System Design And Implementation Of The Full Automatic Device For CTCs Separation,enrichment And Staining

This article aims to present an effective method of separating,enriching and staining CTCs,short for circulating tumor cells that is an important factor of causing death by tumor metastasis.This method is of great significance in therapeutic effect monitoring,in vitro diagnosis,tumor recurrence monitoring and the prediction of overall survival time.Current methods include gradient centrifugation technique and size separation technique,which have the problems of complicated operation,slow enrichment speed and low accuracy of CTCs enrichment.To solve these problems,the full automatic device for CTCs separation,enrichment and staining using u-TAS filter membrane is developed based on the negative pressure principle.The device has the characteristic of being highly efficient and reliable for the doctor to make diagnose for the cancer patients.Firstly,the technical specifications of the device are raised.Based on the requirements,the mechanical system is designed.The reagent platform is driven in or out of the device by the DC motor.And CTCs are separated from the normal blood cells by the suction force generated by the peristaltic pump.The stains platform is controlled ups and downs by the stepper motor to absorb the stains from the stains containers and inject the absorbed stains into the reagent tube by the syringe pump.Then the peristaltic pump absorbs the stains waste from the reagent tube and the stains waste is discarded into the stains waste container,finishing the entire separation,enrichment and staining of the CTCs experiment.Secondly,the hardware circuit is designed to have the full control of peristaltic pump,syringe pump,DC motor,stepper motor and photoelectric sensor and liquid level switch sensor by the slave computer,including power supply circuit,level conversion circuit,stepper motor driver circuit,DC motor driver circuit,peristaltic pump driver circuit,syringe pump driver circuit,pressure sensor driver circuit,photoelectric sensor driver circuit,liquid level switch driver circuit.To realize the interaction between the user and the system,LCD display circuit is designed based on the Smart210 master computer.The RS232 communication circuit is designed to accomplished the communication task between the master computer and the slave computer.Thirdly,the software is developed on the slave computer and the master computer respectively.The driver software is developed on the STM32 chip to control the hardware,such as the peristaltic pump,syringe pump and so on.The software developed on the master computer provides the user with the interactive platform to operate the whole system.The parameters of the sample blood and the reagents are input through this interactive platform and sent to the slave computer.And then the software on the STM32 deals with these parameters to control the mechanical part of the system to operate.The designed mechanical system,hardware system and the software system cooperate together as a whole.The electromagnetic compatibility is test to make sure that the device is working properly in different circumstances,which includes conducted emissions testing,and radiated emissions testing.The CTCs separation and enrichment experiment is performed using the designed CTCs device.The sample deviation tests,the sample repeatability error test,the interception rate test and the enrichment rate test all proves the reliability of the designed device for CTCs separation,enrichment and staining.The result of the research project demonstrates the promising future of the device for CTCs separation,enrichment and staining in the clinical application.