The title of the invention

Smart mask with automatic adaptability to face shape

Technical field of the invention

This invention falls under the technical field of protective face masks for use in polluted environments. (A41 D 13/11 , A61 M 16/06), but with the addition of a method for automatically detecting and fixing all types of leaks that develop between the mask sealing and the facial skin, with the goal of producing a flawless seal at the mask's edge. (A41 D 13/1176)

Invention background

Related documents found:

CN11 1184286A

US1 1202476B2

WO2014199378A1

GB2414188A

CN11 1184286A: This invention relates to a patch type seal mask that seals around the edge using a particular adhesive. When this mask is worn, the adhesive on its edge is placed on the person's face, completely sealing the edge of the mask. Additionally, the adhesives placed on the edge of the mask separate from the mask and stay on the person's face when the mask is removed from the face due to a protective layer in the lower part of the adhesive layers. In the present invention, an air cushion is used to create a seal on the edge of the mask instead of adhesion. As the internal air pressure of the cushion changes automatically, so does the seal's condition, and several sensors are positioned on the cushion's surface to enable this. The mask created by the current invention has the ability to be continuously reused, and only the filters of the mask need to be replaced at predetermined intervals that vary depending on the amount of use. In contrast to the mask created by the prior invention, which is disposable and thrown away after use.

US1 1202476B2: This invention discloses a continuous elongated ring, or CER for short, that can hold a breathing mask and is made of polymer materials. When non-woven masks are worn on the person's face with these rings, a complete seal is formed around the ring, preventing the entry of polluted air into the inner environment of the mask. These rings are long, continuous, and flexible and can fit the user's nose and mouth. This document also states that a spongy material is placed on the back of the ring to improve the sealing condition, make the user more comfortable, and keep the ring from slipping off the person's face. The operation of identifying and fixing the leakage between the face and the mask is carried out automatically by various sensors in the current invention, which is very different from this document. The current invention also includes the capability to show the location of the leak on a smart watch or mobile device. WO2014199378A1 : In this invention, a seal is created using one or more compressible cushions in the area of the mask body that covers the user's mouth and a portion of their nose. When the mask is put on a person's face, these cushions, which are filled with a liquid or gas, condense to create an exact seal around the mask. A similar method has been used in the present invention to create a seal between the mask and the person's face, with the exception that sensors placed on the surface of the air cushion allow for fully automatic leak detection and the ability to detect air leakage in various areas of the mask seal.

GB2414188A: In this invention, the inner edge of the mask has an air bag attached to it that is inflated three times to form a seal with the person's face. In the first method, the air is blown into the bag through a tube that is inserted inside the mask by the person using it. In the second method, the air bag is inflated using a manual air pump so that the user must manually inflate the seal portion after wearing the mask. The third method, however, substitutes an electric pump for the manual air pump, which uses a signal from a pressure sensor to inflate the air bag at the appropriate moment. The key feature of this invention, however, is an embedded pressure sensor that measures the air pressure inside the bag. If the pressure between the person's face and the pillow decreases, the air pressure inside the pillow does as well. The system detects this and turns on the air pump to tighten the mask's seal. In such systems, a predetermined threshold limit for air pressure is established, and if the pressure drops below that level, the air pump is activated. The main problem here is that the air pressure inside the bag may not change much and continue to fall within the acceptable range if there are small holes between the mask and the person's face. As a result, this invention lacks the capability of detecting tiny seams that result in air leakage in the sealing part of the mask. Even the smallest holes are found and automatically fixed in the current invention using a number of sensors positioned on the surface of the mask seal. In the current invention, it is also possible to show the precise location of the leak.

Summary

Depending on the face shapes of different people, different types of filtering masks may be worn on the face, but this may result in seams and holes that allow unfiltered, polluted air to enter the inner space of the mask, increasing the risk of coming into contact with contaminated environments. This invention describes a type of smart mask that uses sensors embedded in the seal portion to detect and seal up any seams and pores that develop between the mask seal and the person's face and lead to leaks. An empty bag that is filled with air makes up a portion of the sealing cushion that this invention has created. When the system detects a leak or the possibility of one, an electric air pump is triggered. By inflating the sealing cushion, this increases the pressure between the person's face and the mask, making it more comfortable. Other side functions of this mask include measuring the saturation percentage of blood gases, heart rate, and body temperature besides the main function of this mask that is to detect and automatically fix leaks in the sealing part. Additionally, this invention has the ability to display the precise location of a leak in the seal portion as well as a person's vital signs on a variety of smart devices, such as smart watches, in addition to the previously mentioned capabilities.

