Three-dimensional measurement of tip position of catheter in ultrasound volume through time-series analysis of microbubble dispersion

Because there is a limitation of radiation exposure for a patient, and an X-ray equipment is generally huge and expensive, ultrasound has a potential to replace X-ray image as a monitoring method of catheter located in human body. To realize a diagnosis or a therapy using a catheter under monitoring with ultrasound, the most fundamental problem is visualization of the catheter. The visualization of catheter itself on ultrasound images is strongly affected by the material of catheter and ultrasound parameter. Therefore, we propose a method to detect the tip position of catheter in ultrasound volume by time-series analysis, where microbubbles were released from the tip of the catheter and showed spatial dispersion in ultrasound volume. We confirmed the effectiveness of the algorithm through a phantom experiment and in vivo experiment, where the candidate volume of the tip was determined with the accuracy of several mm.