IL41349A - A breathing device through which an individual can repeat both the inhaling and exhaling phases of respiration and method for increasing ventilation and active dilation of the lungs using the device - Google Patents

Description

ns*v3ni na»wn »a">^ >y ιι τη> O TR ισβκηο ι »τι ηβ»&3 |ρηη η Μ'ί '{ nimn, naiuww nn»*n main* πο«σι A BREATINff DEVICE THROUGH WHICH AN INDIVIDUAL CAN REPEAT BOTH THE INHALING AND EXHALING PHASES OP RESPIRATION AND METHOD FOR INCREASING VENTILATION AND ACTIVE DILATION OP THE LUNGS A strac o the Disclos re · A breathing device for* use by a postoperative patient to prevent pneumonia comprises: a closed elongated tube having a volume of about 800 cc to about 1,500 cc, a mouthpiece at one end of the tube ; air openings at the ^>ther end of the tube for admitting air when air is inhaled from the tube and for expelling air when air is exhaled into the tube; a valve associate • with the aix* openings and adapted to admit air readily into the t when air is inhaled therefrom but to restrict the flow of exhale air out of the tube. The tube can be provided with a second valve which prevents exhaled air from being expelled from the tube until after the pressure of the exhaled air in the tube has built up to an amount 'substantially greater than atmospheric pressure. .

Field of the Invention This invention relates to a 'breathing device for use by a postoperative patient for the purpose of preventing the development p pneumonia in the patient.

It is known that a postoperative patient who suffers pain when breathing as a result of the operational wound has a tendency to take shallow breaths to alleviate such pain.. The lungs of an individual who takes shallow breaths are ot expanded fully. When the lungs are not expanded fully, there tions of the lungs (partial collapse of the lungs). This can lead to poor gas exchange and nay result also in pneumonia.

Reported Developments It is known that the development of atelectasis in a postoperative patient can be prevented by encouraging the postoperative patient to take deep breaths or by encouraging the patient to exhale against a pressure greater than atmospheric pressure.

Various devices have been developed for this purpose.

One such "device consists of an open-ended elongated tube that has a mouthpiece through which the patient inhales and exhales air. The volume of ai in the open-ended tube increases the patient's "dead space", that is, the space between the gas-exchange portion of the lungs and. the atmo.sphere. The increase in dead space encourages the patient to take deeper breaths because of the accumulation of carbon dioxide in the dead space. However, a patient utilizing this device expires at approximately atmospheric pressure, and thus, he does not benefit from the expiratory phase of respiration.

A "blow bottle" is a device that is used for the purpose of encouraging a postoperative patient to exhale with a relatively large force. This device consists of a bottle partially filled with water and a tube, one end of which is below the water level of the bottle. The patient, after taking a breath, exhales into the tube and the exhaled air exits from the tube through the end thereof which is below the water level of the bottle. The air which is expeiled into the bottle is allowed to escape through an opening in the bottle wh ch is above the water level of the bottle. A patient using this device must expire with a force which exceeds the pressu e barrier of the water. However, it should be noted that the patient's inspiratory phase of respiration is not benefitted by the use of this device.

Another device which performs the same function as the above-described blow bottle, but which, it is believed, has never been used medically, is disclosed in U. S. Patent No. 652,987. This device resembles a cigar and consists of a tube having a mouthpiece at one end through which the patient inhales and exhales and perforations at the other end through which air is admitted into the tube. Upon expiring into the tube, the perforations are clor.ed-off by a valve and the expir air escapes from the tube through apertures of .a smaller size than the perforations. Thus, the individual is encouraged to §κ¾δΙ§ yit § greater ihan &l feree i@ eapsl the g¼hal@g air from the tube.

A disadvantage of the blow bottle and the device described in the aforementioned patent is that they are incapable of encouraging the patient to breathe in deeply. Another disadvantage of the blow bottle is that it is relatively cumbersome to use.

