Body surface registration considering individual differences with non-rigid iterative closest point.

Purpose: In telemedicine such as remote auscultation, patients themselves or non-medical people such as patient's parents need to place the stethoscope on their body surface in appropriate positions instead of the physicians. Meanwhile, as the position depends on the individual difference of body shape, there is a demand for the efficient navigation to place the medical equipment.

Methods: In this paper, we have proposed a non-rigid iterative closest point (ICP)-based registration method for localizing the auscultation area considering the individual difference of body surface. The proposed system provides the listening position by applying the body surface registration between the patient and reference model with the specified auscultation area. Our novelty is that selecting the utilized reference model similar to the patient body among several types of the prepared reference model increases the registration accuracy.

Results: Simulation results showed that the registration error increases due to deviations of the body shape between the targeted models and reference model. Experimental results demonstrated that the proposed non-rigid ICP registration is capable of estimating the auscultation area with average error 5-19 mm when selecting the most similar reference model. The statistical analysis showed high correlation between the registration accuracy and similarity of the utilized models.

Conclusion: The proposed non-rigid ICP registration is a promising new method that provides accurate auscultation area takes into account the individual difference of body shape. Our hypothesis that the registration accuracy depends on the similarity of both body surfaces is validated through simulation study and human trial.