Methods for monitoring the temperature of blood products during cold chain transportation

Abstract

This invention discloses a method for monitoring the temperature of blood products during cold chain transportation, comprising the following steps: providing an RFID-based multi-tag radio frequency identification system, including a reader, a passive coupling antenna, and coated RFID tags; fixing RFID tags to a primary packaging unit and a passive coupling antenna to a secondary packaging unit; filling each primary packaging unit with blood products; using the reader to collect and store the temperature information of the blood products filled in the primary packaging unit, thereby achieving full-process monitoring of the temperature of blood products during cold chain transportation; the surface of the RFID tag is coated with a magnesium aluminum silicate coating comprising a mixture of hexadecyl alcohol and octadecyl alcohol in a weight ratio of 10:3. The method of this invention exhibits excellent results, especially the tags, which have excellent adaptability to industrial environments.

Description

Technical Field

[0001] This invention belongs to the field of cold chain transportation of blood products, and relates to a method for monitoring the temperature of blood products, especially human serum albumin, transported in the cold chain. In particular, it relates to a multi-tag radio frequency identification system based on radio frequency identification technology, which improves the reliability of temperature monitoring results for these blood products, especially human serum albumin, under temperature fluctuation conditions. Background Technology

[0002] Human serum albumin is the earliest and most widely used blood-based biological product in clinical practice. Because it can maintain the osmotic pressure balance of body fluids and blood colloids, detoxify, transport endogenous or exogenous substances, resist shock, and provide nutrition, it is mainly used clinically for shock caused by burns, trauma or blood loss, extracorporeal circulation, increased intracranial pressure, adult respiratory distress syndrome, therapeutic plasma exchange, and edema and ascites caused by kidney disease or cirrhosis.

[0003] Radio Frequency Identification (RFID), a reflective communication technology, is widely used in logistics, public transportation, access control systems, and many other scenarios. RFID consists of RFID readers and RFID tags. RFID readers are active devices that transmit information to RFID tags by transmitting modulated high-frequency carrier waves. RFID tags are mostly passive devices that use load modulation technology to change channel conditions, a change that can be detected by the RFID reader, allowing it to read the tag's information. Currently, most RFID tags lack sensing capabilities and cannot be externally coupled with specific sensors to collect specific information, which greatly limits their application scenarios. For example, in a centralized container containing multiple identical items, real-time monitoring of information such as temperature typically requires batteries, which increases monitoring costs and may also cause secondary pollution.

[0004] The inventors of this application disclose an RFID-based multi-tag radio frequency identification system and method in CN113283259B. This system includes independent RFID readers, passive coupling antennas, and multiple RFID tags. The passive coupling antennas and multiple RFID tags are placed within a preset space. The RFID reader is radio frequency coupled to multiple RFID tags through the passive coupling antennas and is used to read multiple RFID tags simultaneously. Specifically, the RFID tags are RFID tags with interfaces and separate transmit and receive antennas. The RFID reader is an RFID reader with interfaces and separate transmit and receive antennas.

[0005] Based on CN113283259B, the research team of the inventors disclosed a method for uniformly monitoring the temperature of pharmaceutical products transported in cold chain within a batch in CN118761702B, comprising the following steps: providing an RFID-based multi-tag radio frequency identification system, which includes independent RFID readers, multiple passive coupling antennas, and multiple RFID tags, wherein the RFID reader is equipped with a data storage device; attaching RFID tags to each primary packaging unit by adhesive method, attaching passive coupling antennas to each intermediate packaging unit by adhesive method, wherein each primary packaging unit is filled with at least one pharmaceutical product unit, and each intermediate packaging unit... The unit contains at least one primary packaging unit. An RFID reader attached to the cold chain transport vehicle collects temperature information of the pharmaceuticals within each primary packaging unit and stores the collected information in a data storage device. Throughout the cold chain transport of the pharmaceuticals, the RFID reader collects and stores temperature information of the pharmaceuticals within each primary packaging unit at fixed or variable intervals, thereby achieving full-process temperature monitoring of the pharmaceuticals during cold chain transport. Before being attached to the primary packaging unit, the RFID tag is pre-coated with a magnesium aluminum silicate coating composed of micronized magnesium aluminum silicate, povidone K30, and lanolin mixed in a certain proportion. This invention can reduce the difference in measurement results caused by excessively low temperatures within the same batch of drugs, thereby achieving uniform and accurate temperature monitoring of pharmaceuticals transported in the cold chain within the batch.

[0006] However, the aforementioned RFID-based cold chain technology still has some shortcomings in the cold chain transportation of blood products such as human serum albumin. In particular, the RFID-based multi-tag radio frequency identification system provided in the method for uniformly monitoring the temperature of pharmaceutical products transported in cold chain within a batch as described in CN118761702B still has some aspects that need improvement. For example, the RFID tags themselves exhibit problems that need improvement after undergoing stability tests simulating high and low temperatures.

[0007] Therefore, those skilled in the art still look forward to having a method for monitoring the temperature of pharmaceutical products, especially biological products such as blood products, particularly human serum albumin, during cold chain transportation, especially with RFID tags used in such a method having excellent performance. Summary of the Invention

[0008] The present invention aims to provide an RFID-based multi-tag radio frequency identification system for temperature monitoring of pharmaceutical products, especially biological products such as blood products, particularly human serum albumin, during cold chain transportation. Another objective of the present invention is to provide a method for monitoring the temperature of pharmaceutical products, especially biological products such as blood products, particularly human serum albumin, during cold chain transportation, including products requiring cryogenic storage.

[0009] This invention is based on the technology implemented by the inventors' research team using Chinese patents CN113283259B and CN118761702B. Through improvements, the method and system of this invention can monitor the temperature of cold-chain transported pharmaceutical products, especially biological products such as blood products, particularly human serum albumin, with excellent batch uniformity. This invention is based on such discoveries. The entire contents of the referenced documents, especially the aforementioned two patent documents, are incorporated herein by reference.

