1. 3-D Larynx Model with Moving Parts
Advisor: Professor William Murphy
Client: Sherri Zelazny
Rexxi Prasasya – Team Leader
Chou Mai – Communicator
Karen Chen – BSAC
Jason Tham - BWIG

2. Larynx Anatomy Transverse arytenoid muscle
contracts
Arytenoid cartilages pulled
Vocal fold closed
Parts of larynx involved in vocalization
Arytenoid cartilages rotate around the vertical axis
Lateral cricoarytenoid
muscles adduct
Vocal fold closed
Adduction (AD)
Abduction (AB)
Anterior-posterior sliding (AP)
Medial-lateral sliding (ML)
(Wesley, 1999)

3. Thyroarytenoid muscle pulls the arytenoid cartilages Vocal fold loosen
High-pitch sound produced
Posterior cricoarytenoid muscle rotates arytenoid cartilages laterally
Vocal cords separate
Cricothyroid muscle rotates the thyroid cartilage
Vocal fold stretched
(Wesley, 1999)

4. Larynx Movement

5. Problem Statement 3-D, automated, functional larynx model
Show anatomical structure of larynx
Animate dynamics of the larynx in sound production
Educational model
Improve understanding of larynx
Assist in planning laryngeal treatments and therapy

6. Available Products Static functional larynx model
Movable arytenoid cartilage and pliable plastic vocal cords
No automation
Visual-aid software program
(Sargent- Welch, 2008)

7. Design Requirements Anatomical Representation Dynamic Representation
Cartilages and muscles present and labeled
Scaling of 3X actual size
Dynamic Representation
Abduction/Adduction of arytenoid cartilage
Flexion/Extension of thyroid cartilage
All muscles associated with cartilage motion

8. Past Achievement Integrated precision motor system
Three reversible electric motors – three cartilage movements
Flexible wires connect cartilages to motors
Increase comprehension of laryngeal function by 36%
The prototype dysfunctional
Plaster cartilages
Silicone muscles
Spring 2008 prototype

9. New Model 3x functional larynx Anatomically accurate movement
Muscles included
Plastic – simple modification
Focus on dynamic automation
Epiglttis, vocal cords, and arythenoid cartilage

10. Arytenoid Cartilage Motion Designs
Rotational string
Ball and socket
Spring and track
(Wesley, 1999)

11. Rotational Spring
Use spring to attach arytenoid cartilage to cricoid cartilage
Attach strings to each cartilage
Strings mimic contraction and motion
Strings attach to motor
Sketch of rotational spring design

12. Ball and Socket Socket implemented on cricoid cartilage
Ball attached to each arytenoid cartilage
Allows “gliding” and “rocking” motions
Sketch of ball and socket design

13. Spring and Track Springs attached to arytenoid cartilages
Track attached to cricoid cartilage
Allows arytenoid cartilages to slide and rock
Sketch of spring and track design

14. Design Matrix 2 1 3 7 9 8 Rotational spring Ball and Socket
Cost (2)
Teaching effectiveness (3)
Motion accuracy (3)
Compatibility / feasibility (2)
Total
Rotational spring 2 1 3 7
Ball and Socket 9
Spring & Track 8

15. Future Work Automate cartilage movement
Implement LED indication of muscle contraction
Create demonstration coordinating motion and sound
Test effectiveness as educational tool

16. References http://www.einsteins-emporium.com
Meyer, J., Roggow, K., Hanson, K., Ladwig, N. Larynx model: final report. 2008
Sargent-Welch Company. 2008
Wesley, N. “The Anatomy Lesson.” Georgetown University