The breathing of cold air is uncomfortable and even dangerous for some, depending upon the severity of the temperature, and a person's physical health. In some situations one's survival can depend on the ability to retain body heat. There is also a danger of damage to the lung tissue in some instances. There are also specific cases in which excessive breathing of cold air can trigger heart attack, or asthma. Aside from the discomfort, inhalation of cold air can make one more vulnerable to Infection. Scarves and more sophisticated headgear have been used to lessen the effect of the cold air by retaining a bit of the heat of exhaled air, to transfer it to the incoming air, but most of these allow the incoming air to retrace the same path as the air that was just exhaled. Therefore, any residual exhaled air that is trapped in the matrix of a scarf or simple breath warmer will have to be inhaled before any fresh, oxygen-rich air is consumed.
Until recently, sensors for analyzing exhaled gasses have been available primarily in the clinical setting, since the equipment has been large, complicated, expensive, and fragile. Recently, various robust sensors have become available that can be embedded into portable equipment. This is useful for professionals such as paramedics, but there has been little reason for individuals to carry such equipment for self-analysis unless they have a particularly dangerous condition that warrants such care.
This device can take several forms, including a face mask that covers the mouth and nose, or a remote housing that is connected via hoses or other conduits to mouth or face interfaces. It's primary purpose is to warm the inhaled air, but with the addition of electronics, a secondary use, in some configurations, will be to do gas analysis on exhaled air to monitor various bodily states and diagnose and predict various diseases. A sniffer circuit, auxiliary heater, vibrational de-icer, and humidifier can be added depending upon the severity of the climate and the user's activity level. Aside from the comfort of warmed incoming air, there are actual dangers posed by cold air inhalation during exertion. Asthma and arterial thrombosis are two of the particular problems aggravated by breathing cold air, often during physical exertion such as snow shoveling.
Sensors for exhaled gasses can provide data for diagnosis of various other maladies. Accurate detection of specific VOCs (volatile organic compounds) in exhaled breath, known as biomarkers, can provide essential information for the diagnosis of specific diseases. This sensor data can be communicated to a Smartphone or other device over a WiFi or Bluetooth connection, for analysis and relay of results and warnings.
A face-worn, or otherwise accessible breathing device provides a portable means of warming inhaled air, using the waste heat of the user's exhaled breath, while also providing a platform for the mounting and interrogation of inhaled and exhaled breath sensors that can diagnose and quantify various diseases and dangers. Sensors can be included to gather data regarding ambient conditions, allowing for calculation of whether heat or vibration needs to be deployed for de-icing or comfort.
A more wearable embodiment is shown in
In some instances, temperature gradients permitting, humidity can be recirculated from exhaled gasses, by collecting moisture on a liquid permeable portion of the membrane, to be delivered on the other side of the membrane to the incoming air. For extended use in cold weather, exhaled humidity can be condensed onto non-freezing fins that drain that moisture into a humidification container to be used to humidify the incoming air.
Exhaled gasses exit away from the intake, to avoid freezing the outbound humidity onto the material that is being cooled by the incoming ambient air. Some longitudinal conduction can keep the heat exchanger warm enough to avoid freezing at the output as long as the incoming air is warmed a bit first. This can be further ensured by coating a portion of the outgoing air side of the exchanger with a non-stick material that conducts heat poorly, such as polyethylene or PTFE (TEFLON, CHEMOURS, Wilmington, Del.), so that edges that are proximate to cold air may be slightly insulated and hydrophobic, and more easily de-iced if humidity builds up on the outer edges of the exhaled breath path.
Regardless of whether the conductive membrane is made of a fan folded sheet or discreet sheets that are stacked, copper and aluminum are the primary candidates for the conductive membrane. For any given configuration, their value as a heat exchanger is optimized for weight, cost, effectiveness, durability, and ease of cleaning.
Foamed NEOPRENE (CHEMOURS, Wilmington, Del.) covers, of the variety that is found in wetsuits, may be used to insulate the assembly if desired. A forward portion of the housing may be made from a thin diaphragm 27 that allows speech to be heard through it, when not covered by an insulating flap.
In these embodiments, parts other than the heat conductive membrane may be fabricated from one or more thermoplastic polymers, such as Polycarbonate, Acrylonitrile butadiene styrene (ABS), or Polyethylene, in order to keep undesirable conduction to a minimum, thereby conserving the heat for warming the incoming air.
In these embodiments, the effectiveness of the warming properties at any given ambient temperature and activity level is a function of the length of the air path and number of layers of membrane. For much colder climates, a longer air path with more layers is desirable. This allows for a longer dwell time for exhaled gasses within the interstitial spaces to transfer their heat to the membrane, and therefore the incoming air, before being discarded.
In embodiments, an exterior flexible membrane allows voice vibrations to be transmitted out of the face mask, such that the wearer can verbally communicate with others.
Filters may be installed in various stages of the device to ensure proper inhaled air quality.
This application claims benefit of U.S. provisional patent application Ser. No. 62/775,325, the contents are set forth herein in their entirety.
Number | Date | Country | |
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62775325 | Dec 2018 | US |