Patent Application
20080247579
One of the fundamental criteria in the design of hearing aids is to minimize size. As the current trend in the hearing aid industry continues to make shells smaller, the size requirement implies that every tenth of a millimeter of the shell height plays an important role in the determination of its the overall size. This makes the need for accurate representation of virtual models of components in the shell during modeling very important.
The present invention provides system and method for a precise representation and handling of electronic components inside the hearing aid shell in which the physical structure of the components can be accounted for. Components inside the shell, particularily a receiver, a hybrid, etc., typically comprise the “hard part” (the component itself), and the “soft part” (e.g., some form of resin boot around the component to avoid direct contact of component with the shell) The focus thus is on the correct handling of components that consist of hard and soft parts in computerized software systems.
The following definitions and abbreviations are used herein.
The present invention provides the software implementation of representative electronic component behavior in a hearing aid instrument. This requires the modeling of flexible material behavior, representative deformation modeling, and dynamic constraints modeling. Within the context of this implementation, electronic components are modeled as comprising a hard core and a soft exterior. While the internal core remains intact during virtual and physical component placement, the exterior cover undergoes flexural motion when exposed to contact forces. In the prior art automation software systems available for hearing instrument design, these concepts are completely absent, although the general basis for correct replication of physical assemblying protocols in hearing instrument manufacturing and for process automation is known.
The goal of the present invention is to mimic the behaviour of the components having soft parts in computerized 3D models to have the models behave as identical as possible to that of the real world.
The handling of components with a flexible cover does not require any special user interactions, and can be seamlessly integrated into other systems that automate the hearing aid design and manufacturing. Therefore, during the positioning of the components in the system software, the physical structure of the components in real world will be accounted for in 3D model's behaviour.
Accordingly, a method is provided for designing hearing aids having flexible parts, comprising entering three dimensional data related to both a soft part and a hard part of a hearing aid component into a computer-based system; entering information related to material characteristics for both the soft part and the hard part of the component; placing and moving the component within a hearing aid shell in a model generated by the system; calculating forces, stresses, and degree of deformation for parts of the component based on the location of the component and at least one of another component and the shell; and revising the three dimensional data model based upon the calculated degree of deformation.
Similarly, an appertaining system is provided for designing hearing aids having flexible parts, comprising an input mechanism for entering three dimensional data related to both a soft part and a hard part of a hearing aid component; a first storage area for storing the three-dimensional data; a second storage area for storing information related to material characteristics for both the soft part and the hard part of the component; a software routine for placing and moving the component within a hearing aid shell in a model generated by the system; a software routine for calculating forces, stresses, and degree of deformation for parts of the component based on the location of the component and at least one of another component and the shell; and a software routine for revising the three dimensional data model based upon the calculated degree of deformation.
The invention is described with respect to various preferred embodiments as illustrated in the drawing figures and appertaining descriptive text below.
Components with flexible covers are movable on the display and within the system model space in the same way as components without flexible covers are movable. Each component with a flexible cover 10 comprises a hard part and a soft part, where the hard part is the component itself 20 and the soft part 30 is the flexible cover. Both the hard part and the soft part can be represented by corresponding STL files.
If the component with flexible cover 10 touches a shell of the hearing aid, then the component shape is adapted to match the behaviour of the flexible cover in the real world. Collision notification is not triggered for the soft part as it would be for the hard part if the hard part were to intersect with the shell or other hard part components; the soft part is not permitted to penetrate into the shell.
In the case where the soft part of the component is about to penetrate the shell, the necessary deformation calculations are applied on the soft part of the component to calculate a new deformed shape of the soft part. In case several soft parts of several different components are about to penetrate each other, necessary deformation calculations are applied on the soft part of all involved components.
This is achieved by the software ensuring that forces applied to each component create a zero sum together. If any of the components have a sum of all forces applied to it that differs from zero, then the software automatically repositions the component in the nearest position at which a zero sum can be achieved. This is accomplished by moving the component in the software, in a direction of the non-zero-value vector until the sum of the forces is zero.
