Patent Application
20170253311
The present invention relates to systems for ensuring underwater diver safety, particularly with respect to nitrogen absorption. The invention further relates to a regulator for an underwater breathing apparatus used by a diver.
The only resource for recreational divers to plan dive depth and dive durations are recreational dive planners. Recreational dive planners are based on the projected nitrogen absorption rate into the body and generally allow for recreational divers to safely dive without getting decompression sickness (DCS). However, the projected nitrogen absorption rates have been around for about 100 years, based on data from experiments conducted by the U.S. Navy, presumably on young, male divers in excellent physical condition. However, the published data is only a guide, as actual nitrogen absorption rates may vary from diver to diver and the nitrogen absorption rate of most recreational divers will vary from a theoretical standard diver on which the available data is based. Nitrogen absorption rates may even vary from male to female. Thus, it would be beneficial to provide a means by which safe diving parameters may be established without the inherent reliance on guesswork and historical data.
In one aspect, the invention provides a regulator for an underwater breathing apparatus including a housing defining a breathing cavity, a mouthpiece in communication with the breathing cavity, a valve operable to permit air from an air inlet of the regulator into the breathing cavity, and a sensor operable to measure a composition of air within one or both of the breathing cavity and the mouthpiece.
In another aspect, the invention provides an underwater breathing apparatus including a regulator having a housing defining a breathing cavity, a mouthpiece in communication with the breathing cavity, a valve operable to permit air from an air inlet of the regulator into the breathing cavity, and a sensor operable to measure a composition of contents within one or both of the breathing cavity and the mouthpiece. The underwater breathing apparatus may also include a controller communicatively coupled to the sensor. The controller is configured to monitor an output of the sensor to determine an amount of nitrogen absorption in a user of the underwater breathing apparatus.
In yet another aspect, the invention provides a method of operating an underwater breathing apparatus during a dive. The method includes opening a valve of a regulator to provide a breathing cavity of the regulator with air from an air inlet of the regulator, passing the air from the breathing cavity through a mouthpiece of the regulator for breathing by a diver, measuring a composition of exhaled contents passed from the mouthpiece back into the breathing cavity with a sensor, and determining, with a controller, an amount of nitrogen absorbed by the diver based on an output of the sensor.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
The air tank 14 contains compressed air which may have a composition of at least 20 percent oxygen. In some embodiments, the composition of the air in the air tank 14 may be compressed atmospheric air (e.g., about 21 percent oxygen and about 78 percent nitrogen, among other components) that has been filtered and dehumidified. In other embodiments, the composition of the air in the air tank 14 may be of air with a lower percentage of nitrogen and a higher percentage of oxygen (assuming a composition such as that of “Enriched Air Nitrox”). For example, the composition may include 22 percent oxygen up to about 40 percent oxygen, with less than 78 percent nitrogen. In general, the air held within the air tank 14 may be any composition of oxygen, nitrogen, helium, among other contents, that is breathable by humans when regulated to an appropriate pressure to allow a diver to remain and breathe underwater for an extended period of time. This may include Trimix (i.e., nitrogen, oxygen, helium blend) and Heliox (i.e., helium and oxygen blend) used for technical, non-recreational diving. Although it is recognized that Earth's atmospheric air has one specific composition, all the various combinations described above are inclusively referred to herein as “air”, as it is well known to perform underwater diving with breathable compositions other than the exact composition of Earth's atmospheric air.
Illustrated in
Illustrated in
Illustrated in
The primary and secondary stage regulators 34, 38 may also include a diaphragm 86, positioned at one end of the housing 58, operable to open and close the air inlet valve 74 in response to a pressure differential between the breathing cavity 82 and an ambient environment. As illustrated in
In operation, when the diver inhales, the pressure in the breathing cavity 82 drops. When the pressure in the breathing cavity 82 drops below that of the pressure of the ambient environment, the diaphragm 86 flexes inward, moving the air inlet valve 74 away from the air inlet 62 and allowing air to enter from the air tank 14. Air continues to flow from the air tank 14 into the breathing cavity 82 until the pressure of the breathing cavity 82 rises back to that of the ambient environment. The diaphragm 86 responds to the change of pressure in the breathing cavity 82 and returns to its original position, moving the linkage 90 and the air inlet valve 78 as well. When the diver exhales, the pressure of the breathing cavity 82 becomes greater than that of the ambient environment. In response, the air outlet valve 78 flexes outward allowing exhaled air to flow from the breathing cavity 82 to the ambient environment. As similarly stated above, the outlet valve 78 returns to its original position when the pressure of the breathing cavity 82 returns to balance with the pressure of the ambient environment.