Another device used in this field is an intermittent positive pressure breathing apparatus. This device uses com-pressed air as a source of energy. By appropriate triggering of valves at the start of inhalation, air at a predetermined increased pressure is forced through a mouthpiece. The flow o air is terminated when a predetermined pressure is reached at the mouthpiece. Thus, exhalation is passive and unaffected by the use of this device. Other disadvantages of this device are that it is relatively costly to purchase and also to use because it requires the attention of an operator. This results in the devices not being readily available to the patient. In practice , the patient rarely receives treatment more than once every 3 hours. Furthermore, in using the device, care must be exercised to avoid the forcing of air into the patient's stomach. If this occurs, not only is the patient made uncomfortable, but also it is more difficult for the patient to expand his lungs both during the treatment and for several hours after treatment. Also, since the device is used by many patients, care must be exercised to prevent the spread of infectuous disease. In addition, care must be exercised in the use of the machine to prevent pneumophorax (blow-out of the lungs) .

In view of the above, it is.an object of this in-vention to provide improved means for promoting better aeration of the lungs .

It is another object of this invention to provide improved means for preventing the development of pneumonia in a postoperative patient.

Brief Description of the Invention In accordance with this invention, there is provided a breathing device for use by a postoperative patient which encourages the patient to take deep breaths and to exhale against a pressure substantially greater than atmospheric pressure. The breathing device comprises a closed container having a volume of at least about 500 cc for receiving and holding air, passageway means, preferably inhaled fron the container and exhaled into the container by, the patient, air passage means through which air is admitted into the container when the patient inhales through the mouthpiece and through which air is expelled from the container when the patient exhales through the mouthpiece into the container and means for increasing the exhalation force needed to expel air from the container relative to the exhalation force needed to exhale air directly into the atmosphere.

In its preferred form, the breathing device comprises a closed elongated tube having a volume within the range of about . 800 cc -to about 1,.500 cc, a mouthpiece at one end of the tube having an opening into the tube, the other end of the tube having air passage means for admitting air into the tube when air is inhaled therefrom by the patient through said mouthpiece and through which air is expelled from the tube when the patient exhales through the mouthpiece into the tube, a valve associated with the air passage means and adapted to admit air into the tube when air is inhaled therefrom through the mouthpiece and to restrict the flow of air when air is exhaled through the mouthpiece into the tube. . .

As will be explained more fully below, the breathing device can include also design features which prevent exhaled air in theJ tube from being expelled therefrom until after the pressure of the exhaled air in /the tube is substantially greater than atmospheric pressure.

The breathing device of this invention has a number of advantages over heretofore available devices which have been used in efforts to prevent the development of atelectasis or pneumonia in postoperative p tients. The breathing device is capable of functioning in a manner such that it encourages the postoperative patient to both breathe deeply and expire with a greater than normal force. Heretofore available breathing dsvicae do net BO funetion. In addition* the b eathing device of this invention is relatively simple in structure, requires little or no maintenance and can be constructed from relatively inexpensive materials and assembled easily. Because the device is simple to use, a patient can be instructed how to use it in a very short time. In its preferred use as a disposable item, the risk of spreading an infectuous disease such as tuberculosis, is minimal.

Brie Description of the Drawings Figure 1 is a perspective view of a breathing device in accordance with the invention.

Figure 2 is an enlarged broken-out longitudinal sectional view of the breathing device as taken on the line 2-2 of Figure 3, and shows the valve of the device in its closed position.

" Figure 3 is a cross-sectional view taken on the line 3-3 of Figure 2.

Figure t is a longitudinal sectional view similar to Figure 2, but taken on the line H-U of Figure 5 and shows the valve of the breathing device in its open position.

Figure 5 is a cross-sectional view taken on the line 5-5 of Figure M with the valve shown in its open position in dot and dash lines. - Figure 6 shows a modification that can be made to the breathing device shown in Figures 1-5.

