Hose connection system for narially sensitive diagnostic devices

Hose connection system for narially sensitive diagnostic devices. At least some of the illustrative embodiments are systems including a test device and a nasal cannula. The test device includes a first port configured to sense an attribute of airflow, and a second port configured to sense an attribute of airflow. The nasal cannula includes a first hose configured to fluidly couple on a device-end to the first port (and the first hose configured to fluidly couple between the first port and a first naris of a patient), and a second hose configured to fluidly couple on a device-end to the second port (and the second hose configured to fluidly couple between the second port and a second naris of the patient). The nasal cannula is configured such that the first hose only couples to the first port and the second hose only couples to the second port.

BACKGROUND

Sleep disordered breathing is common throughout the population, and some sleep disorders may be attributable to disorders of the respiratory tract. Sleep apnea may be a disorder where a person temporarily stops breathing during sleep. A hypopnea may be a period of time where a person's breathing becomes abnormally slow or shallow. In some cases, a hypopnea precedes an apnea event. Snoring may be caused by mucus build up in the upper respiratory tract, and/or excessive tissue causing cyclic full or partial blockages of the nose. Other breathing difficulties, not necessarily related to sleep but which breathing difficulties become more pronounced during sleep, may be caused by full or partial blockages of the nares, such as by a tumor or polyp.

Sleep disordered breathing and other breathing difficulties may be diagnosed in a sleep lab, or possibly by a device which the patient takes home and wears throughout the day or during sleep. For a proper diagnosis, particularly in the case of a tumor or polyp, the various ports of a test device need to be coupled to the naris for which they were intended; however, currently available nasal cannulas have device-ends (as opposed to patient-ends) that are identical and easily switched when being coupled to a test device.

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description and claims to refer to particular system components. However, manufacturing companies may refer to various components by different names. This document does not intend to distinguish between components that differ in name but not function.

DETAILED DESCRIPTION

FIG. 1illustrates a system1000in accordance with embodiments of the invention. In particular,FIG. 1illustrates a test device10. The test device10may be a device for sensing airflow used in a dedicated sleep lab or a hospital, or the test device10may be a portable possibly battery operated) device that a patient uses in their home which is used as an initial diagnostic aid in diagnosing breathing difficulties. The test device10may be, for example, a device such as described in issued U.S. Pat. No. 7,066,180, titled “Method and System for Measuring Airflow of Nares,” which patent is incorporated by reference herein as if reproduced in full below.

The individual fluid couplings between the test device10and the patient12may be by way of a bifurcated nasal cannula20, such a cannula having two fluidly independent pathways running between the test device10and the patient12. The patient's right naris fluidly couples to a right naris port16and the left naris fluidly couples to a left naris port18.

Still referring toFIG. 1, the test device10in accordance with at least some embodiments of the invention has the ability to log information about the absolute and/or relative inspiratory and expiratory airflow. The information regarding the inspiratory and expiratory airflow may be helpful in diagnosing certain ailments (e.g., existence of a tumor or polyp in a particular naris, head position dependent valve collapse in a particular naris). For the log to be most beneficial in diagnosis, the output port16for the right naris should be coupled to the right naris, and the output port18for the left naris should be coupled to the left nails. In accordance with at least some embodiments, the test device10and the bifurcated nasal cannula20work together to ensure that the hose for the right nails only couples to the outlet port16for the right naris, and the hose for the left naris only couples to the outlet port18for the left naris.

Ensuring the proper coupling of the bifurcated nasal cannula20and the test device10may take many forms. In some embodiments, each hose of the bifurcated nasal cannula has a device-end (i.e., the end that couples to the test device) fitting that mates only with the appropriate outlet port.FIG. 2illustrates a system where the device-end fittings ensure proper orientation. In particular,FIG. 2illustrates a partial view of an exterior24of a test device10. The illustrative exterior has two outlet ports16and18, which in these embodiments comprise apertures26and28. The apertures26and28fluidly couple to devices internal to the test device10, such as pressure sensors and/or flow sensors.FIG. 2also illustrates a portion of the bifurcated nasal cannula20comprising a first hose30and a second hose32. Each of the hoses30and32have a device-end fitting34and36respectively. As illustrated inFIG. 2, the device-end fitting34is configured to fluidly couple to the aperture26, but because of the difference in aperture shape the device-end fitting34will not couple to the aperture28. Likewise, the device-end fitting36is configured to fluidly couple to the aperture28, but because of the difference aperture shape the device-end fitting36will not fluidly couple the aperture26. In this way, the bifurcated nasal cannula20cannot be fluidly coupled to the test device10in a reverse order. WhileFIG. 2shows an illustrative square aperture26and circular aperture28(and corresponding device-end fittings34and36), other shapes and configurations may be equivalently used. For example, the test device10may have one male press-fit (Luer) fitting and one female Luer fitting, with the bifurcated nasal cannula having mating Luer fittings. Any structural differences between the two hose connections that reduces the possibility of misconnecting hoses of the bifurcated nasal cannula20to the test device10may be equivalently used.

