CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.

REFERENCE TO A MICROFICHE APPENDIX [0003] Not applicable.

FIELD OF THE INVENTION [0004] Disclosed embodiments relate generally to systems and methods for monitoring and indicating air pressure or capacity in a self-contained breathing apparatus.

BACKGROUND

[0005] Traditionally, a self-contained compressed air breathing apparatus (or SCBA) may use a high-pressure gauge, either analog or digital, where the gauge indicates the air pressure of one or more container (for example, tanks or cylinders) within the SCBA. Air pressure level may indicate to a user the remaining service life available, so that a user may plan to be in a safe environment when the container(s) are empty, for example. However, a traditional analog or digital pressure gauge may be inconvenient for a user to see or read, or may be out of the line of sight of a user, when the user is wearing the SCBA. Applicants have found that the use of a heads-up display device (or HUD) may provide constant indication of the pressure level to a user or provide a warning that is more readily apparent to eh user (e.g. always in the line of sight). For example, the HUD may be installed onto a facepiece or mask of the SCBA and may utilize lights, such as LEDs as indicators. Also, applicants have found that it may be advantageous to connect an HUD wire or wirelessly to a transducer operable to monitor the air pressure within the SCBA. Thus, Applicants have developed an improved transducer system operable to communicate pressure signals to an HUD.

SUMMARY

[0006] Aspects of the disclosure may include embodiments of a self-contained breathing apparatus comprising: one or more air cylinders; a pressure reducer; a mask having a heads- up display device; a demand valve operable to attach to the mask; a medium-pressure hose from the pressure reducer to the demand valve, wherein the pressure reducer may be in fluid communication with the demand valve; a combined pressure gauge and warning whistle; a high-pressure transducer; a lower high-pressure hose between the pressure reducer and the transducer, wherein the pressure reducer may be in fluid communication with the transducer; an upper high-pressure hose between the transducer and the combined pressure gauge and whistle, wherein the transducer may be in fluid communication with the combined pressure gauge and whistle, wherein: the upper and lower high-pressure hoses may be operable to transmit both high-pressure and medium-pressure air; and the transducer may comprise a high-pressure pathway and a medium-pressure pathway.

[0007] In some embodiments, the transducer may comprise a pneumatic switch, a high- pressure sensor in fluid communication with the high-pressure pathway, and a processor with a signal transmitter for communicating with the heads-up display device. In some embodiments, the upper and lower high-pressure hoses may each comprise an inner high- pressure tube and an outer medium-pressure tube. In some embodiments, the high-pressure tubes of the upper and lower high-pressure hoses may be in fluid communication through the high-pressure pathway in the transducer and may provide high-pressure air from the cylinder(s) to the pressure gauge. In some embodiments, the medium-pressure tubes of the upper and lower high-pressure hoses may be in fluid communication through the medium- pressure pathway in the transducer and may provide medium-pressure air from the pressure reducer to the warning whistle. In some embodiments, the medium-pressure air from the reducer may only be transmitted through the upper and lower high-pressure hoses when the high-pressure air from the cylinder(s) drops below a pre-set limit. In some embodiments, the high-pressure pathway in the transducer may comprise a main through line and a branch line, and the branch line may be in fluid communication with the pneumatic switch (e.g. the piston of the switch). In some embodiments, the pneumatic switch may be actuated by high- pressure air in the branch line, and where movement of the pneumatic switch may place the high-pressure sensor in fluid connection with the branch line so that the high-pressure sensor may detect the pressure and convert pressure to electrical signals, and wherein the electrical signals are transmitted to the processor, which may communicate with the heads-up display device. In some embodiments, the heads-up display device may indicate low pressure in the cylinder(s).

