阅读说明：本技术 防污染面罩及控制方法 (Anti-pollution mask and control method ) 是由 孔涛 陈伟忠 于 2019-09-19 设计创作，主要内容包括：有源风扇辅助防污染面罩利用光学传感器来检测风扇的旋转,并在风扇旋转期间检测旋转速度。基于对光学传感器信号的分析,实现呼吸循环检测和/或风扇的自动开启和/或关闭功能。光学传感器的使用提供了低成本和紧凑的方式来实现自动控制功能。由于检测是基于风扇旋转的光学分析而不是风扇电信号分析,因此它不需要任何特定的风扇设计。(Active fan-assisted antipollution masks utilize optical sensors to detect rotation of the fan and to detect rotational speed during fan rotation. Based on the analysis of the optical sensor signal, a breathing cycle detection and/or an automatic on and/or off function of the fan is achieved. The use of optical sensors provides a low cost and compact way to implement automatic control functions. Since the detection is based on optical analysis of the fan rotation and not on electrical fan signal analysis, it does not require any specific fan design.)

1. An anti-contamination mask comprising:

an air chamber (18);

a fan (20) for drawing air into the air chamber (18) from outside the air chamber and/or from inside the air chamber to the outside;

an optical sensor (24) for detecting rotation of the fan and detecting a rotational speed during fan rotation; and

a controller (30) adapted to, based on an analysis of the signal of the optical sensor:

the automatic opening and/or closing function of the fan is realized; and/or

A breathing cycle of the user is detected.

2. The mask according to claim 1, wherein the controller (30) is adapted to enable an automatic turn-on function of the fan based on detecting a rotation of the fan caused by a user's breathing without activating the fan.

3. The mask according to claim 2, wherein the controller (30) is adapted to operate in a discontinuous optical sensing mode when the fan is off.

4. The mask according to any one of claims 1 to 3, wherein the controller (30) is adapted to implement an automatic shut down function of the fan based on detecting a uniform fan speed.

5. The mask according to any one of claims 1 to 4, wherein the controller (30) is adapted to detect the breathing cycle of the user based on detecting a change in fan speed over time.

6. The mask according to any one of claims 1 to 5, wherein the controller (30) is adapted to: detecting a breathing frequency of the user based on detecting a change in fan speed over time, and controlling the fan in accordance with the breathing frequency.

7. The mask according to any one of claims 1 to 6, further comprising a filter (16) forming a boundary directly between the air chamber and an ambient environment outside the air chamber.

8. The mask of claim 7, wherein the filter comprises an outer wall (16) of the air chamber.

9. The mask according to any one of claims 1 to 8, wherein the fan (20) is for drawing air from inside the air chamber to the outside or for drawing air from the outside to inside the air chamber.

10. The mask according to any one of claims 1 to 9, further comprising a valve (22) for controllably venting the air chamber (18) to the exterior or introducing air from the exterior into the air chamber, wherein the valve (22) comprises a passive pressure regulating check valve or an actively driven electrically controlled valve.

11. The mask according to any one of claims 1 to 10, wherein the optical sensor (24) includes:

a light source (24a) and a light detector (24b) on opposite sides of the fan; or

A light source (24a) and a light detector (24b) on one side of the fan, and a reflector on the fan.

12. A non-therapeutic method of controlling a contamination mask, comprising:

(70) drawing air into an air chamber (18) from outside the air chamber and/or from inside the air chamber to the outside using a fan;

(72) detecting rotation of the fan using an optical sensor, and detecting a rotation speed during the rotation; and, based on the analysis of the detected rotation:

(74) to implement the automatic opening and/or closing function of the fan and/or

(76) A breathing cycle of the user is detected.

13. The method of claim 12, comprising:

implementing an automatic turn-on function of the fan by detecting fan rotation caused by a user's breath when the fan is not activated; and/or

The automatic shut-down function of the fan is realized by detecting a uniform fan speed.

