PIEZOELECTRIC FLUID DISPENSER
20180207030 ยท 2018-07-26
Inventors
Cpc classification
B05B1/086
PERFORMING OPERATIONS; TRANSPORTING
B05B9/0838
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
Fluid delivery devices and methods are described, where the device may comprise a piezoelectric actuator operatively coupled to an ampoule with fluid, under a preloading force. The ampoule may comprise a thin-walled thermoplastic package which includes one or more apertures positioned on the wall of the ampoule. The piezoelectric actuator may be configured to clamp at least partially around the circumference of the ampoule and apply oscillations to its wall. The oscillations, typically in ultrasonic frequency, produce cycles of acoustic pressure in the fluid, leading to ejection of the fluid droplets or streams from the apertures.
Claims
1. A dispensing apparatus, comprising: an ampoule containing a liquid to be dispensed and having a first portion and a second portion, wherein the first portion defines one or more apertures through a side wall of the first portion; and a piezoelectric assembly which is configured to impart an oscillation onto the side wall such that a stream of the liquid is dispensed from the one or more apertures.
2. The apparatus of claim 1 wherein the piezoelectric assembly is configured to secure the first portion and impart the oscillation onto the side wall.
3. The apparatus of claim 1 wherein the oscillation imparted upon the side wall comprises a primary oscillation to the first portion along a first direction such that a secondary oscillation is induced in the first portion along a second direction which is perpendicular to the first direction,
4. The apparatus of claim 3 wherein the primary oscillation and secondary oscillation are co-planar with one another and wherein the one or more apertures are aligned along the second direction such that the secondary oscillation dispenses the stream of the liquid through the one or more apertures.
5. The apparatus of claim 1 wherein the first portion defines a circular or oval cross-sectional shape.
6. The apparatus of claim 1 wherein the piezoelectric assembly comprises a vibratory structure that is configured to clamp upon the first portion of the container enclosure.
7. The apparatus of claim 6 wherein the first portion is secured to the clamp via an interference fit.
8. The apparatus of claim 6 wherein an operating frequency of the piezoelectric assembly is near or at a resonance frequency of the clamp.
9. The apparatus of claim 6 wherein a clamping force of the clamp upon the first portion is less than 5 N.
10. The apparatus of claim 1 wherein the piezoelectric assembly comprises a bending transducer configured to oscillate in a bending mode.
11. The apparatus of claim 10 wherein the bending transducer comprises a bimorph actuator having a first piezoceramic layer, a second piezoceramic layer, and a passive layer between the first and second piezoceramic layers.
12. The apparatus of claim 11 wherein the passive layer comprises a printed circuit board.
13. The apparatus of claim 10 wherein the bending transducer comprises a unimorph actuator having a piezoceramic layer.
14. The apparatus of claim 1 further comprising electronic circuitry programmed to drive the piezoelectric assembly.
15. The apparatus of claim 1 wherein the oscillation amplitude is greater than 300 nm.
16. The apparatus of claim 1 wherein the liquid comprises ophthalmic medication.
17. The apparatus of claim 1 further comprising an optical alignment system which enables a patient to align the one or more apertures to a targeted region on a surface of an eye of a patient.
18. A fluid dispensing apparatus, comprising: a fluid reservoir having a proximal section and a distal section, wherein a side surface of the proximal section defines one or more apertures; a clamp member which defines a receiving channel sized to retain the proximal section of the fluid reservoir; and a piezoelectric actuator in vibrational communication with the clamp member, wherein actuation of the piezoelectric actuator deforms the clamp member to impart a primary oscillation to the proximal section along a first direction such that a secondary oscillation is induced in the proximal section along a second direction which is perpendicular to the first direction, wherein the primary oscillation and secondary oscillation are co-planar with one another, and wherein the one or more apertures are aligned along the second direction such that the secondary oscillation induced within the proximal section is sufficient to eject a fluid through the one or more apertures.
19. The apparatus of claim 18 wherein the piezoelectric actuator comprises: a first piezoelectric member in vibrational communication with the clamp member, wherein the first piezoelectric member has a first poling direction; and a second piezoelectric member in vibrational communication with the clamp member, the second piezoelectric member being aligned relative to the first piezoelectric member such that the second piezoelectric member is oriented to have a second poling direction opposite to the first poling direction,
20. The apparatus of claim 19 wherein the first and second piezoelectric members deform at least two opposed jaw members of the clamp member to cyclically clamp upon a circumference of the proximal section of the fluid reservoir when actuated.
21. The apparatus of claim 19 wherein the first and second piezoelectric members each comprise a piezo-ceramic plate.
22. The apparatus of claim 19 further comprising a printed circuit board having piezoelectric driver circuitry, wherein the clamp member is secured to the printed circuit board.
23. The apparatus of claim 22 wherein the first piezoelectric member is mounted upon a first surface of the printed circuit board and the second piezoelectric member is mounted upon a second surface of the printed circuit board which is opposite of the first surface.
24. The apparatus of claim 18 wherein the proximal section comprises a conduit portion and the distal section comprises a bulb portion.
25. The apparatus of claim 24 wherein the one or more apertures are positioned on a wall of the conduit portion.
26. The apparatus of claim 18 wherein the clamp member comprises a base plate and at least two opposed jaw members extending from the base and forming the receiving channel.
