Artificial Nose and Its Control Method

Abstract

The present invention discloses an artificial nose, which includes a breathing pipeline. The breathing pipeline includes an inlet end and an outlet end. A gas passage is formed in the part of the breathing pipeline between the inlet end and the outlet end. The inlet end is connected with a humidifying device. It is characterized in that: the artificial nose further includes a heater capable of heating the gas in the breathing pipeline. A sensor capable of detecting the temperature and humidity of the gas is arranged at the outlet end of the breathing pipeline, so as to control the heater and the humidifying device according to the values collected by the sensor. A control method for the artificial nose as described above is also disclosed. Compared with the prior art, the advantages of the present invention are as follows: by arranging the humidifying device and the heater, the functions of automatically controlling the temperature and humidity of the inhaled gas can be realized, which helps the tracheotomy patients to maintain the airway for a long time.

Description

Technical Field

[0001] The present invention relates to medical devices, in particular to an artificial nose and a control method thereof. Background Art

[0002] Under normal circumstances, the respiratory tract of the human body warms and humidifies the air inhaled into the body, mainly relying on the evaporation of moisture from the nasal cavity, pharynx, trachea and bronchial mucosa to obtain warming and humidification. Clinically, for some critically ill patients, an artificial airway (artificial nose) needs to be established.

[0003] The so-called artificial airway refers to an effective connection established between the physiological airway and air or other gas sources to ensure airway patency. For patients who need to maintain the airway for a long time or cannot be intubated through the laryngeal trachea, tracheotomy is required to establish a definitive artificial airway. After the artificial airway is established, the inhaled gas must be warmed and humidified entirely by the trachea and the lower respiratory tract, increasing the loss of water and heat in the airway and easily causing complications such as atelectasis or pulmonary infection.

[0004] Currently, most domestic research focuses on artificial airway humidification techniques and the selection of humidifying fluids. For example, a reusable artificial nose disclosed in a Chinese patent with the application number 201920584454.6 includes a housing and a filter, a connector and a fixing rope inside the housing. The filter is made of a sponge, cotton fabric, activated carbon or a mixture that can filter or adsorb dust and keep moisture; another example is an artificial nose disclosed in a Chinese patent with the application number 201320599265.9, which includes a cover, a moisture-absorbing and breathable filter layer, an oxygen inhalation pipe and at least one humidifying pipe. The cover is filled with the filter layer, and the oxygen inhalation pipe and the humidifying pipe are installed on the cover, above the filter membrane, for dripping the humidifying fluid into the filter layer.

[0005] For inpatients, the temperature in the ward is mostly appropriate, so the requirement for warming is not as obvious as that for humidification. However, for patients who need home care or temporarily leave the hospital for activities, the warming and humidification of the gas are equally important, especially in cold winters, and this need is more urgent. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide an artificial nose that can provide appropriate gas warming and humidification in view of the deficiencies of the above-mentioned prior art.

[0007] The second technical problem to be solved by the present invention is to provide a control method for the above artificial nose.

[0008] The technical solution adopted by the present invention to solve the above first technical problem is as follows: An artificial nose includes a breathing pipeline, the breathing pipeline includes an inlet end and an outlet end, a part of the breathing pipeline between the inlet end and the outlet end forms a gas passage, and a humidifying device is connected to the inlet end. The artificial nose is characterized in that: the artificial nose further includes a heater capable of heating the gas in the breathing pipeline, and a sensor capable of detecting the temperature and humidity of the gas is arranged at the outlet end of the breathing pipeline, so that the heater and the humidifying device can be controlled according to the values collected by the sensor.

[0009] In order to meet both fast heating and energy saving, the heater is a carbon fiber heating wire and is wound around the outer periphery of the breathing pipeline.

[0010] Preferably, for facilitating the detection of the gas temperature and humidity, the sensor includes a temperature and humidity sensor for detecting the temperature and humidity of the gas.