14. The method according to claim 12 or 13, comprising:

(76) detecting the breathing cycle of the user based on detecting a change in fan speed over time; and/or

(78) Detecting a breathing frequency of the user based on detecting a change in fan speed over time, and controlling the fan in accordance with the breathing frequency.

15. A computer program comprising computer program code means adapted to perform the method of any one of claims 12 to 14 when said program is run by a controller according to claims 1-11.

Technical Field

The present invention relates to an anti-contamination mask for providing filtered air to a wearer of the mask under an airflow assisted by a fan.

Background

The World Health Organization (WHO) estimates that 400 million people die of air pollution each year. Part of this problem is the outdoor air quality in cities. The worst in this category is the indian city, such as dely, whose annual pollution level exceeds 10 times the recommended level. It is well known that the annual average safety level in Beijing is 8.5 times the recommended safety level. However, even in european cities such as london, paris, and berlin, this level is higher than the recommendations of the world health organization.

Since this problem does not improve significantly in the short term, the only way to solve this problem is to wear a mask that can provide cleaner air by filtration. To improve comfort and effectiveness, one or two fans may be added to the mask.

The benefit to the wearer of the use of a powered mask is that the lungs are relieved of the slight tension caused by inhalation against the resistance of the filter in a conventional unpowered mask.

In addition, in conventional non-powered masks, inhalation also causes a slight negative pressure within the mask, resulting in leakage of contaminants into the mask, which may prove dangerous if the contaminants are toxic substances. The powered mask delivers a steady flow of air to the face and may, for example, provide a slight positive pressure (as may be determined by the resistance of the exhalation valve) to ensure that the leak is outward rather than inward.

There are several advantages if the operation or speed of the fan is adjusted. This may be used to improve comfort by more appropriate ventilation in inhalation and exhalation sequences, or may be used to increase electrical efficiency. The latter means longer battery life or increased ventilation. Both of these aspects require improvement in current designs.

To adjust the fan speed, the pressure inside the mask can be measured and both the pressure and the pressure change can be used to control the fan.

For example, the pressure inside the mask may be measured by a pressure sensor, and the fan speed may be varied based on the measurements of the sensor, e.g. based on detecting inhalation and exhalation phases. Pressure sensors are expensive and it is therefore desirable to provide an alternative approach.

Fan operated masks are battery operated devices and it is therefore desirable to reduce power consumption to a minimum while keeping costs to a minimum. One problem is that when the mask is not worn, the fan may remain on, which may result in unnecessary power consumption. Sensors dedicated to detecting when the mask is worn may be provided, but this increases the cost of the breathing mask.

When wearing the mask, the user typically activates a switch to turn on the fan. This switch adds cost to the mask, takes up space and is inconvenient to switch on. The automatic electronic switch-on function will avoid these drawbacks. However, this also typically requires a dedicated sensor to sense the use of the mask.

It is therefore desirable to find a low cost solution at least for providing an automatic opening and/or closing function, e.g. based on detecting whether a mask is worn.

Disclosure of Invention

The invention is defined by the claims.

According to an example of one aspect of the present invention, there is provided a contamination prevention mask, including:

an air chamber;

a fan for drawing air into the air chamber from outside the air chamber and/or drawing air out of the air chamber from inside the air chamber.

An optical sensor for detecting rotation of the fan and detecting a rotation speed during the rotation of the fan; and

a controller (30) adapted to, based on an analysis of the optical sensor signal:

the automatic opening and/or closing function of the fan is realized; and/or

A breathing cycle of the user is detected.

The invention relates to an anti-pollution mask. By this is meant a device whose main purpose is to filter the ambient air to be breathed by the user. The mask does not perform any form of patient handling. In particular, the pressure level and flow generated by the fan operation are used only to provide comfort (by affecting the temperature or relative humidity in the air chamber) and/or to assist in providing flow through the filter without requiring additional significant respiratory effort by the user. The mask does not provide overall breathing assistance compared to a situation where the user does not wear the mask.

The fan may be used to provide increased pressure in the air chamber (e.g., airflow into the air chamber during inhalation). In this case, only a small increased pressure needs to be provided, for example to assist the user's inspiration.

