Design of networked intelligent monitoring system for nursing home environment

Introduction

As the aging of the population in China gradually intensifies, the problem of empty-nest elderly people has become prominent and has become a new focus of the aging problem. According to statistics, the number of empty-nest families in large cities is close to 30%, while the number in the three municipalities of Beijing, Shanghai and Tianjin is as high as more than 33%. Empty-nest elderly people have poor living ability and great economic pressure, and nursing homes are undoubtedly an ideal choice for their later life. Introducing the concept of comprehensive network monitoring into nursing homes and establishing a networked intelligent monitoring system can improve the quality of services for the elderly and the disabled, change the traditional elderly care methods, and actively face the challenges in the future elderly care field.

Previous research on technologies for helping the elderly and the disabled was mostly carried out on intelligent devices with specific functions, and did not introduce the concept of comprehensive network monitoring. In recent years, many units at home and abroad have carried out research on comprehensive networking of medical care, elderly care and disability assistance. In the "Mobile Nursing System with Early Warning Mechanism" jointly developed by the Department of Electronic Engineering of National Taiwan University and the Department of Electronic Engineering of Taipei University of Technology, the portable device used to measure the physiological parameters of the elderly transmits signals through a Bluetooth module, then connects to a GSM mobile phone, and aggregates the information to the monitoring center through mobile phone text messages. Although this method expands the communication range through GSM, the signal is transferred through the mobile phone, which makes the system structure complicated and increases the cost. In addition, GSM has large radiation and is not suitable for long-term continuous use. European and American medical institutions mostly access Ethernet (IEEE 802.3) through WLAN (IEEE 802.11) devices, which has better realized the early warning and processing of sudden cases and emergency situations, which is worth learning from.

With the continuous maturity of Ethernet and WLAN technology, their transmission rate, security and stability are also constantly improving. This paper uses WLAN portable monitoring equipment to access Ethernet, and combines hot technologies such as RFID, video surveillance, database and human-computer interface development to achieve seamless connection between the elderly's condition and the monitoring center.

1 System overall structure

At present, most of the large nursing homes and welfare homes in China have good accommodation conditions, with an occupancy rate of up to 100%, and queuing for admission is common. However, there are few people engaged in medical monitoring in these institutions, and the facilities for helping the elderly and the disabled are relatively old and the technical level is backward, which greatly limits the understanding of the physical health of the elderly.

Real-time monitoring of the elderly's life characteristics, nursing conditions, range of activities and other information can not only understand the current health status of the elderly in real time, but also predict the future situation of the elderly. The overall structure of the networked intelligent monitoring system of the nursing home is shown in Figure 1. The elderly can not only obtain physiological parameters such as blood pressure, pulse, and body temperature regularly through portable wireless monitoring equipment (i.e., the equipment around the elderly in Figure 1), but also identify the active RFID tag signal to determine the location, and access the wired network through the base station to aggregate the information in the monitoring center. The monitoring center can understand the elderly's various information in real time and store it for future analysis and viewing. In case of emergency, the monitoring center can switch the video monitor based on the positioning information, and dispatch the corresponding rescue personnel to the exact location of the incident for treatment based on the physiological parameters, thus achieving the optimal integration of limited human resources and completing the coordination and unification of information and video linkage monitoring, monitoring and rescue.


2 Network structure design

The monitoring system network consists of two parts: data monitoring network (gray) and video monitoring network (black), as shown in Figure 1.

2.1 Data monitoring network structure design

The data monitoring network is divided into two parts: wired network (Ethernet) and wireless network (WLAN).

(1) Wired data monitoring network

Considering the inconvenience of bus-type networking and high implementation cost in the traditional industrial control field, Ethernet with strong networking capability, high reliability, high speed, low cost and wide application range is selected as the wired data monitoring network part. In addition to aggregating wireless networks, this part is mainly used to monitor medium and large terminal devices with poor mobility in the elderly's room, such as medical care beds, air conditioners in apartments and various entertainment and rehabilitation equipment in activity centers.

(2) Wireless data monitoring network

WLAN adopts CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) type media access mechanism to comply with Ethernet protocol (CSMA/CD, Carrier Sense Multiple Access/Collision Detection) and is compatible with mainstream network operating systems. It can be connected to Ethernet through wireless AP without any modification; WLAN radiation is much lower than ordinary GSM mobile phones, which is more environmentally friendly. In addition, WLAN has good mobility, strong scalability and high transmission rate compared with other mobile communication technologies (such as Bluetooth and Zig Bee).

