Efficient hot air circulation drying system for medical disinfection equipment

Abstract

The invention belongs to the technical field of medical instrument control, and particularly relates to an efficient hot air circulation drying system for medical disinfection equipment. According to the system, two working modes of drying and self-cleaning are thoroughly isolated from a logic source through mutually exclusive bimodal state machines in a modal arbitration and instruction distribution module, the system can only run in a determined modal at any moment, and modal switching must be subjected to strict idle state verification and confirmation completion, so that the system is simple in structure, low in cost and high in reliability. Therefore, the risk of false triggering and function conflict caused by logic coupling is eliminated, and the independence and integrity of the execution process of each mode are ensured.

Description

Technical Field

[0001] This invention belongs to the field of medical device control technology, specifically a high-efficiency hot air circulation drying system for medical disinfection equipment. Background Technology

[0002] In the field of medical equipment hygiene and disinfection, ensuring the sterility of instrument and equipment surfaces is a core element in preventing hospital-acquired infections and ensuring patient safety. Rapid drying and high-temperature sterilization using hot air are widely used techniques, and their effectiveness directly affects the final cleanliness of medical procedures.

[0003] Among them, the medical hot air drying and self-cleaning system is the key equipment to achieve the above goals. Such systems are usually designed with two working modes: one is the conventional hot air drying mode, which aims to quickly remove moisture from the surface of the instrument; the other is the high temperature self-cleaning mode, which aims to sterilize the internal air ducts and key components of the equipment through continuous high temperature airflow to meet strict medical sterility standards.

[0004] In existing technologies, drying and self-cleaning functions are often integrated under the same set of hardware and control logic. This leads to significant functional conflicts and interlock failure risks between the two modes in actual operation. Specifically, due to the shared control parameters and actuators, the system may accidentally trigger the high-temperature self-cleaning program during the drying operation due to sensor misjudgment or logic error. This not only interrupts the normal drying process but may also damage items that are not heat-resistant. Conversely, when the self-cleaning program needs to be executed to reach the sterilization temperature, the system may be constrained by the temperature control limiting mechanism set to protect the drying function, and may not be able to continuously output a high temperature sufficient to achieve effective sterilization, thus leaving potential hygiene and safety hazards. This intermodal control logic coupling and lack of reliable interlocking mechanisms make it difficult for the equipment to guarantee both drying efficiency and safety, as well as self-cleaning effectiveness.

[0005] Therefore, a high-efficiency hot air circulation drying system for medical disinfection equipment is proposed to address the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a high-efficiency hot air circulation drying system for medical disinfection equipment, so as to solve the technical contradictions in the prior art caused by the shared control logic and actuator between the drying and self-cleaning working modes, such as functional conflicts, false triggering risks, and failure to meet sterilization temperature standards.

[0007] To address the above technical issues, the following technical solution is adopted: a dual-modal interlocking control system for medical hot air drying and self-cleaning, which includes a modal arbitration and command distribution module, an independent parameter configuration and execution module, a physical interlocking and status feedback module, and a safety monitoring and anomaly handling module.

[0008] The modal arbitration and command distribution module, as the central decision-making unit of the system, receives external operation commands from the user interface or preset timings, and obtains the current system status information uploaded by the physical interlock and status feedback module in real time. This module has a built-in dual-modal state machine, which defines the hot air drying mode and the high-temperature self-cleaning mode as two mutually exclusive states with clear transition conditions. When a command to start either mode is received, the state machine first checks whether the current system status reported by the physical interlock and status feedback module is in an idle and interlock-released preparatory state. If the check passes, the state machine switches from the idle state to the running state corresponding to the target mode, and issues a control command set strictly bound to that mode to the independent parameter configuration and execution module. This control command set not only includes the start command, but also forcibly specifies the range and source of all subsequent control parameters. During the operation of either mode, the state machine will refuse to receive and block any command request to start the other mode until the current mode has been fully executed according to its preset process, and the physical interlock and status feedback module confirms that the actuator has been reset to a safe position. Only then does the state machine switch back to the idle state.

