Mini pneumatic mechanical pulmonary ventilator

• US 6,431,169 B1
• Filed: 12/03/1999
• Issued: 08/13/2002
• Est. Priority Date: 08/05/1999
• Status: Expired due to Fees

• Current Assignee: Vent-Logos Sistemas Logicos SA
• Original Assignee: Vent-Logos Sistemas Logicos SA
• Inventors: do Val, Humberto Ribeiro, de Azeredo, Wilson Valadao
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): MITCHELL, TEENA KAY
• Application Number:
  US09/454,630
• Time in Patent Office: 984 Days
• Field of Search: 128/200.24, 128/204.18, 128/204.21, 128/204.23, 128/204.24, 128/204.25, 128/204.26, 128/205.16, 128/205.18, 128/205.24
• US Class Current: 128/200.24
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/127 by Venturi effect, i.e. entrainment mixers

Abstract

The present invention discloses a pneumatic, mechanical, pulmonary ventilator apparatus. The apparatus operates to dilute and limit the pressure of various gases delivered to a patient. The function of the apparatus may be described as an astatic multi-vibrator, which is activated by pressurized gas (e.g., such as oxygen or medical compressed air). The gas output of the apparatus may be described as a square wave, wherein the high wave phase corresponds to the inspiratory phase (the duration is the inspiratory time) and the low wave phase corresponds to the expiratory phase (the duration is the expiratory time). The sum of the two phases corresponds to the respiratory cycle. The device includes a rubber diaphragm having a ring shape to cyclically block a gas source aperture inlet. An adjustable needle valve, which controls the gas pressure in a small chamber on the opposite side of the diaphragm, together with a helical spring provide for tuning the two cycle phases. A venturi system limits the delivered pressure of gas to the patient and remains open during all cycles, thereby enabling the patient to breath independent of the cycle of the apparatus.

Claims

1. A mini pneumatic mechanical pulmonary ventilator comprising:

a single moving part, wherein the single moving part is a diaphragm including an outer edge, a flexible lateral part within the outer edge, and a ring-shaped salience formed on a first side of the diaphragm;

the ventilator having a gas inlet and a gas outlet, the gas inlet adapted to receive gas pressurized above ambient atmospheric pressure;

gas entering the ventilator through the gas inlet applying pressure to the first side of the diaphragm within the ring shaped salience, and a spring within a chamber applies pressure on a second opposing side of the diaphragm;

the pressure of the gas entering the ventilator from the gas inlet being sufficient to overcome the pressure of the spring and moving the diaphragm toward the chamber, opening a pathway for the gas to pass beyond the diaphragm;

the pathway allowing gas to move toward the gas outlet and toward a needle valve, the needle valve cooperating with a opening to allow some of the gas to leak past the needle valve and enter the chamber;

the pressure of the gas leaking into the chamber acting on the second side of the diaphragm, adding to the pressure being applied to the second side of the diaphragm by the spring until the pressure on the second side of the diaphragm is sufficient to move the diaphragm away from the chamber, blocking the pathway and holding the incoming gas from passing the diaphragm;

the gas within the chamber leaking past the needle valve out of the chamber into the passageway, reducing the pressure in the chamber until the pressure of the incoming gas within the ring-shaped salience on the first side is sufficient to move the diaphragm toward the chamber and allow gas from the gas inlet to enter the pathway;

a period of time when the pathway is closed to gas from the gas inlet defining a first cycle phase, and a period of time when the pathway is open to gas from the gas inlet defining a second cycle phase, the first and second phases together defining a cycle.

2. The mini pneumatic mechanical pulmonary ventilator of claim 1, wherein the ventilator includes a single diaphragm, the spring is a helicoidal spring, the chamber is about 2.5 cm³ in volume, and a single needle valve controls the frequency of the phases on the cycle, the frequency of the phases determined by the rate of leakage of gas into and out of the chamber past the needle valve.

3. The mini pneumatic mechanical pulmonary ventilator of claim 2, wherein a ratio of the phases of the cycle is determined by the amount of pressure applied by the spring acting on the second side of the diaphragm and wherein the amount of pressure applied by the spring can be varied by the adjusting the depth of penetration of a threaded needle valve carcass into the chamber, the needle valve carcass threadably received within the ventilator and acting on a side of the spring away from the second side of diaphragm and the needle valve threadably received within the needle valve carcass.

4. The mini pneumatic mechanical pulmonary ventilator of claim 3, wherein the ventilator is contained within a unitary housing and the housing provides protection to the ventilator against falls or other physical impact.

5. The mini pneumatic mechanical pulmonary ventilator of claim 4, wherein the operation of the ventilator through the phases of the cycle does not require the application of any energy beyond that provided by the pressure of the gas entering the ventilator through the gas inlet.

6. A mini pneumatic mechanical pulmonary ventilator comprising:

a) a diaphragm including an outer edge, a flexible lateral part within the outer edge, and a ring-shaped salience formed on a first side of the diaphragm;

b) a spring within a chamber for applying pressure on a second opposing side of the diaphragm;

c) a gas inlet and a gas outlet, the gas inlet adapted to receive gas pressurized above ambient atmospheric pressure,

d) a pathway in fluid connection with the gas inlet when the diaphragm moves toward the chamber;

e) a needle valve in fluid communication with the pathway and cooperating with a opening to allow some of the gas to leak past the needle valve and enter the chamber; and

f) wherein in a first cycle phase;

gas entering the ventilator through the gas inlet applies pressure to the first side of the diaphragm within the ring shaped salience and the pressure of the gas entering the ventilator from the gas inlet is sufficient to overcome the pressure of the spring and moves the diaphragm toward the chamber, opening the pathway for the gas to pass beyond the diaphragm and toward the gas outlet and the needle valve, the pressure of the gas leaking into the chamber acts on the second side of the diaphragm and adds to the pressure being applied to the second side of the diaphragm by the spring until the pressure on the second side of the diaphragm is sufficient to move the diaphragm away from the chamber, blocking the pathway and holding the incoming gas from passing the diaphragm, the length of the first cycle phase defined as a period of time when the pathway is closed to gas from the gas inlet; and

in a second cycle phase;

the gas within the chamber leaking past the needle valve out of the chamber into the passageway, reducing the pressure in the chamber until the pressure of the incoming gas within the ring-shaped salience on the first side is sufficient to move the diaphragm toward the chamber and allow gas from the gas inlet to enter the pathway the length of the second cycle phase defined as a period of time when the pathway is open to gas from the gas inlet;

g) the first and second phases together defining a cycle.