Small-scale capacitive ultrasound transducer devices and methods
Inventors
Moehring, Mark A. • KREINDLER, Daniel • Gates, George A. • Cameron, Caitlin E.
Assignees
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Publication Number
US-11850091-B2
Publication Date
2023-12-26
Expiration Date
Abstract
An ultrasound transducer may include: a plurality of capacitive ultrasound transducer elements; and a base having a largest dimension sized and shaped to be disposed with an external ear canal, wherein the plurality of capacitive ultrasound transducers is mounted on the base. Each capacitive ultrasound transducer element and the ultrasound transducer are specifically constructed to achieve select desired performance characteristics. The ultrasound transducer may have an angular beam spread through a gaseous medium of greater than 15 degrees and an attenuation loss through the gaseous medium of greater than 10 dB measured at a distance 12.5 mm to 25 mm along a primary transmission axis of the ultrasound transducer. The ultrasound transducer may be particularly useful for characterizing fluid behind an ear drum to diagnose otitis media.
Core Innovation
The invention relates to an ultrasound transducer that includes a plurality of capacitive ultrasound transducer elements mounted on a base. The base has a largest dimension sized and shaped to be disposed with an external ear canal, and the capacitive ultrasound transducer elements are configured to form an ultrasound waveform suitable for transmission through a gaseous medium.
The plurality of capacitive ultrasound transducer elements form an ultrasound waveform having an angular beam spread through a gaseous medium greater than 15 degrees. The waveform also provides an attenuation loss through the gaseous medium greater than 10 dB measured at a distance from 12.5 mm to 25 mm along a primary transmission axis.
The document describes using ultrasound transmission and reflected waveform perturbations associated with a pneumatic challenge to classify or estimate physical properties of fluid behind the tympanic membrane. In that context, the system provides membrane motion data and ringdown characteristics that are correlated with effusion viscosity or type and with elasticity-related characterization.
The document also outlines cMUT element construction and micro-geometry features, including electrodes and a cavity height, together with working-surface openings configured as release holes or release slits. The element layout is described using hexagonal closest packing, and the document associates ringdown damping and frequency behavior with effusion viscosity correlation.
Claims Coverage
The provided claims include one independent claim and dependent claims that refine the transducer with quantitative structural and actuation constraints and array and micro-geometry constraints.
Capacitive ultrasound transducer elements on ear-canal base
A plurality of capacitive ultrasound transducer elements mounted on a base having a largest dimension sized and shaped to be disposed with an external ear canal.
Angular beam spread and gaseous-medium attenuation over defined distance
The plurality of capacitive ultrasound transducer elements is configured to form an ultrasound waveform having an angular beam spread through a gaseous medium greater than 15 degrees and an attenuation loss through the gaseous medium greater than 10 dB measured at a distance from 12.5 mm to 25 mm along a primary transmission axis.
Small base size for external ear canal disposition
The base has a largest dimension less than 3 mm.
Resonant frequency range of capacitive transducer elements
The plurality of capacitive ultrasound transducer elements has a resonant frequency between 1.0 MHz and 3.0 MHz.
Hexagonal closest packing array on the base
The plurality of capacitive ultrasound transducer elements is arranged on the base using a hexagonal closest packing structure.
Pull-in voltage threshold
The ultrasound transducer has an 80% pull-in voltage of less than 85 V.
Release-slit working-surface micro-geometry
The ultrasound transducer includes openings configured as release slits having a slit-width of at least 0.4 microns and a spring length of at least 2 microns.
The core inventive coverage is an air-coupled ultrasound transducer using multiple capacitive ultrasound transducer elements mounted on a base sized for an external ear canal, with the elements forming an ultrasound waveform characterized by angular beam spread and gaseous-medium attenuation over 12.5 mm to 25 mm along a primary transmission axis. Dependent claims further narrow the invention by specifying base size, resonant frequency range, array packing, pull-in voltage, and working-surface release-slit micro-geometry dimensions.
Stated Advantages
Documented Applications
No documented applications found
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