Detailed Description of the Invention A preferred form of the breathing device of this invention is shown in Figures 1 to 5 of the drawing. The device comprises an elongated tube 2 having a circular cross section of constant diameter for receiving and holding air. The tube is composed preferably of a material which is substantially inflexible, that is a material which will not distort under the pressure or force created by an individual inhaling air from and exhaling air into the tube. Cardboard and relatively rigid plastics are examples of suitable materials which can be used.

One end of the tube 2 is closed with an end cap 4 which snuggly fits the tube. The end cap 4, which can be made of metal, has an opening 6 into which there is fitted tightly a tube 8 of smaller diameter than the tube 2 and through which air can be inhaled from the tube 2 and exhaled into the tube 2 by the individual. To accomplish this, the individual can place the tube 8 between his lips and breathe in and out through it. To reduce or avoid the passage of air between the lips directly from or into the atmosphere, the tube 8 can be fitted with an appropriate mouthpiece. Similarly, to reduce or avoid the passage of air through the nostrils directly into or from the atmosphere, the tube 8 can be fitted with an appropriate face-mask which forms an airtight seal over the nose and mouth.

Also, a noseclip can- be used when breathing through the device. In addition, the tube 8 can be connected to a tracheotomy tube or an endotracheal tube when the condition of the individual makes this appropriate. The tube 8 can be made of any suitable material such as, for example, flexible polyethylene or other suitable plastic.

The other end of the tube 2 is closed also with an end cap 10 having openings 12, 14, in^ and*^14//. The inside surface of the end cap 10, which fits the ^ube snuggly and can thin sheet of polyethylene or other suitable material, is associated with the openings 14, 14^ and 14^/ and functions as a valve which allows air to be admitted into the tube 2 through said openings , but prevents air from being expelled from the tube through said openings as will be explained more fully below. Thus, air can be expelled from the tube 2 only through opening 12 which is a relatively small hole creating a large pressure differential at high flow rates.

For the purpose of illustration, there are set forth below exemplary dimensions of a breathing device of the type shown in Figures 1-5 : length of tube 2 (filled kraft) inside diameter of tube 2 thickness of wall of tube 2 volume of tube length of tube 8 (polyethylene tube) inside diameter of tube 8 thickness of tube 8 diameter of opening 12 diameter of openings 14, 14^ 8 14^ flap 16 3/4" x 1" polyethylene film having a thickness of 1.5 mils.

In utilizing the breathing device, the patient inserts a mouthpiece, preferably fitted on the end of tube 8, inside his lips and partially into the mouth. Upon inhaling through the mouthpiece , the patient draws air from the tube into the lungs. Upon such inhalation, air enters the tube through the air passages provided by the openings 12, 14, 14^ and 14//. (See Figure 4.) It should be appreciated that upon inhalation, there is created in the tube a slight vacuum, the force of which lifts the flap 16 away from the air passage openings 14 14^ and 14^ thereb ermittin air to enter the tube through said openings. After inhaling and while maintaining the mouthpiece between the lips, the patient exhales therethrough into the tube 2. The exhaled air is expelled from the tube through the unrestricted, but small opening 12. On the other hand, the openings 14, 14 ^ and 1 ^ are not available fcr the expulsion of air from the tube because the flap 16 , in the absence of the vacuum created by inhalation and under the pressure of the exhaled air, returns to its normal position in which it covers the air passage openings 14 , 14^ and 1 ^/ . By restricting the flow of air which is expelled from the tube , the patient is forced to exhale against a pressure substantially greater than atmospheric pressure. This increases his force of exhalation and the intra-alveolar pressure which results in more complete dilation of the distal alveoli thereby preventing or even reversing partial collapse of the lungs.