[0010] Therefore, the first aspect of the present invention provides a method for monitoring the temperature of blood products transported in a cold chain, comprising the following steps:

[0011] S1. A multi-tag radio frequency identification system based on RFID is provided, comprising independent RFID readers, multiple passive coupling antennas, and multiple RFID tags. The RFID readers are equipped with data storage. The RFID tags are coated with a magnesium aluminum silicate coating on their surface in the following manner: micronized magnesium aluminum silicate, povidone K30, and a mixture of cetyl alcohol and octadecyl alcohol are mixed in a weight ratio of 3:1:1, added to 8 times their weight of ethanol, stirred, and heated to 65°C to dissolve the povidone K30 and cetyl alcohol mixture and uniformly suspend the magnesium aluminum silicate to obtain a suspension. This suspension is then uniformly coated on the top and bottom surfaces of the RFID tags, and the solvent is evaporated to obtain the final product. The cetyl alcohol and octadecyl alcohol mixture is a mixture of cetyl alcohol and octadecyl alcohol in a weight ratio of 10:3.

[0012] S2. The RFID tag is attached to each primary packaging unit by adhesive, and the passive coupling antenna is attached to each intermediate packaging unit by adhesive; each primary packaging unit, i.e., the medicine box, is filled with 25 bottles of blood products (e.g., human serum albumin) that need to be stored at 2°C to 8°C, and each intermediate packaging unit, i.e., the large medicine box, is filled with 20 primary packaging units.

[0013] S3. Use an RFID reader attached to a cold chain transport vehicle (e.g., a cold chain vehicle capable of providing blood product storage conditions of 2°C to 8°C) to collect temperature information of the blood products (e.g., human serum albumin) filled in each primary packaging unit, and store the collected information in the data storage device.

[0014] S4. Throughout the cold chain transportation of blood products (such as human serum albumin), RFID readers are used at fixed intervals (e.g., 1 hour) to collect and store the temperature information of the blood products filled in each primary packaging unit, thereby achieving full-process monitoring of the temperature of blood products during cold chain transportation.

[0015] According to the method of the first aspect of the present invention, in step S1, the suspension is uniformly coated on the upper and lower surfaces of the RFID tag, and the solvent is evaporated to obtain the coated RFID tag. The coating amount per square centimeter of tag is 1 mg to 2 mg based on magnesium aluminum silicate.

[0016] According to the method of the first aspect of the present invention, in step S1, the micronized magnesium aluminum silicate refers to magnesium aluminum silicate powder that can pass through a standard No. 8 sieve completely and contains at least 95% that can pass through a No. 9 sieve.

[0017] According to the method of the first aspect of the present invention, the RFID tag is coated with magnesium aluminum silicate and then encapsulated with a plastic film on its surface.

[0018] According to the method of the first aspect of the present invention, the blood product is selected from: human serum albumin, pH4 intravenous immunoglobulin, human fibrinogen, human coagulation factor VIII, human prothrombin complex, etc.

[0019] According to the method of the first aspect of the present invention, each of the primary packaging units is filled with 1 to 50, for example, 1 to 20, for example, 1 to 10 blood product units, and each of the intermediate packaging units is filled with 1 to 30, for example, 1 to 20, for example, 1 to 10 primary packaging units. The term "blood product unit" is a concept conventionally understood in the art, such as referring to a sealed glass vial containing a pharmaceutical preparation (e.g., a vial of human serum albumin or a vial of other blood products); the terms "primary packaging unit" and "intermediate packaging unit" are concepts conventionally understood in the art, such as referring to smaller and larger capacity pharmaceutical packaging boxes (or cartons), respectively.

[0020] According to the method of the first aspect of the present invention, the interval time is a fixed or variable interval time in the range of 1 to 24 hours, for example, a fixed or variable interval time in the range of 1 to 18 hours, for example, a fixed or variable interval time in the range of 1 to 12 hours.

[0021] As an extension of the technology of the inventors of this application, unless otherwise stated, the specific design of the RFID reader, passive coupling antenna and RFID tag involved in this invention is as described in Chinese Patent CN113283259B. The RFID reader, passive coupling antenna and RFID tag can also be designed in other ways known in the art.

[0022] According to a first aspect of the present invention, the RFID reader is radio frequency coupled to a plurality of RFID tags via the passive coupling antenna and is used to read the plurality of RFID tags simultaneously.

[0023] According to the method of the first aspect of the present invention, the RFID tag is an RFID tag with an interface and separate transmit and receive antennas.

[0024] According to the method of the first aspect of the present invention, each of the RFID tags includes a receiving antenna, an energy harvesting module, a first modulation and demodulation module, a transmitting antenna, a first interface module, and a first data storage module.

[0025] According to a first aspect of the method of the present invention, wherein in any of the RFID tags, the receiving antenna is connected to the input terminal of the energy harvesting module, and the receiving antenna is also connected to the signal input terminal of the first modem module; the output terminal of the energy harvesting module is connected to the power supply terminal of the first modem module, the signal output terminal of the first modem module is connected to the transmitting antenna, the signal output terminal of the first modem module is also connected to the input terminal of the first interface module, the output terminal of the first interface module is connected to the input terminal of the first data storage module, and the output terminal of the first data storage module is connected to the signal input terminal of the first modem module; the front ends of both the receiving antenna and the transmitting antenna are equipped with multi-stage adjustable capacitors.

[0026] According to the method of the first aspect of the present invention, the RFID tag further includes a rectifier module, and the output of the energy harvesting module is also connected to a multi-stage adjustable capacitor of the receiving antenna and the transmitting antenna through the rectifier module.

[0027] According to the method of the first aspect of the invention, the energy harvesting module has a design conventional in the art.

[0028] According to the method of the first aspect of the present invention, the receiving antenna and the transmitting antenna have different resonant points, and the Q values ​​of both the receiving antenna and the transmitting antenna are greater than 50.

[0029] According to a first aspect of the method of the present invention, the RFID tag further includes a frequency division module, and the first modulation and demodulation module is connected to the transmitting antenna through the frequency division module; the frequency division module is specifically a frequency division circuit with adjustable frequency division coefficient.

[0030] According to a first aspect of the method of the present invention, the first interface module includes any one or more combinations of an SPI interface, an IIC interface, and an ADC interface.

