BE1024595B1 - SUBAQUATIC BREATHING ASSEMBLY - Google Patents

Abstract

The present invention provides an innovative underwater breathing equipment for extracting from the underwater environment a breathable gas, thus providing a solution to the problems of autonomy, congestion and energy consumption of existing techniques. The equipment is an underwater breathing assembly comprising a circulation ring of an oxygen carrier fluid passing through a gill cage and a pulmonary chamber with a breathing mouth.

Description

(30) Priority data:

(73) Holder (s):

APA PRODUCTIONS SPRL 1170, BRUXELLES Belgique (72) Inventor (s):

CLAEYSSEN Pierre 1050 BRUXELLES Belgium (54) UNDERWATER BREATHING ASSEMBLY (57) The present invention provides innovative underwater breathing equipment enabling a breathable gas to be extracted from the underwater environment, thus providing a solution to the problems of autonomy, size and energy consumption of existing techniques. The equipment is an underwater breathing kit comprising a circulation ring of an oxygen-carrying liquid passing through a gill cage and a lung chamber with a breathing mouth.

BELGIAN INVENTION PATENT

FPS Economy, SMEs, Middle Classes & Energy

Publication number: 1024595 Deposit number: BE2017 / 5490

Intellectual Property Office International Classification: B63C 11/18 Date of issue: 04/17/2018

The Minister of the Economy,

Having regard to the Paris Convention of March 20, 1883 for the Protection of Industrial Property;

Considering the law of March 28, 1984 on patents for invention, article 22, for patent applications introduced before September 22, 2014;

Given Title 1 “Patents for invention” of Book XI of the Code of Economic Law, article XI.24, for patent applications introduced from September 22, 2014;

Having regard to the Royal Decree of 2 December 1986 relating to the request, the issue and the maintenance in force of invention patents, article 28;

Given the patent application received by the Intellectual Property Office on 07/10/2017.

Whereas for patent applications falling within the scope of Title 1, Book XI of the Code of Economic Law (hereinafter CDE), in accordance with article XI. 19, §4, paragraph 2, of the CDE, if the patent application has been the subject of a search report mentioning a lack of unity of invention within the meaning of the §ler of article XI.19 cited above and in the event that the applicant does not limit or file a divisional application in accordance with the results of the search report, the granted patent will be limited to the claims for which the search report has been drawn up.

Stopped :

First article. - It is issued to

APA PRODUCTIONS SPRL, Chaussée de la Hulpe 150, 1170 BRUXELLES Belgium;

represented by

OFFICE KIRKPATRICK S.A., Avenue Wolfers 32, 1310, LA HULPE;

a Belgian invention patent with a duration of 20 years, subject to payment of the annual fees referred to in article XI.48, §1 of the Code of Economic Law, for: SUBAQUATIC BREATHING ASSEMBLY.

INVENTOR (S):

CLAEYSSEN Pierre, Rue des Egyptiens 13, 1050, BRUXELLES;

PRIORITY (S):

DIVISION:

divided from the basic application: filing date of the basic application:

Article 2. - This patent is granted without prior examination of the patentability of the invention, without guarantee of the merit of the invention or of the accuracy of the description thereof and at the risk and peril of the applicant (s) ( s).

Brussels, 04/17/2018, By special delegation:

BE2017 / 5490

Underwater breathing kit

The invention relates to the field of respiratory equipment for underwater diving, in fresh or salt water in non-stagnant environments, for example at sea, in a river or in a lake.

Underwater diving, that is to say, recreational scuba diving, diving of rescue or research teams, in lake or river, or diving of technical intervention personnel on equipment underwater, is currently done using a scuba comprising one or more bottles of compressed air, connected to a regulator allowing the diver to breathe air at ambient pressure.

The main limitation to the use of scuba gear is their autonomy. The quantity of air contained in the bottles allows a diver to remain submerged for only a few hours. Depending on the depth of the dive, time must be allowed for the decompression stops, which further limits the "effective" dive time.

The need for decompression stops is mainly explained by the behavior of the dinitrogen breathed in human biological tissue. Indeed, the air breathed on the surface of the earth, and therefore also contained in the compressed air bottles, contains around 80% of dinitrogen. This dinitrogen penetrates and remains longer in biological tissue than oxygen, since it is neither metabolized nor "transported", that is to say adsorbed by proteins such as hemoglobin. When the diver ascends, the pressure to which his body is subjected gradually decreases, and the dinitrogen contained in the cells, organs or arteries may then form

BE2017 / 5490 bubbles that can lead to damage to certain organs and can be potentially fatal.