[0008] Other aspects of the disclosure include a transducer for use with a self-contained breathing apparatus (SCBA) having a heads-up display device (HUD) comprising: a body having a high-pressure pathway and a medium-pressure pathway; a pressure sensor; and a processor, wherein: the high-pressure pathway comprises a main through line and a branch line (branching off the main through line); the branch line is operable to be in fluid commination with the pressure sensor, the pressure sensors is operable to convert mechanical pressure to electrical signals, and the processor is operable to transmit a signal to the HUD. In some embodiments, the transducer further comprises a pneumatic switch having two positions, wherein in the first position the pneumatic switch blocks air flow from the branch line to the sensors, but in the second position the pneumatic switch allows fluid communication from the branch line to the sensor. In some embodiments, the branch line may be in fluid communication with the pneumatic switch, and the position of the switch (which may be governed by the pressure in the branch line) controls fluid flow to the sensor. In some embodiments, the pneumatic switch also may activate power to the processer and/or sensor. For example, when the switch is in the second position, it may complete a circuit for a battery. In some embodiments, the transducer body may also comprise two connection ports, operable to allow for removable sealing attachment of high-pressure hoses (for example, an upper and lower high-pressure hose). The ports may interact with the high- pressure pathway and medium-pressure pathway so that, when upper and lower high-pressure hoses are attached to the transducer, high-pressure air from an inner high-pressure tube in the hoses is in fluid communication with the high-pressure pathway and medium-pressure air from an outer tube in the hoses is in fluid communication with the medium-pressure pathway. In some embodiments, the transducer may further comprise an upper high-pressure hose (operable to connect to a combined pressure gauge and whistle) and a lower high-pressure hose (operable to connect to a pressure reducer or one or more air cylinders) wherein the hoses each comprise an inner high-pressure tube and an outer medium-pressure tube. And in some embodiments, the processor might communicate with the HUD via wireless transmission.

[0009] Additional aspects of the disclosure may include a method of retrofitting or upgrading an existing self-contained breathing apparatus with a pressure transducer and heads- up display device comprising: providing a pressure transducer and heads-up display device; integrating the pressure transducer into the high-pressure hose leading from the pressure reducer to a (analog) pressure gauge and whistle; and adding the heads-up display device to a self-contained breathing apparatus mask, wherein the pressure transducer detects the high- pressure air in the high-pressure hose and transmits a signal to the heads-up display device. In some embodiments, the pressure transducer may pass high-pressure air through to the pressure sensor and medium pressure air through to the whistle. In some embodiments, integrating the pressure transducer into the high-pressure hose might comprise replacing the existing high- pressure hose with an upper and lower high-pressure hose, wherein the lower high-pressure hose would connect to the pressure reducer, the pressure transducer would connect to the lower high-pressure hose, the upper high-pressure hose would connect to the transducer, and the pressure gauge/whistle would connect to the upper high-pressure hose. In some embodiments, the standard pressure reducer may not be modified or replaced, and/or the pressure reducer may have only one high-pressure pathway or port. In some embodiments, the transducer may be connected via wire or wireless to the heads-up display device.

[0010] Additional aspects of the disclosure may include embodiments of a device comprising: a pressure gauge; a whistle; a transducer; a lower high-pressure hose; and an upper high-pressure hose; wherein: the transducer is in fluid communication with the upper and lower high-pressure hoses; the upper and lower high-pressure hoses each comprise an inner high-pressure tube and an outer medium-pressure tube; the transducer comprises a high- pressure pathway and a medium-pressure pathway; and the transducer is operable to sense pressure and transmit a signal to a heads-up display device. In some embodiments, the high- pressure air is operable to pass through the lower hose, through the high-pressure pathway to the transducer and through the upper high-pressure hose to the pressure gauge, and medium- pressure air is operable to pass through the lower high-pressure hose, the medium-pressure pathway, and the upper high-pressure hose to the whistle. In some embodiments, the transducer further comprises a pneumatic switch and a high-pressure sensor. In some embodiments, the transducer further comprises a processor with a signal transmitter, wherein the processer is in communication with the high-pressure sensor. In some embodiments, the high-pressure pathway through the transducer comprises a main through line and a branch line, wherein the branch line is in fluid communication with the pneumatic switch and thereby with the high-pressure sensor. In some embodiments, the device further comprises a mask having a heads-up display device, wherein the mask is in fluid communication with the one or more air cylinders via the pressure reducer and a demand valve.

