MXPA99009881A - Peak flow monitor - Google Patents

Abstract

A peak flow monitoring device includes first (12) and second (14) body shells that are rotatably engageable with each other to define a resonance chamber (46) formed with a vent outlet (26). The body shells are lockable to one another in increments to set an occluder (20) at a predetermined incremental variation of the vent outlet size. The locking mechanism comprises multiple splines (28) formed on one of the body shells and a key (32) movably mounted on the other body shell, the key (32) being adapted for axial movement into the grooves between the splines (28) to lock the body shells (12, 14) to one another.

Description

PEAK FLOW MONITOR BACKGROUND OF THE INVENTION This invention relates to a peak expiratory flow verification device. The peak expiratory flow rate (PEFR = Peak Expiratory Flow Rate) is a measure of lung performance, which can be determined easily and precisely by various devices. The PEFR verification has achieved acceptance as a means to verify the asthma status, since it can be recorded reliably by cooperating subjects, without the help of technically skilled personnel and with the use of simple portable devices. an amount of these devices is described in PCT / GB96 / 01251. SUMMARY OF THE INVENTION According to this invention, a flow verification device comprises a substantially hollow body formed with a passage for fluid flow incorporating a signal generator, adapted to generate a signal in dependence of the achievement of a flow expense of fluid in predetermined volume through the signal generator, the body comprises first and second body shells, which are rotatably coupled together to define a resonance chamber formed with a REF: 31841 vent outlet, the first body shell is formed with an inlet consisting of a nozzle and the passage for fluid flow that extends at least between the nozzle and the vent outlet, the device includes an occluder that is adapted to seal the vent outlet in a greater or lesser proportion depending on the rotational position of the body shells with each other and the body shells include an enclosure mechanism washing by means of which the body shells can be locked together in increments to adjust the occluder to a predetermined incremental variation of the ventilation outlet size, characterized in that the enslavement mechanism comprises multiple grooves formed in one of the body shells and a key movably mounted on the other body shell, the key is adapted for axial movement within the grooves between the grooves, to lock the body shells with each other. In the preferred form of the invention, the resonance chamber, with the outlet there formed, can be defined substantially by the second body shell and the occluder can be incorporated into the first body shell and adapted, when the body shells are coupled to extending within the resonance chamber to occlude the ventilation outlet in a greater or lesser proportion depending on the rotational position of the body shells relative to each other. In this form of the invention, the first body shell can be referred to as an inlet shell and the second body shell can be referred to as an outlet shell. The body shell are the key of preference is formed with a guide, with the key that is mounted on a key carrier that is slidably mounted on the guide. In this form of the invention, the key carrier can include a locking pin that is adapted for insertion and retention in a complementary locking opening formed in the body shell. The occluder is preferably cylindrical and