Abstract: A method for specifying design rules for a manufacturing process includes providing a training set of 3D point meshes that represent an anatomical structure, for each 3D point mesh, finding groupings of points that define clusters for each shape class of the anatomical structure, calculating a prototype for each shape class cluster, and associating one or more manufacturing design rules with each shape class prototype. The method includes providing a new 3D point mesh that represents an anatomical structure, calculating a correspondence function that maps the new 3D point mesh to a candidate shape class prototype by minimizing a cost function, calculating a transformation that aligns points in the new 3D point mesh with points in the candidate shape class prototype, and using the rules associated with the shape class prototype, if the candidate shape class prototype is successfully aligned with the new 3D point mesh.

Abstract: A method for detecting anatomical features in 3D ear impressions includes receiving a 3D digital image of a 3D ear impression, obtaining a surface of the ear impression from the 3D image, analyzing the surface with one or more feature detectors, the detectors adapted to detecting generic features, including peak features, concavity features, elbow features, ridge features, and bump features, and derived features that depend on generic features or other derived features, and forming a canonical ear signature from results of the detectors, where the canonical ear signature characterizes the 3D ear impression.

Abstract: A method of designing hearing aid molds is disclosed whereby two shapes corresponding to graphical images of ear impressions are registered with each other to facilitate joint processing of the hearing aid design. In a first embodiment, a first graphical representation of a first ear impression is received and a feature, such as the aperture of the ear impression, is identified on that graphical model. A first vector is generated that represents the orientation and shape of that first feature. The three-dimensional translation and rotation of that first vector are determined that are necessary to align the first vector with a second vector representing the orientation and a shape of a feature, once again such as the aperture, of a second ear impression. In another embodiment, this alignment is then refined by minimizing the sum of the distances between points on the first and second graphical representations.

Abstract: A method for rigid registration of ear impression models, including: extracting a canal region from an undetailed ear impression model, the undetailed ear impression model representing an undetailed surface of an ear canal and outer ear geometry; extracting a canal region from a detailed ear impression model, the detailed ear impression model representing a detailed surface of the ear canal; generating an orientation histogram for the canal region of the undetailed ear impression model and an orientation histogram for the canal region of the detailed ear impression model; performing a rotational alignment between the orientation histograms; computing a translational shift between the canal regions after performing the rotational alignment; and performing a registration between the undetailed and detailed ear impression models after computing the translational shift.

Abstract: A method of designing hearing aid molds is disclosed whereby skeletons, or simplified models, of two ear impressions are used to register the graphical representations of the molds to facilitate the joint design of hearing aid shells. The center points of at least a portion of contour lines on the surface of each ear impression are identified. Then, for each ear impression, by connecting these center points to each adjacent center point, a skeleton that represents a simplified model of an ear impression is generated. Vectors describing the distance and direction from the points of each skeleton to an anatomical feature of each ear impression are identified to obtain a correspondence between the points of each skeleton. Three-dimensional translations and rotations of a feature vector of at least one of the skeletons are determined to achieve alignment of the skeleton of one ear impression with the skeleton of another impression.

Abstract: A method identifying apertures of ear impressions is disclosed. A plurality of contour lines associated with an ear impression are determined and a difference value between a value of a characteristic, such as the diameter, of each contour line and that characteristic of an adjacent contour line is determined. The aperture is identified as being that contour line having the greatest difference value. The contour lines are determined by identifying where a plane intersects the surface of the graphical representations. In another embodiment, the contour lines are assigned a weight. A contour index is then calculated for each contour line as a function of the difference value and these weights. According to this embodiment, the aperture is identified as being a contour line that is adjacent to that contour line having the greatest contour index.

Abstract: A method for specifying design rules for a manufacturing process includes providing a training set of 3D point meshes that represent an anatomical structure, for each 3D point mesh, finding groupings of points that define clusters for each shape class of the anatomical structure, calculating a prototype for each shape class cluster, and associating one or more manufacturing design rules with each shape class prototype. The method includes providing a new 3D point mesh that represents an anatomical structure, calculating a correspondence function that maps the new 3D point mesh to a candidate shape class prototype by minimizing a cost function, calculating a transformation that aligns points in the new 3D point mesh with points in the candidate shape class prototype, and using the rules associated with the shape class prototype, if the candidate shape class prototype is successfully aligned with the new 3D point mesh.

