MRI Lower Leg Exerciser Team members: Deborah Yagow, Team Leader Colleen Farrell, Communicator Val Maharaj, BWIG Amy Lenz, BSAC Client: Alejandro Roldan Advisor: Naomi Chesler

Overview Problem Statement Project Motivation Client Requirements Competition Design Options Design Matrix Future Work

Problem Statement Design a lower leg exerciser Compatible with: MR imaging Ultrasound Echocardiography Cardiopulmonary research on pulmonary hypertension patients and healthy volunteers Repeatable loads Biofeedback

Project Motivation Researching pulmonary blood flow in hypertensive patients MRI imaging before and after exercise Doppler Ultrasound and Echocardiogram studies possible too Used for patients and normals Pulmonary Arteries in Blue (http://www.cicmd.com/images/cicmd/anatomy%20images/arteries-pulmanary.gif)

Client Requirements MRI compatible Adjustable Patient Scanner Exercise maximal workload and at 40% 30mmHg blood pressure increase Repeatable Ergonomic and comfortable Accurate biofeedback Taken by Amy Lenz

Competition fMRI Mechatronic Ankle Device Lode MRI-compatible ergometer Above: Doane et al., 2007 Left: http://lode.nl/en/products/mri_ergometer_pedal

Design Option #1: Cycle Large muscle recruitment Adjustable resistance Cardio intensive Simple motion for patients Self-generated image

Option #2: Leg Press Simple motion for patients Legs move independently Variable resistance Spring Dashpot Therabands Self-generated image

Option #3: Flexion with Bands Large range of motion for patient Simple construction Interchangeable band resistances Possible lack of consistency Self-generated image

Design Matrix Category Weight of Category Cycle Leg Press Flexion Safety 20 Adjustability 15 10 12 13 Client Preference 8 Effectiveness Price 5 3 4 Durability Repeatability 14 Ease of Manufacturing Total 100 87 83 78

Future Work Write IRB protocol for preliminary ultrasound testing Material research Determine best option for biofeedback Build prototype

Acknowledgements Alejandro Roldan Professor Chesler Dr. Scott Reeder- Dept. of Medical Physics Dr. Bill Schrage- Dept. of Kinesiology

References Doane, D. et al. (2007). fMRI compatible mechatronic ankle device. Technical Design Report. Department of Mechanical, Industrial, and Manufacturing Engineering. Northeastern University. Holverda, S. et al. (2009). Stroke volume increase to exercise in chronic obstructive pulmonary disease is limited by increased pulmonary artery pressure. Heart. Vol. 95: 137-141. Handoko, M. et al. (2009). Opposite Effects of Training in Rats With Stable and Progressive Pulmonary Hypertension. Circulation. Vol. 120: 42-49. Porges, S. (1992). Vagal Tone: A physiologic marker of stress vulnerability. Pediatrics. Vol. 90: 498-504. Pulmonary Artery Image: http://www.cicmd.com/images/cicmd/anatomy%20images/arteries-pulmanary.gif Raymer, H. et al. (2006). Characteristics of a MR-compatible ankle exerciser ergometer for a 3.0 T head-only MR scanner. Medical Engineering and Physics. Vol. 28: 489-494.

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