[0011] Preferably, for facilitating humidification with less electric energy, the humidifying device is an ultrasonic atomizer, and the ultrasonic atomizer is connected to the inlet end of the breathing pipeline.

[0012] Further, the artificial nose further includes a liquid storage container for supplying liquid to the ultrasonic atomizer.

[0013] For facilitating the filtration of the inhaled air, an air filter is arranged at the inlet end of the breathing pipeline.

[0014] For facilitating energy conservation so as to automatically enter a low-power state when not in use, the sensor further includes a flow sensor for detecting the gas flow rate.

[0015] For facilitating the control of the entire working process of the artificial nose, the artificial nose further includes a controller, and the controller can receive the signals of the sensor, so as to control the humidifying device and the heater through a driving circuit.

[0016] The technical solution adopted by the present invention to solve the above second technical problem is as follows: A control method for an artificial nose as described above, characterized in that: it includes the following steps:

[0017] 1) Start. After power-on, the system is initialized;

[0018] 2) Read the preset upper and lower temperature limits and the preset upper and lower humidity limits;

[0019] 3) Read the current temperature T and humidity RH collected by the sensor;

[0020] 4) Compare the currently read temperature T with the preset lower temperature limit value, and compare the currently read humidity RH with the preset lower humidity limit value. Determine whether T or RH is lower than their respective preset lower limit values. If so, proceed to step 5); if not, return to step 3) or send the currently collected T and RH to the outside.

[0021] 5) If T is lower than the preset lower temperature limit value, control the heater to operate. If RH is lower than the preset lower humidity limit value, control the ultrasonic nebulizer 2 to operate, thereby adjusting the temperature and humidity of the gas in the breathing tube to within the preset range.

[0022] Preferably, in step 4), specifically, it includes the following steps:

[0023] 4.1) Set the temperature and humidity parameters in advance according to the requirements of PID control, and then initialize.

[0024] 4.2) Read the currently measured temperature T and humidity RH of the sensor, as well as the preset ranges of temperature and humidity respectively, and calculate the difference between T and the preset lower temperature limit value, and calculate the difference between RH and the preset lower humidity limit value.

[0025] 4.3) Obtain the output variable of PID control based on the difference, and control the ultrasonic nebulizer and heater to operate separately or simultaneously according to this output variable, so that the temperature and humidity of the gas at the outlet end are within their respective preset ranges; then proceed to step 5).

[0026] Compared with the prior art, the advantages of the present invention are as follows: By setting a humidifying device and a heater, the temperature and humidity of the inhaled gas can be automatically controlled, which helps tracheotomy patients maintain the airway for a long time; By setting an ultrasonic nebulizer and a liquid storage container, medical staff or patients can choose different humidifying liquids, not just water; When the patient needs to inhale atomized medicine for treatment, only need to replace the water in the liquid storage container with the required medicine, or directly replace it with a liquid storage container filled with medicine, then the artificial nose of the invention can serve as the function of a common ultrasonic nebulizer for the patient to take medicine, further expanding the scope of use of the device and realizing multiple functions with one machine. Description of the Drawings

[0027] Figure 1 It is the structural block diagram of the artificial nose according to the embodiment of the present invention;

[0028] Figure 2 It is the circuit schematic diagram of the artificial nose according to the embodiment of the present invention;

[0029] Figure 3 It is the main program flow chart of the artificial nose according to the embodiment of the present invention;

[0030] Figure 4 Flowchart of the subroutine of the artificial nose according to an embodiment of the present invention. Detailed implementation manners

[0031] The present invention will be further described in detail below in conjunction with the embodiments with reference to the drawings.

[0032] Refer to Figure 1 , an artificial nose, including a breathing pipeline 1, an ultrasonic nebulizer 2, a liquid storage container 3 and a controller 4.