adapted, when the shells are coupled, to extend within the outlet shell, the edge extending inward from the occluder is spirally shaped and adapted to occlude ventilation in a greater or lesser proportion depending on the rotational position of the shells with each other. The body shells can be interconnected by supplying, in one of the body shells, an internal axial spindle and in the other body shell, a rod assembly into which the rod can be rotatably mounted. The stem and the mounting are preferably coupled in such a manner that axial detachment of the rod and assembly are avoided instead of destruction of the verification device. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Figure 1 is an exploded perspective view of the verification device according to the invention, seen from the output end of the device; Figure 2 is a perspective view of the device of Figure 1, seen from the input end of the device; Figure 3 is a diagrammatic section on a line 3-3 of Figure 1; Figure 4 is a diagrammatic section on a line 4-4 of Figure 2; Figure 5 is an end elevation (partially in section) of the device of the invention, which is seen from its outlet end (without a sound generator); Figure 6 is a lateral elevation of the shell of the outlet body of the device of Figure 1; Figure 7 is an end elevation of a part of a locking mechanism of the device of Figure 1; Figure 8 is a plan view in the part of the locking mechanism illustrated in Figure 7; Y Figure 9 is a partial bottom plan view partly of the locking mechanism illustrated in Figure 7. BRIEF DESCRIPTION OF THE MODALITIES OF THE INVENTION The verification device of the invention is not a flow meter in the sense that it does not measure absolute flow to through the device. On the contrary, it is a device intended as a peak expiratory flow expenditure threshold monitor (PEFR) of a subject. This is done by verifying the achievement or otherwise of a predetermined PEFR threshold by the subject. In this sense, the monitor of this invention is a threshold monitor since it verifies the achieved PEFR of the subject, in comparison with a diagnostic threshold. The predetermined PEFR is a diagnostic threshold that will depend on the predetermined treatment protocol for the subject after measurement of the anticipated or predicted PEFR of the subject. The monitor 10 of the invention can be seen to comprise a pair of interengaging body shells 12, 14 and a sound generator constituted by a tongue structure 16. The shell 12 is essentially an entrance shell and the shell 14 is a shell of output, which are joined together in the manner described below. In practice, the subject sucks as much as possible, and then expires or blows through the cylindrical tube constituting the nozzle 18 at the inlet end of the inlet shell 12. The subject is normally instructed not to cough or allow Explosive expiratory flow such as spitting, coughing or interrupted flow, resulting from clogging with the nozzle tongue, but as will be seen below, the verification device 10 of the invention is designed to minimize possible impressions arising from this explosive expiratory flow. The outlet shell 14 is constituted by an external wall 24 circumscribing a resonance chamber 46 formed with a ventilation opening 26, which extends axially along the outer shell 14. A central housing in the shape of a horn or horn 22 for the tongue structure 16 extends axially within the resonance chamber 46. The shells 12, 14 are intended to interconnect with each other and the tongue structure 16 is pressed into the horn-shaped housing 22.

