Medical Alert Systems for Seniors No Monthly Fee

Medical Alert Systems for Seniors No Monthly Fee

With the continuous development and improvement of sensor technology and mobile communication technology, smart home, smart logistics, smart medical, and other fields continue to develop, using the short message service of GSM mobile communication, we have designed a smart medical alarm system.

This system uses the short message transmission function of GSM communication technology to realize remote wireless medical alarms. When the alarm information is sent from the sensor information processing unit, the main control MCU uses the AT command set specified by GSM70.05 to drive the SIM900A module to send an alarm message. The SMS controller passes through the processing of the information. Send information to the designated terminal. To realize the medical alarm.

The background and significance of the intelligent medical alarm system

With the development of society, the increasingly fast-paced life brings many safety problems, and fire hazards in high floors, large shopping malls, and other places. There have been frequent traffic accidents under high-speed traffic. The intelligent medical alarm system realizes timely and active alarm. It provides timely information for treatment and emergency rescue so that medical security personnel can respond to emergencies promptly. Provide the most timely information for the rescue of people.

medical alert systems for seniors no monthly fee
  1. Design Principle
    1.1 Sensor group
    To make the system application flexible, this sensor group adopts a modular hardware design. According to the function of the system, the sensor group originally designed is composed of two modules: an anti-fall module and an anti-fire module. Each module uses different sensors according to different functions.
    1.1.1 Falling alarm module
    Under normal circumstances, the main feature of the human body falling process is that the body is in a position close to the horizontal direction after a large impact, for example, the human body loses balance and lies on the ground after colliding with the floor after the impact. Therefore, a three-axis acceleration sensor and a two-axis angular velocity sensor (gyro) sensor form an information collection device, and the acceleration or angular velocity change during the fall of the human body is combined with the threshold method to determine whether to fall.
    To make the application of module integration flexible, this module is divided into an acceleration acquisition module, an angular velocity acquisition module, an information processing module. The first two can be combined with the information processing module to complete the required functions. Among them, to make the device light and portable, the acceleration acquisition module and the angular velocity acquisition module adopt the MPU6050 module that integrates a three-axis acceleration sensor and an angular velocity sensor.

1.1.2 Fire protection module
According to the “Code for Design of Automatic Fire Alarm”, the corresponding fire detector should be selected according to the state of fire. In the early stage of the fire, if it is mainly a smoldering fire, then a large amount of dense smoke will be generated, and only a small amount of heat will be emitted. For areas with only a small amount of flame radiation, smoke detectors should be selected; if the fire develops rapidly, and In areas with strong flame radiation but only a small amount of smoke and heat, flame detectors should be selected. The height of the room is different, and the sensor selected is also different. For ordinary houses, the height of the house is less than 4m, so it is more appropriate to choose a smoke detector and a flame detector. Based on the above considerations, this module uses an MQ-2 smoke sensor, DS18B02 digital temperature sensor, and flame sensor to detect fire signals.

medical alert systems for seniors no monthly fee

Medical alert systems for seniors no monthly fee

The circuit of this block is mainly divided into sensor circuit, AD circuit, 430 modules, buzzer, and power supply, as shown in Figure 10. After the sensor receives the fire signal, the analog quantity is converted into a digital quantity through the AD circuit, which is transmitted to the 430 modules, and then the information is transmitted through wireless communication. The structure diagram is shown in Figure 3, the principle diagram of the MQ-2 smoke sensor module is shown in Figure 4, the principle diagram of the flame sensor module is shown in Figure 5, and the principle diagram of the DS18B02 temperature sensor module is shown in Figure 6.

1.2 Main control information processing module

The mobile device control unit is mainly connected with the GSM module, GPS module, and I/O port, composed of MSP430F149 master control MCU. When the external I/0 port gets the alarm information of the sensor information processing module, the location information, time information, and the type of danger that occurs at that moment are used. Edit it as a short message and send it to the “SMS receiving and dispatching central control station” (name to be determined). Then, the central control station for sending and receiving short messages sends short messages to notify the pre-set users.

1.2.1 Block diagram of the main control information processing module

1.2.2 Function realization

  1. GPS positioning function realization

GPS, or Global Positioning System, is a global positioning system built-in 1994 in the United States. GPS is mainly composed of three parts: ground control station, satellite, and receiver. 27 satellites are 20,200km away from the ground. There are 24 satellites in operation and 3 in reserve. Each group of 4 satellites orbits the earth along 6 orbits. Generally, there are no more than 12 satellites on the same side of the earth. Most GPS The receiver can track 8-12 satellites. The GPS receiver can output 2D data when receiving signals from 3 satellites, only latitude and longitude, without altitude, if it receives more than 4 satellites, it will output 3D data, which can provide altitude and receive 6-8 satellites. Accurate positioning can be achieved only when. Due to the high sensitivity of capturing satellite signals, the single-point positioning speed of GPS handhelds is very fast. Generally, it can capture more than 4 satellites in about 15 seconds, to quickly realize 3D navigation and positioning.

Medical alert systems for seniors no monthly fee

There are two types of GPS signals: C/A code and P-code. General receivers can only receive C/A codes, and the horizontal position positioning accuracy is about 2.93m to 29.3m. The error of the P-code is 2.93-0.293m, which is only used by the US military. Due to the location of GPS satellites, the error of GPS measurement of elevation is generally larger, 2-3 times the horizontal error.

GPS is widely used in field geological work due to its all-weather, high-precision, low-cost, simple operation, and high efficiency. It provides great convenience for geological fixed points and greatly improves work efficiency, especially in the field. Flat terrain areas with unobvious landmarks.
The GPS module receives the satellite signal from the antenna, and the obtained satellite signal is sent to the MSP430F149 single-chip microcomputer in the form of ASCII code through the signal output pin on the GPS, and the single-chip extracts these signals to obtain the position information.

medical alert systems for seniors no monthly fee
  1. GSM module function realization

GSM (Global System for Mobile) is the world’s most important 2G standard, which can provide high communication quality under the conditions of low service and low terminal cost. In terms of its services, GSM is a mobile Integrated Services Digital Network (ISDN) that can provide multiple services.

The SMS (Short Message Service) used in this system is an application service provided by the GSM system that sends and receives text messages between GSM terminals through the service center, and the service center completes the information storage and forwarding function.

At present, the technology of GSM chip and GSM transceiver module is relatively mature, and there are ready-made modules available on the market. These chips and modules generally have all the functions of GSM wireless communication, provide a standard UART serial interface or RS-232 interface, support the AT command set defined by GSM07.05, and it is easy to achieve system integration.

After joining the SIM card, SIM900A recognizes the user information and can connect to the public network.
This system uses the single-chip microcomputer MSP430F149 as the controller, which is directly connected to the serial port of the module SIM900A. The single-chip microcomputer transmits the AT command to the GSM module through the serial port. The GSM module sends the signal to the short message center through the antenna, and the short message center forwards it to the short message controller. The alarm is realized.

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