[0009] The independent parameter configuration and execution module includes a parameter configuration submodule and an execution driver submodule. The parameter configuration submodule internally stores two completely independent parameter databases that cannot be cross-called, corresponding to the hot air drying mode and the high temperature self-cleaning mode, respectively. The hot air drying parameter database includes temperature setting range, wind speed level mapping relationship, drying time threshold, and temperature protection upper limit for different instrument materials; The high-temperature self-cleaning parameter database includes sterilization temperature setpoints, continuous operating time at that temperature, wind speed strategies for maintaining high temperatures in the duct, and cooling curves for the self-cleaning cycle. When an instruction is received from the modal arbitration and instruction distribution module, the parameter configuration submodule strictly retrieves the complete set of parameters from the corresponding parameter database according to the modal identifier specified in the instruction. The execution drive submodule includes a heater drive unit, a fan drive unit, and a damper execution unit. The execution drive submodule receives real-time parameters provided by the parameter configuration submodule and generates corresponding pulse width modulation signals or analog voltage signals to independently control the power output of the heater, the speed of the fan, and the opening and closing angle of the damper. In hot air drying mode, the execution drive submodule dynamically adjusts the hot air temperature and flow rate according to the drying parameters; in high temperature self-cleaning mode, the execution drive submodule locks the output to a high power and a specific airflow pattern that is sufficient to make the air duct reach and maintain the sterilization temperature.

[0010] The physical interlock and status feedback module is the core of achieving hardware-level security isolation. This module includes a set of interlocking relays and a high-precision status sensor network. The interlocking relays are connected in series in the main power supply circuit of the heater and the control circuit of the fan. Their on / off state is directly controlled by the interlocking signal issued by the modal arbitration and command distribution module. When the system enters the hot air drying mode, the interlock relay will close the corresponding contact combination according to the power requirements of the drying mode; when the system switches to the high temperature self-cleaning mode, the interlock relay will disconnect the original contacts and close a set of contact combinations designed for continuous high power operation, ensuring that the power paths of the two modes are completely separated from the physical circuit. The status sensor network includes multi-point thermocouple temperature sensors arranged at the air inlet, core heating zone, and air outlet of the air duct, Hall sensors for monitoring the position of the damper, and photoelectric encoders for detecting the fan speed. The real-time data collected by these sensors is encapsulated into system status data packets and uploaded to the modal arbitration and command distribution module and the safety monitoring and anomaly handling module at a fixed frequency.

[0011] The safety monitoring and anomaly handling module continuously monitors the output signals of the independent parameter configuration and execution module, as well as the sensor data from the physical interlock and status feedback module. This module has preset multiple levels of safety thresholds and logical judgment rules. The first level of monitoring targets temperature parameters. In the hot air drying mode, if the temperature sensor reading at any point exceeds the protection limit in the modal parameter database for more than 2 seconds, the module will immediately send an overheating interruption request to the modal arbitration and command distribution module and record the event log. In high-temperature self-cleaning mode, the module monitors whether the temperature of the core heating zone can reach 95% of the sterilization temperature setting within the preset 3-minute start-up time. If it fails to reach 95%, it is determined to be a heating abnormality and an alarm is triggered. The second level of monitoring focuses on state consistency. The module compares the apparent mode, interlock relay status feedback signals, and the actual operating status of the main actuators. For example, when the system state machine is in the high-temperature self-cleaning mode, but the damper position sensor indicates that the damper is in a large opening state, which does not match the small opening circulation air mode required for self-cleaning, the module will immediately determine that the state interlock has failed, force the system into a fault shutdown state, and cut off the power to all actuators.

[0012] Preferably, the sterilization temperature setting value in the high-temperature self-cleaning parameter database is a dynamic value with a base value of 132 degrees Celsius, and can be finely adjusted according to the temperature uniformity coefficient in the historical operating data uploaded by the physical interlock and status feedback module; The temperature uniformity coefficient is calculated by taking the standard deviation of the temperature at three key monitoring points within the duct during the previous self-cleaning cycle. If the standard deviation is below 2 degrees Celsius, the temperature distribution is considered uniform, and the baseline setting is maintained. If the standard deviation is between 2 and 5 degrees Celsius, the system automatically increases the sterilization temperature setting by 3 degrees Celsius to compensate for any possible low-temperature areas. If the standard deviation is above 5 degrees Celsius, the system does not adjust the temperature setting but instead generates a duct inspection and maintenance alarm, indicating possible airflow blockage or sensor malfunction.

[0013] Preferably, the interlock relay in the physical interlock and status feedback module is a dual-coil magnetic latching relay. This relay is characterized by requiring only a short pulse signal to change and maintain the contact state, without continuous energization. The modal arbitration and command distribution module drives the relay by sending a 24V DC pulse signal with a duration of 100 milliseconds to a specific coil. This design not only reduces system standby power consumption, but more importantly, even if the main control unit experiences an unexpected power failure, the relay's mechanical contacts will remain in the state before the power failure, preventing the system from entering an incorrect mode due to logic initialization errors after power-on. This provides a hardware interlock memory function in the power-off state.

