Research on positioning perception system in medical industry

Positioning awareness system is an important part of ubiquitous computing. The so-called positioning awareness means that the system center dynamically obtains the user's location information within a certain accuracy, and actively provides various services required by the user. In the traditional "request-response" service model, users must first make a request to the service system to obtain the required information, and the system responds and gives a reply, providing information in the required format. This system, called "passive mode", cannot meet the user's dynamic information needs, cannot actively and intelligently provide services, and does not meet the requirements of ubiquitous computing.

The positioning awareness system is an "active mode" system that can provide services to many users at the same time. The system can actively broadcast to users based on the information it has obtained, explaining the services it can provide, and users can obtain their own information according to their needs. Therefore, the "active mode" must have two functional systems: "positioning system (Orientation System)" and "location system (Location System)". The focus of the "positioning system" is to know the location of the object, while the focus of the "location system" is to know the set of objects at a specific location.

In the medical industry, both positioning information and location information are very important information. For example, positioning can play a role in emergency rescue or medical care, and location information can tell what kind of patients are in a specific location, what kind of medical services are needed, etc. With the continuous development of the informatization of the medical industry, the positioning perception system is gradually being built in the medical industry, bringing leapfrog development to the medical industry. An omnipresent rescue network, an accurate and fast equipment and drug management network, and a safe and timely patient information network not only improve the service capabilities of the hospital, facilitate information communication within the hospital, but also ensure the safety of patients' lives. Below, we will discuss and look forward to the positioning perception system in the medical industry based on the structure of the positioning perception system and the existing level of medical informatization.

Structurally speaking, the positioning perception system can be divided into the following five parts: system control center, transaction processing center, communication environment, positioning system and location system (Figure 1).




1 System Control Center

The system control center is the control and management center of the entire system. It is responsible for transmitting location information or object set information to the transaction processing center and transmitting location information to the "location system". It must be able to process a large amount of various information in real time and perform analysis and detection.

In recent years, major hospitals in China have been building digital hospitals. "Digital hospitals" are hospitals that use advanced computer and network technologies to collect, store, transmit and integrate various types of information such as patient diagnosis and treatment information, health economic information, drug information, and hospital management information in the most effective way, and optimize various business processes and maximize information utilization. The hospital information management system (HIS: Hospital Information System) used by these hospitals realizes the function of the system control center. It is the control and management center of the entire hospital and even the medical industry. It can transmit and process a large amount of medical information in real time, and some of them are even data from the emergency scene.

2 Transaction Processing Center

The transaction processing center is the service sender and processing unit of the entire system. It receives various information from the system control center, or responds to user service requests, or actively broadcasts various useful information to users. The system control center distributes many more detailed tasks to various transaction processing centers. For example, the nurse workstation in the hospital HIS system is a typical transaction processing center.

3 Communication environment

The communication environment provides support for information transmission in various parts. In terms of the positioning perception system, we hope to build a wireless network world. The emergence of technologies such as wireless wide area network and wireless local area network provides a very good platform for realizing the communication environment of positioning perception system.

Wireless wide area network (WWAN) technology allows users to establish wireless network connections through remote public networks or private networks. These connections can cover a large geographical area by using several antennas or satellite systems maintained by wireless service providers.

Wireless local area network (WLAN) is a network that uses wireless communication technology to replace traditional cables and provides device access functions. It is a new technology that combines computer networks with wireless communication and mobile communication technologies. In the development of wireless local area networks, international standards including IEEE802.11a, 802.11b, 802.11g, HiperLAN/2, etc. have been formed, and the network access rates that can be provided range from 11Mbps, 22Mbps to 54Mbps.

4 "Positioning system" and "positioning system"

"Positioning system" and "positioning system" are important functional systems of positioning perception system, and both positioning information and position information are inseparable from the application of wireless positioning technology. Commonly used wireless positioning technologies include: infrared positioning technology, global positioning system (GPS), ultrasonic positioning system, IEEE802.11 positioning system and radio frequency identification (RFID) positioning system. Each positioning technology has different characteristics and positioning accuracy. With the help of wireless network platform, RFID positioning and tracking system is a direction that has been studied more recently.

Radio frequency identification technology (RFID) is a non-contact automatic identification technology. Its basic principle is to use the coupling or propagation of electromagnetic waves in space to communicate, so as to achieve the purpose of automatically identifying the identified object and obtaining relevant information of the identified object. The simplest RFID system consists of three parts: tag, reader and antenna. With computer network and software support, it can form an RFID application system (Figure 2). RFID uses radio technology for communication, and information is stored in a small silicon chip in the tag. After the tag enters the magnetic field, it receives the radio frequency signal sent by the reader, and uses the energy obtained by the induced current to send out the information stored in the chip (Passive Tag, passive tag or passive tag), or actively sends an encrypted signal of a certain frequency (Active Tag, active tag or active tag); the reader reads the information and decodes it and sends it to the central information system for relevant data processing.



