Auto-Suture Device for Nasal Surgery Client: Dr. Benjamin Marcus Department of Otolaryngology Advisor: Professor Tyler Jennifer Wager ~ Leader Mark Yarmarkovich~ Communicator Therese Rollmann ~ BSAC Joseph Cabelka ~ BWIG

Content Problem Statement Design Constraints Background Spring Semester Design Current Design Future Work

Problem Statement Develop device to reduce suturing time 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 Force sufficient to pull needle through septum (0.8 N) 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 Close incision Strong, non-toxic polymer fiber Absorbable Purse-string suture pattern Continuous Circular Inverting

Previous Design: Electromagnetic Needle Passer Magnetic field generated by coils secures needle Switch controls magnetic field activation Arms are mechanically closed

Electromagnetic Needle Passer: Prototype 22 AWG wire 160 turns per unit length (the whole spool) 4 Amps 0.098N

Average Maximum Force for Salt Pork= lb (0.645 N) sd=0.024 lb Force Testing

New Design: Electro- Mechanical Needle Passer Manual clamping of arms Solenoid actuator locks needle in either side Primarily ABS

Clamping Mechanism Physical force drives needle through septum Spring force pulls needle from septum

Capture Mechanism Etched needle Actuated rod locks needle into place

Actuating Mechanism Linear Solenoid 12 V transformer

Future Work This Semester: Build prototype Test force Next Semester: Test on human tissue

References Autosuture. 29 January Azom. 6 March Cornell. 27 February Fact Sheet. 2 March Kortenbach, Juergen Andrew. “Automatic needle-passer suturing instrument.” Patent no. 5,814, Lore, John. An Atlas of Head and Neck Surgery. 1988:Philadelphia. Modern Plastics. 6 March Septoplasty. 27 February Septum. 7 March 2007.