[0014] Preferably, the safety monitoring and anomaly handling module further includes a time-series prediction-based pre-fault diagnosis unit. This unit continuously analyzes the changing trends of the fan drive current, heater resistance value, and critical node temperature. The unit uses a sliding time window algorithm with a window length of the most recent 50 operating cycles. For the fan drive current, the unit calculates its effective value and harmonic components within a complete cycle and compares them with the standard health spectrum model of the fan model. When the harmonic component increases by more than 30% of the baseline, the bearing wear risk is predicted. For the heater resistance, the unit monitors its resistance change rate between cold and hot states. If the change rate exceeds 5% of the rated value, heating wire aging is predicted. The pre-fault diagnosis unit outputs the prediction results to the user interface in the form of a warning level and marks it in the system log, but does not directly interrupt the operation of the current mode unless other immediate safety rules are triggered simultaneously.

[0015] Preferably, in the hot air drying mode, the system employs a phased variable parameter control strategy in the drive submodule. This strategy divides the drying process into a rapid heating stage, a constant temperature drying stage, and a slow cooling stage. In the rapid heating stage, the heater operates at 85% of its rated power, and the fan runs at its highest speed. The goal is to bring the outlet temperature to the set value within 2 minutes. After entering the constant temperature drying stage, the system switches to a proportional-integral-derivative control algorithm, using the outlet temperature as feedback to dynamically adjust the heating power, keeping the temperature fluctuation within ±3 degrees Celsius of the set value. The fan speed is automatically matched according to the preset equipment type. One minute before the drying timer ends, the system enters the slow cooling stage, where the heater power linearly drops to 0, and the fan continues to run to dissipate residual heat. The system determines the drying process is complete only when the outlet temperature is below 50 degrees Celsius, and sends a completion signal to the modal arbitration and command distribution module.

[0016] The beneficial effects of this invention are: 1. This invention completely isolates the drying and self-cleaning working modes from the logical source by using a mutually exclusive dual-modal state machine in the modal arbitration and instruction distribution module. The system can only operate in one specific mode at any time, and the mode switching must be subject to strict idle state verification and completion confirmation. This eliminates the risk of false triggering and functional conflict caused by logical coupling and ensures the independence and integrity of each mode execution process.

[0017] 2. This invention establishes completely independent hardware control parameters and driving strategies for the two modes through independent parameter configuration and execution modules. Combined with the physical interlock and hardware interlock relays in the status feedback module, it achieves complete isolation from software parameters to hardware circuits. The high-temperature self-cleaning mode is not restricted by the temperature control limit of the drying mode and can continuously output stable sterilization-grade high temperature. Meanwhile, the hot air drying mode can operate efficiently in a safe and dedicated parameter space, avoiding the risk of damage from abnormal high temperature, thus ensuring both the effectiveness of sterilization and the safety of the drying process.

[0018] 3. Through the safety monitoring and anomaly handling module, this invention not only responds quickly and interrupts immediate dangers such as overheating and inconsistent status, but also predicts the health status of key components through the pre-fault diagnosis unit, realizing a leap from fault handling to fault prevention. The magnetic latching design adopted by the physical interlocking relay provides hardware-level safety memory in the power-off state, which greatly improves the robustness and reliability of the entire system when facing complex working conditions and unexpected situations. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] In the attached diagram: Figure 1 This is a schematic diagram of the overall technical solution architecture of the dual-modal interlocking control system for medical hot air drying and self-cleaning proposed in this invention. Figure 2 This is a schematic diagram of the core principle framework of the modal arbitration and instruction distribution module in this invention; Figure 3 This is a logical flow diagram of the independent parameter configuration and execution module in this invention; Figure 4 This is a schematic diagram of the multi-level interaction relationship and data flow between the physical interlock and status feedback module and the safety monitoring and anomaly handling module in this invention. Detailed Implementation

[0021] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0022] Specific implementation examples are given below.

[0023] Example 1 This invention provides a dual-modal interlocking control system for medical hot air drying and self-cleaning, the overall architecture of which is as follows: Figure 1 As shown, the system consists of four core functional units: a modal arbitration and instruction distribution module, an independent parameter configuration and execution module, a physical interlock and status feedback module, and a security monitoring and anomaly handling module. The modules interact with each other via a high-speed internal bus and strictly follow the preset logical control timing and state transition rules to ensure that the system can maintain modal isolation, operational safety, and functional integrity under any operating conditions. The following will describe in detail the specific structure, working principle, data flow, and interaction mechanism of each module with reference to the attached diagram.