[0031] According to a first aspect of the method of the present invention, the first modulation and demodulation module is embedded with a hardware filtering algorithm.

[0032] According to the method of the first aspect of the present invention, the RFID reader has a conventional design pattern in the art, for example, it includes a multi-transmit antenna array, a multi-receive antenna array, a second modulation and demodulation module, a second interface module, a second data storage module, and a control module.

[0033] According to the method of the first aspect of the present invention, the operation mode of the RFID-based multi-tag radio frequency identification system is well known to those skilled in the art, for example, as detailed in CN118761702B.

[0034] According to the method of the first aspect of the present invention, the tuning process of the RFID tag is well known to those skilled in the art, for example as detailed in CN118761702B.

[0035] According to the method of the first aspect of the present invention, the tuning process of the RFID reader is well known to those skilled in the art, for example as detailed in CN118761702B.

[0036] According to the method of the first aspect of the invention, the RFID reader and passive coupling antenna may be those known in the art, such as those that are readily available from commercial sources.

[0037] According to the method of the first aspect of the present invention, the RFID tag is based on RFID tags known in the art (e.g., such RFID tags that can be obtained directly from commercial sources), and further subjected to coating treatment in the following manner: a mixture of micronized magnesium aluminum silicate, povidone K30, and a mixture of cetyl alcohol and octadecyl alcohol is mixed in a weight ratio of 3:1:1, added to 8 times its weight of ethanol, stirred and heated to 65°C to dissolve the mixture of povidone K30 and cetyl alcohol and uniformly suspend the magnesium aluminum silicate to obtain a suspension, which is then uniformly coated on the upper and lower surfaces of the RFID tag, and the solvent is evaporated to obtain a coated RFID tag; the cetyl alcohol and octadecyl alcohol mixture is a mixture of cetyl alcohol and octadecyl alcohol in a weight ratio of 10:3; further, the coating amount per square centimeter of the coated tag is 1mg to 2mg based on magnesium aluminum silicate; further, the micronized magnesium aluminum silicate refers to magnesium aluminum silicate powder that can completely pass through a standard No. 8 sieve and contains no less than 95% that can pass through a No. 9 sieve.

[0038] Furthermore, a second aspect of the present invention provides a method for surface coating of RFID tags, comprising the following steps: mixing micronized magnesium aluminum silicate, povidone K30, and a mixture of cetyl alcohol and octadecyl alcohol in a weight ratio of 3:1:1, adding the mixture to 8 times its weight of ethanol, stirring and heating to 65°C to dissolve the povidone K30 and cetyl alcohol mixture and uniformly suspend the magnesium aluminum silicate to obtain a suspension, uniformly coating the upper and lower surfaces of the RFID tag with the suspension, and evaporating the solvent to obtain the coated RFID tag; wherein the cetyl alcohol and octadecyl alcohol mixture is a mixture of cetyl alcohol and octadecyl alcohol in a weight ratio of 10:3; the coating amount per square centimeter of tag is 1mg~2mg based on magnesium aluminum silicate; wherein the micronized magnesium aluminum silicate refers to magnesium aluminum silicate powder that can completely pass through a standard No. 8 sieve and contains no less than 95% of magnesium aluminum silicate powder that can pass through a No. 9 sieve.

[0039] This invention improves the industrial applicability of RFID tags by coating them, enabling them to maintain excellent performance even when exposed to higher or lower temperature environments. This unexpected effect is achieved by using a combination of cetyl alcohol and octadecyl alcohol. Detailed Implementation

[0040] The following embodiments provided in this invention are for illustrative purposes only and are not intended to be used, nor should they be construed as limiting the invention in any way. Those skilled in the art will recognize that conventional variations and modifications can be made to the following embodiments without departing from the spirit or scope of the invention. The materials and methods used in the experiments are described generally and / or specifically in this invention. While many of the materials and methods of operation used to achieve the objectives of this invention are well known in the art, the invention is still described in as much detail as possible herein. It will be apparent to those skilled in the art that, unless otherwise stated, the materials and methods of operation used in this invention are well known in the art.

[0041] The overall architecture of the multi-tag RFID system involved in this invention includes independent RFID readers, passive coupling antennas, and RFID tags. The passive coupling antennas and RFID tags are placed within a preset space. The RFID reader is radio frequency coupled to multiple RFID tags through the passive coupling antennas and is used to read multiple RFID tags simultaneously. That is, one passive coupling antenna can be paired with multiple RFID tags to work; in addition, one RFID reader can work with multiple passive coupling antennas.

[0042] A specific example of an RFID tag is an RFID tag with an interface and separate transmit and receive antennas; the RFID reader is an RFID reader with an interface and separate transmit and receive antennas. In a multi-tag RFID system, one RFID reader communicates with multiple RFID tags simultaneously. However, the placement and angle of these tags are random, and it cannot be guaranteed that each RFID tag antenna will be parallel to the plane of the reader's RFID antenna. When the planes of the RFID tag antenna and the reader's RFID antenna are significantly non-parallel, communication will fail. To ensure that one RFID reader can communicate with multiple RFID tags simultaneously, a passive coupling antenna is used as a buffer to solve the reading direction problem. The magnetic field on the RFID reader antenna can be cut by the passive coupling antenna, generating mutual inductance current to form a new magnetic field. These new magnetic fields can couple with the RFID tag antenna at the other end, realizing communication between the reader and the tag, thereby enabling one reader to read tags in multiple different directions.

[0043] In multi-tag scenarios, the RFID tag antenna is not necessarily perfectly parallel to the plane of the RFID reader antenna. Tag reading is most difficult when the reader antenna is perfectly perpendicular to the RFID tag antenna, leading to communication failure. Furthermore, the magnetic field generated by the RFID reader cannot induce a mutual inductance current in the RFID tag antenna, thus failing to activate the RFID tag and hindering reliable communication. Introducing a passive coupling antenna allows it to act as a medium, cutting through the magnetic field on the RFID reader antenna and generating a mutual inductance current to form a new magnetic field. This newly generated magnetic field can couple with the RFID tag antenna at the other end, transmitting the information from the reader to the card.

