JP6944088B1 - Contamination mask and its control method - Google Patents

Abstract

Contamination masks with active fans utilize optical sensors to detect the rotation of the fan and the speed of rotation during the rotation of the fan. The detection of the respiratory cycle and / or the automatic on and / or off function of the fan is performed based on the analysis of the signal of the optical sensor. The use of optical sensors provides a low cost, compact way to implement automatic control functions. Detection is based on optical analysis of fan rotation rather than analysis of electrical fan signals, thus avoiding the need for any particular fan design.

Description

The present invention relates to a contaminated mask, the contaminated mask is for supplying filtered air to the wearer of the mask, the flow of which is assisted by a fan.

The World Health Organization (WHO) estimates that 4 million people die each year from air pollution. Part of this problem is the quality of the outside air in the city. The worst class is Indian cities like Delhi, which have annual pollution levels more than 10 times the recommended levels. Beijing is well known, with an annual average of 8.5 times the recommended safety level. However, even in European cities such as London, Paris and Berlin, it is higher than the WHO recommended level.

This problem does not improve significantly in a short period of time, so the only way to deal with this problem is to wear a mask that provides cleaner air by filtration. One or two fans are added to the mask to improve comfort and effectiveness.

The advantage for the wearer using the electric mask is that the lungs are released from the slight burden caused by inhalation against the resistance of the filter in conventional non-electric masks.

In addition, in conventional non-electric masks, inhalation also causes a slight negative pressure in the mask, which leads to the leakage of contaminants into the mask, which is dangerous if they are toxic substances. Indicates that there is. The electric mask delivers a stable airflow to the face, applying a slight positive pressure, for example determined by the resistance of the exhalation valve, to ensure that any leak is outward rather than inward.

There are several advantages when the operation or speed of the fan is adjusted. It can be used to improve comfort by better ventilation during the inhalation and exhalation sequence, or it can be used to improve electrical efficiency. The latter leads to extended battery life or enhanced ventilation. Both of these aspects require improvement in the current design.

To adjust the speed of the fan, the pressure in the mask is measured and both pressure fluctuations and pressure are used to control the fan.

For example, the pressure in the mask is measured by a pressure sensor and the fan speed can be varied depending on the sensor's measurements, such as based on detecting the inspiratory and expiratory phases. Pressure sensors are costly and it is desirable to provide an alternative method.

Since the fan-operated mask is a battery-powered device, it is desirable to minimize costs and power consumption. One problem is that the fan is left on when the mask is not worn, which results in unnecessary power consumption. It is possible to provide a dedicated sensor to detect when the mask is being worn, but this increases the cost of the respiratory mask.

When wearing a mask, the user typically switches on and turns on the fan. This switch increases the cost of the mask and is inconvenient to take up space and switch on. The ability to automatically switch on electronic devices avoids these drawbacks. However, this generally also requires a dedicated sensor to detect the use of the mask.

Therefore, it is desirable to find a lower cost solution, at least to provide an automatic on and / or off function based on, for example, detecting whether a mask is worn or not.

The present invention is defined by the claims.

According to an example according to certain aspects of the invention.
Air chamber,
A fan for sucking air into the air chamber from outside the air chamber and / or sucking air out of the air chamber from inside the air chamber.
An optical sensor for detecting the rotation of the fan and detecting the rotation speed during the rotation of the fan, and a contamination mask having a controller are provided, and the controller is based on the analysis of the optical sensor signal. hand,
It is configured to perform the automatic on and / or off function of the fan and / or to detect the user's respiratory cycle.

The present invention relates to a contamination mask. This means a device whose main purpose is to filter the ambient air breathed by the user. This mask does not treat any form of patient. In particular, the pressure levels and flows generated by the operation of the fans help to provide comfort (by simply affecting the temperature or relative humidity in the air chamber) and / or considerable additional breathing effort by the user. It is intended to help provide a flow across the filter without the need for. This mask does not provide overall respiratory support compared to when the user is not wearing the mask.

The fan may be for providing increased pressure in the air chamber (eg, flow into the air chamber during suction). In such cases, it is only necessary to provide a slightly increased pressure, for example to assist the user's inhalation.

Alternatively, the fan may simply draw air from the inside of the air chamber to the outside of the air chamber. In this way, the fan can facilitate the delivery of fresh filtered air to the air chamber, even during exhalation, which enhances user comfort. In this case, for example, the pressure in the air chamber may always be lower than the external pressure (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 high, the pressure is still higher than the ambient pressure.

Therefore, there are different possible intended fan functions.