[0024] Please refer to the attached document. Figure 1The entire system uses the modal arbitration and instruction distribution module as the central decision-making hub. Its input end is connected to the user operation interface or external timing controller, and its output end forms a two-way communication link with the independent parameter configuration and execution module and the physical interlock and status feedback module, respectively. The safety monitoring and anomaly handling module is connected in parallel to all key execution units and sensor nodes, forming a second safety loop independent of the main control logic. This ensures that even if the main control logic malfunctions, the safety monitoring module can still independently trigger protection actions based on the original sensor data, thereby achieving hardware-level redundancy protection.

[0025] The core of the modal arbitration and instruction dispatch module is a bimodal finite state machine embedded in the microcontroller; The bimodal finite state machine defines three basic states: idle preparation state, hot air drying operation state, and high temperature self-cleaning operation state; Among them, the hot air drying operation mode and the high temperature self-cleaning operation mode are mutually exclusive. There is no direct jump path between the two and they must be transferred through the idle preparation mode. The initial state of the state machine is the idle standby state. At this time, the system has completed the power-on self-test, all actuators have been reset to the safe position, the physical interlock relays are in the open state, and there are no unfinished modal tasks pending.

[0026] When the user selects the (hot air drying) function through the operation interface and confirms the start, the operation instruction is encapsulated into a data packet containing the modal identifier (01) and sent to the modal arbitration and instruction distribution module; this module first sends a status query request to the physical interlock and status feedback module to obtain a confirmation signal as to whether the current system is in an idle standby state; If confirmation is received, the state machine switches from the idle standby state to the hot air drying operation state and generates a control instruction set containing fields such as modal identifier (01), start command, target temperature, and instrument type code, which is then sent to the independent parameter configuration and execution module via the internal bus. At the same time, the module sends an interlock relay drive pulse signal to the physical interlock and status feedback module, instructing it to close the power supply contact combination corresponding to the hot air drying mode.

[0027] Conversely, if the user selects the (high temperature self-cleaning) function, the system will also perform the above verification process. Once the verification is successful, the state machine switches to the high temperature self-cleaning operation state and issues a control instruction set with modal identifier (10); In this state, the modal arbitration and command distribution module will block all (hot air drying) start requests from the user interface until the current self-cleaning process is fully completed and a (actuator has been reset) confirmation signal is received from the physical interlock and status feedback module before the state machine is allowed to switch back to the idle standby state.

[0028] Please refer to the attached document. Figure 2 The modal arbitration and instruction distribution module also integrates a status log recorder and a timing counter. The status log recorder uses non-volatile memory to record the timestamp, trigger source, previous state, target state and final execution result of each modal switch for subsequent fault tracing and compliance auditing. The timing counter is used to monitor the expected execution time of each modality. If the actual running time exceeds 1.5 times the preset upper limit, it is determined to be a process lag and a timeout interruption request is actively sent to the security monitoring and exception handling module.

[0029] Independent parameter configuration and execution modules, such as Figure 3 As shown, it consists of two parts: a parameter configuration submodule and an execution driver submodule. The parameter configuration submodule is internally divided into two physically isolated non-volatile storage areas, named the hot air drying parameter database and the high-temperature self-cleaning parameter database, respectively. The data structure stored in the hot air drying parameter database includes: Temperature setting range (40 degrees Celsius to 85 degrees Celsius), fan speed setting map (5 levels, corresponding to fan speeds of 1200 rpm, 1800 rpm, 2400 rpm, 3000 rpm, and 3600 rpm), drying time threshold (adjustable from 1 minute to 30 minutes), and temperature protection upper limits for three common instrument materials: stainless steel, plastic, and silicone (85 degrees Celsius, 70 degrees Celsius, and 60 degrees Celsius, respectively). The high-temperature self-cleaning parameter database includes: sterilization temperature setpoint (base value is 132 degrees Celsius), continuous running time (10 minutes), air speed strategy for maintaining high temperature in the air duct (fan runs at a constant speed of 2400 rpm, and damper opening is maintained at 15% to form circulating airflow), and cooling curve parameters (cooling rate is controlled to not exceed 8 degrees Celsius per minute).