[0033] Among them, the breathing pipeline 1 has an inlet end 11 and an outlet end 12. The part between the inlet end 11 and the outlet end 12 is a hollow pipeline to form a gas passage. A heater 7 is arranged at a position between the inlet end 11 and the outlet end 12 in the breathing pipeline 1. In this embodiment, preferably, the heater 7 is a carbon fiber heating wire wound around the outer periphery of the breathing pipeline 1. An air filter 5 is arranged at the inlet end 11, and a sensor 6 is arranged at the outlet end 12. The sensor 6 includes a temperature and humidity sensor and a flow sensor, and is used to detect the temperature and humidity of the gas flowing out of the breathing pipeline 1 and the gas flow rate. The outlet end 12 of the breathing pipeline 1 serves as a respiratory tract access site for connecting with the patient's respiratory tract.

[0034] The breathing pipeline 1 is the main path for the patient's gas to enter and exit, and is also an important place for heating and humidifying the inhaled gas. The breathing pipeline 1 is preferably made of a foaming material, having a good heat insulation effect, ensuring that the gas in the breathing pipeline 1 is not easily affected by the external environmental temperature.

[0035] The heater 7 (such as a carbon fiber heating wire) arranged on the outer periphery of the breathing pipeline 1. After the carbon fiber is electrified, it has a fast heating rate, high efficiency, but low cost, and the electrothermal conversion rate can reach more than 99.9%. It is the heating element of the mainstream electric heating clothing in the current market. Utilizing these advantages of the carbon fiber, it can be more energy-saving than using ordinary electric heating wires. A layer of insulating and heat-insulating protective film with a heat reflection effect is further wrapped outside the carbon fiber to minimize the heat loss as much as possible and also protect the carbon fiber.

[0036] When dry and low-temperature gas (air and water mist) flows in the breathing pipeline 1, the carbon fiber heating wire is electrified to continuously heat the low-temperature gas, so that the temperature of the gas in the breathing pipeline 1 rises; once the temperature in the breathing pipeline 1 reaches the expected value or is about to reach the expected value, the carbon fiber heating wire stops heating or intermittently heats at a certain time interval to prevent the gas from overheating and causing damage to the respiratory tract.

[0037] The outlet of the above ultrasonic nebulizer 2 is connected to the inlet end 11 of the breathing tube 1, and at the same time, the liquid storage container 3 provides water source for the ultrasonic nebulizer 2. The liquid storage container 3 is mainly used to store the water required by the ultrasonic nebulizer 2 and is internally provided with a cotton core with water absorption capacity. Under the action of the capillary principle, water is continuously delivered to the nebulizer through the cotton core and is further atomized by the ultrasonic wafer.

[0038] Ultrasonic atomization is to apply the amplified high-frequency oscillation signal to the ultrasonic piezoelectric wafer, and at room temperature, the molecular bonds between liquid water molecules can be broken to generate natural floating water mist. This is a pure physical change process, without heating or adding any chemical reagents, and has the characteristics of energy saving and safety. Compared with the heating atomization method, this method can save 90% of the energy.

[0039] The main means for the ultrasonic nebulizer 2 to increase humidity is to control the working time of the ultrasonic nebulizer 2 through the controller 4, so as to achieve the purpose of regulating humidity. Taking advantage of the advantages of ultrasonic atomization, it can achieve the purpose of humidification with less electric energy. This has significant significance for reducing the power consumption of the artificial nose and extending its service life. Of course, other humidifying devices can also be used, such as those mentioned in the background technology.

[0040] Preferably, the liquid storage container 3 can be a liquid storage bottle, the caliber of which is the same as that of the drinking water packaging bottles available in daily life (such as the specifications of about 550 ml or 350 ml), which can not only ensure its convenient connection with the ultrasonic nebulizer 2, but also ensure convenient water replenishment in case of emergency, such as purchasing bottled water nearby or replacing it with the spare bottled water. Alternatively, the liquid storage container 3 can also be designed as a soft package like an infusion bag, in a more wearable manner to improve the comfort of the patient wearing this device.

