Note: Descriptions are shown in the official language in which they were submitted.
HOOKAH DEVICE
15
Field
The present invention relates to a hookah device. The present invention more
particularly relates to a hookah device which generates a mist using
ultrasonic
vibrations.
Background
The traditional hookah is a smoking device which bums tobacco leaves that
have been crushed and prepared specifically to be heated using charcoal. The
heat from the charcoal causes the crushed tobacco leaves to burn, producing
smoke that is pulled through water in a glass chamber and to the user by
inhalation. The water is used to cool the hot smoke for ease of inhalation.
Hookah use began centuries ago in ancient Persia and India. Today, hookah
cafés are gaining popularity around the world, including the United Kingdom,
France, Russia, the Middle East and the United States.
A typical modern hookah has a head (with holes in the bottom), a metal body, a
water bowl and a flexible hose with a mouthpiece. New forms of electronic
hookah products, including steam stones and hookah pens, have been
introduced. These products are battery or mains powered and heat liquid
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containing nicotine, flavorings and other chemicals to produce smoke which is
inhaled.
Although many users consider it less harmful than smoking cigarettes, hookah
smoking has many of the same health risks as cigarette smoking.
Thus, a need exists in the art for an improved hookah device which seeks to
address at least some of the problems described herein.
The present invention seeks to provide an improved hookah device.
Summary
According to some arrangements, there is provided a hookah device
comprising: a plurality of ultrasonic mist generator devices which are each
provided with a respective mist outlet port; a driver device which is
connected
electrically to each of the mist generator devices and configured to activate
the
mist generator devices; and a hookah attachment arrangement which is
configured to attach the hookah device to a hookah, the hookah attachment
arrangement having a hookah outlet port which provides a fluid flow path from
the mist outlet ports of the mist generator devices and out of the hookah
device
such that, when at least one of the mist generator devices is activated by the
driver device, mist generated by each activated mist generator device flows
along the fluid flow path and out of the hookah device to the hookah.
In some arrangements, the driver device is connected electrically to each of
the
mist generator devices by a data bus and the driver device is configured to
identify and control each mist generator device using a respective unique
identifier for the mist generator device.
In some arrangements, each mist generator device comprises: an identification
arrangement comprising: an integrated circuit having a memory which stores a
unique identifier for the mist generator device; and an electrical connection
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which provides an electronic interface for communication with the integrated
circuit.
In some arrangements, the driver device is configured to control each
respective mist generator device to activate independently of the other mist
generator devices.
In some arrangements, the driver device is configured to control the mist
generator devices to activate in a predetermined sequence.
In some arrangements, each mist generator device comprises: a manifold
having a manifold pipe which is in fluid communication with the mist outlet
ports
of the mist generator devices, wherein mist output from the mist outlet ports
combines in the manifold pipe and flows through the manifold pipe and out from
the hookah device.
In some arrangements, the hookah device comprises four mist generator
devices which are releasably coupled to the manifold at 90 relative to one
another.
In some arrangements, each mist generator device is releasably attached to
the driver device so that each mist generator device is separable from the
driver device.
In some arrangements, each mist generator device comprises: a mist generator
housing which is elongate and comprises an air inlet port and the said mist
outlet port; a liquid chamber provided within the mist generator housing, the
liquid chamber containing a liquid to be atomized; a sonication chamber
provided within the mist generator housing; a capillary element extending
between the liquid chamber and the sonication chamber such that a first
portion
of the capillary element is within the liquid chamber and a second portion of
the
capillary element is within the sonication chamber; an ultrasonic transducer
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having a generally planar atomization surface which is provided within the
sonication chamber, the ultrasonic transducer being mounted within the mist
generator housing such that the plane of the atomization surface is
substantially parallel with a longitudinal length of the mist generator
housing,
wherein part of the second portion of the capillary element is superimposed on
part of the atomization surface, and wherein the ultrasonic transducer is
configured to vibrate the atomization surface to atomize a liquid carried by
the
second portion of the capillary element to generate a mist comprising the
atomized liquid and air within the sonication chamber; and an airflow
arrangement which provides an air flow path between the air inlet port, the
sonication chamber and the air outlet port.
In some arrangements, each mist generator device further comprises: a
transducer holder which is held within the mist generator housing, wherein the
transducer element holds the ultrasonic transducer and retains the second
portion of the capillary element superimposed on part of the atomization
surface; and a divider portion which provides a barrier between the liquid
chamber and the sonication chamber, wherein the divider portion comprises a
capillary aperture through which part of the first portion of the capillary
element
extends.
In some arrangements, the capillary element is 100% bamboo fiber.
In some arrangements, the airflow arrangement is configured to change the
direction of a flow of air along the air flow path such that the flow of air
is
substantially perpendicular to the atomization surface of the ultrasonic
transducer as the flow of air passes into the sonication chamber.
In some arrangements, the liquid chamber contains a liquid having a kinematic
viscosity between 1.05 Pa's and 1.412 Pa's and a liquid density between 1.1
g/ml and 1.3 g/ml.
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In some arrangements, the liquid chamber contains a liquid comprising
approximately a 2:1 molar ratio of levulinic acid to nicotine.
In some arrangements, the driver device comprises: an AC driver which is
configured to generate an AC drive signal at a predetermined frequency to
drive a respective ultrasonic transducer in each mist generator device; an
active power monitoring arrangement which is configured to monitor the active
power used by the ultrasonic transducer when the ultrasonic transducer is
driven by the AC drive signal, wherein the active power monitoring
arrangement is configured to provide a monitoring signal which is indicative
of
an active power used by the ultrasonic transducer; a processor which is
configured to control the AC driver and to receive the monitoring signal drive
from the active power monitoring arrangement; and a memory storing
instructions which, when executed by the processor, cause the processor to:
A. control the AC driver to output an AC drive signal to the
ultrasonic transducer at a predetermined sweep frequency;
B. calculate the active power being used by the ultrasonic
transducer based on the monitoring signal;
C. control the AC driver to modulate the AC drive signal to
maximize the active power being used by the ultrasonic transducer;
D. store a record in the memory of the maximum active power
used by the ultrasonic transducer and the sweep frequency of the AC
drive signal;
E. repeat steps A-D for a predetermined number of iterations with
the sweep frequency incrementing with each iteration such that, after the
predetermined number of iterations has occurred, the sweep frequency
has been incremented from a start sweep frequency to an end sweep
frequency;
F. identify from the records stored in the memory the optimum
frequency for the AC drive signal which is the sweep frequency of the
AC drive signal at which a maximum active power is used by the
ultrasonic transducer; and
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G. control the AC driver to output an AC drive signal to the
ultrasonic transducer at the optimum frequency to drive the ultrasonic
transducer to atomize a liquid.
In some arrangements, the active power monitoring arrangement comprises: a
current sensing arrangement which is configured to sense a drive current of
the
AC drive signal driving the ultrasonic transducer, wherein the active power
monitoring arrangement is configured to provide a monitoring signal which is
indicative of the sensed drive current.
In some arrangements, the memory stores instructions which, when executed by
the processor, cause the processor to: repeat steps A-D with the sweep
frequency being incremented from a start sweep frequency of 2900kHz to an end
sweep frequency of 2960kHz.
In some arrangements, the memory stores instructions which, when executed by
the processor, cause the processor to: repeat steps A-D with the sweep
frequency being incremented from a start sweep frequency of 2900kHz to an end
sweep frequency of 3100kHz.
In some arrangements, the AC driver is configured to modulate the AC drive
signal by pulse width modulation to maximize the active power being used by
the
ultrasonic transducer.
According to some arrangements, there is provided a hookah comprising: a
water chamber; an elongate stem having a first end which is attached to the
water chamber, the stem comprising a mist flow path which extends from a
second end of the stem, through the stem, to the first end; and a hookah
device
according to any of the arrangements described above, wherein the hookah
attachment arrangement of the hookah device is attached to the stem of the
hookah at the second end of the stem.
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Brief description of the drawings
So that the present invention may be more readily understood, embodiments of
the present invention will now be described, by way of example, with reference
to the accompanying drawings, in which:
Figure 1 is an exploded view of components of an ultrasonic mist inhaler.
Figure 2 is an exploded view of components of an inhaler liquid reservoir
structure.
Figure 3 is a cross section view of components of an inhaler liquid reservoir
structure.
Figure 4A is an isometric view of an airflow member of the inhaler liquid
reservoir structure according to Figures 2 and 3.
Figure 4B is a cross section view of the airflow member shown in Figure 4A.
Figure 5 is schematic diagram showing a piezoelectric transducer modelled as
an RLC circuit.
Figure 6 is graph of frequency versus log impedance of an RLC circuit.
Figure 7 is graph of frequency versus log impedance showing inductive and
capacitive regions of operation of a piezoelectric transducer.
Figure 8 is flow diagram showing the operation of a frequency controller.
Figure 9 is a diagrammatic perspective view of a mist generator device of this
disclosure.
Figure 10 is a diagrammatic perspective view of a mist generator device of
this
disclosure.
Figure 11 is a diagrammatic exploded perspective view of a mist generator
device of this disclosure.
Figure 12 is a diagrammatic perspective view of a transducer holder of this
disclosure.
Figure 13 is a diagrammatic perspective view of a transducer holder of this
disclosure.
Figure 14 is a diagrammatic perspective view of a capillary element of this
disclosure.
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Figure 15 is a diagrammatic perspective view of a capillary element of this
disclosure.
Figure 16 is a diagrammatic perspective view of a transducer holder of this
disclosure.
Figure 17 is a diagrammatic perspective view of a transducer holder of this
disclosure.
Figure 18 is a diagrammatic perspective view of a part of a housing of this
disclosure.
Figure 19 is a diagrammatic perspective view of an absorbent element of this
disclosure.
Figure 20 is a diagrammatic perspective view of a part of a housing of this
disclosure.
Figure 21 is a diagrammatic perspective view of a part of a housing of this
disclosure.
Figure 22 is a diagrammatic perspective view of an absorbent element of this
disclosure.
Figure 23 is a diagrammatic perspective view of a part of a housing of this
disclosure.
Figure 24 is a diagrammatic perspective view of a part of a housing of this
disclosure.
Figure 25 is a diagrammatic perspective view of a part of a housing of this
disclosure.
Figure 26 is a diagrammatic perspective view of a circuit board of this
disclosure.
Figure 27 is a diagrammatic perspective view of a circuit board of this
disclosure.
Figure 28 is a diagrammatic exploded perspective view of a mist generator
device of this disclosure.
Figure 29 is a diagrammatic exploded perspective view of a mist generator
device of this disclosure.
Figure 30 is a cross sectional view of a mist generator device of this
disclosure.
Figure 31 is a cross sectional view of a mist generator device of this
disclosure.
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Figure 32 is a cross sectional view of a mist generator device of this
disclosure.
Figure 33 is a diagrammatic perspective view of a hookah device of this
disclosure.
Figure 34 is a diagrammatic perspective view of a hookah device of this
disclosure attached to a hookah body and water bowl of a hookah apparatus.
Figure 35 is a diagrammatic exploded perspective view of a hookah device of
this disclosure.
Figure 36 is a diagrammatic perspective view of components of a hookah
device of this disclosure.
