The general process of blood management business is: integrated blood donation registration, blood sample detection, blood collection, blood bank, in-house management (component processing, etc.), blood out of the bank, and a hospital for use by patients (or other blood products) In this process, a large amount of data information is often involved, including blood donor information, blood type, blood collection time, location, and person handling. A large amount of information brings certain difficulties to the management of blood. In addition, blood is a substance that is very easy to deteriorate. If the environmental conditions are not suitable, the quality of blood is destroyed. Therefore, the quality of blood during storage and transportation Real-time monitoring is also critical. RFID and sensor technology are emerging technologies that can solve the above problems and effectively help blood management.
RFID technology can provide each bag of blood with its own unique identity and corresponding information for its depositors. These information are interconnected with the back-end database. Therefore, whether the blood is at the blood collection point, the blood bank is mobilized, or the hospital is used , Can be monitored by the RFID system throughout the process, and the blood information at each transfer point can be tracked at any time. In the past, it was time-consuming and labor-intensive to evacuate blood from the bank. Before use, it was necessary to manually check the information. After using RFID technology, data can be collected, transmitted, verified, and updated in real time without mass positioning. Library identification also avoids the errors that often occur during manual verification. The non-contact identification feature of RFID can also ensure that blood is identified and detected under conditions that will not be contaminated, reducing the possibility of blood being contaminated. It is also not afraid of dust, stains, low temperature, etc., and can store special blood Keep working normally under environmental conditions.
Sensing technology is a window for sensing, acquiring and detecting information. It can realize data collection and quantification, processing fusion and transmission applications. Through the real-time monitoring and collection of blood environment temperature, sealing condition and oscillation degree by sensors, and the timely processing and response of the sensing information by the system, it can effectively avoid the deterioration of blood and ensure the quality of blood.
Fusing RFID and sensing technology, using RFID sensor tags that can improve identification efficiency, achieve information tracking, and monitor the quality of items in real time, can truly achieve intelligent information management of blood management.
Design of RFID sensor tags
RFID sensor tags are mainly composed of micro control unit, sensing unit, radio frequency unit, communication unit, positioning unit and power supply unit, as shown in Figure 1.
Application of RFID sensor tags in blood quality control management
1 Micro control unit
The micro control unit is composed of embedded system, including embedded microprocessor, memory, embedded operating system, etc., and also integrates watchdog, timer / counter, synchronous / asynchronous serial interface, A / D and D / A converter, I / O and other necessary functions and external devices. The main functions realized by this unit include: responsible for the task allocation and scheduling of the entire chip, data integration and transmission, wireless data verification, data analysis, storage and forwarding, routing maintenance in the regional network, and power consumption management of the chip power supply Wait.
2 Sensor unit
The sensor unit is mainly composed of sensors and A / D converters. A sensor is a device or device that can sense a specified measurement and convert it into a usable output signal according to certain rules. Generally, the sensor is composed of a sensitive element and a conversion element. The sensitive element collects external information that needs to be sensed and sends it to the conversion element. The latter completes the conversion of the above physical quantity into the original electrical signal that can be recognized by the system and passes through the integration circuit and amplification circuit The reshaping process is finally converted into digital signals by A / D and sent to the micro control unit for further processing.
Considering the requirements of blood storage and transportation on environmental conditions, this sensor unit includes the function of testing multiple physical signals such as temperature, pressure, light sensitivity, oscillation, etc. in the monitoring area.
3 RF unit
The radio frequency unit controls the reception and transmission of radio frequency signals, and chooses to use access methods such as space division multiplexing, time division multiplexing, frequency division multiplexing and code division multiplexing to achieve multi-target simultaneous recognition and system anti-collision mechanism.
4 Communication unit
The communication unit is used for data communication, to solve the carrier frequency band selection, data transmission rate, signal modulation, coding method, etc. in wireless communication, and to send and receive data between the chip and the reader through the antenna, with data fusion, request arbitration and routing Select other features.
