Development Of Embedded System For Platelet Function Analyzer With Dual-module Architecture

Platelets are one kind of the most important blood cells in the human body.The number and aggregation ability of platelets are of great significance for the prevention and diagnosis of cardiovascular and cerebrovascular diseases.In order to enhance the system management ability and improve the assay efficiency,the design and implementation of embedded system for platelet function analyzer with dual-module architecture is presented in this dissertation.Dual-module architecture is an effective way to improve assay efficiency,the control,communication and operation management of which are complicated,therefore the embedded system is in higher requirements.The dual-module assay system consists of liquid circuit,actuating mechanism,management module and two control modules,which realizes dual-channel parallel assay.The interference between channels is greatly reduced due to the independence of control modules.Control modules control actuating mechanism to complete single platelet assay by the sub-process of dilution,adding agent,counting and cleaning.Management module is responsible for human computer interaction,and the SPI protocol is used to communicate with control modules to complete platelet assay task.When two control modules work at the same time,the synchronization of blood cell counting sub-process are implemented for further reducing the interference between channels.The high performance processor AM3358(Cortex A8)is chosen for redesigning embedded system for management platform based on the existing platelet function analyzer.A variety of standard hardware interfaces are expanded and amounts of underlying software is transplanted which promotes running speed,storage and expansion capabilities.The platform is general and can be applied to many kinds of medical instruments.At the same time,the signal detection algorithm of control modules is redesigned and the details of SPI communication is optimized which improves the reliability of the system.Firstly,the background and motivations of the research and development are introduced,with related works summarized and discussed.The requirements of assay system are analyzed from the aspects of embedded system for management platform,assay efficiency,interference between channels,assay parameters and operation management function.Aiming at the problem of assay efficiency and interference between channels,the scheme of dual-module assay system is proposed.Then,the design principle of the embedded system based on AM3358 processor for management module is discussed,and the implementation of hardware interface circuit,printed circuit board,underlying software is given in detail.The optimization of control modules is given from the aspects of parameter setting,assay process control,blood cell signal processing and reliable SPI communication.At the same time,the implementation of dual-module synchronization is proposed.Then,the structure and design principle of embedded operation management software for dual-module assay system is discussed,and the implementation of multiple assay modes,assay process,data storage and query,precision control and upload is described in detail.Finally,the test results of dual-module assay system based on the new management module are given,and the easy operability,assay efficiency,repeatability and reliability of the system are verified.