FIG. 3illustrates alternative embodiments that ensure proper coupling of the bifurcated nasal cannula20to the test device10. In particular,FIG. 3illustrates a partial view of the exterior24of the test device10. The illustrative exterior has two outlet ports16and18, which in these embodiments comprises male connections40and42, respectively. Female connections may be equivalently used. The illustrative exterior24also has a key aperture44. The connections40and42couple one each devices to internal to the test device10, such as pressure sensors and/or flow sensors.FIG. 3also illustrates a portion of the bifurcated nasal cannula20comprising a first hose30and second hose32. A bracket46mechanically (though not fluidly) couples the hoses30and32together on the device end48. Each of the hoses30and32has a device-end fitting50and52, respectively; however, the device-end fittings50and52may be similar in these embodiments because the bracket46and a tab54work together with the aperture44in the test device10to ensure that the house is coupled in only one orientation.

As illustrated inFIG. 3, the key aperture44is positioned off center with respect to the outlet ports16and18. Likewise, the tab54coupled to the bracket46is positioned off center with respect to the bracket46. In this way, the device end48of the hose system20couples the hoses30and32to their respective outlet ports16and18in only one orientation—the orientation where the tab54extends into the key aperture44. If a user attempts to fluidly couple the hoses30and32to the test device in a reverse orientation, the key aperture44will not align with the tab54, and thus the hose system20will not fluidly couple to the test device10. The long dimension of the key aperture44, and correspondingly the long dimension of the tab54, may be equivalently oriented at any angle. In alternative embodiments, the key aperture44and the tab54may equivalently use other corresponding shapes (e.g. circular, square, hexagonal), so long as the key aperture44and tab54allow the hose system20to fluidly couple to hoses30and32to the ports16and18in only one orientation. Moreover, the key aperture44and tab54need not be disposed between the outlet ports16and18, and thus the key aperture44and the tab54may be equivalently above, below or outside the outlet ports16and18so long as the hose system20couples to the outlet ports16and18in only one orientation. Further still, the key aperture44and tab54may be centered between the ports, but the shape of the key aperture44and tab54may enable coupling in only one orientation.

When using test device10as a diagnostic aid, the pressures and/or airflows sensed may be relative. That is, for example, if measuring pressure as indicative of a patient's respiratory function, the pressure in each tube of the bifurcated nasal cannula is created by air being hydraulically forced into each tube during exhalation. Likewise, lower pressure associate with inhalation is created by air flowing past the patient end of the nasal cannula into the patient's nares. The amount of pressure created in each case may be dependent not only upon the respiratory effort of the patient, but also on characteristics of the hoses (e.g., inside diameter), and thus identifying the manufacturer/type of bifurcated nasal cannula may be important. Likewise in situations where airflow through the nasal cannula is sensed, exhalation by the patient causes airflow through each tube and out an atmospheric vent of the test device. Inhalation draws air through each tube. The amount of airflow, and thus the amount sensed by the test device, may be dependent not only upon respiratory effort of the patient, but also on characteristics of the hoses (e.g., internal diameter, length), and thus identifying the manufacture/type of bifurcated nasal cannula may be important.

FIG. 4illustrates embodiments where the bifurcated nasal cannula20identifies its manufacturer and/or type. In particular, the tab54of the bracket46has features that identify the bifurcated nasal cannula to which the hoses30and32couple. The term “features” in this specification and in the claims is used broadly to encompass not only physical features (e.g., aperture60or notch62), but the term features also comprises any mechanism that identifies the nasal mask (e.g., embedded electronic device64). The embedded electronic device64in some embodiments is a serial read only memory (ROM) which electronically couples to and communicates with a processor of the bilateral positive airway pressure device by way of electrical contacts66. In alternative embodiments, the embedded electrical device64is a radio frequency identification (RFID) tag which is read by the bilateral positive airway pressure device. In yet further alternative embodiments, the tab54has identifying indicia on its outer surface, such as a color coding scheme or bar code, that is read by the processor of the test device10. Notice also that in addition to supporting the features which identify the nasal cannula, the tab54can also serve the purpose of ensuring that the cannula couples to the test device in only one orientation, as discussed above.