Figure 37 is a diagrammatic perspective view of components of a hookah
device of this disclosure.
Figure 38 is a diagrammatic perspective view of a component of a hookah
device of this disclosure.
Figure 39 is a diagrammatic perspective view of a component of a hookah
device of this disclosure.
Figure 40 is a diagrammatic perspective view of a component of a hookah
device and four mist generator devices of this disclosure.
Figure 41 is a diagrammatic perspective view of components of a hookah
device of this disclosure.
Figure 42 is a diagrammatic cross-sectional view of components of a hookah
device of this disclosure.
Figure 43 is a diagrammatic perspective view of a hookah device of this
disclosure attached to a hookah body and water bowl of a hookah apparatus.
Detailed description
Aspects of the present disclosure are best understood from the following
detailed description when read with the accompanying figures. It is noted
that,
in accordance with the standard practice in the industry, various features are
not drawn to scale. In fact, the dimensions of the various features may be
arbitrarily increased or reduced for clarity of discussion.
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The following disclosure provides many different embodiments, or examples,
for implementing different features of the provided subject matter. Specific
examples of components, concentrations, applications and arrangements are
described below to simplify the present disclosure. These are, of course,
merely examples and are not intended to be limiting. For example, the
attachment of a first feature and a second feature in the description that
follows
may include embodiments in which the first feature and the second feature are
attached in direct contact, and may also include embodiments in which
additional features may be positioned between the first feature and the second
feature, such that the first feature and the second feature may not be in
direct
contact. In addition, the present disclosure may repeat reference numerals
and/or letters in the various examples. This repetition is for the purpose of
simplicity and clarity and does not in itself dictate a relationship between
the
various embodiments and/or configurations discussed.
The following disclosure describes representative arrangements or examples.
Each arrangement or example may be considered to be an embodiment and
any reference to an "arrangement" or an "example" may be changed to
"embodiment" in the present disclosure.
A hookah device of some arrangements incorporates ultrasonic aerosolization
technology. The hookah device of some arrangements is configured to replace
a conventional hookah head (coal-heated or electronically heated). The
hookah device of some arrangements releasably attaches to an existing stem
or metal body and water chamber/bowl in place of the conventional hookah
head which houses the tobacco and the charcoal (or electronic heating
element).
In other arrangements, the hookah device is provided with a stem/body and a
water chamber/bowl as a complete hookah apparatus.
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Hookah water bowls come in various shapes and sizes, ornamented with
traditional or futuristic decorations as per individual preferences. The
design
and development of the ultrasonic aerosolizing hookah device of some
arrangements was executed, keeping the tradition in mind, to create a
replaceable head that fits onto any existing hookah.
The following disclosure describes the components and functionality of an
ultrasonic mist generator device. The disclosure then describes the hookah
device of some arrangements which incorporates a plurality of ultrasonic mist
generator devices.
Conventional electronic vaporizing inhalers tend to rely on inducing high
temperatures of a metal component configured to heat a liquid in the inhaler,
thus vaporizing the liquid that can be breathed in. The liquid typically
contains
nicotine and flavorings blended into a solution of propylene glycol (PG) and
vegetable glycerin (VG), which is vaporized via a heating component at high
temperatures. Problems with conventional inhalers may include the possibility
of burning metal and subsequent breathing in of the metal along with the burnt
liquid. In addition, some may not prefer the burnt smell or taste caused by
the
heated liquid.
Figures 1 to 4 illustrate an ultrasonic mist inhaler comprising a sonication
chamber. It is noted that the expression "mist" used in the following
disclosure
means the liquid is not heated as usually in traditional inhalers known from
the
prior art. In fact, traditional inhalers use heating elements to heat the
liquid
above its boiling temperature to produce a vapor, which is different from a
mist.
When sonicating liquids at high intensities, the sound waves that propagate
into
the liquid media result in alternating high-pressure (compression) and low-
pressure (rarefaction) cycles, at different rates depending on the frequency.
During the low-pressure cycle, high-intensity ultrasonic waves create small
vacuum bubbles or voids in the liquid. This phenomenon is termed cavitation.
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When the bubbles attain a volume at which they can no longer absorb energy,
they collapse violently during a high-pressure cycle. During the implosion,
very
high pressures are reached locally. At cavitation, broken capillary waves are
generated, and tiny droplets break the surface tension of the liquid and are
quickly released into the air, taking mist form.
The following will explain more precisely the cavitation phenomenon.
When the liquid is atomized by ultrasonic vibrations, micro water bubbles are
produced in the liquid.
The bubble production is a process of formation of cavities created by the
negative pressure generated by intense ultrasonic waves generated by the
means of ultrasonic vibrations.
High intensity ultrasonic sound waves leading to rapid growth of cavities with
relatively low and negligible reduction in cavity size during the positive
pressure
cycle.
Ultrasound waves, like all sound waves, consist of cycles of compression and
expansion. When in contact with a liquid, Compression cycles exert a positive
pressure on the liquid, pushing the molecules together. Expansion cycles exert
a negative pressure, pulling the molecules away from another.
Intense ultrasound waves create regions of positive pressure and negative
pressure. A cavity can form and grow during the episodes of negative pressure.
When the cavity attains a critical size, the cavity implodes.
The amount of negative pressure needed depends on the type and purity of the
liquid. For truly pure liquids, tensile strengths are so great that available
ultrasound generators cannot produce enough negative pressure to make
cavities. In pure water, for instance, more than 1,000 atmospheres of negative
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pressure would be required, yet the most powerful ultrasound generators
produce only about 50 atmospheres of negative pressure. The tensile strength
of liquids is reduced by the gas trapped within the crevices of the liquid
particles. The effect is analogous to the reduction in strength that occurs
from
cracks in solid materials. When a crevice filled with gas is exposed to a
negative-pressure cycle from a sound wave, the reduced pressure makes the
gas in the crevice expand until a small bubble is released into solution.
However, a bubble irradiated with ultrasound continually absorbs energy from
alternating compression and expansion cycles of the sound wave. These cause
the bubbles to grow and contract, striking a dynamic balance between the void
inside the bubble and the liquid outside. In some cases, ultrasonic waves will
sustain a bubble that simply oscillates in size. In other cases, the average
size
of the bubble will increase.
Cavity growth depends on the intensity of sound. High-intensity ultrasound can
expand the cavity so rapidly during the negative-pressure cycle that the
cavity
never has a chance to shrink during the positive-pressure cycle. In this
process, cavities can grow rapidly in the course of a single cycle of sound.
For low-intensity ultrasound the size of the cavity oscillates in phase with
the
expansion and compression cycles. The surface of a cavity produced by low-
intensity ultrasound is slightly greater during expansion cycles than during
compression cycles. Since the amount of gas that diffuses in or out of the
cavity depends on the surface area, diffusion into the cavity during expansion
cycles will be slightly greater than diffusion out during compression cycles.
For
each cycle of sound, then, the cavity expands a little more than it shrinks.
Over
many cycles the cavities will grow slowly.
It has been noticed that the growing cavity can eventually reach a critical
size
where it will most efficiently absorb energy from the ultrasound. The critical
size
depends on the frequency of the ultrasound wave. Once a cavity has
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experienced a very rapid growth caused by high intensity ultrasound, it can no
longer absorb energy as efficiently from the sound waves. Without this energy
input the cavity can no longer sustain itself. The liquid rushes in and the
cavity
implodes due to a non-linear response.
The energy released from the implosion causes the liquid to be fragmented into
microscopic particles which are dispersed into the air as mist.
The equation for description of the above non-linear response phenomenon
may be described by the "Rayleigh-Plesset" equation. This equation can be
derived from the "Navier-Stokes" equation used in fluid dynamics.
The inventors approach was to rewrite the "Rayleigh-Plesset" equation in which
the bubble volume, V, is used as the dynamic parameter and where the physics
describing the dissipation is identical to that used in the more classical
form
where the radius is the dynamic parameter.
The equation used derived as follows:
1 6201
e2 8t2i ()
R 2
v20 T << 1
1
(17 2(0) = 1 47 \
Po + 20- 34v7ro) Pv Pv 2a( w) po ¨ P
(t)
4n A317) V 6V po
wherein:
V is the bubble volume
Vo is the equilibrium bubble volume
Po is the liquid density (assumed to be constant)
0 is the surface tension
Pv is the vapor pressure
p 0 is the static pressure in the liquid just outside the bubble wall
K is the polytropic index of the gas
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t is the time
R(t) is the bubble radius
P(t) is the applied pressure
c is the speed sound of the liquid
is the velocity potential
A is the wavelength of the insonifying field
In the ultrasonic mist inhaler, the liquid has a kinematic viscosity between
1.05
Pa.sec and 1.412 Pa.sec.
By solving the above equation with the right parameters of viscosity, density
and having a desired target bubble volume of liquid spray into the air, it has
been found that the frequency range of 2.8MHz to 3.2MHz for liquid viscosity
range of 1.05 Pa.s and 1.412 Pa.s produce a bubble volume of about 0.25 to
0.5 microns.
The process of ultrasonic cavitation has a significant impact on the nicotine
concentration in the produced mist.
No heating elements are involved, thereby leading to no burnt elements and
reducing second-hand smoke effects.
In some arrangements, said liquid comprises 57-70 % (w/w) vegetable glycerin
and 30-43% (w/w) propylene glycol, said propylene glycol including nicotine
and optionally flavorings.
In the ultrasonic mist inhaler, a capillary element may extend between the
sonication chamber and the liquid chamber.
In the ultrasonic mist inhaler, the capillary element is a material at least
partly in
bamboo fibers.
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The capillary element allows a high absorption capacity, a high rate of
absorption as well as a high fluid-retention ratio.
It was found that the inherent properties of the proposed material used for
the
capillarity have a significant impact on the efficient functioning of the
ultrasonic
mist inhaler.
Further, inherent properties of the proposed material include a good
hygroscopicity while maintaining a good permeability. This allows the drawn
liquid to efficiently permeate the capillary while the observed high
absorption
capacity allows the retention of a considerable amount of liquid thus allowing
the ultrasonic mist inhaler to last for a longer time when compared with the
other products available in the market.
Another significant advantage of using the bamboo fibers is the naturally
occurring antimicrobial bio-agent namely "Kun" inherently present within the
bamboo fiber making it antibacterial, anti-fungal and odor resistant, making
it
suitable for medical applications.
The inherent properties have been verified using numerical analysis regarding
the benefits of the bamboo fiber for son ication.
The following formulae have been tested with bamboo fibers material and
others material such cotton, paper, or other fiber strands for the use as
capillary
element and demonstrates that bamboo fibers have much better properties for
the use in sonication:
T 1
C = A + -n -1- (1 - a)¨
vvr
wherein:
C (cc/gm of fluid/gm) is the volume per mass of the liquid absorbed divided
by the dry mass of the capillary element,
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A (cm2) is the total surface area of the capillary element
T (cm) is the thickness of the capillary element,
WI (gm) is the mass of the dry capillary element,
Pir (cc/ g. sec) is the density of the dry capillary element,
a is the ratio of increase in volume of capillary element upon wetting to the
volume of liquid diffused in the capillary element,
V,/ (cc) is the amount of liquid diffused in the capillary element,
Trryl cos 0 ( T 1 \
Absorbent Rate,Q ¨
2r/ 1/17.r
Q (cc/sec) is the amount of liquid absorbed per unit time,
r (cm) is the radius of the pores within the capillary element,
y (N/m) is the surface tension of the liquid,
0 (degrees) is the angle of contact of the fiber,
(m2/sec) is the viscosity of the fluid.
