Improving Estimation Accuracy of Nasogastric Tube Tip Position Using Predata

A nasogastric tube is commonly used to pour nutrients into the stomachs of patients who have difficulty swallowing in order to provide them with the required nutrition. However, it is possible to inadvertently insert the tube into the lungs. Thus, a method of obtaining the tip position of the tube is desired. In this paper, we use predata of magnetoimpedance (MI) sensors to estimate the position of the magnet attached to the tube tip using a minimum variance beamformer. Experimental results show that the position estimation error is <;10 mm even when the distance from the MI sensors is 150 mm using the predata, whereas the error exceeds 10 mm when the predata is not used. These results suggest that the proposed method is a promising method for hospital applications.