Brief Description of the Drawings [Fig.1 ] The interior of the mask with resistive touch-sensitive sensors positioned on the sealing cushion surface.

[Fig.2] The circuit for two follower emitters, which are used as transducers for resistive touch- sensitive sensors, is shown in this figure.

[Fig.3] The capacitive pressure sensor's structure and placement on the sealing cushion's surface.

[Fig .4] Exploded view of capacitive pressure sensor and its components.

[Fig.5] schematic depiction the capacitive proximity sensor's structure as well as the key design and operational parameters.

[Fig.6a] the pulse oximeter and optical touch detection sensor structure.

[Fig.6b] the change of different IR and R values of depending on the change of position of the finger in front of the sensor.

[Fig.7] The diagram of the absorption of light in various wavelengths and spectra by hemoglobin.

[Fig.8] The schematic depiction of the absorption spectrum of the pulse oximeter.

[Fig.9] After recording the wavelengths, a pulse oximeter outputs the final number in the form of a saturation percentage.

[Fig.10a] A visualization of how to show the user in the smart watch the location of the leak and any warnings.

[Fig.10b] A visualization of how to show the user the location of the leak and any warnings using a series of colors with various contrasts.

[Fig.10c] how to display various parameters and the option to choose the display type from a menu.

[Fig.1 1] a view of the sealing cushion's cross section as well as its and details.

[Fig.1 1 a] The components and parts of the air cushion system, which are broken down into three distinct parts, are depicted in this visualization as a block diagram.

[Fig.1 1 b] The components and parts of the air cushion system, which are split into two distinct parts, are depicted in this visualization as a block diagram.

[Fig.1 1c] The integrated air cushion system's parts and components are depicted in this visualization as a block diagram. [Fig.12] The protective frame has been removed from the mask, revealing the mask's exterior along with its filters and air transfer tubes.

[Fig.13] The neck case that contains the electronic circuits, air pumps, electric valves, and signal and air interfaces.

[Fig.14] The signal and air connectors in more detail.

[Fig .15] The general placement of the mask on the face as well as the placement of the case containing the electronic circuits on the person's neck.

Detailed description of the invention

In this invention, an air cushion is placed on the edge of the mask to create a seal that is suitable between the mask and the face. Several touch or pressure-sensitive sensors are placed on the surface of the air cushion, and when a hole or leak is detected in the seal of the mask, the air cushion will automatically inflate and the holes will be filled by expanding the cushion. The final sample may include one of the various methods disclosed in this document for identifying and fixing mask seal leakage, or it may combine two or more of these methods. As shown in Fig. 1. You can see that various electrodes (1 1 ) and sensors (10) have been positioned throughout the air cushion (1 12) in various locations. The electrode (11 ) near the bridge of the nose is wired to a 5-volt power supply, and the other members are sensors that pick up the electric current that travels through the body of the user. However, the high electrical impedance of the human body results in a weak electrical signal that must be amplified before it can be read by the sensors (10). The signal from the sensors is amplified and detected by a circuit made up of two follower emitters, also known as a Darlington pair, to address this problem. (Fig. 2)

The emitter of the first transistor (T1 ) is connected to the base of the second transistor (T2), the emitter of the second transistor (T2) is connected to ground, and the base of the first transistor (T1 ) is also considered as the sensor signal input. The transistors used are of the BJT and NPN types. The collector of both transistors in this set, which is used as a touch- sensitive sensor transducer, is connected to the supply voltage in order to set it up.

The transducer is essentially an open circuit when all of the sensors' connections to the skin of the face are severed, and the circuit current is zero. The signal output port is where the electric current enters the processor in this case. The system will then determine that the mask is unlikely to be on the person's face and stop inflating the sealing cushion.

However, an electric current enters the base of the first transistor when the mask is worn and the sensors are affixed to the user's face. The signal transmission from the transducer's output port is halted as a result of the transistors turning on and the circuit becoming charged electrically.

