Single-channel Isolated Microvascular Tension Determination System, model 320A is manufactured by RWD Life Science Co.,LTD Two stainless steel wires passed through the lumen of the isolated microvessel, and the two wires were tied to both ends of the fixation frame. One end of the fixed frame is connected to a microspiral ruler to stretch and control the circumference of microvessels; the other end is connected to a tension transducer to measure the tension changes of microvessels during contraction and relaxation in real time. There is a glass window at the bottom of the bath, and the bath can be placed on an inverted microscope for fluorescence observation. It can also be connected to a physiological recorder to output analog signals.