# US 11,433,212 B1 · Self-contained face mask system with automatic droplet dispenser for humidification

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- Number: US 11,433,212 B1
- Document ID: US11433212B1
- Status: Granted
- Kind: B1
- Application number: 17/496,663
- Filed: 2021-10-07
- Granted: 2022-09-06
- Earliest claimed: 2021-10-07
- Assignees: Health Micro Devices Corporation
- Applicants: Health Micro Devices Corporation
- Inventors: Dean Hafeman; Seongsik Chang
- Web page: https://patentgrep.com/patent/US11433212B1

## CPC

- A61M 16/1075: {by influencing the temperature (A61M16/1045 takes precedence)}
- A61M 11/005: {using ultrasonics (spraying or atomising liquids using ultrasonic vibrations in general B05B17/06)}
- A61M 11/042: {electrical}
- A61M 15/0003: {with means for dispensing more than one drug}
- A61M 15/0085: {using ultrasonics (spraying or atomising liquids using ultrasonic vibrations in general B05B17/06)}
- A61M 15/025: {Bubble jet droplet ejection devices}
- A61M 16/0006: {with means for creating vibrations in patients' airways}
- A61M 16/0093: {by adsorption, absorption or filtration}
- A61M 16/06: Respiratory or anaesthetic masks
- A61M 16/0683: {Holding devices therefor}
- A61M 16/1065: {in the expiratory path}
- A61M 16/16: Devices to humidify the respiration air {(A61M16/1045 takes precedence)}
- A61M 16/205: {used for exhalation control}
- A61M 16/208: {Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves}
- A62B 9/003: {Means for influencing the temperature or humidity of the breathing gas}
- A62B 18/025: {Halfmasks (A62B23/02 takes precedence; surgical face masks A41D13/11)}
- A62B 18/08: Component parts for gas-masks or gas-helmets, e.g. windows, straps, speech transmitters, signal-devices (eye-pieces for protective goggles A61F9/02; composition of materials for the windows or other transparent parts A62D7/00)
- B05B 1/083: {the pulsating mechanism comprising movable parts}
- B05B 12/04: for sequential operation or multiple outlets
- B05B 17/0646: {Vibrating plates, i.e. plates being directly subjected to the vibrations, e.g. having a piezoelectric transducer attached thereto}
- A41D 13/11: Protective face masks, e.g. for surgical use, or for use in foul atmospheres (eye-masks A61F9/04 {; hoods affording protection against heat or harmful chemical agents A62B17/04})
- A61K 9/0078: {for inhalation via a nebulizer such as a jet nebulizer, ultrasonic nebulizer, e.g. in the form of aqueous drug solutions or dispersions}
- A61M 2016/0018: {electrical}
- A61M 2016/0021: {with a proportional output signal, e.g. from a thermistor}
- A61M 2016/0024: {with an on-off output signal, e.g. from a switch}
- A61M 2016/0027: {pressure meter}
- A61M 2202/0468: non-physiological
- A61M 2205/0294: Piezoelectric materials
- A61M 2205/121: interface between cassette and base
- A61M 2205/123: with incorporated reservoirs
- A61M 2205/3306: Optical measuring means
- A61M 2205/332: Force measuring means
- A61M 2205/3327: Measuring
- A61M 2205/3331: Pressure; Flow
- A61M 2205/3358: Measuring barometric pressure, e.g. for compensation
- A61M 2205/3368: Temperature
- A61M 2205/3372: Temperature compensation
- A61M 2205/3375: Acoustical, e.g. ultrasonic, measuring means
- A61M 2205/3553: remote, e.g. between patient's home and doctor's office
- A61M 2205/3561: local, e.g. within room or hospital
- A61M 2205/3592: using telemetric means, e.g. radio or optical transmission
- A61M 2205/3653: by Joule effect, i.e. electric resistance
- A61M 2205/502: User interfaces, e.g. screens or keyboards
- A61M 2205/505: Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
- A61M 2205/8206: battery-operated
- A61M 2205/8237: Charging means
- A61M 2209/045: for filling, e.g. for filling reservoirs
- A61M 2209/06: Packaging for specific medical equipment
- A61M 2230/42: Rate
- A61M 2230/432: partial CO2 pressure (P-CO2)
- A61M 2230/65: Impedance, e.g. conductivity, capacity
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- A62B: DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING (valves specially adapted for medical use A61M39/00; life-saving devices, apparatus or methods specially adapted for use in water B63C9/00; divers' equipment B63C11/00; specially adopted for use with aircraft, e.g. parachutes, ejector seats, {B64D17/00, B64D25/10}; rescue devices peculiar to mining E21F11/00)
- B05B: SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES (spray-mixers with nozzles B01F25/72; processes for applying liquids or other fluent materials to surfaces by spraying B05D)
- A41D: OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)

