As for the design of the infusion set alarm device, I personally recommend that you don’t think about it, but it can be considered as a personal hobby. Because as early as two years ago, I accidentally saw an infusion alarm device, which was a two-system alarm using light and sound. But until now, I have not seen this patent popularized by any large hospital (if the hospital wants to make money, it can just arrange a nurse to follow it, and it is not cost-effective to increase medical costs on a large scale). So it has no real value.
But since you asked about the selection of sensors, you might as well start with the core of the sensor, that is, special resistors (photosensitive, sound sensitive, pressure change, etc.) and then select the characteristics you may use, and start from there. .
The above is just my personal opinion, I hope it will be helpful to you. Also attached is a patent description of the sensor mentioned above:
The utility model discloses an automatic alarm infusion set, which includes a puncture needle, a dropper connected in series through an infusion tube, a regulator and an injection device. Needle, a buffer tube is connected in series between the puncture needle and the dropper. A conduit is set on the buffer tube to connect to the transmitter. The transmitter is a cylindrical shell with a flange, and two electrode contacts are set on the top. There is a ventilation hole, and the electrode contacts are connected to the sound and light alarm through wires. A floating body is installed in the shell. The top of the floating body is equipped with a moving contact piece corresponding to the two electrode contacts. The flange cover with an air chamber and interface is connected to the The flange of the housing matches, and a diaphragm is installed between the flange of the housing and the flange cover. The utility model has a simple structure and is easy to use. When the infusion is about to end, it can automatically send out an alarm signal to notify the patient and the nurse, thereby allowing the patient to rest at ease during the infusion process and eliminating the need for family supervision.