A Batteryless Sensor ASIC for Implantable Bio-Impedance Applications
2015 (English)In: IEEE Transactions on Biomedical Circuits and Systems, ISSN 1932-4545, E-ISSN 1940-9990Article in journal (Refereed) Published
The measurement of the biological tissue’s electrical impedance is an active research field that has attracted a lot of attention during the last decades. Bio-impedances are closely related to a large variety of physiological conditions; therefore, they are useful for diagnosis and monitoring in many medical applications. Measuring living tissues, however, is a challenging task that poses countless technical and practical problems, in particular if the tissues need to be measured under the skin. This paper presents a bio-impedance sensor ASIC targeting a battery-free, miniature size, implantable device, which performs accurate 4-point complex impedance extraction in the frequency range from 2 kHz to 2 MHz. The ASIC is fabricated in 150 nm CMOS, has a size of 1.22 mm × 1.22 mm and consumes 165 μA from a 1.8 V power supply. The ASIC is embedded in a prototype which communicates with, and is powered by an external reader device through inductive coupling. The prototype is validated by measuring the impedances of different combinations of discrete components, measuring the electrochemical impedance of physiological solution, and performing ex vivo measurements on animal organs. The proposed ASIC is able to extract complex impedances with around 1 Ω resolution; therefore enabling accurate wireless tissue measurements.
Place, publisher, year, edition, pages
IEEE , 2015.
Diagnosis, Electric power systems, Electromagnetic induction, Histology, Implants (surgical), Medical applications, Physiology, Bio-impedance sensors, Discrete components, Electrical impedance, Electrochemical impedance, Implantable devices, Inductive couplings, Physiological condition, Physiological solution, Tissue
IdentifiersURN: urn:nbn:se:kth:diva-177619DOI: 10.1109/TBCAS.2015.2456242ISI: 000381440400001ScopusID: 2-s2.0-84941351785OAI: oai:DiVA.org:kth-177619DiVA: diva2:873686
FunderSwedish Research Council
QC 201511242015-11-242015-11-242016-09-30Bibliographically approved