[0011] Other aspects of the disclosure may include embodiments of a self-contained breathing apparatus comprising: one or more air cylinders/tubes; a mask with a heads-up display device operable to indicate the amount of air remaining in the cylinders; an analog pressure gauge and whistle; and a transducer in fluid communication with the pressure gauge and whistle operable to transmit a signal to the heads-up display device indicating remaining tank capacity based on sensed pressure. In some embodiments, the apparatus further comprises a pressure reducer operable to communicate medium-pressure air. In some embodiments, the pressure reducer may comprise a port for connection of a medium-pressure hose (leading to a demand valve and though to the mask) and a port for connection of a high- pressure hose (operable to transmit high-pressure air from the cylinders and medium-pressure air from the pressure reducer within a high-pressure hose having an inner high-pressure tube and an outer medium-pressure tube). Thus, the pressure reducer may have only on high- pressure port. In some embodiments, the transducer comprises a high-pressure pathway and a medium-pressure pathway, such that high-pressure air from the cylinders is transmitted to the pressure gauge and medium-pressure air for the pressure reducer is transmitted to the whistle. In some embodiments, the apparatus further comprises an upper high-pressure hose and a lower high-pressure hose, each comprising an inner high-pressure tube and an outer medium-pressure tube. In some embodiments, the transducer further comprises a pneumatic switch and a pressure sensor and a processor with signal transmitter, wherein the high- pressure pathway comprises a main through line and a branch line and the branch line is in fluid communication with the pneumatic switch and thereby with the pressure sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] For a more complete understanding of the present disclosure, and for further details and optional advantages thereof, reference is now made to the accompanying drawings, wherein:

[0013] FIG. 1A-1 C illustrate an exemplary embodiment of a self-contained breathing apparatus system comprising a mask with a heads-up display device;

[0014] FIGS. 2A-2B illustrate an exemplary embodiment of a pressure gauge and whistle system;

[0015] FIGS. 3A-3C illustrate embodiments of a transducer system;

[0016] FIGS. 4A-4C illustrate detailed views of an embodiments of the transducer system of FIG. 3C;

[0017] FIGS. 5A-5C illustrate detailed views of an embodiments of the transducer of FIG. 3C;

[0018] FIGS. 6A-6D illustrate detailed views of an embodiments of a transducer body;

[0019] FIGS. 7A-7C illustrate detailed views of an embodiments of a pneumatic switch;

[0020] FIGS. 8A-8B illustrate an embodiment of the transducer system when no air is flowing through the system;

[0021 ] FIGS. 9A-9B illustrate an embodiment of the transducer system when high- pressure air is flowing through the system; and

[0022] FIGS. 10A-10B illustrate an embodiment of the transducer system when high- pressure air and medium-pressure air are flowing through the system. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following brief definition of terms shall apply throughout the application:

[0024] The term "comprising" means including but not limited to, and should be interpreted in the manner it is typically used in the patent context;

[0025] The phrases "in one embodiment," "according to one embodiment," and the like generally mean that the particular feature, structure, or characteristic following the phrase is included in at least one embodiment of the present invention, and may be included in more than one embodiment of the present invention (importantly, such phrases do not necessarily refer to the same embodiment); and

[0026] If the specification states a component or feature "may," "can," "could," "should" or "might" be included or has a characteristic, that particular component or feature is not required to be included or to have the characteristic.

[0027] Generally, Applicants have found that incorporation of a transducer system into a high-pressure hose of a self-contained breathing apparatus (SCBA) may be beneficial to monitoring and indicating the pressure level of air within the SCBA, wherein the high-pressure hose may be coupled to a pressure gauge and optionally a warning whistle. In some embodiments, a transducer may be operable to sense or detect the pressure of high-pressure air flowing through the transducer. Additionally, the transducer may comprise a processor operable to transmit signal referencing the pressure to a heads-up display device (HUD), wherein the HUD may indicate the pressure level to a user of the SCBA.

[0028] FIG. 1A illustrates a SCBA system 100 comprising a mask 102, a demand valve 104 operable to be connected to the mask 102, one or more air cylinders 110, a medium- pressure hose 106 providing fluid communication between the air cylinder(s) 110 and the mask 102 via the demand valve 104 (which may also be known as a second stage reducer), and a pressure reducer 124, operable to reduce the pressure of the air from the cylinders 110, providing fluid communication between the air cylinders 1 10 and the medium-pressure hose 106. In some embodiments, the cylinders 1 10 may comprise high-pressure air at approximately 4500 psi, for example. The pressure reducer 124 may reduce the high-pressure air from the cylinders 1 10 to medium-pressure air of approximately 100 psi, for example. In some embodiments, the demand valve 104 may be operable to reduce the medium-pressure air to approximately atmospheric pressure before delivering the air into the mask 102.