The fan may alternatively be used only to draw air from inside the air chamber to the outside. In this way, the supply of fresh filtered air to the air chamber may be facilitated even during exhalation, which improves the comfort of the user. In this case, the pressure in the air chamber may, for example, always be lower than the external (atmospheric) pressure, so that fresh air is always supplied to the face. However, during exhalation, if the fan speed is slow or the exhalation volume is large, the pressure may still be higher than ambient pressure.

Thus, the fans have different possible intended functions.

The use of an optical sensor provides a low cost and compact way to implement an auto-on function and/or an auto-off function. Since the detection is based on optical analysis of the fan rotation, rather than on analysis of the fan electrical signal, it does not require any specific fan design.

The controller is adapted to implement an automatic control function.

The automatic control function may include an automatic turn-on function of the fan based on detecting rotation of the fan caused by the user's breathing without activating the fan. In this way, the fan rotation can be detected simply by powering the optical sensor, and the user's breath will create sufficient fan motion to detect.

The controller is adapted to operate in a discontinuous optical sensing mode, for example, when the fan is off. This saves power.

The automatic control function implemented by the controller may be an automatic fan shut down function based on detecting a uniform fan speed.

This uniform velocity indicates that the mask is not being worn.

By determining whether the mask is unworn, the mask design may conserve power. In particular, if the fan speed is not adjusted by the user's breathing, it is an indication that the mask is not being worn. When it is detected that the mask is not being worn, the fan may be turned off.

The automatic control function implemented by the controller may for example be to detect the user's breathing cycle based on detecting a change in fan speed over time.

In this way, the fan can be controlled based on the breathing pattern of the user. Additionally or alternatively, the outlet valve may be controlled according to the phase of the breathing cycle, or the fan may be turned off during the inspiration time. This can be used to save nickname power. For a user who breathes through the filter without difficulty, it may be desirable to turn off the fan during inhalation to save power (if configured in this manner).

The controller may be adapted to detect a breathing frequency of the user based on detecting a change in the fan speed over time and to control the fan in accordance with the breathing frequency. For example, if the user breathes faster, the fan speed may be increased, which may indicate that the user is exercising.

The mask may also include a filter that forms a boundary directly between the air chamber and the ambient environment outside the air chamber. The user therefore breathes through the filter. The filter may include an outer wall of the air chamber.

The filter forms a boundary directly between the air chamber and the ambient environment outside the air chamber. This provides a compact arrangement which avoids the need for a traffic transmission channel. This means that the user can breathe through the filter. The filter may have multiple layers. For example, the outer layer may form the body of the mask (e.g., a fabric layer), while the inner layer may be used to remove finer contaminants. The inner layer may then be removable for cleaning or replacement, but the two layers may be considered together to constitute a filter, since air is able to pass through the structure and the structure performs a filtering function.

Thus, the filter preferably comprises the outer wall of the air chamber and optionally one or more further filter layers. This provides a particularly compact arrangement and enables a large filtering area, as the mask body performs the filtering function. Thus, when a user inhales, ambient air is provided directly to the user through the filter.

The mask may further comprise an outlet valve for controllably discharging the air chamber to the outside, or an inlet valve for introducing air from the outside into the air chamber, wherein the valve comprises a passive pressure regulating check valve or an actively driven electrically controlled valve.

This can be used to make the mask more comfortable. During inhalation, the inhalation of unfiltered air can be prevented by actively or passively closing the valve. During inspiration, the valve is opened, thereby expelling exhaled air.

The optical sensor may include:

a light source and a light detector on opposite sides of the fan; or

A light source and a light detector on one side of the fan, and a reflector on the fan.

Thus, the optical sensor has different options.

The present invention also provides a non-therapeutic method of controlling a contaminated face mask, comprising:

drawing air into the air chamber from outside the air chamber and/or drawing air into the air chamber from inside the air chamber to outside using a fan;

detecting rotation of the fan using an optical sensor and detecting a rotation speed during the rotation; and based on the analysis of the detected rotation:

the automatic opening and/or closing function of the fan is realized; and/or

A breathing cycle of the user is detected.

