NEBULIZING APPARATUS AND SYSTEM

• US 3,828,773 A
• Filed: 09/22/1972
• Issued: 08/13/1974
• Est. Priority Date: 09/22/1972
• Status: Expired due to Term

• Current Assignee: Louis L. Kocsis, Max S. Sadove, Roman Buch
• Original Assignee: Louis L. Kocsis, Max S. Sadove, Roman Buch
• Inventors: Buch, Roman, Kocsis, Louis L., Sadove, Max S.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Cohen, Lee S.
• Application Number:
  US05/291,232
• Time in Patent Office: 690 Days
• Field of Search: 128/194,DIG.2,193,172,173,191,186,24A 239/338,102 259/DIG.44 310/8.1,8.2,9.1,9.2,8.3
• US Class Current: 128/200.16
• CPC Class Codes: A61M 15/0085 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: Y10S 261/48 Sonic vibrators
• CPC Class Codes: Y10S 261/65 Vaporizers

Abstract

An ultrasonic nebulizing apparatus and system including a pzt crystal, supported in a container adapted to support a nebulization cup at a position spaced from the transducer; the container also adapted to contain a fluid coupling column. An oscillator, when energized causes the crystal to oscillate at its ultrasonic mechanical resonant frequency, the oscillator being designed to oscillate at a frequency governed by the mechanical resonant frequency of the crystal. The system includes a safety circuit associated with the oscillator and including the container, the cup and the coupling column, which is effective to deenergize the system in the absence of operational conditions within the system.

Claims

1. An ultrasonic nebulizing system comprising:

an ultrasonic transducer having an ultrasonic resonant mechanical frequency;

a nebulizing cup adapted to contain a solution to be nebulized;

a container supporting said transducer and said cup in spaced apart relation to said transducer;

a fluid column within said container for coupling the ultrasonic energy generated by said transducer to said cup supported by said container, the absence of fluid coupling between said transducer and said cup supported by said container defining an absence of operational conditions within said system;

electric drive circuit means electrically connected to said transducer, said drive circuit means when energized generating an a.c. signal causing said transducer to oscillate at its mechanical resonant frequency; and

safety circuit means operatively associated with said drive circuit means for deenergizing said drive circuit means and said transducer in response to the absence of operational conditions within said system.

2. A system as claimed in claim 1 including means for energizing said safety circuit means in response to the existence of operational conditions within said system to effect energization of said drive circuit means, and for deenergizing said safety circuit means in response to the absence of said operational conditions within said system to effect said deenergization of said drive circuit means.

3. A system as claimed in claim 2 wherein one of said operational conditions is the existence of fluid coupling between said transducer and said cup supported by said container, said means for energizing and deenergizing said safety circuit means including sensing circuit means including said fluid coupling cOlumn responsive to the presence of said fluid coupling to energize said safety circuit means and responsive to the lack of said fluid coupling to deenergize said safety circuit means.

4. A system as claimed in claim 3 wherein said sensing circuit means incorporates a d.c. circuit path through said fluid coupling column, said sensing circuit means operative to deenergize said safety circuit means in response to the opening of said d.c. circuit path.

5. A system as claimed in claim 4 wherein said d.c. circuit path includes first contact means disposed in proximity to said transducer and second contact means spaced from said transducer, and said fluid coupling column extending therebetween, said d.c. circuit path opening when there is insufficient fluid in said coupling column to engage both said first and second means and alternatively upon movement of said second contact means out of engagement with said coupling column.

6. A system as claimed in claim 5, wherein said second contact means includes a fixed contact on said container spaced away from said coupling column and a removable contact on said cup supported by said container, said removable contact engaging both said fixed contact and said coupling column when said cup is supported by said container to complete said d.c. circuit path.

7. A system as claimed in claim 2 wherein one of said operational conditions is the presence of said cup supported by said container, said means for energizing and deenergizing said safety circuit means including sensing circuit means including electrical contact means on said cup and said container electrically engaging when said cup is supported by said container, said sensing circuit means responsive to the absence of such electrical engagement between said contact means to deenergize said safety circuit means.

8. A system as claimed in claim 1 wherein said electric drive circuit comprises an oscillator circuit, wherein said transducer is connected to said oscillator circuit as a high Q load circuit, said oscillator circuit being designed to oscillate at a resonant frequency corresponding to the nominal mechanical resonant frequency of said transducer or at harmonics or sub-harmonics thereof, said oscillator circuit including circuit means effecting actual oscillation thereof at a resonant frequency corresponding to the actual mechanical resonant frequency of said transducer, or at harmonics or sub-harmonics thereof, which actual mechanical resonant frequency may differ from said nominal mechanical resonant frequency.