The signal transmission from the transducer is interrupted while the mask is worn and the sensors are in contact with the facial skin. If any of the sensors come into contact with the skin again, the signal will be sent once more and the system will detect the leak where the sensor's connection to the skin was broken. As previously mentioned, the body receives voltage from electrode 11 , which is situated near the bridge of the nose. The place of this organ was chosen because it typically has a good seal with the face and is connected to the bridge of the person's nose. The connection between this member (1 1 ) and the skin of the face may be broken, and there may be a leak or hole in this area, if the mask is on the face and the signal from all sensors is interrupted.

Fig 3 and 4: The use of a capacitive pressure sensor, which is very small and is attached to the outside of the sealing cushion (1 12), is the second method that may be successful in identifying seal leakage.

Several horizontal (42) and vertical (41 ) electrodes make up this sensor, which can be printed on any surface using printing technology. These electrodes are placed on top of one another, along with the dielectric (43), to form a group of pixels (32). Each of these pixels (32) functions as a pressure sensor and has a structure resembling a capacitor.

Leakage or the possibility of its existence is detected in this system by analyzing the amount of pressure between the person's face and the mask. The pressure between the mask and the person's face compresses each sensor pixel and shortens the distance between its plates. The capacitance is inversely correlated with the distance between the sensor plates, meaning that as the plates get closer to one another and that distance decreases, the capacitance increases.

A

C E _r EQ — a

In the formula above; C is the capacity of the capacitor, E _r is the dielectric coefficient, E ₀ is the electrical permeability constant of the vacuum, A is the area of the capacitor plates and d is the distance between the plates.

Fig. 5: Placing several capacitive proximity sensors on the surface of the sealing cushion is another way to find a leak in the mask seal.

A uniform electrostatic field is created between the two electrodes when the supply voltage is applied to them in this method, which uses two conductive electrodes placed next to one another at a distance of S, one of which serves as the transmitter and the other as the receiver. When the human body is viewed as a body with inherent capacitive behavior, it acts as a capacitor plate and creates a capacitive effect between the person's body and the sensor's transmitter plate. This results in the formation of capacitance between the two sensor electrodes. The capacitive capacity of the sensor changes as a result of the appearance of the capacitive effect between the person's body and the sensor plate, and the total capacitive capacity of the sensor is equal to:

^sensor ~ p T C b

The distance between the body surface and the sensor (d) determines how much of a change there is.

Fig. 6a: In the following method, a special optical sensor that bases its operation on how the human body reacts to light is used to detect the presence of touch between the skin of the face and the mask.

In this method, an optical sensor (66), which could be a photodiode or phototransistor, is positioned next to a light emitting diode assembly (65). When the mask is worn on the face, the sensor (69) completely adheres to the skin because the surface on which these two components are placed (67) is flexible and at the same level as the surface of the air cushion. The optical sensor (66) picks up the light that the LEDs (68), which may or may not be visible, emit into the facial tissue. The amount of light the optical sensor receives changes when the mask is moved away from the face, alerting the person to the presence of leaks or the potential for them. This method also allows for measuring the separation between the face and the mask seal.

Fig. 6b: The MAX30102 sensor module has been used to simulate various states of face position against the mask in order to better understand this issue. Of course, it should be noted that in this simulation, the finger is put in front of the sensor rather than a human face, but this makes no difference to the main issue.

The Red (abbreviated R) and Infrared (abbreviated IR) light spectrums are emitted by this sensor, and the sensor receives the light emitted by them. The MAX30102 sensor module is attached to the Arduino Uno board for this test, and the sensor reads the IR and R raw values to display them on the serial display.

As you can see, the IR and R values are approximately 125,000 and 107,000, respectively, when the finger is on the sensor and fully attached to it. However, when the finger moves away from the sensor, this value changes. In fact, it can be said that the IR and R values that the sensor reads depend on how close the finger is to it, and that the values of these two variables are known at specific distances as well. In this manner, it is possible to establish whether or not the person's face is attached to the sensor and, if so, how far away it is from the sensor (sealing cushion).