The method may include:

the automatic start function of the fan is realized by detecting the rotation of the fan caused by the breathing of the user when the fan is not activated; and/or

The automatic shut-down function of the fan is realized by detecting the uniform fan speed.

The method may include:

detecting a breathing cycle of the user based on detecting a change in fan speed over time; and/or

The breathing rate of the user is detected based on detecting a change in fan speed over time, and the fan is controlled in accordance with the breathing rate.

The invention also provides a computer program comprising computer program code means adapted to perform the above-mentioned method when said program is run on a computer.

Drawings

Examples of the invention will now be described in detail with reference to the accompanying drawings, in which:

FIG. 1 shows a mask in which fan rotation may be detected;

FIG. 2 illustrates one example of components of the system of FIG. 1; FIG. 3 shows a typical waveform of an optical sensor signal;

FIG. 4 illustrates various possible light intensity patterns;

FIG. 5 is used to illustrate the auto-on function;

FIG. 6 is used to illustrate the auto-close feature; and is

Figure 7 illustrates a mask operation method.

Detailed Description

The present invention will be described with reference to the accompanying drawings.

It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems, and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. It should be understood that the figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

An active fan assisted antipollution mask utilizes an optical sensor to detect rotation of a fan and to detect rotational speed during fan rotation. Based on the analysis of the optical sensor signal, a breathing cycle detection and/or an automatic on and/or off function of the fan is achieved. The use of optical sensors provides a low cost and compact way to implement automatic control functions. Since the detection is based on optical analysis of the fan rotation and not on electrical fan signal analysis, it does not require any specific fan design.

Thus, the automatic control function detects the user's breathing characteristics based on an optical analysis of the fan rotation. These breathing characteristics include, for example, whether the user is breathing into the mask, and/or their time of inspiration and expiration.

Fig. 1 shows a mask in which fan rotation can be detected.

A subject 10 is shown wearing a mask 12 that covers the nose and mouth of the subject. The mask functions to filter air prior to breathing the air. To this end, the mask body itself serves as the air filter 16. Air is drawn into the air chamber 18 formed by the mask by inhalation. In one example, during inhalation, the outlet valve 22, such as a check valve, is closed due to low pressure in the air chamber 18.

The filter 16 may be formed solely from the body of the mask or there may be multiple layers. For example, the mask body may include an outer cover formed from a porous textile material that acts as a pre-filter. Inside the housing, a relatively thin filter layer is reversibly attached to the housing. The finer filter layer can then be removed for cleaning and replacement, while the outer covering can be cleaned, for example, by wiping. The face mask also performs a filtering function, such as protecting the finer filter from large debris (e.g., dirt), which filters out fine particulate matter. There may be more than two layers. The multiple layers together act as an integral filter for the mask.

Taking the exhalation fan as an example, when the subject exhales, air is expelled through the outlet valve 22. This valve is opened to facilitate exhalation, but closed during inhalation. The fan 20 assists in expelling air through the outlet valve 22. Preferably, more air is removed than is exhaled so that additional air is supplied to the face. Comfort is increased due to reduced relative humidity and cooling. By closing the valve during inhalation, unfiltered air is prevented from being inhaled.

Thus, the timing of the outlet valve 22 depends on the subject's breathing cycle. The outlet valve may be a simple passive check valve operated by the pressure differential across the filter 16. However, it may be an electronically controlled valve.

When the mask is donned, the pressure within the enclosure will vary according to the subject's breathing cycle. When the subject exhales, the pressure will increase slightly, and when the subject inhales, the pressure will decrease slightly.

If the fan is driven at a constant drive level (i.e. voltage), the different prevailing pressures will cause different loads on the fan due to the different voltage drops across the fan. This varying load will then result in different fan speeds.

The present invention utilizes optical detection of the fan speed. An optical sensor 24 is provided for detecting the rotation of the fan and the rotational speed during the rotation of the fan.

FIG. 2 shows one example of system components. The same reference numerals are used for the same components as in fig. 1.

