Megan O'Brien

PERFUSED 3D TISSUE BIOREACTOR

More details (and photos) to come...

PRECISION DESKTOP LATHE

Class Project - 2.720

This design was part of a class at MIT called 'Elements of Mechanical Design'. Each team of 5 was tasked with designing, modeling, fabricating, and testing a precision desktop lathe.

In addition to learning about many principles of precision machine design such as error budgeting, concepts of accuracy, resolution and repeatability, and exact constraint design, we also had to rigorously apply principles of mechanical engineering, physics and math in order to accurately model the expected performance of the system. Our error modeling had to account for stiffness of structures and joints, machining tolerances, thermal effects, and the dynamic response of the machine.

For this project, I was the CAD and FEA 'guru' for the team. My main contributions were the design of the three flexure bearings used, thermal modeling of the machine, and finite element analysis of the flexural components of the system.

KINEMATIC COUPLING
CAMERA MOUNT

An exact constraint design achieves a specific motion, or lack thereof, by applying the minimum number of constraints required to constrain the undesired degrees of freedom of

an object. Using the principle of exact constraint design, kinematic couplings provide a simple and low-cost method to constrain the position between two mating objects with high accuracy and repeatability.

In order to get acquainted with one of the machine shops at MIT, I made a planar ball-and-groove coupling so that I can easily connect my camera to different stands and tracks.

CAMERA SLIDER

Personal Project

Started in December 2015

Pictures of the finished product and a test video to come....

TENDON BIOREACTOR

My project consisted of the design and assembly of a multi-axis bioreactor and low-oxygen system to support tendon conditioning investigations at the Swiss Federal Institute of Technology in Zurich, Switzerland.

The bioreactor had to provide mechanical stimulation, a method for nutrient and gas exchange, space for up to ten tendon samples, and had to offer the ability to adjust the tension of each specimen individually. The key challenge behind this design was maintaining sterility while still meeting these functional requirements.

PORTABLE THERAPEUTIC HYPOTHERMIA DEVICE

As a 3rd year design project, our team developed a concept for rapidly inducing hypothermia in patients who have suffered cardiac arrest or stroke. Therapeutic hypothermia is known to reduce the brain's metabolic rate, therefore decreasing its oxygen requirement and reducing the likelihood of long-term brain damage.

To efficiently remove heat from the patient, our design targets the major vessels supplying blood to the brain. The carotid is of key interest because it carries a high volume of blood, lies relatively close to the surface of the neck, and is often assumed to be the same temperature as the brain due to the high blood perfusion rate in brain tissue.

We're in the process of filing for IP protection, so unfortunately, I can't dish the details (yet)!

Cell culture is an important molecular biology tool that allows in-vitro studies to be conducted prior to expensive and time consuming in-vivo experiments. Two-dimensional cell culture where cells are grown in a monolayer on a dish has been the standard technique since the inception of cell culture. However, this technique poorly mimics the in-vivo environment because of a lack of cell-cell interaction and the dynamic conditions that cells experience in-vivo, resulting in poor physiological predictions. It has been acknowledged that this does a poor job of replicating the anatomy and physiology of tissues found in the body. Three-dimensional cell cultures more closely replicate in-vivo conditions and have been investigated by several groups in recent years. Media perfusion systems have been developed to provide a dynamic system technique for cell growth. The coupling of perfusion and 3D cell culture results in a closer representation of the in-vivo environment, resulting in experiments being able to measure more realistic cell responses.

In collaboration with the Dana Farber Cancer Institute, we have developed a standardized perfusion bioreactor system that enables low-cost, easy-to-use, high throughput cell and tissue culture.