27. The apparatus of claim 26 wherein a deformation amplitude of the at least two opposed jaw members is less than 2 microns.
28. The apparatus of claim 26 wherein a frequency response of the at least two opposed jaw members is at least 22,000 Hz.
29. The apparatus of claim 26 wherein the at least two opposed jaw members engage with the proximal section of the fluid reservoir via an interference fit.
30. The apparatus of claim 26 wherein an operating frequency of the piezoelectric assembly is near or at a resonance frequency of the clamp member.
31. The apparatus of claim 18 wherein the acoustic pressure is produced such that the fluid is ejected through the one or more apertures as single drops or as a continuous stream.
32. The apparatus of claim 18 wherein the acoustic pressure is produced such that the fluid is ejected through the one or more apertures in a volume of less than one nano-liter.
33. The apparatus of claim 18 further comprising a housing within which the fluid dispensing apparatus is contained.
34. The apparatus of claim 18 further comprising an optical alignment system which enables a patient to align the one or more apertures to a targeted region on a surface of an eye of the patient.
35. The apparatus of claim 18 wherein the fluid reservoir comprises a squeeze bottle.
36. A method of dispensing a fluid, comprising: providing a piezoelectric assembly coupled to a fluid reservoir having a first portion and a second portion; imparting an oscillation onto a side wall of the first portion; and ejecting a fluid from one or more apertures defined along the side wall such that a stream of the liquid is dispensed.
37. The method of claim 36 wherein imparting an oscillation comprises imparting a primary oscillation along a first direction to the first portion of the fluid reservoir such that a secondary oscillation is induced in the first portion along a second direction which is perpendicular to the first direction, wherein the primary oscillation and second oscillation are co-planar with one another.
38. The method of claim 36 wherein providing further comprises securing the first portion of the fluid reservoir within the piezoelectric assembly.
39. The method of claim 38 wherein securing comprises engaging the first portion within the piezoelectric assembly via an interference fit.
40. The method of claim 38 wherein securing comprises positioning the first portion within a clamp member of the piezoelectric assembly.
41. The method of claim 40 wherein imparting comprises operating the clamp member at an operating frequency of the piezoelectric assembly near or at a resonance frequency of the clamp member.
42. The method of claim 46 wherein imparting comprises actuating a first piezoelectric member having a first poling direction and actuating a second piezoelectric member having a second poling direction opposite to the first poling direction.
43. The method of claim 41 further comprising deforming a securement mechanism securing the first portion of the fluid reservoir such that the securement mechanism cyclically clamps upon a circumference of the first portion of the fluid reservoir when actuated.
44. The method of claim 42 wherein deforming comprises imparting a deformation amplitude of less than 2 microns to the securement mechanism.
45. The method of claim 42 wherein deforming comprises imparting a deformation amplitude at a frequency response of at least 22,000 Hz.
46. The method of claim 36 further comprising controlling an actuation of the piezoelectric assembly via a printed circuit board having piezoelectric driver circuitry.
47. The method of claim 36 wherein the fluid reservoir comprises an ampoule where the first portion comprises a conduit portion and the second portion comprises a bulb portion.
48. The method of claim 36 wherein ejecting comprises ejecting the fluid through the one or more apertures as single drops or as a continuous stream.
49. The method of claim 36 wherein ejecting comprises ejecting the fluid with a volume of less than one nano-liter.
50. The method of claim 36 further comprising aligning the one or more apertures to a targeted region on a surface of an eye of a subject prior to ejecting the fluid.
51. A device for emitting a fluid, comprising: at least one piezoelectric actuator configured to vibrate at a selected frequency; an ampoule configured to dispense a fluid through an aperture; a vibrational transmission component defining a longitudinal axis and having an elongate section and a mounting section, wherein the elongate section defines a lumen as it transitions from the mounting section, and wherein the at least one piezoelectric actuator is attached to the mounting section and the ampoule is removably attachable to the elongate section such that the aperture is aligned with the longitudinal axis when assembled.
52. The device of claim 51 wherein the piezoelectric actuator comprises a first piezoelectric plate and a second piezoelectric plate each attached on opposite sides of the mounting section.
53. The device of claim 52 wherein the first and second piezoelectric plates are each operable at a resonance frequency of the vibrational transmission component.
54. The device of claim 52 wherein the first and second piezoelectric plates are each configured to impart a vibrational mode which causes expansion and contraction of the mounting section in parallel with the longitudinal axis.
55. The device of claim 52 wherein the first and second piezoelectric plates have a similar polarity orientation such that the plates expand and contract simultaneously and without a phase shift therebetween.
56. The device of claim 51 wherein the mounting section defines opposing flattened mounting surfaces which are aligned symmetrically and in parallel relative to one another and relative to the longitudinal axis.
57. The device of claim 51 wherein the elongate section is formed as a tubular section.
58. The device of claim 57 wherein the tubular section defines a uniform wall thickness.
59. The device of claim 51 wherein the elongate section has a length of between 1 to 10 cm.
60. The device of claim 51 wherein the ampoule has a volume of about 0.5 to 3 ml.
61. The device of claim 51 wherein the fluid comprises an ophthalmic composition.
62. The device of claim 51 wherein the ampoule comprises an insert configured to form an annular gap between an outer wall of the insert and an inner wall of the ampoule.