[0041] By setting the ultrasonic nebulizer 2 and the liquid storage container 3, medical staff or patients can choose different humidifying fluids, not just water; when the patient needs to inhale atomized medicine for treatment, only need to replace the water in the liquid storage container 3 with the required medicine, or directly replace it with a liquid storage container 3 filled with medicine, then the requirements of the patient for atomized inhalation of medicine can be met. At this time, the invented artificial nose acts as the function of an ordinary ultrasonic nebulizer for the patient to take medicine, further expanding the use range of this device and realizing multiple functions with one machine.

[0042] The artificial nose device of the present invention can be integrally designed inside a wearable vest or clothing. On the one hand, it can effectively disperse the weight of the device, increase the degree of fitting between the device and the patient, and further improve the comfort of the patient when wearing and using the device. On the other hand, since this device is used in winter with low temperature and low humidity, adding a "piece of clothing" embedded with this device will basically not affect the patient's life; it helps the patient to use it in a low-temperature environment, rather than being limited to a warm indoor environment, increasing the patient's range of activities and bringing convenience to the patient's life and work; moreover, relying on the patient's body temperature, it can better ensure that the temperature of the gas in the pipeline is maintained near the body temperature, thus greatly reducing the electrical energy consumed by heating and prolonging the working time of the artificial nose.

[0043] In addition, buttons can be set to operate the artificial nose, such as for data setting, initialization, etc.

[0044] See Figure 2 , which is the circuit schematic diagram of the artificial nose of the present invention. The above ultrasonic nebulizer 2, sensor 6 and heater 7 are all electrically connected to the controller 4 and controlled by the controller 4. Since the control circuits of the ultrasonic nebulizer 2 and the heater 7 are relatively similar, in order to simplify the circuit diagram, this part of the circuit is not shown in Figure 2 .

[0045] The sensor 6 includes a temperature and humidity sensor and a flow sensor. The collected temperature and humidity data and flow data are sent to the controller 4, from which it is judged whether heating or humidification is required. The temperature and humidity sensor is used to detect the temperature and humidity of the gas in the breathing pipeline 1. In this embodiment, the temperature and humidity sensor uses the SHT31 high-precision temperature and humidity sensor produced by Sensirion of Switzerland, with a maximum working range of -40 - 125°C, 0 - 100% RH (relative humidity), and an accuracy of ±0.3°C, ±2% RH. The sensor supports a wide voltage input of 2.4 - 5.5V, uses I2C bus communication, and has a communication speed of up to 1MHz. The flow sensor is used to detect the change in the gas flow in the breathing pipeline 1. When the pressure difference (breathing flow) is less than a certain value for a long time, it can be judged that the current system is not in the working state and set to the standby mode to reduce power consumption. In this embodiment, the flow sensor solution uses the SM5651-001-D differential pressure sensor. The front and back sides of this pressure chip sense different pressures through the pressure nozzles, thereby forming a pressure difference and generating a voltage signal proportional to the pressure difference value.

[0046] In this embodiment, the controller 4 uses STM32F103C8T6 produced by STMicroelectronics. This is a 32-bit microcontroller based on the ARM Cortex-M core STM32 series. The program memory capacity is 64 kB, the operating voltage is 2V - 3.6V, and the operating temperature is -40°C - 85°C. Its powerful computing ability and low power consumption are very suitable for this invention. The above temperature and humidity sensor and flow sensor are connected to the I / O ports of the controller 4. The controller 4 is connected to the heater 7 through a drive circuit. In this embodiment, the drive circuit is composed of transistors (T1, T2) and their peripheral circuits.

[0047] Since the artificial nose of this invention is designed to be wearable, compared with the existing artificial nose, it does not have a liquid crystal screen for the following two main reasons: First, considering the particularity of this device, if a liquid crystal screen is equipped, the patient needs to lower their head to read the data, which is very inconvenient; Second, this device is designed to be wearable. If a liquid crystal screen is added, the patient needs to be careful to prevent the liquid crystal screen from being impacted by external forces during use, which will also bring inconvenience and even danger.

