Application of DICOM Standard in Portable Medical Equipment

1 Introduction

Radio Frequency refers specifically to electromagnetic waves with a certain wavelength that can be used for radio communications. Radio Frequency Identification (RFI) is a non-contact automatic identification technology that began to emerge in the 1990s. It uses the transmission characteristics of radio frequency signals and spatial coupling (inductive or electromagnetic coupling) or radar reflection to achieve automatic identification of objects to be identified. However, at present, there are still many bottlenecks in the development of RFID, and the low data reading rate is one of the main bottlenecks.

This article will analyze the RFID system by introducing the basic composition and working principle of the RFID system. Combined with the problems encountered in the actual application of the RFID system and the reasons for the low reading rate of the system due to factors such as blind spots in the reader's reading range, redundant data at different reading points, and mutual interference between readers, it is proposed to improve the data reading rate of the RFID system from four aspects: reasonably optimizing hardware configuration, improving software design, giving full play to the role of middleware, and integrating other technologies.

2 Basic components of RFID system

The RFID system consists of at least two parts: an electronic tag (E-Tag/Transponder, also known as a smart tag) and a reader (Reader/Interrogator, also known as a reader/writer).

Electronic tags are the data carriers of the radio frequency identification system. Electronic tags are composed of tag antennas and tag-specific chips. Electronic tags are divided into active tags, passive tags, and semi-passive tags according to different power supply methods; they are divided into low-frequency tags, high-frequency tags, ultra-high-frequency tags, and microwave tags according to different frequencies; they are divided into * tags, linear tags, paper tags, glass tube tags, round tags, and special-purpose shaped tags according to different packaging forms; they are divided into active tags and passive tags according to different working modes.

The reader is a device used to read or write electronic tag information. It can be designed into various types of products according to the specific use environment and requirements. The reader communicates wirelessly with the electronic tag through the antenna, and can read or write the electronic tag identification code and memory data.

A typical reader includes a high-frequency module (transmitter and receiver), a control unit, and a reader antenna. Of course, in actual application, the RFID system also requires the support of other hardware devices such as computers and software. Figure 1 shows the composition of a typical RFID system.

3 Basic Model of RFID System

The basic model of the RFID system is shown in Figure 2. The electronic tag as the radio frequency carrier and the reader realize the spatial (contactless) coupling of the radio frequency signal through the coupling element, and in the coupling channel, according to the timing relationship, the energy transfer and data exchange are realized.

4 Discussion on the reading rate of RFID system

Through the introduction of RFID system, we believe that the main reasons for the low reading rate of RFID system are: blind spots in the reading range of the reader, redundant data at different reading points, mutual interference between readers, etc. In response to the above problems, we discuss them from the following four aspects.

4.1 Reasonably optimize hardware configuration

In terms of hardware, you must first clarify one question. That is, what is your real "need". Don't blindly think that "the more expensive, the larger the reading range, and the higher the frequency, the better". As the saying goes, "tailoring clothes to your body" is the best. Based on this cognition, you can choose hardware devices that meet your actual needs.

At the same time, consider all RFID tags and readers as a complete "data network" and optimize the hardware configuration reasonably to maximize the effectiveness of the entire system. Taking the access control system as an example, in order to prevent the reader's reading range from having blind spots, resulting in missed readings, the number of readers or antennas can be increased to compensate for the defects of blind spots in the reader's reading range; in order to prevent readers from interfering with each other, readers or antennas can be relatively isolated in space to avoid mutual interference. In addition, according to actual needs, the data reading rate of the RFID system can also be improved by appropriately adjusting the antenna layout and antenna transmission power.

4.2 Improve software design

At present, the hardware facilities of the RFID system with optimized configuration can basically meet the needs of data reading rate, and as the price of readers drops, end users can easily deploy a large number of readers in their application sites, which not only solves the problem of missed reading, but also allows more useful information to be obtained from these systems. However, the new problem that comes with it is: redundant data reading or cross-data reading. To simply describe this problem, "a tag that should not be read at a certain location is read by a reader that should not read this tag."

The core of LV positioning logic is based on "picking out the required readout data from the spatial position while filtering out the unnecessary readout data". The result is that the correct and accurate tag position is extracted from the results obtained by all RFID readers. In short, LV positioning logic is a software algorithm based on eliminating "redundant" readout data based on the data set resident in the entire reader system. The Colorwave algorithm provides a good solution to the problem of conflicts between multiple readers due to overlapping working ranges.

