Auto-suture device for nasal surgery Client: Dr. Benjamin Marcus Department of Otolaryngology Advisor: Professor Tyler Mark Yarmarkovich~Leader Joseph Cabelka~Communicator Jennifer Wager~BSAC Therese Rollmann~BWIG

Problem Statement Develop device to reduce suturing process in nasal surgery (septoplasty) Reduce OR costs ($60/min) The device should mimic the procedure currently used by the surgeon

Design Constraints Reduce suturing time (less than 10 minutes) Autoclavable or one-time use Dimensions must conform to the nose Cost up to $300 for disposable, $1500 for multiple use

Background: Nose Septum: cartilage dividing nose into two chambers; 3-5 mm wide Cartilage Young’s Modulus=10MPa Mucous membrane lining each side of septum Nostril width: 10mm-15mm Flexible

Background: Septoplasty Deviated septum Septum is severely shifted from midline Causes difficulty breathing, sleeping

Background: Septoplasty Incision made to expose caudal end of septum Cartilage excised to prevent overriding Cartilage swung into alignment

Background: Suture Sutures Purse-string suture pattern Close incision Strong, non-toxic polymer fiber Absorbable Purse-string suture pattern Continuous Circular Inverting

Current Device Autosuture devices currently available for bowel surgery Large scale Endostitch Automatic Needle Passer

Materials Autoclavable or one-time use Light weight and easy to handle Durable if multiple use Titanium Composite Stainless Steel Grade 420 Medical Grade Plastic (PEEK) Density 4.42 g/cm3 7.75 g/cm3 1.32 g/cm3 Working Temperature 450°C 400°C 249°C

Design I: Mechanical Needle Passer Needle passed with pulley system Locked into place by notched edges

Design I: Mechanical Needle Passer Pros Mimics procedure Manipulated by surgeon Adjustable number of sutures Cons Many small parts Difficult to manufacture Difficult to autoclave Requires dexterity

Design II: Clamp Clamped on either side of the septum Suture is manually inserted through raised septum

Design II Pros Cons Easy to manufacture Can be disposable Safe Not adjustable to size of nose Not automatic

Design III: Magnetic Needle Passer Magnetic field generated by coils secures needle Switch controls magnetic field activation

Design III: Magnetic Needle Passer Pros Simple mechanism Easy to manipulate Mimics procedure Adjustable number of sutures Cons Magnetic field must generate sufficient force to hold the needle in place Size

Design Matrix Design I Design II Design III Total (50) 35 32 37 Suturing time (15) 11 8 13 Cost (5) 4 5 Manufacturability (5) 1 3 Safety (10) 7 9 6 Mimic procedure (10) Size (5) Total (50) 35 32 37

Future Work Discuss design options with client Build prototype Test device for suture time and ease of use

References Autosuture. 29 January 2007<http://www.autosuture.com>. Azom. 6 March 2007<http://www.azom.com/details.asp?ArticleID=1141>. Cornell. 27 February 2007<http://www.mae.cornell.edu/PDF/mcv3/JB.36.1069.pdf>. Fact Sheet. 2 March 2007.<http://www.entnet.org/healthinfo/sinus/deviated-septum.cfm>. Kortenbach, Juergen Andrew . “Automatic needle-passer suturing instrument .” Patent no. 5,814,054. 1998. Lore, John. An Atlas of Head and Neck Surgery. 1988:Philadelphia. Modern Plastics. 6 March 2007<http://www.modernplastics.com/april05/wdtubing.html>. Septoplasty. 27 February 2007<http://emedicine.com/ent/topic128.htm>. Septum. 7 March 2007 <http://z.about.com/d/p/440/e/f/7166.jpg>.