Abstract: An electrodynamic compression driver is defined that contains a compression chamber assembly partially bounded by an annular diaphragm. The compression chamber assembly has an annular axisymmetric geometry with a single exit for acoustic radiation. The chamber geometry is further defined such that only the zero-hertz mode of acoustic coupling is supported, allowing the use of a lumped parameter model for analysis of the acoustic coupling of diaphragm and compression chamber. The lumped parameter model is integrated with eigenmode analysis of diaphragm modes and characterization of the cross-coupling between diaphragm and compression chamber. The result is more rapid computation of how to control mechanical modes in the annular diaphragm so that they benefit the compression driver's acoustic output. Embodiments of compression chamber and diaphragms with geometry that facilitate modal control are provided.

Abstract: A phase plug for an electrodynamic compression driver, including a compression chamber formed by an oscillating diaphragm and a boundary face of a phase plug assembly adjacent to the diaphragm, a singular acoustic exit defined by a termination of the phase plug assembly, one or more passageways which traverse through the phase plug assembly from the compression chamber to terminate at the acoustic exit, and an axis of rotation, defined within an interior of the phase plug assembly, that extends from the boundary face of the phase plug assembly at the compression chamber to the acoustic exit, where at least one of the passageways expands in cross sectional area between the respective entrance at the boundary face of the phase plug assembly, and the termination at the acoustic exit, while traversing through the phase plug, and where at least one of the internal passageways with the expanding cross section is rotated about the axis of rotation.

Abstract: A method—implemented in vitro—for the diagnosis and/or prognosis, preferably in the early stage, of benign or malignant neoplasms of the biliary tract is provided. The method is based on the selection and measurement of the hypermethylation levels of a genetic locus in samples of nucleic acids extracted from tumor tissues and from minimally and/or non-invasive matrices from patients with BTC and a relative comparison of the hypermethylation levels with levels of the same marker in non-tumor samples. A kit for carrying out the above method is also provided.

Abstract: A phase plug for an electrodynamic compression driver, including a compression chamber formed by an oscillating diaphragm and a boundary face of a phase plug assembly adjacent to the diaphragm, a singular acoustic exit defined by a termination of the phase plug assembly, one or more passageways which traverse through the phase plug assembly from the compression chamber to terminate at the acoustic exit, and an axis of rotation, defined within an interior of the phase plug assembly, that extends from the boundary face of the phase plug assembly at the compression chamber to the acoustic exit, where at least one of the passageways expands in cross sectional area between the respective entrance at the boundary face of the phase plug assembly, and the termination at the acoustic exit, while traversing through the phase plug, and where at least one of the internal passageways with the expanding cross section is rotated about the axis of rotation.

Abstract: An electrodynamic compression driver is defined that contains a compression chamber assembly partially bounded by an annular diaphragm. The compression chamber assembly has an annular axisymmetric geometry with a single exit for acoustic radiation. The chamber geometry is further defined such that only the zero-hertz mode of acoustic coupling is supported, allowing the use of a lumped parameter model for analysis of the acoustic coupling of diaphragm and compression chamber. The lumped parameter model is integrated with eigenmode analysis of diaphragm modes and characterization of the cross-coupling between diaphragm and compression chamber. The result is more rapid computation of how to control mechanical modes in the annular diaphragm so that they benefit the compression driver's acoustic output. Embodiments of compression chamber and diaphragms with geometry that facilitate modal control are provided.

Abstract: A coaxial compression driver including a housing, a first vibrating membrane for lower frequencies housed in the housing and facing a first compression chamber in communication with a first acoustic conduit, a second vibrating membrane for higher frequencies housed in the housing and facing a second compression chamber in communication with a second acoustic conduit, and a passive acoustic low pass filter housed in the first acoustic conduit, where the first and second vibrating membranes are arranged in the housing coaxial with respect to each other, where the first and second acoustic conduits converge into a common output acoustic conduit, and where the passive low pass filter is a lumped parameters filter which prevents frequencies above a predetermined cutoff frequency from passing from the second to the first acoustic conduit and allows frequencies below the predetermined cutoff frequency to pass from the first to the common output acoustic conduit.

Abstract: A coaxial compression driver including a housing, a first vibrating membrane for lower frequencies housed in the housing and facing a first compression chamber in communication with a first acoustic conduit, a second vibrating membrane for higher frequencies housed in the housing and facing a second compression chamber in communication with a second acoustic conduit, and a passive acoustic low pass filter housed in the first acoustic conduit, where the first and second vibrating membranes are arranged in the housing coaxial with respect to each other, where the first and second acoustic conduits converge into a common output acoustic conduit, and where the passive low pass filter is a lumped parameters filter which prevents frequencies above a predetermined cutoff frequency from passing from the second to the first acoustic conduit and allows frequencies below the predetermined cutoff frequency to pass from the first to the common output acoustic conduit.

Abstract: A coaxial compression driver including a housing, a first vibrating membrane for relatively lower frequencies housed in the housing where the first vibrating membrane faces a first compression chamber in communication with a first acoustic conduit, a second vibrating membrane for relatively higher frequencies housed in the housing, where the second vibrating membrane faces a second compression chamber in communication with a second acoustic conduit the first vibrating membrane and the second vibrating membrane arranged in the housing being coaxial or substantially coaxial with respect to each other, the first acoustic conduit and the second acoustic conduit converge into a common output acoustic conduit, and the coaxial compression driver includes a passive low pass filter at least partially housed in the first acoustic conduit.

Abstract: A compression driver including an acoustic outlet duct, a magnetic assembly having a permanent magnet and an air gap, a vibrating membrane with a movable coil adapted and configured to move inside the air gap, where the vibrating membrane includes a first face facing a first chamber communicating with the outlet duct, where the first chamber is a compression chamber, a second face opposite to the first face and facing a second chamber communicating with the air gap and opposite to the first chamber, where the compression driver includes at least one acoustic connection duct which puts in communication the second chamber with the acoustic outlet duct.

Abstract: A compression driver including an acoustic outlet duct, a magnetic assembly having a permanent magnet and an air gap, a vibrating membrane with a movable coil adapted and configured to move inside the air gap, where the vibrating membrane includes a first face facing a first chamber communicating with the outlet duct, where the first chamber is a compression chamber, a second face opposite to the first face and facing a second chamber communicating with the air gap and opposite to the first chamber, where the compression driver includes at least one acoustic connection duct which puts in communication the second chamber with the acoustic outlet duct.

Abstract: A coaxial compression driver including a housing, a first vibrating membrane for relatively lower frequencies housed in the housing where the first vibrating membrane faces a first compression chamber in communication with a first acoustic conduit, a second vibrating membrane for relatively higher frequencies housed in the housing, wherein the second vibrating membrane faces a second compression chamber in communication with a second acoustic conduit the first vibrating membrane and the second vibrating membrane arranged in the housing being coaxial or substantially coaxial with respect to each other, the first acoustic conduit and the second acoustic conduit converge into a common output acoustic conduit, and the coaxial compression driver includes a passive low pass filter at least partially housed in the first acoustic conduit.