[0044] The RFID tag antenna of the present invention includes a receiving antenna and a transmitting antenna as described in the RFID tag, and the RFID reader antenna includes a multi-transmitting antenna array and a multi-receiving antenna array as described in the RFID reader.

[0045] It is well known in the art that RFID tags, which are readily available from commercial sources, are included in an RFID tag. The RFID tag comprises a receiving antenna, an energy harvesting module, a first modulation / demodulation module, a transmitting antenna, a first interface module, and a first data storage module. The receiving antenna is connected to the input terminal of the energy harvesting module and also to the signal input terminal of the first modulation / demodulation module. The output terminal of the energy harvesting module is connected to the power supply terminal of the first modulation / demodulation module, and the signal output terminal of the first modulation / demodulation module is connected to the transmitting antenna. The signal output terminal of the first modulation / demodulation module is also connected to the input terminal of the first interface module, the output terminal of the first interface module is connected to the input terminal of the first data storage module, and the output terminal of the first data storage module is connected to the signal input terminal of the first modulation / demodulation module. Multiple adjustable capacitors are connected to the front ends of both the receiving antenna and the transmitting antenna.

[0046] In this invention, the term "RFID tag" may also be simply referred to as "tag," and the term "RFID reader" may also be simply referred to as "reader." The working principle of RFID tags is known in the art.

[0047] Furthermore, the separate uplink and downlink antennas of the RFID tag in this invention facilitate the use of high-Q circuits, greatly improving communication distance and ensuring the feasibility of reliable communication under high-Q conditions. The receiving and transmitting antennas have different resonant points and are used for the downlink and uplink communication links respectively, with the Q values ​​of both antennas greater than 50.

[0048] As is known in the art, both the transmitting and receiving antennas can be loop antennas constructed using PCB traces. For example, the front end of the antenna is equipped with a multi-stage adjustable capacitor C, that is, the front end of both the receiving and transmitting antennas is equipped with a multi-stage adjustable capacitor C, which is composed of multiple adjustable capacitors connected in parallel. The number of adjustable capacitors is set according to the actual situation.

[0049] Both the transmitting and receiving antennas can be equipped with multi-stage adjustable capacitors at their front ends for automatic fine-tuning of the Q value or resonant point. These multi-stage adjustable capacitors can, to a certain extent, ensure that the Q value or resonant point of the antenna remains constant. When the tag is placed in different environments, the capacitive or inductive effects introduced by the environment can affect the antenna's resonant point or Q value. The introduction of multi-stage adjustable capacitors can compensate for these environmental influences to some extent, thus ensuring the tag's reliable performance. Furthermore, it can ensure that the communication distance does not decrease due to changes in the Q value. When the Q value or resonant point changes due to external environmental factors, the energy absorbed from the antenna will change. Because the Q value is high, changes caused by resonance may result in a sharp reduction in absorbed energy, leading to chip malfunction. The introduction of multi-stage adjustable capacitors can mitigate this situation. Through the design of this invention, the tag can adaptively and dynamically adjust the Q value or resonant frequency of the antenna. This dynamic Q value adjustment helps the circuitry ensure higher energy harvesting efficiency and a communication distance superior to traditional RFID.

[0050] The energy harvesting module converts the high-frequency signal from the carrier wave received by the receiving antenna into a DC signal using a voltage boosting circuit composed of diodes and capacitors to power other parts (such as the first modulation and demodulation module). The energy harvesting module includes capacitors C1 to C4 and diodes D1 to D4. One end of capacitor C1 and the anode of diode D2 form the input terminal of the energy harvesting module. The other end of capacitor C1 is connected to the cathode of diode D2 and one end of capacitor C2. The other end of capacitor C2 is connected to the cathode of diode D3 and the anode of diode D4. The cathode of diode D4 is connected to one end of capacitor C4. The other end of capacitor C4 is connected to the anode of diode D3 and the cathode of diode D1. The anode of diode D1 is connected to the cathode of diode D2. One end of capacitor C3 is connected to the cathode of diode D1, and the other end of capacitor C3 is connected to the anode of diode D2. The anode of diode D2 is also connected to digital ground. The output terminal of the energy harvesting module is located between the anode of diode D2 and the cathode of diode D4. In addition, the RFID tag also includes a rectifier module, and the output of the energy harvesting module is connected to the receiving antenna and the transmitting antenna via the rectifier module through a multi-stage adjustable capacitor. When the DC signal from the energy harvesting module enters the rectifier module, its peak voltage serves as feedback for the antenna, adjusting the antenna's Q value or resonant point to achieve optimal energy harvesting efficiency. The RFID tag of this invention employs adaptive transmission frequency adjustment, changing the step coefficient to alter the transmission frequency, ensuring consistency between the transmission frequency and the resonant frequency of the transmitting antenna, thus optimizing the uplink communication distance. Furthermore, the first modulation / demodulation module is used to demodulate the signal in the carrier wave or modulate the signal to be transmitted. Specifically, the RFID tag also includes a frequency division module, and the first modulation / demodulation module is connected to the transmitting antenna via the frequency division module; the frequency division module is a frequency division circuit with an adjustable division coefficient. When the first modulation / demodulation module modulates local information for use in the uplink, the frequency division module down-converts the carrier signal, and the down-converted signal is used to offset the center frequency of the carrier signal to match the resonant frequency of the transmitting antenna, achieving optimal transmission performance. The division coefficient of the frequency divider module can be adjusted, so that when the carrier after frequency division deviates from the resonant point of the transmitting antenna, the problem can be mitigated by appropriately changing the division coefficient.

[0051] In one embodiment, the first interface module is used to connect to and communicate with external devices. It can transmit demodulated data from the downlink or information transmitted by the external device. Different interface circuits can be selected, such as SPI, IIC, and ADC. The first interface module is used to extend the tag's functionality, such as connecting analog or digital temperature sensors via the ADC and IIC interfaces for passive temperature sensing; or connecting a Flash chip via the SPI interface for event logging, etc.