9. A system as claimed in claim 8 wherein said circuit means includes amplifying circuit means and tuned circuit means of the type exhibiting maximum impedance at resonance connected to said amplifying circuit means, the designed resonance of said tuned circuit means being equal to the nominal resonant frequency of said oscillator, a positive feedback circuit provided by the internal interelectrode capacitance of said amplifying means, whereby the actual resonant frequency of said oscillator is determined by the actual mechanical resonant frequency of said transducer.

10. In an ultrasonic nebulizing system, a crystal supported by a container and adapted to mechanically oscillate at an ultrasonic resonant frequency in response to an a.c. drive signal having a frequency equal to said resonant frequency, to harmonics thereof or to subharmonics thereof, a cup adapted to contain a solution to be nebulized supported by said container at a position spaced from said crystal, said crystal being operatively coupled to said cup through a fluid coupling column, an oscillator for generating said a.c. drive signal, a power source, normally open switch means connecting said power source to said oscillator, means coupling said a.c. drive signal to said crystal, safety control circuit means operative when energized to close said normally open switch means and effect energization of said oscillator, biasing meAns connected between the input of said safety control circuit means and said power source and including safety circuit sensing means connected across said crystal, said safety circuit sensing means incorporating a d.c. circuit path including said fluid coupling column and contact means on said cup, said biasing means producing a d.c. bias voltage to energize said safety control circuit in response to said d.c. circuit path being closed.

11. In a system as claimed in claim 10, including additional electrical components connected to said source through said normally open switch means, whereby said additional components are energized in response to the energization of said safety control circuit means.

12. In a system as claimed in claim 10, including alarm indicating means, normally closed switch means connecting said alarm indicating means to said power source, said normally closed switch means opening in response to the energization of said safety control circuit means and closing in response to deenergization thereof to actuate said alarm indicating means.

13. In an ultrasonic nebulizing system, having a container, a cup supported in said container, an ultrasonic crystal and a fluid column within said container for coupling said crystal to said cup;

a crystal holder structure for supporting said crystal in a wall of said container comprising;

a generally hollow open ended electrically conductive housing extending through said wall and attached thereto, the interior of said housing having a cross-sectional configuration complementary to the peripheral configuration of said crystal, the inner end of said housing, disposed within said container, formed with a retaining lip, said crystal being disposed within said housing and adjacent to said retaining lip, with its inner surface exposed to said fluid coupling column, means disposed between said lip and the peripheral portion of said crystal to provide a fluid seal therebetween, a first electrically conductive electrode formed around the periphery of said crystal;

a removable electrically conductive retaining ring disposed within said housing against said first electrode and the outer peripheral edge of said crystal to retain said crystal in place, a second electrode in electrical contact with the outer surface of the said crystal and spaced from said first electrode, and a collar removably attached to said housing, for retaining said second electrode in electrical contact with said crystal.

14. In the system of claim 13, wherein said housing, said retaining ring and said collar are all electrically conductive, said first electrode including a first conductive coating on the inner surface of said crystal and extending to and around the periphery thereof into electrical contact with said housing and said retaining ring, and said second electrode including a second conductive coating on the outer surface of said crystal electrically insulated from said first conductive coating, and wherein said second electrode is supported by an electrically insulated disc in contact with said second conductive coating, said disc being retained in place between said retaining ring and said collar.

15. In a system as claimed in claim 14 including an oscillator having an output and a ground connection for driving said crystal at its resonant frequency, and single wire shielded cable means, the single wire of which is connected to said electrode and to the output of said oscillator and the shield of which is connected to said collar and to the ground connection of said oscillator.

16. In a system as claimed in claim 15, including a safety sensing circuit connected across said crystal and including a contact on the cup electrically connectable to said housing through said fluid coupling column and engageable to make electrical contact with a contact on said container disposed out of contact with said fluid coupling column to complete a circuit from said grounded housing through said fluid column to said container contact.

17. In a system as claimed in claim 16, said safety sensing circuit further including a capacitor connected between said container contact and said grounded shield and a choke coil connected between said container contact and said single wire of said cable means, whereby the output of said oscillator is electrically blocked from said sensing circuit by said choke coil and said coupling column is exposed only to a d.c. signal.