Guiding Vascular Access with the Sonic Flashlight – Preclinical Development and Validation

Abstract

This dissertation concerns the development of a device called the Sonic Flashlight, which employs a novel method for viewing real-time ultrasound images inside the body exactly at the location where it is being scanned. While other augmented reality methods have previously been developed to view ultrasound and other medical imaging modalities within the body, they are generally much more complicated, slower and less robust than the Sonic Flashlight. In this dissertation, we aim to develop the Sonic Flashlight towards one particular clinical application, central vascular access, and lay the groundwork leading to the first clinical trials. The goal of central vascular access is to insert a catheter into a major vein to deliver medications in large quantities. These veins are usually not visible to the naked eye, so real-time ultrasound is employed to guide the needle into them. While real-time ultrasound guidance significantly enhances the safety of central venous access, learning this skill can be a challenge for the novice user, one major obstacle being the displaced sense of hand-eye coordination that occurs when the operator must look away from the operating field to view the conventional ultrasound monitor. We developed the 5th generation Sonic Flashlight, as well as a novel calibration method, called thin-gel calibration, as part of this dissertation. The thin-gel system allows us to accurately calibrate the Sonic Flashlight and measure the calibration accuracy. Finally, experiments were conducted with a variety of subject populations using vascular ultrasound phantoms and cadavers to validate Sonic Flashlight guidance, demonstrating that the device is ready for clinical trials.