Localization of epidural space in piglets by catheter-based swept source optical coherence tomography

In an operation requiring epidural anesthesia, a puncture needle is advanced progressively into the epidural space, and medication is then injected into this space. The space is very shallow, so there is too little room for adequately positioning the tip of the needle. Excessive advancement of the needle beyond the space and an inaccurate shot of medicine will cause a medical accident. In this study, we designed and built a needle-fiber based Fourier domain swept source optical coherence tomography (SSOCT) system. An optical fiber attached to a focusing lens was put into a puncture needle and a fiber-based fast scan SSOCT system was built up. The reflected signal was captured by a balanced detector that can improve the signal to noise ratio.