Intermittant demand aerosol control device

• US 5,415,161 A
• Filed: 09/15/1993
• Issued: 05/16/1995
• Est. Priority Date: 09/15/1993
• Status: Expired due to Fees

• Current Assignee: Steven L. Ryder
• Original Assignee: Steven L. Ryder
• Inventors: Ryder, Steven L.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Deane, Jr., William J.
• Application Number:
  US08/121,746
• Time in Patent Office: 608 Days
• Field of Search: 128/200.24, 128/200.14, 128/200.16, 128/200.23, 128/912, 128/202.21, 424/202, 424/204, 116/137 R, 73/861.21, 73/861.23, 181/141, 310/321, 340/384.6
• US Class Current: 128/200.23
• CPC Class Codes: A61M 11/06 of the injector type
• CPC Class Codes: A61M 15/00 Inhalators drug delivery in endotracheal tubes A61M16/04
• CPC Class Codes: A61M 2016/0024 with an on-off output signal, e.g. from a switch

Abstract

A T connection mouthpiece comprised of a first tubular member with open ends and internal, a tubular member with a smaller diameter having closed ends to define an air chamber. Proximate to the closed end of the air chamber and distal to the mouthpiece is an aperture. A second tubular conduit opens into the first tubular member to be attached to a nebulizer. On the external surface of the T connection mouthpiece and contiguous with the air chamber, is adhered a thin film of polyvinylidene flouride. When the patient inhales through the T connection, airflow is directed to the aperture to generate a fundamental tone, the acoustical energy is converted to electrical energy by the polyvinylidene flouride film. The electrical signal is received and processed by the electronic circuitry which energizes a solenoid valve normally closed to open and to allow for pressurized gas flow to activate the nebulizer. The aerosol is delivered synchronously during the inspiratory phase of the respiratory cycle. At the end of inspiration, the flow through the T connection has ceased and thus no electrical signal. The solenoid valve returns to the normally closed condition to stop the pressurized gas flow and automatically deactivating the nebulizer.

Claims

1. An apparatus for supplying an aerosol in response to an intermittent demand comprising:

a first tubular member having first and second opened ends for airflow therethrough;

an internal substantially tubular member contiguous with an internal surface of said first tubular member, said internal substantially tubular member defining an air chamber within the tubular member, said internal tubular member having closed ends and an aperture near one of the closed ends;

a planar surface projection internal to the first tubular member and external to the internal tubular member, said planar surface projection oriented to deflect airflow in a first direction through said first tubular member toward said aperture of the internal tubular member;

a second surface projection upstream in said first direction of said internal tubular member and said aperture, said second surface being oriented to prevent airflow in a second, opposite direction from entering said aperture;

a window in the first tubular member, said window being arranged to entrain additional airflow through said first tubular member thereby changing the rate of airflow through the first and second opened ends; and

a second tubular conduit perpendicular to and opening into said first tubular member at a point between said opened ends;

wherein

when airflow is effected in said first tubular member, airflow deflected by said planar surface projection through said aperture will generate a vibrational acoustical energy.

2. The apparatus of claim 1 further comprising a piezoelectric element for converting said vibrational acoustical energy into an electrical signal.

3. The apparatus of claim 2, wherein said piezoelectric element comprises polyvinylidene fluoride.

4. The apparatus of claim 2, wherein said piezoelectric element is secured to an external surface of said first tubular member corresponding to the internal contiguous region.

5. The apparatus of claim 2 further comprising an electronic means for receiving and processing said electrical signal.

6. The apparatus of claim 5, wherein said piezoelectric element further comprises electrical connections on each side thereof;

said connections being secured to said first tubular member by conductive tape.

7. The apparatus of claim 5, wherein said piezoelectric element further comprises electrical connections on each side thereof;

said connections being secured to said first tubular member by epoxy.

8. The apparatus of claim 5, wherein said electronic means further comprises a high impedance input amplifier;

band pass, high pass and low pass active filters; and

a phase-locked loop tone decoder circuit.

9. The apparatus of claim 8 further comprising a solenoid operatively connected to valve means for selectively admitting into said second tubular member a pressurized gas flow, said solenoid being operatively connected and controlled by said electronic means.

10. The apparatus of claim 9, wherein said valve means further comprises vent means for venting a pressurized gas flow to the ambient.