A closed-loop control system, method, electronic equipment and medium for a medical heat sealing machine

Abstract

The present invention relates to a closed-loop control system, method, device, and medium for a medical heat sealer. The system comprises a power amplifier that generates a high-frequency signal, which is coupled via a dual-directional coupler to produce a low-power radio frequency signal and a main signal. An impedance matching network is used to match the impedance of a heat sealer head. The low-power radio frequency signal is attenuated by an attenuator. A power meter detects the attenuated signal, obtains forward power and reflected power, and feeds these back to a main controller. The main controller adjusts the power amplifier based on the forward power and reflected power, calculates return loss, and switches the impedance matching network via a radio frequency switch. The system can detect the output power of the power amplifier and form a closed-loop control loop to ensure stable output of the power amplifier. The system can monitor reflected power in real time. When reflected power is excessive, the system switches the impedance matching circuit to reduce reflected power, protect the circuit, and increase heat-sealing power. The system can also detect no-load conditions and pipeline damage and leakage, terminating heat sealing when a fault occurs, thereby ensuring system safety.

Description

Technical Field

[0001] The present invention relates to the field of high-frequency heat sealing technology, and in particular to a closed-loop control system, method, electronic equipment and medium for a medical heat sealing machine. Background Art

[0002] The high-frequency heat sealer is an ideal sealing machine for disposable plastic bag infusion tubes commonly used in the medical industry. It generates high-frequency energy, such as 40.68MHz, in the form of an alternating electromagnetic field, and transmits it to the mold and fixed electrode that clamp the PVC infusion tube. Under the action of the alternating electromagnetic field, the PVC material molecules vibrate and rub at this frequency, causing them to heat up and soften. At this time, applying pressure to the tube will cause it to bond together.

[0003] The high-frequency power generator is the core component. A crystal oscillator is often used to generate a high-frequency oscillation signal, which is then used to generate a high-power high-frequency signal through a power amplifier circuit. Its output impedance is 50Ω. The heat seal head acts as the system's load. Matching it to 50Ω can achieve maximum power. Impedance mismatch will affect the output power of the power amplifier board, and the resulting signal reflection will also damage the components of the power amplifier board. Therefore, impedance matching of the load is crucial, and measuring the reflected power is an important basis for determining whether the match is accurate (if matched to the standard impedance, no reflected power will be generated in the circuit). When the PVC infusion tube softens due to oscillation, friction, heat, and heat, its relative dielectric constant decreases. As the mold is pushed toward the fixed plate, applying pressure to the PVC infusion tube, the distance between the mold and the plate decreases, causing the entire load impedance to change. Load changes cause the impedance matching circuit to become unbalanced, deviating from the standard 50Ω load. This causes changes in the amplifier's output power and reflected power. Reduced output power can lead to thermal sealing failure, while excessive output power can damage the circuit. Increased reflected power can also degrade the thermal sealing effect, while excessive reflected power can also damage the circuit. Furthermore, as components age, their power can become unstable. Therefore, load impedance matching and high-frequency power detection are crucial for ensuring thermal sealing system reliability. Summary of the Invention

[0004] In order to achieve the above-mentioned purpose and other advantages of the present invention, the first purpose of the present invention is to provide a closed-loop control system for a medical heat sealer, comprising a main controller, a power amplifier, an active crystal oscillator, a dual directional coupler, an impedance matching network, a radio frequency switch, an attenuator, and a power meter; wherein,

[0005] The active crystal oscillator is connected to the power amplifier to generate a high-frequency signal;

[0006] The high-frequency signal is coupled to a low-power radio frequency signal through the dual-directional coupler;

[0007] The output port of the dual directional coupler outputs the main signal to the impedance matching network;

[0008] The impedance matching network is used to match the impedance of the heat sealing head;

[0009] The low-power radio frequency signal is attenuated by the attenuator;

[0010] The power meter detects the attenuated signal to obtain forward power and reflected power, and feeds the forward power and reflected power back to the main controller;

[0011] The main controller adjusts the power amplifier according to the forward power and the reflected power, calculates the return loss, and switches the impedance matching network through the radio frequency switch.

