2. Prior Art There are known in the art many devices for human respiratory exercise or for the practice of breath control. Devices of this type are exemplified in U.S.

Patent No. 4,499,905 to Greenberg et al., U.S. Patent No.

3,811,671 to Turnbull, U.S. Patent No. 4,086,918 to Russo, and U.S. Patent No. 3,695,608 to Hanson. Such devices typically involve the exhalation of air into, or inhalation of air from, an enclosed chamber.

Also known are instruments for the purpose of measuring the amount of air entering or leaving human lungs. Such instruments are sometimes referred to as spirometers. Particular examples are disclosed in U.S.

Patent No. 4,499,905 to Greenberg et al., U.S. Patent No.

3,722,506 to McMillan and U.S. Patent No. 3,826,247 to Ruskin et al.

Many spirometer devices are costly and cumbersome.

Although newer, more portable instruments are now available, there remains a need for volumetric spirometers which can be more conveniently packaged for transport and more convenient for the user to operate.

The spirometer device disclosed by Greenberg et al.

in U.S. Patent No. 4,499,905 is described as a portable spirometer which is accurate and reliable, yet relatively inexpensive and easily transportable. The Greenberg et al. spirometer includes a breathing tube which is formed with a series of corrugations along the length thereof.

The corrugations prevent the breathing tube from accidentally kinking during use. The tube may be made of a polyethylene or a ethylene vinyl acetate. The Greenberg breathing tube, although flexible, cannot hold itself in a particular configuration desired by the user. Also, the Greenberg tube cannot be conveniently packaged with the device since it cannot be reduced in its overall length for packaging. There remains therefore a need in the art for an improved breathing tube which is conveniently packageable with the spirometer for shipment thereof, while at the same time, is much more user friendly than prior art tubes, allowing the user to chose the length and configuration thereof during operation.

OBJECTS AND SUMMARY OF THE INVENTION It is a primary object of the present invention to provide a device for measuring the amount of air inhaled

by human lungs.

It is another object of the present invention to provide for the measuring or testing of human breathing capacity by means of a device which is accurate, reliable, readily portable, conveniently packageable, and simple and convenient for the user to operate.

A further object of the present invention is to provide an inhalation device that includes a breathing tube which can be reduced in length for packaging, and thereafter conveniently extended and configured by the user during use.

A further object of the invention is to provide an inhalation device which will indicate both the volume of inhaled air and the rate of inhalation.

Briefly described, the presently preferred embodiment of the invention includes a spirometer having a first and second chamber.

The first hollow cylindrical chamber includes a piston which is suitably positioned and adapted to be movable therein. The chamber is vented to atmosphere.

The second hollow chamber includes a counterweight position therein and is also vented to atmosphere. The two chambers are integrally formed with a base and a handle as a single integral unit preferably formed of a polymeric material.

An inhalation tube assembly includes a flow passage way which is in air flow communication with both the first and second chamber and which is integrally formed

therewith. The flow passage way forms a connector that can mate with a breathing tube which completes the assembly and the flow passage way. The remote end of the breathing tube may be formed into a mouth piece through which a patient can inhale to cause the piston and the counter weight to move.

The relationship between the inhalation tube assembly and the first and second chambers is such that a major portion of the inhaled air comes from the atmosphere through the second chamber and a minor portion from the first chamber in a predetermined manner so that a large volume of air can be inhaled with a relatively compact device. The first chamber piston assembly indicates the volume of air inhaled by its position within the chamber.

Because the piston has weight and friction, it slows down the air flow from the first chamber. To compensate for this resistance, the counter weight in the second chamber operates to provide an equivalent or nearly an equivalent amount of drag to the air flow through the breathing tube assembly. The counter weight is constructed and arranged to take into account the effect of the frictional drag forces on the amount of air being inhaled. Movement of the counter weight during inhalation also effectively indicates the flow rate of air through the device.

The preferred embodiment of the breathing tube of the present invention is formed of an elongated section of corrugated polymeric material which allows the tube to be collapsed to a shortened length which is approximately

equivalent to the height of the spirometer, but may be extended to a length up to five times its completely collapsed length. Also, the corrugations used to collapse the tube will allow the tube to be bent or positioned in any desired configuration. The tube will remain in the configuration until changed by the user. In this manner, the user may adjust the tube to a specific length which allows optimal viewing of the volume and flow displacement elements of the spirometer, while at the same time allows the tube to be easily placed in the user's mouth.