To reduce the risks associated with decompression, the compressed air in the bottles can be more concentrated in oxygen or contain added gases, such as rare gases, to form tri-gas mixtures such as, for example, heliox or trimix. These mixes make it possible to reduce the duration of decompression stops or to lengthen the depth interval between two stops, and allow greater depths to be reached. They do not, however, extend the total duration of a dive.

Solutions for allowing humans to remain underwater for long periods have been developed, for example in submarines. The electrolysis of water generates oxygen to allow the residents of the submarine to breathe. However, this technique requires a lot of energy, which generally comes from batteries, heat engines or fuel cells, energy which must in one way or another be regenerated by rising to the surface.

An autonomous underwater breathing apparatus for a diver is described in patent application WO 02/40343. In this device, water from the underwater environment is pumped to an air / water separator. The air is separated from the water by cavitation, volumetric increase or centrifugal force, then sent to a storage pocket. The air extraction rate may be higher than the need of the plunger. A detector placed at the level of the storage pocket controls the separator pump, switching off the pump when a threshold pressure is reached. To provide sufficient air flow to the plunger, the pump must stir

BE2017 / 5490 two thousand liters of seawater per minute, which requires considerable energy. The separator must also have a diameter of about twenty-five centimeters and a length of about fifty centimeters, not counting the volume of air storage, which makes the equipment at least as bulky as an autonomous diving suit. The use of an electronic sensor also reduces the reliability and longevity of such equipment, which presents a non-negligible risk for a diver.

It was therefore considered necessary by the applicant to provide a solution to the problems of autonomy, size and energy consumption of existing techniques.

It is the object of the present invention to provide innovative underwater breathing equipment making it possible to extract a breathable gas from the underwater environment.

Solution of the invention

The present invention provides for this purpose an underwater breathing assembly comprising a ring for circulation of an oxygen-carrying liquid, a gill cage and a lung chamber with a breathing mouth, said ring passing through the gill cage and the lung chamber.

The inventive activity involved in this invention lies in the audacity to have wanted to combine, mechanically, chemically and electronically, simulators of living organs of humans and fish.

BE2017 / 5490

Advantageously, the circulation ring is permeable to oxygen and the pulmonary chamber is arranged to cause the pervaporisation of oxygen, transported by the permeable transport liquid.

oxygen, through

The ring

Advantageously also, the gill cage is arranged to allow the diffusion of oxygen, from the underwater medium to the oxygen-carrying liquid, through the permeable ring.

To allow the vaporization of a breathable gas, that is to say containing proportions of dinitrogen and oxygen that a human being can breathe without risk of hypoxia or hyperoxia, at the level of the pulmonary caisson, it is interesting that the circulation ring is also permeable to dinitrogen. Thus, nitrogen and oxygen can on the one hand diffuse from the aquatic medium to the oxygen-carrying liquid, and on the other hand be pervaporized at the level of the pulmonary chamber.

By oxygen-carrying liquid is meant a liquid, preferably an aqueous solution, in which the oxygen is not simply dissolved, but actively adsorbed by a substance having a strong interaction with oxygen, i.e. - say by a mechanism called "cooperative". An oxygen-carrying liquid can for example be blood or an aqueous solution comprising hemoglobin or any other protein capable of fixing or adsorbing several oxygen molecules. Hemoglobin in the blood in fact transports 70 times more oxygen than the amount of oxygen simply dissolved in the blood. Others

BE2017 / 5490 substances, protein or not, of natural or synthetic origin, are for example myoglobin, hemocyanin,

Erythrocruorin or perfluorodichlorooctane. More generally, the carrier liquid therefore comprises at least one component capable of adsorbing oxygen.

The oxygen-carrying liquid, like blood, can also dissolve other gases such as dinitrogen or carbon dioxide, and passively transport them in dissolved form.

The terms oxygen and dioxygen denote here indifferently the molecule made up of two oxygen atoms and of chemical formula O2. Likewise, the terms nitrogen and nitrogen denote indifferently here the molecule made up of two nitrogen atoms and of chemical formula N ₂ .