For electronic tag conflicts, in high-frequency bands, the tag anti-collision algorithm generally adopts the classic ALOHA protocol. Tags using the ALOHA protocol avoid conflicts by selecting a method to transmit information to the reader after a random time; in the ultra-high frequency band, the tree bifurcation algorithm is mainly used to avoid conflicts. In addition, other optimization settings can be made to the software. For example, in the electronic ticket system, the scanning time interval of the reader can be designed to work in a way of adaptively adjusting the scanning time through software design. In the case of large flow of people, the scanning frequency of the reader can be accelerated through software control to prevent missed reading; in the case of small flow of people, the scanning frequency can be relatively reduced to avoid the appearance of redundant data.

4.3 Playing the role of middleware

RFID middleware is the nerve center of various RFID industry applications. RFID middleware is a message-oriented middleware (MOM). Information is transmitted from one program to another or multiple programs in the form of messages. RFID middleware plays the role of an intermediary between RFID tags and applications. From the application side, using a set of common application programming interfaces (APIs) provided by the middleware, it can connect to the reader and read the tag data.

Therefore, even if the database software or back-end application program storing RFID tag information is increased or replaced by other software, or even when the types of RFID readers increase, the application side does not need to be modified. This not only effectively solves the problem of data reading rate, but also saves other problems such as the complexity of maintaining many-to-many connections. RFID middleware will have very good development prospects in the future in terms of service-oriented architecture (SOA: Service Oriented Architecture Based RFID) and commercial information security issues.

4.4 Integration of other technologies

Fusion with sensor technology

In the next few years, an important application trend of RFID is to combine RFID with sensors (such as sensors for measuring temperature and pressure), which has been implemented abroad. Since RFID has poor anti-interference ability and its effective distance is generally less than 10 meters, this is a limitation to its application. Combining WSN (wireless sensor network) with RFID and using the former's effective radius of up to 100 meters to form a WSID network will greatly make up for the shortcomings of the RFID system itself.

Integration with WIMAX, 3G, GPS and other communication technologies

WiMAX (Worldwide Interoperability for Microwave Access) is simply defined as a wireless broadband data transmission system. The wireless service range of WiMAX can reach several kilometers in urban areas with high data traffic. Its performance far exceeds that of existing wireless network technologies. In directional communication connections, the service range can reach 50 km while maintaining a certain data traffic. Due to its extremely high performance, WiMAX technology is considered to be the best alternative to DSL UMTS connections.

The integration of WiMAX, 3G, GPS and RFID is advancing with the active participation of all parties. RFID tags have the characteristics of small size, large capacity, long life and reusability. They can support fast reading and writing, non-visual identification, mobile identification, multi-target identification, positioning and long-term tracking management. Cost savings and efficiency improvements have made RFID technology an important entry point for various industries to achieve informatization. They will build a wireless broadband network that can meet the needs of various application environments and generate rich applications, expanding the application field of RFID technology.

Fusion with biometrics

Biometric identification technology is a solution that uses automatic technology to measure physical features or personal behavioral characteristics for identity verification, and compares these features or characteristics with the template data in the database to complete the authentication. The biometric identification system captures the sample of biometric features, and the unique features will be extracted and converted into digital symbols, which are stored as personal feature templates. People interact with the identification system to authenticate their identities to determine whether they match or not. Currently, commonly used biometric identification technologies include fingerprint, palm print, face, voice, retina, signature recognition, etc.

In short, the integration of RFID systems with other technologies is imperative, and great results have been achieved so far. Solving the problem of low data reading rate of RFID systems will surely make RFID technology widely adopted, and eventually it will be as in-depth and slowly extended to all aspects of various industries as barcode technology, playing a key role in improving the efficiency and economic benefits of the industry, thereby promoting a new leap forward in the global economy and having a profound impact on human society.

5 Conclusion

Overall, the development of RFID system will be better and better in the future. Although there are still some technical and application problems such as low reading rate, we believe that it is not difficult to overcome the current problems of RFID through a series of measures such as hardware optimization configuration, perfect software design, middleware role and integration of other technologies. Under the strong market orientation, RFID technology will inevitably cause a major change in the world. It will become a new economic growth point in the future and will eventually become the largest information technology support for the development direction of Chinese enterprises. It can be foreseen that in the near future, as the global manufacturing base, China will be the world's largest RFID application market in the future. This will be a rare opportunity for domestic scientific research institutions and enterprises.