This disclosure relates to atomization of fluids, more particularly to hand-held atomizers for drug and therapeutics delivery.
The primary method for the delivery of eye drops has been an eye drop dispenser, also referred to as a droptainer. These small containers typically have an orifice with a controlled size that regulates how much liquid comes out when the container tips upside down.
However, many users find eye drops difficult to use and would welcome alternative methods to deliver materials to the eye. Additionally, since a droptainer delivers only a single drop as one large droplet, much of the volume of material delivered is lost. The delivered volume may only have 10% of the volume of the active material from the droptainer.
Spray delivery provides a method for the delivery of these drugs. Spray delivery can overcome many of the challenges associated with a droptainer since additional momentum imparted to the spray particles allows the delivery device to work at any angle relative to the eye. However, existing spray delivery systems have their own challenges. One approach, pneumatic atomization, may result in large globs of spray during the beginning of the stroke. Additionally, when non-Newtonian, extensionally hardening fluid is used a pneumatic actuator will produce a filament like stream of fluid, not a mist of small droplets. Ultrasonic and vibrating mesh technologies can produce a fine, small mist without large droplets but have extreme limitations on rheology and cannot process fluids at all that have even small amounts of extensionally hardening properties.
An embodiment is a hand-held dispenser to dispense fluid includes a casing to fit into a hand of a user, a nozzle in the casing to dispense a mist, a fluid reservoir contained in the casing to hold a fluid to be turned into the mist, a filament extension atomizer contained in the casing to generate the mist, an air source contained in the casing to provide air flow to direct the mist to the nozzle, a motor contained in the casing to operate the filament extension atomizer, an actuator positioned on the casing to activate the dispenser, a control circuit contained in the casing to receive a signal from the actuator and to send a signal to the motor to cause the motor to actuate, and a power source contained in the casing to provide power to the motor upon receive a signal from the control circuit.
An embodiment is a dispensing system having a hand-held dispenser to dispense fluid as a mist. The hand-held dispenser has a casing configured to fit into a hand of a user, a nozzle in the casing arranged to dispense a mist into an eye of the user, a fluid reservoir contained in the casing to hold a fluid to be turned into the mist, a filament extension atomizer contained in the casing to receive fluid from the reservoir and to generate the mist, an air source contained in the casing, the air source to provide air flow to direct the mist to the nozzle, a motor contained in the casing, the motor connected to the filament extension atomizer to operate the filament extension atomizer, an actuator positioned on the casing to allow the user to activate the dispenser, a control circuit contained in the casing, the control circuit electrically connected to the motor and the actuator to receive a signal from the actuator and to send a signal to the motor to cause the motor to actuate, a power source contained in the casing, the power source electrically connected to the control circuit and the motor to provide power to the motor upon receive a signal from the control circuit, and a dispenser connector. The system also includes a power connector with the dispenser connector to provide power to the power source in the dispenser.
The filament extension atomizer 18 receives a fluid from a fluid reservoir 16 and delivers a mist to the nozzle 14. The nozzle 14 may have a dimension selected to focus the spray on a target location of a specific size. For best results, the area is tightly controlled and as small as possible to minimize overspray, maximize delivery, and prevent undesirable contact with the skin. The fluid to be delivered may consist of some sort of therapeutic material, such as eye drops, antibiotic sprays for wounds, etc.
The fluid reservoir 16 contains the fluid. The reservoir may be refillable or replaceable, as will be discussed in more detail later. In addition, more than one reservoir may be present in the casing, with a selector knob or other means of choosing which fluid reservoir sends fluid to the filament extension atomizer. The reservoir may be pressurized, such as with air, or mechanical compression such as a spring. The liquid reservoir may interface with the filament extension atomizer and the other components of the system through a port, tube, valve, etc.
The filament extension atomizer generates a mist from the fluid under control of an electronic control circuit and powered by the motor/drive circuit 22. The air source 20 directs the mist from the filament extension atomizer to the nozzle. Since small particles (under 100 microns) are produced by the Filament Extension Atomizer, they will quickly lose momentum once they have exited the device. The air source could be an electronic air pump, a fan, a compressed container, or any other source of air volume. The air helps direct the spray towards the surface being treated and helps maximize delivery efficiency. The air speed and pressure should be minimized to maximize comfort. The choice of airflow speed and pressure may depend on the application area. For example, a close-range application, such as a range of less than 25 millimeters, requires low airspeeds to allow the maximum amount of material to reach the substrate in a small area. However, if the application uses a longer distance, the longer distance to the target will require more momentum and therefore higher air speeds. Air is activated through the use of a pump or a valve. A pump may be used if no stored air is used, in this case the pumping element is activated either through an electronic control or through the motion of the driving element to create pressure from the air. If an onboard air source is used, such as a compressed gas, the valve is actuated either through an electronic signal or the motion of the actuation drive unit to release the compressed air in a controlled manner.
The filament extension atomizer 18 converts the fluid to a mist by stretching the fluid between diverging surfaces to form filaments. The diverging surfaces cause the filaments to break up into droplets that form the mist. The filament extension atomizer may use many different types of diverging surfaces. The embodiments here employ two counter rotating rollers. As the surfaces of the rollers rotate away from each other, the fluid forms filaments that then extend to the point of breaking into a mist.
