Design and Fabrication of a Microinjector to Conduct Columnar Injection of Stem Cells for Treating Parkinson's Patients

Considering the rising prevalence of neurological diseases like Parkinson's, novel treatment methods have advanced significantly in recent years. One promising approach is transplanting stem cells into targeted brain regions, for which developing precise equipment is essential. A critical method for implanting these cells is columnar injection into brain tissue. The present research focuses on designing and fabricating a microinjector device for the controlled columnar injection of stem cells into the brains of Parkinson's patients. Inspired by existing microdrive models, the newly developed device stands out for using two motors as actuators, two encoders, and a PID controller. This configuration compensates for operational errors and environmental noise, ensuring precise injections at the required rate. The PID controller is designed using system identification, where equations governing the power transmission systems are derived and implemented. To verify the device's performance, the injection rate for a standard procedure (25 microliters at 1 microliter per minute) is measured using encoders and validated with a digital caliper. The instantaneous injection rate is calculated using the encoder and caliper data. While the average of these data is the same, the standard deviation of the caliper data is significantly lower than that of the encoder data. This indicates that the device is functioning as expected and that much of the noise in the encoder data originates from the sensor itself.