[0030] When the parameter configuration submodule receives the control instruction set issued by the modal arbitration and instruction distribution module, it first parses the modal identifiers in it; If it is (01), then read the complete set of parameters from the hot air drying parameter database; If it is (10), it is read from the high-temperature self-cleaning parameter database. The reading process uses atomic operations to ensure that it is not interrupted by other interrupts during parameter loading; Once loading is complete, the parameters are passed to the execution driver submodule.

[0031] The execution drive submodule contains three independent power output channels: heater drive unit, fan drive unit, and damper execution unit; The heater drive unit adopts a full-bridge inverter topology, receives the real-time power setpoint from the parameter configuration submodule, and generates a 20 kHz pulse width modulation signal to drive the insulated gate bipolar transistor array, thereby precisely controlling the average power output of the heating wire. The fan drive unit is a brushless DC motor controller. After receiving the target speed command, it adjusts the motor phase current through closed-loop feedback to achieve a steady-state control accuracy of less than ±2% of the speed error. The damper actuator consists of a stepper motor and a reduction gear set. It receives opening angle commands (0% to 100% corresponds to 0 degrees to 90 degrees) and performs closed-loop correction through a built-in position encoder to ensure that the damper positioning error does not exceed ±1 degree.

[0032] In the hot air drying mode, the execution drive submodule adopts a staged variable parameter control strategy. This strategy divides the entire drying process into three consecutive stages: The process consists of a rapid heating phase, a constant temperature drying phase, and a slow cooling phase. During the rapid heating phase (lasting for 2 minutes), the heater operates at 85% of its rated power, and the fan operates at its maximum speed of 3600 rpm. The goal is to make the outlet temperature quickly approach the set value within a specified time. Once the constant-temperature drying stage begins, the system switches to a proportional-integral-derivative (PID) control algorithm, using the real-time reading from the outlet temperature sensor as feedback to dynamically adjust the heating power, ensuring that temperature fluctuations are strictly controlled within ±3 degrees Celsius of the set value. The fan speed is automatically matched according to the type of equipment: 3000 rpm for stainless steel equipment, 2400 rpm for plastic equipment, and 1800 rpm for silicone equipment. One minute before the drying timer ends, the system automatically enters the slow cooling phase. The heater power drops from the current value to 0 at a linear slope, and the fan continues to run until the outlet temperature is below 50 degrees Celsius. Only then does the execution drive submodule send a (drying complete) signal to the modal arbitration and command distribution module.

[0033] In high-temperature self-cleaning mode, the drive submodule locks the output to high power. The heater operates continuously at 100% rated power, the fan maintains a constant speed of 2400 rpm, and the damper opening is fixed at 15% to create a stable high-temperature circulating airflow within the duct. The system requires that the core heating zone temperature reach 95% of the sterilization temperature setpoint (i.e., 125.4 degrees Celsius) within 3 minutes of startup. If this requirement is not met, the safety monitoring and anomaly handling module will determine it as a heating anomaly.

[0034] Physical interlocking and status feedback modules, such as Figure 4 As shown, this is key to achieving hardware-level security isolation. The module consists of a set of dual-coil magnetic latching relays and a high-precision status sensor network. The interlocking relays have two sets of normally open contacts: The first group is used for the heater main circuit in the hot air drying mode, with a rated current of 16 amps; The second group is used for high-power heating circuits in high-temperature self-cleaning mode, with a rated current of 25 amps. The two sets of contacts are physically isolated and controlled by different coils. The modal arbitration and command distribution module drives the relay to operate by applying a DC pulse signal with a duration of 100 milliseconds and an amplitude of 24 volts to the corresponding coil; Because of the magnetic latching structure, the relay can maintain the contact state without continuous power supply after the pulse ends. This not only reduces the system's standby power consumption, but more importantly, the relay can still maintain the contact state before the power failure after the main control unit loses power unexpectedly. This prevents the system from accidentally entering high-power mode due to logic initialization errors when it is powered on again, thus providing a hardware interlock memory function in the power failure state.

[0035] The status sensor network includes three K-type thermocouple temperature sensors arranged at the air inlet, core heating zone and air outlet of the air duct, a Hall effect angle sensor for monitoring the position of the damper, and an incremental photoelectric encoder installed at the end of the fan shaft. All sensor data were acquired at a sampling frequency of 100 Hz and converted into 16-bit digital signals via an analog-to-digital converter. These data are encapsulated into system status data packets, including fields such as timestamps, sensor readings, and interlock relay status feedback (obtained through auxiliary contacts), and uploaded to the modal arbitration and command distribution module and the security monitoring and anomaly handling module at a frequency of 10 frames per second.