The nozzle 18 extends in a cylindrical occluder 20, the upper edge 23 of which is spirally cut. When the shells 12, 14 are joined, the occluder 20 extends within the outer shell 14 to occlude the vent 26 to a greater or lesser extent, depending on the location of the upper edge of the occluder 20, relative to the walls of the vent 26 which in turn depends on the degree of rotation of the shells 12, 14 with each other. When the subject blows through the bogille 18 and the outer shell 14, a portion of the expired flow of the subject will escape through the vent 26 and a portion will be directed through the tongue structure 16. When the shell is rotated inlet 12 with respect to the outlet shell 14, the spiral occluder 20 occludes the vent opening 26 in a greater or lesser proportion, thereby determining the extent to which the expired flow will be directed through the tongue structure 16. If enough flow is directed through the tongue structure 16, it will generate sound. The tongue structure 16 is non-linear (a linear whistle is one that will produce with reasonable accuracy double sound intensity to double the flow rate) and the duration, shape and mass of the tongue are chosen in such a way as to produce a sound inside. of the frequency range in which the human ear is most sensitive. The reed is adapted to produce sound with a pitch of approximately 1000 Hz. While the reed is non-linear, the device 10 can in this way be "linearized" by suitable design of the spiral occluder, More importantly, the tongue structure 16 provides a quick and clear sound initiation, when its flow threshold is exceeded. As an analog-to-digital device that is already "on" or "disconnected" with nothing intermediate, for this purpose, the tongue structure 16 is manufactured to exact tolerances in order to ensure minimum variation of unit in unit, such Each tab is activated at the same flow threshold.This eliminates the need to calibrate each verification device 10. In addition, the tab is configured to ensure that the thresholds for static flow and dynamics of the tongue extension 16 are close to each other. To minimize erroneous sound generation due to large fluctuations in the flow, this may waken during explosive flow in opposition to expiratory flow uni form through the device 10. With particular referensia to Figure 4, the tongue structure 16 is pressed into the housing 22 extending down to the inside of the outlet shell 14, the outer shape of the tongue structure 16 and the shape inside the housing 22 is in addition frustoconical. The inlet end of the tongue structure 16 is open to the inside of the inlet end of the housing 22 and the exit end of the tongue structure opens outward to the atmosphere within the horn-shaped mouth of the housing 22. The mouth in the form of a horn improves the audibility of the dispisitivo 10 as the output sona 14 that forms a resonanceia 46 around the housing 22. The entrance end of the housing 22 forms a transversely extending barrier 44. The barrier 44 shows a low-pass filter and helps to prevent the tongue in the tongue structure 16 from being astive by the subject using impulse or explosive flow rate tessans in order to obtain an excessively optimistic result in a test. The barrier 44 is constituted by a barrier plate formed at the inlet end of the horn-shaped outlet 22. As can be seen in Figure 5, the outer diameter of the barrier plate 44 is slightly smaller than the inside diameter of the barrier. outlet horn 22 at its inlet end to facilitate the passage of expiratory flow linked to the outlet horn 22. The inlet and outlet shells 12, 14 are formed with complementary coupling formations by which the two parts 12, 14 can hold together. One of these forming formations is integral are the barrier 44. On the side facing the nozzle 18, the barrier 44 is provided with a tubular spindle 72 which is dimensioned for rotating location within a subo 74 formed in the interior in the nozzle 18. The suble 74 is transported in three radially propelled arms 76. The spindle 72 is easily rotatable within the suble 74 and is retained in position by an outwardly extending flange 78 constituting a fastener shape. When the spindle 72 is in position in the suble 74, the flange is projected beyond the lip of the suble 74. The spindle 72 is divided into three sites to fasilitate its insertion in the suble 74. In order to avoid spindle retraction 72 of the subo 74 , a clamping lug 80 is pressed into the tubular interior of the spindle 72. The clamping lug 80 is dimensioned so as not to disturb the spindle 72, but simply to prevent the spindle 78 from being pushed back to the subo 74 without detrussing the monitor 10. In addition to the spindle 62 and subo 74, the deflection shapes include a strand directed into 54, formed at the end of the outer wall 24 of the outlet spout 14 and an outwardly directed slot 56 formed to extend peripherally to the outside of the tubular occluder 20. The strip 54 and the coupling end of the inlet shell 14 as well as the slot 56 and the oslusor 20, are dimensioned for the inlet and outlet shells 12, 14, to hold together with the strip 54 slidably engaging within the slot 56. The strip 54 and the slot 56 are finished smooth to ensure easy rotational movement of the constras body 12, 14. The edges of the ventilation opening 26 are limited by inwardly directed suppression walls 49 to the outer wall 24 of the outlet vessel 14. The suppression walls 49 extend to the resonance chamber 46 and they are dimensioned to slide sersanamente on the outer surface of the oslusor 20, in order to close the space between the occluder and the outer wall 24 of the resonance chamber of the outlet unit 46.