[0052] In one embodiment, a hardware filtering algorithm is embedded in the first modulation and demodulation module. When the first interface module is connected to an external device (such as an external sensor) to read data, the data obtained by the sensor will inevitably be subject to various interferences and generate noise, which will inevitably affect the reliability of the read data. In order to obtain the most accurate data information possible, a hardware filtering algorithm is embedded inside the tag, which can obtain more stable data as much as possible without increasing costs or affecting the reliability of the system.

[0053] In addition, the RFID reader includes a multi-transmit antenna array, a multi-receive antenna array, a second modulation and demodulation module, a second interface module, a second data storage module, and a control module. The multi-receive antenna array is connected to the signal input terminal of the second modulation and demodulation module, the signal output terminal of the second modulation and demodulation module is connected to the multi-transmit antenna array, the signal output terminal of the second modulation and demodulation module is also connected to the input terminal of the second interface module, the output terminal of the second interface module is connected to the input terminal of the second data storage module, the output terminal of the second data storage module is connected to the signal input terminal of the second modulation and demodulation module, and the control module is bidirectionally connected to the second interface module. The front end of the multi-receive antenna array is equipped with a multi-stage adjustable capacitor.

[0054] The basic functional modules of an RFID reader are similar to those of the aforementioned tags, employing separate transmit and receive antenna technology and high-Q circuitry, with adjustable capacitors at the antenna end for tuning. The difference lies in the fact that, since RFID readers are active devices, beamforming technology can be incorporated at both the transmit and receive ends to improve the signal's signal-to-noise ratio (SNR), effectively increasing the communication distance. Furthermore, the introduction of multi-antenna technology helps address the directional issues of reading. For example, when a multi-receiver antenna array includes two square antennas arranged perpendicularly to each other, blind spots are rare regardless of how the RFID tag appears in the field of view. Introducing more antennas makes multi-angle RFID tag reading very easy, greatly expanding the application scenarios of RFID tags. For instance, RFID tags can be used to achieve real-time temperature collection and monitoring of multiple vaccine vials within cold chain transport vehicles or containers, thus supporting multi-card reading.

[0055] In one embodiment, the control module can specifically be a programmable control chip, which serves as the control center of the RFID reader.

[0056] The RFID-based multi-tag radio frequency identification system of this invention is used for multi-tag radio frequency identification, for example, for temperature monitoring in the cold chain transportation of pharmaceuticals, especially biological products such as blood products, especially human serum albumin. It includes the following steps.

[0057] S1. When the RFID reader detects a change in the impedance of the RFID tag, and before the RFID reader issues an inventory command, the RFID tag and the RFID reader are tuned.

[0058] S2. After the tuning between the RFID tag and the RFID reader is completed, data transmission is performed between the RFID tag and the RFID reader based on the load modulation method of full-duplex communication;

[0059] In S1,

[0060] The tuning process for RFID tags is as follows:

[0061] Adjust the multi-stage adjustable capacitor at the front end of the receiving antenna to maximize the feedback voltage of the receiving antenna;

[0062] Based on the signal strength read by the RFID reader as the feedback value, the transmitting antenna is tuned by adjusting the multi-stage adjustable capacitor at the front end of the transmitting antenna to achieve the optimal matching point.

[0063] The tuning process for an RFID reader is as follows:

[0064] Based on the ALOHA algorithm, the extreme value of the signal strength received by the multi-receiver antenna array is used as the target value for tuning. The energy of the carrier signal generated by the RFID reader is gradually increased from low to high in multiple stages. When any RFID tag among the multiple RFID tags completes its own tuning at the corresponding energy, it enters a silent state until all the RFID tags have completed tuning.

[0065] In the multi-tag RFID method, when the RFID reader detects a change in the impedance of the RFID tag, and before the RFID reader issues an inventory command, the RFID tag and the RFID reader are tuned to ensure normal and stable communication between them. In addition, using full-duplex communication can reduce feedback time.

[0066] This invention utilizes a traditional RFID protocol. When the RFID reader detects a change in impedance, it issues an inventory command to begin reading the card. Furthermore, before inventorying, this invention performs an automatic adjustment of the Q value or resonant frequency. For the tag, the receiving antenna automatically adjusts its capacitance to maximize the feedback voltage, achieving resonance. The transmitting antenna tuning requires the cooperation of the RFID reader; whether the transmitting end has reached the optimal matching point is determined by the RFID reader's feedback information. Specifically, the RFID reader sends the received signal strength back to the tag as a feedback value. For the RFID reader, only the receiving end needs tuning: the extreme value of the received signal strength is used as the tuning target value. Since tuning is for mismatched circuits (i.e., the carrier frequency deviates from the resonant point), and the tag in this invention uses a high-Q circuit, when the circuit becomes mismatched, the high Q value may cause the resonant point to deviate too far, resulting in insufficient energy at the receiving end of the circuit, rendering it inoperable. Therefore, during the tuning process, the energy of the carrier signal generated by the RFID reader increases progressively from low to high in several stages. Once a tag has completed its own tuning under certain energy conditions, it can remain silent and no longer participate in the tuning process. The entire tuning process is completed in conjunction with the ALOHA algorithm to calibrate multiple tags; the entire calibration process is completed in a very short time; if necessary, such as when tag position changes cause antenna detuning, manual re-tuning can be performed. In the tuning method between the tag and the RFID reader, when the RFID reader detects a change in the RFID tag's impedance, and before the RFID reader issues an inventory command, tuning is performed between the RFID tag and the RFID reader to ensure normal and stable communication between them.

[0067] In step S2 of the method of the present invention, the load modulation method for full-duplex communication specifically involves the following: the downlink between the RFID tag and the RFID reader uses amplitude modulation, and the uplink between the RFID tag and the RFID reader uses phase modulation. The method for implementing amplitude modulation in the downlink and phase modulation in the uplink between the tag and the reader is as follows: the real part of the impedance of the load element and the real part of the impedance of the load modulation element are set to correspond in both magnitude and sign, and the imaginary part of the impedance of the load element and the imaginary part of the impedance of the load modulation element are set to correspond in both magnitude and sign.

[0068] This invention employs amplitude modulation for the downlink and phase modulation for the uplink.