FIG. 5illustrates a circuit70which couples to an illustrative processor73. The processor73performs, in whole or in part, the diagnosis or pre-diagnosis performed by the test device10. The circuit70illustrated inFIG. 5may be part of the test device10, and is enabled for use with features of the tab54being aperture60and/or notch62. In particular, the circuit70comprises light emitting diodes72and74. Electrical current supplied from source76flows through the diodes creating light (not necessarily visible). The light from the light emitting diode72and74is configured to shine across the aperture, the aperture illustrated by dashed line44. The circuit70further comprises photo diodes76and78. Photo diodes76and78are arranged to be in operational relationship with the light emitting diode72and74respectively. While the illustrative circuit ofFIG. 5shows only two light detection paths, any number of light emitting diodes and photo diodes implementing any number of light detection paths may be equivalently used. As the tab54is inserted through the key aperture44, the light path between the corresponding light emitting diode and photo diode is selectively broken, and the type of nasal cannula to which the hose system20is attached may be identified by the pattern of broken and unbroken lights paths. For example, if the light path between the light emitting diode72and photo diode76is broken, the photo diode76ceases conducting, and therefore the processor73sees a low voltage or logic zero input. Likewise, if the tab54has an aperture60or notch62such that the light path is unbroken in spite of the presence of the tab54, the photo diode conducts and the processor73sees a high voltage or a logic one. In the illustrative case ofFIG. 5having two light paths, three different nasal cannulas may be identified (assuming that two unbroken light paths indicate that no cannula has been connected to the test device).

FIG. 6illustrates alternative embodiments where the feature used to identify the nasal cannula is an RFID tag. In particular, the system80comprises a tag antenna82coupled to a RFID reader84. The RFID reader84and tag antenna82work together to interrogate an RFID tag coupled on the device end of a nasal cannula. In some embodiments, the RFID tag may reside on the tab54, and thus the antenna82may be in operational relationship to the aperture44. In other embodiments, the RFID tag may reside at any location proximate to the device-end of the cannula. Once the data payload of the RFID tag is read by the RFID reader, the RFID reader passes the information along to the processor73which may then compensate readings based on the physical characteristics of the cannula.

The various embodiments discussed to this point are based on use of a bifurcated (two-tube) cannula. In alternative embodiments, the test device10may also monitor airflow through a patient's mouth, and thus a three-tube cannula may be used. U.S. Pat. No. 7,007,694 titled “Nasal Cannula,” assigned to the same assignee as this specification and incorporated by reference herein as if reproduced in full below, is illustrative of a nasal cannula that may be used to monitor respiratory airflow through a patient's nares and mouth. It may as important to properly couple the tube associated with the mouth to a proper port on the test device10.FIG. 7illustrates system where device-end fittings of a three-tube cannula ensure proper orientation. In particular,FIG. 7illustrates a partial view of an exterior24of a test device10. The illustrative exterior in these embodiments has three outlet ports16,18and90, which in these embodiments comprise apertures26,28and92. The apertures26,28and92fluidly couple to devices internal to the test device10, such as pressure sensors and/or flow sensors.FIG. 7also illustrates a portion of the bifurcated nasal cannula100comprising a first hose30, a second hose32and a third hose94. Each of the hoses30,32and94has a device-end fitting34,36and96, respectively. As illustrated inFIG. 7, the device-end fitting34is configured to fluidly couple to the aperture26, but because of the difference in aperture shape the device-end fitting34will not couple to the apertures28or92. Likewise, the device-end fitting36is configured to fluidly couple to the aperture28, but because of the difference aperture shape the device-end fitting36will not fluidly couple the aperture26or92. Finally, the device-end fitting96is configured to fluidly couple to the aperture92, but because of the difference in aperture shape the device-end fitting96will not fluidly couple to apertures26and28. In this way, the three-tube cannula100cannot be fluidly coupled to the test device10in an incorrect order. WhileFIG. 7shows an illustrative aperture shapes, other shapes and configurations may be equivalently used.

FIG. 8illustrates alternative embodiments that ensure proper coupling of the three-tube cannula100to the test device10. In particular,FIG. 8illustrates a partial view of the exterior24of the test device10. The illustrative exterior has three outlet ports16,18and102, which in these embodiments comprises male connections40,42and104, respectively. Female connections may be equivalently used. The connections40,42and104couple one each devices to internal to the test device10, such as pressure sensors and/or flow sensors.FIG. 8also illustrates a portion of the three-tube nasal cannula100comprising a first hose30, second hose32and third hose106. A bracket108mechanically (though not fluidly) couples the hoses30,32and106together on the device-end48. Each of the hoses30,32and106has a device-end fitting50,52and110, respectively; however, the device-end fittings may be similar in these embodiments because the bracket108and placement of the hoses on the bracket108work together with the test device10to ensure that the house is coupled in only one orientation. In particular, the middle hose is offset from the center such that cannula100couples to the test device10in only one orientation. Although illustrativeFIG. 8shows the hoses to be co-planar, in alternative embodiments the hoses may reside at different elevations, and indeed the different elevations may ensure that the hoses couples to the test device in only one orientation. Moreover, although a tab on the bracket and corresponding aperture in the test device are not strictly needed in the embodiments ofFIG. 8, a tab may nonetheless be used as the mechanism to identify the cannula, as discussed above.

The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. For example, ensuring the hoses connect in only one orientation may involve each connection comprising a male-type connector having a different diameter. Thus, while one hose may physically fit over a connector designed for a smaller diameter hose, the larger diameter hose will not seal, thus informing the user inappropriateness of the connection. It is intended that the following claims be interpreted to embrace all such variations and modifications.