Nebulizer device

[54] NEBULIZER DEVICE

[76] Inventor: John M. Hoppough, 921 S.

Macomber, Greenville, Mich. 48838

[21] Appl. No.: 147,231

[22] Filed: Jan. 22,1988

[51] Int. CI.* A61M 11/02

[52] U.S. CI 128/200.14; 128/200.21;

128/203.12; 128/203.25

[58] Field of Search 239/338; 128/200.14,

128/200.19, 200.21, 203.12, 203.16, 203.25, 203.29, 205.11, 200.18

[56] References Cited

U.S. PATENT DOCUMENTS

Re. 30,046 7/1979 van Amerongen 239/338

733,027 7/1903 Goldan 128/203.25

1,176,886 3/1916 Ermold 128/203.25

3,547,351 12/1970 Hruby, Jr 239/338

3,836,079 9/1974 Huston 239/338

3,913,607 10/1975 Price 128/205.11

04,243,396 1/1981 Cronenberg 239/338

4,267,974 5/1981 Kienholz et al 128/203.25

4,319,566 3/1982 Hayward et al 128/203.25

4,427,004 1/1984 Miller 128/200.21

4,595,002 6/1986 Michaels et al 128/205.11

4,612,926 9/1986 Boiarski et al 128/205.11

4,767,576 8/1988 Bagwell 128/200.21

FOREIGN PATENT DOCUMENTS

6911 3/1909 United Kingdom 128/205.11

616089 1/1949 United Kingdom 239/338

OTHER PUBLICATIONS

Armour Pharmaceutical Company Brochure, ARM-A-VIAL LV Large Volume Respiratory Therapy System.

Dec. 1987 issues, Respiratory Care, p. 1163.

. Primary Examiner—William Pieprz
Assistant Examiner—Kimberly L. Asher
Attorney, Agent, or Firm—Price, Heneveld, Cooper,
DeWitt & Litton

[57] ABSTRACT

A nebulizer device having an atmosphere adjusting collar both slidably and rotatably mounted on the housing so as to adjust restriction of atmosphere inlet ports on the housing. An additional high oxygen port on the nebulizing nozzle is restricted by a flow rate adjusting collar. The flow rate adjusting collar is coupled to the atmosphere adjusting collar so as to maintain rate of flow as the atmospheric inlet is adjusted, but the atmospheric inlet is automatically adjusted as the oxygen flow rate is adjusted. An atmosphere entraining valve located downstream of the nebulizer housing provides additional entrainment of atmosphere to further reduce the fraction of inspired oxygen in the humidified air.

33 Claims, 2 Drawing Sheets

1

NEBULIZER DEVICE

BACKGROUND OF THE INVENTION

The present invention relates to nebulizer devices, 5 and in particular to nebulizer devices used in medical applications.

Nebulizers are used in medical environments to humidify the air supplied to a patient. Heretofore a wide variety of nebulizer designs have been developed and 10 have been used with a variety of patient ventilating systems. In a typical system a nebulizer is coupled to a flowmeter which is in turn coupled to an oxygen source, such as an oxygen tank or hospital oxygen supply system. The flowmeter is used to adjust the oxygen 15 flow rate supplied to the nebulizer. The nebulizer normally includes some type of nozzle that provides an air jet adjacent a fluid supply, which typically consists of a capillary tube that leads to a fluid supply bottle. The oxygen jet induces liquid flow up the capillary tube to 20 the jet where the fluid is entrained as a fine aerosol mist. The humidified oxygen is then passed through tubing to some type of respiratory device, such as a respirator mask, endotracheal tube, oxygen tent or the like.

In the past nebulizers have also been used to regulate 25 the oxygen concentration of the gas supplied to the patient, referred to as the "fraction of inspired oxygen" (FIO2). For this purpose nebulizers typically have some type of valving system that allows atmospheric gas to vent into the oxygen flow at the nozzle region. The 30 oxygen jet is used to entrain and mix with the atmospheric gases. Adjustment of the valving mechanism * therefore regulates the atmosphere to oxygen ratio that is forced through the nebulizer device to the patient. However, since the oxygen flow through the nebulizer 35 is used to induce a vacuum that draws atmosphere into the nozzle region as well as draws fluid up the capillary tube and into the oxygen stream, the size of the vent mechanism opening is limited. If an excessive atmospheric opening is provided, the fluid entraining oxygen 40 will simply exhaust out through the vent mechanism rather than being directed toward the patient.

