In-Vivo Tissue Identification on Mice Using a Fiber Optical Tip Force Sensing Needle

This paper presents in-vivo tissue identification on mice by our recently developed novel fiber optical tip force sensing needle. The needle can directly measure the axial force required to penetrate a tissue at its tip, which can then be used for in-vivo identification of tissues. Both ex-vivo and in-vivo tissue experiments were carried out on 32 mice. Ex-vivo tissue insertions were conducted on dead mice to study the influence of time of death on needle tip force, body temperature change, and the results of tissue identification. The in-vivo experiments focused on the difference in tissue identification from the ex-vivo experiments. In addition, a tip penetration force database of mouse tissues was established through dissected mice within one minute of death. By means of this database, experiments for tissue identification were carried out. Results show that the tip force sensing needle has the capacity to identify the organs during needle insertions.