As mentioned hereinabove , the breathing device of this invention functions also to increase the depth of respiration as a result of increased dead space. The volume of the breathing device is critical for accomplishing this. The volume must be large enough to accommodate a sufficient amount of exhaled air, which is carbon dioxide rich, so that when the patient inhales the carbon dioxide-rich air from the device , his system will 1 immediately sense this. Through reflex action, the patient will breathe more deeply in an effort to blow-off or dilute the relatively high levels of carbon dioxide. It should be appreciated that if the volume of the breathing device is not sufficiently large , the patient will not be encouraged to take deep breaths because upon inhalation, he will not be elevating the partial pressure of carbon dioxide in his lungs and blood. It should be appreciated also that the positional relationship of the means through which air is inhaled from and exhaled into the tube 2 or more) which is inhaled by the patient prior to his -inhaling fresh air which enters the tube 2 during inhalation. ihe appropriate volume of the device will tend to vary because of the difference of respiratory parameters of different sized individuals. For example, the volume""of the lungs and air passage ways of an average 150 lb. male is about 6^000 cc i the dead space of such an individual is about 150 pc and the volume of his normal breaths is about 500 cc. Therefore, with each breath he ventilates the gas exchange portion of his lungs with about 350 cc of air. It should be noted that about 2,000 cc of gas remains in the lungs at the end of a normal expiration Thus, the individual has about 2,500 cc of gas in his lungs at the end of inspiration, much less than the 6,000 cc that his lungs will accommodate. A function of the breathing device of the present invention is to cause the patient to increase significantly the amount of air in his lungs at the end of inspiration. It is a fair approximat on to say that when the patient's dead space is increased by about 500 cc, the volume of his normal breath will be increased from about 500 to about 1,000 cc. He therefore will have about 3,000 cc of air in his lungs at the end of inspiration. Thus, by increasing the . dead space by 500 cc, the patient increases the amount of air in his lungs by 20%. A greater increase would be more helpful. However, it should be appreciated that the above parameters can be somewhat smalle -for smaller sized individuals, and thex^e fore, the 500 cc volume can be somewhat smaller also. However, in general, the minimum volume should be in the range of about 500 cc.

- In general, the volume of the breathing device should range of about 3,500 cc.

In its preferred form, the breathing device should provide for substantially laminar flow of air into the lungs. The reason for this is the increased dead space provided by the device will function most effectively if there is minimum mixing of trapped The device, shown in Figures 1-5 provides for substantially laminar flow of air into the lungs as a result of the relationship of the openings through which air enters the device from the atmosphere and the mouthpiece through which air is inhaled from the device and as a result of the device being void of any material which would cause turbulance of the air flowing therethrough .

Considering a complete breathing cycle to be an inhalation of air from the breathing device and an exhalation of air into the device, the number of cycles for which the patient should use the device will depend on how rapidly carbon dioxide builds-up in the blood, as well as how badly the lungs need the increased expansion. About 1/2 to about 6 consecutive minutes utilizing the device and repeating this every .30 to 60 minutes are exemplary conditions of use. As the device is used it is believed that a new respiratory equilibrium with higher levels of alveolar CO2 is attained and the increased partial pressure of the CO2 in the blood continues to trigger the reflex action which causes the patient to breathe in more deeply. It should be noted that the slightly reduced levels of oxygen , in the inspired air, as well as, possibly the increased expiratory pressure will accentuate the effects of elevated carbon dioxide in the alveoli.

A modification of the device which can result in increased effectiveness is shown in Figure 6, which is a view similar to the left hand portion of Figure 2. The modification includes a design feature which will result in a build-up of expiratory pressure in the device before air escapes therefrom.

With reference to Figure 6 , the outside surf ce of the endcap 11 is provided with the threshold flap 19 which covers the opening 13. During inhalation, air is admitted into the tube 3 through the openings 15 , 15^ and 15^ as the flap 17 is opened by the vacuum in the tube 3 created by the force of inhalation; during inhalation, threshold flap 19 covers the opening 13. Upon exhalation, the flap 17 covers the openings 15, 15^ and 15^ and the threshold flap 19 remains in its closed position covering opening 13 until sufficient pressure has built-up in the tube 3 from the exhaled air to cause the threshold flap 19 to release and allow air to be expelled from the tube to the atmosphere. Thus, threshold flap 19 is mounted to provide a resistive force which must be overcome by the patient's exhalation force before air ;will be expelled through the opening 13. The threshold flap 19, which functions as a valve, can be made of any suitable material such as for example, flexible or spring steel, which can be attached to the endcap 11, for example, by epoxy glue.

