09-07T12:49:33Z 2005-09-22 2013-09-07T12:49:33Z 2003-09-01 2006-09-22 2005-09-21 Dissertation Lochner, GP 2003, The voltage-current characteristic of the human skin, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/28072 > H199/ag http://hdl.handle.net/2263/28072 http://upetd.up.ac.za/thesis/available/etd-09212005-093111/ © 2003, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Biomedical engineering Skin physiology Electricity in medicine UCTD The voltage-current characteristic of the human skin |
| title | The voltage-current characteristic of the human skin |
| title_full | The voltage-current characteristic of the human skin |
| title_fullStr | The voltage-current characteristic of the human skin |
| title_full_unstemmed | The voltage-current characteristic of the human skin |
| title_short | The voltage-current characteristic of the human skin |
| title_sort | voltage current characteristic of the human skin |
| topic | Biomedical engineering Skin physiology Electricity in medicine UCTD |
| url | http://hdl.handle.net/2263/28072 http://upetd.up.ac.za/thesis/available/etd-09212005-093111/ |