The use of optical sensors provides a low cost and compact way to perform auto-on and / or auto-off functions. The detection is based on an optical analysis of fan rotation rather than an analysis of the electrical fan signal, thus avoiding the need for any particular fan design.

The controller is configured to perform an automatic control function.

This automatic control function has an automatic fan on function based on detecting the rotation of the fan caused by the user's breathing while the fan is not running. Thus, only the optical sensor needs to be powered to detect fan rotation, and the user's respiration causes enough fan movement to be detected.

The controller is configured to operate in a discontinuous light detection mode, for example when the fan is turned off. This saves power.

The automatic control function performed by the controller may be a fan automatic off function based on detecting a constant fan speed.

This constant speed indicates that the mask is not worn.

By deciding whether or not the mask is worn, the mask design makes it possible to save power. In particular, if the fan speed is not modulated by the user's breathing, it indicates that the mask is not worn. The fan may be turned off when it is detected that the mask is not worn.

The automatic control function performed by the controller may detect the user's respiratory cycle, for example based on detecting changes in fan speed over time.

In this way, the fan can be controlled based on the user's breathing pattern. In addition or instead, the outlet valve may be controlled depending on the phase of the respiratory cycle, or the fan may be turned off during the inhalation time. It is used to save power. Stopping the fan during inhalation, when configured as such, saves power and is desirable for users who do not have difficulty breathing through the filter.

The controller may be configured to detect the user's respiration frequency based on detecting changes in fan speed over time and to control the fan depending on this respiration frequency. The speed of this fan increases, for example, if the user is breathing faster, which indicates that the user is exercising.

The mask may further comprise a filter that directly forms a boundary between the air chamber and the surrounding environment outside the air chamber. Therefore, the user breathes through the filter. This filter constitutes the outer wall of the air chamber.

The filter directly forms a boundary between the air chamber and the surrounding environment outside the air chamber. This provides a compact configuration that avoids the need for flow transport aisles. This means that the user can breathe through the filter. The filter may have multiple layers. For example, the outer layer (eg, the cloth layer) may form the body of the mask and the inner layer may be for removing finer contaminants. The inner layer may be removable for cleaning or replacement, but both layers filter together in that air can pass through the structure and that the structure serves a filtering function. It may be considered to constitute.

Therefore, the filter preferably comprises an outer wall of the air chamber and optionally one or more other filter layers. This provides a particularly compact configuration and allows for a larger filter area, as the body of the mask acts as a filter. Therefore, when the user inhales, ambient air is supplied directly to the user through the filter.

The mask can further have an outlet valve for the controllable exhaust of the air chamber to the outside, or an inlet valve for taking air into the air chamber from the outside, which valve is a passive pressure regulating check valve. Alternatively, it has an electrically controllable valve that is actively driven.

This is used to make the mask more comfortable. Closing the valve (actively or passively) during inhalation prevents unfiltered air from being inhaled. During exhalation, the valve is opened to release the exhaled air.

The optical sensor is
A light source and a photodetector sandwiching the fan, or a light source and a photodetector on one side of the fan, and a reflector on the fan can be included.

Therefore, there are different options for optical sensors.

The present invention also provides a non-therapeutic method of controlling a contamination mask, which method is:
A step of sucking air into the air chamber from outside the air chamber and / or sucking air out of the air chamber from inside the air chamber using a fan.
Based on the steps of using an optical sensor to detect the rotation of the fan and to detect the rotation speed during rotation, and the analysis of the detected rotation.
It has a step of performing an automatic on and / or off function of the fan and / or a step of detecting the user's respiratory cycle.

The method is
The fan by detecting the rotation of the fan caused by the user's breathing while the fan is not running to perform the automatic on function of the fan and / or by detecting a constant fan speed. Has a step to implement the automatic off function of.

The method is
Detecting the user's respiratory frequency based on detecting changes in fan speed over time and / or detecting changes in fan speed over time And it has a step of controlling the fan depending on the respiration frequency.

The present invention also provides a computer program that includes computer program code means configured to perform the methods specified above when the computer program is executed on the computer.

Examples of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a face mask in which fan rotation is detected. FIG. 2 shows an example of the components of the system of FIG. FIG. 3 shows a typical waveform of an optical sensor signal. FIG. 4 shows various possible patterns of light intensity. FIG. 5 is used to illustrate the auto-on function. FIG. 6 is used to illustrate the auto-off feature. FIG. 7 shows how the mask works.