Figure 1 depicts a disposable ultrasonic mist inhaler 100. As can be seen in
Figure 1, the ultrasonic mist inhaler 100 has a cylindrical body with a
relatively
long length as compared to the diameter. In terms of shape and appearance,
the ultrasonic mist inhaler 100 is designed to mimic the look of a typical
cigarette. For instance, the inhaler can feature a first portion 101 that
primarily
simulates the tobacco rod portion of a cigarette and a second portion 102 that
primarily simulates a filter. In the disposable arrangement, the first portion
and
second portion are regions of a single, but-separable device. The designation
of a first portion 101 and a second portion 102 is used to conveniently
differentiate the components that are primarily contained in each portion.
As can be seen in Figure 1, the ultrasonic mist inhaler comprises a mouthpiece
1, a liquid reservoir structure 2 and a casing 3. The first portion 101
comprises
the casing 3 and the second portion 102 comprises the mouthpiece 1 and the
reservoir structure 2.
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The first portion 101 contains the power supply energy.
An electrical storage device 30 powers the ultrasonic mist inhaler 100. The
electrical storage device 30 can be a battery, including but not limited to a
lithium-ion, alkaline, zinc-carbon, nickel-metal hydride, or nickel-cadmium
battery; a super capacitor; or a combination thereof. In the disposable
arrangement, the electrical storage device 30 is not rechargeable, but, in the
reusable arrangement, the electrical storage device 30 would be selected for
its
ability to recharge. In the disposable arrangement, the electrical storage
device
30 is primarily selected to deliver a constant voltage over the life of the
inhaler
100. Otherwise, the performance of the inhaler would degrade over time.
Preferred electrical storage devices that are able to provide a consistent
voltage output over the life of the device include lithium-ion and lithium
polymer
batteries.
The electrical storage device 30 has a first end 30a that generally
corresponds
to a positive terminal and a second end 30b that generally corresponds to a
negative terminal. The negative terminal is extending to the first end 30a.
Because the electrical storage device 30 is located in the first portion 101
and
the liquid reservoir structure 2 is located in the second portion 102, the
joint
needs to provide electrical communication between those components.
Electrical communication is established using at least an electrode or probe
that is compressed together when the first portion 101 is tightened into the
second portion 102.
In order for the device to be reusable, the electrical storage device 30 is
rechargeable. The casing 3 contains a charging port 32.
The integrated circuit 4 has a proximal end 4a and a distal end 4b. The
positive
terminal at the first end 30a of the electrical storage device 30 is in
electrical
communication with a positive lead of the flexible integrated circuit 4. The
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negative terminal at the second end 30b of the electrical storage device 30 is
in
electrical communication with a negative lead of the integrated circuit 4. The
distal end 4b of the integrated circuit 4 comprises a microprocessor. The
microprocessor is configured to process data from a sensor, to control a
light,
to direct current flow to means of ultrasonic vibrations 5 in the second
portion
102, and to terminate current flow after a pre-programnned amount of time.
The sensor detects when the ultrasonic mist inhaler 100 is in use (when the
user draws on the inhaler) and activates the microprocessor. The sensor can
be selected to detect changes in pressure, air flow, or vibration. In one
arrangement, the sensor is a pressure sensor. In the digital device, the
sensor
takes continuous readings which in turn requires the digital sensor to
continuously draw current, but the amount is small and overall battery life
would
be negligibly affected.
In some arrangements, the integrated circuit 4 comprises a H bridge, which
may be formed by 4 MOSFETs to convert a direct current into an alternate
current at high frequency.
Referring to Figure 2 and Figure 3, illustrations of a liquid reservoir
structure 2
according to an arrangement are shown. The liquid reservoir structure 2
comprises a liquid chamber 21 adapted to receive liquid to be atomized and a
sonication chamber 22 in fluid communication with the liquid chamber 21.
In the arrangement shown, the liquid reservoir structure 2 comprises an
inhalation channel 20 providing an air passage from the sonication chamber 22
toward the surroundings.
As an arrangement of sensor position, the sensor may be located in the
sonication chamber 22.
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The inhalation channel 20 has a frustoconical element 20a and an inner
container 20b.
As depicted in Figures 4A and 4B, further the inhalation channel 20 has an
airflow member 27 for providing air flow from the surroundings to the
sonication
chamber 22.
The airflow member 27 has an airflow bridge 27a and an airflow duct 27b made
in one piece, the airflow bridge 27a having two airway openings 27a' forming a
portion of the inhalation channel 20 and the airflow duct 27b extending in the
sonication chamber 22 from the airflow bridge 27a for providing the air flow
from the surroundings to the sonication chamber.
The airflow bridge 27a cooperates with the frustoconical element 20a at the
second diameter 20a2.
The airflow bridge 27a has two opposite peripheral openings 27a" providing air
flow to the airflow duct 27b.
The cooperation with the airflow bridge 27a and the frustoconical element 20a
is arranged so that the two opposite peripheral openings 27a" cooperate with
complementary openings 20a" in the frustoconical element 20a.
The mouthpiece 1 and the frustoconical element 20a are radially spaced and
an airflow chamber 28 is arranged between them.
As depicted in Figure 1 and 2, the mouthpiece 1 has two opposite peripheral
openings 1".
The peripheral openings 27a", 20a", 1" of the airflow bridge 27a, the
frustoconical element 20a and the mouthpiece 1 directly supply maximum air
flow to the sonication chamber 22.
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The frustoconical element 20a includes an internal passage, aligned in the
similar direction as the inhalation channel 20, having a first diameter 20a1
less
than that of a second diameter 20a2, such that the internal passage reduces in
diameter over the frustoconical element 20a.
The frustoconical element 20a is positioned in alignment with the means of
ultrasonic vibrations 5 and a capillary element 7, wherein the first diameter
20a1 is linked to an inner duct 11 of the mouthpiece 1 and the second diameter
20a2 is linked to the inner container 20b.
The inner container 20b has an inner wall delimiting the sonication chamber 22
and the liquid chamber 21.
The liquid reservoir structure 2 has an outer container 20c delimiting the
outer
wall of the liquid chamber 21.
The inner container 20b and the outer container 20c are respectively the inner
wall and the outer wall of the liquid chamber 21.
The liquid reservoir structure 2 is arranged between the mouthpiece 1 and the
casing 3 and is detachable from the mouthpiece 1 and the casing 3.
The liquid reservoir structure 2 and the mouthpiece 1 or the casing 3 may
include complimentary arrangements for engaging with one another; further
such complimentary arrangements may include one of the following: a bayonet
type arrangement; a threaded engaged type arrangement; a magnetic
arrangement; or a friction fit arrangement; wherein the liquid reservoir
structure
2 includes a portion of the arrangement and the mouthpiece 1 or the casing 3
includes the complimentary portion of the arrangement.
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In the reusable arrangement, the components are substantially the same. The
differences in the reusable arrangement vis-a-vis the disposable arrangement
are the accommodations made to replace the liquid reservoir structure 2.
As shown in Figure 3, the liquid chamber 21 has a top wall 23 and a bottom
wall 25 closing the inner container 20b and the outer container 20c of the
liquid
chamber 21.
The capillary element 7 is arranged between a first section 20b1 and a second
section 20b2 of the inner container 20b.
The capillary element 7 has a flat shape extending from the sonication chamber
to the liquid chamber.
As depicted in Figure 2 or 3, the capillary element 7 comprises a central
portion
7a in U-shape and a peripheral portion 7b in L-shape.
The [-shape portion 7b extends into the liquid chamber 21 on the inner
container 20b and along the bottom wall 25.
The U-shape portion 7a is contained into the sonication chamber 21. The U-
shape portion 7a on the inner container 20b and along the bottom wall 25.
In the ultrasonic mist inhaler, the U-shape portion 7a has an inner portion
7a1
and an outer portion 7a2, the inner portion 7a1 being in surface contact with
an
atomization surface 50 of the means of ultrasonic vibrations 5 and the outer
portion 7a2 being not in surface contact with the means of ultrasonic
vibrations
5.
The bottom wall 25 of the liquid chamber 21 is a bottom plate 25 closing the
liquid chamber 21 and the sonication chamber 22. The bottom plate 25 is
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sealed, thus preventing leakage of liquid from the sonication chamber 22 to
the
casing 3.
The bottom plate 25 has an upper surface 25a having a recess 25b on which is
inserted an elastic member 8. The means of ultrasonic vibrations 5 are
supported by the elastic member 8. The elastic member 8 is formed from an
annular plate-shaped rubber having an inner hole 8' wherein a groove is
designed for maintaining the means of ultrasonic vibrations 5.
The top wall 23 of the liquid chamber 21 is a cap 23 closing the liquid
chamber
23.
The top wall 23 has a top surface 23 representing the maximum level of the
liquid that the liquid chamber 21 may contain and the bottom surface 25
representing the minimum level of the liquid in the liquid chamber 21.
The top wall 23 is sealed, thus preventing leakage of liquid from the liquid
chamber 21 to the mouthpiece 1.
The top wall 23 and the bottom wall 25 are fixed to the liquid reservoir
structure
2 by means of fixation such as screws, glue or friction.
As depicted in Figure 3, the elastic member is in line contact with the means
of
ultrasonic vibrations 5 and prevents contact between the means of ultrasonic
vibrations 5 and the inhaler walls, suppression of vibrations of the liquid
reservoir structure are more effectively prevented. Thus, fine particles of
the
liquid atomized by the atomizing member can be sprayed farther.
As depicted in Figure 3, the inner container 20b has openings 20b' between the
first section 20b1 and the second section 20b2 from which the capillary
element
7 is extending from the sonication chamber 21. The capillary element 7 absorbs
liquid from the liquid chamber 21 through the apertures 20b'. The capillary
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element 7 is a wick. The capillary element 7 transports liquid to the
sonication
chamber 22 via capillary action. In some arrangements, the capillary element 7
is made of bamboo fibers. In some arrangements, the capillary element 7 may
be of a thickness between 0.27mm and 0.32mm and have a density between
38 g/m2 and 48 g/m2.
As can be seen in Figure 3, the means of ultrasonic vibrations 5 are disposed
directly below the capillary element 7.
The means of ultrasonic vibrations 5 may be an ultrasonic transducer. For
arrangement, the means of ultrasonic vibrations 5 may be a piezoelectric
transducer, which may be designed in a circular plate-shape. The material of
the piezoelectric transducer may be ceramic.
A variety of transducer materials can also be used for the means of ultrasonic
vibrations 5.
The end of the airflow duct 27b1 faces the means of ultrasonic vibrations 5.
The means of ultrasonic vibrations 5 are in electrical communication with
electrical contactors 101a, 101b. It is noted that, the distal end 4b of the
integrated circuit 4 has an inner electrode and an outer electrode. The inner
electrode contacts the first electrical contact 101a which is a spring contact
probe, and the outer electrode contacts the second electrical contact 101b
which is a side pin. Via the integrated circuit 4, the first electrical
contact 101a
is in electrical communication with the positive terminal of the electrical
storage
device 30 by way of the microprocessor, while the second electrical contact
101b is in electrical communication with the negative terminal of the
electrical
storage device 30.
