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Design And Analysis Of Human Body Composition Analyzer

However, most of the body composition analyzer has a simple measurement type, poor man-machine experience performance, this article on the market more popular SN-2A human body composition analyzer for a simple analysis. Using the Android platform data analysis technology to design and implement a multi-parameter, digital and intelligent analysis of the human body composition. The instrument front-end acquisition module adopts 8-point contact electrode acquisition mode, through the sub-segment measurement to achieve automatic multi-frequency detection, access to bio-electrical impedance of the human body, and the collection of data analysis and processing, through the Android platform to provide friendly human-computer interaction interface The The design hardware circuit structure is simple, low cost, to achieve the 30 kinds of Body Composition Analyzer of the measurement calculation, data exchange and data storage. In this paper, the Body Composition Analyzer system software design for a brief introduction. Key words: bioelectrical impedance; human body composition;

1 lower computer software design

The lower computer software uses C language programming, mainly by the main program, data acquisition, data processing and serial transceiver control and other four parts, the control chip by sending the corresponding command to control the physical parameters of the matching and data transceiver. After the system starts running, the lower computer main control chip power on, waiting for user measurement operation, followed by the input test number and personal information (age, gender, height, weight, etc.), the master chip to determine the input parameters to send the measurement instructions Control the analog front end for data acquisition, after the acquisition of instructions to trigger the analog front end and the main control chip to interact, will be amplified, AD converted impedance signal sent to the control chip for the corresponding signal processing, processing through the serial port after the packet Sent to the man-machine interaction module, show the basic parameters of the calculation results, and then come to the parameters of the target control analysis and the parameters of the indicators.

2 PC software system overview

Data display and user interaction in the Android platform to achieve. After the user logs in, the basic information such as height, weight, age, sex and so on is required to start the physical test. If the abnormality occurs in the measurement (the input information is out of range or the test channel is abnormal), the measurement process is automatically terminated. After successful measurement, the lower position machine requests the measurement result data. After the data is received, the data protocol is parsed, the bytecode is converted into text, the test report is generated, and the test result can be saved according to the user's need.

3 communication protocol

The lower computer and the host computer (Android motherboard) through the TTL serial port to communicate, the lower computer to calculate the physical indicators of data need to be converted to bytecode to send, and the host computer needs to be the lower port of the serial machine sent to the byte code read Into the cache and parse the corresponding numerical results, this process requires a mutually agreed agreement between the good communication protocol. According to the definition, the calculated value is converted into the corresponding ASCII code, the packet starts with the hexadecimal number 0xBC, the A byte is the type identification byte, the instruction type or the data type of the packet; the interval is 0xA5 Byte, used to separate the data; 0xD4,0xC6,0xC8,0xD44 bytes as the end of each packet, indicating the end of a packet. The host computer reads the byte stream from the serial port and stores it in the byte array. By looking for 0xBC bytes to find a packet header, separated by 0xA5, read each byte before the byte and according to the ASCII table converted into the corresponding value, and according to the specific agreement to draw the specific meaning of the value , And finally completed from the lower computer to the host computer detection results of the transmission.

4 data persistence

In order to save the data obtained for each test so as to generate a conventional test report at any time, it is necessary to carry out the data to be read every time. The data persistence scheme is roughly divided into database storage and serialized storage. As the system more testing items, the use of Android system SQL-Lite more inconvenient, so the system selects the serialized storage as a data persistence program. Serialization is the process of converting a data object into a bytecode. In this system, the host computer to resolve the data from the serial port to generate a specific array of test results, we will serialize this array into a byte stream and write to the test time named dat file, stored in the The host computer built-in SD card; when you need to read a certain time

Test results, the program to find the selected time dat file, write it into the byte stream, through the reverse deserialization of the test results obtained array; to ensure that the detection results of the object is immutable, the system uses a serialization Agent to carry out the serialization of test results.

5 Conclusion 

The design of the body composition analyzer is generally not too complicated, simple structure and good human-computer interaction. Using multi-band analysis of human components, making the output of the human body composition indicators with higher accuracy. I believe that the future of human body composition analyzer will lead the trend of the times.

Tongfang Health Technology (Beijing) Co.,Ltd