[0069] Example 1:

[0070] This embodiment is specifically based on the embodiment described in CN118761702B, and the steps are as follows:

[0071] Take an adhesive RFID tag and pre-coat the tag surface with a magnesium aluminum silicate coating. The magnesium aluminum silicate coating is applied as follows: micronized magnesium aluminum silicate, povidone K30, and lanolin are mixed in a weight ratio of 3:1:1, added to 8 times their weight of ethanol, stirred, and heated to 65°C to dissolve the povidone K30 and lanolin and uniformly suspend the magnesium aluminum silicate to obtain a suspension. The suspension is then uniformly coated on the top and bottom surfaces of the RFID tag. The solvent is evaporated to obtain the RFID tag used in this embodiment. A plastic film is further encapsulated on the surface. The coating amount per square centimeter of tag is 1.5 mg based on magnesium aluminum silicate. In the context of this invention, micronized magnesium aluminum silicate refers to magnesium aluminum silicate powder that can pass through a standard No. 8 sieve and contains no less than 95% that can pass through a No. 9 sieve.

[0072] Monitor the temperature of blood products (human serum albumin, 2g / bottle, 20%, 10ml) during cold chain transportation using the following steps:

[0073] S1. A multi-tag radio frequency identification system based on RFID is provided, which includes an independent RFID reader as described above in this invention, multiple passive coupling antennas, and multiple RFID tags as described in this embodiment, wherein the RFID reader is provided with a data storage device.

[0074] S2. The RFID tag is fixed on each primary packaging unit (by adhesive), and the passive coupling antenna is fixed on each intermediate packaging unit (by adhesive); each primary packaging unit, i.e., the medicine box, is filled with 25 bottles of human serum albumin that need to be stored at 2°C to 8°C, and each intermediate packaging unit, i.e., the large medicine box, is filled with 20 primary packaging units.

[0075] S3. Use an RFID reader attached to a cold chain transport vehicle (a cold chain vehicle capable of providing blood product preservation conditions of 2°C to 8°C) to collect temperature information of the blood products filled in each primary packaging unit, and store the collected information in the data storage device;

[0076] S4. Throughout the cold chain transportation of blood products, RFID readers are used at fixed intervals (1 hour) to collect and store the temperature information of the blood products filled in each primary packaging unit, thereby achieving full-process monitoring of the temperature of blood products during cold chain transportation.

[0077] As described in CN118761702B, after the RFID tags are treated with the magnesium aluminum silicate coating as described herein, the uniformity of the temperature data returned by the 20 primary packaging units with RFID tags in the same intermediate packaging unit is significantly improved.

[0078] It is known that after these RFID tags undergo the above coating treatment, due to the needs of production, storage, and usage scenarios, their usage scenarios may require exposure to a fairly wide temperature range, such as from -35°C to 35°C, and even to lower and higher temperatures, such as -70°C and 60°C. This wide exposure temperature range may affect the performance of the RFID tags. The inventors have discovered that the RFID tags prepared by the magnesium aluminum silicate-povidone K30-lanolin system coating treatment in Example 1 of this invention have unsatisfactory performance problems when subjected to endurance tests or stability tests over a wide exposure temperature range, as specifically described in Experimental Example 1 of this paper.

[0079] Test Example 1: Label Durability Test

[0080] The labels obtained in Example 1 of this invention were placed at -35°C for 5 days, then at 35°C for 5 days, and this cycle was repeated 3 times to complete the sample treatment for endurance testing. Twenty labels a (that underwent the aforementioned endurance test treatment) and 20 labels b (that did not undergo the aforementioned endurance test treatment) were placed in a constant temperature environment of -10.0±0.2°C for 1 hour, and temperature data were collected. The mean temperature and SD recorded for both types of labels were calculated. The result for label a was -7.46±1.13°C (n=20), and the result for label b was -10.17±0.19°C (n=20). This result shows that the performance of the labels obtained in Example 1 of this invention significantly decreased after endurance testing, regardless of the accuracy or volatility of the test results, which is completely undesirable.

[0081] Example 2:

[0082] This embodiment refers to the method of Embodiment 1 above for label surface coating: Take an adhesive RFID tag, and pre-coat the label surface with a magnesium aluminum silicate coating. The magnesium aluminum silicate coating is applied in the following manner: Micronized magnesium aluminum silicate, povidone K30 and cetyl alcohol are mixed in a weight ratio of 3:1:1, added to 8 times the weight of ethanol, stirred and heated to 65°C to dissolve the povidone K30 and cetyl alcohol and uniformly suspend the magnesium aluminum silicate to obtain a suspension. The suspension is uniformly coated on the upper and lower surfaces of the RFID tag, and the solvent is evaporated to obtain the RFID tag used in this embodiment. A plastic film is further encapsulated on the surface. The coating amount per square centimeter of the tag is 1.5 mg based on magnesium aluminum silicate. Next, following the label durability test method of Test Example 1 of this invention, the labels obtained in this embodiment were tested after undergoing durability testing on label a and label b without durability testing treatment. Temperature data were collected at a constant temperature environment of -10.0±0.2°C. The results for label a were -9.84±0.67°C (n=20), and for label b were -10.03±0.15°C (n=20). This result indicates that the labels obtained in this embodiment, after undergoing durability testing, show significantly higher accuracy in test results compared to the product of Example 1; however, the volatility of the results still needs improvement.

[0083] Example 3:

[0084] This embodiment refers to the method of Embodiment 1 above for coating the label surface: Take an adhesive RFID tag, and pre-coat the label surface with a magnesium aluminum silicate coating. The magnesium aluminum silicate coating is applied in the following manner: Micronized magnesium aluminum silicate, povidone K30 and octadecyl alcohol are mixed in a weight ratio of 3:1:1, added to 8 times the weight of ethanol, stirred and heated to 65°C to dissolve povidone K30 and octadecyl alcohol and uniformly suspend magnesium aluminum silicate to obtain a suspension. The suspension is uniformly coated on the upper and lower surfaces of the RFID tag, and the solvent is evaporated to obtain the RFID tag used in this embodiment. A plastic film is further encapsulated on the surface. The coating amount per square centimeter of the tag is 1.5 mg based on magnesium aluminum silicate. Next, following the label durability test method of Test Example 1 of this invention, the labels obtained in this embodiment were tested after undergoing durability testing on label a and label b without durability testing treatment. Temperature data were collected at a constant temperature environment of -10.0±0.2°C. The results for label a were -9.96±0.82°C (n=20), and for label b were -9.98±0.13°C (n=20). This result indicates that the labels obtained in this embodiment, after undergoing durability testing, show significantly higher accuracy in test results compared to the product of Example 1; however, the volatility of the results still needs improvement.