5. Building a positioning perception system in the medical industry




Based on the structural characteristics of the positioning perception system and the existing level of informatization in the medical industry, starting from today's IT technology, we can build a basic framework for the positioning perception system in the future medical industry (Figure 3): wireless network as the communication environment, the constantly upgraded HIS system as the system control center, and RFID technology as the main positioning technology and information acquisition technology.

In fact, as early as 1997, the United States Patent and Trademark Office approved a patent No. 5629678, and the licensee was a natural person. This patent mainly protects a technology that implants an RFID chip in the body and uses a global positioning system to implement global positioning and identity recognition. It maintains a sensor network. This network can actively monitor the environment and record and send relevant information. The rescue center can obtain the location, movement route, identity, emergency situation, rescue methods, etc. of the person at any time through the global positioning system. In theory, this technology can be used to detect the physical condition of each person, actively detect the diseases, environmental hazards and personal attacks encountered by the person, and automatically send all necessary rescue information. Judging from the technical features described in the patent, such an RFID wireless network has already tended to meet the requirements of the positioning perception system.

In December 2004, the U.S. Food and Drug Administration officially approved the application of Applied Digital Solutions Co. (ADS) to sell RFID chips in the medical industry. ADS's VeriChip is an RFID chip about 12 mm long and shaped like a "grain of rice". The chip records the identification (ID) information of the implanter and is implanted under the skin of the upper arm. VeriChip has a dedicated "reading and scanning device". The weak radio waves emitted by the scanning device pass through the skin to reach VeriChip, providing it with weak energy. After obtaining this energy, VeriChip sends the implanter's ID information, which is received by the scanning device. This ID information is sent to the database center managed by ADS through the network. The database center records the past medical and health information of the contracted members and can be called up at any time as needed. Although this technology has caused widespread controversy in the United States, as far as the positioning perception system is concerned, the VeriChip chip implanted in the human body makes the network, equipment and people more closely integrated, which meets the development requirements of the positioning perception system.

In addition to information acquisition, positioning using RFID technology is a very important part of our construction of a positioning perception system. The accuracy of wireless positioning is a challenging research topic now and in the future. For simple positioning of finding a person or thing in a small area, RFID technology is fully capable and has been applied in many occasions. For precise positioning using RFID, the typical representatives are the SpotON system and the LANDMARC system. The SpotON system develops an aggregation algorithm based on signal strength analysis to locate in three-dimensional space. The hardware tags in the system are distributed in a network, without the need for a central control unit, and the geometric distance between tags is characterized by the signal strength tested by the tags. The LANDMARC system can obtain higher positioning accuracy by introducing reference positioning tags and using a residual weighting algorithm between different tags. However, these two systems are still in the experimental research stage. Because the complexity of the actual application environment has a great influence on the positioning accuracy, using RFID for precise positioning is an important direction for future research and an important part of building a positioning perception system.

Under the existing technical conditions, RFID positioning and tracking systems have begun to be used in some hospitals. Combined with wireless networks and HIS systems, all patients, visitors, and medical staff can be equipped with RFID electronic tags for tracking according to the scale and nature of the hospital or the classification of the diseases being treated. They can be monitored on the floor plan of the hospital, and the situation of all monitored objects will be clear at a glance. With the advantages of timeliness and mobility of wireless networks, vital signs data and medical data can be queried and entered at any time. Doctors' rounds, bedside care, call communications, nursing monitoring, drug distribution, and patient identification code recognition have all become transparent digital services. At the same time, query statistics and analysis can also be done, including: on-site personnel inventory (including number, distribution, personnel information, etc.), regional historical record query (people or objects that have appeared in a certain area within a certain period of time), personnel (object) historical record query (in which areas specific objects have appeared), alarm historical record query (statistical event occurrence patterns), and main material inventory and whereabouts (such as plasma, organs, test samples, etc.).

6 Conclusion

The concept of ubiquitous computing has been formed for more than ten years, and the research on positioning perception systems has always been one of the most important areas in ubiquitous computing. The application of emerging technologies such as hospital information management systems, wireless networks, and RFID has enabled us to see that modern technology has gradually built a prototype of a positioning perception system in the medical industry. Although the current prototype is still a long way from the world of complete integration of information space and physical space in the concept of ubiquitous computing, especially in terms of precise positioning, we believe that with the continuous improvement of science and technology, the positioning perception system will truly take shape in the medical industry, which is closely related to life. By then, a small chip will actively detect dangerous signals from our body and the external environment in real time, and it will act as a personal doctor to protect people's safety at all times.