63. The device of claim 62 wherein the annular gap ranges from 0.3 to 1 mm.
64. The device of claim 62 wherein the ampoule further defines a venting hole.
65. The device of claim 62 wherein the ampoule comprises a flange for securement against the elongate section.
66. The device of claim 62 wherein the ampoule comprises one or more protrusions positioned on an outer surface of the ampoule for engagement with the elongate section.
67. The device of claim 51 wherein the ampoule further comprises an engagement rod extending proximally from a body of the ampoule for coupling to the distal end of the elongate section.
68. The device of claim 67 wherein the ampoule further comprises a distal tapered section which narrows from the body to the aperture.
69. The device of claim 51 further comprising an ampoule engagement feature for attachment to the distal end of the elongate section and to the ampoule.
70. The device of claim 69 wherein the ampoule engagement feature aligns with the longitudinal axis such that the ampoule is positioned at a point of maximum displacement of the ampoule engagement feature when actuated.
71. The device of claim 51 wherein the vibrational transmission component is formed of a thermoplastic having a modulus of elasticity greater than 3 GPa.
72. The device of claim 51 further comprising a pulse generator configured to actuate the piezoceramic actuator at a frequency that is equal to a natural frequency of the vibrational transmission component.
73. The device of claim 72 wherein the pulse generator is configured to dispense the fluid from the aperture in a continuous stream of fluid.
74. The device of claim 51 further comprising an optical fixture for aligning the aperture to a surface of an eye, wherein the optical fixture comprises a light source which is in parallel and offset relative to the aperture.
75. The device of claim 74 wherein the offset is 4 to 12 mm.
76. A method of emitting a fluid, comprising: securing an ampoule to a vibrational transmission component defining a longitudinal axis and having an elongate section and a mounting section such that an aperture defined by the ampoule is aligned with the longitudinal axis; actuating at least one piezoelectric actuator secured to the mounting section such that vibrations are transmitted from the mounting section, through the elongate section, and to the ampoule; and emitting a fluid from the ampoule and through the aperture.
77. The method of claim 76 wherein securing an ampoule comprises removably coupling an engagement rod extending proximally from a body of the ampoule to a distal end of the elongate section.
78. The method of claim 76 wherein actuating at least one piezoelectric actuator comprises vibrating a first piezoelectric plate and a second piezoelectric plate each attached on opposite sides of the mounting section.
79. The method of claim 76 wherein actuating at least one piezoelectric actuator comprises actuating a pulse generator to vibrate the vibrational transmission component at a frequency that is equal to a natural longitudinal frequency of the vibrational transmission component.
80. The method of claim 76 wherein emitting a fluid comprises emitting the fluid from the aperture in a continuous stream of fluid.
81. The method of claim 76 wherein emitting a fluid comprises emitting an ophthalmic composition.
82. The method of claim 76 further comprising aligning a light source with an optical axis of an eye to be treated, wherein the light source is aligned offset and in parallel with the aperture.
83. The method of claim 76 wherein emitting a fluid comprises drawing the fluid via capillary action through an annular gap which is in fluid communication with the aperture, wherein the annular gap is formed within the ampoule via an insert positioned within.
84. The method of claim 83 wherein the annular gap ranges from 0.3 to 1 mm.
85. A fluid reservoir apparatus, comprising: an ampoule body having a cylindrical portion and a tapered portion which narrows into an opening defining an aperture which is in fluid communication with a volume defined by the ampoule body; and an insert having an outer surface which follows an inner surface of the ampoule body in a corresponding manner such that an annular capillary passage which is in fluid communication with the aperture is formed between the outer surface and inner surface.
86. The apparatus of claim 85 wherein the ampoule body further defines a venting hole.
87. The apparatus of claim 85 wherein the ampoule body further comprises a flange radially extending from an external surface of the ampoule body.
88. The apparatus of claim 85 wherein the ampoule body further comprises one or more protrusions which extend from an external surface of the ampoule body.
89. The apparatus of claim 85 wherein the insert defines one or more openings around a circumference of the insert.
90. The apparatus of claim 85 wherein the inner surface of the ampoule body and the outer surface of the insert have a hydrophilic coating.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Having thus summarized the general nature of the invention and some of its features and advantages, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which:
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DETAILED DESCRIPTION OF THE INVENTION
[0058] The various embodiments of the invention described herein relates to a device for drug delivery to the ocular surface for treatment of ophthalmic diseases. In the systems and methods described herein droplets are dispensed in high frequency but in a single drop format or in a continuous stream depending on the electric signal input as described earlier. When droplets are produced they generally have ultra-small volumes ranging from about a few hundred pico-liters to about one nano-liters. Generally, droplets of such volume or a continuous (or discontinuous) collimated single stream do not cause blinking reflex.