The circulation ring here generally designates a closed circuit, without any particular essential limitation of shape or material. The circuit can be divided, over certain portions of its length, into several parallel channels or sub-circuits which then meet.

The gill cage is a part of the whole reproducing at least in part the functionality of a fish gill. A gill is an organ intended to be in direct contact with a stream of water from the underwater environment in which the fish is immersed and having, in a limited volume, a large vascularized surface. The blood of the vessels captures gases dissolved therein in the water and releases carbon dioxide dissolved therein into the blood, by osmotic diffusion through the

BE2017 / 5490 permeable membrane formed by the vascular walls. Osmotic diffusion refers to the phenomenon of transfer of elements between two solutions separated by a semi-permeable membrane, the elements diffusing from the most concentrated solution to the least concentrated solution until an equilibrium is reached.

The terms pe indifferently allows gases to pass through as rmable and semi-permeable are used here to denote the fact that the membrane only has certain elements, in this case here oxygen or nitrogen.

A lung chamber here designates a sealed compartment which can have any shape, does not contain liquid water and at least partially mimics the functions of a lung. The pulmonary chamber designated here is similar in particular to a pulmonary cavity during its expiration phase. In humans, a lung is characterized by a large alveolar surface with a very thin wall traversed by blood capillaries. The alveolar wall and the walls of the capillaries act as a permeable membrane allowing gas exchanges between the blood and the ambient air. During inspiration, the ambient air pressure increases in the pulmonary cavity, promoting the diffusion of gases through the permeable membrane and their dissolution in the blood. During expiration, the ambient air pressure decreases and promotes the opposite phenomenon, that is to say the desorption of gases through the permeable membrane towards the pulmonary cavity. The gases passing here from a liquid, or dissolved, phase to a gaseous phase, we speak of pervaporisation phenomenon.

BE2017 / 5490

The breathing mouth is here to be taken in the broad sense of an opening. The lung chamber is arranged so that a human can suck out the gaseous contents. It can for example be connected to a pipe having a nozzle that a diver can place in his mouth, like a regulator used in scuba gear. It can also be arranged so as to supply breathing air to a space where several people can reside without carrying on them any particular equipment, such as for example the cabin of a submarine or a research station or an underwater capsule.

Advantageously, the circulation of the oxygen-carrying liquid is ensured by a pump.

The invention will be better understood using the following description of several embodiments of the assembly

of the invention, in reference to the drawing in annex, on which : Figure 1 is a 1 'block diagram together the invention; figure 2 is a schematic view from above from the cage

branchial of the whole of the invention;

Figure 3 is a schematic side view of the gill cage of the assembly of the invention and Figure 4 is a schematic side view of the lung chamber of the invention.

Referring to Figure 1, the underwater breathing assembly 1 comprises a ring 2 for circulation of a

BE2017 / 5490 oxygen-carrying liquid 3. The ring 2 passes through a gill cage 4 and a lung chamber 5 having a breathing mouth 6. The ring 2 also passes through a pump 7.

The pump 7 ensures the circulation of the oxygen-carrying liquid 3 in the ring 2. The pump 7 can be any type of continuous pump, capable of operating under water or being sufficiently protected to operate under water at a wide range of pressures. To ensure the breathing of a diver, a small pump is sufficient, which can be powered by a low power battery, such as for example a cardiac simulator.

With reference to FIG. 2, at the level of the inlet 8 of the cage, the ring 2 is divided into two sub-circuits 2a and 2b outside the gill cage 4, and come together at the same level after having each traversed a lobe of the gill cage 4. The circuits 2a and 2b divide and gather here outside the gill cage. It is nevertheless conceivable that the division and / or the gathering will take place inside the cage.

In practice, the oxygen-carrying liquid 3 circulating in the ring 2, then in the sub-circuits 2a and 2b, enters the branchial cage 4. This cage being an open space on the aquatic environment, the circuits 2a and 2b are directly in contact with the aquatic environment. The sub-circuits 2a and 2b being made up of a permeable or semi-permeable membrane, diffusion of the gases dissolved in the aquatic medium towards the oxygen-carrying liquid 3 takes place through the permeable membrane, if the

BE2017 / 5490 oxygen-carrying liquid has a lower gas concentration than the aquatic environment.

The gases in question are mainly dinitrogen and oxygen. There may also be traces of other gases.

