Method and application of designing rehabilitation instrument based on single chip microcomputer

1. Introduction

Human balance ability is the basis for people to carry out various sports. People need balance ability to stand, sit, lie down and walk. Once a person's balance ability is impaired, his or her ability to move will be restricted, which will bring great inconvenience to learning and life. In modern society, the problem of population aging is prominent. Elderly people suffer from brain damage caused by certain diseases, which leads to reduced balance ability and impeded mobility. Therefore, in clinical treatment, a device that can test the balance function is needed. With the cooperation of Shanghai Ruijin Hospital, our school has successfully developed a multifunctional human balance rehabilitation instrument based on the analysis of relevant international and domestic data and the application of advanced computer control technology. The instrument can be used to test, analyze and train the balance function objectively and quantitatively, and can accurately perform static testing and dynamic training of balance ability. It provides an effective means for clinical research.

2. Instrument function

· Instrument measurement range: 10-360kg.

· Center of gravity position: ±1.0mm.

· Power supply 220V AC.

· The instrument can provide center of gravity distribution map, displacement map, balance radar map, center of gravity spectrum map, and can perform quantitative analysis of human balance ability.

·The instrument can test the trajectory of the human body's center of gravity in both static open-eye and closed-eye states.

·The instrument can provide dynamic testing and training for the body's balance ability.

3. Design principle of the balance rehabilitation instrument

The balance rehabilitation instrument measures the trajectory of the human body's center of gravity and analyzes the trajectory of the center of gravity to obtain a series of data on the body's balance ability. The center of gravity of an object is the point of action of the combined force of the gravity of each part of the object, while the center of gravity of the human body is the point of action of the combined force of the gravity of each part of the human body. When the human body stands, there will inevitably be slight shaking and swaying, and any movement of each part of the human body will cause the change of the center of gravity position of the human body. Therefore, these slight shaking and swaying will inevitably cause the change of the center of gravity position of the human body. This change in the center of gravity position reflects the degree and law of the shaking and swaying of the human body, and is an important basis for studying the state of the human body's balance function.

Therefore, in the balance rehabilitation instrument, we use gravity strain gauges and single-chip machines to form a gravity test platform to measure the center of gravity motion trajectory of the human body when standing in real time. The measured center of gravity motion trajectory data is transmitted to the host computer through the RS-232 serial interface. The gravity test platform tests 30 center of gravity motion trajectory data per second. In the host computer, VISUAL BASIC visual language programming is applied to calculate and analyze the center of gravity motion trajectory data transmitted by the gravity test platform, and then the dynamic trajectory diagram, center of gravity distribution diagram, displacement diagram, center of gravity spectrum diagram, balance radar diagram and parameter table of the human body center of gravity motion are drawn. The center of gravity motion trajectory of the human body can be tested in two ways: with eyes open and with eyes closed. Clinicians can judge and treat the condition by observing and analyzing the graphs and parameter tables.

In order to help patients with balance disorders restore their balance ability, patients need to be trained in balance ability. In the balance rehabilitation instrument, we use VISUAL BASIC visual language and multimedia technology to design a dynamic balance ability training program. In this program, language, music and dynamic graphics are used to enable patients to train their balance in a pleasant and relaxing virtual environment. They can also choose a training intensity that suits their balance ability to conduct rehabilitation training for their balance ability. Clinicians can also choose a suitable plan to conduct rehabilitation training and treatment for patients' balance ability, or conduct dynamic tests of their balance ability.

In the balance rehabilitation instrument, the measurement of the movement trajectory of the human body's center of gravity is the key to the instrument. In order to make the test platform easy to use and calibrate, we use a single-chip microcomputer to perform real-time measurement of the movement trajectory of the human body's center of gravity, and a PC to process data and generate the required graphics. [page]

4. Structure of the rehabilitation instrument

4.1 Schematic diagram of the structure of the rehabilitation instrument

In the figure, gravity sensors 1-6 are weight sensors of model NEA-60kg, which are installed at the three corners of the two test platforms to measure the motion parameters of the human body's center of gravity. The output signal of the gravity sensor is connected to the single-chip microcomputer, which measures the dynamic trajectory of the human body's center of gravity at a sampling rate of 30 times per second and transmits the data to the PC computer through the RS-232 serial port. The measured data is processed in the computer and the corresponding image display is generated, and it can also be recorded through the printer.