[0059] The dispensing devices and clamping actuators described herein may be utilized with any of the embodiments described in further detail in the following references and in any combination: U.S. patent application Ser. No. 14/992,975 filed Jan. 11, 2016 (U.S. Pat. Pub. 2016/0199225); U.S. patent application Ser. No. 15/094,849 filed Apr. 8, 2016 (U.S. Pat. Pub. 2016/0296367), each of which is incorporated herein by reference in its entirety and for any purpose herein. Additionally and/or alternatively, although the devices and methods are described for ejecting droplets or a stream of fluid into or upon the surface of an eye for ophthalmic treatment, the devices and methods may be utilized for any number of non-ophthalmic applications as well, e.g., otologic (e.g. ear drum); endoscopic (e.g., gastrointestinal tract); gynecologic (e.g. cervical, uterine, reproductive care (fallopian tube)); laparoscopic (e.g., body cavity, abdominal); laryngoscopic (e.g., throat, vocal cords); bronchoscopic (e.g., bronchi or other lung tissue); urologic (e.g., bladder, prostate); oral (e.g., tonsils, dental, pharynx); neurosurgical (e.g., through skull drilled holes); dermatologic (e.g. local topical chemotherapy or chemical cautery).
[0060] For a device that is placed in a body cavity (such as an endoscopic, laparoscopic, or laryngoscopic device), the assembly may reside along a rigid or flexible/articulating shaft, with the piezoelectric actuator and the ampoule positioned distally so that it enters the body cavity, and power source positioned proximally and remain outside the body cavity, while the electrical current courses through the rigid or flexible shaft or flexible arm of the instrument to activate the piezoelectric actuator. In one embodiment, the ampoule resides next to the distal aspect of the light source and camera lens (e.g., adjacent to where the light arises out of the shaft and the camera lens is located). Alternatively, the assembly has no light source or camera and these elements are provided on a separate instrument. In another embodiment, the ampoule and piezoelectric actuator may remain on the proximal size of the shaft, such that the fluid being dispenses from the aperture courses through the length of the shaft and exits the distal end or tip of the shaft. The length of the rigid or flexible/articulating arm would differ in length and caliber/diameter depending on the application (e.g., relatively longer for laparoscopic, endoscopic, and gastroenterologic applications; relatively shorter for otologic applications; and intermediate for others).
[0061] The dispensing devices may advantageously utilize a disposable, removable, or separable drug or fluid package while desirably retaining the piezoelectric actuator or transducer for subsequent further uses, thereby providing an economical and cost effective approach with reuse of the piezoelectric actuator or transducer for further operation. Hence, in any of the embodiments described, the assembly may utilize a reusable actuator and/or housing with an ampoule which is separate or separable and implemented as a disposable or reusable ampoule. Alternatively, in any of the embodiments, the actuator and/or housing may be integrated with the ampoule in which case the entire assembly may be fully disposable or reusable. Various components of the assembly may be optionally reusable or disposable and implementation of such components is not intended to be limiting.
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[0063] The piezoelectric actuator assembly (1010) may generally comprise a piezoelectric clamping actuator (1014) which is configured to clamp or engage at least partially around the circumference of the first portion (1021) and adjacent to the one or more apertures (1023). Hence, the clamping actuator may have at least two opposed jaw members (1016A) and (1016B) which are designed to support and engage the first portion (1021) in a receiving channel (1011) defined between the jaw members (1016A), (1016B) via a secure engagement such as an interference fit, as shown in
[0064] As shown, primary oscillations may be imparted by the jaw members (1016A), (1016B) to the first portion (1021) along a first direction (1030) such that a secondary oscillation is induced in the first portion (1021) along a second direction (1032) which is perpendicular to the first direction (1030). The primary and secondary oscillations may thus force the ejection of fluid (1024) retained within the first portion (1021) from the one or more apertures (1023) such that the emitted fluid (1024) may be ejected in a stream of individual droplets or as a continuous stream of fluid depending, e.g., upon the frequency of the oscillations. The emitted fluid (1024) may be ejected from the one or more apertures (1023) in a direction that is normal to a longitudinal axis of the assembly (1000) such that an initial angle of the fluid (1024) relative to the first portion (1021) is perpendicular relative to one another. Alternatively, the fluid (1024) may be emitted at some predetermined angle relative to the first portion (1021). In yet another alternative, multiple fluid streams may be emitted from different apertures simultaneously or sequentially which may each be at uniform angles or at angles different from one another, e.g., for emitting fluid streams at different regions of the eye when the assembly (1000) is maintained in a stationary position relative to the subject's eye.
[0065] Generally, the oscillation amplitude of the jaw members (1016A), (1016B) may be less than, e.g., 2 microns. As the fluid is emitted from the first portion (1021), the fluid retained within the second portion (1022) may provide for a continuous flow of the fluid into the first portion (1021) during use, where the fluid may then be emitted from the first portion (1021) in a continuous or discontinuous fluid stream. The first portion (1021) of the ampoule (1020) may be inserted into the piezoelectric receiving channel (1011) by a relatively light force, typically less than 10 Newton in some variations and less than 5 Newton in other variations.