## Abstract

Introduced here is a face mask system having a mask enclosure that contains, or otherwise directly supports, an automated liquid-droplet dispensing mechanism (ADM) for humidification. In operation, the enclosure and ADM are compact and lightweight so that when worn by a user can be supported entirely by the user's head and neck. The enclosure can be comprised of one or more layers of breathable fabric adapted to flexibly conform to the face of a user when worn and form a cavity that is adjacent to the user's nostrils and mouth. The ADM can be comprised of a reservoir in which liquid is stored, a respiratory cycle detector, a timer and controller, and a droplet dispenser that controllably dispenses droplets of the liquid from the reservoir into the cavity for inhalation by the user.

## Claims

### Claim 1

A self-contained system comprising:
a mask enclosure comprised of breathable fabric that, when worn by a user, is adapted to flexibly conform to the face of the user to form a cavity between the mask enclosure and the face that includes the mouth and nose of the user,
wherein the mask enclosure comprises outer and inner layers of the breathable fabric, and
wherein when the mask enclosure is worn by the user, the inner layer defines a periphery of the cavity and the outer layer is exposed to ambient air outside the cavity;
a reservoir in which liquid is stored,
wherein the reservoir is located in an interstitial region between the outer and inner layers of the mask enclosure and attached to, and supported by, the mask enclosure; and
a dispensing mechanism that includes—
a sensor configured to generate measurements that are representative of a characteristic of air that is exhaled through the nostrils or mouth of the user,
a controller configured to generate a signal in response to determining, in real time based on analysis of the measurements, that an exhalation phase has ended, and
a droplet generator configured to
initiate, in response to receiving the signal from the controller, dispensation of the liquid from the reservoir into the cavity in the form of droplets that do not exceed one nanoliter in volume,
wherein dispensation begins when an inhalation phase commences, so as to humidify air drawn into the nostrils or mouth during the inhalation phase, and
wherein dispensation ends before the inhalation phase concludes, such that dispensation occurs over only an initial portion of the inhalation phase,
wherein the droplet generator is attached directly to the reservoir without any intervening tubing or channels so that the droplet generator and the reservoir are supported by the mask enclosure.

### Claim 2 (depends on 1)

The self-contained system of claim 1, wherein the droplet generator includes
(i) a plate with
a first side that has one or more ingress holes through which the liquid is able to enter the plate, and
a second side that has one or more egress holes through which the liquid is able to exit the plate,
wherein the one or more ingress holes on the first side are fluidly connected to the one or more egress holes on the second side, and
(ii) a vibration element configured to induce movement of the liquid through the plate through ultrasonic vibration.

### Claim 3 (depends on 1)

The self-contained system of claim 1,
wherein the sensor is an accelerometer that is connected to a flap situated in an exhaust valve in the breathable fabric of the mask enclosure, and
wherein the accelerometer measures motion of the flap, the motion being indicative of whether air is presently being exhaled through the nostrils or mouth of the user.

