WO2017198238A1

WO2017198238A1 - Automatic wearable powered air purifying system and method

Info

Publication number: WO2017198238A1
Application number: PCT/CN2017/092985
Authority: WO
Inventors: Dongping Lin; Yong Liu
Original assignee: Zhejiang Lifemed Technology Co Ltd
Current assignee: Zhejiang Lifemed Technology Co Ltd
Priority date: 2016-05-20
Filing date: 2017-07-14
Publication date: 2017-11-23
Anticipated expiration: 2018-11-20

Abstract

An automatic portable air purifying system. It consists of a battery operated air source, an air purifying filter (114), a respiratory apparatus (116) for user and a respirator controller which can detect user's breath pattern and automatically adjust the purified flow to meet user breathing needs and improve the breathing comfort.

Description

Automatic Wearable Powered Air Purifying System and Method

BACKGROUND OF THE INVENTION

The present invention is in the technical field of respirator. More specifically, the present invention is in the technical field of powered air purifying respirator system. More particularly, the present invention is in the technical field of wearable powered air purifying respirator system.

Respirator is a device to help a person breathing. The present invention has additional functions, such as protecting a user from the inhalation of harmful particles in the air. In general, there are two types of respirators. One is a passive respirator； the other is active respirator. One example of passive respirator that protects a user from harmful particles is medical mask. The user respiration effort drives the air through the mask filtration material such that the harmful particles are removed from the inspired air to the user. With the increase of filtration functions of passive air purifying respirator system, the respiratory resistance increases. The additional imposed respiratory efforts limit the utility of passive respirator system by the elderly, infants, children, young adults, and users with respiratory disease, who may have weakening respiratory efforts.

SUMMARY OF THE INVENTION

The present invention is an automatic wearable air purifying system. It consists of a battery operated air pump system, an air purifying filter, a respiratory apparatus and a respirator controller which can detect the user’s breath pattern and automatically adjust the purified flow to meet user breathing needs and minimize power consumption.

It is desirable that the powered air purifying system working condition can be automatically adjusted according to user breathing pattern such that the imposed respiratory efforts is reduced, the power consumption is minimized and the pressure at the breathing apparatus will be maintained higher than ambient. In the presented invention, methods and systems will be described to meet the above desired performance.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a systematic view of an automatic wearable air purifying system of the present invention；

Fig. 2 is systematic view of the automatic respirator control system data processing.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the invention in more detail, Fig. 1 shows a preferred embodiment of an automatic wearable powered purifying system 110, which consists of an air pump system 112, an air purifying filter system 114, a user respiratory apparatus 116 and an automatic respirator control system 118. The air is pumped by the air pump system 112 through the air purifying filter system 114 to the user respiratory apparatus 116. The automatic respirator control system monitors the user respiratory effort and adjusts the working condition of the air pump system 36.

In more detail, still referring to the invention of Fig. 1, the air pump system 112 pumps the air from the ambient to a high pressure and generates required flow. In a preferred embodiment, the air purifying filter is at the downstream of air pump system and upper stream of the respiratory apparatus 116. In another embodiment, the air purifying filter is at the upper stream of air pump system. In such a configuration, the blower generated negative pressure relative to ambient, which draws the air through the air purifying filter. In another preferred embodiment, the air purifying filter integrates a heater and a humidifier, such that the air provided to user respiratory apparatus 116 is heated and humidified.

The air pump system 112 consists of an air blower, an electronic driven motor and an electronic motor driving system powered by a battery. In a preferred embodiment, the battery is rechargeable. In another embodiment, the battery is replicable. The electronic motor driving system drives the motor to follow the command reference generated by the automatic respirator control system 118.

Still referring to Fig. 1, the air purifying filter system 114 is a particle filter which has specific grade of filter efficiency. One attribute of the particle filter is that the resistance through the filter increases at higher filter efficiency. It will generate inspiratory resistance and expiratory resistance for users.