[0029] Additionally, the SCBA system 100 may comprise a harness comprising shoulder straps 108, a belt strap 1 12, and/or a cylinder strap 122. In some embodiments, the SCBA may also comprise a pressure gauge 1 18 and whistle 1 19, wherein the pressure gauge 1 18 and whistle 1 19 may be in fluid communication with the air cylinder(s) 1 10 via a high-pressure hose 120. In some embodiments, the high-pressure hose 120 may be coupled to the cylinders 1 10 via the pressure reducer 124. For example, in some embodiments the pressure reducer 124 may comprise a high-pressure pathway, for the high-pressure hose 120 to provide high-pressure air to the high-pressure gauge 1 18), a first medium-pressure pathway for the medium-pressure hose 106, and a second medium-pressure pathway (to provide medium-pressure air to the whistle). Thus, the pressure reducer 124 of FIG. 1A may be operable to reduce the high-pressure air of the air cylinder(s) 1 10 to medium pressure air, and to transmit (via coupling of the appropriate hoses) high pressure air to the pressure gauge 1 18, medium pressure to the demand valve 104, and medium pressure air to the whistle 1 19. Typically, the high-pressure hose 120 comprises a high- pressure pathway and a medium-pressure pathway, and couples to the pressure reducer 124 so that both high-pressure air and medium-pressure air may be transmitted to the combined high- pressure gauge 1 18 and whistle 1 19. In FIG. 1A, the pressure reducer 124 has only one high- pressure pathway/port (for attachment of the high-pressure hose 120). In some embodiments, the pressure gauge 1 18 and whistle 1 19 may be operable to monitor the pressure of the air in the cylinders 1 10 as well as alert a user of the SCBA if the pressure drops below a pre-set or defined limit.

[0030] Turning now to FIGS. IB and 1 C, a detailed view of a mask 102 and demand valve 104 embodiment are shown, wherein the mask 102 may comprise a heads-up display (HUD) 140. In some embodiments, the HUD 140 may comprise one or more lights 142 (shown in FIG. 1C) visible to the user when wearing the mask 102. In some embodiments, the one or more lights 142 may comprise a plurality of LED lights, wherein the LED lights may comprise one or more of: one color, multiple colors, changing colors, flashing LEDs, or a combination. In some embodiments, a HUD 140 may be used to alert a user of the SCBA 100 of the pressure levels in the cylinders 1 10. In other embodiments, the HUD 140 may alert the user when pressure levels reach a pre-defined level. In some embodiments, the HUD 140 may be used in combination with the pressure gauge 1 18 and whistle 1 19. In some embodiments, the HUD 140 may comprise an audible alert 144 as well as a light sensor 146 operable to modify the brightness of the LEDs 142 according to ambient light conditions.

[0031 ] Regardless of the specific configuration, embodiments typically provide high- pressure air from the cylinder(s) 1 10 and medium-pressure air (after reduction by the pressure reducer 124) to the high-pressure hose 120. FIGS. 2A-2B illustrates exemplary high-pressure 204 and medium-pressure air flow 202 to the pressure gauge 1 18 and whistle 1 19. In FIG. 2A, the high-pressure air 204 may be above approximately 55 bar, and may be flowing through the pressure reducer 124 and high-pressure tube 120 to the pressure gauge 1 18. In FIG. 2B, the high-pressure air may be below approximately 55 bar, and the medium-pressure air 202 may be activated to flow through the pressure reducer 124 and high-pressure hose 120 to the whistle 119.

[0032] FIGS. 3A-3C illustrate a modification of a standard high-pressure hose 120 of an exemplary SCBA 100, wherein a transducer system 300 may be incorporated into the SCBA 100. In some embodiments, the transducer system 300 may comprise a high-pressure transducer 320, wherein the transducer 320 may be positioned between the cylinders 1 10 and the pressure gauge 1 18 and whistle 1 19. In the embodiment shown in FIG. 3C, the high- pressure hose 120 may be replaced by an upper high-pressure hose 302 and a lower high- pressure hose 304, and the transducer 320 may be positioned between the upper high-pressure hose 302 and the lower high-pressure hose 304. In the embodiment shown in FIG. 3C, the upper high-pressure hose 302 may be positioned between the transducer 320 and the combined pressure gauge 1 18 and whistle 1 19, and the lower high-pressure hose 304 may be positioned between the pressure reducer 124 and the transducer 320. In some embodiments, the upper high-pressure tube 302 and the lower high-pressure tube 304 may comprise steel composite tubing.

