Abstract
A technique that allowsin vivo measurements of the specific impedance of brain structures is analysed and implemented. This technique uses the 4-electrode method. The system includes an optically isolated current source and an interchangeable electrode module. Tests on the measuring system, including the electrodes and calibration procedures, are presented. Experiments in media of known resistivity and in cat brains define the present limits of the spatial resolution.
Sommaire
L'article décrit une technique permettant de mesurerin vivo l'impédance spécifique des structures du cerveau, ainsi que sa mise en oeuvre. Cette technique adopte la méthode à quatre électrodes. Le système comprend une source de courant optiquement isolée, et une unité interchangeable à électrodes. L'article présente des essais sur le système de mesure, y compris les électrodes et les procédures d'étalonnage. Les expériences dans des milieux de résistivité connue et dans des cerveaux de chats définissent les limites actuelles de la résolution spatiale.
Zusammenfassung
Eine Methode, welche diein-vivo-Messungen der spezifischen Impedanz von Gehirnstrukturen zuläßt, wird analysiert und implementiert. Das Verfahren basiert auf der 4-Elektroden-Methode. Das System beeinhaltet eine optische isolierte Stromquelle und ein auswerchselbares Elektrodenmodul. Tests am Meßsystem einschließlich Elektroden- und Eichverfahren werden präsentiert. Experimente an Medien von bekanntem spezifischem elektrischem Widerstand sowie an Katzengehirnen definieren die gegenwärtigen Grenzen der räumlichen Auflösung.
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Robillard, P.N., Poussart, Y. Specific-impedance measurements of brain tissues. Med. Biol. Eng. Comput. 15, 438–445 (1977). https://doi.org/10.1007/BF02457999
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DOI: https://doi.org/10.1007/BF02457999