The present invention provides an acoustic transducer, or an array of such transducers, formed on a single integrated circuit chip, and a method of making the same, in which there is included an array of acoustic transducers, each capable of detecting an acoustic signal and generating a transducer signal, and including a first and second electrode with a void region disposed between the first and second electrode, and at least one signal line associated with one of the first and second electrodes. Disposed below the array of acoustic transducers is a plurality of amplifiers and other circuit components, such that each of the plurality of amplifiers is coupled to one of the signal lines associated with one of the acoustic transducers and is capable of amplifying the associated transducer signal to obtain an amplified transducer signal on an amplifier output signal line.
A capacitive micromachined ultrasonic transducer (cMUT) is constituted by a plurality of transducer elements comprising plural transducer cells that are mutually connected in parallel and comprises: a silicon substrate; a bottom electrode placed on the top surface of the silicon substrate; an upper electrode placed opposite to the bottom electrode and apart therefrom by a prescribed air or vacuum; a membrane for supporting the bottom electrode; and a membrane supporting part for supporting the membrane, wherein the cMUT comprises a third electrode which has an electrical continuity to the bottom electrode and which corresponds to either one of the transducer cells of a prescribed number of the transducer subelement or of the transducer elements, and a fourth electrode which is a ground electrode electrically connected to the bottom electrode.
The present invention provides a method of packaging surface microfabricated transducers such that electrical connections, protection, and relevant environmental exposure are realized prior to their separation into discrete components. The packaging method also isolates elements of array transducers. Post processing of wafers consisting of transducers only on the top few microns of the wafer surface can be used to create a wafer scale packaging solution. By spinning or otherwise depositing polymeric and metallic thin and thick films, and by lithographically defining apertures and patterns on such films, transducers can be fully packaged prior to the final dicing steps that would separate the packaged transducers from each other. In the case of microfabricated ultrasonic transducers, such packaging layers can also enable flexible transducers and eliminate or curtail the acoustic cross-coupling that can occur between array elements.
The present invention relates to medical devices; in particular, the present invention provides devices and methods for sensing thickness of cardiac tissue and the like so that medical procedures may be efficiently performed through and/or upon a discrete location having suitable tissue thickness. The invention includes an elongated resilient dilator apparatus having an ultrasound transceiver coupled thereto. When the ultrasound transceiver is disposed proximate a region of relatively thin tissue, such as a latent Fossa Ovalis valve, a clinician receives a signal. The clinician may then proceed with enhanced confidence to pierce the relatively thin tissue. Thus, in the case of a transseptal procedure, the clinician gains access to the left atrial chamber from the right atrial chamber.
A single chip transducer apparatus that includes on-chip electronic circuitry which, when connected properly to a two-dimensional matrix of ultrasonic transducer elements, provides enough information to an external imaging system to form three-dimensional images of the subject of interest. In a preferred embodiment, the circuitry provides an amplifier for each transducer element, and then conditions the output of the amplifier in several ways. In one embodiment of the invention, the elements' analog voltages are stored in a sample and hold circuit, and time multiplexed into a high speed line driver that sends many elements data down the interconnect to the system's high speed Analog to Digital converters. In another embodiment, the gain of the amplifiers can be controlled in time to provide aperture translation and time based expansion for translating and focusing image slices in the elevation direction.
A high density, exceptionally complex and compact ultrasound transducer array using multi-layer structures composed of active integrated circuit devices on various substrates and passive devices. Electrically conducting interconnections between substrates are implemented with micro-vias configured with conductors extending through the substrates, permitting the use of divided or different integrated circuit technologies arranged and/or isolated within different integrated circuit substrates or layers of the ultrasound transducer assembly. The various layers may be assembled with solders of respectively lower reflow temperatures, to permit testing of selected layers and circuits prior to completion.