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

While the detailed description and specific examples provide exemplary examples of devices, systems and methods, they are for illustration purposes only and are not meant to limit the scope of the invention. I want you to understand. These and other features, aspects and advantages of the devices, systems and methods of the present invention will be well understood from the following description, the appended claims and the accompanying drawings. It should be understood that the drawings are merely schematic and are not drawn to a certain scale. It should be understood that the same reference numbers are used throughout the drawings to indicate the same or similar parts.

The present invention provides a fouling mask with an active fan that utilizes the rotation of the fan and an optical sensor to detect the rotation speed during the rotation of the fan. Respiratory cycle detection and / or fan auto-on and / or off functions are performed based on the analysis of optical sensor signals. The use of optical sensors provides a low cost, compact way to implement automatic control functions. The detection is based on an optical analysis of fan rotation rather than an analysis of the electrical fan signal, thus avoiding the need for any particular fan design.

Therefore, the automatic control function is based on detecting the user's respiratory characteristics from the optical analysis of fan rotation. These respiratory characteristics include, for example, whether the user is breathing into the mask and / or the timing of the user's inspiration and expiration.

FIG. 1 shows a face mask in which fan rotation is detected.

A subject 10 wearing a face mask 12 covering the nose and mouth of the subject 10 is shown. The purpose of the mask is to filter the air before it is inhaled by the subject. For this purpose, the mask body itself acts as an air filter 16. Air is sucked into the air chamber 18 formed by the mask by suction. In one example, during suction, 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 only of the main body of the mask, or may have a plurality of layers. For example, the mask body has an outer cover formed from a porous woven material that acts as a prefilter. Inside the outer cover, a finer filter layer is reversibly attached to the outer cover. The finer filter layer may then be removed for cleaning and replacement, while the outer cover may be cleaned, for example by wiping. The outer cover also performs a filtering function, for example, to protect a finer filter from large debris (eg, mud), whereas this finer filter filters fine particles. There may be more layers than two layers. Together, these numerous layers act as an overall mask filter.

For example, when using an exhalation fan, when the subject exhales, air is exhausted through the outlet valve 22. This valve opens, allowing easy exhalation, but closes during inhalation. The fan 20 assists in discharging air through the outlet valve 22. Preferably, more air is removed than is exhaled so that more air is supplied to the face. This increases comfort by reducing relative humidity and cooling. Closing the valve during inhalation prevents unfiltered air from being inhaled.

Therefore, the timing of the outlet valve 22 depends on the subject's respiratory cycle. The outlet valve may be a simple passive check valve that operates by a pressure difference sandwiching the filter 16. However, an electronically controlled valve may be used instead.

When the mask is worn, the pressure in the closed chamber changes as a function of the subject's respiratory cycle. When the subject exhales, a slight increase in pressure occurs, and when the subject inhales, a slight decrease in pressure occurs.

When a fan is driven at a constant drive level (ie, voltage), there are different pressure drops across the fan, so different prevailing pressures appear as different loads on the fan. This modified load results in different speeds of the fan.

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

FIG. 2 shows an example of system components. The same components as in FIG. 1 are given the same reference numbers.

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

The fan 20 has a set of fan blades 20a and a fan motor 20b. In one example, the fan motor 20b is a brushless motor that is electronically rectified.

The optical sensor 24 has a light source 24a on one side of the fan blade and a photodetector on the opposite side of the fan blade. Therefore, when there is a gap between the fan blades, the light reaches the detector, and if there is a fan blade in that space, the light is blocked.

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

Therefore, by monitoring this time period, the speed of the fan can be monitored. This also allows the fan load to be monitored, which is different between inspiration and exhalation when the mask is worn, but more when the mask is not worn. It is constant. For example, in the case of an exhalation fan, the air flow exhaled during exhalation increases the rotation speed of the fan, resulting in an increase in frequency. During inspiration, the fan speed decreases (compared to exhalation).

FIG. 4 shows various possible patterns of light intensity.

FIG. 4A shows a completely off state in which the optical sensor is turned off and there is no signal from the optical sensor.

FIG. 4B shows the light intensity during inspiration.

FIG. 4C shows the light intensity during exhalation given a faster fan speed than inspiratory (eg, exhaled fan).

FIG. 4 (D) shows how the frequency (corresponding to the reciprocal of the time period T in FIG. 3) changes over time during normal respiration.

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

However, in addition, automatic adjustment of fan rotation may be performed according to the breathing pattern (ie, inspiration and expiration). In addition, on-demand airflow delivery may be performed as the user's activities, such as sitting, walking, running, and biking.

These features provide the consumer with a fully customized experience and meet consumer needs for comfort, adequate airflow and power savings under a variety of user scenarios.