[0066] Referring now to
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[0068] In fabricating the ampoule (1020), the first portion (1021) and second portion (1022) may be constructed as separate components which are attached to one another or they may be constructed as a single, integrated structure. They may be made from one and the same material, or two different materials with differing material properties. For instance, the first portion (1021) may be made from a relatively more rigid material while the second portion made from a relatively more flexible material. The first (1021) and second (1022) portions may engage with each other in a variety of ways. For instance, a luer-lock mechanism maybe used to connect the first (1021) and second (1022) portions. In another example, a piercing mechanism or a screw-in mechanism may be used. In some mechanisms, fluid from the second portion (1022) may be released into the first portion (1021). One example for fabricating the ampoule (1020) is shown in the perspective view of
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[0070] With respect to the fabrication of the one or more apertures (1023), the formation of such small diameter apertures (e.g., on the order of 100 microns) may be relatively difficult because of behavior of thermoplastics when processed such as when laser machined. One variation may include the formation of a structure having the apertures separated from the ampoule fabrication so that the apertures may be formed with higher accuracy and precision. Such a structure may include the use of polyimide films which are stable over a wide range of temperatures such as Kapton? (E. I. du Pont de Nemours and Company). Other suitable polyimide materials may include, e.g., compositions of Kapton? and PTFE, synthetic polymers such as Nylon (E. I. du Pont de Nemours and Company), etc.
[0071] Referring to
[0072] In other variations where multiple apertures are utilized for dispensing, each of the apertures may be configured to preserve the uniqueness of an individual stream rather than forming a mist. Factors such as aperture size and spacing between the apertures may be adjusted accordingly to maintain the formation of the individual streams of fluid and to minimize or inhibit the merging or conflation of the individual fluid streams. For instance, apertures each having a relatively larger size, e.g., 80-100 microns, may allow for both relatively shorter pulse durations to deliver an equivalent volume of fluid. Furthermore, apertures having such a size may also allow for the use of fluids having a relatively higher viscosity such as artificial tears which are generally comprised of methylcellulose or carboxy-methylcellulose, hyaluronic acid derivatives or other hydrogels which would otherwise block or clog smaller sized apertures in the range of, e.g., 10-12 microns.
[0073] The fluid or fluids which may be used with the dispensing device may vary to include any number of agents depending upon, e.g., the treatment, the region of the body where the fluid is applied, etc. Examples of various fluids or agents which can be used may include (but are not limited to), e.g., anti-infectives (including but not limited to antibiotics, antivirals, etc.); anti-inflammatories (including but not limited to steroids and non-steroidal anti-inflammatory drugs (NSAIDS), etc.); anti-allergy (including but not limited to anti-histamines and mast cell stabilizers, etc.); anti-fungals; vasoconstrictors; mydriatic (pupil dilating) agents; miotic agents (pupil constricting agents); biologics (e.g. proteins, engineered proteins, etc.); small molecules; anesthetics; analgesics; intraocular pressure lowering agents (including but not limited to prostaglandin analogs, ROK inhibitors, beta blockers, carbonic anhydrase inhibitors, and alpha agonists, etc.); lubricants (including but not limited to saline, polymer solutions, proteoglycans, glycosaminoglycans, carbohydrates, etc.); iodine derivatives; etc. and/or various combinations thereof. Additional drugs and agents which may be utilized with the devices described may include any number of the agents disclosed in further detail in U.S. Pub. 2017/0344714 and U.S. Pat. No. 9,087,145 which are each incorporated herein by reference and for any purpose.
[0074] The dispensing device assembly (1000) including the ampoule (1020) and actuator assembly (1010) may be controlled via a controller which may include a platform or substrate upon which the actuator assembly (1010) may be positioned.
[0075] As previously described, the piezoelectric clamp (1014) may include the first piezoceramic plate (1012) bonded to the second piezoceramic plate (1013) where the first piezoceramic plate (1012) may be mounted on to the PCB (1005) along the piezo mounting section (1005P) and the clamp (1014) may be structurally bonded to the face of the second piezoelectric plate (1013). Both piezoceramic plates (1012) and (1013) may be aligned relative to each other and the combination of the piezoceramic plates (1012) and (1013) and the PCB (1005) may form a laminate which known as bimorph bender and which oscillates in a bending mode thereby causing oscillator clamping action on clamp (1014) electrically configure to oscillate in a bending mode, as described herein, so that the droplets or stream of fluid (1024) are ejected from the one or more apertures (1023).
[0076] In another variation, the first piezoceramic plate (1012) may be mounted on a first or back side of the PCB (1005) and the second piezoceramic plate (1013) may be mounted on a second or front side of the PCB (1005) so that the PCB (1005) is sandwiched between the respective plates (1012), (1013). The clamp (1014) may be mounted upon the second piezoceramic plate (1013), as previously described, and the plates (1012), (1013) may remain aligned relative to one another. In one variation, the piezoceramic plates (1012), (1013) may be soldered to the PCB (1005) during the solder reflow process in which all the electronic components (1051) are assembled. In this variation, the PCB (1005) functions as a passive layer and collectively forms the bimorph bender, as shown in the side and detailed side views of
[0077] The piezo mounting section (1005P) of the PCB (1005) may be at least partially isolated from the circuit section (1005C) by one or more cutouts. Referring now to the front view of
[0078] As described herein, the fluid ejection device may include an optical alignment mechanism which helps to align or target the one or more apertures to the ocular surface or to the area of the lower conjunctiva prior to actuation to ensure that the entire dose reaches the surface of the eye. For instance,
[0079] Prior to ejecting the fluid, the user may align the eye (1060) to be treated with the alignment mechanism (1064) so that the device is brought to an alignment with the optical axis (1062) of the eye (1060) to be treated or the center of the pupil. Proper alignment with the optical axis (1062) may accordingly position the one or more apertures (1023) at a predetermined small offset (D) relative to the optical axis (1062) as shown, e.g., 4 to 12 mm, depending on the preset offset (D). When the device is actuated, a stream of fluid (e.g., a continuous stream or discontinuous stream of droplets) will reach the targeted surface of the eye (1060) or the conjunctival tissue and deposit fluid at the above mentioned offset (D) from the pupil.
