New Multi-view Cardiac Ultrasound Imaging System Based on Optical/Inertial Tracking

The main idea of this project is to develop a novel approach to fuse multiple view 3D ultrasound line and planar scans using a portable 6D optical/inertial tracking system. Recent advances in echocardiography allow for the real-time acquisition of three-dimensional heart models. However, one of the major limitations of 3D echocardiography is the limited field-of-view (FOV), which may lead to models that do not cover the whole heart geometry. New methods to improve the FOV and image quality have been introduced by acquiring multiple conventional single-view 3D datasets with small transducer movements. These methods rely on image registration to align single-view images which requires sufficient overlap to obtain accurate alignment. In this project, we propose a method that relies on a new portable 6D (position and orientation) optical/inertial tracking system mounted on an ultrasound (US) imager to perform image alignment. This tracking system will allow us to solve image alignment as it eliminates the constraints on image overlap and quality as the accuracy of the alignment obtained by the tracking system is far superior to the image resolution of an US sensor. In a pilot project, we used an optical tracing system to fuse images from a dynamic heart phantom to demonstrate that the proposed method yielded accurate alignment of image volumes in 3D space. During that test, it became apparent that despite its high-precision, optical tracking alone is not sufficient to be practical in a real clinical setting due to occlusions and size.  The main idea is to adapt a new tracking system developed by Intersense based on a new portable InertiaCam sensor, which is comprised of MEMS inertial sensors combined with a smart camera capable of  tracking markers in real-time. The camera is used to compensate for the inertial system drift. Our goal is to install numerous (3) InertiaCam sensors on a new cellphone-sized General Electric (GE) VSCAN US system and on the patient’s chest to monitor breathing displacements. The synergetic combination of these technologies with our multi-view integration technology funded by the CISCO Chair will make this system unique and may revolutionize cardiac US imaging. GE, manufacturer of the VSCAN, is very interested in this project and is ready to help us integrate the tracker into the US transducer and to eventually commercialize the system.