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

From time t ₀ to t ₁ , the fan is off and the mask is not worn, so there is no fan rotation.

The user wears a mask from the time t _1. Here, the user's breathing causes the fan to rotate. For example, the user is required to breathe into the fan and the fan rotation begins to be detected. The optical sensor performs periodic measurements, the rotation of the fan is detected at time t _2. The fan is then turned on and persists without the user having to breathe into the fan.

Thus, auto-on function of the fan, the fan is while not running (time t ₁ earlier), based on detecting the rotation of the fan caused by respiration of the user, when the fan is turned off, discontinuous There is a light detection mode.

This discontinuous detection mode provides power savings and is present in an off or standby state. For example, the sensor wakes up every few seconds, such as 2 seconds, 4 seconds or more.

FIG. 6 is used to illustrate the auto-off feature.

From time t ₀ to t ₁ , the fan is on and the mask is worn. Since the rotation speed of the fan follows a cycle that depends on the user's breathing pattern, there is a maximum frequency f _max and a minimum frequency f _min .

This represents the normal operation of the mask, which is defined as a continuous mode, during 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 driving, but there is no longer any modulation of fan speed caused by the user's breathing. This change is detected and the fan is turned off.

For example, during normal use, a fan rotation cycle, such as 4 seconds, 8 seconds, is recorded and the frequency during this cycle is calculated. The maximum and minimum frequencies _{of f max} and f _min during this cycle are determined.

The difference value f _max −f _min is then compared to a pre-determined threshold value f _{threshold based on actual testing.}

When the difference value f _max −f _min is smaller than the threshold value f _threshold , it means that respiration is not detected, and an OFF signal is sent to the controller to turn off the fan.

The fan auto-off feature is based on detecting a constant fan speed.

As mentioned above (and as most clearly shown in FIGS. 4 and 6), the breathing pattern changes the rotational speed of the fan.

This means that optical detection is used to detect the respiratory cycle, i.e. inhalation and exhalation timing.

If an electronically switched outlet valve is used, then respiratory cycle timing information is used to control the outlet valve 22 depending on the phase of the respiratory cycle. In addition to controlling the outlet valve, the controller turns off the fan during inhalation or expiration time.

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

The light source of the optical sensor can take any suitable form. One example is to use an existing light output indicator so that there is no extra component cost. Small, low-cost photodetectors are also available.

FIG. 2 shows a light source and detector sandwiching a fan, but to provide a more compact configuration, a reflective fan blade or reflective pad applied to the fan blade so that the light source and detector are on the same side. May be used.

As a further alternative, light guides may be used to direct light from a light source (eg, mounted on the top of the PCB) to the area of the fan blades. At this time, the photodetector either directly detects the light or detects the reflected light. The light guide emits radial inward light from the radial outside of the fan blade, which in turn reflects the radial inward light to a detector (eg, on the bottom of the PCB). May be good. The light source may have other functions, such as an ON indicator, and the light guide simply extracts a portion of the output light for use as detection light.

The fan is usually a centrifugal fan or an axial fan.

FIG. 7 shows how the mask operates, and this method is
In step 70, the step of sucking air into the air chamber from the outside of the air chamber and / or sucking air from the inside of the air chamber to the outside of the air chamber using a fan .
Based on the step of detecting the rotation of the fan in step 72 and detecting the rotation speed during rotation, and the analysis of the detected rotation in step 74, the automatic on and / or off function of the fan is performed. Have a step to do.

The method is
Based on detecting changes in fan speed over time in step 76, and / or based on detecting changes in fan speed over time in step 78. It also has a step of detecting the user's respiration frequency and controlling the fan depending on the respiration frequency.

It can be seen that the present invention may be utilized in many different mask designs, including fanned inspiratory or expiratory, and an air chamber or sealed air chamber formed by a filter membrane.

Therefore, one option, as described above, is the use of a fan solely to draw air from the inside of the air chamber to the outside of the air chamber, for example when the exhaust valve is open. In such cases, the pressure within the mask volume is maintained below the external atmospheric pressure by the fan so that there is a final flow of clean filtered air into the mask volume during exhalation. .. Therefore, lower pressure may be evoked by the fan during exhalation and by the user during inspiration (when the fan is turned off).

An alternative option is the use of a fan solely to draw air into the air chamber from the ambient environment. In such cases, the fan operates to increase the pressure in the air chamber, but the maximum pressure in the air chamber in use is higher than the pressure outside the air chamber, especially since high pressure assisted breathing is not intended. Also keeps high below ₄ cmH 2 O. Therefore, a low power fan may be used.

