Contactless in-vivo temperature sensing in spinal cord based on magnetically bistable microwire

• Published in: Sensors and actuators. A. Physical. Vol. 366; p. 115007
• Main Authors: Milkovicova, Jana, Bacova, Maria, Sulla, Igor, Slovinska, Lucia, Galik, Jan, Varga, Rastislav
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2024
• Subjects: In-vivo sensing; Magnetic microwires; Spinal cord; In-vivo sensing; Spinal cord; Magnetic microwires
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2023.115007

We have employed a magnetically bistable glass coated microwire as a passive contactless sensing element for in-vivo temperature monitoring in the rat’s spinal cord. The single piece (1 cm long) of Fe76Cr2Mo6B15Cu1 microwire was epidurally implanted into the adult female Wistar rats. The magnetization switching was measured in-vivo within the temperature range of 34.5–41.0 °C. Results show a monotonous temperature decrease of the switching time whose fitting to a second order polynomial dependence allows one to conclude a sensitivity down to 0.01ºC within the measured interval. Biocompatibility study shows that cells have a high affinity to the glass-coated microwire, and their viability is not influenced by the experimental condition under which the microwire’s response is measured. Finally, a histology study reveals that no histopathological changes or tissue reactions were observed even after 9 months of implantation. [Display omitted] •In vivo passive contactless temperature sensor based on bistable magnetic microwire.•Glass coating provides excellent biocompatibility.•Sensitivity down to 0.01 °C within temperature range 35 – 41 °C.