Still referring to Fig. 1, the user respiratory apparatus 116 is a device which delivers the purified air to the user. One preferred embodiment is a full face mask with a hose connected to the downstream of air purifying filter 114. Another preferred embodiment is a nasal mask which covers user’s nose. In the preferred embodiment, the pressure inside respiratory apparatus 116 is maintained at a higher pressure than ambient pressure during the full breathing cycle. The function of the user respiratory apparatus 116 is to prevent unfiltered ambient air from entering the user airway. The other function of the user respiratory apparatus 116 is to prevent the user recirculate the exhaled gas. In a preferred embodiment, user respiratory apparatus is installed with a fix orifice leaking port, such that the exhaled gas from user will be discharged from the port. In another preferred embodiment, a check valve is installed on the user respiratory apparatus 116. The single direction check valve functions such it opens when the pressure inside user respiratory apparatus 116 exceeds certain threshold above the ambient pressure. The threshold is predetermined by the mechanical design of the check valve. Another embodiment is that an electronic control exhalation valve is installed on user respiratory apparatus 116. In such an embodiment, the valve is actively controlled by the automatic respirator control system 118. It is shut off during the user inspiration effort. It is actively opened during the user’s exhalation effort. In another embodiment, the respiratory apparatus 116 is installed with a heat and moisture exchange (HME) , which is able to maintain the temperature and humidity of the purified air.

Still referring to Fig. 1, an automatic respirator control system 118 detects the user respiratory effort and adjusts the working condition of air pump system 112, based on the detection of user respiratory effort. The flow of delivered by the air pump system 112 and the pressure at the respiratory apparatus 116 changes with the user respiratory effort, which in turn can affect the air pump system, such that the blower speed, and driving current. The automatic respiratory control system 118 measures these signal change and adjusts working condition of the air pump system. The objectives of the adjustment are to minimize the imposed respiratory effort. When the user inhales, more flow is provided. When the user exhales, the pressure at the respiratory apparatus 116 is reduced at the respiratory apparatus 116.

Still referring to Fig. 1, the pressure inside the respiratory apparatus 116 is maintained at slightly above the ambient pressure throughout the breath cycle. The advantage of such design is that the ambient air cannot leak back to the user interface 116 to contaminate the purified air.

Fig. 2 shows a preferred embodiment for data processing flow of the automatic respirator control system 118. The data processing 220 consists of a user respiratory effort detection module 222, an air delivery control system 224, and a motor driving system 226.

Still referring in Fig. 2, the user respiratory effort detection module identifies the respiratory effort with sensor measurements from the respirators. The sensor measurements include one, multiple or none of the following sensors, current measurement from the air pump, and velocity measurement from the air pump, air pump flow measurement, blower differential pressure and pressure at the user respiratory apparatus 116. One preferred embodiment of the user respiratory effort detection 222 utilizes the pressure variation at the user respiratory apparatus 116. During the inspiration effort, the pressure at the user respiratory apparatus 116 will drop, whereas during the exhalation effort, the pressure at the user respiratory apparatus 116 will increase. By quantifying the pressure variation amplitude, rate and direction, the respiratory effort can be detected. In the second preferred method, the rate of previously detected respiratory efforts is used to predicate the onset of the upcoming respiratory efforts.

Still referring in Fig. 2, the air delivery control system 224 adjusts the air pump working condition based on the output of user respiratory effort detection module 222 and sensor measurements from the respirator. The sensor measurements include one, multiple or none of the following sensors, current measurement from the blower, and velocity measurement from the blower, blower flow measurement, blower differential pressure and pressure at the user respiratory apparatus 116. The objective of air delivery control system is to reduce the imposed respiratory effort on the user due to the respirator, minimize power consumption and ensure the pressure at the user respiratory apparatus 116 is maintained higher than the ambient. The air delivery control system 224 can adjust one or more than one of the following working parameter on blower motor driving circuit, driving voltage, driving current, and blower velocity. It is known that rate of changing of these working parameters is proportional to the power consumption of the air pump system. The air pump system will work at a time varying condition with different patient efforts. In one preferred embodiment, the optimal control is used to achieve these objectives.

