FIELD OF THE INVENTION

The invention relates to devices for diagnosing heart failure. More particularly, this invention relates to an accessory for a device that monitors pulsatile blood flow during a Valsalva Maneuver (VM).

BACKGROUND OF THE INVENTION

Heart failure-prone patients can be diagnosed by non-invasively monitoring the patients' physiological response, blood flow change, during administration of a Valsalva Maneuver (VM), i.e., a moderately forceful attempted exhalation against a closed airway. Heart failure-prone patients display characteristic signatures marked by minimal heart rate change, stable but elevated blood pressure, and an absence of momentarily and dramatically elevated post-VM recovery response.

Apparatus and method for performing VM are described in applicants' U.S. Publication No. 2015/0342468 by Semler et al., the description of which is incorporated herein by reference. In the aforesaid Publication, the patient's forced exhalation during VM is monitored by a mouthpiece electronically connected to a controller that also monitors and interprets the patient's cardiac response characteristics.

It has now been found, however, that a patient's moderately forceful attempted exhalation can be more uniformly and reliably achieved by a mouthpiece that requires a substantially constant continued exhalation pressure by the patient.

SUMMARY OF THE INVENTION

A whistling accessory for a Valsalva Maneuver (VM) device insures adequate forced exhalation during VM and includes a respiratory mouthpiece with an insert received into the mouthpiece. The accessory emits an audible sound when a patient blows into the mouthpiece at a predetermined level of effort.

The insert has a hollow, elongated main body portion which defines a primary resonance chamber and a hollow, conical connector portion unitary with the main body portion which defines a secondary resonance chamber in communication with the primary resonance chamber. The respiratory mouthpiece is mounted to the connector portion.

The elongated main body portion of the insert has a partially closed end which defines a central opening. The central opening provides communication between the primary resonance chamber and the secondary resonance chamber. The elongated main body portion also defines a sound aperture at the partially closed end and a unitary protruding wedge portion having a leading edge which extends into the sound aperture.

The hollow, conical connector portion is sized to be received into the respiratory mouthpiece, has an open distal end and a closed proximal end. A flared open channel is defined on an external surface of the conical connector the channel. The channel has a relatively smaller width at the proximal end of the connector portion and a relatively larger width at the distal end of the connector portion. The flared open channel extends from the proximal end of the connector to the distal end thereof and together with the respiratory mouthpiece defines an air passageway to the leading edge of the protruding wedge portion. The air passageway is sized to provide air flow back pressure (an exhalation pressure) of at least about 30 millimeters of mercury (mmHg), preferably about 30 mmHg to about 40 mmHg before an audible sound is produced while a patient undergoing a Valsalva Maneuver (VM) blows into the accessory.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIGURE l is a perspective view of a whistling accessory for a Valsalva Maneuver (VM) device embodying the present invention and having a respiratory mouthpiece with an insert for generating an audible sound;

FIGURE 2 is a sectional side elevation view taken along plane 2-2 of the whistling accessory shown in FIGURE 1 ;

FIGURE 3 is a perspective view of the insert shown in FIGURE 1;

FIGURE 4 is a side elevation view of the insert shown in FIGURE 3;

FIGURE 5 is a top view of the insert shown in FIGURE 1;

FIGURE 6 is a sectional side elevation view taken along plane 5-5 in FIGURE 3; FIGURE 7 is a front view of the insert shown in FIGURE 3;

FIGURE 8 is a rear view of the insert shown in FIGURE 3;

FIGURE 9 is a perspective view of another whistling accessory that embodies the invention; and

FIGURE 10 shows the whistling accessory of FIGURE 9 further provided with a filter in a transparent housing downstream from the mouthpiece.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The terms "proximal" and "distal" as used herein and in the appended claims are used with reference to a patient preforming a Valsalva Maneuver (VM) using the whistling accessory. The term "proximal" refers to a portion of the whistling mouthpiece closest to the patient and the term "distal" refers to the portion thereof further away from the patient.

Referring to FIGURES 1 and 2 of the drawings, whistling accessory 10 has respiratory mouthpiece 12 mounted to insert 14 which has a hollow, elongated main body portion 16 and a hollow conical connector portion 18 unitary therewith.

As shown in FIGURE 2, main body portion 16 has a partially closed end 20, an end 22 opposite the partially closed end 20, and defines a primary resonance chamber 26. The conical connector portion 18 is unitary with body portion 16 and defines secondary resonance chamber 28 with open distal end 34 and closed proximal end 38. Central opening 34 at partially closed end 20 of main body portion 16 provides a communication path between primary resonance chamber 26 and secondary resonance chamber 28. End 22 can be open or closed. An open end 22 is preferred, however.

