Computer integrated design and manufacturing of patient specific lower limb orthoses through 3D reconstruction / Morshed Alam
Patients with stroke and other neurological disorders like trauma, multiple sclerosis (MS) experience different lower limb disabilities due to various damages in neuromuscular system. Orthotic devices are prescribed to compensate muscle weakness, prevent unwanted movement of the impaired limb. De...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Published: |
2014
|
| Subjects: | |
| Online Access: | http://studentsrepo.um.edu.my/8296/1/COMPUTER_INTEGRATED_DESIGN_AND_MANUFACTURING_OF_PATIENT_SPECIFIC_LOWER_LIMB_ORTHOSES_THROUGH_3D_RECONSTRUCTION.pdf http://studentsrepo.um.edu.my/8296/ |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Patients with stroke and other neurological disorders like trauma, multiple sclerosis (MS)
experience different lower limb disabilities due to various damages in neuromuscular system.
Orthotic devices are prescribed to compensate muscle weakness, prevent unwanted
movement of the impaired limb. Design and manufacturing methods of lower limb orthoses
involve manual techniques e.g. casting and moulding of the limbs to be treated, vacuum
forming etc. Such methods are time consuming, require skilful labour and often based on
trial and error rather than systematic engineering and evidence based principles.
In recent years, 3D scanning and reconstruction of medical images facilitate making 3D
computer models of lower limb, which allows computer aided design (CAD) tools to be
incorporated in orthotic design. All these approaches rely on the external model of lower
limb and limited to single piece plastic ankle foot orthosis (AFO) only. To design orthosis
with articulated joint, precise alignment of anatomical joint and mechanical axis is necessary.
However, it is difficult to infer joint axes from external models as it is partially specified by
skeletal structure. In our research, a design approach for custom knee ankle foot orthosis and
ankle foot orthosis with commercially available joints has been demonstrated, which involves
skeletal structure of lower limb for locating anatomical axes to ensure accurate alignment of
orthotic mechanical joint. CAD models of the orthotic components were developed based on
the 3D models of a healthy subject’s lower limb, which were developed through 3D
reconstruction. Components of the orthotics were fabricated by rapid prototyping and
machining to demonstrate the new approach. The fabricated orthoses were evaluated by a
certified orthotist and the performance of the custom made AFO was compared statistically
with a pre-fabricated AFO with similar ankle joint.
The manufacturing process requires approximately 50% lesser time to develop AFO and 70%
lesser time to develop KAFO compared to Brace and Limb laboratory of University Malaya.
Unlike traditional approaches, the design technique facilitates exact positioning of articulated
joint. The developed orthoses are light in weight, comfortable and easy to don and doff.
Biomechanical test implies that the fabricated AFO provides better range of motion than a
pre-fabricated AFO with same ankle joint. Although the custom AFO allowed significantly
higher plantar flexion during pre-swing compared to pre-fabricated AFO condition (MD =
1.734, MSD = 1.55), the subject’s ankle required to generate significantly higher power with
the pre-fabricated AFO (MD = 0.141, MSD = 0.035). These findings suggest that the subject
had to overcome higher resistance with pre-fabricated AFO compared to custom made AFO.
Simultaneous viewing of exterior and skeletal geometry might help the clinicians modify the
design to enhance performance of the orthotic device. |
|---|