Characterization of liquid jet injection into tissue based on optical coherence tomography

We present the combination of high speed video monitoring, force measurement and Optical Coherence Tomography (OCT) as a new method for the characterization of liquid jets for needle-free tissue injection applications. It is well known that physical parameters, such as jet velocity and jet diameter determine the penetration characteristics of liquid micro-jets into a specific tissue [1]. The optimum injection parameters vary significantly for different types of tissues. Therefore, we have used high speed video monitoring and force sensor measurements to characterize the liquid jet. The penetration into the tissue is then analyzed by Optical Coherence Tomography (OCT) [2]. This enables the general description of the specific jet's physical properties as well as the penetration characteristics with respect to a specific tissue. In the experimental study, jets with diameters of 100 μm and jet lengths from 6 to 18 ms (~ 2 to 9 μl) have been injected into colon tissue from pigs.