[0033] FIG. 4A illustrates an exploded view of the transducer system 300 comprising the transducer 320, upper high-pressure hose 302, lower high-pressure hose 304, and combined pressure gauge 1 18 and whistle 1 19 (although in some embodiments a separate pressure gauge and whistle might be used). In some embodiments, the transducer 320 may be coupled to the upper and lower high-pressure hoses via assembly screws 402. In some embodiments, the transducer 320 may comprise and upper connection port 404 operable to receive at least a portion of the upper high-pressure hose 302. Additionally, the transducer 320 may comprise a lower connection port 406 operable to receive at least a portion of the lower high-pressure hose 304. In some embodiments, the transducer system 300 may comprise one or more connectors operable to connect the components of the system 300. For example, a first connector 420 may be operable to connect the upper high-pressure hose 302 to the transducer 320 through the upper connection port 404. Additionally, a second connector 422 may be operable to connect the lower high-pressure hose 304 to the transducer 320 through the lower connection port 406. In some embodiments, a third connector 424 may be operable to connect the lower high- pressure hose 304 to the pressure reducer 124, as described in FIG. 1. Such connectors would typically mesh with the corresponding parts to form a sealed (e.g. air tight) connection that may be removably connected.

[0034] FIGS. 4B-4C illustrate an exemplary embodiment of the upper high-pressure hose 302 and combined pressure gauge 118 and whistle 119, and the lower high-pressure hose 304. In some embodiments, the upper high-pressure hose 302 may be operable to transmit both high-pressure and medium-pressure air, wherein the upper high-pressure hose 302 may comprise an inner high-pressure tube 410 and an outer medium-pressure tube 412. In some embodiments the inner high-pressure tube 410 may comprise a pressure resistant metal material, and the outer medium-pressure tube 412 may comprise a rubber material. In some embodiments, the lower high-pressure hose 304 may also be operable to transmit both high- pressure and medium-pressure air, wherein the lower high-pressure hose 304 may comprise an inner high-pressure tube 414 and an outer medium-pressure tube 416. In some embodiments the inner high-pressure tube 414 may comprise a pressure resistant metal material, and the outer medium-pressure tube 416 may comprise a rubber material.

[0035] FIG. 5A illustrates an exploded view embodiment of the high-pressure transducer 320. The transducer 320 may comprise a housing 502 with an upper cover 504 and lower cover 506, wherein the covers may be held to the housing 502 when assembled by screws 505 and 507 for example. In some embodiments, the transducer 320 may comprise a transducer body 512, wherein the body 512 may be operable to hold the components in place within the transducer 320. Additionally, the transducer body 512 may comprise one or more air pathways as well as connection ports 404 and 406. In some embodiments, a high-pressure sensor 514 may be coupled to the transducer body 512, operable to detect the pressure of the air passing though one or more of the pathways of the body 512 (for example, operable to detect the pressure of the air in the high-pressure pathway). Typically, the pressure sensor 514 may translate mechanical pressure readings (for example based on compression of a spring) into corresponding electrical signals indicative of the pressure reading. In some embodiments, the transducer 320 may comprise a processor 510, and in the embodiment of FIG. 5 A, the processer may comprise a printed circuit board (PCB) assembly. The PCB assembly 510 typically would be coupled to the high-pressure sensor 514, such that the PCB assembly 510 may be operable to process the pressure readings from the sensor 514 and generate signals based on the detected pressure. For example, the PCB assembly 510 may be operable to convert pressure readings from the sensor 514 into signals denoting the amount of air remaining in the cylinders, and then to communicate with the HUD of the SCBA. In some embodiments, the transducer 320 may comprise a battery 508 which may be held in the housing 502 by a battery cover cap 509. In some embodiments, the transducer 320 may comprise a pneumatic switch 516 which may be coupled to the PCB assembly 510 as well as the battery 508, such that the pneumatic switch 516 is operable to control the connection between the battery 508 and the PDB assembly 510. In some embodiments, the pneumatic switch 516 may be in contact with or comprise a piston assembly 518, wherein the piston assembly 518 may be operable to move between at least two positions, wherein one position may activate the pneumatic switch 516 and another position may deactivate the pneumatic switch 516. So for example, in FIG. 5 A, air from the high-pressure pathway 530 (through the transducer body 512) might operate on the pneumatic switch 516 (so that the battery 508 only provides power to the sensor 514 and/or processor 510 when pressure is present). And in FIG. 5 A, when the pneumatic switch 516 is activated, the high-pressure pathway would be in fluid communication with the pressure sensor 514 (which would convert the mechanical pressure to an electrical signal for analysis and transmission by the processor).

