US 7747305

US7747305B2 — Patent Overview

Title: Computer-aided-design of skeletal implants
Patent number: US7747305B2
Application number: US11/299,138
Inventors: David Dean, Kyoung-June Min, Robert A. Ratcheson
Original assignee: Case Western Reserve University
Current assignee (as listed): Osteoplastics LLC
Priority date: 2003-06-11
Filing date: 2005-12-09
Publication date: 2010-06-29
Status: Expired – Fee Related; adjusted expiration 2025-08-26
Source: https://patents.google.com/patent/[US7747305](/patent/US7747305)/en

Purpose

The patent relates to generating patient-specific, pre-operatively fabricated prosthetic implants, and more particularly to a cranial implant. It addresses a practical problem: cranial defects require well-fitting implants to protect the brain from trauma or infection and to restore aesthetic shape to the head. Where sufficient cranial bone is unavailable for engraftment, malleable biocompatible materials are used instead. The text notes that manual skill required, surgical risk, patient cost, and surgery length all increase with defect size, and that designing and producing a large, well-fitting implant is not trivial even with high-resolution 3D CT as a design basis.

Plain-language scope

The supplied excerpt describes computer-aided design of skeletal implants using geometric modeling concepts. It discusses constructive solid geometry (CSG) and boundary representation (B-rep) as modeling approaches; parametric surfaces including Bezier, B-splines, and NURBS; and the difficulty of directly manipulating 3D parametric surfaces via control points to create complex freeform designs. It also mentions B-spline surface control point schemes derived from previously collected polygonal B-rep models, computationally expensive conversion calculations, and flexible B-spline creation via hierarchical patch refinement and automated conversion. The classifications cover customized prosthesis design using CT/NMR scans and CAD-CAM techniques, cranial/skull prostheses, additive manufacturing, and bone prostheses.

What the excerpt does not establish

The supplied text contains no claim language, no detailed description of method steps or apparatus, no named prior-art references with dates, and no figures or reference numerals. It therefore does not establish the actual claimed scope, the specific clinical workflow, or the full written description. The excerpt also does not address litigation, ownership transfers, validity, or prior art.