5 Positioning unit
The positioning unit realizes the positioning of the chip itself and the positioning of the information transmission direction. Based on wireless transmission protocols, such as IEEE802.15.4 standard and ZigBee protocol. The positioning algorithm can be based on ranging (such as signal strength ranging, time difference ranging, etc.) or non-based ranging methods (such as centroid method, DV-Hop algorithm, etc.).
6 Power supply unit
RFID sensor tags are classified as passive, semi-passive and active. Passive tags do not require a built-in battery in the chip, it maintains its work by extracting the radio frequency energy emitted by the reader. Both semi-passive and active tags require internal battery power to maintain normal sensing and RF operation. Considering that the real-time monitoring of blood products in blood management needs to ensure its continuous and normal energy supply, a power supply unit is added and designed as a semi-passive or active tag .
In this part, by properly setting the chip's receiving, transmitting and standby states, the problems of energy consumption and transmission reliability can be solved, and the service life of the chip can be effectively extended.
Application of RFID sensor tags in blood management
Mainly introduces from the three aspects of blood storage management, blood tracking management, blood quality control management, pointing out the effective role of RFID fusion sensing technology in blood management.
1 Management of blood storage
(1) Blood storage
The staff put the blood bag at the population of the conveyor belt and passed it in turn. An RFID reader was installed at the bottom of the conveyor belt. When the RFID sensor label attached to the blood bag entered the reading and reading range, the information on the label was read out. After filtering the middleware, it is transmitted to the back-end database. At the same time, the system displays the blood type, type, and specifications on the screen at the exit of the conveyor belt. According to the displayed content, the staff puts the blood in the designated storage tray.
According to the read blood type, type, specification, quantity, etc., the back-end system recognizes the location in the blood bank and finds the existing empty location that meets the specifications and quantity. This step is mainly achieved by pasting an RFID tag on each shelf, and writing the information of the blood type, type, specification, quantity, etc. it should be stored through the reader, when there is a blood bag on this shelf When going on, the staff uses the handheld reader to set and write the RFID tag. When the blood bag on the shelf is out of storage or shifted, the staff uses the handheld reader to clear the RFID tag and write , And the reader installed on the top of the blood bank will read each shelf label when instructed by the system, and find that the rack that has been cleared and meets the storage conditions will notify the system, and the system will The specific number is displayed on the screen at the warehouse, telling the staff what kind of blood should be placed on which shelves.
After being instructed, the staff will send blood of various specifications to the designated area for cold storage. At the same time, the reader writes the storage time, storage type, blood donor, and blood recipient of each blood bag into the RFID system
(2) Blood out of storage
The system issued a shipping order, instructing the staff to take the specified type, specification and quantity of blood to the designated area. If the amount of blood taken is small, the staff can use a handheld reader to read the blood information directly; if the amount of blood taken is large, the staff can use a conveyor belt to transport the blood out of the library and read its information. The read information is transmitted to the system and checked against the back-end database. If it is correct, it is allowed to leave the warehouse. During the delivery process, the RFID system records the delivery time, blood expiration date and other secondary information.
The order of blood out of the library is determined after the system reads the information and analyzes it. The blood of the same specification is required to follow the first-in first-out principle to avoid the phenomenon of inventory backlog and blood overdue waste. The blood marked as "waiting for inspection" in the blood bank is forbidden to be discharged, so as to ensure the quality of the discharged blood.
2 Blood tracking management
Blood tracking management uses a cluster-based hierarchical structure. Each cluster head is a distributed information processing center, which is used to collect the data of each cluster member and complete the data processing and fusion, and then pass the data to the cluster head of the upper layer, and then pass it in turn. Finally, all the data is filtered and After the integration, the cluster head is transmitted to the highest layer, and the reverse process is the information query process. The data is expanded layer by layer and tracked in an orderly manner. Here, the cluster head at the highest level is equivalent to the blood information center of the country, and the cluster head at the second highest level is equivalent to the blood information centers in provinces, autonomous regions, and municipalities. By analogy, the cluster members at the lowest level are the basic blood stations. This hierarchical structure disperses the information, avoids centralized storage, solves the problem of excessive information volume, and improves the security of the system. Information exchange and transmission are carried out directly between the child layer and the parent layer, which facilitates query and tracking. The structure is shown in Figure 2.