The filament extension atomizer runs under control of the motor 22. This may consist of an electric motor designed to operate at high speed, typically thousands to tens of thousands of revolutions per minute. The motor will couple to the filament extension atomizer through mechanical couplings. This could include belts, pulleys, gears, a shaft, or electrical or magnetic coupling. The filament extension atomizer may also include a gearing mechanism to drive the rollers or motors at different speeds.
The device operates when a user presses or otherwise activates the actuator 24. This may consist of a button or other actuator that causes a signal to be sent to the control electronics. For user convenience, the actuator 24 may reside in a position on the casing 12 such that the user can hold the dispenser and activate the actuator with the same hand. The button may have multiple positions or multiple sensing modes. For example, a button may initial be depressed slightly or detect contact through capacitive means to active the device's electronics or turn on some of the subsystems and then when the device is further depressed the system may dispense a dose. Alternatively, multiple sensing modes, such as capacitive and physical depressing can be used to allow two activation modes to be used.
Upon receiving a signal from the actuator, the electronic control circuitry causes the device to operate. The control circuit may control the charging of the battery or other power source 28, provide drive voltages to the motor, switch any pumps or valves, and provide user feedback and control. The electronic control circuitry may consist of a controller integrated circuit, a circuit board with the necessary components to manage the control, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a microcontroller, etc. The actuator may actuate components either simultaneously or in a specific order. In some embodiments, the air is turned on first, followed by a short delay, the motor is activated to turn on the rollers, after another short delay the pump is activated for a fixed period of time. When the pump has been deactivated, the motor is turned off, followed by a short delay, followed by the airflow.
The electronics may include a communications link to allow the dispenser to communicate with device external to the dispenser through common wireless protocols such as Bluetooth, WiFi, or other near-field communications. The battery 28 will typically consist of a rechargeable battery and may be charged by a cord, contacts, or a wireless inductive charging system.
The dispenser shown in
The fluid cartridge my contain multiple fluids simultaneously, separated by air or by a barrier of some kind, such as a film. As the device dispenses the fluid, it eventually exhausts all the therapeutic or drug fluid. The device will then reach the cleaning fluid and dispense cleaning fluid, cleaning the system. The user may be notified that is reaching the end of the useable fluid and cleaning fluid is about to be dispensed, by counting the number of doses dispensed from a cartridge or by detecting a change in the fluid, such as viscosity, optical opacity, or viscosity.
Additionally, a fluid cartridge may contain multiple chambers separated by a divider. The divider may be a film or a solid wall. A cartridge will multiple chambers will include multiple seal and puncture structures and the device itself may have multiple valves or pumps to accommodate the multiple fluids. In this manner, the system may select from multiple fluids to dispense. For example, if a treatment involves multiple drugs, the system may dispense them sequentially to the user. Alternatively, one chamber may be a cleaning solution that the user can choose to activate if the device needs to be cleaned.
The system may have multiple means for detecting information about the cartridges that have been loaded. A RFID or NFC tag can be placed on the cartridge in the form of a label or as a small component. The system electronics can be configured with electronics to read this data using the appropriate wireless protocols to detect information about the cartridge inserted. The information can include things like the material contained within the cartridge, the amount of fluid or doses, dose amount settings, settings for the FEA system, serial number, expiration date, or the recommended dose frequency for the user. The system can use this data to adjust settings of the airflow and the FEA spray system or provide information or prompts to the user to use the fluid at a certain frequency or time.
In addition to replaceable fluid cartridges, other components may be replaceable, including the filament extension atomizer rollers. These removable cartridges, referred to here as head cartridges, contain the rollers.
The rollers, in either the replaceable cartridge or not, have a similar size to the motor size. It is possible to utilize what is commonly referred to as a “hub motor” to combine the motor and roller subsystems. In this implementation the rotor is the roller and the stator is internal to the roller. The motor may consist of many different constructions, but a typical form would be a brushless DC motor with a permanent magnet (PM) rotor.
The rollers rotate at speeds like many fans and blowers and have a similar diameter. Generation of a pressure differential directly on the surface of the rollers can induce air flow useful for the filament extension atomizer. One embodiment includes an impeller feature directly onto the radial face of the roller to create tangential air flow as shown with the impeller 64 of
In this embodiment, the impeller pulls air in near the axis of rotation of the roller and blows it tangentially outwards in the radial direction. The filament extension atomizer may have additional features to direct the air both into the roller/blower and out of the tangential blades to create useful air flows.
The use of a motor may allow the system to track the cleanliness of the rollers. The solution may leave behind a sticky polymer residue which becomes especially thick at the nips, where the rollers meet. These areas may have enough sticky material to affect the operation of the motors. This can be used to detect over-current, although other methods could be used.
Cleaning the rollers may involve replacing the rollers, as in the head cartridge replacement discussed above at 78, the user can insert the roller into a cleaning/docking station to allow the rollers to be cleaned at 79, or the user could insert a cartridge of cleaning solution into the dispenser to clean the rollers with a cleaning solution.
A docking station may be used for other reasons, such as charging, storage, etc., but it can also be used to clean the dispenser.
In
It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
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Ghasem, G., Nasr, Andrew J. et al., Chapter 2. Background on Sprays and Their Production, Jan. 1, 2002, Industrial Sprays and Atomization: Design, Analysis and Applications, Springer, London, Pates 7-33. |
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Number | Date | Country | |
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20200093998 A1 | Mar 2020 | US |