[0012] Furthermore, a filter is included, and the high-frequency signal is filtered by the filter and then transmitted to the dual directional coupler.

[0013] Furthermore, the load change during the heat sealing process is the capacitance change caused by the decrease in the inter-electrode spacing of the heat sealing head. The capacitance calculation formula of the heat sealing head is:

[0014]

[0015] Among them, ε is the dielectric constant, S is the area facing the plates, k is the electrostatic force constant, and d is the distance between the plates.

[0016] Furthermore, the impedance matching network uses series-parallel inductance to offset the impedance mismatch caused by the capacitance change of the heat sealing head.

[0017] Furthermore, the impedance matching network is a T-shaped matching circuit matrix with series-parallel inductance increasing in sequence by m*n; wherein m is the number of columns of the matching circuit matrix, and n is the number of rows of the matching circuit matrix.

[0018] Furthermore, the calculation formula of the return loss is:

[0019]

[0020] Among them, P i is the input power, P r is the reflected power and RL is the return loss.

[0021] Furthermore, when the return loss reaches a first preset value, it is determined that the line is damaged or unloaded, resulting in a short circuit of the heat sealing head electrodes, and the heat sealing is stopped.

[0022] Furthermore, the first preset value is 0.3dB.

[0023] Furthermore, when the return loss is less than a second preset value, the main controller generates an interrupt and switches the T-shaped matching circuit in the T-shaped matching circuit matrix through the radio frequency switch to match the thermal bonding head with a changed capacitance.

[0024] Furthermore, the second preset value is 9.5dB.

[0025] Furthermore, the T-shaped matching circuit includes a capacitor, a first inductor, and a second inductor, one end of the first inductor is connected to the capacitor, the other end of the first inductor is connected to one end of the second inductor, and the other end of the second inductor is grounded.

[0026] A second object of the present invention is to provide a closed-loop control method for a medical heat sealer of the above-mentioned system, comprising the following steps:

[0027] Determining whether the return loss is less than a first preset value;

[0028] If the return loss is less than a first preset value, it is determined that the line is damaged or unloaded, resulting in a short circuit of the heat sealing head electrodes, and the heat sealing is stopped;

[0029] If the return loss is not less than the first preset value, continue heat sealing;

[0030] If the return loss is less than a second preset value, switching the impedance matching network through the radio frequency switch;

[0031] Determining again whether the return loss is less than a second preset value;

[0032] If the return loss is less than the second preset value, the process jumps to the step of switching the impedance matching network through the radio frequency switch and continues to execute if the return loss is less than the second preset value;

[0033] If the return loss is not less than a second preset value for a preset time, it is determined that the heat sealing system is stable and the heat sealing is terminated.

[0034] Furthermore, before jumping to the step of switching the impedance matching network through the radio frequency switch if the return loss is less than the second preset value, the method further includes the following steps:

[0035] If the return loss is less than the second preset value, determining again whether the return loss is less than the first preset value;

[0036] If the return loss is less than a first preset value, it is determined that the pipeline is damaged and leaking, causing the heat sealing head electrodes to be short-circuited, and the heat sealing is stopped;

[0037] If the return loss is not less than the first preset value, the process jumps to the step of switching the impedance matching network through the radio frequency switch if the return loss is less than the second preset value and continues to execute.

[0038] Furthermore, the impedance matching network is a T-shaped matching circuit matrix, and obtaining the T-shaped matching circuit matrix includes the following steps:

[0039] Obtaining the measured impedance of the heat sealing head at different distances between the plates of the heat sealing head;

[0040] The parameters of the T-shaped matching circuit are adjusted on the Smith chart so that the impedance of the heat sealing head is within a preset range of the standard load at different distances between the plates of the heat sealing head, and the return loss is greater than a second preset value at different distances between the plates of the heat sealing head during the entire heat sealing process, thereby obtaining a T-shaped matching circuit matrix.