[0036] FIG. 5B illustrates an embodiment of the transducer 320 and the wired connections between the PCB assembly 510, high-pressure sensor 514, battery 508, and pneumatic switch 516. Typically, the positive end of the battery 508 may be connected to the pneumatic switch 516 with a first positive wire 520. The positive connection may be continued past the pneumatic switch 516 to the PCB assembly 510 via a second positive wire 521. In some embodiments, the PCB assembly 510 may be coupled to the negative end of the battery 508 via a negative wire 522. The positive wires 520 and 521 may be coupled to the pneumatic switch 516 such that when the switch 516 is activated, the circuit is completed and power is provided from the battery 508 to the PCB assembly 510, and when the switch 516 is deactivated, no power is provided from the battery 508 to the PCB assembly 510. In some embodiments, the PCB assembly may also be coupled to the high-pressure sensor 514 via one or more signal wires 524 operable to transmit the sensor readings from the sensor 514 to the PCB assembly 510 (as electrical signals).

[0037] Additionally, FIGS. 5B and 5C illustrate exemplary air pathways through the transducer body 512, wherein FIG. 5C is a view of the transducer 320 as seen along the line C- C of FIG. 5B. The body 512 may comprise a high-pressure pathway 530 between the connection ports 404 and 406, wherein the high-pressure pathway 530 may also comprise a branch 532. In other words, the high-pressure pathway may comprise a mine line 530 (between the port ends 404 and 406) and a branch line 532 (leading to the pneumatic switch 516 and thereby to the pressure sensor 514). The body 512 may also comprise a medium-pressure pathway 534 between the connection ports 404 and 406.

[0038] FIGS. 6A-6D illustrate an exemplary transducer body 512 in more detail. The body may comprise a cavity 602 between the high-pressure sensor 514 and the piston assembly 518/pneumatic switch 516. This cavity 602 may be in selective fluid communication with the branch 532 of the high-pressure pathway 530, such that the cavity 602 may fill with air from the branch 532 when high-pressure air flows through the high-pressure pathway 530. In other words, the cavity 602 of FIGS. 6B-C may only be in fluid communication with the branch 532 when the pressure in the branch 532 is sufficient (of course, in other embodiments, the cavity 602 and/or pressure sensor 514 may always be in fluid communication with the branch 532 and/or high-pressure pathway 530). In some embodiments, the sensor 514 may be operable to sense the pressure of the air within the cavity 602 (which in some embodiments may be part of the branch line 532). In some embodiments, the piston assembly 518 may be operable to move between at least two positions, wherein a first position is shown in FIG. 6B and a second position is shown in FIG. 6C. As shown by the separation measurement 604, the piston 518 may be pushed to a higher second position if the branch 532 is filled with high-pressure air (with the pressurized air in the branch line 532 acting on the piston). In some embodiments, the piston assembly 518 may be spring loaded, wherein the spring 608 may bias the piston 518 toward the first position shown in FIG. 6B. Therefore, if no air is filling the branch 532, the piston 518 may be in the first position, but when sufficient pressure fills the branch 532 the piston 518 would move to the second position. In some embodiments, if the pressure within the cavity is less than about 10 bar, the piston 518 may be in the first position, while pressure above about 10 bar (for example) might provide the mechanical force to move the piston 518 into the second position. When the piston 518 is in the second position, the cavity 602 may be in fluid communication with the branch 532 (and thereby with the high-pressure pathway 530). In some embodiments, when the piston 518 is in the second position, shown in FIG. 6C, the piston 518 may engage the pneumatic switch 516 (which in turn may activate power to the processor 510 and/or sensor 514). FIG. 6D is a view of the transducer body 512 as seen along the line D-D of FIG. 6B. In FIG. 6D, the medium-pressure pathway 534 can be seen. The medium-pressure pathway 534 is oriented so that it does not interfere with the high-pressure pathway 530 or the branch 532, but provides a by-pass through the body 512 so that medium- pressure air from the lower hose connection 406 may pass through to the upper hose connection 404.