The electrical contacts 101a, 101b crossed the bottom plate 25. The bottom
plate 25 is designed to be received inside the perimeter wall 26 of the liquid
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reservoir structure 2. The bottom plate 25 rests on complementary ridges,
thereby creating the liquid chamber 21 and sonication chamber 22.
The inner container 20b comprises a circular inner slot 20d on which a
mechanical spring is applied.
By pushing the central portion 7a1 onto the means of ultrasonic vibrations 5,
the mechanical spring 9 ensures a contact surface between them.
The liquid reservoir structure 2 and the bottom plate 25 can be made using a
variety of thermoplastic materials.
When the user draws on the ultrasonic mist inhaler 100, an air flow is drawn
from the peripheral openings 1" and penetrates the airflow chamber 28, passes
the peripheral openings 27a" of the airflow bridge 27a and the frustoconical
element 20a and flows down into the sonication chamber 22 via the airflow duct
27b directly onto the capillary element 7. At the same time, the liquid is
drawn
from the reservoir chamber 21 by capillarity, through the plurality of
apertures
20b', and into the capillary element 7. The capillary element 7 brings the
liquid
into contact with the means of ultrasonic vibrations 5 of the inhaler 100. The
user's draw also causes the pressure sensor to activate the integrated circuit
4,
which directs current to the means of ultrasonic vibrations 5. Thus, when the
user draws on the mouthpiece 1 of the inhaler 100, two actions happen at the
same time. Firstly, the sensor activates the integrated circuit 4, which
triggers
the means of ultrasonic vibrations 5 to begin vibrating. Secondly, the draw
reduces the pressure outside the reservoir chamber 21 such that flow of the
liquid through the apertures 20b' begins, which saturates the capillary
element
7. The capillary element 7 transports the liquid to the means of ultrasonic
vibrations 5, which causes bubbles to form in a capillary channel by the means
of ultrasonic vibrations 5 and mist the liquid. Then, the mist liquid is drawn
by
the user.
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In some arrangements, the integrated circuit 4 comprises a frequency
controller
which is configured to control the frequency at which the means of ultrasonic
vibrations 5 operates. The frequency controller comprises a processor and a
memory, the memory storing executable instructions which, when executed by
the processor, cause the processor to perform at least one function of the
frequency controller.
As described above, in some arrangements the ultrasonic mist inhaler 100
drives the means of ultrasonic vibrations 5 with a signal having a frequency
of
2.8MHz to 3.2MHz in order to vaporize a liquid having a liquid viscosity of
1.05
Pa.s to 1.412 Pa.s in order to produce a bubble volume of about 0.25 to 0.5
microns. However, for liquids with a different viscosity or for other
applications
it the means of ultrasonic vibrations 5 may be driven at a different
frequency.
For each different application for a mist generation system, there is an
optimum
frequency or frequency range for driving the means of ultrasonic vibrations 5
in
order to optimize the generation of mist. In arrangements where the means of
ultrasonic vibrations 5 is a piezoelectric transducer, the optimum frequency
or
frequency range will depend on at least the following four parameters:
1. Transducer Manufacturing Processes
In some arrangements, the means of ultrasonic vibrations 5 comprises a
piezoelectric ceramic. The piezoelectric ceramic is manufactured by mixing
compounds to make a ceramic dough and this mixing process may not be
consistent throughout production. This inconsistency can give rise to a range
of different resonant frequencies of the cured piezoelectric ceramic.
If the resonant frequency of the piezoelectric ceramic does not correspond to
the required frequency of operation of the device then no mist is produced
during the operation of the device. In the case of a nicotine mist inhaler,
even a
slight offset in the resonant frequency of the piezoelectric ceramic is enough
to
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impact the production of mist, meaning that the device will not deliver
adequate
nicotine levels to the user.
2. Load on transducer
During operation, any changes in the load on the piezoelectric transducer will
inhibit the overall displacement of the oscillation of the piezoelectric
transducer.
To achieve optimal displacement of the oscillation of the piezoelectric
transducer, the drive frequency must be adjusted to enable the circuit to
provide adequate power for maximum displacement.
The types of loads that can affect the oscillator's efficiency can include the
amount of liquid on the transducer (dampness of the wicking material), and the
spring force applied to the wicking material to keep permanent contact with
the
transducer. It may also include the means of electrical connection.
3. Temperature
Ultrasonic oscillations of the piezoelectric transducer are partially damped
by its
assembly in a device. This may include the transducer being placed in a
silicone/rubber ring, and the spring exerting pressure onto the wicking
material
that is above the transducer. This dampening of the oscillations causes rise
in
local temperatures on and around the transducer.
An increase in temperature affects the oscillation due to changes in the
molecular behavior of the transducer. An increase in the temperature means
more energy to the molecules of the ceramic, which temporarily affects its
crystalline structure. Although the effect is reversed as the temperature
reduces, a modulation in supplied frequency is required to maintain optimal
oscillation.
This modulation of frequency cannot be achieved with a
conventional fixed frequency device.
An increase in temperature also reduces the viscosity of the solution (e-
liquid)
which is being vaporized, which may require an alteration to the drive
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frequency to induce cavitation and maintain continuous mist production. In the
case of a conventional fixed frequency device, a reduction in the viscosity of
the liquid without any change in the drive frequency will reduce or completely
stop mist production, rendering the device inoperable.
4. Distance to Power Source
The oscillation frequency of the electronic circuit can change depending on
the
wire-lengths between the transducer and the oscillator-driver. The frequency
of
the electronic circuit is inversely proportional to the distance between the
transducer and the remaining circuit.
Although the distance parameter is primarily fixed in a device, it can vary
during
the manufacturing process of the device, reducing the overall efficiency of
the
device. Therefore, it is desirable to modify the drive frequency of the device
to
compensate for the variations and optimize the efficiency of the device.
A piezoelectric transducer can be modelled as an RLC circuit in an electronic
circuit, as shown in Figure 5. The four parameters described above may be
modelled as alterations to the overall inductance, capacitance, and/or
resistance of the RLC circuit, changing the resonance frequency range
supplied to the transducer. As the frequency of the circuit increases to
around
the resonance point of the transducer, the log Impedance of the overall
circuit
dips to a minimum and then rises to a maximum before settling to a median
range.
Figure 6 shows a generic graph explaining the change in overall impedance
with increase in frequency in an RLC circuit. Figure 7 shows how a
piezoelectric transducer acts as a capacitor in a first capacitive region at
frequencies below a first predetermined frequency fs and in a second
capacitive
region at frequencies above a second predetermined frequency fp. The
piezoelectric transducer acts as an inductor in an inductive region at
frequencies between the first and second predetermined frequencies fs, fp. In
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order to maintain optimal oscillation of the transducer and hence maximum
efficiency, the current flowing through the transducer must be maintained at a
frequency within the inductive region.
The frequency controller of the device of some arrangements is configured to
maintain the frequency of oscillation of the piezoelectric transducer (the
means
of ultrasonic vibrations 5) within the inductive region, in order to maximize
the
efficiency of the device.
The frequency controller is configured to perform a sweep operation in which
the frequency controller drives the transducer at frequencies which track
progressively across a predetermined sweep frequency range. As the
frequency controller performs the sweep, the frequency controller monitors an
Analog-to-Digital Conversion (ADC) value of an Analog-to-Digital converter
which is coupled to the transducer. In some arrangements the ADC value is a
parameter of the ADC which is proportional to the voltage across the
transducer. In other arrangements, the ADC value is a parameter of the ADC
which is proportional to the current flowing through the transducer.
As will be described in more detail below, the frequency controller of some
arrangements determines the active power being used by the ultrasonic
transducer by monitoring the current flowing through the transducer.
During the sweep operation, the frequency controller locates the inductive
region of the frequency for the transducer. Once the frequency controller has
identified the inductive region, the frequency controller records the ADC
value
and locks the drive frequency of the transducer at a frequency within the
inductive region (i.e. between the first and second predetermined frequencies
f5, fp) in order to optimize the ultrasonic cavitation by the transducer. When
the
drive frequency is locked within the inductive region, the electro-mechanical
coupling factor of the transducer is maximized, thereby maximizing the
efficiency of the device.
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In some arrangements, the frequency controller is configured to perform the
sweep operation to locate the inductive region each time the oscillation is
started or re-started.
In the arrangements, the frequency controller is
configured to lock the drive frequency at a new frequency within the inductive
region each time the oscillation is started and thereby compensate for any
changes in the parameters that affect the efficiency of operation of the
device.
In some arrangements, the frequency controller ensures optimal mist
production and maximizes efficiency of medication delivery to the user. In
some arrangements, the frequency controller optimizes the device and
improves the efficiency and maximizes nicotine delivery to the user.
In other arrangements, the frequency controller optimizes the device and
improves the efficiency of any other device which uses ultrasound. In some
arrangements, the frequency controller is configured for use with ultrasound
technology for therapeutic applications in order to extend the enhancement of
drug release from an ultrasound-responsive drug delivery system. Having
precise, optimal frequency during operation, ensures that the microbubbles,
nanobubbles, nanodroplets, liposome, emulsions, micelles or any other delivery
systems are highly effective.
In some arrangements, in order to ensure optimal mist generation and optimal
delivery of compounds as described above, the frequency controller is
configured to operate in a recursive mode. When the frequency controller
operates in the recursive mode, the frequency controller runs the sweep of
frequencies periodically during the operation of the device and monitors the
ADC value to determine if the ADC value is above a predetermined threshold
which is indicative of optimal oscillation of the transducer.
In some arrangements, the frequency controller runs the sweep operation while
the device is in the process of aerosolizing liquid in case the frequency
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controller is able to identify a possible better frequency for the transducer.
If
the frequency controller identifies a better frequency, the frequency
controller
locks the drive frequency at the newly identified better frequency in order to
maintain optimal operation of the device.
In some arrangements, the frequency controller runs the sweep of frequencies
for a predetermined duration periodically during the operation of the device.
In
the case of the device of the arrangements described above, the
predetermined duration of the sweep and the time period between sweeps are
selected to optimize the functionality of the device. When implemented in an
ultrasonic mist inhaler device, this will ensure an optimum delivery to a user
throughout the user's inhalation.
Figure 8 shows a flow diagram of the operation of the frequency controller of
some arrangements.
The following disclosure discloses further arrangements of mist generator
devices which comprise many of the same elements as the arrangements
described above. Elements of the arrangements described above may be
interchanged with any of the elements of the arrangements described in the
remaining part of this disclosure.
The mist generator devices described below are used with or are for use with a
hookah device 202 which is also described below. In other arrangements, the
hookah device 202 comprises a plurality of other mist generator devices
instead of the mist generator device 201 described herein.
To ensure adequate aerosol production, the mist generator device 201 of some
arrangements comprises an ultrasonic/piezoelectric transducer of exactly or
substantially 16mm diameter. This transducer is manufactured to specific
capacitance and impedance values to control the frequency and power
required for desired aerosol volume production.
