Title:  Powder inhaler

United States Patent:  6,328,033

Appl. No.:  326111

An inhaler device for administration of a dry powder to a patient includes a package containing a dose of the dry powder and a magnetic field generator, which produces a magnetic field in a vicinity of the package. The magnetic field causes motion of particles of the powder so as to deaggregate the powder in the package, whereby the powder is inhaled by the patient. Preferably, the package includes walls made of a flexible material, which vibrate under the influence of the magnetic field so as to impart the motion to the particles.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide improved devices and methods for delivery of dry powders to a patient by inhalation.

It is a further object of some aspects of the present invention to provide a dry powder inhaler device that deaggregates the powder without the need for a direct mechanical interface to transfer vibrations to a package containing the powder.

It is yet a further object of some aspects of the present invention to provide a dry powder inhaler device from which the powder is released during inhalation by a patient using of the device, without the need for an air flow sensor or other means of active synchronization with the patient's respiration.

It is still a further object of some aspects of the present invention to provide a multi-dose dry powder inhaler device, and Particularly such a device that allows convenient tracking of dosage and patient compliance.

In preferred embodiments of the present invention, a dry powder For delivery to a patient by inhalation is contained in a package having an opening through which the powder flows when the patient inhales. The powder is deaggregated and mobilized by application of a magnetic field. Preferably, the field interacts with the package, engendering rapid motion thereof, which deaggregates the powder.

According to an other aspect of the present invention, an electrostatic valve screen is created by means of an alternating electrostatic field in a vicinity of the opening, so as to trap particles of the powder and prevent their escape from the package except during inhalation.

In some preferred embodiments of the present invention, the alternating electrostatic field is applied using electrodes at either side of the opening. Only when air is made to flow through the opening at a rate above a given threshold, which is generally determined by the voltage applied between the electrodes, can the powder flow out through the electrostatic valve screen. The voltage is preferably set so that the flow rate passes the threshold when the patient inhales, whereby the powder is drawn out of the package and into the patient's lungs.

In some preferred embodiments of the present invention, the package comprises flexible side walls, which are made to vibrate by application of the magnetic field. The vibration of the walls deaggregates the powder in the package and generates air flow which suspends the powder in the air inside the package.

In some of these preferred embodiments, the side walls of the package are coupled to electrical wiring, preferably to coils in the form of electrical conductors applied to a surface of the walls in the manner of a flexible printed circuit. One or more permanent magnets apply a fixed magnetic field to the package. The coils on the walls of the package are driven by an alternating electrical current, generating a field that interacts with the fixed magnetic field and thus causes the walls to vibrate. Preferably, the walls comprise an array of coils, which are driven cooperatively to control the mode of vibration of the walls and thus regulate the air flow inside the package.

Preferably, the external magnetic field has a component in a direction perpendicular to a coil axis, in the plane of the coils, causing the walls to vibrate along the axis. Alternatively or additionally, the magnetic field has a component perpendicular to the plane of the coils, causing lateral vibrations.

In other preferred embodiments, the side walls of the package comprise a magnetic material, which is preferably coated on a surface of the walls. The magnetic field is applied by driving an electromagnet outside the package with an alternating current, which thus causes the walls to vibrate.

Preferably, the flexible side walls are made to vibrate at a resonant vibration frequency thereof, in order to maximize the vibrational energy. Most preferably, a frequency of the alternating current applied to the coils on the walls or to the electromagnet is set so as to engender the resonant vibration. In a preferred embodiment, the frequency of the alternating current is swept through a range of frequencies, preferably including the resonant frequency, and is then set at the Frequency that maximizes the effectiveness of deaggregation, which is typically the frequency that maximizes the wall vibration. For this purpose, a vibration sensor is preferably coupled to the wall and provides feedback for use in controlling the frequency of the alternating current. In another preferred embodiment, the vibration sensor is coupled in a positive feedback loon to a driver that provides the alternating current, causing the loop to spontaneously oscillate at or near the resonant frequency.

In still other preferred embodiments of the present invention, the powder particles comprise an electrically-or magnetically-active component, preferably in the form of a coating on or a compound in the particles. In some of these preferred embodiments, in which the particles are magnetically active, the application of the magnetic field deaggregates the particles without the necessity of vibrating the walls of the package. Preferably, the field is driven to alternate at or near a resonant motion frequency of the particles.

In other preferred embodiments, the electrically-active component enables charging of the particles with a low work function, by contact of the particles with a conductive area or the walls. The charged particles then interact with the electrostatic screen with enhanced efficiency.

In some preferred embodiments of the present invention, a powder inhaler device, operating as described hereinabove, comprises a disposable package, which is introduced into and actuated by a reusable control and power unit. Preferably, the package is a part of a multi-dose cartridge, which most preferably comprises multiple packets of the dry powder, which are actuated in succession. In a preferred embodiment, the control and power unit includes a dose counter, as well as an appropriate user interface, which informs and reminds a patient as to dosage to be administered. The dose counter can also be used to record patient dosage and compliance data to be read out subsequently by medical caregivers.

There is therefore provided, in accordance with a preferred embodiment of the present invention, an inhaler device for administration of a dry powder to a patient, including:

a package containing a dose of the dry powder; and

a magnetic field generator, which produces a magnetic field in a vicinity of the package, causing motion of particles of the powder so as to deaggregate the powder in the package, whereby the powder is inhaled by the patient.

Preferably, the package includes walls made of a flexible material, which vibrate under the influence of the magnetic field so as to impart the motion to the particles.