[0039] FIGS. 7A-7C illustrate the pneumatic switch 516 in more detail. In some embodiments, the pneumatic switch 516 may comprise a first wire connector 702 and a second wire connector 704. In some embodiments, the first wire connector 702 may be connected to the first positive wire 520 and the second wire connector 704 may be connected to the second positive wire 521, as illustrated in FIG. 5B. In some embodiments, the pneumatic switch 516 may comprise a metal plate 706 coupled to the second wire connector 704. The metal plate 706 may be operable to bend and/or move in a vertical direction between at least two positions, wherein the first position is shown in FIG. 7B and the second position is shown in FIG. 7C. In some embodiments, the switch 516 may also comprise a spring 708, wherein the spring may be operable to bias the metal plate 706 toward the first position of FIG. 7B. In some embodiments, the metal plate 706 may be moved to the second position of FIG. 7C if the piston assembly 518 is raised, wherein the piston 518 may compress the spring 708 allowing the metal plate 706 to be raised to the second position. In some embodiments, when the metal plate 706 is in the first position, it may not be in contact with the first wire connector 702, but when moved to the second position, the plate 706 contacts the first wire connector 702. Therefore, when the metal plate 706 is raised to the second position, the wired connection is completed and the PCB assembly 510 receives power from the battery 508, as shown in FIG. 5B.

[0040] FIGS. 8A-8B illustrate an embodiment of the transducer system 300 when no air is flowing through the hoses 302 and 304 or the transducer 320 (as shown by the pressure gauge 118 in FIG. 8A). The piston assembly 518 may be in the first position, and therefore the pneumatic switch 516 may be deactivated, such that no power is supplied from the battery 508 to the PCB assembly 510. This may save the store of power in the battery 508 when the transducer system 300 is not in use.

[0041] FIGS. 9A-9B illustrate an embodiment of the transducer system 300 when high- pressure air is flowing through the system 300 (as shown by the pressure gauge 118 in FIG. 9A). For example, the high-pressure air may flow through the inner high-pressure tube 414 of the high-pressure hose 304, into the high-pressure pathway 530 of the transducer body 512, out of the transducer 320 through the high-pressure tube 410 of the high-pressure hose 302, and then to the pressure gauge 118. In some embodiments, the high-pressure air may come from the high-pressure cylinders 110 (for example, transmitted via the pressure reducer 124 through the lower high-pressure hose 304). Additionally, the high-pressure air may enter the branch 532 of the high-pressure pathway 530, and interact with the piston 518 of the pneumatic switch 516, pushing the piston assembly 518 into the second position. This may complete the wired circuit, allowing the battery 508 to power the PCB assembly 510. Additionally, movement of the piston 518 into its second position may bring the cavity 602 into fluid communication with the branch 532, such that the pressure sensor 514 would be in fluid communication with the high-pressure pathway 530 and detect the air pressure from the air cylinders 110. Pressure readings from the sensor 514 may be converted into signals which may be translated and/or transmitted by the PCB assembly 510 to an HUD 140, shown in FIG. 2, via wire, wireless, Bluetooth, etc. Additionally, the high-pressure air may pass through the high-pressure tube 410 of the upper high-pressure hose 302 to the pressure gauge 118. Therefore, the pressure level of the high-pressure air may be reflected in the pressure gauge 118 as well as by the HUD 140. Thus, embodiments may provide heads-up display of the pressure (or remaining air in the cylinders) and an analog pressure reading on the pressure gauge 118.