[0048] Although the liquid crystal screen is cancelled, due to the popularity of smartphones or tablets, it can be connected to smart terminals such as mobile phones via Bluetooth to send out data and display it on the App of the smart terminal. In this embodiment, the artificial nose is also provided with a Bluetooth module 8. In this embodiment, it is an HC-06 Bluetooth module based on the CSR BC417 chip, configured in the master-slave mode, and the data interface is the serial port UART. The Bluetooth module 8 is mainly used to send data, so it can be connected to the controller 4 through the serial port.

[0049] To ensure the normal operation of the artificial nose, a power supply is also included. In this embodiment, preferably, the power supply is composed of 3 groups of 3 rechargeable 18650 lithium batteries connected in series and then in parallel, with a voltage of 12.6V. The charging management chip uses AX3703, with 12V input voltage regulation and constant voltage charging mode. The 3.3V operating voltage required by devices such as the controller 4, Bluetooth module 8, and temperature and humidity sensor is obtained by converting the 12V voltage through a power conversion chip.

[0050] During operation, the ultrasonic nebulizer 2 atomizes the water in the liquid storage container 3 and mixes it with the air filtered by the air filter 5, and then enters the breathing tube 1. Then, the mixed gas is heated by the heater 7 wound around the outer periphery of the breathing tube 1, and is made into hot and humid air that meets the predetermined requirements through program control. The sensors at the outlet end 12 monitor the temperature and humidity of the gas about to enter the respiratory tract and feedback to the controller 4. The controller 4 adjusts the control strategy in a timely manner according to the program algorithm - whether to continue heating or humidifying. The temperature and humidity after the above adjustment and control can be sent to the mobile phone via Bluetooth, and the temperature and humidity curve can be displayed in cooperation with the App for observation or review of the record.

[0051] In the breathing pipeline 1 of the artificial nose of the present invention, the temperature and humidity changes of the gas are non-linear. In order to overcome the time lag of the traditional control method, PID feedback control is adopted in the present invention.

[0052] See Figure 3 and Figure 4 , the control method of the artificial nose of the present invention includes the following steps:

[0053] 1) Start. After power-on, the system is initialized;

[0054] 2) Read the upper limit value and lower limit value of the preset temperature, and the upper limit value and lower limit value of the humidity respectively. The range between the upper limit value and lower limit value of the preset temperature is the preset temperature range, and the range between the upper limit value and lower limit value of the preset humidity is the preset humidity range; the above ranges include their respective upper limit values and lower limit values;

[0055] 3) Read the temperature T and humidity RH currently collected by the temperature and humidity sensor;

[0056] 4) Compare the currently read temperature T and humidity RH with the preset temperature and humidity ranges, and determine whether one of them is lower than the set lower limit value. If so, go to step 5); if not, go to step 6);

[0057] 5) The controller 4 starts the drive circuit. If T is lower than the preset temperature lower limit value, control the heater 7 to work. If RH is lower than the lower limit value of the preset humidity range, control the ultrasonic atomizer 2 to work, and adjust the temperature and humidity of the gas in the breathing pipeline 1 to the preset range;

[0058] 6) The controller 4 sends a signal to the Bluetooth module 8 through the serial port (UART port);

[0059] 7) Judge whether the sending is completed. If so, return to step 3). After one cycle, the controller 4 reads the temperature and humidity measured by the temperature and humidity sensor again; if not, repeat this step.

[0060] The above process runs repeatedly to form the main program loop. Alternatively, after step 5), the controller 4 can also directly read the temperature and humidity measured by the temperature and humidity sensor again without the data sending step.