[0080] In yet another alternative embodiment of an actuator (2000), a transducer assembly configured to oscillate a disposable drug ampoule (2015) to dispense a fluid from the ampoule is illustrated in the exploded perspective view of
[0081] The junction (2003) may project radially from the mounting section (2002) to transition and form the elongate section (2001), as mentioned above, which further extends longitudinally and symmetrically about the longitudinal axis (2005) to terminate at a flattened interface surface (2012) which is formed perpendicularly relative to the axis (2005). The entire assembly (2001), (2002), (2003) may be formed of a thermoplastic material preferably with modulus of elasticity that is greater than, e.g., 3 GPa, such as acrylic, Acrylonitrile butadiene styrene (ABS), polyaryletherketone (Peek), etc. The assembly may be optionally formed (e.g., machined, cast, etc.) of a metal as well.
[0082] The transducer mounting section (2002) may be formed with flattened mounting surfaces (2004A) and (2004B) which are aligned symmetrically and in parallel relative to one another and relative to a longitudinal axis (2005) of the transducer assembly (2000). The piezoelectric plates (2006A) and (2006B) may be similarly or identically sized with one another and are mounted on opposite sides from one another. The mounting section (2002) may further include one or more mounting projections (2007) which extend from one or both sides of the section (2002) to facilitate securement of the assembly (2000) when in use.
[0083] The mounting arrangement of the piezoelectric plates (2006A) and (2006B) is advantageous since the transducer assembly (2000) can be made of a thermoplastic material which can optionally provide for a relatively low-cost disposable product. Conventional longitudinal transducers, such as those described in U.S. Pat. Nos. 4,655,393; 4,352,459; and U.S. Pat. Pub. 2010/44460 are typically made of a metal such as aluminum or stainless steel. Each of these references is incorporated herein by reference in its entirety and for any purpose herein. These transducers often have a clamping feature which clamps the piezoelectric plates to the end face of the transducer shaft. i.e., the planer surface of the piezoelectric plate is perpendicular to the axis of the transducer, and such arrangements have the transducers incorporate a clamping screw to secure the piezoelectric plates. However, it has been found that a thermoplastic material under a clamping stress tends to creep over time and consequently the preload force is relaxed and the function of the transducer deteriorates over time. Hence, the piezoelectric plates (2006A) and (2006B) may be simply adhered to their respective mounting surfaces (2004A) and (2004B) via an adhesive rather than using a clamping force provided that any discontinuities in the interface between the plates (2006A) and (2006B) and the surfaces (2004A) and (2004B) are minimized. The advantage of using a plastic transducer assembly may be a significant reduction in manufacturing costs since the plastic can be molded to any desirable shape very inexpensively and entirely removes the need for clamping of the plates (2006A), (2006B).
[0084] The elongate section (2001) may extend and form a tubular member which defines a uniform wall thickness, as shown. The section (2001) may be partially hollow and define a lumen (2014) as it transitions from the mounting section (2002) and junction (2003). While the elongate section (2001) shown may be formed as a tubular section, other cross-sectional shapes may be used as well, e.g., elliptical, octagonal, hexagonal, pentagonal, rectangular, etc. and the length of the section (2001) may range anywhere from, e.g., 1 to 10 cm. However, when the section (2001) is formed as a tubular member, this cross-sectional shape may be optimal for transferring vibrations from the piezoelectric plates (2006A) and (2006B) and through the length of the section (2001).
[0085] An ampoule mounting element (2008) may be configured to be mounted upon a distal end of the elongate section (2001) such that a first proximal side (2011) of the element (2008) contacts against and/or over the interface surface (2012) and a second distal side (2010) of the element (2008) is presented for interfacing against the ampoule (2015). The element (2008) may further define an ampoule engagement feature (2009) for coupling with the ampoule (2015). In one particular embodiment, the element (2008) may be formed into a cup-shaped member that is connected via the proximal side (2011) to the end of the elongate member (2001). An inner diameter of the cup-shaped configuration may engage securely over the distal end of the elongate section (2001), e.g., via an interference fit or any other securement mechanism. The ampoule engagement feature (2009), in this embodiment, may be formed as a threaded opening which is aligned with the longitudinal axis (2005).
[0086] Turning now to the ampoule (2015), a proximal end of the ampoule (2015) may be formed as an engagement rod (2017) which extends proximally from the body (2016) of the ampoule (2015). The rod (2017) may be threaded allowing for an optionally threaded engagement with the ampoule engagement feature (2009) of the ampoule mounting element (2008). This may allow for the secure threaded engagement of the ampoule (2015) to the mounting element (2008) and the ready removal and replacement of the ampule (2015) from the assembly (2000), e.g., for replacement when the ampoule (2015) is emptied after use. Other embodiments of the ampoule may utilize other attachment features rather than a rod (2017), e.g., frictional fitting, magnetic coupling, etc.
