A flexible needle-catheter tissue-anchoring device was developed to accomplish full-thickness tissue apposition of the GI wall.
In order to test the planning algorithm, it is coupled with a fast needle insertion simulation involving a flexible needle model and soft tissue finite element modeling, and experimented on the use-case of thermal ablation of liver tumors.
The generated force was determined from the deflection of the flexible needle.
In the current study, a novel computed tomography (CT -guided free-hand ISBT approaCT -guidedlastic flexible needle applicators was developed.
The stiffness of the flexible needle was 0.1 1.0 μN/ μm (resonant frequency 3.0 10.0 kHz in solution, depending on the needle stiffness), which was determined by the cross-calibration method (24).
The tongues were pulled aside and purified γδ T cells were instilled into the trachea by a syringe with flexible needle, and mice were then infected intranasally with S. pneumoniae 24 h later.
The transmission image of the flexible needle was projected onto a quadrant photodiode (S4349, Hamamatsu Photonics, Shizuoka, Japan), and the output signal was collected by the data acquisition system (PowerLab, ADInstruments, Colorado Springs, CO) to measure the developed force.
The deflection of the flexible needle due to the laminar flow during the force measurements was negligibly small, as the viscous drag applied perpendicular to the myofibrils due to the flow is estimated to be in the order of 10−9 N. The solution around the myofibril was exchanged within 30 ms by moving the capillary with a stepping motor SGSP20-355, Sigma Koki, Tokyo, Japan).
The flexible plastic needles in our study eliminated artifacts on CT images, allowing for a clear visualization of needle implantation and easy contouring of target tissues and OARs.