A large number of optical sensors are positioned on the surface of the air cushion, and each of them may have additional uses aside from their primary function, which is detecting the presence of a leak in the mask seal, including measuring the person's body temperature, heart rate, and blood gas saturation percentage. These side applications are described based on the analysis of various IR and R values from various angles. It is also possible that due to the various capabilities of the sensors, their technical specifications may also vary from one another (for instance, the wavelength of the light emitted from the sensors' LEDs may vary from one another), but in any case, the method of detecting leakage in the seal area will be the same in all sensors. Another illustration shows a tiny LED assembly (63) made up of two light-emitting diodes (61 ) and (62). This complex, which emits light at specific wavelengths, is situated on the surface of the air cushion that surrounds the nasal septum. The optical sensor (64) is positioned on the opposite side of the air cushion. So, this device might also serve as a pulse oximeter.

Fig. 7: Oxyhemoglobin and deoxyhemoglobin absorb red and infrared light differently, which is the basis for how pulse oximeters operate. At a wavelength of about 660 nm, one of the emitting diodes (61 ) emits light in the red spectrum; at this wavelength, deoxyhemoglobin has a higher optical absorption than oxyhemoglobin. At a wavelength of about 940 nm, another diode (62) emits infrared light, where Oxyhemoglobin absorbs more light than Deoxyhemoglobin. In order to determine the concentrations of Oxyhemoglobin and Deoxyhemoglobin, the micro-holder examines the absorption of light by tissues in each of the wavelengths and determines SpO ₂ . In addition to hypoxemia (lack of blood oxygen), it is also possible to detect other abnormalities such as carboxyhemoglobinemia or methemoglobinemia by using other wavelengths. The use of drugs like benzocaine, lidocaine, and prilocaine, as well as the ingestion of some chemicals like nitrates, are the causes of carboxyhemoglobinemia. Methemoglobinemia and CO gas poisoning are also contributing factors.

Fig. 8: The most important and necessary part of pulse oximeter absorption, which is necessary to determine SpO ₂ , is the AC part (alternating current) or pulsed arterial blood. This portion, which is initially absorbed, makes up a very small portion of the entire absorption spectrum. The DC component (direct current) is then calculated after this step. The picture makes it obvious that the tissue is where the majority of absorption takes place. Fig. 9: The following formula is used to calculate the percentage of blood oxygen saturation using a pulse oximeter:

The algorithms in the pulse oximeter then convert the value of R into the saturation percentage. These algorithms are developed in the processor using healthy volunteers as test subjects. Fig. provides an illustration of how to convert the R value to a percent saturation. In this example, R=1 , and SpO ₂ = 85%. is equivalent to R=1 based on measurements made previously on healthy individuals.

As was previously mentioned, in addition to its primary function, this sensor has the ability to measure body temperature. In order to achieve this, the sensor's LED set is temporarily turned off in accordance with a predetermined algorithm and timing, and the light-receiving sensor measures the user's body temperature by absorbing and processing heat waves that are emitted by the body.

The area where the air leakage has occurred will be displayed on the mobile phone or smart watch's screen after the system has detected the leak and sent a warning signal to the smart watch or mobile phone.

Fig. 10a: Depending on the type of sensors used in the mask, there may be different ways to display the leak's location. The first method is better suited for resistive touch sensors; in this method, each sensor's location on the mask as well as its pattern and shape are graphically displayed on the smart watch screen. For instance, in this visualization, the air cushion's surface is covered with seven resistive touch-sensitive sensors, allowing the shape of the cushion to be graphically divided into seven distinct areas and displayed; The sensors (100, 120, 130) in this visualization have detected leakage, and the entire areas (101 , 121 , 131 ) where these sensors are located have been marked for display and user warning.

Fig. 10b: The next display method is better suited for capacitive, optical, and proximity touch pressure sensors because it shows the mask pattern in white on the smartphone or smartwatch and determines where the leak is by how much pressure is applied. It is shown to the pressure sensors or the optical sensors as a series of colors with various contrasts, depending on how far the face is from the mask. If gray is used in the image, for instance, the point with more pressure will be shown in light gray, while the point with less pressure and a chance of leakage will be shown in dark gray. Other seal points will not be shown in the picture until they are in good condition.

Fig. 10c: If optical sensors are used, the smart watch can also display other vital signs such as heart rate, blood oxygen saturation percentage, or other blood gases, which is possible through the device menu. This is in addition to showing the state of the mask sealing. In this invention, it is also possible to display multiple parameters at once. One screen might show the seal status, blood oxygen saturation level, and heart rate, for instance.