[0036] The safety monitoring and anomaly handling module constructs a multi-layered proactive safety protection system. The first level is temperature safety monitoring; In the hot air drying mode, the module compares the readings of the three temperature sensors with the temperature protection limit corresponding to the current instrument type in real time; If any sensor reading exceeds the upper limit and continues for more than 2 seconds, the module immediately sends an overheat interruption request to the modal arbitration and command distribution module, and at the same time cuts off the enable signal of the heater drive unit. Under high-temperature self-cleaning mode, the module monitors whether the temperature of the core heating zone reaches 125.4 degrees Celsius within 3 minutes; If the standard is not met, an alarm (heating abnormality) will be triggered and the event log will be recorded.

[0037] The second level is state consistency monitoring, in which the module continuously compares three key state variables: apparent mode (broadcast by the mode arbitration module), actual state of the interlocking relay (feedback from the auxiliary contacts), and actual operating state of the actuator (provided by the sensor network). For example, when the apparent mode is high-temperature self-cleaning, but the damper position sensor reports an opening greater than 30%, while the mode requires an opening of 15%, the module determines that the state interlock has failed, immediately forces the system into a fault shutdown state, and cuts off the power to all actuators through the hardware watchdog circuit.

[0038] The third level is the pre-fault diagnosis function. This function is implemented by a pre-fault diagnosis unit based on time series prediction. This unit uses a sliding time window algorithm with a window length of the most recent 50 operating cycles. For the wind turbine drive current, the unit calculates its effective value and harmonic components within a complete cycle and compares them with the standard health spectrum model of the wind turbine model. The standard health spectrum model is stored in non-volatile memory and includes the amplitude thresholds of the fundamental, third, and fifth harmonics. When the measured 5th harmonic component increases by more than 30% above the baseline, the unit predicts an early wear risk in the bearing and outputs a level one warning. For the heater resistance, the unit measures its cold resistance during each cold start and its hot resistance after thermal stabilization, calculating the rate of resistance change. If the rate of change exceeds 5% of the rated value, heating wire aging is predicted, and a level two warning is issued. All warning information is output to the user interface in the form of a level and marked in the system log, but does not interrupt the current modal operation unless the first level or second level security rule is triggered at the same time.

[0039] Furthermore, the sterilization temperature setpoint in the high-temperature self-cleaning parameter database is not fixed but dynamically adjusted based on historical operating data. After each self-cleaning cycle, the system calculates the standard deviation of the temperature at three key monitoring points within the duct, which serves as the temperature uniformity coefficient. If the standard deviation is below 2 degrees Celsius, it indicates that the temperature distribution is uniform, and the basic setting value of 132 degrees Celsius is maintained. If the standard deviation is between 2 and 5 degrees Celsius, the system will automatically increase the sterilization temperature setting value by 3 degrees Celsius, i.e., 135 degrees Celsius, to compensate for any possible low temperature areas. If the standard deviation is higher than 5 degrees Celsius, the system will not adjust the temperature, but will generate an alarm (duct inspection and maintenance) indicating that there may be airflow blockage or sensor drift failure.

[0040] In summary, this embodiment achieves comprehensive decoupling and interlocking of the two modes of medical hot air drying and high-temperature self-cleaning in terms of control logic, execution parameters, power supply circuits, and safety strategies through a logically mutually exclusive state machine, a physically isolated parameter library, hardware-level interlocking relays, and a multi-level safety monitoring system. This solves the functional conflicts and safety risks existing in the prior art and ensures the stable operation of medical equipment under high frequency and high reliability requirements.

[0041] Example 2 Based on the aforementioned Embodiment 1, this embodiment optimizes the interlock relay driving mechanism in the physical interlock and status feedback module to further improve the system's anti-interference capability and long-term operational reliability. Specifically, when generating interlock relay drive pulse signals, the modal arbitration and command distribution module no longer uses a single 100-millisecond fixed-width pulse, but introduces a pulse width modulation and readback verification mechanism.

[0042] When the system needs to switch from idle state to hot air drying mode, the mode arbitration and command distribution module first sends a drive pulse with an initial width of 80 milliseconds to the hot air drying dedicated coil; After the pulse is sent, the module immediately reads its actual status through the auxiliary contacts of the interlocking relay; If the contact is detected to be correctly closed within 10 milliseconds, the drive is considered successful; if no state change is detected, the module sends a compensation pulse of 120 milliseconds again after 50 milliseconds. If both attempts fail, the system determines that there is a relay fault, enters a safe shutdown state, and illuminates the (hardware interlock fault) indicator light.