The threshold flap 19 should not open until the pressure of the exhaled air in the tube 3 is substantially greater than atmospheric pressure. The greater the pressure of the exhaled air in the tube 3 , the better the aeration of the lungs as the patient exhales against the pressure. Significant improvements in aeration can be realized when the pressure in the tube is at least about 5 cm of water above atmospheric pressure. ; Thus, the flap 19 should remain closed until the pressure in the tube at least about 5 cm of water above atmospheric pressure by the patient's exhalation. The patient is prevented from expelling air through the tube by the closing of the flap. This occurs when the pressure in the tube falls below the value that is required to maintain the flap in its open ρθθ&ΐΐοη.

The patient should not be required to exhale against a pressure which makes expiration too difficult or uncomfortable. Such pressure can tend to vary from patient to patient. Generally speaking, it is recommended that the patient not be required to exhale against a pressure greater than about 40 cm of water above atmospheric pressure. Significantly increased aeration of the lungs and comfortable expiration can be realized by providing a flap 19 which opens when the pressure in the tube 3 is within the preferred range of about 8 to about 20 cm of water above atmospheric pressure.

The modification shown in Figure 6 results in increased effectiveness respecting alveolar dilation and, with proper choice of pop-open pressure, peak instantaneous effect, be-cause high intra-alveolar pressures will be attained with the largest amount of air in the lungs. It should be appreciated that the use of the device shown in Figure 6 results in the patient's expiring throughout expiration, including at the end of expiration, against a pressure greater than atmospheric i pressure. This functions to increase the functional residual capacity of air in the lungs and to maintain said capacity at substantially greater than normal volume. Also, it has been found from tests using a device as shown in Figure 6 , that the increase in tidal volume was greater than what would have been expected from the dead space alone. The mechanism causing this increase is not understood presently because the partial pressure of carbon dioxide in the blood actually decreased.

By way of specific example, there is set forth below dimensions of an exemplary breathing device of the type shown in Figure 6 , but differing therefrom in that the tube 3 is provided with a single air intake opening instead of the 3 openings, 15, length o tube 12.5" ' inside diameter of tube 2.5" thickness of tube wall 0.06" volume of tube 950 cc diameter of single air intake 0.5" r< opening diameter of opening 13 0.25" flap 17 1" x 1.25" polyethylene film' having a thickness of 0.7 mil threshold flap 19 steel spring welded to endcap and designed to open and remain open when the pressure in the tube 3 is at least about 12 cm of water above atmospheric pressure.

The above breathing device can be also fixted with a 0.5" diameter (i.d.) polyethylene tube about 2" long equipped with a mouthpiece through which the patient inhales and exhales.

Various modifications in the use or design of the breathing device of the present invention can be effected. r For example , the device can be used to administer medication to the patient by feeding the medication into the container in vaporized or atomized form. Also, medication can be administered to the patient by placing in the container a material which contains the medication, for example, a material saturated with the medication. A container incorporating such a material -must have a "free volume" of at least about 500 cc. By "free volume" is meant that the container has sufficient space for accommodating the required amount of air.

In summary, it can be said that the present invention provides a relatively simple, but very effective device for greatly expanding the lungs thereby preventing the development of atelectasis and pneumonia in postoperative patients. It should be appreciated that the breathing device of this invention can be used also by individuals who for one reason or another are confined to bed or who are otherwise relatively inactive.

