NDLI: Design and Tesing of a Halo Orthosis to Reduce Pin Loosening Using Constraint Analysis

Content Provider	The American Society of Mechanical Engineers (ASME) Digital Collection
Author	Richard, E. Stamper Kuester, W. Matthew Matthew, P. Meek
Abstract	A halo orthosis is a medical device used for restricting motion of the skull and cervical spine during accident and surgery recovery situations where minimal movement of the skull and spine is required for proper healing. Pin loosening is one of the most common complications with a commonly cited incident rate of 36%. The root cause of the loosening is related to changes in the skull geometry at the pin site and the inability of current halo systems to adapt to those changes. We hypothesize that the inability of current halo systems to adapt to these small pin site geometry changes is driven by the over constrained nature of the skull relative to the halo ring when viewed as a mechanism in the context of the Grubler / Kutzbach criteria. Accordingly, an exactly constrained 3-pin halo ring design is proposed. A prototype of the exactly constrained halo ring that is instrumented to measure pin forces was fabricated along with a skull model that simulates radial recession of the bone at the pin sites. The testing suggests that the pin forces in the exactly constrained 3-pin halo are less sensitive to the radial recession of the pin sites than the current over constrained 4-pin halo configurations. The average pin force in the over constrained 4-pin design decreased by 63% after 0.52 mm of simulated radial recession at two of the pin sites. The average pin force in the exactly constrained 3-pin design decreased by 1% after 0.52 mm of simulated radial recession at two of the pin sites.
Sponsorship	Design Engineering Division and Computers and Information in Engineering Division
Starting Page	725
Ending Page	730
Page Count	6
File Format	PDF
ISBN	0791836253
DOI	10.1115/DETC2002/MECH-34282
e-ISBN	0791836037
Volume Number	Volume 5: 27th Biennial Mechanisms and Robotics Conference
Conference Proceedings	ASME 2002 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference
Language	English
Publisher Date	2002-09-29
Publisher Place	Montreal, Quebec, Canada
Access Restriction	Subscribed
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in