The relative volumes of primary resonance chamber 26 and secondary resonance chamber 28 can vary; however, the volume of the primary resonance chamber is larger than the volume of the secondary resonance chamber. Preferably, the volume ratio of the primary resonance chamber to the secondary resonance chamber is in the range of about 6 to about 9, more preferably about 7 to about 8. Total chamber volume usually is in the range of about 0.9 cubic inches to about 0.2 cubic inches. Conical connector portion 18 defines flared open channel 40 (FIGURES 2, 3, & 4) which, together with mouthpiece 12, in turn defines air passageway 42 which begins at closed proximal end 38 of connector portion 18 and terminates at open distal end 36.

Main body portion 16 also defines sound aperture 24 at partially closed end 20 and has a protruding wedge portion 30 with an arcuate, relatively narrow leading edge 32 that extends into sound aperture 24, faces channel 40 and air passageway 42, and top edge portion of leading edge 32 is aligned with middle of channel 40 and air passageway 42, and presents a minimally flat surface substantially perpendicular to air flow that exits air passageway 42.

An upper portion of leading edge 32 can be chamfered (beveled), if desired. A preferred chamfer has a face width in the range of about 0.1 mm to about 0.5 mm, more preferably about 0.25 mm, at an angle of about 45 degrees.

A preferred fillet is a convex fillet having a radius in the range of about 0.1 to about 0.5 mm, more preferably about 0.25 mm.

The distal or trailing bottom edge of channel 40 likewise can be chamfered or filleted, if desired, the chamfer or fillet having the same preferred dimensions as stated hereinabove.

FIGURES 5 and 6 illustrate a preferred contour for flared open channel 40 defined by the conical surface of conical connector portion 18 and juxtaposed to arcuate leading edge 32. Preferably, channel 40 has a substantially uniform depth of less than one millimeter. Channel 40 together with the mouthpiece define air passageway 42 with a square edged orifice which requires an air flow back pressure of at least 30 mm Hg to generate audible sound. For a square edged orifice of about 0.7 mm by 0.7 mm a total resonance chamber volume preferably is about 0.3 cubic inches. At the distal end, channel 40 preferably has a uniform depth of less than one mm and a width in the range of about 3 mm to about 5 mm. More preferred dimensions for channel 40 and air passageway 42 at distal end 38 that together with mouthpiece 12 define the square edged air input orifice 41 (FIGURE 7) at the proximal end 38 are less than one millimeter (mm) by one millimeter (mm), more preferably about 0.7 mm by about 0.7 mm, and at the distal end are about 0.7 mm by 3.8 mm. Dimensions of the conical connector portion preferably conform to the International Standard ISO 5356-1. Preferred are the 15 mm and 22 mm cone sizes used for breathing systems. A 15 mm connector portion preferably has a taper length of at least 16 mm and a taper ratio of 1 :40. A 22 mm connector portion has a taper length of at least 22 mm and a taper ratio of 1 :40.

FIGURE 7 shows proximal end view of insert 14 and FIGURE 8 shows distal end view of insert 14.

Whistling accessory 50 shown in FIGURE 9 has an insert 54 with the same internal arrangement of parts as insert 14 shown in FIGURES 1-8 and described hereinabove. Insert 54 also has a dorsal rib or fin 55 which discourages a user from inadvertently blocking the sound aperture of the insert. Respiratory mouthpiece 52 is mounted to the conical connection portion of insert 54.

FIGURE 10 shows whistling accessory 60 with insert 54 and having an optional filter 72 which is operably associated with respiratory mouthpiece 62 and situated in a transparent housing 70 downstream from the proximal end portion of the mouthpiece. Transparent housing 70 is mounted to connector portion 58 of insert 54. Transparent housing 70 can be unitary with mouthpiece 62 or a separate unit mounted between mouthpiece 62 and connector portion 58.

While performing a VM, a patient blows into the respiratory mouthpiece with sufficient effort to generate an audible signal, usually having a frequency of about 2,000 Hertz (Hz), for at least 10 seconds during which time period the patient’s cardiac function is monitored, usually by means of a sensor measuring blood volume changes in an upper extremity. The sensor detects changes in arterial blood volume and provides a digitized signal that is analyzed utilizing specifically designed software.

The foregoing description and the drawings are illustrative and are not to be taken as limiting. Still other variants and arrangement of structural elements within the spirit and scope of this invention are possible and will readily present themselves to those skilled in the art.