The base of the cylindrical wall of the occluder 20 is provided with multiple grooves 28 which are distributed uniformly with respect to the circumference of the occluder 20. The grooves 28 are part of the enslavement mesanism of the verification device 10 of the invention. The enslavement mesanism includes a shaveta 32 which is adapted for axial insertion into the grooves between the grooves 28. Shaveta 32 is integral is a shaveta carrier 34 which in use, is mounted on a guide 36 formed in the outlet shell 14. This interlocking mechanism is intended to enclave the bodies of body 12, 14, relative rotation. The ensuing mesanism is intended to be permanent, so that once enslaved on site, the enslavement can not be destroyed without destroying the monitor. At least, the ensuing mesanism must be difficult to "release". In the monitor 10 of the invention, the ensuing mesanism has been difficult to eliminate by the structure of the guide 36 and the key carrier 34. As can be seen from Figure 6, the guide 36 is limited by the formation of an external wall. 38 and includes a pair of parallel grooves 40, formed in the wall 24 of the chamber 46 on both sides of a central groove 42 formed in the wall 24 of the chamber 46. The key protractor 34 is illustrated in greater detail in the Figures 7, 8 and 9. In these drawings, the key protractor 34 can be seen to comprise a sliding plate 48 from the underside of which the key 32 and a pair of guide fasteners 50 depend. The guide fasteners 50 fasten in the slots 40 of the guide to retain the key carrier 34 within the guide 36, while the key 32 knows in the sentral slot 42 in the guide 36. By enslaving the input shaft 12 in the outlet shank 14 in a predetermined rotational position, the spiral occluder 20 is locked in a particular position with respect to the ventilation 26, in order to thereby determine the effective ventilation opening, as stated above, the ventilation opening is determined by the protosolo of treatment. The asanaladuras 28 allow the adjustment of the verification device 10 in small instruments. The ossusor 20 is provided as a stop shape 66 which is located to catch corresponding stops 68 at the maximum rotational positions of the entry point 12 relative to the output shaft. The stop formation 64 will butt against the stops 68 , either in the maximum "sawed" position or the maximum "open" position of the verifixing device 10. In the maximum "sawed" position, the upper surface 23 of the ossifier is closest to the upper extremity of the ventilation 26 according to Allow the rotation of the sonshas of body 12, 14. In the other rotasional extremity in the maximum "open" position, the upper surface 23 of the occluder is the most sersana to the lower extremity of the ventilator 26 as allowed by the rotation of the shells 12, 14. In use, the physician will determine the subject's diagnostic threshold with what will arm device 10 or instruct the subject how to assemble device 10 by engaging the inlet and outlet shells 10, 12 with each other, with the occluder 20 being in the position determined by the treatment protosolo of the subject. To assist in this assembly, appropriate markings 70 are effected in the nozzle 18. The appropriate marbles 70 are blown in accordance with the treatment protosolo. The marsas 70 take the form of flow rate values. It is required that the subject simply implements the verification regime at home - the subject will be told that the flow should be measured and the verification device will be used. The guide fasteners 50 include clamping formations 50.1, which retain the key carrier 34 within the guide 36, but the guide clamps 50 and the shaveta 32 thus are the grooves 40., 42 are dimensioned to allow relatively easy sliding of the shave carrier 34 within the guide 36. The sliding plate 48 of the key carrier 34 is formed with a V-shaped weakening line 58 on its underside, to provide a tongue. interlocking 48.1. The weakening line 58 allows easy bending of the clamping tongue 48.1 out of the plane of the guide plate 48. In this position, the bent clamping tongue 48.1 allows for easy assembling of the clamping mesanism, since it allows the location of the bearer shaveta 34 in the guide 36, are the shaveta 32 remotely located from the grooves 28 formed in the shank of the input body 12. The clamping tongue 48.1 of the guide plate 48 is provided with a latching pin which is downwardly dependent 59 The purpose of the pin 59 is to enslave the shaveta carrier 34 in position within the guide 36, after adjusting the rotational positions sorrestas of the sonshas of the body 12, 14.

