1. Non-Invasive Head-Holder for Neurosurgical Procedures
Sponsor:
Dr. Jacob Joseph
University of Michigan Hospital
Department of Neurosurgery
Section Instructor:
Professor Jeffrey Stein
University of Michigan
Mechanical Engineering
ME 450 Team #18
Jessica Deese, Anne Gu, Syeda Maisa, Jane Modes
Problem
The Mayfield Skull Clamp has been the standard device for affixing a patient’s head in place during neurosurgery for the past 70 years [1]. Although the Mayfield can hold the head rigidly, it does so by driving three pins into the skull. Because of this invasive method of fixation, many problems arise such as skull fractures, lacerations of the scalp, and air embolisms [2].
Final Design
Validation
Quick and Simple Setup
Accommodations for Emergency Procedures
Range of Applicable force
Providing Stability
2 hour test with cadaver head
7 hour test with model head
Note
Additional testing must be performed to increase sample size
VALIDATION
User requirements satisfied by design are breathing tube access, avoid pressure on eyes, and access for neural monitoring.
User requirements satisfied by key features are non-invasive fixation, patient adjustability, and accommodate emergency procedures.
Validation details (testing protocol, results) and design critique/future work. Photos and graphs/analysis from your testing belong on this panel
Conclusion
Setup time is < 2 min
Preliminary trend indicates faster setup timing with practice
Conclusion
Setup time is << 3 mins and thus the rest of the time could be allotted to turning of the patient for CPR
Key Features
Pressure Applicator
Headband
Headband
Mayfield Device
Non-invasive fixation
Patient adjustability
Project Scope
To address these problems, we are designing a non-invasive head- holder device for spinal surgeries where patients are in the prone position. Our device is trying to bridge the gap between devices that are non-invasive but apply pressure on the eyes (DORO) and devices that avoid pressure on the eyes but are invasive (Mayfield).
Conclusion
Minimum force .45*6=2.75 (lb. force)
Maximum force 15*6=90 (lb. force)
One turn = (.45 lb. force)
Headband Frame with 6 Threaded Holes
Quick Release Mechanism
Quick Release Mechanism
Attachment to Table Mount
Attachment to Table Mount
Accommodates emergency procedures
Uses existing solution to keep cost low
Prone Position
DORO Headrest
Design Critique / Future Plans
Change shape of the screw cap to allow for easier turning
Develop system to turn all PA’s at once
Add sensors for detecting pressure to optimize surgical process
Convert 3D printed mate to metal mate for durability
Disposable PA padding
User Requirements Specifications
FUTURE WORK
Talk about design critique
Provide Stability
Supports a mass of kg [3]
Patient movement in any direction produced by surgical load ≤ 12.7 mm [3]
Non-Invasive
Class I non-invasive level [4]
Accommodate emergency procedures
Detach device from bed fixture and turn patient in ≤ 3 minutes [5]
Quick and Simple Setup
Average setup time ≤ 5 minutes
Patient Adjustability
Longitudinal head length from cm [6]
Lateral head length from 13.3 – 16.5 cm [6]
Breathing Tube Access
Area between bottom of nose to bottom of the chin (~18.7 cm) and ear to ear (~16.5 cm) [6]
Avoid Pressure on Eyes
Maxillary Zone: Area between top of the eye to upper lip (~ 7.7 cm) and ear to ear (~16.5 cm)
Access for Neural Monitoring
Area within top circumference of head, which is 63.5 cm [6]
Range of Applicable Force
Apply lbs. of force
Similar Analogies to Key Features
Acknowledgments
We like to thank the ME machine shop staff, especially Toby Donajkowski, John Hall, and Charlie Bradley, for invaluable manufacturing advice.
Pressure Applicator
Quick Release Mechanism
Attachment to Table Mount
Citations
Desai, J. P., Ho, M., Simard, J. M., & Gullapalli, R. (2013). U.S. Patent No. US A1. Washington, DC: U.S. Patent and Trademark Office
Rozet, I., & Vavilala, M. S. (2007). Risks and Benefits of Patient Positioning During Neurosurgical Care. Anesthesiology Clinics, 25(3), 631–653.
Continuum Mechanics - Elasticity. (n.d.). Retrieved October 29, 2016, from Courses/En221/Notes/Elasticity/Elasticity.htm
Classification of Medical Devies." Austrailian Medical Devices Guidance Document 25 (2005): n. pag. Omnex.com. Australian Government Department of Health and Ageing Therapeutic Godds Administration. Web. 30 Oct < iso13485/australia/Australia-Device-Classification-Guidelines.pdf>.
"Brain Injury Foundation." Brain Injury Foundation. N.p., n.d. Web. 30 Oct <
Static adult human physical characteristics of the adult head, from pages of Poston, Alan. (April 2000) Department of Defense Human Factors Engineering Technical Advisory Group (DOD HFE TAG).
ACKNOWLEDGMENTS
Bike seat adjustment mechanism
C-Clamp