Development of automatic puncture method to simulated blood vessel in semi-transparent skin model by noncontact position estimation using IR cameras

• Published in: Kikai Gakkai ronbunshū = Transactions of the Japan Society of Mechanical Engineers Vol. 89; no. 917; pp. 22 - 22-00262
• Main Authors: SAGAWA, Koichi, FUJIMOTO, Takuto, KOIDE, Tatsuya, NAGAI, Chikara
• Format: Journal Article
• Language: English; Japanese
• Published: The Japan Society of Mechanical Engineers 2023
• Subjects: automatic puncture; control; image processing; position estimation; robot; simulated blood vessel
• ISSN: 2187-9761; 2187-9761
• DOI: 10.1299/transjsme.22-00262

A noncontact estimation method of three-dimensional position of simulated blood vessel in an artificial skin model and an automatic puncture method are proposed. Unlike the conventional 3D position measurement method which requires detection of specific points from captured images, the simulated blood vessel filled with simulated blood is captured using two infrared cameras and the vessel image taken is approximated by a linear equation. The two equations of the plane containing the linear equation and the focus of each camera are obtained. The intersection of two planes is the center axis of the simulated blood vessel and is defined by a 3D linear equation. A six degree-of-freedom robot is developed to perform automatic puncture. The position of puncture needle is controlled by cartesian coordinate mechanism to achieve high reliability and precision when operating in three-dimensional space. The direction of needle is controlled by rotational mechanism using two stepper motors with small backlash. Straight movement of puncture needle toward the simulated blood vessel is achieved by a linear actuator activated using a DC servo motor. A three-dimensional force sensor attached at the needle and a photo interrupter placed across the blood collecting tube are employed to monitor puncture procedure. Sudden decrease in puncture force indicates the penetration of upper wall of simulated blood vessel. Light blocking in photo interrupter shows blood flow into tube. Twenty kinds of automatic puncture experiments are performed on simulated blood vessel of 2 mm or 3 mm in diameter and 4 mm or 6 mm in depth, changing direction every 10 deg from 20 deg to -20 deg in phantom which simulates mechanical characteristics of human skin. Experimental results show that 17 experiments were successfully punctured, and the effectiveness of the position estimation method of simulated blood vessel and control method of puncture robot system are confirmed.