While in its completely collapsed configuration, the tube may be positioned for packaging with the spirometer directly adjacent the spirometer's handle in a stream line manner which simplifies packaging of the device for shipment. Further, the fully collapsed configuration of the tube allows for conveyor type automation of the packaging process, potentially reducing manufacturing costs and simplifying the packaging of the device by a user for easy storage thereof if desired.

The above and other aspects and advantages of the present invention will be more completely understood by the following detailed description of the preferred embodiment thereof. The accompanying drawings which are incorporated in and constitute part of the present specification also illustrate a preferred embodiment of the present invention, and together with the detailed description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a spirometer made in accordance with the principles of the present invention; Figure 2 is a front view of a spirometer and fully collapsed breathing tube positioned thereon for packaging as contemplated in the preferred embodiment of the present invention; and Figure 3 is a perspective view of the spirometer with the preferred embodiment of the breathing tube attached thereto for use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 shows a preferred embodiment of a spirometer 10 of the present invention without the breathing tube in place thereon. The spirometer 10 includes a base 12 on which the inhalation structure is mounted. The base 12, in addition to serving as a base, can also function as a stand to maintain the inhalation structure in an upright position. The base 12 holds a first cylindrical chamber 14 and second cylindrical chamber 16 in a vertical upright position. The first and second chambers 14 and 16 respectively are integrally formed as part of a frame 18 which also forms a handle 20 and the breathing tube connector 22. The interior of the first cylindrical chamber 14 is at least in part preferably frosted to reduce the surface area and to reduce resistance for movement of a piston 24 therein. The first and second

cylindrical chambers 14 and 16 respectively are in fluid communication with the breathing tube connector 22 by virtue of a pair of air flow passage ways (not shown).

The first cylindrical chamber 14 is open to the atmosphere by virtue of a series of apertures 26.

The second cylindrical chamber 16 includes a counter weight 28 and is also open to the atmosphere by virtue of a series of apertures 30.

The first and second cylindrical chambers 14 and 16 are designed so that in use, a relatively large portion of the inhalation air of a patient comes from the atmosphere and passes through the spirometer 10 and only a relatively small portion of the inhalation comes directly from within the spirometer 10. This is significant in that it permits the inhalation of a relatively large volume of air even though the spirometer 10 itself is relatively compact in size.

In one embodiment of the spirometer 10 of the invention, approximately 2,500 ml of air can be inspired with a spirometer 10 which has an interior volume in its first cylindrical chamber 14 of only 5% to 10% of that total amount. An example of a spirometer 10 used in accordance with the principles of the present invention is presently manufactured and sold by Sherwood Medical Company under the trademark Voldyne 2500. A detailed explanation of the mechanics of the flow of inspired air through the spirometer 10 of the present invention is presented and described in U.S. Patent No. 4,499,905

issued to Greenberg et al. which is incorporated herein by reference in its entirety.

Briefly, as explained in the above referenced and incorporated patent, the piston 24 moves upwardly upon inhalation to a position corresponding to the total volume of inspired air as indicated by the indicia 32.

Simultaneously, the counter weight 28 moves upwardly based on the rate of air flow through the second cylindrical chamber 16 and gives an indication of the air flow rate to the user by means of the indicia 34. Air inspired from the first and second cylindrical chambers 14 and 16 into the breathing tube 36 must pass through a pair of air flow passageways (not shown) as noted previously. These air flow passageways are sized such that the passageway leading to the atmosphere through the second cylindrical chamber 16 is considerably greater than the size of the passageway leading to the first cylindrical chamber 14 in which the piston 24 is located. The ratio of the size of the pair of air flow passageways can vary depending on the circumstances from 4:1 to 15:1. This ratio of the size of the pair of air passageways controls the ratio of air being withdrawn from the first cylindrical chamber 14 with respect to the amount of air being drawn from the atmosphere through the second cylindrical chamber 16.

Thus, the relative size of the pair of air passageways determines the amount of air drawn from the first cylindrical chamber 16, which in turn is a fixed ratio of the total amount of inspired air. The amount of air

withdrawn from the first cylindrical chamber 14 determines the amount of movement of the piston 24 therein, which in turn therefor determines the proper position of the indicia markings 32 thereon.

As noted heretofore, the counter weight 28 provides resistance in the second cylindrical chamber 16 to balance the resistance in the first cylindrical chamber 14 caused by resistance to movement encountered by the piston 24.