The air delivery control system 224 of the automatic respiratory control system 118 monitors the battery life and operating history of the air pump system 112. The level of reduction on imposed respiratory effort of breath reduction and battery life can be balanced for different working scenario. In one scenario that the battery life is not constrained, the air delivery control system can minimize imposed respiratory effort by adjusting blower control parameter more rapidly. In another scenario that the extended battery life is required, the air delivery control system can minimize the blower control parameter adjustment and maintain the pressure of respiratory apparatus 116 higher than the ambient, while the suboptimal imposed user respiratory effort is achieved.

In one preferred embodiment, particularly, the automatic respirator control system generates a current command. The electronic motor driving system delivers the commanded current through the motor. One advantage of the presented invention is that the current driver has faster response than a velocity based motor controller. The faster response enables the automatic portable purifying system 110 to better synchronize with user respiratory needs.

Still referring to the air delivery control system 224, it has the function the automatic compensate the leak from the respiratory apparatus 116. The leak can be introduced by improper respiratory apparatus 116, the loose connection in the system, or user physical activities introduced gap between the airway and respiratory apparatus 116. It is able to estimate flow leaked from the respiratory apparatus 116 and compensate for the leak flow with adjusted blower control parameter. The leak estimate utilized sensor measurements in the system. The sensor measurements include one, multiple or none of the following sensors, current measurement from the blower, and velocity measurement from the blower, blower flow measurement, blower differential pressure and pressure at the user respiratory apparatus 116. In one preferred embodiment, the respiratory apparatus 116 normal leaking rate predetermined by a pressure vs. flow characterization. The extra flow measured by the sensor can be used to estimate and predicate the degree of leaking.

Still referring to the air delivery control system 224, it has the function to alarm the user if the apparatus leak is beyond certain degree.

Still referring to the air delivery control system 224, it has the function to automatically start the air purifying process when the apparatus is detected worn properly. It also has the function to automatically suspend the air purifying process when the apparatus is detected disconnected from the user.

Air purifying system with user interface software. In a preferred embodiment, an air purifying system has software to provide user interface. The software provides useful information, such as whether the mask is wore property, the time and duration of system being used. The software can also provide warning and alarm, such as battery low and the need to replace the mask. The user interface can be on the air purifying system itself or on a device, such as cell phone.

Reliable air purifying system with self tests: In order to ensure the device function correctly. Device self tests are employed. The self tests can be classified into daily self tests, weekly tests, monthly tests, power up self tests. A preferred embodiment is to have daily tests, weekly tests, monthly tests, and power up tests. Whenever practical, critical components are tested during self tests.

Claims

An automatic wearable air purifying system which adjusts air pump working condition according to user respiratory efforts.
The imposed of respiratory effort is reduced by the automatic adjusted air pump working conditions.
An automatic wearable air purifying system which can compensate the system leak and apparatus leak automatically.
In the preferred embodiment, the pressure at the respiratory apparatus is maintained higher than the ambient pressure throughout the breath cycle.
In automatic wearable air purifying system, the reduction of imposed respiratory efforts and the reduction of power consumption can be balanced with different working scenario.
The leaking exceeds certain degree will be alarmed.
The air purifying system of claim 1 has software that provides information to the user.
The air purifying system of claim 1 has software that provides warnings and/or alarms.
The air purifying system of claim 1 has software that provides user interface on the system itself.
The air purifying system of claim 1 has software that provides user interface on a separate device.
The air purifying system of claim 1 has self tests.
The air purifying system of claim 1 has the function to automatically start the air purifying process when the apparatus is detected worn properly.
The air purifying system of claim 1 has the function to automatically suspend the air purifying process when the apparatus is detected disconnected from the user.
The driving current of air pump blower is adjusted based on the detection of user respiratory effort.
The blower velocity measurement and current measurement are employed to detect user respiratory efforts.