### Claim 4 (depends on 1)

The self-contained system of claim 1,
wherein the sensor is an accelerometer that is mounted to a flexible membrane embedded in the mask enclosure, and
wherein the accelerometer is configured to generate measurements that are indicative of motion of the flexible membrane.

### Claim 5 (depends on 1)

The self-contained system of claim 1,
wherein the sensor is a temperature sensor that is located along an interior surface of the mask enclosure, and
wherein the temperature sensor measures temperature of air inside the cavity of the mask enclosure, the temperature being indicative of whether air is presently being exhaled through the nostrils or mouth of the user.

### Claim 6 (depends on 5)

The self-contained system of claim 5, further comprising:
a second temperature sensor that is located along an exterior surface of the mask enclosure,
wherein the second temperature sensor measures temperature of ambient air outside the cavity of the mask enclosure.

### Claim 7 (depends on 6)

The self-contained system of claim 6,
wherein ambient temperature measurements generated by the second temperature sensor are provided to the controller as input, and
wherein the controller is further configured to establish a present phase of a breathing cycle based on a comparison of cavity temperature measurements generated by the temperature sensor and ambient temperature measurements generated by the second temperature sensor.

### Claim 8 (depends on 1)

The self-contained system of claim 1,
wherein the droplet generator includes an array of piezoelectric actuators, and
wherein each piezoelectric actuator includes (i) a chamber in which liquid is contained, (ii) a nozzle, and (iii) a piezoelectric element that is configured to displace the liquid in the chamber when a suitable voltage is applied thereto, thereby causing the liquid to be dispensed through the nozzle in the form of a droplet.

### Claim 9 (depends on 1)

The self-contained system of claim 1,
wherein the droplet generator includes an array of thermal actuators, and
wherein each thermal actuator includes (i) a chamber in which liquid is contained, (ii) a nozzle, and (iii) a heating element that is configured to heat the liquid to boiling, thereby causing a bubble to form that forces the liquid to be dispensed through the nozzle in the form of a droplet.

### Claim 10 (depends on 9)

The self-contained system of claim 9, wherein the thermal actuators in the array are operated sequentially so that droplets are dispensed at a predetermined interval.

### Claim 11 (depends on 10)

The self-contained system of claim 10, wherein the predetermined interval is less than 5 microseconds.

### Claim 12 (depends on 1)

The self-contained system of claim 1, wherein the mask enclosure includes multiple layers of the breathable fabric so that the droplets substantially are all retained inside the cavity prior to inhalation.

### Claim 13 (depends on 1)

The self-contained system of claim 1, further comprising:
a rechargeable power source to which the dispensing mechanism is electrically connected.

### Claim 14

A self-contained system comprising:
a mask enclosure that, when worn by a user, is adapted to flexibly conform to the face of the user to form a cavity between the mask enclosure and the face of the user,
wherein the mask enclosure comprises one or more layers of breathable fabric;
a reservoir assembly in which a liquid is stored,
wherein the reservoir assembly is attached to, and supported by, the mask enclosure;
a sensor configured to generate measurements that are representative of a characteristic of air that is exhaled through the nostrils or mouth of the user;
a controller configured to
monitor a breathing cycle of the user by examining, in real time, the measurements generated by the sensor, and
generate a signal in response to a determination that an exhalation phase of the breathing cycle has ended; and
a droplet generator that is configured to
initiate, in response to receiving the signal from the controller, a programmed sequence for dispensing the liquid from the reservoir, in the form of droplets that are less than 1 nanoliter in volume, into the cavity,
wherein the programmed sequence causes dispensation to occur over an interval of time that corresponds to an initial portion of an inhalation phase, and
wherein the droplet generator is attached directly to the reservoir assembly without any intervening tubing or channels so that the droplet generator and the reservoir are supported by the mask enclosure.

### Claim 15 (depends on 14)

The self-contained system of claim 14 wherein the reservoir assembly additionally comprises a concentrated reagent that is separated from the liquid that acts as a diluent.