[0085] The magnesium aluminum silicate, povidone K30, lanolin, cetyl alcohol, and octadecyl alcohol used in this invention are all known in the art and readily available on the market. Their CAS registration numbers are as follows: magnesium aluminum silicate CAS registration number 12511-31-8, povidone K30 CAS registration number 9003-39-8, lanolin CAS registration number 8006-54-0, cetyl alcohol CAS registration number 36653-82-4, and octadecyl alcohol CAS registration number 112-92-5.

[0086] Example 4:

[0087] This embodiment refers to the method of Embodiment 1 above for label surface coating: Take an adhesive RFID tag, and pre-coat the tag surface with a magnesium aluminum silicate coating. The magnesium aluminum silicate coating is applied as follows: Micronized magnesium aluminum silicate, povidone K30, and a mixture of cetyl alcohol and octadecyl alcohol are mixed in a weight ratio of 3:1:1, added to 8 times their weight of ethanol, stirred, and heated to 65°C to dissolve the povidone K30 and cetyl alcohol mixture and uniformly suspend the magnesium aluminum silicate to obtain a suspension. This suspension is uniformly coated on the top and bottom surfaces of the RFID tag, and the solvent is evaporated to obtain the RFID tag used in this embodiment. A plastic film is further sealed on the surface. The coating amount per square centimeter of tag is 1.5 mg based on magnesium aluminum silicate. The cetyl alcohol and octadecyl alcohol mixture is a mixture of cetyl alcohol and octadecyl alcohol in a weight ratio of 10:3. Next, following the label durability test method of Test Example 1 of this invention, the labels obtained in this embodiment were tested after undergoing durability testing on label a and label b, respectively, at a constant temperature environment of -10.0±0.2°C. The results were -10.25±0.22°C for label a (n=20) and -9.94±0.17°C for label b (n=20). This result indicates that the accuracy and volatility of the test results obtained by the labels in this embodiment after undergoing durability testing are significantly better than those of the product in Example 1.

[0088] Example 5:

[0089] This embodiment refers to the method of Embodiment 1 above for label surface coating: Take an adhesive RFID tag, and pre-coat the tag surface with a magnesium aluminum silicate coating. The magnesium aluminum silicate coating is applied as follows: Micronized magnesium aluminum silicate, povidone K30, and a mixture of hexadecyl alcohol and octadecyl alcohol are mixed in a weight ratio of 3:1:1, added to 8 times their weight of ethanol, stirred, and heated to 65°C to dissolve the povidone K30 and hexadecyl alcohol mixture and uniformly suspend the magnesium aluminum silicate to obtain a suspension. This suspension is uniformly coated on the top and bottom surfaces of the RFID tag, and the solvent is evaporated to obtain the RFID tag used in this embodiment. A plastic film is further sealed on the surface. The coating amount per square centimeter of tag is 1.5 mg based on magnesium aluminum silicate. The hexadecyl alcohol and octadecyl alcohol mixture is a mixture of hexadecyl alcohol and octadecyl alcohol in a weight ratio of 10:2. Next, following the label durability test method of Test Example 1 of this invention, the labels obtained in this embodiment were tested after undergoing durability testing on label a and label b, respectively, at a constant temperature environment of -10.0±0.2°C. The results were -10.04±0.38°C for label a (n=20) and -9.94±0.12°C for label b (n=20). This result indicates that the accuracy and volatility of the test results obtained in this embodiment after undergoing durability testing are significantly better than those of the product in Example 1, but the volatility is worse than that of Example 4.

[0090] Example 6:

[0091] This embodiment refers to the method of Embodiment 1 above for label surface coating: Take an adhesive RFID tag, and pre-coat the tag surface with a magnesium aluminum silicate coating. The magnesium aluminum silicate coating is applied as follows: Micronized magnesium aluminum silicate, povidone K30, and a mixture of cetyl alcohol and octadecyl alcohol are mixed in a weight ratio of 3:1:1, added to 8 times their weight of ethanol, stirred, and heated to 65°C to dissolve the povidone K30 and cetyl alcohol mixture and uniformly suspend the magnesium aluminum silicate to obtain a suspension. This suspension is uniformly coated on the top and bottom surfaces of the RFID tag, and the solvent is evaporated to obtain the RFID tag used in this embodiment. A plastic film is further sealed on the surface. The coating amount per square centimeter of tag is 1.5 mg based on magnesium aluminum silicate. The cetyl alcohol and octadecyl alcohol mixture is a mixture of cetyl alcohol and octadecyl alcohol in a weight ratio of 10:4. Next, following the label durability test method of Test Example 1 of this invention, the labels obtained in this embodiment were tested after undergoing durability testing on label a and label b, respectively, at a constant temperature environment of -10.0±0.2°C. The results were -9.94±0.51°C for label a (n=20) and -10.02±0.18°C for label b (n=20). This result indicates that the accuracy and volatility of the test results obtained by the labels in this embodiment after undergoing durability testing are significantly better than those of the product in Example 1, but the volatility is worse than that of Example 4.

[0092] The results above show that the labels coated with a 10:3 mixture of cetyl alcohol and octadecyl alcohol exhibit significantly better durability test performance.