[0087] The ampoule (2015) may further include a distal tapered section (2018) which narrows from the body (2016) to a distal end defining an opening (2019) through which fluid or agent contained within the ampoule (2015) may be dispensed during use of the assembly (2000). The reservoir volume of the ampoule (2015) may also vary anywhere from, e.g., 0.2 ml to 5 ml or more preferably 0.5 ml to 1.5 ml, although other volumes may be sized accordingly.
[0088]
[0089]
[0090] During use and with reference to
[0091] Because the ampoule mounting element (2008) is securely attached to the distal end of the elongate section (2001), the face of element (2008) may be forced to resonate substantially at the same resonant frequency of the elongate section (2001). At its natural frequency, the face of the element (2008) may vibrate in a bending mode such that the amplitude near the circumference of its annular opening (2009) is the highest over the element (2008) as indicated by the vibrational direction (2042) and phantom lines (2044) which indicate the displacement movement of the element (2008) relative to the elongate section (2001).
[0092] Advantageously, the ampoule may be attached at the opening (2009) via rod (2017) such that the oscillation (2042) at its highest amplitude is transmitted to the body (2016) of the ampoule resulting in the corresponding oscillation (2043) of the ampoule body (2016). Consequently, the fluid contained within the ampoule (2015) may be ejected out of the ampoule body (2016) and through the aperture (2019) into a stream (2045) of fluid, as shown in the perspective view of
[0093]
[0094] In yet another embodiment of the transducer assembly,
[0095] The bimorph actuator (3010) may comprise a laminate of one passive plate (3011) and two active piezo-ceramic plates (3012), (3013) configured such that the passive plate (3011) is laid in between the two piezo-ceramic plates (3012), (3013), one piezo-ceramic plate on each opposite side of the passive plate. The faces of the passive plates (3011A) and (3011B) may be attached or bonded to a face of one piezo-ceramic plate (3012) and to a face of one piezo-ceramic plate (3013), respectively, while the passive plate itself is extended as a cantilever plate from the ampoule holder (3020) via a junction interface (3025). Oscillation of piezo-ceramic plates (3012), (3013) are transmitted to the passive plate (3011) and to the ampoule holder via a connection therebetween, as will be explained further below.
[0096] In one embodiment, both piezo-ceramic plates (3012), (3013) may have the same piezo poling orientation as indicated by the arrows (3012P), (3013P) relative to their attachment to the passive plate and the same electrical connection with respect to the piezo poling such that when the two piezo-ceramic plates receives alternating voltage signal, accordingly, bimorph actuator (3010) expands and contracts along its lateral dimension and producing oscillation amplitude in the lateral directions as indicated by arrows (3011L). Lateral oscillations are transmitted to the ampoule holder (3020) via the attachment between the structural plate and the ampoule holder (3020).
[0097] This embodiment, similar to the piezo-ceramic plate configuration described above, illustrates the use of two symmetrically attached plates; however, in other embodiments, fewer than two or greater than two plates may be utilized. Additionally, it is within the scope of this description that other variations of the plates may be used having different configurations, as desired.
[0098] The frequency of the alternating electrical signal is substantially equal to the resonance frequency of the dispensing device at its lateral or longitudinal mode. In one embodiment, the length of the bimorph actuator (3010) may be, e.g., 15 mm, and its width may be, e.g., 10 mm. The passive plate may be an integral part to the ampoule holder wherein the overall length of the piezoelectric actuator (3010) may be, e.g., 35 mm, and the diameter of the ampoule holder may be, e.g., 8-12 mm. The resonance frequency of the piezoelectric actuator may be, e.g., 22.5 kHz. The passive plate (3011) may extend for the ampoule holder perpendicularly as a cantilever plate or optionally the passive plate may extend at an angle relative to the longitudinal axis (3026) of the ampoule holder.
[0099] The ampoule (3030) that can be readily attached to or detached from ampoule holder (3020) as will explain further below. Referring to
[0100] The ampoule (3030) may further include a circular array of protrusions or bumps (3035) arranged around the circumference of the ampoule (3030) at a small distance from the face of flange (3034), typically from, e.g., 1 to 4 mm. The protrusions (3035) may be used as anchoring points to securely retain the ampoule (3030) inside the ampoule holder (3020). These protrusions or bumps may also be shaped in any number of different configurations as well as arranged in any number of patterns so long as the protrusions (3035) securely retain the ampoule (3030) within the ampoule holder (3020).
[0101] Ampoule holder (3020) includes an end-face (3021) and an internal bore (3022) having a diameter that is slightly larger than the diameter of the ampoule. The internal bore may have a hump or restricting feature (3023) around its internal diameter that may be shaped, e.g., like a rounded circumferential protuberance. When ampoule (3030) is inserted into the ampoule holder (3020), the flange (3034) may engage with the end-face (3021) as protrusions (3035) partially cross over hump (3023). In the way, the ampoule (3030) may be clamped securely to the end face of the ampoule holder and ultrasonic oscillation may be therefore transmitted effectively.