Fig. 11 : The seal cushion (112) of this invention is made up of two components, 113 and 1 14. The first part, which is solid and made of silicone (1 13) and is placed on the second part, is both flexible and relatively hard. The sensors are also mounted on its surface, which comes into direct contact with the person's face. Under the first part (114), the second part is filled with a fluid similar to air and is empty like a bag. By inflating this component after the system has identified a leak, the seal will better fit the person's face by increasing the pressure between their face and the mask. Additionally, air is evacuated from this part if the sensors detect an excessive amount of pressure, which lowers the pressure between the mask and the person's face. The sealing cushion airbag may be one solid piece or split into two, three, or even more sections. The airbag is divided into two or three distinct areas by the inner walls in the visualization of the various models presented in this document, and each area has its own air inlet and is managed independently. This model only allows for the volume of the same part to change when air enters or exits, with the other parts remaining unchanged. When a leak is detected by a sensor, it is first determined in which area the sensor was located. We can list more management on various parts of the mask seal to fix leaks and holes among the benefits of this model over the integrated model. The system structure of multi-part cushions is depicted in block diagram form in Fig 11 a and 1 1 b. The air ducts are represented by lines 1 11 , and the parts are the various components of the air cushion in this system. All cushion components are connected to a single air pump, per the technical plan, but the air entry to each component is managed by a different solenoid valve. Two-way and normally closed solenoid valves are also present, along with a normally closed one-way solenoid valve and an air pressure sensor in the air transmission path.

The integrated cushion system structure is depicted in Fig. 1 1c. The two-way solenoid valve that was present in multi-part systems to regulate air entering various parts of the cushion has been removed in this system, which nonetheless functions similarly to multi-part systems.

The air pressure sensor prevents the cushion from over-inflating and damaging it, while a oneway solenoid valve is designed to release the air pressure of the cushions. Accordingly, a constant pressure is defined as the threshold pressure, and when the air pressure of each cushion reaches the threshold value, the one-way solenoid valve is opened and the pressure is discharged. Additionally, this sensor will be used as an additional tool for managing the mask seal condition.

Fig. 12: Through the assembly 131 and interface 140, the air created by the air pump will enter the air and signal terminal 14, where it will then pass through tubes in the body 121 to reach the various components of the air cushion.

Fig. 1 and Fig. 13: The set (131 ) has been used to transmit the signal from the terminal located in the body (14) to the transducer as well as to transmit the air from the air pump to the seal cushion. The signal from the sensors is transmitted by the printed circuit in the inner part of the mask body (13) to the terminal located in the body (14). The number of thin tubes in this set (132) (which varies depending on the number of components in the sealing cushion) and the signal transmission wires (133) are arranged next to one another. This set has a fixed connection at one end to the terminal (14) and another end to the interface (140). The case 130 is also connected to the interface's second component, part 141 . Due to the fact that this case (130), which is intended to be placed on the neck, is attached to the person, it contains electrical and electronic systems and circuits. Some vital parameter measurement sensors, such as a temperature sensor or a pulse sensor, may also be attached to the case's surface. Fig. 14: Bell interface (141 ) and spigot interface (140) make up the two parts of the signal and air interface set. The front of the threaded nut (142) places the end of the spigot interface (140), which is connected to the air and signal transmission assembly (131 ). The function of this nut, which is attached to the bell interface's threaded piece (143), is to hold the interface's two ends together.

A number of electrodes 144 and one or more connectors 145 for attaching the air transfer tubes to one another are present on the inner surfaces of both interfaces. One of the air connectors (146) is made in such a way that the two ends of the connector can only be closed to each other in one specific direction, making it impossible to connect the connector in any other directions. Each of the signal transmission electrodes (144) transmits the signal of a particular sensor to the transducer, and moving and closing the two ends of the interface to each other will result in errors and malfunctions of the mask.

Fig. 12: When filters of various standards, such as FFP2, FFP3, and others, are placed in the designated location on a portion of the mask's surface (122), the mask will perform as intended. After using the mask and at the end of their useful lives, the filters (122) can be replaced because of the clever design of their placement. Additionally, the frame 123 will cover the filters and other devices that are mounted on the mask body, such as the air transfer tubes (121 ), to maintain the mask's aesthetic appeal. This frame (123) does not fit with the body when it is attached to the mask because it is attached too far from the mask's edges. Air will be able to enter and exit from the edges of the mask in this way.