Surgery – Respiratory method or device – Including body or head supported means covering user's scalp
Reexamination Certificate
1998-01-06
2002-01-29
Dawson, Glenn K. (Department: 3761)
Surgery
Respiratory method or device
Including body or head supported means covering user's scalp
C128S204260, C128S204280, C128S205120, C128S205130, C128S205140
Reexamination Certificate
active
06341604
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to rebreathers and particularly to semi-closed circuit breathing apparatuses and components and accessories therefore.
2. Description of Related Art
Conventional semi-closed rebreathers operate by delivering a premixed gas from a scuba cylinder through a constant flow regulating device, usually by supplying a regulated gas supply to a changeable orifice. Gas is delivered at a preset rate regardless of depth. The gas being breathed is recirculated, and as the oxygen within the mixture is metabolically consumed, it is hopefully being adequately replaced on a continuous basis with a predetermined continuous flow of oxygen enriched gas.
Rebreathers consist of a breathing loop from which the diver inhales and into which the diver exhales. As most of the exhaled gas stays in the breathing loop, rebreathers allow for much greater gas efficiency than open circuit systems. This greater gas efficiency allows for longer duration dives as compared to open circuit systems, or, conversely, requires less gas supply for a dive of equal duration.
The breathing loop generally includes a relief valve, scrubber, counterlung, depth equalization regulator, continuous injection system, hoses and a mouthpiece. The relief valve is utilized for dumping or venting excess gas in the breathing loop created by the rebreather on ascent and excess gas which is produced with the use of constant (active) addition systems. The scrubber cleanses the exhaled gas of carbon dioxide. The counterlung or breathing bag allows for the retention of the diver's exhalation gas. The injection system adds fresh gas to the carbon dioxide cleansed gas in the breathing loop. The depth equalization regulator adds supply mix to the loop to keep pace with depth increases. The hoses are utilized to connect the counterlung and scrubber with the mouthpiece. The mouthpiece is connected to the two hoses and is the point on the breathing loop where the diver exhales and inhales. Typically, two conventional one-way valves are incorporated into the mouthpiece.
Rebreathers normally include a harness to strap the unit to the diver, with some units also including a protective case for the various above described components.
As stated above, rebreathers generally work by recycling most of a diver's exhaled breath, which travels through the breathing loop through the scrubber, and is returned to the diver during inhalation. The use of a rebreather allows a diver to remain underwater for a relatively long time as compared to the use of open circuit equipment.
Accordingly, rebreathers allow exhaled gas to be cleansed of carbon dioxide and replenished with fresh oxygen for further consumption. A traditional fixed flow (active addition) semi-closed rebreather recycles the gas the diver is breathing, removing excess carbon dioxide from the exhaled gas and replacing it with a measured amount of premixed gas to maintain an oxygen partial pressure in the inspired gas that will continue to support metabolism.
There are several previously known types of operating systems for semi-closed circuit rebreathers, including fixed discharge ratio, continuous injection and mechanically pulsed. In the 1970's, as electronically controlled rebreathers were coming into their own, a fixed discharge ratio counterlung (an inner bellows within an outer bellows) was developed for semi-closed use in Europe. This type of rebreather was coined the first “passive” addition or counter mass ratio system. “Passive” means gas is only added as required to replace gas that has been discharged from the breathing loop by the control mechanism.
Existing rebreather designs rely on stabilizing the oxygen content of the entire breathing loop, as in
FIG. 3
, thus requiring higher oxygen fractions to be added and increasing the disparity between oxygen tolerance and decompression restrictions. Prior system have placed all addition functions either upstream of the scrubber or in the counterlung.
Furthermore, all prior self-contained systems use supply bottles that are plumbed inside the rebreather. The supply bottles can be mounted inside or outside the rebreather case. Additionally, all existing hose designs utilize continuous runs of highly restrictive bur flexible hose. Some are externally weighted to reduce buoyancy. Previous systems have also utilized absorbent pads or breathing bag drains to manage water entry. No dedicated disinfecting and/or drying system has previously been incorporated into a rebreather. Gas supply bottles have previously been mounted inside or outside on the base of the rebreather itself. The present invention is directed to overcoming the drawbacks of these previous designs.
BRIEF SUMMARY OF THE INVENTION
One aspect of the present invention is a rebreather design which allows for placement of the counterlung and all gas control and loop overpressure relief functions on the exhalation side of the breathing loop upstream of the carbon dioxide scrubber. The invention also provides for placement of all gas addition functions on the inhalation side of the breathing loop downstream of the carbon dioxide scrubber. The present invention also uses a desensitized demand regulator on the inhalation side of the breathing loop to relieve water ingestion and excess carbon dioxide levels caused by a partially flooded scrubber. The interaction of the components are designed to produce significant breathing characteristic changes in the event of one or more component failures that act as an alarm system.
Some of the benefits of the present invention include, but are not limited to, the following:
(1) Greatly reduces possibility of single point gas addition failures;
(2) Automatically relieves loop breathing resistance caused by scrubber flooding;
(3) Automatically relieves loss of scrubber CO
2
absorbent efficiency caused by scrubber flooding;
(4) Every component failure produces an unignorable breathing change that serves as an alarm that doesn't have to be monitored. This eliminates the “task overload” situation that has caused many rebreather diver deaths because various types of “indicating” alarms were either ignored or not even recognized; and
(5) Prevents hypoxia through demand gas addition if systemic discharge proportions are not met by the mechanical addition system.
Accordingly, it is an object of the present invention to reduce the possibility of single point gas addition failures.
It is another object of the present invention to automatically relieve loop breathing resistance caused by scrubber flooding.
It is yet another object of the present invention to automatically relieve loss of scrubber CO
2
absorbent efficiency caused by scrubber flooding.
It is still another object of the present invention to produce an unignorable breathing change, for any component failure, to serve as an alarm that doesn't have to be monitored.
It is even still another object of the present invention to prevent hypoxia through demand gas addition if systemic discharge proportions are not met by the mechanical addition system.
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
REFERENCES:
patent: 3252458 (1966-05-01), Krasberg
patent: 3556098 (1971-01-01), Kanwisher
patent: 3595226 (1971-07-01), Newcombe
patent: 3672388 (1972-06-01), Ringwall et al.
patent: 3695261 (1972-10-01), Emmons
patent: 3794021 (1974-02-01), Lambertsen
patent: 3827432 (1974-08-01), Lindgren et al.
patent: 3951137 (1976-04-01), Conkle et al.
patent: 3957043 (1976-05-01), Shelby
patent: 3976064 (1976-08-01), Wood et al.
patent: 4423723 (1984-01-01), Winkler et al.
patent: 4440162 (1984-04-01), Sewell et al.
patent: 4454878 (1984-06-01), Morrison
patent: 4879996 (1989-11-01), Harwood, Jr. et al.
patent: 4939647 (1990-07-01), Clough et al.
patent: 4964404 (1990-10-01), Stone
patent: 4974585 (19
Dawson Glenn K.
Malin Haley & DiMaggio, P.A.
The Carleigh Rae Corp.
Weiss, Jr. Joseph F.
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