[0042] FIGS. 10A-10B illustrate an embodiment where the pressure of the high-pressure air has dropped below a predefined level, such as about 55 bar, for example (as shown by the pressure gauge 118 of FIG. 10A). The warning whistle 119 may be activated in such instances, with medium-pressure air then passing through the medium-pressure tube 416 of the lower high-pressure tube 304, into the medium-pressure pathway 534 of the transducer 320, and through the medium-pressure tube 412 of the upper high-pressure hose 302 to the whistle 119. In some embodiments, the high-pressure tube 410 may continue to be in fluid communication with the pressure gauge 118 even as the warning whistle 119 sounds, offering an analog pressure reading, for example. In some embodiments, the high-pressure tube 410 of the upper high-pressure hose 302 may be in fluid communication with the pressure gauge 118, while the medium-pressure tube 412 of the upper high-pressure hose 302 may be in fluid communication with the warning whistle 119. Additionally, the PCB assembly 510 may continue to communicate with the HUD 140, wherein the HUD 140 may indicate low pressure at a predefined minimum value. In some embodiments, the minimum value of the HUD 140 may be equal to that of the warning whistle 119, while in other embodiments, the minimum value may vary between the warning whistle 119 and the HUD 140. Additionally, the HUD 140 may comprise multiple levels of indication, wherein the indications may correspond to multiple pressure levels. In some embodiments, the PCB assembly 510 may communicate with the HUD 140 continuously and/or periodically.

[0043] In some embodiments, a pressure transducer and HUD may be used to retrofit or upgrade existing SCBA. An exemplary method might include providing a pressure transducer and HUD, integrating the pressure transducer into the high-pressure hose leading from the pressure reducer to the pressure gauge and/or whistle (for example, a combine pressure gauge and whistle), adding the HUD to a SCBA mask, wherein the pressure transducer detects the high-pressure air in the high-pressure hose and transmits a signal to the HUD. Typically, the pressure transducer would pass high-pressure air through to the pressure sensor and medium pressure air through to the whistle. In some embodiments, integrating the pressure transducer into the high-pressure hose might require replacing the existing high-pressure hose with an upper and lower high-pressure hose, wherein the lower high-pressure hose would connect to (the high-pressure pathway of) the pressure reducer, the pressure transducer would connect to the lower high-pressure hose, the upper high-pressure hose would connect to the transducer, and the pressure gauge/whistle would connect to the upper high-pressure hose. Typically, the standard pressure reducer would not have to be modified or replaced, and the pressure reducer would have only one high-pressure pathway/port. Thus, the transducer would be installed mainly by removing the standard high-pressure hose and replacing it with a lower high- pressure hose, a transducer, and an upper high-pressure hose. In some embodiments, the transducer would also be connected (via wire or wireless, for example) to the HUD. The pressure transducer would typically have a high-pressure pathway and a medium-pressure pathway, and both the upper and lower high-pressure hoses would comprise an inner high- pressure tube and an outer medium-pressure tube.

[0044] The figures discussed above provide examples of various exemplary devices, systems, and techniques and ways to make and use such devices. These illustrations are merely exemplary. The scope of the present disclosure extends beyond the specific examples set forth above, capturing the full range of the inventive concept (and including all equivalents).

[0045] While various embodiments in accordance with the principles disclosed herein have been shown and described above, modifications thereof may be made by one skilled in the art without departing from the spirit and the teachings of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the disclosed embodiments are also within the scope of this disclosure. The embodiments described herein are representative only and are not intended to be limiting. Many variations, combinations, and modifications are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited by the description set out above, but is defined by the claims which follow, that scope including all equivalents of the subject matter of the claims. Furthermore, any advantages and features described above may relate to specific embodiments but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages or having any or all of the above features.

[0046] Additionally, the section headings used herein are provided for consistency with the suggestions under 37 C.F.R. 1.77 or to otherwise provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically and by way of example, although the headings refer to a "Field of the Invention," the claims should not be limited by the language chosen under this heading to describe the so-called field. Further, a description of a technology in the "Background" is not to be construed as an admission that certain technology is prior art to any invention(s) in this disclosure. Neither is the "Summary" to be considered as a limiting characterization of the invention(s) set forth in issued claims. Furthermore, any reference in this disclosure to "invention" in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. The term "comprising" as used herein is to be construed broadly to mean including but not limited to, and in accordance with its typical usage in the patent context, is indicative of inclusion rather than limitation (such that other elements may also be present). In all instances, the scope of the claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings set forth herein.