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A horizontally placed disc-shaped 16mm diameter ultrasonic transducer would
result in a large mist generator device. To minimize the size, the ultrasonic
transducer of this arrangement is held vertically in the sonication chamber
(the
planar surface of the ultrasonic transducer is generally parallel with the
flow of
aerosol mist and/or generally parallel to the longitudinal length of the mist
generator device). Put another way, the ultrasonic transducer is generally
perpendicular to a base of the mist generator device.
Referring now to Figures 9 to 11 of the accompanying drawings, the mist
generator device 201 comprises a mist generator housing 204 which is
elongate and optionally formed from two housing portions 205, 206 which are
attached to one another. The mist generator housing 204 comprises an air
inlet port 207 and a mist outlet port 208.
In this arrangement, the mist generator housing 204 is of injection molded
plastic, specifically polypropylene that is typically used for medical
applications.
In this arrangement, the mist generator housing 204 is of a heterophasic
copolymer. More particularly a BF970M0 heterophasic copolymer, which has
an optimum combination of very high stiffness and high impact strength. The
mist generator housing parts molded with this material exhibit good anti-
static
performance.
A heterophasic copolymer such as polypropylene is particularly suitable for
the
mist generator housing 204 since this material does not cause condensation of
the aerosol as it flows from the sonication chamber 219 through the mist
outlet
port 208. This plastic material can also be directly recycled easily using
industrial shredding and cleaning processes.
In Figure 10, the mist outlet port 208 is closed by a closure element 209.
However, it is to be appreciated that when the mist inhaler device 200 is in
use,
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the closure element 209 is removed from the mist outlet port 208, as shown in
Figure 9.
Referring now to Figures 12 and 13, the mist generator device 200 comprises a
transducer holder 210 which is held within the mist generator housing 204. The
transducer holder 210 comprises a body portion 211 which, in this
arrangement, is cylindrical or generally cylindrical in shape with circular
upper
and lower openings 212, 213. The transducer holder 210 is provided with an
internal channel 214 for receiving an edge of an ultrasonic transducer 215, as
shown in Figure 13.
The transducer holder 210 incorporates a cutaway section 216 through which
an electrode 217 extends from the ultrasonic transducer 215 so that the
electrode 217 may be connected electrically to an AC driver of the hookah
device 202, as described in more detail below.
Referring again to Figure 11, the mist generator device 201 comprises a liquid
chamber 218 which is provided within the mist generator housing 204. The
liquid chamber 218 is for containing a liquid to be atomized. In some
arrangements, a liquid is contained in the liquid chamber 218. In other
arrangements, the liquid chamber 218 is empty initially and the liquid chamber
is filled with a liquid subsequently.
A liquid (also referred to herein as an e-liquid) composition suitable for use
in
an ultrasonic mist generator device 201 of some arrangements consists of a
nicotine salt consisting of nicotine levulinate wherein:
The relative amount of vegetable glycerin in the composition is: from 55 to
80%
(w/w), or from 60 to BO% (w/w), or from 65 to 75% (w/w), or 70% (w/w); and/or,
The relative amount of propylene glycol in the composition is: from 5 to 30%
(w/w), or from 10 to 30% (w/w), or from 15 to 25% (w/w), or 20% (w/w); and/or,
The relative amount of water in the composition is: from 5 to 15% (w/w), or
from
7 to 12% (w/w), or 10% (w/w); and/or,
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The amount of nicotine and/or nicotine salt in the composition is: from 0.1 to
80
mg/ml, or from 0.1 to 50 mg/ml, or from Ito 25 mg/ml, or from 10 to 20 mg/ml,
or 17 mg/ml.
In some arrangements, the mist generator device 201 contains an e-liquid
having a kinematic viscosity between 1.05 Paws and 1.412 Pails.
In some arrangements, the liquid chamber 218 contains a liquid comprising a
nicotine levulinate salt at a 1:1 molar ratio.
In some arrangements, the liquid chamber 218 contains an e-liquid comprising
nicotine, propylene glycol, vegetable glycerin, water and flavorings. In some
examples, the A concentration of each component in the e-liquid is shown
below in Table 1, Table 2, Table 3 or Table 4.
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Table 1: The % concentration of each component in the e-liquid (e-liquid 1).
Component % (w/w)
Propylene glycol 15.1
Vegetable glycerin 70
Water 10
Nicotine 1.7
Levulinic acid 0.2
Flavorings 3
Table 2: The % concentration of each component in the e-liquid (e-liquid 2).
(Approximately, 2:1 molar ratio of levulinic acid to nicotine.)
Component % (w/w)
Propylene glycol 12.87
Vegetable glycerin 70
Water 10
Nicotine 1.7
Levulinic acid 2.43
Flavorings 3
Table 3: The % concentration of each component in the e-liquid (e-liquid 3).
(Approximately, 1:1 molar ratio of levulinic acid to nicotine.)
Component % (w/w)
Propylene glycol 14.08
Vegetable glycerin 70
Water 10
Nicotine 1.7
Levulinic acid 1.22
Flavorings 3
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Table 4: The % concentration of each component in the e-liquid (e-liquid 4).
(Approximately, 3:1 molar ratio of levulinic acid to nicotine.)
Component % (w/w)
Propylene glycol 11.64
Vegetable glycerin 70
Water 10
Nicotine 1.7
Levulinic acid 3.66
Flavorings 3
In the non-limiting examples, the nicotine in solution is all or part in the
form of
nicotine levulinate.
The nicotine levulinate salt is formed by combining nicotine and levulinic
acid in
solution. This results in the formation of the salt nicotine levulinate, which
comprises a levulinate anion and a nicotine cation.
The % concentration of nicotine in the e-liquid shown in Table 1, Table 2,
Table
3 and Table 4 is approximately equivalent to 17 mg/ml.
In some arrangements, the liquid chamber 218 contains a liquid having a
kinematic viscosity between 1.05 Pa.s and 1.412 Pa.s and a liquid density
between 1.1 g/m1 and 1.3 g/ml.
In some arrangements, the liquid within the liquid chamber 218 comprises a
flavoring (e.g. a fruit flavor) which is tasted by a user when the user
inhales
mist generated by the hookah device.
By using an e-liquid with the correct parameters of viscosity, density and
having
a desired target bubble volume of liquid spray into the air, it has been found
that the frequency range of 2.8MHz to 3.2MHz for liquid viscosity range of
1.05
Pa=s and 1.412 Pa=s and density of approximately 1.1-1.3 g/mL (get density
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ranges from Hertz) produce a droplet volume where 90% of droplets are below
1 micron and 50% of those are less than 0.5 microns.
The mist generator device 201 comprises a sonication chamber 219 which is
provided within the mist generator housing 204.
Returning to Figures 12 and 13, the transducer holder 210 comprises a divider
portion 220 which provides a barrier between the liquid chamber 218 and the
sonication chamber 219. The barrier provided by the divider portion 220
minimizes the risk of the sonication chamber 219 being is flooded with liquid
from the liquid chamber 218 or for a capillary element over the ultrasonic
transducer 215 becoming oversaturated, either of which would overload and
reduce the efficiency of the ultrasonic transducer 215. Moreover, flooding the
sonication chamber 219 or over saturating the capillary element could also
cause an unpleasant experience with the liquid being sucked in by the user
during inhalation. To mitigate this risk, the divider portion 220 of the
transducer
holder 210 sits as a wall between the sonication chamber 219 and the liquid
chamber 218.
The divider portion 220 comprises a capillary aperture 221 which is the only
means by which liquid can flow from the liquid chamber 218 to the sonication
chamber 219, via a capillary element. In this arrangement, the capillary
aperture 221 is an elongate slot having a width of 0.2mm to 0.4mm. The
dimensions of the capillary aperture 221 are such that the edges of the
capillary
aperture 221 provide a biasing force which acts on a capillary element
extending through the capillary aperture 221 for added control of liquid flow
to
the sonication chamber 219.
In this arrangement, the transducer holder 210 is of liquid silicone rubber
(LSR). In this arrangement, the liquid silicone rubber has a Shore A 60
hardness. This LSR material ensures that the ultrasonic transducer 215
vibrates without the transducer holder 210 dampening the vibrations. In this
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arrangement, the vibratory displacement of the ultrasonic transducer 215 is 2-
5
nanometers and any dampening effect may reduce the efficiency of the
ultrasonic transducer 215. Hence, this [SR material and hardness is selected
for optimal performance with minimal compromise.
Referring now to Figures 14 and 15, the mist generator device 201 comprises a
capillary or capillary element 222 for transferring a liquid (containing a
drug or
other substance) from the liquid chamber 218 to the sonication chamber 219.
The capillary element 222 is planar or generally planar with a first portion
223
and a second portion 224. In this arrangement, the first portion 223 has a
rectangular or generally rectangular shape and the second portion 224 has a
partly circular shape.
In this arrangement, the capillary element 222 comprises a third portion 225
and a fourth portion 226 which are respectively identical in shape to the
first
and second portions 223, 224. The capillary element 222 of this arrangement
is folded about a fold line 227 such that the first and second portions 223,
224
and the third and fourth portions 225, 226 are superimposed on one another,
as shown in Figure 15.
In this arrangement, the capillary element has a thickness of approximately
0.28mm. When the capillary element 222 is folded to have two layers, as
shown in Figure 15, the overall thickness of the capillary element is
approximately 0.56mm. This double layer also ensures that there is always
sufficient liquid on the ultrasonic transducer 215 for optimal aerosol
production.
In this arrangement, when the capillary element 222 is folded, the lower end
of
the first and third parts 223, 225 defines an enlarged lower end 228 which
increases the surface area of the capillary element 222 in the portion of the
capillary element 222 which sits in liquid within the liquid chamber 218 to
maximize the rate at which the capillary element 222 absorbs liquid.
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In this arrangement, the capillary element 222 is 100% bamboo fiber. In other
arrangements, the capillary element is of at least 75% bamboo fiber. The
benefits of using bamboo fiber as the capillary element are as described
above.
Referring now to Figures 16 and 17, the capillary element 222 is retained by
the transducer holder 210 such that the transducer holder 210 retains the
second portion 224 of the capillary element 222 superimposed on part of an
atomization surface of the ultrasonic transducer 215. In this arrangement, the
circular second portion 224 sits within the inner recess 214 of the transducer
holder 210.
The first portion 223 of the capillary element 222 extends through the
capillary
aperture 221 in the transducer holder 210.
Referring now to Figures 18 to 20, the second portion 206 of the mist
generator
housing 204 comprises a generally circular wall 229 which receives the
transducer holder 222 and forms part of the wall of the sonication chamber
219.
Contact apertures 230 and 231 are provided in a side wall of the second
portion 206 for receiving electrical contacts 232 and 233 which form
electrical
connections with the electrodes of the ultrasonic transducer 215.
In this arrangement, an absorbent tip or absorbent element 234 is provided
adjacent the mist outlet port 208 to absorb liquid at the mist outlet port
208. In
this arrangement, the absorbent element 234 is of bamboo fiber.
Referring now to Figures 21 to 23, the first portion 205 of the mist generator
housing 204 is of a similar shape to the second portion 206 and comprises a
further generally circular wall portion 235 which forms a further portion of
the
wall of the sonication chamber 219 and retains the transducer holder 210.