On every place where a flexible cover is about to penetrate the shell, the forces pushing e.g., a receiver from the surfaces are applied to the flexible cover to calculate the necessary modifications.
This plate 40 simulates a hearing aid shell wall (discussed below). In a real life application, there is no plate provided by the software, and the component with flexible cover 10 interacts with the 3D objects present in the design space (e.g. the shell, other components). The hard part of the component is not permitted to be deformed, but the soft part of the component is allowed to be deformed according to a known finite element analysis approach. With this approach, the soft part of the component is represented by a geometrically similar model consisting of multiple, linked, simplified representations of discrete regions—i.e., finite elements on an unstructured grid. Equations of equilibrium, in conjunction with applicable physical considerations such as compatibility and constitutive relations, are applied to each element, and a system of simultaneous equations is constructed. The system of equations is solved for unknown values using the techniques of linear algebra or nonlinear numerical schemes. Although this is an approximate method, the accuracy of this approach can be improved by refining the mesh in the model using more elements and nodes.
The software provides the possibility to specify the materials from which hard and soft parts of each component are created. As a part of material specification, Young's modulus may be utilized. For example, Young's modulus for Viton is 0.8 MPa, and Young's modulus for steel 2*105 MPa.
The know techniques utilized may be found in the following references, which are herein incorporated by reference: Kreyszig, E., Advanced Engineering Mathematics, John Wiley and Sonds, Inc., New York (1962); Lekhnitskii, S. G., Theory of Elasticity of an Anisotropic Elastic Body, Holden-Day, San Fransisco (1963); Oden, J. T., Mechanics of Elastic Structures, McGraw-Hill, New York (1968); and Przemieniecki, J. S., Theory of Matrix Structural Analysis, McGraw-Hill, New York (1968). Furthermore, analysis tools, such as the ANSYS software produced by ANSYS, Inc., or software modultes having similar functionality may be utilized.
When the user moves the component 10 back from the shell wall 40, the deformation of flexible cover parts 30 is gradually removed to reflect the change in the forces applied to the component with flexible cover 10.
The
When the pressure is applied, the flexible cover 30 is deformed in the software as shown in
For the purposes of promoting an understanding of the principles of the invention, reference has been made to the preferred embodiments illustrated in the drawings, and specific language has been used to describe these embodiments. However, no limitation of the scope of the invention is intended by this specific language, and the invention should be construed to encompass all embodiments that would normally occur to one of ordinary skill in the art.
The present invention may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of hardware and/or software components configured to perform the specified functions. For example, the present invention may employ various integrated circuit components, e.g., memory elements, processing elements, logic elements, look-up tables, and the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. Similarly, where the elements of the present invention are implemented using software programming or software elements the invention may be implemented with any programming or scripting language such as C, C++, Java, assembler, or the like, with the various algorithms being implemented with any combination of data structures, objects, processes, routines or other programming elements. The invention can be implemented in a computer running any Microsoft Windows operating system, such as Windows 2000, Windows XP, Windows Vista, or the like, or any Macintosh, Unix-based, or any other operating system on a computer system ranging from a personal laptop or palmtop to mainframe servers, where applicable. Furthermore, the present invention could employ any number of conventional techniques for electronics configuration, signal processing and/or control, data processing and the like. The word mechanism is used broadly and is not limited to mechanical or physical embodiments, but can include software routines in conjunction with processors, etc.
The particular implementations shown and described herein are illustrative examples of the invention and are not intended to otherwise limit the scope of the invention in any way. For the sake of brevity, conventional electronics, control systems, software development and other functional aspects of the systems (and components of the individual operating components of the systems) may not be described in detail. Furthermore, the connecting lines, or connectors shown in the various figures presented are intended to represent exemplary functional relationships and/or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections may be present in a practical device. Moreover, no item or component is essential to the practice of the invention unless the element is specifically described as “essential” or “critical”. Numerous modifications and adaptations will be readily apparent to those skilled in this art without departing from the spirit and scope of the present invention.
