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Electro Mechanical Reshaping (EMR) with platinum needle electrodes has been recently developed to shape cartilage
without conventional cut and suture surgery. This study investigates the relationship between the voltage applied, the
electrical current measured during EMR, and the resulting shape. Monitoring the electrical current provides information
to model the electro-chemistry, which will aid in determining the onset of shape stabilization. Porcine costal grafts,
rabbit auricular, and porcine auricular tissue were bent into a 90° angle using a moulage. Platinum needle electrodes
were then placed in contact with the cartilage and a constant voltage was applied for a set time. The electrical current
was measured during the process and total charge transferred was calculated. The cartilage specimen was then removed
from the jig and photographed after one minute in order to determine the resulting bend angle. Results show that a higher
current in tissue is produced with increasing applied voltage. Each current trace is unique and is dependent on tissue
thickness and inter-electrode distances. Understanding the electrical current process ultimately leads to optimizing EMR
and feedback control. Voltage, for example, could be varied in real-time during EMR to produce a constant chemical
reaction rate and potentially reduce total tissue dehydration in contact with electrodes. In conclusion, electric current
traces provide information about chemical kinetics during EMR that depend on exposure settings, and monitoring these
traces is an important step in optimizing the reshaping process.
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