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Biomedical subjects

J Foort

Publications and source records attributed to J Foort.

13 recordsLinked to original sources
PubMed1992

A computer-aided socket design procedure for above-knee prostheses.

A computer-aided socket design procedure (CASD) has been developed whereby an above-knee socket shape can be created based on anthropometric measurements taken from an amputee. The anthroometric measurements are used to select a subset of three reference shapes from a Reference Shape Library stored in the computer in the form of three-dimensional numerical data. Transformation procedures then scale the reference shapes at each cross-sectional level to match the amputee's cross-sectional areas. Blending of the three shapes is determined by tissue mass weighting factors, to yield a single custom socket configuration, known as the "basic socket shape." Subsequent graphical procedures in the CASD system allows further sculpting of the shape in the form of interactive adjustments of the numerical data to reach the socket shape desired by the prosthetist. The resultant shape data can then be transferred to a computer numerically controlled (CNC) milling machine to carve a model of the socket shape.

Artificial Limbs↗
PubMed1991

Computer-aided design and manufacture of an above-knee amputee socket.

This paper describes the initial test results obtained from a newly developed computer-aided socket design (CASD) and manufacturing (CASM) process for above-knee amputees. Anthropometric measures taken from an amputee provided input information to a CASD system. Using these measurements, data from a reference shape library stored in the computer were selected and modified to create a unique socket shape reflecting the particular characteristics of the amputation stump. The resultant shape was produced as a 'primitive' test socket by a CASM process. Numerical shape data were then transferred to a CNC milling machine to construct a negative cast, from which the primitive socket was produced by a vacuum-forming procedure. The resultant primitive socket shape was fitted and the amputee was able to load the socket without discomfort. Some shape discrepancies were identified and the shape data were modified interactively by the CASD system to create a final socket shape. The final socket shape was manufactured and worn by the amputee during a 35 min walking trial. Subjective evaluation was that the socket provided comfort and control comparable with that of the conventional socket, and proved to be acceptable to the amputee. This was followed by a 2-month home trial which was also successful. The CASD socket shapes were compared numerically in area, shape and volume with data taken from the original socket worn by the amputee, a new socket made by conventional methods and a topographic model of the amputation stump. The final CASD socket shape compared favourably with that of a socket manufactured by conventional methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry↗
PubMed1989

A reference shape library for computer aided socket design in above-knee prostheses.

A Reference Library of socket shapes for an Above-Knee Computer Aided Socket Design (CASD) System has been created. This library forms part of a more general CASD System (Dean & Saunders, 1985; Novicov & Foort, 1982). It consists of a matrix of reference shapes representing above-knee socket characteristics and is based upon skeletal structure, residuum length and tissue mass. A set of 27 biomechanical reference shapes in the form of male plaster casts were produced by a combination of CNC milling and traditional artisan techniques. Each reference shape was digitized to obtain its cylindrical coordinates. Cross-sectional areas and tissue distributions within each shape and between the shapes were analyzed, modified and then stored numerically within the computer for further implementation of the CASD System for the above-knee amputees. The creation and the analysis of the reference shape data is described.

Artificial Limbs↗
PubMed1985

Computer aided design of prosthetic sockets for below-knee amputees.

A computer-aided sculpting system for use in prosthetics is described. The prosthetist's sculpting tools now consist of a computer, a graphics terminal, a mouse and an on-screen moveable cursor. Accompanied by the system software, these tools allow systematic modification of a primitive socket using techniques analogous to those used by a prosthetist working with rasps and plaster.

Amputation Stumps↗
PubMed1985

Experimental fittings of sockets for below-knee amputees using computer aided design and manufacturing techniques.

The experiments showed that it is possible to successfully design a socket using a computer based socket model. Variability of results, however indicates the existence of shortcomings. These were identified as inadequacies in the caliper method used to measure the stumps; inability to make the sockets total contact; lack of flexibility of the design process in the Round #1 computer CASD system. It was shown by results of the MERU fittings that an iterative procedure in the hands of an inexperienced person would lead to a degree of success comparable to that achieved by experienced persons using judgement. Also indicated was that experienced prosthetists were able to transfer their skills to the CASD system. This is indicated by the fact that they achieved 5 Class IV results with 8 sockets as compared to 2 Class IV results with 10 sockets achieved by the inexperienced operator.

Amputation Stumps↗
PubMed1978

Rehabilitation engineering as the crow flies. Part IV--Criteria and constraints.

When engineers function in a biomechanics clinic team, collecting information for the definition and solution of problems, and developing solutions in a logical pattern, then establishment of criteria by which to judge actions and results at various stages are essential. In our procedures, we make the most general statement we can which will indicate the goal we have for the patient or the type of patient being considered. Based on this, we proceed with a breakdown of the goal into increasingly explicit statements keeping the objective in focus. Eventually, with the criteria we need in order to decide "yes or no" to any aspect of the solution developing, we consider the constraints. These we see as imposed by the life-requirements of the patient, the effects of the physical environment, the limitations imposed by the social environment, and the limits of available technology including the skills of the designers, the manufacturing capabilities and the distribution system with which the designers must cope. When a "checklist" of requirements and limits has been established, the "critical eye" watches over the rehabilitation engineer as he in effect watches over himself!

Activities of Daily Living↗