The oxygen-carrying liquid comprises at least one component capable of adsorbing oxygen, for example hemoglobin. The oxygen which has diffused and which has dissolved in the liquid 3 is adsorbed on the hemoglobin. The concentration of oxygen simply dissolved in the liquid thus remains low and the equilibrium of diffusion of oxygen through the membrane is less quickly reached. The presence of hemoglobin in the liquid 3 thus allows the circuit to transport a greater quantity of oxygen than it would have been possible thanks to the simple phenomenon of dissolution of the gases, the oxygen being here transported both in the form dissolved and in adsorbed hemoglobin form. This also makes it possible to transport an oxygen / dinitrogen ratio a priori higher than the ratio present in the underwater environment, this ratio thus being similar to that transported by the blood.

At the outlet of the gill cage 4, the sub-circuits 2a and 2b meet.

Thus, at the outlet of the gill cage 4, the oxygen-carrying liquid 3 circulating in the ring 2 is loaded with dissolved and / or adsorbed gases.

The circuits 2a and 2b are shown here arranged in serpentines, symmetrically. The serpentine configuration allows for a large contact surface

BE2017 / 5490 between the membrane and the aquatic environment, thus optimizing the diffusion of gases. Others

configurations are all to made possible for get the same result, like example one configuration in spiral. Ring 2, and the sub-circuits 2a and 2b are at least in

part constituted by a permeable or semipermeable hydrophobic membrane arranged to envelop the oxygen-carrying liquid.

The expression “permeable or semi-permeable hydrophobic membrane” denotes a thin wall, made from a natural material or a synthetic polymer, comprising pores allowing certain substances to pass selectively, depending on its chemical nature and its physical structure, but not water molecules. The pores of the membrane used here are such as to allow oxygen and nitrogen to pass. This type of membrane also makes it possible to prevent the passage of viruses or bacteria, ensuring the sterility of the transferred gases, or of particles, thus preventing the formation of mosses or algae in the circuit. It is thus not necessary to use any other filter in the circulation ring 2. Additional filters could have a negative effect on the liquid flow, especially if they become clogged gradually, with a negative impact on the performance of the equipment. Such filters would require regular maintenance.

The circuits formed by the membrane are a priori flexible and arranged so that there is no elbow formation which could have a harmful effect on the flow rate of the liquid circulating there. In order to maintain, support and / or

BE2017 / 5490 protect, the gill cage 4 preferably consists of a rigid structure, open so as to allow the circulation of water from the aquatic environment. This circulation is for example ensured by the natural current of the medium or by the displacement of the plunger equipped with the assembly of the invention.

In order to optimize the efficiency of the assembly, the exposed membrane surface of the part of the ring 2 traversing the gill cage 4 can be calculated as a function of several parameters, such as for example the nature of the membrane and / or its performance in allowing the diffusion of gases or the purpose of the equipment, that is to say if it is intended for a single diver or for an underwater capsule, a marine environment or fresh water. To reach the optimal contact surface between the membrane and the aquatic environment, the ring 2 can be divided, at the level of the gill cage 4, into a multitude of sub-circuits. In order to optimize the compactness of the equipment according to the desired surface, the sub-circuits can be "stacked".

As illustrated in FIG. 3, the gill cage 4 can comprise several stacked units 12i, here fifteen units represented horizontally, each unit 12i being for example made up of the sub-circuits 2a and 2b described above. The ring 2 is divided, over a portion of its length, here the portion traversing the gill cage, into several parallel sub-circuits, here thirty sub-circuits not shown, at the level of an anastomosis compartment 10, that is to say i.e. splitting and reconnecting the sub-circuits. The rigidity of the structure is ensured by uprights 11 making it possible to maintain a distance

BE2017 / 5490 constant between units. Two uprights of the same height as the stack are shown here, but their number can vary, just as they can have a different height and / or be arranged in any other way. It is also possible to ensure the rigidity of the system without any amount.

It is possible to insert a lattice type separator between each unit, that is to say through which the water circulates easily, which can serve as a support and / or separator for the sub-circuits.

The distance between the units is calculated so as to optimize the aquatic flow and allow each surface unit of the membrane to be sufficiently exposed to the current of the aquatic environment.