In addition to the components shown in FIG. 1, FIG. 2 also shows a controller 30 and a local battery 32, and also shows that the optical sensor 24 includes a light source 24a and a light detector 24 b.

The fan 20 includes a set of fan blades 20a and a fan motor 20 b. In one example, fan motor 20b is an electronically commutated brushless motor.

The optical sensor 24 includes a light source 24a on one side of the fan blade and a light detector on the opposite side of the fan blade. Thus, when there is a gap between the fan blades, light reaches the detector, and when the fan blades are in space, the light is blocked.

Fig. 3 shows a typical waveform of the optical sensor signal, expressed as light intensity versus time. The peaks of light intensity correspond to light passing through the gaps between the fan blades, while the valleys correspond to light blocked by the fan blades. The time period T represents the fan speed.

Thus, by monitoring the time period, the fan speed may be monitored. This in turn enables monitoring of the fan load, which is different from inhalation and exhalation when the mask is worn, while the fan load will be more constant when the mask is not worn. Taking the exhalation fan as an example, during exhalation, the rotational speed of the fan will increase due to the exhalation air flow, resulting in a higher frequency. During inspiration, the rotational speed of the fan will decrease (compared to expiration).

Fig. 4 shows various possible light intensity patterns.

Fig. 4(a) shows a fully off state, in which the light sensor has been turned off and there is no light sensor signal.

Fig. 4(B) shows the light intensity during inhalation.

Fig. 4(C) shows the light intensity during exhalation, with a faster fan speed compared to inhalation (in the case of an exhalation fan).

Fig. 4(D) shows how the frequency (corresponding to the inverse of the time period T in fig. 3) varies with time during normal breathing.

The present invention utilizes fan speed information to provide automatic fan control. The most basic function is an auto-on function or an auto-off function.

In addition, however, automatic adjustment of the fan rotation may be achieved according to the breathing pattern (i.e., inhalation and exhalation). In addition, on-demand airflow delivery may be achieved as a function of user activity (e.g., sitting, walking, running, cycling).

These functions can provide a fully customized experience for the consumer and meet their comfort, adequate air circulation, and energy savings needs in various user scenarios.

Fig. 5 is used to explain the automatic opening function.

From time t0 to t1, the fan is off and the mask is not being worn, so there is no fan rotation.

From time t1, the user dons the mask. There is a rotation of the fan caused by the user's breathing. For example, a user may be required to blow into a fan to begin detecting rotation of the fan. The optical sensor periodically performs a measurement so that the fan rotation is detected at time t 2. The fan is then turned on and continues to operate without the user blowing into the fan.

Thus, the automatic turn-on function of the fan is based on detecting fan rotation caused by the user's breath when the fan is not activated (before time t 1), and a possibly discontinuous optical sensing pattern when the fan is off.

The discontinuous sensing mode may save power and is present in both off or standby states. For example, the sensor wakes up every few seconds, e.g., 2 seconds, 4 seconds, or longer.

Fig. 6 is used to explain the auto-close function.

From time t0 to t1, the fan has turned on and the mask is worn. The fan speed follows a period dependent on the user's breathing pattern, so that there is a maximum frequency f_maxAnd minimum frequency f_min。

This represents normal operation of the mask, which may be defined as a continuous mode in which the optical sensor continuously records and processes the light intensity signal of the photodetector.

The user removes the mask at time t 1. The fan is still driven but there is no longer an adjustment in the fan speed caused by the user's breathing. This change is detected and the fan has been turned off.

For example, during normal use, the time period of fan rotation is recorded, e.g. 4 seconds or 8 seconds, and the frequency within this time period is calculated. During which the maximum and minimum frequencies f are determined_maxAnd f_min。

The difference f may then be compared_max-f_minWith a predetermined threshold f based on actual testing_{Threshold value}A comparison is made.

If the difference f_max-f_minLess than a threshold value f_{Threshold value}It means that no breathing is detected and an OFF signal is sent to the controller to turn OFF the fan.

Thus, the automatic shut down function of the fan is based on detecting a uniform fan speed.