The counter weight 28 therefore maintains the accuracy of the position of the piston 24 throughout the entire indicated range, regardless of flow rate changes.

Referring now to Figure 2, the spirometer 10 is shown in conjunction with the breathing tube 36. In Figure 2, the breathing tube 36 is shown in its fully collapsed configuration and positioned on the spirometer 10 in the opening 38 between the handle 20 and the first cylindrical chamber 14. This is the preferred position for packaging and transporting the packaged device prior to use, and for repackaging the device for storage in between uses if desired. The opening 38 is sized to accommodate the rough diameter and minimize length of breathing tube 36 so as to minimize the total overall dimensions of the spirometer 10 and breathing tube 36 when oriented in the manner as shown in Figure 2 for packaging or storage.

The breathing tube 36 is formed with a mouthpiece 40 at one end thereof which may be formed separately from the tube and subsequently attached, or which may be formed integrally therewith, and a connector 42 at the opposite

end thereof. The connector 42 is sized to fit over the breathing tube connector 22 of the spirometer 10 in an airtight friction fit. The mouthpiece 40 is sized to easily fit within the mouth of the user and be gripped by the user's teeth during breathing exercises. The mouthpiece is shaped to allow the user's mouth to easily seal there around to ensure that all inspired air passes through the tube 36.

Referring now to Figure 3, the breathing tube 36 of the present invention is used by removing it from its storage position on the spirometer 10 and attaching the connector 42 thereof to the breathing tube connector 22.

The central section 44 of the tube 36 is formed of many short bends or ripples which are evenly spaced along the tube in accordion fashion and which allow the tube to be collapsed or expanded. Each bend or corrugation includes a corrugation peak and a corrugation valley. The diameter of the tube 36 changes approximately one quarter of an inch between each corrugation peak and valley in the preferred embodiment of the tube 36. Also, the preferred embodiment of the tube 36 has an internal diameter at the corrugation valleys thereof of approximately seven-eighths of an inch and at the corrugation peaks thereof of approximately one and an eighth inches. The length of the tube 36 in its fully expanded configuration is preferably 18 inches and a fully retracted length of approximately six inches.

During manufacture and packaging of the spirometer 10 of the present invention, the tube 36 is reduced to its completely collapsed configuration and placed in the opening 38 formed by the handle 20 of the spirometer 10.

The tube 36 may be placed in this position during the manufacturing and packaging of the device by an automated procedure. For example, a large number of tubes 36, in their fully collapsed and straight configuration, can be loaded into a hopper which will orient them all in a uniform direction and load them to a conveyor belt or to a robotic arm which in turn can drop each tube 36 in place in the opening 38 of a spirometer 10 as each spirometer 10 is indexed into position for receiving a tube 36. The combined tube 36 and base 12 can then be immediately packaged in such a manner as to retain the relative position of the tube 36 in the opening 38. Alternatively, the tube may be retained in the opening 38 by means of an intermediate retention device, such as adhesive tape, and then subsequently the combined breathing tube 36 and base 12 can be packaged.

In operation, the user removes the tube 36 from the opening 38 and attaches the connector 42 thereof over the breathing tube connector 22. Next, the user extends the tube 36 to a desired length, and bends the tube 36 to the desired configuration for use (see Figure 3). In this manner, the user may adjust the tube 36 to a specific length which allows optimal viewing of the volume and flow displacement of the spirometer 10, while at the same time

shaping the tube 36 in a configuration which allows easy placement of the mouthpiece 40 thereof into the user's mouth. Once the tube has been configured by the user, it will maintain its configuration without the need for the user to hold the tube during use.

The user then places the mouthpiece in the mouth and inhales. The removal of air from the first cylindrical chamber 14 causes the piston 24 to rise. The height of the piston 24 can be recorded by positioning the height indicator 46 at the highest point of the piston 24 against the indicia 32.

The air inhalation also causes the counter weight 28 to rise in the second cylindrical chamber 16 to give a measure against indicia 34 thereon of the rate of air flow.

When inhalation stops, the piston 24 will slowly return to the bottom of the first cylindrical chamber 14 and the counter weight 28 rapidly drops back to the bottom of the second cylindrical chamber 16.

It is to be understood that the above described embodiment is only illustrative of the application of the principles of the present invention. Numerous modifications or alternative arrangements or embodiments may be devised by those skilled in the art without departing from the spirit and scope of the present invention.