[0041] The third object of the present invention is to provide an electronic device comprising: a memory on which program code is stored; a processor connected to the memory, and when the program code is executed by the processor, a method for recognizing wrist fracture rehabilitation training movements is implemented.

[0042] A fourth object of the present invention is to provide a computer-readable storage medium having program instructions stored thereon, which implement a method for recognizing wrist fracture rehabilitation training movements when the program instructions are executed.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention provides a closed-loop control system, method, electronic equipment and medium for a medical heat sealing machine. A through-type power meter is added between a high-frequency heat sealing machine power generator and a heat sealing head load to detect a coupling signal, thereby monitoring power changes, and an impedance matching network is added to perform impedance matching. The through-type power meter can monitor the output power of a power amplifier, and a negative feedback system is used to ensure stable output of the heat sealing power. The reflected power is monitored, and an impedance matching circuit is switched by a radio frequency switch to reduce the reflected power, thereby ensuring the safety and stability of the heat sealing system and improving the heat sealing power.

[0045] The present invention adopts a through-type power meter, which can detect the output power of the power amplifier and form a closed-loop control to ensure the stable output of the power amplifier; it can monitor the reflected power in real time, and when the reflected power is too large, it switches the impedance matching circuit to reduce the reflected power, protect the circuit, and improve the thermal synthesis power; it can realize the judgment of no-load and pipeline damage and leakage, and terminate the thermal sealing when a fault occurs, protect the circuit, and ensure the safety of the system.

[0046] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the description, the following preferred embodiments of the present invention are described in detail with reference to the accompanying drawings. The specific implementation methods of the present invention are given in detail by the following embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0048] Figure 1 Schematic diagram of a closed-loop control system for a medical heat sealing machine according to Example 1;

[0049] Figure 2 Schematic diagram of the matching circuit matrix of Example 1;

[0050] Figure 3 Schematic diagram of a T-shaped matching circuit in Example 1;

[0051] Figure 4 This is a flow chart of the closed-loop control method for a medical heat sealer according to Example 2;

[0052] Figure 5 This is a schematic diagram of an electronic device according to Example 3;

[0053] Figure 6 Schematic diagram of the storage medium of Example 4. DETAILED DESCRIPTION

[0054] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0055] Example 1

[0056] A closed-loop control system for a medical heat sealer, including closed-loop control of a high-frequency heat seal power amplifier circuit and a closed-loop control of a load impedance matching network. The system mainly uses a power detection device to monitor the output power of the power amplifier board to adjust the power and improve system stability. It also monitors the reflected power to switch the impedance matching circuit, reduce the reflected power, and protect the circuit. Figure 1 As shown, the system includes a main controller, a power amplifier, a filter, an active crystal oscillator, a dual directional coupler, an impedance matching network, a radio frequency switch, an attenuator, and a power meter; wherein,

[0057] The active crystal oscillator is connected to the power amplifier to generate a high-frequency signal; the active crystal oscillator makes the system frequency more stable.

[0058] The high-frequency signal is filtered by the filter and then transmitted to the dual directional coupler;

[0059] The filtered high-frequency signal is coupled out as a low-power radio frequency signal through a dual directional coupler;

[0060] The output port of the dual directional coupler outputs the main signal to the impedance matching network;

[0061] The impedance matching network is used to match the impedance of the heat sealing head;

[0062] Low-power RF signals are attenuated by the attenuator;

[0063] The power meter detects the attenuated signal, obtains the forward power and reflected power, and feeds the forward power and reflected power back to the main controller;

[0064] The main controller adjusts the power amplifier according to the forward power and reflected power, calculates the return loss, and switches the impedance matching network through the RF switch.