Abstract: A method for detecting anatomical features in 3D ear impressions includes receiving a 3D digital image of a 3D ear impression, obtaining a surface of the ear impression from the 3D image, analyzing the surface with one or more feature detectors, the detectors adapted to detecting generic features, including peak features, concavity features, elbow features, ridge features, and bump features, and derived features that depend on generic features or other derived features, and forming a canonical ear signature from results of the detectors, where the canonical ear signature characterizes the 3D ear impression.

Abstract: A method for determining a degree of similarity between ear canal models includes receiving a first mesh model representing an inner surface of a first ear. A set of points is sampled within the first mesh model. Each of the sampled set of points is matched to a corresponding point of a second mesh model representing an inner surface of a second ear. A shape distance between the first mesh model and the second mesh model is calculated based on the matched sets of points. A determination of the degree of similarity between the inner surface of the first ear and the inner surface of the second ear is provided based on the calculated shape distance.

Abstract: A method and system for detecting the concha and intertragal notch in an undetailed 3D ear impression is disclosed. The concha is detected by searching vertical scan lines in a region surrounding the aperture using a two-pass method. The intertragal notch is detected based on a bottom contour of the 3D undetailed ear impression and a local coordinate system defined for the 3D undetailed ear impression.

Abstract: A method for rigid registration of ear impression models, including: extracting a canal region from an undetailed ear impression model, the undetailed ear impression model representing an undetailed surface of an ear canal and outer ear geometry; extracting a canal region from a detailed ear impression model, the detailed ear impression model representing a detailed surface of the ear canal; generating an orientation histogram for the canal region of the undetailed ear impression model and an orientation histogram for the canal region of the detailed ear impression model; performing a rotational alignment between the orientation histograms; computing a translational shift between the canal regions after performing the rotational alignment; and performing a registration between the undetailed and detailed ear impression models after computing the translational shift.

Abstract: A method identifying apertures of ear impressions is disclosed. A plurality of contour lines associated with an ear impression are determined and a difference value between a value of a characteristic, such as the diameter, of each contour line and that characteristic of an adjacent contour line is determined. The aperture is identified as being that contour line having the greatest difference value. The contour lines are determined by identifying where a plane intersects the surface of the graphical representations. In another embodiment, the contour lines are assigned a weight. A contour index is then calculated for each contour line as a function of the difference value and these weights. According to this embodiment, the aperture is identified as being a contour line that is adjacent to that contour line having the greatest contour index.

Abstract: A method of designing hearing aid molds is disclosed whereby skeletons, o r simplified models, of two ear impressions are used to register the graphical representations of the molds to facilitate the joint design of hearing aid shells. The center points of at least a portion of contour lines on the surface of each ear impression are identified. Then, for each ear impression, by connecting these center points to each adjacent center point, a skeleton that represents a simplified model of an ear impression is generated. Vectors describing the distance and direction from the points of each skeleton to an anatomical feature of each ear impression are identified to obtain a correspondence between the points of each skeleton. Three-dimensional translations and rotations of a feature vector of at least one of the skeletons are determined to achieve alignment of the skeleton of one ear impression with the skeleton of another impression.

Abstract: A method of designing hearing aid molds is disclosed whereby two shapes corresponding to graphical images of ear impressions are registered with each other to facilitate joint processing of the hearing aid design. In a first embodiment, a first graphical representation of a first ear impression is received and a feature, such as the aperture of the ear impression, is identified on that graphical model. A first vector is generated that represents the orientation and shape of that first feature. The three-dimensional translation and rotation of that first vector are determined that are necessary to align the first vector with a second vector representing the orientation and a shape of a feature, once again such as the aperture, of a second ear impression. In another embodiment, this alignment is then refined by minimizing the sum of the distances between points on the first and second graphical representations.