Home monitoring of bone density in the wrist-a parametric EIT computer modeling study

Goal: The purpose of this computer modeling study isto validate the feasibility of a home monitoring system for wrist bone mineral density (BMD) measurement whichis based onthe parametric electrical impedance tomography (pEIT) method. Methods: A solution tothe forward problem of the developing potential around the wrist due to current injection was developed using a Matlab numerical simulation of an adult computer human phantom. The backward problem issolved by building a lookup table of different bone densities which represent different disease stages. Results: The real part of the complex potential exhibitsanaverage change of 30.7%-12% (between the most sensitive and the least sensitive electrodes) per BMD decrease of 23%. A 2 times higher sensitivity to a deterioration of the cortical bone than of the trabecular bone alone was found. A signal to noise ratio (SNR) level above 30 dB isrequired for a maximal performance of the system. The robustness toa deposition of the electrodes array in different directions is limited. Conclusion: It was found that the cortical BMD changes govern the model. The required SNR level iswithin the specs of similar systems. In a real device, the issue of sensors repositioning should be addressed. The proposed pEIT system makes self-monitoring of wrist BMD possible. Itbrings anadded-value byenabling the monitoring of BMD between treatments and between traditional DEXA screenings.