As described above (best shown in fig. 4 and 6), the breathing pattern varies the speed of rotation of the fan.

This means that optical sensing can be used to detect the breathing cycle, i.e. inspiration and expiration times.

If an electronically switched outlet valve is used, then the breathing cycle timing information can be used to control the outlet valve 22 according to the phase of the breathing cycle. In addition to controlling the outlet valve, the controller may also turn off the fan during inspiration or expiration times.

The fan speed may also be used to monitor the activity level of the user. For example, when the frequency of the light intensity pattern increases and reaches a certain value, it may be determined that the user is performing a high intensity activity. The fan speed may be increased to further assist the user in breathing.

The light source of the optical sensor may take any suitable form. One example is that existing light output indicators can be used, so that there is no additional component cost. Small low cost photodetectors may also be available.

Fig. 2 shows the light source and detector on opposite sides of the fan, but a reflective fan blade or reflective pad applied to the fan blade may be used so that the light source and detector may be on the same side to give a compact arrangement.

As another alternative, a light guide may be used to transmit light from a light source (e.g., which may be mounted on top of a PCB) to the region of the fan blades. The light detector may then detect the light directly, or may detect the reflected light. The light guide may transmit light radially inward from the radially outer side of the fan blade, which may then reflect the radial light to a detector, such as on the bottom side of the PCB. The light source may have other functions, such as an "ON" indicator light that is ON, and the light guide simply derives some of the output light to be used as sensed light.

The fan is typically a centrifugal or axial fan.

Fig. 7 illustrates a method of operation of a mask, comprising:

in step 70, drawing air from outside the air chamber to the air chamber and/or drawing air from inside the air chamber to outside using a fan;

detecting the rotation of the fan in step 72, and detecting the rotation speed during the rotation; and is

In step 74, based on the analysis of the detected rotation, an automatic turning on and/or off function of the fan is implemented.

The method may further comprise:

in step 76, a breathing cycle of the user is detected based on detecting a change in fan speed over time; and/or

In step 78, the user's breathing rate is detected based on detecting a change in fan speed over time, and the fan is controlled according to the breathing rate.

It will be seen that the present invention can be applied to many different mask designs, with fan assisted inhalation or exhalation, and air chambers formed by filter membranes or sealed air chambers.

Thus, one option as described above is to use a fan only for drawing air from inside the air chamber to the outside, for example when the exhaust valve is open. In this case, the pressure inside the mask volume can be kept below the outside atmospheric pressure by a fan so that clean filtered air will flow into the mask volume net during exhalation. Thus, low pressure may be induced by the fan during exhalation and by the user during inhalation (when the fan may be off).

Another option is to use a fan only for drawing air from the ambient to the air chamber interior. In this case, the fan was operated to increase the pressure in the air chamber, but the maximum pressure in the air chamber in use was kept 4cmH higher than the pressure outside the air chamber₂O toIn particular because high pressure assisted breathing is not intended. Thus, a low power fan may be used.

In all cases, the pressure inside the air chamber is preferably kept below 2cmH above the external atmospheric pressure₂O, or even below 1cmH₂O or even less than 0.5cmH₂And O. Thus, the anti-contamination mask is not used to provide continuous positive airway pressure and is not a mask for delivering therapy to a patient.

The mask is preferably battery-driven, so low power operation is of particular concern.

As described above, embodiments utilize a controller that can be implemented in software and/or hardware in a variety of ways to perform the various functions required. A processor is one example of a controller that employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform the required functions. However, the controller may be implemented with or without a processor, and may also be implemented as a combination of dedicated hardware for performing some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) for performing other functions.

Examples of controller components that may be used in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, Application Specific Integrated Circuits (ASICs), and Field Programmable Gate Arrays (FPGAs).

In various implementations, a processor or controller may be associated with one or more storage media, such as volatile and non-volatile computer memory, such as RAM, PROM, EPROM and EEPROM. The storage medium may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform the desired functions. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. Although specific measures are recited in mutually different dependent claims, this does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope.