Inhalation device

Abstract

A dry inhaler system includes a vibrating mechanism. A supply of a dry powder is operatively coupled to the vibrating mechanism. A power source communicates with the vibrating mechanism. A sensor communicates with the vibrating mechanism. A feedback control communicates with the sensor and the power source. The feedback control controls power delivered to the vibrating mechanism relative to information provided by the sensor about the performance of the vibrating mechanism.

Claims

1. A control circuit for a dry powder inhaler having an inhaling airflow passageway, having a vibrating mechanism provided proximate to the inhaling airflow passageway; a supply of a dry powder operatively coupled to the vibrating mechanism; a power source in communication with the vibrating mechanism; and a sensor in communication with the vibrating mechanism, wherein the sensor is positioned to measure a vibration of the vibrating mechanism; said control circuit comprising an actuation controller for permitting power to be supplied to the vibrating mechanism; a feedback control in communication with the sensor and the power source, whereby the feedback control controls power delivered to the vibrating mechanism based on a vibration measured by the sensor after the power delivered to the vibrating mechanism is removed upon the vibrating being driven to a steady state condition; and a frequency sweep generator connected between the power source and the vibrating mechanism for controlling a characteristic of power delivered to the vibrating mechanism whereby vibration of the vibrating mechanism releases powder directly into the inhaling airflow passageway.

2. The control circuit for the dry powder inhaler of claim 1, further comprising a memory in communication with the feedback control, whereby the memory stores at least one communication from the sensor to the feedback control relative to at least one communication from the feedback control to the power source.

3. The control circuit for the dry powder inhaler of claim 1, further comprising a peak power detector in communication with the sensor.

4. The control circuit for the dry powder inhaler of claim 1, wherein the feedback control correlates a plurality of power forms delivered to the vibrating mechanism with a plurality of outputs from the sensor.

5. The control circuit for the dry powder inhaler of claim 4, wherein the feedback controller identifies a power characteristic of the plurality of power forms delivered to the vibrating mechanism correlated with a highest output from the plurality of outputs from the sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

(2) FIG. 1 is a cross-sectional side view of an inhaler, in accordance with a first exemplary embodiment of the present invention; and

(3) FIG. 2 is an illustration of a block diagram of the vibration control system for the inhaler shown in FIG. 1, in accordance with the present invention first exemplary embodiment of the present invention.

(4) FIG. 3 is a flowchart illustrating a method of providing the abovementioned dry powder inhaler, in accordance with the first exemplary embodiment of the invention.

DETAILED DESCRIPTION

(5) FIG. 1 is a cross-sectional side view of an inhaler 2, in accordance with a first exemplary embodiment of the present invention. As shown in FIG. 1, air 10, or other fluid, enters the airflow passageway 12. The flow of air 10 may be triggered by respiratory activity of a patient inhaling on the device 2. The flow of air 10 moves from a distal end 14 of the inhaler 2, through the passageway 12, to a proximate end 46 of the inhaler 2. A mouthpiece may be provided for the patient at the proximate end 46 of the inhaler 2, from which the patient inhales.

(6) A vibrating mechanism 28 is provided proximate to a third opening 16 in the inhaler 2. The vibrating mechanism 28 may include, but is not limited to, a piezoelectric element, an ultrasonic acoustic transducer, or any other electro/mechanical vibratory mechanism. A container 20 is provided proximate to the vibrating mechanism 28. The container 20 and vibrating mechanism 28 are at least sufficiently proximate to allow the container 20 to be vibrated by the vibrating mechanism 28. The container 20 may be a blister capsule such as the blister capsule described in U.S. Pat. No. 7,318,434 assigned to MicroDose Technologies, Inc, the disclosure of which is incorporated herein in its entirety. The container 20 contains a powder 50 to be disaggregated by the vibrating mechanism 28. The inhaler 2 may be structured to allow the container 20 to be discarded and replaced after each use of the inhaler 2.

(7) Control circuitry 48 is contained in the inhaler 2. The control circuitry may be embodied as an application specific integrated circuit chip and/or other integrated circuit chip. The control circuitry 48 may take the form of a microprocessor, or discrete electrical and electronic components and may include one or more elements remotely connected to the inhaler 2. The control circuitry 48 determines an amount of power to be supplied from a power source 26 to the vibrating mechanism 28. The control circuitry may control amplitude and/or frequency of actuating power to be supplied from the power source 26 to the vibrating mechanism 28, which will impact a level to which the vibrating mechanism 28 vibrates. The actuating power may be provided by an electrical connection 22 between the vibrating mechanism 28 and the power source 26, with the control circuitry 48 at least partially controlling the electrical connection 22. The electrical connection 22 may include a circuit device that transforms a DC power provided by the power source 26 to AC power for the vibrating mechanism 28, which circuit devices are known to those having ordinary skill in the art of circuit design.

(8) The vibrating mechanism 28 may include a piezoelectric element 28 made of a material that has a high-frequency, and preferably, ultrasonic resonant vibratory frequency (e.g., about 15 to 100 MHz), and is caused to vibrate with a particular frequency and amplitude depending upon the frequency and/or amplitude of excitation electricity applied to it. Examples of materials that can be used to create the piezoelectric element include quartz and polycrystalline ceramic materials (e.g., barium titanate and lead zirconate titanate). Advantageously, vibrating the piezoelectric element at ultrasonic frequencies minimizes noise with vibrating the piezoelectric element at lower (i.e., below ultrasonic) frequencies.

(9) FIG. 2 is an illustration of a block diagram of the vibration control system for the inhaler shown in FIG. 1, in accordance with the present invention first exemplary embodiment of the present invention. As will be understood by those skilled in the art, although the functional components shown in FIG. 1 are directed to one possible physical embodiment of the present invention. The components of FIG. 1 could be appropriately modified, altered, and/or rearranged without departing from the scope of the present invention and other inhaler configurations may benefit from the vibration control system described herein.

(10) Control circuitry 48 may include am actuation controller 70 and a control subsystem 72. The actuation controller 70 may include a switching mechanism for permitting actuating power to be supplied from the power source 26 to the control subsystem 72 depending upon the signals supplied to it from an airflow sensor 40. The airflow sensor 40 would limit ignition of the vibrating mechanism 28 to occasions when someone is inhaling from the proximate end 46 of the inhaler 2. A toggle switch 32 may also be provided with the control circuitry 48, to make sure the power source 26 is drained due to ambient airflow. In other words, controller 70 permits actuating power to be supplied from the power source 26 to the control subsystem 72 when the toggle switch 32 is set to the ON position and the airflow sensor 40 supplies a signal to the actuation controller 70 that indicates that inhalation is occurring through the airflow passageway 12. However, the actuation controller 70 does not permit actuating power to flow from the power source 26 to the system 72 when either the toggle switch 32 is set to OFF or the signal supplied to the controller 70 from the airflow sensor 40 indicates that inhalation is not taking place through the airflow passageway 12.

(11) When the actuation controller 70 first permits actuating power to be supplied from the power source 26 to the control subsystem 72, the control subsystem 72 may enter an initialization state wherein a controllable circuit 74 for supplying a predetermined frequency and amplitude of actuating power is caused to generate control signals. The control signals cause a pump circuit 80 to transmit an initial desired frequency and amplitude of actuating power, based upon stored values thereof stored in an initialization memory 82. The controllable circuit 74 may include a frequency sweep generator 76 and a frequency generator 78. The signals generated by the controllable circuit 74 may be supplied to charge the pump circuit 80 to cause the pump circuit 80 to supply the vibrating mechanism 28 with actuating power as specified by the control signals.

