Method of producing profiled sheets as prosthesis

• US 20030109784A1
• Filed: 11/01/2002
• Published: 06/12/2003
• Est. Priority Date: 05/10/2000
• Status: Abandoned Application

• Current Assignee: Nanyang Polytechnic
• Original Assignee: Nanyang Polytechnic
• Inventors: Loh, Kwok Weng Leonard, Ong, Teddy Eng Hoo
• Application Number:
  US10/275,144
• Publication Number:
  US 20030109784A1
• Time in Patent Office: Days
• US Class Current: 600/427
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61F 2/0063 Implantable repair or support meshes, e.g. hernia meshes
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/2846 Support means for bone substitute or for bone graft implants, e.g. membranes or plates for covering bone defects nets or sleeves applied to surface of endoprostheses A61F2/30907; bone plates A61B17/80; bone regeneration in dental surgery A61C8/0006
• CPC Class Codes: A61F 2/2875 Skull or cranium A61F2/2803 and A61F2/3099 take precedence
• CPC Class Codes: A61F 2/30942 for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques
• CPC Class Codes: A61F 2002/30948 using computerized tomography, i.e. CT scans
• CPC Class Codes: A61F 2002/30952 using CAD-CAM techniques or NC-techniques
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30962 using stereolithography
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/85 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B22F 3/24 After-treatment of workpieces or articles B22F3/1146 takes precedence
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 19/4207 in which a model is traced or scanned and corresponding data recorded
• CPC Class Codes: G05B 2219/35044 Tool, design of tool, mold, die tooling
• CPC Class Codes: G05B 2219/45168 Bone prosthesis
• CPC Class Codes: G05B 2219/45204 : Die, mould making
• CPC Class Codes: G05B 2219/4717 : Machine 3-D model by tracing two 2-D models
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

A method of profiling a substrate as prosthesis for a structural defect in a patient whereby pressworking technique is used to press a prosthesis between a punch and a cavity mould to form the prescribed shape. The punch and cavity of the mould contains a profile that is computer generated and designed to closely match the patient'"'"'s profile and to give the most natural and fitting prosthesis. The present method uses a set of 2-dimensional (2D) CT scans of the region around the defect and converts them into a 3 dimensional (3D) digital model, after which a prototype of the defective region is optionally produced by rapid prototyping techniques. The 3D digital model of the prosthesis is then used to digitally construct a set of profiling tools after which the actual punch and mould are physically produced.

Claims

1. A method of profiling a substrate as a prosthesis for a structural defect in a patient comprising:

a) generating CT scan data of a defective region of said patient in the region around said structural defect;

b) converting said CT scan data of said defective region into a 3-dimensional digital model of said defective region;

c) fabricating a defective region prototype using said 3-dimensional digital model of said defective region;

d) creating a 3-dimensional digital replacement of said structural defect, steps comprising;

(i) obtaining a non-defective 3-dimensional digital model of at least one non-defective subject;

(ii) comparing said non-defective 3-dimensional digital model with said 3-dimensional digital model of said defective region;

(iii) selecting said non-defective 3-dimensional digital model having a non-defective area that matches a defective area in said 3-dimensional digital model of defective region; and

(iv) subtracting said non-defective 3-dimensional model from said 3-dimensional digital model of said defective region to produce said 3-dimensional digital replacement;

e) fabricating a set of profiling tools; and

f) pressing said substrate with said profiling tools to form said prosthesis.

2. A method according to claim 1 further comprising the step of fabricating a replacement prototype from said 3-dimensional digital replacement;

and

combining said replacement prototype and said defective region prototype to form a reconstruction prototype before step (e).

3. A method according to claim 2 wherein said step (e) further comprises the steps of:

(i) scanning said reconstruction prototype to create a 2-dimensional digital surface;

(iii) selecting a region of said 2-dimensional digital surface corresponding to said defective region to generate a digital profile; and

(iv) fabricating a set of profiling tools using said digital profile.

4. A method according to claim 3 wherein said step (iv) further comprises the steps of:

producing a digital punch and a digital mould using said digital profile; and

fabricating a set of profiling tools from said digital punch and said digital mould.

5. A method according to claim 3 wherein said step (iv) further comprises the steps of:

generating a tool path for a high speed milling machine; and

milling a mould cavity and a punch surface using said high speed milling machine.

6. A method according to claim 1 wherein step (e) further comprises:

(i) creating a digital block

(ii) offsetting and subtracting a prescribed region of said digital replacement from said digital block to create a digital cavity mould;

(iii) filling the hollow area within said digital replacement to form a digital punch; and

(iv) fabricating a mould and a punch from said digital mould and digital punch respectively.

7. A method according to claim 6 wherein a 2-dimensional surface of said digital replacement is first created before step (ii);

and steps (ii) and (iii) are performed using said 2-dimensional surface instead of said digital replacement.

8. A method according to claim 1 wherein said structural defect comprising of said defective area is located on a defective side opposite to a non-defective side of a substantially symmetrical bone structure;

and step (d) further comprises;

(i) creating a mirror image of said non-defective side of said bone structure;

(ii) positioning said mirror image directly on said defective area; and

(iii) subtracting said mirror image from said defective side to produce said digital replacement.