In all cases, preferably, the pressure in the air chamber is above the external atmospheric pressure, 2 cmH less than ₂ O, 1 cmH less than ₂ O, or 0.5cmH remains below ₂ O. Therefore, the contaminating mask is not intended to be used to provide sustained positive airway pressure, not to treat the patient.

The mask is preferably battery operated, as low power operation is of particular interest.

As mentioned above, the embodiments utilize controls implemented in a number of ways, along with software and / or hardware, to perform the various functions required. A processor is an example of a controller that uses one or more microprocessors programmed with software (eg, microcode) to perform the required function. However, the controller may be implemented with or without a processor, dedicated hardware for performing some functions, and a processor (eg, one or more) for performing other functions. May be implemented in combination with the programmable microprocessor and related circuitry).

Examples of controller components used in the 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 practices, the processor or controller may be associated with one or more storage media, such as volatile and non-volatile computer memories such as RAM, PROM, EPROM and EEPROM. The storage medium may be encoded by one or more programs that perform the required functions when executed on one or more processors and / or controllers. The various storage media may be mounted within the processor and / or controller, or may be transportable such that one or more programs stored on the storage medium are loaded into the processor or controller. ..

Other modifications to the disclosed examples may be understood and implemented by those skilled in the art in practicing the present invention from the drawings, the present disclosure and the examination of the appended claims. In the claims, the term "having" does not preclude other elements or steps, and does not preclude the existence of a plurality of elements without stating that there are a plurality of elements. The mere fact that certain means are described in different dependent claims does not indicate that the combination of these means cannot be used in an advantageous manner. No reference code in the claims should be construed as limiting its scope.

Claims (15)

Air chamber,
A fan for sucking air into the air chamber from outside the air chamber and / or sucking air out of the air chamber from inside the air chamber.
In an optical sensor for detecting the rotation of the fan and detecting the rotation speed during the rotation of the fan, and a contamination mask having the controller, the controller is based on the analysis of the signal of the optical sensor. ,
A pollution mask configured to perform automatic fan on and / or off functions and / or to detect the user's respiratory cycle. 1. The controller is configured to perform an automatic on function of the fan based on detecting the rotation of the fan caused by the user's breathing while the fan is not running. The mask described in. The mask of claim 2, wherein the controller is configured to operate in a discontinuous light detection mode when the fan is turned off. The mask according to any one of claims 1 to 3, wherein the controller is configured to perform an automatic off function of the fan based on detecting a constant fan speed. The mask according to any one of claims 1 to 4, wherein the controller is configured to detect a user's respiratory cycle based on detecting changes in fan speed over time. The controller is configured to detect a user's respiration frequency based on detecting a change in fan speed over time and control the fan depending on the respiration frequency. The mask according to any one of 5 to 5. The mask according to any one of claims 1 to 6, further comprising a filter that directly forms a boundary between the air chamber and the surrounding environment outside the air chamber. The mask according to claim 7, wherein the filter constitutes an outer wall of the air chamber. The fan is for sucking air from the inside of the air chamber to the outside of the air chamber, or for taking air into the air chamber from the outside of the air chamber, claims 1 to 8. The mask according to any one of the above. It further comprises a valve for controllingly exhausting the air chamber to the outside or for taking air into the air chamber from outside the air chamber, the valve being a passive pressure regulated check valve or active. The mask according to any one of claims 1 to 9, which comprises an electrically controllable valve that is driven in a positive manner. The optical sensor is
The mask according to any one of claims 1 to 10, further comprising a light source and a photodetector sandwiching the fan, or a light source and a photodetector on one side of the fan, and a reflector on the fan. In a non-therapeutic way to control contamination masks,
A step of sucking air into the air chamber from outside the air chamber and / or sucking air out of the air chamber from inside the air chamber using a fan.
Perform automatic on and / or off functions of the fan based on the steps of using an optical sensor to detect the rotation of the fan and to detect the rotation speed during rotation, and the analysis of the detected rotation. A non-therapeutic method of controlling a contaminating mask that has steps to detect and / or detect the user's respiratory cycle. The step of performing the automatic on function of the fan by detecting the rotation of the fan caused by the user's breathing while the fan is not running, and / or by detecting a constant fan speed. 12. The method of claim 12, comprising the step of performing an automatic fan off function. Detecting the user's respiratory frequency based on detecting changes in fan speed over time and / or detecting changes in fan speed over time The method according to claim 12 or 13, wherein the fan is controlled depending on the respiration frequency. A computer program having computer program code means configured to perform the method of any one of claims 12-14 when executed by the controller of claims 1-11.

Images