(12) Preferably, the initial frequency and amplitude of actuating electricity supplied to the vibrating mechanism 28 is pre-calibrated to cause the vibrating mechanism 28 to be driven to a steady state condition. As will be appreciated by those skilled in the art, substantially maximum transfer of vibratory power from the vibrating mechanism 28 to the powder 50 in the container 20 takes place when the piezoelectric element 90 is driven to vibrate at an approximately steady state. It has been found that this results in significant disaggregation and suspension of the powder 50 from the container 20 into the air to be inhaled by the user. However, when the container 20 or powder 50 is placed on the vibrating mechanism 28, the weight and volume of the container 20, with the weight, volume, and particular size of the powder 50 to be disaggregated, can change the vibration characteristics of the vibrating mechanism 28, and cause the vibrating mechanism 28 to vibrate at something other than its resonant frequency. The resulting frequency can cause reduced vibratory energy transfer to the powder 50 from the vibrating mechanism 28 and, thereby, lessen the efficiency of the vibrating mechanism 28 in disaggregating and suspending the powder 50 in the air inhaled by the user.

(13) In the control circuitry 48, once steady state occurs, the supply signal from the pump circuit 80 is stopped. The vibrating mechanism 28 should continue to vibrate due to its momentum. If the vibrating mechanism 28 includes a piezoelectric element, continued vibration will induce a voltage due to the piezoelectric effect, which can be measured by a sensor 88, such as a voltmeter, in the first few cycles after the supply signal from the pump circuit 80 is stopped. The voltage observed should be directly proportional to the displacement of the piezoelectric element 90.

(14) The frequency sweep generator 76 and the frequency generator 78 systematically generate control signals indicative of many different amplitudes and frequencies of electricity for being supplied to the vibrating mechanism 28 by the pump circuit 80. As the frequency generator 78 cycles through different frequencies and amplitudes, and the signal supplied by the pump circuit 80 is intermittently stopped, the instantaneous continued vibration characteristics of the vibrating mechanism 28 for each of these different frequencies and amplitudes are detected by the sensor 88, which transmits this information to a peak power detector 86. The peak power detector 86 analyzes the output of the sensor 88 and signals a sample and hold feedback controller 84 when the power transfer characteristics are at a detected local maxima. The sample and hold feedback controller 84 correlates these local maxima with the frequencies and amplitudes commanded by the controllable circuit 74 to be supplied to the vibrating mechanism 28. The sample and hold feedback controller 84 may store information in a memory 500 in communication with the sample and hold feedback controller 84.

(15) After the frequency sweep generator 76 and the frequency generator 78 has finished sweeping through the frequencies and amplitudes of power supplied to the vibrating mechanism 28, the sample and hold feedback controller 84 causes the controllable circuit 74 to cycle through the frequencies and amplitudes of power that resulted in local maxima, and determine which of these frequencies and amplitudes results in a detected optimal power transfer characteristics through the vibrating mechanism 28.

(16) In operation, the container 20 may be punctured and engaged with the surface of the vibrating mechanism 28 in the manner described previously. The toggle switch 32 is placed in the ON position and the user inhales air through the proximate end 46. The inhalation of air 10 is sensed by the airflow sensor 40 and is signaled to the actuation controller 70, which causes power to be supplied to the control subsystem 72. The control subsystem 72 then adjusts the amplitude and frequency of actuating power supplied to the vibrating mechanism 28 until optimized for optimal disaggregation and suspension of the powder 50 from the container 20 into the air stream.

(17) FIG. 3 is a flowchart 200 illustrating a method of providing the abovementioned dry powder inhaler 2, in accordance with the first exemplary embodiment of the invention. It should be noted that any process descriptions or blocks in flow charts should be understood as representing modules, segments, portions of code, or steps that include one or more instructions for implementing specific logical functions in the process, and alternate implementations are included within the scope of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.

(18) As is shown by block 202, a vibrating mechanism 28 is driven to an approximate steady state using a first power input. The first power input is removed, wherein a vibration of at least a portion of the vibrating mechanism 28 continues (block 204). The vibration of the vibrating mechanism 28 is sensed after the voltage input is removed (block 206). The steps of driving, removing, and sensing with a plurality of different power inputs are repeated (block 208), The voltage input that produced a largest sensed vibration is determined (block 210). The vibrating mechanism 28 is positioned to disaggregate the dry powder 50 (block 212).

(19) It should be emphasized that the above-described embodiments of the present invention, particularly, any preferred embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.