Systems and methods for driving sealed nebulizers

Abstract

Various methods, devices, and systems are described for aerosolizing a liquid. Embodiments may include sealing the liquid within a reservoir. An output waveform signal may be generated. A nebulizer element may be vibrated to aerosolize the liquid. A negative pressure may be produced within the reservoir as the liquid is aerosolized. The output waveform signal may cause the nebulizer element to vibrate. Embodiments may involve determining a phase shift between a current of the output waveform signal and a voltage of the output waveform signal. Also, embodiments may involve adjusting a frequency of the output waveform signal at least partially based on the phase shift. Further, embodiments may involve adjusting the voltage of the output waveform signal at least partially based on the frequency of the output waveform signal.

1 . (canceled) 
     
     
         2 . A method for operating a nebulizer, the method comprising:
 driving an element of the nebulizer using an electrical signal to cause the element to atomize a liquid;   measuring a phase shift between a voltage and a current of the electrical signal that drives the element of the nebulizer;   based at least in part on the measured phase shift of the electrical signal, determining a frequency at which to drive the element of the nebulizer;   calculating a voltage magnitude for the electrical signal based on the determined frequency, wherein the calculated voltage magnitude is used to maintain consistent droplet sizing of the liquid being atomized; and   causing the electrical signal driving the element of the nebulizer to have the calculated voltage magnitude and the determined frequency.   
     
     
         3 . The method for operating the nebulizer of  claim 2 , wherein calculating the voltage magnitude for the electrical signal is further based on a type of the liquid being atomized. 
     
     
         4 . The method for operating the nebulizer of  claim 2 , further comprising: adjusting the frequency of the electrical signal to maintain a substantially constant phase shift between the voltage and current of the electrical signal. 
     
     
         5 . The method for operating the nebulizer of  claim 2 , wherein a reservoir that stores liquid to be atomized by the element causes a resonant frequency to vary as the liquid is drained from the reservoir. 
     
     
         6 . The method for operating the nebulizer of  claim 5 , further comprising:
 draining the liquid from the liquid reservoir to supply the element of nebulizer with the liquid, wherein the liquid reservoir is sealed to allow a pressure within the liquid reservoir to decrease as the liquid is drained.   
     
     
         7 . A system for driving an element of a nebulizer, the system comprising:
 an amplifier that generates an output waveform signal, the output waveform signal comprising an output frequency, an output current, and an output voltage, wherein the output waveform signal drives the element of the nebulizer at the output frequency;   a phase shift detector component that measures a phase shift between the output current and the output voltage of the output waveform signal;   a frequency tracker component that generates a waveform signal of a variable frequency that is input to the amplifier, wherein the waveform signal controls the output frequency and the variable frequency is adjusted based on the phase shift of the output waveform signal measured by the phase shift detector component; and   a voltage profile component that controls a magnitude of the output voltage of the output waveform signal based on the frequency of the waveform signal generated by the frequency tracker wherein the magnitude of the output voltage is used to maintain consistent droplet sizing of the liquid being atomized.   
     
     
         8 . The system for driving the element of the nebulizer of  claim 7 , wherein the voltage profile component that controls the magnitude of the output voltage of the output waveform signal further controls the magnitude of the output voltage based on a type of liquid being atomized. 
     
     
         9 . The system for driving the element of the nebulizer of  claim 7 , wherein the voltage profile component calculates the magnitude based on the frequency of the waveform signal generated by the frequency tracker. 
     
     
         10 . The system for driving the element of the nebulizer of  claim 7 , the system further comprising a liquid reservoir that causes a resonant frequency of the element of the nebulizer to vary as liquid is drained from the liquid reservoir. 
     
     
         11 . The system for driving the element of the nebulizer of  claim 10 , wherein the liquid reservoir is configured to be sealed such that a negative pressure, as compared to an external environment, develops as the liquid is drained from the sealed liquid reservoir for atomization by the element of the nebulizer. 
     
     
         12 . The system for driving the element of the nebulizer of  claim 7 , wherein the driver device is coupled with the nebulizer as part of a handheld unit. 
     
     
         13 . The system for driving the element of the nebulizer of  claim 7 , wherein the frequency tracker component adjusts the frequency of the output waveform signal to maintain a substantially constant phase shift between the voltage and current of the output waveform signal. 
     
     
         14 . A system for atomizing a liquid, the system comprising:
 a liquid reservoir for holding the liquid that is to be atomized;   a nebulizer comprising an element having a plurality of apertures, wherein:
 the element is configured to vibrate to atomize the liquid drained from the liquid reservoir wherein the element is driven by an output waveform signal; and 
 a pressure within the liquid reservoir changes as liquid stored in the liquid reservoir is drained and atomized by the element; and 
   a driver unit, comprising:
 a phase shift detector component for measuring a phase shift between a current of the output waveform signal and a voltage of the output waveform signal; 
 a frequency tracker component that generates a waveform that adjusts the frequency of the output waveform signal, wherein the frequency is adjusted based on the phase shift determined by the phase shift detector component; and 
 a voltage profile component that controls a magnitude of the voltage of the output waveform signal based on the frequency of the waveform generated by the frequency tracker component wherein the magnitude of the voltage is used to maintain consistent droplet sizing of the liquid being atomized. 
   
     
     
         15 . The system of atomizing liquid of  claim 14 , wherein the voltage profile component that controls the magnitude of the voltage of the output waveform signal further bases the magnitude on a type of liquid being atomized. 
     
     
         16 . The system of atomizing liquid of  claim 14 , wherein the voltage profile component calculates the magnitude based on the frequency of the waveform generated by the frequency tracker component. 
     
     
         17 . The system for atomizing liquid of  claim 14 , wherein the liquid reservoir is configured to be sealed with the liquid inside such that a pressure within the liquid reservoir decreases when the liquid is drained for atomization. 
     
     
         18 . The system of atomizing liquid of  claim 14 , wherein the driver is coupled with the nebulizer in a handheld unit. 
     
     
         19 . The system of atomizing liquid of  claim 14 , wherein the driver further comprises an amplifier configured to generate the output electrical signal using signals from the frequency tracker component and the voltage profile component. 
     
     
         20 . The system of atomizing liquid of  claim 14 , wherein a processing unit of the driver unit is configured to compare the measured phase shift with a desired phase setpoint to determine a phase error value. 
     
     
         21 . The system of atomizing liquid of  claim 20 , wherein the processing unit of the driver unit is further configured to, based on the determined phase error value, store an indication of a current frequency being output by the frequency tracker component.