Claims (20)

4134 CLAIMS:

1. A breathing device through which an individual can repeat both the inhaling and ex-haling phases' of respiration comprising a container having a free volume of at least about 500cc, passageway means through which an individual can inhale air from and exhale air into the container and air passages communicating with air at atmospheric pressure allowing air to be' admitted into the container when the individual inhales through said passageway means and to be expelled therefrom when the individual exhales through said passageway means, and means whereby the exhalation force which the individual has to exert to expel air from the container is greater than the inhalation . force needed to cause air to be admitted into the container when the individual inhales.

2. A breathing. device, according to Claim 1 wherein the passageway means and the- air passages are so positioned that at the end of exhalation the container is filled substantially entirely with exhaled air which upon inhalation is first inhaled from the container through the passageway means.

3. A breathing device according to claim 1 or 2 wherein the said means comprises a first valve associated with at least one of said air passages ' for restricting the air flow which is expelled from the container on exhalation as compared with the air flow which is admitted into the container on inhalation.

4. * A breathing device according to claim 1 or 2 wherein the said means prevents exhaled air from being expelled from the container until after the pressure of said exhaled ai in the said container is substantially greater than atmospheric pressure.

5. A breathing device according to claim 4 wherein said means permits air to be expelled from the container when the pressure therein is within the range of about 5 to about 40 cm of water above atmospheric pressure.

6. -6. A breathing device according to claim 5 wherein said means permits air to be expelled from the container when the pressure therein is within the range of about 8 to about 20 cm of water above atmospheric pressure. ·

7. A breathing device according to claim 6, I associated with some of said air passages and adapted to admit air into the containe when air is inhaled passagewy means therefrom by the individual through said and •to prevent air from being expelled from said con- tainer when air is exhaled therein by the individual througn saicP · and a second valve normally closing an air passage which opens to allow air to be expelled from the container when the individual exhales.

8.,· A breathing device according to any preceding claim wherein the container is an elongated tube with the passageway means being positioned at one end of the tube and the air passages being positioned at the other end of said tube.

9. A breathing device according to any preceding claim wherein the volume of the container is no greater than about "3,500 cc.

10. A breathing device according to claim 9 wherein the volume of the container is within the range of about 800 cc. to about 1500 cc.

11. A breathing device according to any preceding claim wherein the said means is responsive to the individual's respiration.

12. A breathing device according to claim 4 • 41349/2 wherein said container is cylindrical in shape, wherein said passageway means includes a tube,_one end of which opens into one end of the container and the other end of which communicates with the at-. * rnosphere, wherein said air passage means comprises a first and second opening in the other end of the container, and wherein said means are responsive to the individual's respiration and comprise a valve associated with said first opening adapted to admit a.ir into the container when air is inhaled therefrom by the individual through said tube and. to prevent air from being expelled from said container when air is exhaled therein" by the individual through said tube and a second valve associated with said second opening adapted to prevent air from entering the container when air is inhaled from said container through said tube and to allow air to be expelled from said -container when the pressure of the air in the container is within the range of about 5 to about 40 cm of water- above atmospheric . pressure .

13. A breathing device according to claim 12 wherein said second valve allows air to be expelled from the container when the pressure, of the air in the container is within the range of about 8 to about 20 cm of water above atmospheric pressure.

14. A breathing device according to claim 12 or 13 wherein the volume of the container is within' the range of about 800 cc to about 1500 cc. t 41349/3 described herein with reference to Figs. 1 to 5 or

15. Fig . 6 of the acoompanying drawings .

16. A method for increasing ventilation and active

17. A method according to claim 16 wherein the individual exhales against a pressure substantially greater than atmospheric pressure throughout the entire phase of exhalation.

18. A method according to claim 17 wherein the individual exhales against a pressure that is at least about 5 cm of water above atmospheric pressure.

19. A method according to claim 17 wherein the individual exhales against a pressure that is at least about 8 cm of water above atmospheric pressure.

20. . A method according to claim 16 for increasing ventilation and active dilation of the lungs of