Method and apparatus for driving a transducer of an inhalation device

• US 8,371,294 B2
• Filed: 02/25/2009
• Issued: 02/12/2013
• Est. Priority Date: 02/29/2008
• Status: Active Grant

• Current Assignee: MicroDose Therapeutx, Inc. (Teva Pharmaceutical Industries Limited)
• Original Assignee: MicroDose Therapeutx, Inc. (Teva Pharmaceutical Industries Limited)
• Inventors: Gumaste, Anand, Bowers, John, Weitzel, Douglas
• Primary Examiner(s): RICHMAN, GLENN E
• Application Number:
  US12/392,686
• Publication Number:
  US 20090217925A1
• Time in Patent Office: 1,448 Days
• Field of Search: 128/200.16, 128/200.14, 128/203.12, 128/203.14, 128/203.15, 128/203.19, 128/200.24
• US Class Current: 128/200.24
• CPC Class Codes: A61M 15/001 using ultrasonic means
• CPC Class Codes: A61M 15/0028 using prepacked dosages, one for each application, e.g. capsules to be perforated or broken-up
• CPC Class Codes: A61M 15/0085 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: A61M 2202/064 Powder
• CPC Class Codes: B05B 17/0669 Excitation frequencies
• CPC Class Codes: B06B 1/0276 with simultaneous generation, e.g. with modulation, harmonics
• CPC Class Codes: H10N 30/802 Drive or control circuitry or methods for piezoelectric or electrostrictive devices not otherwise provided for

Abstract

An inhaler is disclosed wherein medicament in a flat-bottomed container is aerosolized with a vibrator piezoelectric transducer. The transducer is driven by a signal that excites multiple harmonic frequencies to create a complex pattern of oscillations. A circuit for generating the drive signal to the transducer is also disclosed.

Claims

1. A method of driving a transducer in an inhaler, having a piezoelectric transducer as a vibrator, which comprises providing a signal comprising a waveform that has a fundamental frequency equal to a primary frequency of the transducer to produce oscillations, the signal exciting the primary resonant frequency of the transducer and, in addition, at least one secondary resonant frequency of the transducer.

2. The method of claim 1, wherein the signal is a waveform comprising two sinusoidal signals at two frequencies corresponding to the primary resonant frequency and the secondary resonant frequency.

3. The method of claim 1, wherein the transducer is used to aerosolize medicament contained in a blister pack.

4. The method of claim 3, wherein friction between the blister pack and the transducer due to the oscillations is minimized.

5. The method of claim 3, wherein the medicament is a dry powder.

6. The method of claim 3, wherein the medicament is a liquid.

7. The method of claim 1, wherein the transducer resonates at an nth harmonic of its primary resonance frequencies, wherein n is a whole number selected from the group consisting of 2, 4, 6 and 8.