MEMS Gyroscope and the Ego-Motion Estimation Information Fusion for the Low-Cost Freehand Ultrasound Scanner

This paper presents the design and implementation of the fusion algorithm for a very low-cost medical ultrasound imaging system. The probe consists of only a single-element piezoelectric transducer which makes it challenging to reconstruct a geometrically correct 2-D ultrasound image. Minimal hardware has been used to reduce the manufacturing cost. Concepts of ego-motion estimation are used to estimate the lateral position of the probe rather than using a position sensor. Whereas an inexpensive microelectromechanical system (MEMS) gyroscope is used to measure the orientation of the probe. The orientation and position information are fused using the fusion algorithm proposed in this paper that gives the real-time 3-D position of the probe. This will enable a geometrically correct, 2-D, B-mode ultrasound image to be constructed from a very simple probe with a single fixed beam that is manually scanned across the skin. Previously collected in-vivo data of the fetus is analysed and 2-D image is reconstructed using the fusion algorithm that corrects the geometry of the fetus’s head.