In the same way that water circulates through the gills of a fish, either thanks to the current, or thanks to the displacement of the fish, a current of the underwater medium must circulate here through the gill cage 4 to ensure the continuity of the gas supply.

After having traversed the branchial cage 4, the oxygen-carrying liquid 3 from the ring 2 is conveyed, by virtue of the flow generated by the pump 7, to the pulmonary caisson

5.

With reference to FIG. 4, the pulmonary caisson 5 comprises a second compartment 13 for anastomosis of entry into the pulmonary caisson where the ring 2 is divided, here again, into multiple parallel sub-circuits 15i, represented here in perspective. These sub-circuits, arranged here in a glomerular way, that is to say as if they

BE2017 / 5490

were passing around of a sphere, roam the box pulmonary 5 then they gather at level d 'a third compartment 15 anastomosis Release of the box pulmonary. A mouth 6 is ie a orifice, east

disposed on one of the surfaces of the pulmonary chamber 4. The mouth 6 is here connected to the end of a pipe 16, the other end of which is equipped with a regulator 17 provided with a mouthpiece 18.

In practice, when a diver, having inserted the mouthpiece 18 of the regulator 17 in his mouth, inhales, a depression is created in the chamber 5 inducing a partial pressure difference of the gases between the dry interior of the chamber and the liquid oxygen transporter 3 traversing the sub-circuits 15i. This partial pressure difference causes the gas to vaporize, that is to say the passage of gases, by diffusion through the semipermeable membrane, of their dissolved and / or adsorbed form in the liquid 3 to a gaseous form in the volume. of the housing 5.

The glomerular arrangement of the sub-circuits 15i here makes it possible to increase the exchange surface of the semipermeable membrane for a smaller volume of the pulmonary chamber and thus to favor the release of the gas molecules over a shorter route. Any other provision allowing effective pervaporisation is nevertheless possible.

The anastomosis inlet 13 compartments, for dividing the circuits, and outlet 14, for reconnecting them, also here ensure good distribution of the flow rate of the oxygen-carrying liquid 3 along the ring 2 It is of course conceivable that the inlet and outlet anastomosis compartments are

BE2017 / 5490 arranged side by side or in any other way, the subcircuits then having to be adequately curved inside the lung chamber 5.

The regulator 17 functions here as a non-return valve. Thus, the air exhaled by the plunger does not return to the lung chamber 5. This ensures that the pressure in the chamber 5 is maintained at the maximum at equilibrium pressure with the oxygen-carrying liquid 3, the pressure of equilibrium being the sum of the partial pressures of the various released gases. In this configuration, the oxygen-carrying liquid 3 cannot therefore, at the level of the pulmonary caisson 5, reabsorb gas.

It is conceivable to replace the regulator with other valve systems known to those skilled in the art.

Thus, in the same way that blood releases, at the level of the pulmonary alveoli of a human, the gases not used during expiration, a gaseous mixture dissolved in the oxygen-carrying liquid 3 is released into the pulmonary chamber 5 .

At the outlet of the lung chamber 5, the oxygen-carrying liquid 3 circulating in the ring 2 contains very little dissolved and / or adsorbed gas, according to the meaning mentioned above.

After having traversed the oxygen transporter thanks to the generated branchial flow 4.

lung chamber 5, the liquid 3 from the ring 2 is redirected, by the pump 7, to the cage

BE2017 / 5490

The three anastomosis compartments 10, 13 and 14, described here, are arranged to ensure a fluid passage of the oxygen-carrying liquid 3 along the circulation ring 2, in particular at the level of the divisions and reconnections of the sub-circuits. . These compartments prevent local overpressures which can damage the permeable membrane.

The whole of the invention can therefore continuously supply a breathable gas in the pulmonary chamber, allowing a diver to overcome the time constraints that he would have with a conventional autonomous diving suit.

As the amount of dissolved gases in aquatic environments increases with depth, the system even gains in efficiency.

The desorption of the gases is proportional to the depression created in the lung chamber 5 during the inspiration of the plunger, which is itself directly proportional to the amount of air inspired by the plunger. Thus, the system is self-regulating, and no complex system of sensors is required.

The service life of the equipment is theoretically infinite, and in practice only limited by normal wear and tear. It is advantageous, for example, to provide a closable opening in the ring 2 to allow the emptying and filling of the oxygen-carrying liquid 3. This liquid is nevertheless prepared so as to have a long shelf life. If it is prepared from blood, it will be treated so that there is no clotting

BE2017 / 5490 possible and that all of its components are stable over time.