[0065] The load change during the heat sealing process is mainly due to the capacitance change caused by the decrease in the distance between the electrodes of the heat sealing head. The capacitance calculation formula of the heat sealing head is:

[0066]

[0067] Among them, ε is the dielectric constant, S is the area facing the plates, k is the electrostatic force constant, and d is the distance between the plates.

[0068] Because the change in dielectric constant ε due to the temperature increase of the pipe being heat-sealed is small, while the change in d is large, the capacitance and reactance increase during the heat-sealing process. The impedance matching network uses series-parallel inductors to offset the impedance mismatch caused by the capacitance change of the heat-sealing head.

[0069] The impedance matching network is a T-shaped matching circuit matrix with series-parallel inductance increasing in sequence by m*n; where m is the number of columns of the matching circuit matrix and n is the number of rows of the matching circuit matrix. Figure 2 As shown, the impedance matching network of this embodiment is a 1*6 T-shaped matching circuit matrix.

[0070] like Figure 3 As shown, the T-shaped matching circuit includes a capacitor C11, a first inductor L2, and a second inductor L4. One end of the first inductor is connected to the capacitor, the other end of the first inductor is connected to one end of the second inductor, and the other end of the second inductor is grounded GND.

[0071] According to the change in the distance between the upper and lower plates during the heat sealing process, the impedance of the heat sealing head at different distances was measured. A T-shaped matching circuit was added and the parameters were adjusted on the Smith chart so that its impedance at different distances was close to the standard load of 50Ω. The reflection coefficient at different distances during the entire heat sealing process was less than 1 / 3, and finally the impedance matching network matrix was obtained.

[0072] The formula for calculating return loss is:

[0073]

[0074] Among them, P i is the input power, Pr is the reflected power and RL is the return loss.

[0075] The impedance matching network matrix is ​​connected to the load circuit and switched via an RF switch. It's impossible to achieve a perfect reflection coefficient of zero after impedance matching; generally, it's desirable for the absolute value of the reflection coefficient to be less than 1 / 3, with a return loss of approximately 9.5dB. Therefore, during the heat-sealing process, when the return loss is less than 9.5dB, the RF switch sequentially switches from impedance matching circuit 1 to impedance matching circuit 6 to match the changing load, reducing the reflected power of the heat-sealing system and protecting the circuit.

[0076] No-load or line damage will lead to infinite impedance and total reflection of the signal; pipeline damage and leakage will cause the heat sealing head electrodes to short-circuit, resulting in total reflection of the power. Therefore, at the beginning of heat sealing, if the return loss is less than 0.3dB, it is considered that there is no-load or line damage (taking into account the error in detection, the return loss threshold is set to 0.3dB), and the heat sealing should be abandoned in time to protect the short circuit. That is, when the return loss reaches the first preset value, it is determined that the line is damaged or no-load, causing the heat sealing head electrodes to short-circuit, and the heat sealing is stopped. The first preset value is 95% to 100%. In this embodiment, the first preset value is set to 0.3dB.

[0077] During the heat sealing process, if the return loss falls below 9.5dB, the main controller generates an interrupt and switches the impedance matching circuit. If the return loss falls below 0.3dB, it is determined that damage to the pipeline, such as leakage, has caused a short circuit between the mold and the fixed plate, and the heat sealing process is terminated prematurely to ensure system safety. Specifically, when the return loss falls below a second preset value, the main controller generates an interrupt and uses the RF switch to switch the T-shaped matching circuit in the T-shaped matching circuit matrix to match the heat sealing head with varying capacitance. The second preset value is 9.5dB.

[0078] Example 2

[0079] The closed-loop control method of the medical heat sealer corresponding to the closed-loop control system of the medical heat sealer is described in detail in the system embodiment, and will not be repeated here. Figure 4 As shown, the following steps are included:

[0080] Clamp the pipe to turn on the power amplifier;

[0081] The main controller determines whether the received return loss is less than a first preset value. No-load or line damage can result in infinite impedance and total signal reflection. Pipeline damage and leakage can short-circuit the heat seal electrodes, causing total power reflection. To account for detection errors, the first preset value is set to 0.3dB in this embodiment.

