Real-Time Wireless Platform for In Vivo Monitoring of Bone Regeneration

• Published in: Sensors (Basel, Switzerland) Vol. 20; no. 16; p. 4591
• Main Authors: Blázquez-Carmona, Pablo, Sanchez-Raya, Manuel, Mora-Macías, Juan, Gómez-Galán, Juan Antonio, Domínguez, Jaime, Reina-Romo, Esther
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 15-08-2020; MDPI AG
• Subjects: Animals; Bone Regeneration; Bony Callus; calibration; callus stiffness; external fixator; External Fixators; load sensor; Metatarsal Bones; Monitoring, Physiologic; Radiography; Sheep; wireless acquisition system; bone regeneration; callus stiffness; load sensor; calibration; wireless acquisition system; external fixator
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s20164591

For the monitoring of bone regeneration processes, the instrumentation of the fixation is an increasingly common technique to indirectly measure the evolution of bone formation instead of ex vivo measurements or traditional in vivo techniques, such as X-ray or visual review. A versatile instrumented external fixator capable of adapting to multiple bone regeneration processes was designed, as well as a wireless acquisition system for the data collection. The design and implementation of the overall architecture of such a system is described in this work, including the hardware, firmware, and mechanical components. The measurements are conditioned and subsequently sent to a PC via wireless communication to be in vivo displayed and analyzed using a developed real-time monitoring application. Moreover, a model for the in vivo estimation of the bone callus stiffness from collected data was defined. This model was validated in vitro using elastic springs, reporting promising results with respect to previous equipment, with average errors and uncertainties below 6.7% and 14.04%. The devices were also validated in vivo performing a bone lengthening treatment on a sheep metatarsus. The resulting system allowed the in vivo mechanical characterization of the bone callus during experimentation, providing a low-cost, simple, and highly reliable solution.