[0093] Example 7: Application of Labels

[0094] As described in steps S1 to S4 of Example 1 of this document, the tag application test was conducted as follows: The test sample consisted of an intermediate packaging unit (with a passive coupling antenna fixed to it), and 20 primary packaging units (human serum albumin, 2g / bottle, 20%, 10ml) filled within the intermediate packaging unit, each primary packaging unit affixed with an RFID tag. The test sample was transferred from a constant room temperature environment to a cold storage room with a predetermined temperature of -1°C to 1°C. Temperature data was collected at 0 hours, 1 hour, 2 hours, 4 hours, 6 hours, 9 hours, and 12 hours. For these seven reading time points, the result at each reading time point is expressed as the mean ± SD of the 20 readings. The tags obtained in Examples 1 and 4 were tested.

[0095] The results of the label obtained in Example 1 without undergoing the endurance test treatment in Example 1 (label b) are as follows: 0h=24.25±0.13°C, 1h=8.02±0.21°C, 2h=-1.07±0.16°C, 4h=-0.38±0.15°C, 6h=-0.14±0.20°C, 9h=0.53±0.18°C, 12h=-0.18±0.19°C. This indicates that the accuracy and volatility of the results obtained from the label without endurance test treatment are excellent.

[0096] The results of the label obtained in Example 1 after undergoing the endurance test treatment (label a) are as follows: 0h=25.33±1.33°C, 1h=11.25±1.08°C, 2h=2.34±0.84°C, 4h=1.17±0.93°C, 6h=2.42±0.87°C, 9h=2.13±0.97°C, 12h=1.85±0.79°C. This indicates that the accuracy and volatility of the results obtained from the label after the endurance test treatment are not satisfactory.

[0097] The results of the label obtained in Example 4, which did not undergo the endurance test treatment in Example 1 (label b), are as follows: 0h=25.16±0.19°C, 1h=8.35±0.16°C, 2h=-1.13±0.21°C, 4h=-0.53±0.15°C, 6h=-0.24±0.22°C, 9h=0.16±0.13°C, 12h=-0.22±0.17°C. This indicates that the accuracy and stability of the results obtained from the label without endurance test treatment are excellent.

[0098] The results of the label obtained in Example 4 after undergoing the endurance test treatment in Example 1 (label a) are as follows: 0h=24.57±0.27°C, 1h=8.92±0.22°C, 2h=-0.85±0.14°C, 4h=0.13±0.17°C, 6h=-0.18±0.12°C, 9h=0.21±0.24°C, 12h=-0.15±0.14°C. This shows that even after undergoing the endurance test treatment, the accuracy and volatility of the results obtained by the label are still quite good.

[0099] The above results show that the label provided by the present invention still exhibits excellent stability even after undergoing endurance testing. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for monitoring the temperature of blood products transported in a cold chain, characterized in that, Includes the following steps: S1. A multi-tag radio frequency identification system based on RFID is provided, comprising independent RFID readers, multiple passive coupling antennas, and multiple RFID tags. The RFID readers are equipped with data storage. The RFID tags are coated with a magnesium aluminum silicate coating on their surface in the following manner: micronized magnesium aluminum silicate, povidone K30, and a mixture of cetyl alcohol and octadecyl alcohol are mixed in a weight ratio of 3:1:1, added to 8 times their weight of ethanol, stirred, and heated to 65°C to dissolve the povidone K30 and cetyl alcohol mixture and uniformly suspend the magnesium aluminum silicate to obtain a suspension. This suspension is then uniformly coated on the top and bottom surfaces of the RFID tags, and the solvent is evaporated to obtain the final product. The cetyl alcohol and octadecyl alcohol mixture is a mixture of cetyl alcohol and octadecyl alcohol in a weight ratio of 10:

3. S2. The RFID tag is fixed to each primary packaging unit by adhesive, and the passive coupling antenna is fixed to each intermediate packaging unit by adhesive; each primary packaging unit, i.e., the medicine box, is filled with 25 bottles of blood products that need to be stored at 2°C to 8°C, and each intermediate packaging unit, i.e., the large medicine box, is filled with 20 primary packaging units. S3. Use an RFID reader attached to the cold chain transport vehicle to collect temperature information of the blood products filled in each primary packaging unit, and store the collected information in the data storage device; S4. Throughout the cold chain transportation of blood products, RFID readers are used at fixed intervals to collect and store the temperature information of the blood products filled in each primary packaging unit, thereby achieving full-process monitoring of the temperature of blood products during cold chain transportation.

2. The method for monitoring the temperature of blood products transported in the cold chain according to claim 1, characterized in that, In step S1, the suspension is evenly coated on the top and bottom surfaces of the RFID tag, and the solvent is evaporated to obtain the coated RFID tag. The coating amount per square centimeter of tag is 1mg~2mg based on magnesium aluminum silicate.

3. The method for monitoring the temperature of blood products transported in the cold chain according to claim 1, characterized in that, In step S1, the micronized magnesium aluminum silicate refers to magnesium aluminum silicate powder that can pass through a standard No. 8 sieve completely and contains no less than 95% that can pass through a No. 9 sieve.

4. The method for monitoring the temperature of blood products transported in the cold chain according to claim 1, characterized in that, The RFID tag was coated with magnesium aluminum silicate and then sealed with a plastic film.

5. The method for monitoring the temperature of blood products transported in the cold chain according to claim 1, characterized in that, The blood products are selected from: human serum albumin, pH4 type intravenous human immunoglobulin, human fibrinogen, human coagulation factor VIII, and human prothrombin complex.

6. A method for monitoring the temperature of blood products transported in a cold chain according to claim 1, characterized in that, The cold chain transport vehicle is a refrigerated truck capable of providing blood product preservation conditions at 2°C to 8°C.

7. The method for monitoring the temperature of blood products transported in the cold chain according to claim 1, characterized in that, Each of the primary packaging units contains 1 to 50 blood product units.

8. The method for monitoring the temperature of blood products transported in the cold chain according to claim 1, characterized in that, Each of the intermediate packaging units contains 1 to 30 primary packaging units.

9. The method for monitoring the temperature of blood products transported in the cold chain according to claim 1, characterized in that, The interval is a fixed or variable interval within the range of 1 to 24 hours.

10. A method for monitoring the temperature of blood products transported in a cold chain according to claim 1, characterized in that, The interval is a fixed or variable interval within the range of 1 to 12 hours.