[0043] Similarly, when switching to the high-temperature self-cleaning mode, the driving logic is the same, but the target is a high-power dedicated coil. This mechanism effectively addresses the problem of single-drive failure caused by relay contact oxidation, mechanical jamming, or driving voltage fluctuations, and significantly improves the success rate of hardware interlocking actions.

[0044] In addition, this embodiment enhances the algorithm of the pre-fault diagnosis unit in the safety monitoring and anomaly handling module. The original sliding time window algorithm only considers the data of the most recent 50 cycles, but may lead to insufficient data samples in long-term low-frequency use scenarios of equipment. To this end, this embodiment introduces a weighted historical data fusion strategy. When calculating the trend of wind turbine harmonic components, the unit not only uses the measured data of the most recent 50 cycles, but also introduces an exponential weighted average model with an attenuation factor of 0.95 to incorporate earlier historical health data into the calculation according to weight. Specifically, the weighted harmonic amplitude H_w(n) of the nth period is determined by the following formula: ; in, This is the measured amplitude of the 5th harmonic in the current cycle. This is the weighted value from the previous period. This formula ensures that the diagnostic model maintains sufficient stability and sensitivity even in the case of sparse data, avoiding false alarms caused by short-term data fluctuations.

[0045] Meanwhile, this embodiment adds an ambient temperature compensation mechanism for predicting heater resistance aging. Since the resistivity of a metal changes with ambient temperature, simply comparing the rate of change of resistance between hot and cold states may introduce errors. Therefore, the system simultaneously records the ambient temperature sensor reading each time it measures the cold resistance, corrects the reference resistance value based on the temperature coefficient of copper conductor (0.00393 degrees Celsius), and then calculates the rate of change. An aging warning is only triggered when the corrected rate of change exceeds 5%.

[0046] The above improvements significantly enhance the robustness of hardware drivers and the accuracy of fault diagnosis without altering the basic system architecture, making them particularly suitable for devices deployed long-term in medical environments with drastic temperature and humidity changes or uneven usage frequencies.

[0047] In the description of this invention, it should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions provided in this disclosure can be achieved, and no limitation is imposed herein.

[0048] The above description is merely a preferred embodiment of the present invention and does not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A dual-modal interlocking control system for medical hot air drying and self-cleaning, characterized in that, include: The modal arbitration and command distribution module is used to receive external operation commands and obtain the current status information of the system in real time. The modal arbitration and command distribution module is equipped with a dual-modal state machine, which defines the hot air drying mode and the high temperature self-cleaning mode as two mutually exclusive states. An independent parameter configuration and execution module is used to execute mode-bound control operations in response to the control instruction set. The independent parameter configuration and execution module includes a parameter configuration submodule and an execution drive submodule. The parameter configuration submodule internally stores two completely independent and non-interleaved parameter databases, corresponding to the hot air drying mode and the high-temperature self-cleaning mode, respectively. The parameter configuration submodule retrieves the complete set of parameters from the corresponding parameter database based on the mode identifier specified in the control instruction set. The execution drive submodule includes a heater drive unit, a fan drive unit, and a damper execution unit. The execution drive submodule receives real-time parameters provided by the parameter configuration submodule and generates corresponding control signals to independently control the heater's power output, the fan's speed, and the damper's opening and closing angle. The physical interlock and status feedback module is used to achieve hardware-level security isolation and provide system status feedback; the physical interlock and status feedback module includes a set of interlock relays and a status sensor network; the interlock relays are connected in series in the main power supply circuit of the heater and the control circuit of the fan, and their on / off state is controlled by the interlock signal issued by the modal arbitration and command distribution module; The safety monitoring and anomaly handling module is used to continuously monitor the output signals of the independent parameter configuration and execution module and the sensor data of the physical interlock and status feedback module, and to perform multi-level safety monitoring and anomaly handling.

2. The medical hot air drying and self-cleaning dual-mode interlocking control system according to claim 1, characterized in that, The mutual exclusion states include: When a command to start any mode is received, the dual-modal state machine first checks whether the current system state is in an idle and interlocked ready state. If the check passes, the dual-modal state machine switches from the idle state to the running state corresponding to the target mode and issues a set of control commands strictly bound to that mode to the independent parameter configuration and execution module. During the operation of any mode, the dual-modal state machine will refuse to receive and block any command request to start another mode until the current mode has been fully executed according to its preset process and the actuator has been confirmed to have been reset to a safe position. Only then will the dual-modal state machine switch back to the idle state.