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In this arrangement, a further absorbent element 236 is provided adjacent the
mist outlet port 208 to absorb liquid at the mist outlet port 208.
In this arrangement, the first portion 205 of the mist generator housing 204
comprises a spring support arrangement 237 which supports the lower end of a
retainer spring 238, as shown in Figure 24.
An upper end of the retainer spring 238 contacts the second portion 224 of the
capillary element 222 such that the retainer spring 238 provides a biasing
force
which biases the capillary element 222 against the atomization surface of the
ultrasonic transducer 215.
Referring to Figure 25, the transducer holder 210 is shown in position and
being retained by the second portion 206 of the mist generator housing 204,
prior to the two portions 205, 206 of the mist generator housing 204 being
attached to one another.
Referring to Figures 26 to 29, in this arrangement, the mist generator device
201 comprises an identification arrangement 239.
The identification
arrangement 239 comprises a printed circuit board 240 having electrical
contacts 241 provided on one side and an integrated circuit 242 and another
optional component 243 provided on the other side.
The integrated circuit 242 has a memory which stores a unique identifier for
the
mist generator device 201. The electrical contacts 241 provide an electronic
interface for communication with the integrated circuit 242.
The printed circuit board 240 is, in this arrangement, mounted within a recess
244 on one side of the mist generator housing 204. The integrated circuit 242
and optional other electronic components 243 sit within a further recess 245
so
that the printed circuit board 240 is generally flush with the side of the
mist
generator housing 204.
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In this arrangement, the integrated circuit 242 is a one-time-programmable
(OTP) device which provides an anti-counterfeiting feature that allows only
genuine mist generator devices from the manufacturer to be used with the
device. This anti-counterfeiting feature is implemented in the mist generator
device 201 as a specific custom integrated circuit (IC) that is bonded (with
the
printed circuit board 240) to the mist generator device 201. The OTP as IC
contains a truly unique information that allows a complete traceability of the
mist generator device 201 (and its content) over its lifetime as well as a
precise
monitoring of the consumption by the user. The OTP IC allows the mist
generator device 201 to function to generate mist only when authorized.
The OTP, as a feature, dictates the authorized status of a specific mist
generator device 201. Indeed, in order to prevent emissions of carbonyls and
keep the aerosol at safe standards, experiments have shown that the mist
generator device 201 is considered empty of liquid in the liquid chamber 218
after approximately 1,000 seconds of aerosolization. In that way a mist
generator device 201 that is not genuine or empty will not be able to be
activated after this predetermined duration of use.
The OTP, as a feature, may be part of a complete chain with the conjunction of
the digital sale point, the mobile companion application and the mist
generator
device 201. Only a genuine mist generator device 201 manufactured by a
trusted party and sold on the digital sale point can be used in the hookah
device 202. The OTP IC is read by the hookah device 202 which recognizes
the mist generator device 201.
In some arrangements, the OTP IC is disposable in the same way as the mist
generator device 201. Whenever the mist generator device 201 is considered
empty, it will not be activated if inserted into a hookah device 202.
Similarly, a
counterfeit mist generator device 201 would not be functional in the hookah
device 202.
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Figures 30 to 32 illustrate how air flows through the mist generator device
201
during operation.
The sonication of the liquid drug (e.g. nicotine) transforms it into mist
(aerosolization). However, this mist would settle over the ultrasonic
transducer
215 unless enough ambient air is available to replace the rising aerosol. In
the
sonication chamber 219, there is a requirement for a continuous supply of air
as mist (aerosol) is generated and pulled out through the mist outlet port
208.
To cater to this requirement, an airflow channel is provided. In this
arrangement
the airflow channel has an average cross-sectional area of 11.5mm2, which is
calculated and designed into the sonication chamber 219 based on the
negative air pressure from an average user. This also controls the mist-to-air
ratio of the inhaled aerosol, controlling the amount of drug delivered to the
user.
Based on design requirements, the air flow channel is routed such that it
initiates from the bottom of the sonication chamber 219. The opening at the
bottom of the aerosol chamber aligns with and is tightly adjacent to the
opening
to an airflow bridge in the device. The air flow channel runs vertically
upwards
along the reservoir and continues until the center of the sonication chamber
(concentric with the ultrasonic transducer 215). Here, it turns 90 inwards.
The
flow path then continues on until approximately 1.5mm from the ultrasonic
transducer 215. This routing ensures maximized ambient air supplied directly
in
the direction of the atomization surface of the ultrasonic transducer 215. The
air
flows through the channel, towards the transducer, collects the generated mist
as it travels out through the mist outlet port 208.
Referring now to Figures 33 and 34 of the accompanying drawings, a hookah
device 202 of some arrangements is configured to releasably attach to an
existing hookah 246. The hookah device 202 attaches to the stem 247 in place
of a conventional hookah head which would otherwise house the tobacco and
the charcoal (or electronic heating element).
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The hookah 246 comprises a water chamber and an elongate stem 247 having
a first end which is attached to the water chamber. The stem 247 comprises a
mist flow path which extends from a second end of the stem 247, through the
stem 247, to the first end and into the water chamber.
In this arrangement, the hookah device 202 is releasably attached to the
second end of the stem 247 of the hookah 246. However, in other
arrangements the hookah device 202 is not designed to be removable and is
instead fixed to or formed integrally with the stem 247 of the hookah 246.
Referring to Figures 35-43 of the accompanying drawings, the hookah device
202 comprises a housing 248 which incorporates a base 249 and a cover 250
which are attached or releasably attached to one another. In this arrangement,
the housing 248 is cylindrical and generally disk-shaped.
In this arrangement, the cover 250 is provided with a plurality of air inlets
251 to
allow air to be drawn into the hookah device 202. The base 249 is provided
with a hookah outlet port 252 to allow air and mist to flow out from the
hookah
device 202 and into the hookah 246. The diameter of the hookah outlet port
252 is sufficient to allow a user to draw air quickly through the hookah
device
202 and through the hookah 246 to generate bubbles of mist which travel
through the water in the hookah 246.
In this arrangement, the hookah outlet port 252 is a circular aperture which
receives the end of the stem 247 of the hookah 246. The hookah device 202 is
supported on the stem 247 of the hookah 246 with a generally gas-tight seal
being formed between the hookah device 202 and the stem 247.
In this arrangement, the hookah device 202 is a self-contained device with the
electronic components and mist generator devices containing e-liquid being
housed within the housing 248.
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In this arrangement, the hookah device 202 comprises an upper support plate
253, a middle support plate 254 and a lower support plate 255 which are
stacked on top of one another. The support plates 253-255 support a plurality
of mist generator devices 201 within the hookah device 202. Each mist
generator device is a mist generator device 201 as described in this
disclosure.
In this arrangement, the mist generator devices 201 a releasably attached to
the hookah device 202 so that the mist generator devices 201 can be replaced
when empty (i.e. when the e-liquid is partially or completely depleted).
In this arrangement, the hookah device 202 comprises four mist generator
devices 201 which are controlled by the controller of the hookah device 202.
In
other arrangements, the hookah device 202 comprises a plurality of mist
generator devices 201, such as at least two mist generator devices 201.
The hookah device 202 is provided with first contact terminals 259 which
establish and electrical connection between the controller of the hookah
device
202 and the electrical contacts 232 and 233 of each mist generator device 201.
The hookah device 202 is provided with second contact terminals 260 which
establish and electrical connection between the controller of the hookah
device
202 and the electrical contacts 241 on the OTP PCB of each mist generator
device 201.
In this arrangement, the hookah device 202 comprises an upper printed circuit
board (PCB) 256 which is positioned on top of the upper support plate 253 and
a middle PCB 257 which is positioned between the middle support plate 254
and the lower support plate 255. A lower PCB 258 is positioned beneath the
lower support plate 255. The PCBs 256-258 carry the electronic components
which make up a driver device of the hookah device 202. The PCBs 256-258
are coupled electrically to one another to allow the electronic components on
each PCB 256-258 to communicate with one another.
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While there are three PCBs 256-258 in this arrangement, other arrangements
comprise only one PCB or a plurality of PCBs which perform the same
functions of the driver device of the hookah device 202.
In this arrangement, the hookah device 202 comprises a plurality of magnets
261 which enable the support plates 253-255 to be releasably attached to one
another. Once the hookah device 202 is assembled with the support plates
253-255 and the PCBs 256-258 stacked on top of one another with the mist
generator device 201 retained between the support plates 253-255, the cover
250 is placed onto the base 249 and a plurality of screws 262 are used to
releasably attach the cover 250 to the base 249.
The upper support plate 253 comprises a manifold 263 which is positioned
centrally on one side of the upper support plate 253. In this arrangement, the
manifold 263 is provided with four apertures 264 (only one of which is visible
in
Figure 40) which each receive the outlet port 208 of a respective mist
generator
device 201. In this arrangement, the hookah device 202 comprises four mist
generator devices 201 which are releasably coupled to the manifold at 90
relative to one another. In other arrangements, the manifold 263 comprises a
different number of apertures 264 to correspond with the number of mist
generator devices 201 being used with the hookah device 202.
The manifold 263 comprises a manifold pipe 265 which is in fluid
communication with the apertures 264 such that mist generated by the mist
generator devices 201 can combine and flow down from the manifold 263 and
out of the manifold pipe 265. When the hookah device 202 is assembled, the
manifold pipe 265 extends through an aperture 266 in the middle support plate
254 and an aperture 267 in the middle PCB 257. The manifold pipe 265 then
connects to an outlet pipe 268 which extends through the lower support plate
255 to provide a fluid flow path through the lower support plate to the hookah
outlet port 252 of the hookah device 202.
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The outlet pipe 268 extends downwardly from the underside of the lower
support plate 255 and through and aperture 269 in the lower PCB 258. The
outlet pipe 268 then extends through an aperture 270 in the base 249 of the
hookah device 202. In this arrangement, the outlet pipe 268 and the hookah
outlet port 252 are a hookah attachment arrangement 271 which attaches or is
configured to attach the hookah device 202 to a hookah 246. In this
arrangement, the hookah device 202 is attached to the hookah 246 by inserting
part of the stem 247 of the hookah into the hookah outlet port 252.
The hookah outlet port 252 provides a fluid flow path 272, as shown in Figures
42 and 43, from the mist outlet ports 208 of the mist generator devices 201
and
out of the hookah device 202 such that mist generated by the mist generator
devices 201 flows out from the hookah device 202 and into the hookah 246.
The mixture of air and mist creates bubbles in the water of the hookah 246.
The bubbles escape the water surface with the mist rising above the surface of
water in the water bowl of the hookah and travel through the pipe to the user
during inhalation.
In this arrangement, the upper PCB 256 carries a pressure sensor which
senses the pressure of air in the vicinity of the mist outlet ports 208 of the
mist
generator devices 201. The pressure sensor thereby detects a negative
pressure in the vicinity of the mist outlet ports 208 when a user draws on the
hookah and sucks air through the mist generator devices 201 along the fluid
flow path 272. The pressure sensor provides a signal to the controller of the
hookah device, as described below, for the controller to activate at least one
of
the mist generator devices 201 to generate mist as the user draws on the
hookah.