[0082] If the return loss is less than the first preset value, it is determined that the line is damaged or unloaded, causing the heat sealing head electrodes to be short-circuited, and the heat sealing is stopped;

[0083] If the return loss is not less than the first preset value, continue heat sealing;

[0084] If the return loss is less than the second preset value, the main controller generates an interrupt and switches the impedance matching network through the radio frequency switch; in this embodiment, the second preset value is set to 9.5dB.

[0085] Determining again whether the return loss is less than a second preset value;

[0086] If the return loss is less than the second preset value, determining again whether the return loss is less than the first preset value;

[0087] If the return loss is less than the first preset value, it is determined that the pipeline is damaged and leaking, causing the heat sealing head electrodes to be short-circuited, and the heat sealing is stopped;

[0088] If the return loss is not less than the first preset value, the process jumps to the step of switching the impedance matching network through the RF switch if the return loss is less than the second preset value and continues to execute;

[0089] If the return loss is not less than the second preset value for a predetermined time, the heat sealing system is determined to be stable and the heat sealing is terminated. In this embodiment, the predetermined time is set to 300ms.

[0090] The impedance matching network is a T-shaped matching circuit matrix. The T-shaped matching circuit matrix is ​​obtained by the following steps:

[0091] According to the change of the distance between the upper and lower plates during the heat sealing process, the impedance of the heat sealing head at different distances was measured;

[0092] Obtaining the measured impedance of the heat sealing head at different distances between the plates of the heat sealing head;

[0093] A T-shaped matching circuit is added and parameters of the T-shaped matching circuit are adjusted on a Smith chart so that, at different distances between the plates of the heat sealing head, the impedance of the heat sealing head is within a preset range of a standard load, where the standard load is 50Ω. During the entire heat sealing process, the return loss is less than a second preset value at different distances between the plates of the heat sealing head, thereby obtaining a T-shaped matching circuit matrix.

[0094] Example 3

[0095] An electronic device 200, such as Figure 5 As shown, the method includes, but is not limited to, a memory 201 storing program code; a processor 202 connected to the memory, and when the program code is executed by the processor, a wrist fracture rehabilitation training motion recognition method is implemented. For a detailed description of the method, please refer to the corresponding description in the above method embodiment and will not be repeated here.

[0096] Example 4

[0097] A computer-readable storage medium such as Figure 6 As shown, program instructions are stored thereon, and when the program instructions are executed, a wrist fracture rehabilitation training action recognition method is implemented. For a detailed description of the method, reference can be made to the corresponding description in the above method embodiment, which will not be repeated here.

[0098] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0099] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0100] The above are merely examples of the present invention and are not intended to limit one or more embodiments of the present invention. For those skilled in the art, various modifications and variations of one or more embodiments of the present invention may be made. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present invention shall be included within the scope of the claims of one or more embodiments of the present invention.