[0102]
[0103] As illustrated, actuator (3010) may include one or two piezo-ceramic plates and one or two passive plates. In the present embodiment, the passive plates may be made of thermoplastic elastomers, e.g., acrylic or PEEK. Elastomers have a relatively low modulus of elasticity, approximately 3 GPa, relative to the elasticity of the piezo-ceramic material having a modulus of elasticity of approximately 60 GPa. This subsequently enables the use of relatively thinner piezo-electric plates to generate cycles of structural deformation. Thinner piezo-ceramic plates require proportionally lower input voltages which substantially eliminates the need to include a voltage boosting circuitry such as DC-DC converter. Thus making lateral longitudinal transducers from thermoplastic as described reduces the cost of the electronic circuit and subsequently the product itself. The lateral or longitudinal transducer and ampoule holder may be made from a thermoplastic by, e.g., injection molding processes, with thermoplastics having a modulus of elasticity that is lower than, e.g., 4 GPa, and more preferably between, e.g., 3 GPa to 4 GPa, while the thickness of the piezo-ceramic plate may be less than, e.g., 1 mm, and preferably less than, e.g., 0.5 mm.
[0104] Referring now to
[0105]
[0106]
[0107] This gap (3033i) creates an annular capillary passage that draws fluid from the ampoule (3030) to the aperture (3037). Insert (3030i) may include one or more openings (3034i) around its circumference which allows fluid to flow from the center of the ampoule (3030) through the openings (3034i) to the annular capillary gap (3033i) and to the aperture (3037). The internal surfaces of the annular capillary gap (3033i) may be treated with a hydrophilic coating such as HYDROPHILIC COATING FORMULA B (Coating 2Go, Carlisle, Mass.).
[0108] Hence, because the fluid is drawn directly to the aperture (3037) via capillary action through the gap (3033i), there is no need for any pumping mechanism. Rather, the capillary action ensures that the movement of fluid to the aperture is independent of the orientation that the ampoule (3030) is held by the user and is further independent of the fluid level contained within the ampoule (3030), i.e., dispensing of the fluid from the ampoule (3030) is independent of gravity. Conventional fluid reservoirs typically require some active pumping mechanism to draw a fluid for dispensing particularly when the fluid level drops relative to the aperture such as when a user holds the fluid reservoir at an extreme angle or when the fluid runs low.
[0109] Regardless of the orientation of the ampoule (3030) or the amount of fluid remaining within the ampoule (3030), e.g., when the fluid runs low, the capillary action created between the ampoule (3030) and insert (3033i) ensures that the fluid is drawn to the aperture (3037).
[0110] The ampoule (3030) and insert (3030i) can be made of a thermo-plastic polymer such as polypropylene or polyethylene and preferably hydrophilic polymer or a polymer which has its surfaces modified to have hydrophilic properties. Insert (3030i) can be made from hydrophilic porous polypropylene (Porex Corporation, Fairburn, Ga.). The ampoule may be further provided with a venting hole (3038) which allows for equalization of the pressure as fluid is dispensed from the ampoule. As illustrated, the ampoule (3030) may be provided with a cup or cap (3040) which closes the opening of the aperture (3033) when the device is not in use. The cup or cap (3040) may be attached to the ampoule body by, e.g., thread engagement (3036) (3041) or other engagement mechanism, and seal the tapered end (3032) of the ampoule against tapered hole (3042) in the cup or cap (3040).
[0111] When the cup or cap (3040) is fully engaged with ampoule (3030), the aperture (3033) and venting hole (3038) are both sealed. The diameter of venting hole (3038) may range from, e.g., 0.1 to 0.6 mm, which is sufficiently small to prevent outflow or spillage of fluid from the ampoule. The angular dimension (Ang) of conical section (3036) may range from, e.g., 30 to 60 degrees, while the wall thickness (Thk) of the ampoule may range from, e.g., 0.3 to 1 mm. The diameter (D) of the ampoule is generally between, e.g., 4 to 10 mm, while its length (L) may vary based on the desired liquid volume to be stored in the ampoule, liquid volume is generally between, e.g., 0.5 to 3 mL. The ampoule assembly (3000) may further include an end cup (3030c) which seals the ampoule following aseptic drug filling.
[0112] Referring now to
[0113]
[0114] In some embodiments, the fluid ejection device may include an optical apparatus to align or target the dispensing aperture to the ocular surface or to the area of the lower conjunctiva prior to actuation, as further described herein. Such alignment assures that the entire dose reaches the surface of the eye. Referring now to
[0115] The dispensing nozzle (3033) may be positioned at a predetermined small offset (D) relative to the optical axis of the tube (3084), e.g., 4 to 12 mm, depending on the preset offset (D). When the device is actuated, a stream of fluid (e.g., a continuous stream or discontinuous stream of droplets) will reach the targeted surface of the eye or the conjunctival tissue and deposit fluid at the above mentioned offset from the pupil.
[0116] The optical tube (3080) may have a length of, e.g., 20, 30, or 40 mm, while its internal diameter ranges between, e.g., 1 to 5 mm. The internal surfaces of the tube may be optionally coated with optically-black non-reflective coating.
[0117] The applications of the disclosed invention discussed above are not limited to the embodiments described, but may include any number of other applications and uses. Modification of the above-described methods and devices for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the arts are intended to be within the scope of this disclosure. Moreover, various combinations of aspects between examples are also contemplated and are considered to be within the scope of this disclosure as well.