Autonomous robotic subcutaneous injection under near-infrared image guidance

Subcutaneous injections are administered into the region beneath the skin, while avoiding puncturing the blood vessels, which gives many types of medications for various medical conditions. In this paper, a portable robotic system performing autonomous cannulation of subcutaneous injections is proposed, and it achieves to automatically locate the proper injection site by analyzing near-infrared (NIR) image sequences. The robot mainly consists of two functional modules-image processing module and motion control module. The former with a full-search algorithm processes the images obtained by the NIR equipment. The puncture point is selected in the area where there are no blood vessels and a method of "range square" is utilized. The motion control module of the robotic system employs the pulse width modulation (PWM) wave to effectively control the motors and manipulates the syringe to puncture at the selected point. The image processing algorithm was evaluated based on the real NIR images of volunteers' hands and forearms, and the image servo control of the robot was tested on the phantom. The experimental results were analyzed by a medical professional, and the success rate of the image processing algorithm is 96.09%, while the puncture time can satisfy the clinical demand for the efficiency of puncture procedures.