Claims

1. A closed-loop control system for a medical heat sealer, characterized in that: It includes main controller, power amplifier, active crystal oscillator, dual directional coupler, impedance matching network, RF switch, attenuator and power meter; among them, The active crystal oscillator is connected to the power amplifier to generate a high-frequency signal; The high-frequency signal is coupled to a low-power radio frequency signal through the dual-directional coupler; The output port of the dual directional coupler outputs the main signal to the impedance matching network; The impedance matching network is used to match the impedance of the heat sealing head; The low-power radio frequency signal is attenuated by the attenuator; The power meter detects the attenuated signal to obtain forward power and reflected power, and feeds the forward power and reflected power back to the main controller; The main controller adjusts the power amplifier according to the forward power and the reflected power, calculates the return loss, and switches the impedance matching network through the radio frequency switch; The load change during the heat sealing process is the capacitance change caused by the decrease in the distance between the electrodes of the heat sealing head. The capacitance calculation formula of the heat sealing head is: ； in, is the dielectric constant, is the area facing the plates, is the electrostatic force constant, is the plate spacing; The impedance matching network uses series-parallel inductance to offset the impedance mismatch caused by the capacitance change of the heat sealing head; The impedance matching network is a series-parallel inductance network with m*n increasing in sequence. shaped matching circuit matrix; wherein m is the number of columns of the matching circuit matrix, and n is the number of rows of the matching circuit matrix; The calculation formula of the return loss is: ； in, is the input power, is the reflected power, is the return loss; When the return loss is less than a first preset value, it is determined that the line is damaged or unloaded, resulting in a short circuit of the heat sealing head electrodes, and heat sealing is stopped; When the return loss is less than a second preset value, the main controller generates an interrupt and switches the The matching circuit matrix A shape matching circuit is used to match the thermal seal head with changing capacitance.

2. A closed-loop control system for a medical heat sealer according to claim 1, characterized in that: It also includes a filter, and the high-frequency signal is filtered by the filter and then transmitted to the dual directional coupler.

3. A closed-loop control system for a medical heat sealer according to claim 1, characterized in that: The first preset value is 0.3dB.

4. A closed-loop control system for a medical heat sealer according to claim 1, characterized in that: The second preset value is 9.5dB.

5. A closed-loop control system for a medical heat sealer according to claim 1, characterized in that: described The shape matching circuit includes a capacitor, a first inductor, and a second inductor, one end of the first inductor is connected to the capacitor, the other end of the first inductor is connected to one end of the second inductor, and the other end of the second inductor is grounded.

6. A closed-loop control method for a medical heat sealer according to any one of claims 1 to 5, characterized in that: The following steps are involved: Determining whether the return loss is less than a first preset value; If the return loss is less than a first preset value, it is determined that the line is damaged or unloaded, resulting in a short circuit of the heat sealing head electrodes, and the heat sealing is stopped; If the return loss is not less than the first preset value, continue heat sealing; If the return loss is less than a second preset value, switching the impedance matching network through the radio frequency switch; Determining again whether the return loss is less than a second preset value; If the return loss is less than the second preset value, the process jumps to the step of switching the impedance matching network through the radio frequency switch and continues to execute if the return loss is less than the second preset value; If the return loss is not less than a second preset value for a predetermined period of time, it is determined that the heat sealing system is stable and the heat sealing is terminated; Before jumping to the step of switching the impedance matching network by the radio frequency switch if the return loss is less than the second preset value and continuing to execute, the following steps are also included: If the return loss is less than the second preset value, determining again whether the return loss is less than the first preset value; If the return loss is less than a first preset value, it is determined that the pipeline is damaged and leaking, causing the heat sealing head electrodes to be short-circuited, and the heat sealing is stopped; If the return loss is not less than the first preset value, the process jumps to the step of switching the impedance matching network through the radio frequency switch if the return loss is less than the second preset value and continues to execute; The impedance matching network is shaped matching circuit matrix, the The acquisition of the shaped matching circuit matrix includes the following steps: Obtaining the measured impedance of the heat sealing head at different distances between the plates of the heat sealing head; On the Smith chart The parameters of the shape matching circuit are adjusted so that the impedance of the heat sealing head is within the preset range of the standard load at different distances between the plates of the heat sealing head, and the return loss at different distances between the plates of the heat sealing head during the entire heat sealing process is greater than the second preset value, and the Shape matching circuit matrix.

7. An electronic device, characterized in that: include: a memory having program code stored therein; A processor is coupled to the memory and implements the method according to claim 6 when the program code is executed by the processor.

8. A computer-readable storage medium, characterized in that Program instructions are stored thereon, and when the program instructions are executed, the method according to claim 6 is implemented.

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