Further Preferably, the package includes electrical wiring coupled to at least one of the walls and a control unit which drives a time-varying current through the wiring, causing the walls to vibrate due to interaction of the current with the magnetic field. Most preferably, the wiring includes a circuit trace printed on at least one of the walls, which forms a plurality of coils. In a preferred embodiment, the control unit drives the plurality of coils at respective relative phases so as to induce a desired mode or vibration of the at least one of the walls.

Alternatively, the walls include a magnetic material, and the field generator includes an electromagnet, which produces a time-varying magnetic field, causing the walls to vibrate due to interaction of the magnetic material with the magnetic field. Preferably, the magnetic material includes a coating on the one or more of the walls.

In a preferred embodiment, the walls made of the flexible material include opposing side walls of the package, which vibrate in a controlled mutual phase relationship. Preferably, the opposing side walls are driven to vibrate in phase or alternatively, in mutually opposite phases so as to pump the powder out of the package.

Preferably, the walls are driven to vibrate at a frequency approximately equal to a resonant vibration frequency thereof. In a preferred embodiment, the device includes a driver circuit, which provides an alternating current of adjustable frequency to drive the vibration of the walls, and a vibration transducer coupled to one of the walls, which transducer provides feedback to the driver circuit, so that the frequency of the alternating current is adjusted such that the walls vibrate at approximately the resonant vibration frequency. Preferably, the driver circuit and transducer are arranged in a self-oscillating positive feedback loop.

In another preferred embodiment, the device includes a vibration sensor, which generates signals responsive to vibration of the walls, and a control unit, which receives the signals from the vibration sensor and, responsive thereto, controls the inhaler device so as to regulate an energy of vibration of the walls. Preferably, the control unit provides an alternating current of adjustable frequency to drive the vibration of the walls, and adjusts the frequency of the alternating current in order the maximize the energy of vibration.

In a preferred embodiment, the powder includes magnetized particles, and the field generator produces a time-varying magnetic field which interacts with magnetic fields of the particles, causing the particles to move. Preferably, a frequency of the time-varying magnetic field is adjusted so that the particles oscillate at appximatelly a resonant frequency thereof.

In still another preferred embodiment, the package includes a multi-dose cartridge, such that multiple doses of the dry powder are administered to the patient in succession, and the device includes a dose counter which tracks the administration of the doses.

There is further provided, in accordance with a preferred embodiment of the present invention, an inhaler device for administration of a dry powder to a patient, including:

a package containing a dose of the dry powder and having an opening through which the powder exits the package and is inhaled by the patient; and

an electrostatic valve screen, which traps the powder inside the package by generating a time-varying electrostatic field across the opening.

Preferably, the valve screen includes a pair of electrodes positioned on opposing sides of the opening.

Further preferably, the electrostatic valve screen allows the powder to pass through the opening when a rate of air flow through the opening exceeds a predetermined threshold, wherein the threshold is chosen such that inhalation by the patient generates an air flow through the opening in excess of the threshold.

Preferably, the electrostatic field causes particles of the powder to oscillate in a vicinity of the opening.

There is also provided, in accordance with a preferred embodiment of the present invention, a method for deaggregation of a dry powder for administration to a patient, including applying a magnetic field so as to cause motion of particles of the powder, whereby the powder is inhaled by the patient.

Preferably, the powder is contained in a package having walls made of a flexible material, and applying the magnetic field includes magnetically inducing vibration of the walls so as to impart the motion to the particles. Further preferably, inducing the vibration includes driving a time-varying current in wiring coupled to at least one of the walls, which current interacts with the magnetic field to induce the vibration of the walls. In a preferred embodiment, driving the current includes driving current in different portions of the wiring at respective, relative phases so as to induce a desired mode of vibration of the walls.

Alternatively, inducing the vibration includes applying a time-varying magnetic field, which interacts with magnetic material in the walls to induce the vibration.

In a preferred embodiment, inducing the vibration includes controlling relative phases of vibration of different ones of the walls.

In a further preferred embodiment, inducing the vibration includes driving the vibration at approximately a resonant vibration frequency of the walls. Preferably, inducing the vibration includes sensing vibration of one of the walls and adjusting a frequency of the vibration responsive to the sensing.

In still another preferred embodiment, the method includes magnetizing the particles, wherein applying the magnetic field includes applying a time-varying magnetic field which interacts with magnetic fields of the particles, causing the particles to move.

There is additionally provided, in accordance with a preferred embodiment of the present invention, a method for administration of a dry powder to a patient, including:

providing the dry powder in a package having an opening through which the powder exits the package and is inhaled by the patient; and

generating a time-varying electrostatic field across the opening so as to trap the powder inside the package until the patient inhales.

Preferably, generating the field includes adjusting the strength of the field so as to allow the powder to pass through the opening only when a rate of air flow through the opening exceeds a predetermined threshold, wherein the threshold is chosen such that inhalation by the patient generates an air flow through the opening in excess of the threshold.

Further preferably, generating the electrostatic field causes particles of the powder to oscillate in a vicinity of the opening.

Claim 1 of 36 Claims

What is claimed is:

1. An inhaler device for administration of a dry powder to a patient, comprising:

a package adapted to contain a dose of the dry powder; and

a magnetic field generator, operative to produce a magnetic field in a vicinity of the package, causing motion of particles of the powder so as to deaggregate the powder in the package, whereby the powder is inhaled by the patient,

wherein the package comprises walls made of a flexible material, which vibrate under the influence of the magnetic field so as to impart the motion to the particles,

the device further comprising electrical wiring coupled to at least one of the walls and a control unit coupled to drive a time-varying current through the wiring, causing the walls to vibrate due to interaction of the current with the magnetic field.

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