Aneurysms

1992 - Present

Aneurysms, abnormal expansions of arteries, has been Dr. Raghavan's focus area for the bettter part of his last twenty years.

So how exactly can engineers help in dealing with aneurysms? You'd be surprised. In some sense, aneurysms are pressurized membranes that may rupture. And engineers bring to bear techniques in solid and fluid mechanics to improve our understanding of how aneurysms develop and better assess their severity or rupture risk. Not unlike the vey engineering art of assessing the failure risk of a boiler vessel or a decades-old bridge. So, have engineers nailed the problem? Well... that's complicated.... In other words, no. We've come some distance and we've generated a good amount of interest in the medical community, but I can't say we've nailed it. There is no software that will tell if an aneurysm is going to rupture tomorrow. Not yet, at least.

Want more details? See the pages of the lab's current staff and students that focus on this topic - Manasi Ramachandran, Rohini Retarekar, Benjamin Berkowitz, Benjamin Dickerhoff, Anna Hoppe, Aleko Nadareyshvili, Gaurav Sharda, and Timthy Chung

Courses taught by Dr. Raghavan at Iowa that are enhanced by this research: Mechanics of deformable bodies, Biomechanics and Biomaterials, Cardiac and Vascular Mechanics, Advanced Biological Soft Tissue Mechanics.

Cardiovascular Implants and Devices

2002 - Present

The urge to design, build and tinker defines the quintessential engineer. Even the ones adultered by biology and medicine such as yours truly :-) Luckily there is a whole field to sate that thirst - Medical devices.

My lab's interests are:

• study of aortic stent grafts (synthetic tubes used to treat large aneurysms in the chest and abdomen),
• study of coil embolizations (loose wires used to fill up brain aneurysms),
• study of septal occluders (plugs used to block and fill up holes in the heart) and
• design and study of percutaneous heart valve prostheses (artifical heart valves that maybe delivered through a catheter wihtout surgery)

Want more details? See the pages of the lab's current staff and students that focus on this topic - Kathleen Lin, Chaid Schwarz, Aleko Nadareyshvili, Anna Hoppe and Benjamin Dickerhoff

Courses taught by Dr. Raghavan at Iowa that are enhanced by this research: Biomechanics and Biomaterials, Cardiac and Vascular Mechanics, BME Senior design I and II.

Pulmonary Mechanics

2007 - Present

Lung imaging research has long been a major strength of University of Iowa. In collaboration with colleagues in imaging and image processing, my lab uses principles in engineering mechanics to better characterize some aspects of lung function and seeks to use this information to diagnose early onset of lung disease in patients.

Specific research involves development of novel measures of the expansion of the lung during breathing that can shed light on how the lung expands and how this relates to the chest cavity and the diaphragm that it is in contact with.

Want more details? See the page of a graduate student in the lab who focuses on this topic - Ryan Amelon

Courses taught by Dr. Raghavan at Iowa that are enhanced by this research: Advanced Biological Soft Tissue Mechanics.

Mechanical testing of biological soft tissues

1992 - Present

The human body is made of mostly soft tissues (as opposed to hard tissues like bone). Skin, heart, brain, blood vessels, intestine, stomach, kidney, liver, lung, you name it. Some among these perform essential mechanical functions - that is force, constraint and motion are a part of what they do. Think the beating heart and the blood pressure involved, the expanding lungs and the pleural pressure involved, the intestines and their contractions, etc. If we really want to understand their function, we need to understand their mechanical properties.

But biological tissues aren't exactly your everyday elastic bands. They shear and stretch in funny ways. And they change their composition under various situations resulting in funny alterations. How do we test these? We need special ways of testing them. Some interesting research in my lab on this generic area are:

• Design and development of a planar radial extension tester for study of anisotropic planar biological soft tissues whose fiber orientations are unknown a priori.
• Study of the needle penetration properties in an aortic wall - to aid in the design of endovascular devices with improved fixation

Want more details? See the pages of students in the lab who focus on this topic - Andrew Jennings, Ben Berkowitz, Kathleen Lin

Courses taught by Dr. Raghavan at Iowa that are enhanced by this research: Biomechanics and Biomaterials, Cardiac and Vascular Mechanics, Advanced Biological Soft Tissue Mechanics.