This is done by sliding the shaveta holder 34 into the die of the mouthpiece 18. A flesha 60 is molded on the upper surface of the guide plate 48, in order to ascertain the desired sliding movement. Before the key carrier 34 slides in place as it was previously disengaged, the practitioner chooses the correct rotational adjustment of the body shells 12, 14 from each other, according to the predetermined treatment for the subject. With the correct rotational position selected, the key carrier 34 slides to the original position, such that the key 32 engages the appropriate slot between the grooves 28 formed in the occluder 20 in the inlet body shell 12. The facing ends of the grooves 28 are rounded and the leading end of the key 32 is tapered, both of which fasilize the entry of the shaveta 32 into the grooves between the grooves 28. With the key 32 in position between the grooves 28, the locking tongue 48.1 of the guide plate 48 can be bent back to the plane of the guide plate 48. In order to do this, the fastening pin 59 is forced into a shroud 64 formed in the guide 36.

The latching pin 59 is formed with an enlarged tang 59.1 which requires some force to allow entry of the tang into the plug 64. With the latching pin 59 in place in the plug 64, the latching tongue 48.1 of the latch plate 59 guide 48 is retained inside the guide walls 38. The space between the guide plate 48 and the guide walls 38 is made as small as possible. This ensures that it is difficult to obtain any support on the guide plate if an attempt is made to "release" the interlocking mechanism, for example when attempting to raise the locking tongue 48.1 against the locking of the locking pin 59 on the socket 64. If required, the device 10 can be predesigned for use by children or adults. In the above case, the size of the vent 26 may be predetermined to allow floors to flow up to 4501.min "1, while in the last space, the size of the vent 26 may be predetermined to allow floor flows of up to 8001. min "1. The device may suitably be salibrated for use by adults and alternately or in addition, one or more additional venting outlets (not shown) may be formed in the resonance chamber 46, preferably on its wall constituted by the horn-shaped outlet. .

It is noted that in relation to this date, the best method conosido by the solisitante to bring to the prststisa the sitada invention, is the sonvensional for the manufacture of the objects to which it refers.

Claims (7)

1. CLAIMS Having described the invention as above, the invention is drafted in the following terms: 1. A flow verifying device comprising a substantially hollow body formed with a passage for fluid flow incorporating a generator of signal, adapted to generate a signal that depends on the achievement of a fluid flow expense with predetermined volume through the signal generator, the body comprises first and second body shells, which are rotationally asoplatable with each other, to define a chamber of resonance formed within a vent outlet, the first sonar of the body formed is an inlet constituted by a nozzle and the passage for fluid flow extends at least between the nozzle and the vent outlet, the device includes an occluder that It adapts to occlude the ventilation outlet in a greater or lesser proportion depending on the rotational position of the shells of body relative to each other and the body shells include an interlocking mechanism by which the body shells can be locked together in increments to adjust the occluder to a predetermined incremental variation of the ventilation outlet size, characterized in that the locking mechanism comprises Multiple grooves formed in one of the body grooves and a key movably mounted in the other body member, the key being adapted for axial movement within the grooves between the grooves to lock the body parts together.
2. 2. A device for flow verification in accordance with claim 1, sarasterized because the resonance chamber is the output formed therein is defined substantially by the second sonar of the body and the ossulus is insorporated in the first body of the body and adapts to the Sonhas of the body are blown to extend into the resonance chamber, to occlude the ventilation outlet in a greater or lesser proporosion depending on the rotasional position of the body sonshas relative to each other.
3. 3. A device for flow verification in accordance with any of the preceding claims, characterized in that the body of the shaveta is formed is a guide and the shaveta is mounted on a shaveta carrier that is slidably mounted on the guide.
4. 4. A device for checking the flow of soundness is claim 3, which is sarasterized because the shaveta carrier includes a locking pin that is adapted for insertion and retention in a somplementary assembly apparatus that is formed in the bodywork.
5. 5. A device for verifying the flow of sound is any of the preceding claims, characterized in that the occluder which is silíndriso and adapted, suando the body shells are interengaged, to extend in the second body shell, the edge that extends Inwardly the occluder spirally forms and adapts to occlude the vent to a greater or lesser extent depending on the rotational position of the body shells relative to each other.
6. 6. A device for flow verification according to any of the preceding claims, characterized in that the body shells are interspersed by providing in one of the body stages an internal axial asanaladura and in another body of the body, an asanaladura assembly inside. The groove can be rotatably mounted on the sual.
7. 7. A device for verifying the flow of the sonformity is the claim 6, characterized in that the rod and the assembly are adapted for intercoupling in such a way that the axial detachment of the rod and the separate assembly of the verifisation device is prevented.