Illustrated in
As shown in the illustrated embodiment of
The underwater breathing apparatus further includes a controller 110 and a dive computer 114. In some embodiments, the controller 110 is included in the dive computer 114. In other embodiments, the controller 110 and the dive computer 114 are separate components. The controller 110 is communicatively coupled to the first and second sensors 102, 106 and is configured to monitor outputs of the first and the second sensors 102, 106 to determine an amount of nitrogen absorption in the diver. The controller 110 is operable to determine the amount of nitrogen absorption in the diver by comparing the amount of nitrogen the diver inhales with the amount of nitrogen the diver exhales during each breathing cycle (i.e., one inhale and one exhale). For each breathing cycle, the controller 110 may determine the amount of nitrogen retained by the diver and may update a value of the amount of retained nitrogen so as to keep a running sum of the nitrogen absorption in the diver. In some embodiments, the controller 110 may incorporate a timer to determine a rate of nitrogen absorption within the diver.
The controller 110 may be configured to recognize when the diver is inhaling by monitoring the position of the air inlet valve 74, the diaphragm 86, the linkage 90, or by comparing the pressure of the breathing cavity 82 with the pressure of the ambient environment. The controller 110 may be configured to recognize when the diver is exhaling by monitoring the position of the position of the air outlet valve 78 or by comparing the pressure of the breathing cavity 82 with the pressure of the ambient environment.
In one embodiment, to determine the amount of nitrogen the diver exhaled, the controller 110 may record the output of the first sensor 102 during an exhale and may also measure the amount of time the diver exhaled by one of the methods explained above. The controller 110 may estimate the amount of nitrogen exhaled by the diver by multiplying the duration of the exhale by the recorded output of the first sensor 102 at a point in time during the exhale. The controller 110 may also more accurately estimate the amount of nitrogen exhaled by entering the duration of the exhale and the output of the first sensor 102 into a formula and then determining the output of the formula. Alternatively, the first sensor 102 may continuously output data and the controller 110 may continuously monitor the output of the first sensor 102 to determine the amount of nitrogen exhaled by the diver.
In one embodiment, to determine the amount of nitrogen the diver inhaled, the controller 110 may record the output of the second sensor 106 during an inhale and may also measure the amount of time the diver inhaled by one of the methods explained above. The controller 110 may estimate the amount of nitrogen inhaled by the diver by multiplying the duration of the inhale by the recorded output of the second sensor 106 at a point in time during the inhale. The controller 110 may also more accurately estimate the amount of nitrogen inhaled by entering the duration of the inhale and the output of the second sensor 106 into a formula and then determining the output of the formula. Alternatively, the second sensor 106 may continuously output data and the controller 110 may continuously monitor the output of the second sensor 106 to determine the amount of nitrogen inhaled by the diver.
The dive computer 114 is generally configured to monitor the running sum of the nitrogen absorption in a diver to prevent the diver from getting sick from the dive. The dive computer 114 may have a stored value of how much nitrogen a diver may absorb before getting decompression sickness, or other problems, from prolonged dives or dives at great depth. The controller 110 may be configured to update the running sum of the nitrogen absorption in the dive computer 114 so that the diver may be made aware by the controller 110 or the dive computer 114 of how much more nitrogen they may absorb or how long they may safely remain at the current depth or other various depths before they must return the surface.
The dive computer 114 may have a stored value for the amount of nitrogen absorption considered safe for each individual diver. The stored value may be dependent on the diver's physiology (e.g., weight, body mass index, height, etc.), age, gender, diving history, among other things. Alternatively, the dive computer 114 may have a preprogrammed dive schedule, irrespective of the diver, which may correspond to how long a diver may safely remain at certain depths determined by the rate of nitrogen absorption at each depth. The controller 110 or the dive computer 114 may be configured to update a dive schedule for the diver in response to the measured nitrogen absorption. The diver's dive schedule may include information such as the allowable, safe dive time at certain depths. The controller 110 or the dive computer 114 may measure an amount of nitrogen absorption and inform the diver how the diver must surface (i.e., rate of ascent and the duration required at respective depths during ascent) in order to surface safely. The amount of nitrogen absorption could be used for updating how long until the diver may dive again. The amount of nitrogen absorption may be used by the dive computer 114 to determine the amount of dive time remaining at each depth or in total.
Although described above as being used in conjunction with a stored value of safe nitrogen consumption or dive schedule, the overall nitrogen absorption by the diver, determined by the controller 110 and the dive computer 114, may be used in a number of different ways to determine how each diver may remain safe (e.g., to prevent decompression sickness) during their respective dives.
Although shown as being used with the pressure gauge 30, the air tank 14, the secondary second stage regulator 38, and the first stage regulator 18, it should be understood that the primary second stage regulator 34, the controller 110, and the dive computer 114 may be used independently of the above-described underwater breathing apparatus 10. For example, the primary second stage regulator 34 may be used with the controller 110 and the dive computer 114 for surface supplied diving, wherein there is a large supply of air at the surface of the water for the diver to use. In this case, it may be beneficial for the diver to more closely monitor the amount of nitrogen absorption as the amount of air available to the diver is less significant for diving times. In other embodiments, the first sensor 102, the second sensor 106, the controller 110, and the dive computer 114 may be used as described above with other diving components in other diving methods, such as with a rebreather.
Thus, the disclosure provides, among other things, a regulator for an underwater breathing apparatus for determining an amount of nitrogen absorption by a diver. Various features and advantages of the disclosure are set forth in the following claims.