In this arrangement, the lower PCB 258 carries power control components 273
which control and distribute power to the other electronic components of the
hookah device 202. In some arrangements, the power control components 273
receive power from an external power source, such as a mains power adapter,
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which is releasably attached to the hookah device 202. In this arrangement,
the hookah head 202 is configured to be powered by an external power adaptor
at a DC voltage in the range 20V to 40V.
In other arrangements, the hookah device 202 comprises a battery which is
integrated within the hookah device 202 and connected to the power control
components 273. In some arrangements, the battery is a rechargeable Li-Po
battery. In some arrangements, the battery is configured to output a 20V to
40V DC voltage. In some arrangements, the battery has a high discharge rate.
The high discharge rate is necessary for the voltage amplification that is
required by the ultrasonic transducers of the mist generator devices 201. Due
to the requirement of having a high discharge rate, the Li-Po battery of some
arrangements is designed specifically for continuous current draw. In some
arrangements, a charging port is provided on the hookah device 202 to enable
the battery to be charged by an external power source.
The middle PCB 257 incorporates a processor 274 and a memory 275 of a
controller or computing device of the hookah device 202. In this arrangement,
the processor 274 and the memory 275 are components of the driver device
within the hookah device 202. In this arrangement, the functionality of the
driver device is implemented in executable instructions which are stored in
the
memory 275 which, when executed by the processor 274, cause the processor
274 to control the driver device to perform at least one function. The driver
device is connected electrically to each of the mist generator devices 201. In
this arrangement, the driver device of the hookah device 202 is coupled for
communication with each mist generator device 201 by a data bus, such as an
I2C data bus. In this arrangement, each mist generator device 201 is
identified
by a unique identifier which is used when controlling the mist generator
device
201 via the data bus. In some arrangements, the unique identifier is stored in
the OTP IC of the mist generator device 201.
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In some arrangements, the driver device controls each respective mist
generator device independently.
In some arrangements, the control
functionality is implemented in executable instructions stored in the memory
275. The independent control configuration enables the driver device to
activate or deactivate each mist generator device 201 independently of the
other mist generator devices 201. The driver device can therefore control one
or more of the mist generator devices 201 to generate mist simultaneously or
alternately according to predetermined requirements.
In some arrangements, the driver device controls the mist generator devices
201 to activate and/or deactivate successively in sequence.
In some
arrangements the sequence of activation of the mist generator devices 201
optimizes the operation of the hookah device 202 by ensuring that mist is
generated sufficiently quickly to allow the mist to pass in bubbles through
the
water in the water chamber of the hookah. The hookah device 202 of some
arrangements thereby enables bubbles of mist to be drawn at high velocity
through the water in the water chamber as a user draws on the hookah
mouthpiece. Consequently, water soluble compounds (e.g. vegetable glycerin,
flavorings, etc.) are able to travel through the water in in the bubbles of
mist for
inhalation by a user.
In some arrangements, the driver device controls the mist generator devices
201 to activate for a predetermined length of time one after another in
sequence. In some arrangements, the driver device controls the mist generator
devices 201 to activate in rotation such that the mist generator devices 201
are
activated one after the other and/or one at a time in a clockwise or
anticlockwise direction.
In some arrangements, the driver device controls the mist generator devices
201 to activate in pairs. In some arrangements, the driver device controls two
mist generator devices 201 to activate simultaneously: either two mist
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generator devices 201 that are adjacent to one another or two mist generator
devices that are opposite one another.
In some arrangements, the driver device is configured to ensure that a mist
generator device 201 is not activated if it is not properly wicked with e-
liquid in
its capillary 222 or if the liquid chamber 218 empty or nearly empty of e-
liquid.
This provides protection for the hookah device 202 by ensuring that the hookah
device 202 maintains correct operation.
The electronics of the driver device of the hookah device 202 (distributed
across the PCBs 256-258) are divided as discussed below. The following
description refers to the control of one mist generator device 201 but it is
to be
appreciated that the driver device of the hookah device 202 controls each mist
generator device 201 independently in the same way.
In order to obtain the most efficient aerosolization, with particle size below
1um,
the driver device provides the contacts pads receiving the ultrasonic
transducer
215 (piezoelectrical ceramic disc (PZT)) with high adaptive frequency
(approximately 3MHz).
This section not only has to provide high frequency but also protect the
ultrasonic transducer 215 against failures while providing constant optimized
cavitation.
PZT mechanical deformation is linked to the AC Voltage amplitude that is
applied to it, and in order to guarantee optimal functioning and delivery of
the
system at every sonication, the maximum deformation must be supplied to the
PZT all the time.
However, in order to prevent the failure of the PZT, the active power
transferred
to it must be precisely controlled.
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The processor 274 and the memory 275 are configured to control modulation of
the active power given to the PZT at every instant without compromising the
mechanical amplitude of vibration of the PZT.
By Pulse Width Modulation (PWM) of the AC voltage applied to the PZT, the
mechanical amplitude of the vibration remains the same.
Indeed, the RMS voltage applied would be the same with effective Duty Cycle
modulation as with Voltage modulation, but the active power transferred to the
PZT would degrade. Indeed, given the formula below:
V-2-
Active Power displayed to the PZT being Pa ¨ 2 Irms *Vrms * casco,
z
Where
co is the shift in phase between current and voltage
Irrns is the root mean square Current
Vrms is the root mean square Voltage.
When considering the first harmonic, Irms is a function of the real voltage
amplitude applied to the transducer, as the pulse width modulation alters the
duration of voltage supplied to the transducer, controlling Irms.
The specific design of the PMIC uses a state-of-the-art design, enabling ultra-
precise control of the frequency range and steps to apply to the PZT including
a
complete set of feedback loops and monitoring path for the control section to
use.
In this arrangement, the driver device comprises a DC/DC boost converter and
transformer that carry the necessary power to the PZT contact pads.
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In this arrangement, the driver device comprises an AC driver for converting a
voltage from the battery into an AC drive signal at a predetermined frequency
to drive the ultrasonic transducer.
The driver device comprises an active power monitoring arrangement for
monitoring the active power used by the ultrasonic transducer (as described
above) when the ultrasonic transducer is driven by the AC drive signal. The
active power monitoring arrangement provides a monitoring signal which is
indicative of an active power used by the ultrasonic transducer.
The processor 274 within the driver device controls the AC driver and receives
the monitoring signal drive from the active power monitoring arrangement.
The memory 275 of driver device stores instructions which, when executed by
the processor, cause the processor to:
A. control the AC driver to output an AC drive signal to the ultrasonic
transducer at a predetermined sweep frequency.
B. calculate the active power being used by the ultrasonic transducer
based on the monitoring signal;
C. control the AC driver to modulate the AC drive signal to maximize the
active power being used by the ultrasonic transducer;
D. store a record in the memory of the maximum active power used by
the ultrasonic transducer and the sweep frequency of the AC drive signal;
E. repeat steps A-D for a predetermined number of iterations with the
sweep frequency incrementing with each iteration such that, after the
predetermined number of iterations has occurred, the sweep frequency has
been incremented from a start sweep frequency to an end sweep frequency;
F. identify from the records stored in the memory the optimum frequency
for the AC drive signal which is the sweep frequency of the AC drive signal at
which a maximum active power is used by the ultrasonic transducer; and
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G. control the AC driver to output an AC drive signal to the ultrasonic
transducer at the optimum frequency to drive the ultrasonic transducer to
atomize a liquid.
In some arrangements, the active power monitoring arrangement comprises a
current sensing arrangement for sensing a drive current of the AC drive signal
driving the ultrasonic transducer, wherein the active power monitoring
arrangement provides a monitoring signal which is indicative of the sensed
drive current.
In some arrangements, the current sensing arrangement comprises an Analog-
to-Digital Converter which converts the sensed drive current into a digital
signal
for processing by the processor.
In some arrangements, the memory stores instructions which, when executed
by the processor, cause the processor to: repeat steps A-D above with the
sweep frequency being incremented from a start sweep frequency of 2900kHz
to an end sweep frequency of 2960kHz.
In some arrangements, the memory stores instructions which, when executed
by the processor, cause the processor to: repeat steps A-D above with the
sweep frequency being incremented from a start sweep frequency of 2900kHz
to an end sweep frequency of 3100kHz.
In some arrangements, the memory stores instructions which, when executed
by the processor, cause the processor to: in step G, control the AC driver to
output an AC drive signal to the ultrasonic transducer at frequency which is
shifted by a predetermined shift amount from the optimum frequency.
In some arrangements, the predetermined shift amount is between 1-10% of
the optimum frequency.
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The pressure sensor used in the device serves two purposes. The first purpose
is to prevent unwanted and accidental start of the sonic engine (driving the
ultrasonic transducer). This functionality is implemented in the processing
arrangement of the device, but optimized for low power, to constantly measures
environmental parameters such as temperature and ambient pressure with
internal compensation and reference setting in order to accurately detect and
categories what is called a true inhalation.
The second purpose of the pressure sensor is to be able to monitor not only
the
exact duration of the inhalations by the user for precise inhalation volume
measurement, but also to be able to determine the strength of the user
inhalation. All in all, we are able to completely draw the pressure profile of
every inhalation and anticipate the end of an inhalation for aerosolization
optimization.
In some arrangements, the hookah device 202 comprises a BluetoothTM Low
Energy (BLE) microcontroller. Indeed, this enables the setting to provide
extremely accurate inhalation times, optimized aerosolization, monitor
numerous parameters to guarantee safe misting and prevent the use of non-
genuine e-liquids or aerosol chambers and protect both the device against
over-heating risks and the user against over-misting in one shot.
The use of the BLE microcontroller allows over-the-air update to continuously
provide improved software to users based on anonymized data collection and
trained Al for PZT modelling.
The hookah device 202 is a precise, reliable and a safe aerosolization
solution
for daily customer usage and, as such, must provide a controlled and trusted
aerosolization.
This is performed through an internal method that can be broken apart into
several sections as follows:
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Sonication
In order to provide the most optimal aerosolization the ultrasonic transducer
(PZT) or each mist generator device 201 needs to vibrate in the most efficient
way.
Frequency
The electromechanical properties of piezoelectrical ceramics state that the
component has the most efficiency at the resonant frequency. But also,
vibrating a PZT at resonance for a long duration will inevitably end with the
failure and breaking of the component which renders the aerosol chamber
unusable.
Another important point to consider when using piezoelectrical materials is
the
inherent variability during manufacturing and its variability over temperature
and lifetime.
Resonating a PZT at 3MHz in order to create droplets of a size <1 urn requires
an adaptive method in order to locate and target the 'sweet spot' of the
particular PZT inside every aerosol chamber used with the device for every
single inhalation.
Sweep
Because the device has to locate the 'sweet spot' for every single inhalation
and because of over-usage, the PZT temperature varies as the device uses an
in-house double sweep method.
The first sweep is used when the device has not been used with a particular
aerosol chamber for a time that is considered enough for all the thermal
dissipation to occur and for the PZT to cool down to 'default temperature'.
This
procedure is also called a cold start. During this procedure the PZT needs a
boost in order to produce the required aerosol. This is achieved by only going
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over a small subset of Frequencies between 2900kHz to 2960kHz which,
considering extensive studies and experiments, covers the resonant point.