One substantial problem associated with previous nebulizers is the restriction of air flow to the patient. In instances in which the patient requires a low fraction of 45 inspired oxygen, a relatively large amount of atmospheric gases may be drawn in through the nebulizer and supplied to the patient. In such an application the venting mechanism is fully opened, resulting in a high flow rate to the patient and a low fraction of inspired 50 oxygen or oxygen percentage. In other instances, however, the patient may require a high fraction of inspired oxygen. In these applications the vent mechanism must be substantially closed, reducing the amount of atmospheric gases which are supplied to the patient and thus 55 dramatically reducing the overall gas flow to the patient. Nonetheless the patient normally still requires a relatively high overall flow rate for respiration. In such instances one solution is to provide two nebulizer systems in order to double the flow rate to the patient yet 60 maintain the appropriate fraction of inspired oxygen. Alternatively, the respiratory tubing downstream of the nebulizer may have an additional oxygen tube leading from another flowmeter which bleeds in oxygen to the previously humidified gas mixture. Although this per- 65 mits the fraction of inspired oxygen to be increased, the atmosphere venting mechanism must be adjusted to accommodate this increased oxygen content and the

2

nebulizer is not calibrated for this supplemented flow rate, so that this varying of the flow rate renders inaccurate the regulation of fraction of inspired oxygen. Inconsistent oxygen and flow delivered to the patient may result.

In another attempt to solve these problems, an additional valve has been placed on the nebulizer nozzle, which when opened permits additional oxygen to pass through another port on the nebulizer nozzle. This structure suffered from a similar problem as the flowmeter-nebulizer sequence noted above, in that the atmosphere venting mechanism is calibrated and accurate only as to a given flow rate of oxygen through the nebulizer. Changing this flow rate renders inaccurate the atmosphere venting mechanism and is a potential hazard.

In the above systems, inaccurate oxygen concentrations as a result of varying the flow rate can be potentially dangerous to the patient. The common practice of connecting a flowmeter and nebulizer poses such a potential hazard. Even in situations that do not pose a potential hazard to the patient, such multiple adjustments are confusing and difficult to estimate. Multiple systems require duplication of equipment which increases the expense of administering this type of therapy.

SUMMARY OF THE INVENTION

The present invention is preferably embodied in a nebulizer that provides adjustment both of the oxygen flow rate through the nebulizer and atmospheric flow into the nebulizer unit. The mechanism for adjusting the atmospheric inlet is coupled with the mechanism for adjusting the flow rate, so that as the flow rate is varied the atmospheric inlet is simultaneously adjusted. Nonetheless, adjustment of the atmospheric inlet does not necessarily adjust the flow rate through the nebulizer. This provides the nebulizer with the ability to increase the oxygen flow through the device in instances when very little atmospheric gases are to be mixed with the oxygen, yet maintain a properly calibrated atmospheric inlet and thus an appropriate fraction of inspired oxygen that is supplied through the unit. Further, for applications in which a very low fraction of inspired oxygen is desired, the nebulizer device provides an atmospheric inlet and atmosphere entraining nozzle located in the respiratory ducting between the nebulizer and the patient.

In a preferred embodiment the nebulizer provides a collar with atmospheric inlet apertures or vents slidably and rotatably mounted on the housing. A collar on the nebulizer nozzle opens an additional port or jet to increase oxygen flow. The two collars are coupled, while one atmosphere inlet is calibrated for single nozzle port flow and the other atmosphere inlet is calibrated for double nozzle port flow.

With the present nebulizer device a high flow rate is maintained even though a high fraction of inspired oxygen is provided through a single nebulizer device. The nebulizer device is quickly and easily adjusted, and additional flowmeters and the like are not required. The nebulizer device in a preferred embodiment provides a fraction of inspired oxygen range of from one hundred percent (1.0) to twenty eight percent (0.28). With an additional air entraining valve in the respiratory tube leading to the patient, the fraction of inspired oxygen is