The procedure for depositing blood information is as follows: first, store the RFID identification code of each bag of blood and its corresponding information in the database of the primary blood station, then fuse the information of the primary blood station, and store the identification code with the effective IP of the primary blood station The address is stored in the database of the local municipal blood information center, and then the information of the municipal blood information center is merged, and the identification code and the effective IP address of the municipal blood information center are stored in the local provincial blood information center database. Re-integrate the information of the provincial blood information center, and store the identification code and the effective IP address of the provincial blood information center in the national blood information center database (if necessary, you can also re-identify the code and the national blood information center The effective IP address is stored in the global blood information center database, and the global blood information is interconnected) [6-7].
The tracking process of blood information is: according to the RFID identification code, first go to the national blood information center database to find the province information of the bag of blood, and enter the provincial blood information center database to find the bag of blood according to the IP address found. For city information, enter the database of the municipal blood information center according to the found IP address to find the blood station to which the bag of blood belongs, enter the blood station database according to the found IP address, and you can know the current status of the bag of blood according to the information in it Whether the status is stored in the library or is used out of the library or has been deteriorated and scrapped. If it has been used, you can further find all the information of the user.
3 Blood quality control management
Blood is very sensitive to temperature changes. If the ambient temperature is not suitable, the substances in the blood will be destroyed, which will affect the quality and shelf life of the blood. During storage, transmission and transportation, blood should also avoid violent oscillations. In addition, the packaging of blood should be sealed. If bacterial contamination is caused by puncture or other factors, the blood will be scrapped.
Application of RFID sensor tags in blood quality control management
The RFID sensor tag attached to the blood bag will monitor the environment around the blood bag in real time, measure the physical signals such as temperature, pressure, light sensitivity, oscillation, etc. at regular intervals, and record the measurement data in the tag chip . The system will set a standard range for the tag. Once the current measured data is below the lower limit of the range or higher than the upper limit of the range, the tag will actively send a radio frequency signal to activate the alarm device to prompt the staff.
If the blood bag is alarmed in the state of blood bank preservation, then according to the received radio frequency signal, the current position of the alarm blood bag (bank area, shelf, RFID identification code, etc.) will be displayed on the alarm display screen, which is convenient for the staff to find and Treatment; if the blood bag is to be alarmed during transportation, the alarm device can be installed on the transport reservoir, and the staff can be alerted by whining or flashing. After the staff discovers, the radio frequency signal is received by the handheld reader and the alarm is found according to the identification code Blood bag.
Once the blood is suspected of deteriorating or being contaminated, the staff will use the reader to set its label to the "waiting for inspection" state, and it is not allowed to leave the library. It is not allowed to be used at the point of use. It will be autoclaved and incinerated. At this time, the staff will write scrap information, scrap reason, etc. to the RFID identification code of the bag of blood to prepare for the follow-up blood tracking.
For the returned blood, in addition to the need to further detect the blood quality manually, you can also find out the problematic links in the entire process of the blood from blood collection to blood supply to the returned blood through the data recording of the RFID sensor tag, and find out who should be responsible The person or organization analyzes the reasons to avoid the next similar situation.
Blood is not only a source of life, but also a channel for the spread of various diseases. Common diseases transmitted through blood transfusion or blood products are: hepatitis B, hepatitis C, AIDS, syphilis, malaria, sepsis, etc., most of which are difficult to cure. In order to avoid disease transmission or medical accidents caused by irregular blood collection, disordered management of bagged blood, or improper blood transfusion, it is imperative to strengthen blood management and ensure blood safety. At present, the combined application of RFID and sensing technology is not very extensive, but it has shown a broad application prospect. This paper presents the RFID sensor tag designed by combining these two technologies, and analyzes the advantages and feasibility of applying it to blood management.
Blood management is a work that does not allow errors. The use of RFID sensor tags not only makes the entire supply chain management visible, transparent, and free from pollution, but also enables real-time monitoring and interconnected tracking of information and quality. Management informatization and medical management informatization work have been extended to the end and implemented, so that fully individualized humanistic care has been realized.