[0061] See Figure 4 , the subroutine for the operation of the artificial nose of the present invention is the core of the entire control program, that is, step 4) in the above main program. Specifically, it includes the following steps:

[0062] 4.1) Set the temperature and humidity parameters in advance according to the requirements of PID control, and then initialize;

[0063] 4.2) Read the currently measured temperature T and humidity RH of the temperature and humidity sensor, as well as the preset ranges of temperature and humidity respectively, calculate the difference between T and the preset lower temperature limit value, and calculate the difference between RH and the preset lower humidity limit value; it is also possible to calculate the increments of the currently measured temperature and humidity relative to the data measured last time;

[0064] 4.3) Obtain the output variable of the PID control according to the differences. That is, this output variable needs to control the ultrasonic atomizer 2 and the heater 7 to work separately or simultaneously, so that the temperature and humidity of the gas at the outlet end 12 are within the ranges between their respective preset upper and lower limit values. The relationship between the output variable and the target value of the temperature or humidity change (the respective upper limit value or a certain value between the upper and lower limit values) can be obtained through experiments; update the obtained output variable of the PID control as the new control variable, and then enter step 5) of the main program to drive the corresponding actuator to respond. The actuator refers to the drive circuits of the ultrasonic atomizer 2 and the heater 7.

Claims

1. An artificial nose, comprising a breathing tube (1), the breathing tube (1) including an inlet end (11) and an outlet end (12), a portion of the breathing tube (1) located between the inlet end (11) and the outlet end (12) forming a gas passage, the inlet end (11) being connected to a humidifying device, characterized in that: The artificial nose further includes a heater (7) capable of heating the gas in the breathing tube (1). A sensor (6) capable of detecting the temperature and humidity of the gas is provided at the outlet end (12) of the breathing tube (1), so that the heater (7) and the humidifying device can be controlled according to the values collected by the sensor (6). The humidifying device is an ultrasonic nebulizer (2). The ultrasonic nebulizer (2) is connected to the inlet end (11) of the breathing tube (1). The artificial nose further includes a liquid storage container (3) for supplying water or liquid medicine to the ultrasonic nebulizer (2). The caliber of the liquid storage container (3) is the same as that of a drinking water packaging bottle.

2. The artificial nose according to claim 1, wherein: The heater (7) is a carbon fiber heating wire and is wound around the outer periphery of the breathing tube (1).

3. The artificial nose according to claim 1 or 2, characterized in that: The sensor (6) includes a temperature and humidity sensor for detecting the temperature and humidity of the gas.

4. The artificial nose according to claim 1 or 2, characterized in that: An air filter (5) is provided at the inlet end (11) of the breathing tube (1).

5. The artificial nose according to claim 1 or 2, characterized in that: The sensor (6) further includes a flow sensor for detecting the gas flow rate.

6. The artificial nose according to claim 1 or 2, characterized in that: The artificial nose further includes a controller (4). The controller (4) can receive the signal of the sensor (6), so as to control the humidifying device and the heater (7) through a driving circuit.

7. A control method for an artificial nose according to any one of claims 1 to 6, characterized in that: It includes the following steps: 1) At the beginning, after power-on, the system is initialized; 2) Read the preset upper and lower temperature values and the preset upper and lower humidity values; 3) Read the current temperature T and humidity RH collected by the sensor (6); 4) Compare the read current temperature T with the preset lower temperature value, and compare the read current humidity RH with the preset lower humidity value. Judge whether T or RH is lower than their respective preset lower limit values. If so, go to step 5); if not, return to step 3) or send the currently collected T and RH to the outside; 5) If T is lower than the preset lower temperature value, control the heater (7) to work. If RH is lower than the preset lower humidity value, control the ultrasonic nebulizer (2) to work, so as to adjust the temperature and humidity of the gas in the breathing tube (1) to the preset range.

8. The control method of the artificial nose according to claim 7, characterized in that: In step 4), specifically, it includes the following steps: 4.1) Set the temperature and humidity parameters in advance according to the requirements of PID control, and then initialize; 4.2) Read the current temperature T and humidity RH measured by the sensor (6), as well as the preset ranges of temperature and humidity respectively, and calculate the difference between T and the preset lower temperature value, and calculate the difference between RH and the preset lower humidity value; 4.3) Obtain the output variable of PID control according to the difference, and control the ultrasonic nebulizer (2) and the heater (7) to work alone or simultaneously according to the output variable, so that the temperature and humidity of the gas at the outlet end (12) are within their respective preset ranges; Then go to step 5).

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