### Claim 16 (depends on 15)

The self-contained system of claim 15, wherein the concentrated reagent comprises equimolar amounts of elemental iodine and iodide anion.

### Claim 17 (depends on 16)

The self-contained system of claim 16, wherein upon mixing the concentrated reagent and the liquid, the resulting mixture is a solution comprising between 5 nanomolar and 5 micromolar concentrations of elemental iodine, iodide anion, or tri-iodide anion (I3−).

### Claim 18 (depends on 14)

The self-contained system of claim 14, wherein a volume of liquid stored by the reservoir assembly is no greater than 100 milliliters.

### Claim 19 (depends on 14)

The self-contained system of claim 14,
wherein the sensor is an accelerometer that is mounted to a flexible membrane embedded in the mask enclosure,
wherein the flexible membrane is in contact with the cavity, and
wherein the accelerometer monitors motion of the flexible membrane that is caused by reversals in direction of airflow through the nostrils of the user.

### Claim 20

The self-contained system of 14, wherein the droplet generator includes
(i) a plate with
a first side that has one or more ingress holes through which the mixture is able to enter the plate and
a second side that has one or more egress holes through which the mixture is able to exit the plate,
wherein each ingress hole on the first side is fluidly connected to a corresponding egress hole on the second side, and
(ii) a vibration element configured to induce movement of the mixture through the plate by ultrasonic vibration.

### Claim 21 (depends on 14)

The self-contained system of claim 14, wherein a weight of the self-contained system is less than 100 grams.

### Claim 22 (depends on 14)

The self-contained system of claim 14, wherein the droplets are dispensed over the interval of time at a frequency of at least 100 kilohertz.

### Claim 23

A self-contained system comprising:
a mask enclosure comprised of outer and inner fabric layers that, when worn by a user, is adapted to flexibly conform to the face of the user to form a cavity that includes the mouth and nose of the user,
wherein when the mask enclosure is worn by the user, the inner fabric laver defines a periphery of the cavity and the outer fabric laver is exposed to ambient air outside the cavity;
a dispensing mechanism that includes:
(i) a reservoir in which liquid is stored, the reservoir being located in an interstitial region between the outer and inner fabric layers of the mask enclosure,
(ii) a droplet generator that is in direct fluid communication with the reservoir without any intervening tubing or channels,
(iii) a respiratory cycle detector that includes a sensor able to monitor a breathing cycle of the user, and
(iv) a controller that is in electronic communication with the respiratory cycle detector and the droplet generator, and
wherein the dispensing mechanism provides for dispensation of droplets that are less than 1 nanoliter in volume into the cavity in response to measurements made by the sensor of the respiratory cycle detector,
wherein the measurements are representative of a characteristic of air that is exhaled through the mouth or nose of the user, and
wherein dispensation of the droplets begins when an inhalation phase of the breathing cycle of the user commences, so as to humidify air drawn into the mouth or nose during the inhalation phase.

### Claim 24 (depends on 23)

The self-contained system of claim 23, wherein the droplet generator includes
(i) a plate with
a first side that has one or more ingress holes through which the liquid is able to enter the plate, and
a second side that has one or more egress holes through which the liquid is able to exit the plate,
wherein the one or more ingress holes on the first side are fluidly connected to the one or more egress holes on the second side, and
(ii) a vibration element configured to induce movement of the liquid through the plate through ultrasonic vibration.

### Claim 25 (depends on 23)

The self-contained system of claim 23,
wherein the sensor is an accelerometer that is connected to a flap situated in an exhaust valve in the one or more breathable fabric layers of the mask enclosure, and
wherein the accelerometer measures motion of the flap, the motion being indicative of whether air is presently being exhaled through the mouth or nose of the user.

### Claim 26 (depends on 23)

The self-contained system of claim 23,
wherein the sensor is an accelerometer that is mounted to a flexible membrane embedded in the mask enclosure, and
wherein the accelerometer is configured to generate measurements that are indicative of motion of the flexible membrane.