For each frequency in this range, the sonic engine in activated and the
current
going through the PZT is actively monitored and stored by the microcontroller
via an Analog-to-Digital Converter (ADC), and converted back to current in
order to be able to precisely deduct the Power used by the PZT.
This yields the cold profile of this PZT regarding frequency and the Frequency
used throughout the inhalation is the one that uses the most current, meaning
the lowest impedance Frequency.
The second sweep is performed during any subsequent inhalation and cover
the entire range of frequencies between 2900kHz to 3100kHz due to the
modification of the PZT profile with regards to temperature and deformation.
This hot profile is used to determine the shift to apply.
Shift
Because the aerosolization must be optimal, the shift is not used during any
cold inhalation and the PZT will hence vibrate at resonant frequency. This can
only happen for a short and unrepeated duration of time otherwise the PZT
would inevitably break.
The shift however is used during most of inhalations as a way to still target
a
low impedance frequency, thus resulting in quasi-optimal operation of the PZT
while protecting it against failures.
Because the hot and cold profiles are stored during inhalation the
microcontroller can then select the proper shifted frequency according to the
measured values of current through the PZT during sweep and ensure a safe
mechanical operation.
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The selection of the direction to shift is crucial as the piezoelectrical
component
behaves in a different way if outside the duplet resonant/anti-resonant
frequency or inside this range. The selected shift should always be in this
range
defined by Resonant to anti-Resonant frequencies as the PZT is inductive and
not capacitive.
Finally, the percentage to shift is maintained below 10% in order to still
remain
close to the lowest impedance but far enough of the resonance.
Adjustment
Because of the intrinsic nature of PZTs, every inhalation is different.
Numerous
parameters other than the piezoelectrical element influence the outcome of the
inhalation, like the amount of e-liquid remaining inside the aerosol chamber,
the
wicking state of the gauze or the battery level of the device.
As of this, the device permanently monitors the current used by the PZT inside
the aerosol chamber and the microcontroller constantly adjusts the parameters
such as the frequency and the Duty Cycle in order to provide the aerosol
chamber with the most stable power possible within a pre-defined range that
follows the studies and experimental results for most optimal safe
aerosolization.
Battery monitoring
In some arrangements, a battery is integrated within the hookah device 202. In
these arrangements, the hookah device 202 is powered by a DC Li-Po battery
which provides a required voltage to the hookah device 202. Due to the
requirement of having a high discharge rate, the Li-Po battery of some
arrangement is designed specifically for continuous current draw.
Because the battery voltage drops and varies a lot when activating the
sonication section, the microcontroller constantly monitors the power used by
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the PZT inside the aerosol chamber to ensure a proper but also safe
aerosolization.
And because the key to aerosolization is control, the device ensures first
that
the Control and Information section of the device always function and does not
stop in the detriment of the sonication section.
This is why the adjustment method also takes into great account the real time
battery level and, if need be, modifies the parameters like the Duty Cycle to
maintain the battery at a safe level, and in the case of a low battery before
starting the sonic engine, the Control and Information section will prevent
the
activation.
Power control
As being said, the key to aerosolization is control and the method used in the
device is a real time multi-dimensional function that takes into account the
profile of the PZT, the current inside the PZT and the battery level of the
device
at all time.
All this is only achievable thanks to the use of a microcontroller that can
monitor and control every element of the device to produce an optimal
inhalation.
Interval
Because the device relies on a piezoelectrical component, the device prevents
the activation of the sonication section if an inhalation stops. The safety
delay
in between two inhalations is adaptive depending on the duration of the
previous one. This allows the gauze to wick properly before the next
activation.
With this functioning, the device can safely operate and the aerosolization is
rendered more optimal with no risk of breaking the PZT element nor exposing
the user to toxic components.
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Connectivity (BLE)
The device Control and Information section is composed of a wireless
communication system in the form of a Bluetooth Low Energy capable
microcontroller. The wireless communication system is in communication with
the processor of the device and is configured to transmit and receive data
between the driver device and a computing device, such as a smartphone.
The connectivity via Bluetooth Low Energy to a companion mobile application
ensures that only small power for this communication is required thus allowing
the device to remain functioning for a longer period of time if not used at
all,
compared to traditional wireless connectivity solutions like Wi-Fi, classic
Bluetooth, GSM or even LTE-M and NB-I0T.
Most importantly, this connectivity is what enables the OTP as a feature and
the complete control and safety of the inhalations. Every data from resonant
frequency of an inhalation to the one used, or the negative pressure created
by
the user and the duration are stored and transferred over BLE for further
analysis and improvements of the embedded software.
Finally, this connectivity enables the update of the embedded firmware inside
the device and over the air (OTA), which guarantees that the latest versions
can always be deployed rapidly. This gives great scalability to the device and
insurance that the device is intended to be maintained.
Because the aerosolization of the e-liquid is achieved via the mechanical
action
of the piezoelectric disc and not due to the direct heating of the liquid, the
individual components of the e-liquid (propylene glycol, vegetable glycerin,
flavoring components, etc.) remain largely in-tact and are not broken into
smaller, harmful components such as acrolein, acetaldehyde, formaldehyde,
etc. at the high rate seen in traditional ENDS.
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All of the above applications involving ultrasonic technology can benefit from
the optimization achieved by the frequency controller which optimizes the
frequency of sonication for optimal performance.
It is to be appreciated that the disclosures herein are not limited to use for
nicotine delivery. The devices disclosed herein are for use with any drugs or
other compounds (e.g. CBD), with the drug or compound being provided in a
liquid within the liquid chamber of the device for aerosolization by the
device.
The hookah device 202 of some arrangements is a healthier alternative to
conventional hookah heads which burn tobacco using heat from charcoal or an
electrical element.
Nevertheless, the hookah device 202 of some
arrangements still provides the same user experience as a conventional
hookah due to the mist bubbles in the water of the hookah. Users are therefore
likely to want to use the ultrasonic hookah device 202 of some arrangements
instead of a conventional tobacco-burning hookah and thereby avoid the
dangers of smoking tobacco in a hookah.
The foregoing outlines features of several arrangements, examples or
embodiments so that those of ordinary skill in the art may better understand
various aspects of the present disclosure. Those of ordinary skill in the art
should appreciate that they may readily use the present disclosure as a basis
for designing or modifying other processes and structures for carrying out the
same purposes and/or achieving the same advantages of various examples or
embodiments introduced herein. Those of ordinary skill in the art should also
realize that such equivalent constructions do not depart from the spirit and
scope of the present disclosure, and that they may make various changes,
substitutions, and alterations herein without departing from the spirit and
scope
of the present disclosure.
Although the subject matter has been described in language specific to
structural features or methodological acts, it is to be understood that the
subject
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matter of the appended claims is not necessarily limited to the specific
features
or acts described above. Rather, the specific features and acts described
above are disclosed as example forms of implementing at least some of the
claims.
Various operations of examples or embodiments are provided herein. The
order in which some or all of the operations are described should not be
construed to imply that these operations are necessarily order dependent.
Alternative ordering will be appreciated having the benefit of this
description.
Further, it will be understood that not all operations are necessarily present
in
each embodiment provided herein. Also, it will be understood that not all
operations are necessary in some examples or embodiments.
Moreover, "exemplary" is used herein to mean serving as an example,
instance, illustration, etc., and not necessarily as advantageous. As used in
this application, "or" is intended to mean an inclusive "or" rather than an
exclusive "or". In addition, "a" and "an" as used in this application and the
appended claims are generally be construed to mean "one or more" unless
specified otherwise or clear from context to be directed to a singular form.
Also, at least one of A and B and/or the like generally means A or B or both A
and B. Furthermore, to the extent that "includes", "having", "has", "with", or
variants thereof are used, such terms are intended to be inclusive in a manner
similar to the term "comprising". Also, unless specified otherwise, "first,"
"second," or the like are not intended to imply a temporal aspect, a spatial
aspect, an ordering, etc. Rather, such terms are merely used as identifiers,
names, etc. for features, elements, items, etc. For example, a first element
and
a second element generally correspond to element A and element B or two
different or two identical elements or the same element.
Also, although the disclosure has been shown and described with respect to
one or more implementations, equivalent alterations and modifications will
occur to others of ordinary skill in the art based upon a reading and
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understanding of this specification and the annexed drawings. The disclosure
comprises all such modifications and alterations and is limited only by the
scope of the following claims. In particular regard to the various functions
performed by the above described features (e.g., elements, resources, etc.),
the terms used to describe such features are intended to correspond, unless
otherwise indicated, to any features which performs the specified function of
the described features (e.g., that is functionally equivalent), even though
not
structurally equivalent to the disclosed structure. In addition, while a
particular
feature of the disclosure may have been disclosed with respect to only one of
several implementations, such feature may be combined with one or more
other features of the other implementations as may be desired and
advantageous for any given or particular application.
Examples or embodiments of the subject matter and the functional operations
described herein can be implemented in digital electronic circuitry, or in
computer software, firmware, or hardware, including the structures disclosed
in
this specification and their structural equivalents, or in combinations of one
or
more of them.
Some examples or embodiments are implemented using one or more modules
of computer program instructions encoded on a computer-readable medium for
execution by, or to control the operation of, a data processing apparatus. The
computer-readable medium can be a manufactured product, such as hard drive
in a computer system or an embedded system. The computer-readable
medium can be acquired separately and later encoded with the one or more
modules of computer program instructions, such as by delivery of the one or
more modules of computer program instructions over a wired or wireless
network. The computer-readable medium can be a machine-readable storage
device, a machine-readable storage substrate, a memory device, or a
combination of one or more of them.
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The terms "computing device" and "data processing apparatus" encompass all
apparatus, devices, and machines for processing data, including by way of
example a programmable processor, a computer, or multiple processors or
computers. The apparatus can include, in addition to hardware, code that
creates an execution environment for the computer program in question, e.g.,
code that constitutes processor firmware, a protocol stack, a database
management system, an operating system, a runtime environment, or a
combination of one or more of them. In addition, the apparatus can employ
various different computing model infrastructures, such as web services,
distributed computing and grid computing infrastructures.
The processes and logic flows described in this specification can be performed
by one or more programmable processors executing one or more computer
programs to perform functions by operating on input data and generating
output.
Processors suitable for the execution of a computer program include, by way of
example, both general and special purpose microprocessors, and any one or
more processors of any kind of digital computer. Generally, a processor will
receive instructions and data from a read-only memory or a random access
memory or both. The essential elements of a computer are a processor for
performing instructions and one or more memory devices for storing
instructions and data. Generally, a computer will also include, or be
operatively
coupled to receive data from or transfer data to, or both, one or more mass
storage devices for storing data, e.g., magnetic, magneto-optical disks, or
optical disks. However, a computer need not have such devices. Devices
suitable for storing computer program instructions and data include all forms
of
non-volatile memory, media and memory devices.
In the present specification "comprise" means "includes or consists of" and
"comprising" means "including or consisting of".
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The features disclosed in the foregoing description, or the following claims,
or
the accompanying drawings, expressed in their specific forms or in terms of a
means for performing the disclosed function, or a method or process for
attaining the disclosed result, as appropriate, may, separately, or in any
combination of such features, be utilized for realizing the invention in
diverse
forms thereof.
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