Thanks to an “active” transport of oxygen in the oxygen-carrying liquid 3, the air released into the lung chamber is enriched with oxygen, which makes it possible to reduce the compression stages during the ascent of the plunger. It is nevertheless important to configure the whole of the invention so as not to deliver partial pressure of oxygen beyond the toxicity threshold, that is to say in order not to place a diver in a situation of hyperoxia . The configuration parameters to take into account are at least the membrane surface in contact with the aquatic medium in the gill cage, the membrane surface exposed in the pulmonary chamber, the diffusion capacity of the membrane, the flow rate of the pump, concentration of oxygen-carrying components or, more generally, the composition of the oxygen-carrying liquid. Blood and in particular hemoglobin is used here. A liquid comprising for example perfluorodichlorooctane, a non-protein compound, can also be used.

actively

The regulation of the oxygen level in the pervaporized air in the pulmonary chamber can also imply coupling the whole of the invention to a recycler, that is to say a circuit for recycling the gases exhaled by the plunger. Recyclers are well known to diving specialists. Such systems can indeed prove useful in the context of an underwater capsule whose residents cannot breathe directly out of the capsule. In the context of a single diver, the coupling of the equipment of the invention with a recycler could

BE2017 / 5490 also make it possible to further reduce the size of the assembly, recycling making it possible to reduce the need to extract gases from the aquatic environment.

The whole of the invention and the different elements can take multiple forms which are not limited to the forms described above. In the case of equipment for a diver, it is important that the ring 2 is sufficiently protected so that it does not deteriorate in contact with obstacles, such as rocks, or that it hangs not to aquatic vegetation. The lung box can take any shape, including ergonomic shapes that allow the diver to remain free to move. In the case of an underwater capsule, the assembly of the invention can be judiciously arranged on the passenger compartment so that the gill cage receives the current optimally when the capsule moves.

Claims (10)

Claims 1. An underwater assembly (1) comprising a ring (2) for circulation of an oxygen-carrying liquid (3), a gill cage (4) and a lung chamber (5), characterized in that it is respiration, the lung chamber comprising a breathing mouth (6), said ring passing through the gill cage (4) and the lung chamber (5). 2. The assembly of claim 1, wherein the circulation ring (2) is permeable to oxygen and the lung chamber (5) is arranged to cause the pervaporisation of oxygen, transported by the oxygen-carrying liquid ( 3), through the permeable ring. 3. The assembly of claim 2, wherein the gill cage (4) is arranged to allow the diffusion of oxygen from the underwater medium to the oxygen-carrying liquid (3), through the permeable ring. 4. Assembly according to one of claims 1 to 3, wherein the oxygen-carrying liquid (3) comprises at least one component capable of adsorbing oxygen. 5. Assembly according to one of claims 1 to 4, wherein there is provided a pump (7) for ensuring the circulation of the oxygen-carrying liquid (3). 6. Assembly according to one of claims 2 to 5, wherein the ring (2) of circulation is also permeable to dinitrogen. 7. Assembly according to one of claims 1 to 2, in which the oxygen and the dinitrogen are soluble in the liquid t r a n s p o r t u o o x y g · è n e (3). 8. Assembly according to one of claims 1 to 7, wherein the circulation ring (2) comprises at least one permeable or semi-permeable hydrophobic membrane arranged to envelop the oxygen-carrying liquid. 9. Assembly according to one of claims 1 to 8, in which the gill cage (4) is arranged to allow the circulation of a current of the underwater medium. 10. Assembly according to one of claims 1 to 9, in which the circulation ring (2) divides, BE2017 / 5490 over a portion of its length, in several parallel sub-circuits. BE2017 / 5490 BE2017 / 5490 U5 <υ υ && LU "st BE2017 / 5490 BE2017 / 5490 BE2017 / 5490 BE2017 / 5490 The present invention provides an innovative underwater breathing equipment making it possible to extract a breathable gas from the underwater environment, a solution to the problems of energy self-sufficiency of t, thus providing space and existing chemicals. : ο n omma t r ο n The equipment is an underwater breathing assembly comprising a ring for circulation of an oxygen-carrying liquid passing through a gill cage and a pulmonary chamber with a breathing mouth.