3. The medical hot air drying and self-cleaning dual-modal interlocking control system according to claim 1, characterized in that, The security monitoring and anomaly handling module has preset multi-level security thresholds and logical judgment rules, which include: The first level of monitoring targets temperature parameters. In the hot air drying mode, if the temperature sensor reading at any point exceeds the protection limit in the mode parameter database, the safety monitoring and anomaly handling module will immediately send an overheating interruption request to the mode arbitration and command distribution module. In the high-temperature self-cleaning mode, the module monitors whether the temperature of the core heating zone can reach the set sterilization temperature within a preset time. If it fails to reach the set temperature, it is determined to be a heating anomaly and an alarm is triggered. The second level of monitoring targets state consistency. The module compares the apparent mode, interlock relay status feedback signals, and the actual operating status of the main actuators. When a state inconsistency is detected, the system is forced into a fault shutdown state.

4. The medical hot air drying and self-cleaning dual-mode interlocking control system according to claim 1, characterized in that, The interlocking relay in the physical interlocking and status feedback module is a dual-coil magnetic latching relay; the modal arbitration and command distribution module drives the interlocking relay to operate by sending DC pulse signals to the coil.

5. The medical hot air drying and self-cleaning dual-modal interlocking control system according to claim 1, characterized in that, The security monitoring and anomaly handling module also includes a pre-fault diagnosis unit based on time series prediction. The pre-fault diagnosis unit continuously analyzes the changing trends of fan drive current, heater resistance value, and critical node temperature. The pre-fault diagnosis unit employs a sliding time window algorithm; For the wind turbine drive current, the unit calculates its effective value and harmonic components over a complete cycle and compares them with the standard health spectrum model of the wind turbine model. When the harmonic components increase by more than 30% of the baseline, the risk of bearing wear is predicted. For the heater resistor, the pre-fault diagnosis unit monitors its resistance change rate between cold and hot states. If the change rate exceeds 5% of the rated value, it predicts that the heating wire is aging. The pre-fault diagnosis unit outputs the prediction results in the form of a warning level.

6. The medical hot air drying and self-cleaning dual-mode interlocking control system according to claim 1, characterized in that, In the hot air drying mode, the execution drive submodule adopts a staged variable parameter control strategy; The phased variable parameter control strategy divides the drying process into a rapid heating stage, a constant temperature drying stage, and a slow cooling stage.

7. The medical hot air drying and self-cleaning dual-mode interlocking control system according to claim 1, characterized in that, The modal arbitration and instruction distribution module also integrates a status log recorder and a timing counter. The status log recorder records the timestamp, trigger source, preceding state, target state, and final execution result of each modal switch. The timing counter is used to monitor the expected execution time of each modality. If the actual running time exceeds 1.5 times the preset upper limit, it is determined to be a process stagnation, and a timeout interruption request is actively sent to the security monitoring and exception handling module.

8. The medical hot air drying and self-cleaning dual-mode interlocking control system according to claim 4, characterized in that, The modal arbitration and command distribution module introduces a pulse width modulation and readback verification mechanism when generating the interlock relay drive pulse signal; When it is necessary to switch modes, the module first sends an initial drive pulse to the target coil. After the pulse is sent, it immediately reads the actual state through the auxiliary contact of the interlock relay. If the correct state change is not detected within 10 milliseconds, the module will send a compensation pulse again after 50 milliseconds. If both attempts fail, the system determines that the relay is faulty and enters a safe shutdown state.

9. The medical hot air drying and self-cleaning dual-mode interlocking control system according to claim 1, characterized in that, The state sensor network includes multi-point thermocouple temperature sensors arranged at the air inlet of the air duct, the core heating zone, and the air outlet, a Hall sensor for monitoring the position of the damper, and a photoelectric encoder for detecting the fan speed. The real-time data collected by the state sensor network is encapsulated into system state data packets and uploaded at a fixed frequency.

10. A dual-modal interlocking control system for medical hot air drying and self-cleaning according to claim 5, characterized in that, For heater resistance aging prediction, the pre-fault diagnosis unit adds an ambient temperature compensation mechanism; the system records the ambient temperature sensor readings simultaneously each time the cold resistance is measured, corrects the reference resistance value according to the temperature coefficient of the conductor, and then calculates the rate of change.

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