4.2 Test platform

There are two test platforms, each of which is composed of a 45 cm equilateral triangle 5 mm thick steel plate and three gravity sensors. The three sensors are evenly distributed on the three vertex corners of the test platform, and the measurement range of each sensor is 0-60 Kg. The average weight of a person is less than 100 Kg. Considering the impact force of a human body standing on it, the load of the test platform we designed is 0-180 Kg, so the total load of the two test platforms is 360 Kg. After testing, the test platform is fully able to withstand, and an anti-overload device is installed next to the gravity sensor of each test platform.

4.3 Human body center of gravity motion trajectory measuring instrument

The measuring instrument uses the AT89C52 CPU chip compatible with the MCS-51 series microcontroller. The built-in 8K bytes of flash memory can be repeatedly erased and written 1000 times, and the data can be stored for 10 years. The microcontroller has low power consumption and is easy to modify the program. It is responsible for real-time data collection and transmission. The measurement signal transmitted by the sensor is converted into a frequency signal and input through the T0 port of the AT89C52 microcontroller. It has high measurement accuracy, is convenient for photoelectric isolation, and has strong anti-interference ability. The sampling of the human body's center of gravity motion trajectory is implemented through the principle of moment balance in mechanics. The instrument evenly distributes three force sensors on the three corners of the measuring platform. When a person stands on the measuring platform, the center of gravity of the human body is transmitted to the force sensor through the measuring platform. The single-chip computer continuously detects the signal output by the sensor, and performs mechanical calculations based on the principle of moment balance to find the trajectory of the human body's center of gravity. The measurement accuracy of this project is ±0.1kg. The single-chip computer collects and processes the trajectory data of the human body's center of gravity, connects it to a MAX-232 chip through the RS-232 serial port, and exchanges information with the PC through the MAX-232 chip to complete the real-time measurement of the trajectory of the human body's center of gravity.

4.4 Data processing and image generation system

Using a PC computer, under the Windows operating platform, the serial port programming function of Visual Basic is used to read the data transmitted by the single-chip computer. After the data is processed, four pictures and one table are formed, including the center of gravity distribution map, displacement map, balance radar map, center of gravity spectrum map, parameter table, etc.

In terms of human-computer interaction, the information of the logged-in tester includes name, clinic number, height, weight, age, gender, etc., and is assisted by multimedia such as language, music, and background images.

Visual Basic, referred to as VB, is a visual language and a language development tool in the Windows environment. In the process of program development, especially in graphics processing, there is no need to write code to describe the appearance and position of interface elements. Just drag and drop the pre-established objects to a point on the screen. In the VB environment, by using event-driven programming mechanisms, novel and easy-to-use visual design tools, using the application program interface (API) functions inside Windows, as well as dynamic link libraries (DLL), dynamic data exchange (DDE), object linking and embedding (OLE) and open database access (ODBC) and other technologies, you can efficiently and quickly develop powerful and graphically rich application software systems under the Windows environment.

5. Project application prospects

Internationally, there have been studies on the use of computers to test and analyze human balance ability, and some domestic units have also developed static balance instruments. The human balance rehabilitation instrument we developed this time is based on the advantages of existing balance instruments, fully understanding the clinical diagnosis requirements of Shanghai Ruijin Hospital, and developing a balance rehabilitation instrument with dual functions of static testing and dynamic training. In terms of static testing, it contains more parameters, and in terms of dynamic training, it includes both rehabilitation training content and clinical research. The instrument can be used for both clinical treatment and clinical research, and has a wide range of applications.

With the growth of my country's aging population and the modernization of life, diseases related to human balance ability are increasing, and the demand for research and treatment in this area is also increasing. Imported instruments are expensive, with each instrument costing about hundreds of thousands of yuan, and there is no Chinese translation function, which is very inconvenient to use and difficult to develop twice. The instruments we developed ourselves are better than imported ones in terms of function, and the price is only tens of thousands of yuan, which is one-third to one-quarter of the imported instruments, and it is easy to develop twice. With the popularization of medical insurance and people's emphasis on health, the demand for medical equipment such as human balance rehabilitation instruments will develop greatly, and this low-priced instrument is easier to enter community hospitals. We believe that the balance rehabilitation instrument will be widely used in clinical treatment and clinical research, contributing to human health and improving the quality of human life.