Since the WLAN is used outdoors, TENDA's TWL5401A with a TENDA 24 dB mesh directional antenna is selected as a wireless access point. TWL5401A is an outdoor long-distance AP, which uses a highly sealed, corrosion-resistant, anti-interference aluminum housing and IEEE802.3a/PoE Ethernet power supply. It has a wide coverage range (unobstructed 2 km), supports AP, point-to-multipoint, relay and wireless client modes, has high sensitivity, and cooperates with the watchdog and the latest wireless security standard WPA2 to make wireless communication safe and reliable.

The wireless terminal integrates pulse, blood pressure and temperature sensors. First, the photoelectric sensor is used to indirectly measure the pulse rate by testing the blood's ability to absorb light intensity, then the pressure sensor is used to measure blood pressure, and finally the temperature is measured by the temperature sensor. The positioning of the elderly is a low-precision regional positioning, so the centroid positioning algorithm based on the RFID signal can meet the requirements. The wireless terminal can use TI's medical low-power chips, such as the OPT101 photoelectric sensor and the FG47x series MCU. For RFID, you can choose active tags and readers from Beijing FiberHome Liantuo or Shanghai Xiupai.

2.2 Design of video surveillance network structure

The video surveillance network consists of various surveillance cameras (panoramic, low-light, etc.), a large screen in the monitoring center, and video transmission lines. The system cooperates with the data monitoring network to realize the linkage monitoring of image positioning, as shown in Figure 1. In areas where day and night monitoring is required, SONY SSC-DC59xx series cameras can be selected to ensure that low-light monitoring requirements are met.

3 Analysis and application of network communication protocols

Ethernet/IP introduces TCP/IP on the basis of Ethernet, so the production of monitoring software can be simplified by using Socket. In addition, its abstract monitoring node is an object model, which provides a complete set of data access procedures and promotes product standardization. Finally, the Ethernet/IP underlying communication network can be supported by commercial Ethernet hardware, which is convenient to implement and cost-effective.

3.1 Communication protocol structure and data encapsulation

The protocol hierarchy of Ethernet/IP is shown in Figure 2. It defines data encapsulation, application and transport layers, and user layers on top of TCP/IP. Data access procedures (explicit, I/O information) are defined in the application and transport layers, and the user layer can customize application objects and their corresponding device lines.



The location of Ethernet/IP data encapsulation in the overall data encapsulation of the protocol (Ethernet frame) is shown below. For the specific encapsulation format of Ethernet/IP, please refer to the protocol volume.



3.2 Wireless terminal communication module

Taking the communication module of the wireless terminal as an example, its internal nodes are pathed and the object model is established as shown in Figure 3.


Data access procedure: Ethernet/IP data access is based on application connection, which ensures the security and reliability of data. If an explicit or I/O connection has not been established, the message must be sent to the message router for distribution through the unconnected message manager (UCMM). Explicit or I/O connections can be established through UCMM information through the connection management object. Explicit connections are used for irregular data access (such as blood pressure values) in the form of TCP questions and answers; I/O connections transmit real-time information on the scene (such as real-time location) through UDP.

Application objects and their equipment profiles: The application objects for establishing electronic blood pressure meters, thermometers, and real-time positioning modules are shown in Figure 4. The collection object binds the measured values ​​of the latter two to form equipment profile 2. The equipment profile defines the communication organization form of the data measured on the scene, and profiles 1 and 2 are shown in Figure 4.


The data organized in the form of the above-mentioned equipment line rules is first encapsulated by Ethernet/IP in its command-related data domain, and then the IP and TCP headers are added in turn and put into the Ethernet frame, and then uploaded from the site to the monitoring center.

4 Design of network monitoring software for the monitoring center

The system monitoring software integrates network programming, human-computer interface development and database technology. During the development, multi-threaded network programming based on Socket is involved. In view of the strong support of VC++ for multi-threading and its high code execution efficiency, it is selected as the development language. Considering the large amount of real-time data and its processing efficiency, and in order to ensure the security of the data, SQLserver is selected as the system background database. In order to reduce the amount of development code and improve the software execution performance, ADO is selected to operate the database.

The functional flow of the monitoring software shows the entire process of the monitoring center from establishing a connection to data communication for a certain field node.

Conclusion

The comprehensive network monitoring concept is applied to the nursing home environment. The system networking is completed through the comprehensive application of technologies such as Ethernet, WLAN, RFID and video surveillance, which truly realizes the all-round and all-weather linkage monitoring of the elderly. In addition, while introducing Ethernet/IP protocol into the network for assisting the elderly and the disabled, the monitoring software development process is given, providing a complete and safe and feasible nursing home network intelligent monitoring solution, which is worthy of reference for related project development.