Michael Charles Dahl

Past Research

The first research experience I had involved testing the physiological electromagnetic properties of Ampullary Canals of Lorenzini in bamboo sharks. The ampullary canals are neat little organs that act like electromagnetic band pass filters. These act as a sort of "sixth sense." Instead of dead people, these canals detect the electromagnetic signals produced by the nerves of predators and prey. This project was in conjunction with a experimental physics class I had at the University of Puget Sound. I modeled the canal, then designed and built an apparatus to test the voltage characteristics of the canal tissue in-vitro.

I also assisted Dr. Rand Worland in developing a novel physics experiment to demonstrate the characteristics and theory behind Lissajou patterns. This involved a little guerrilla engineering of a spark table and a double pendulum. This was a lot of fun, even though I got shocked a lot (we were running 30,000 volts through the system, producing a 3 cm arc), but that's what undergraduates are for! If you want to check it out, here is the reference. I'm listed in the acknowledgments.

Rand S. Worland, Matthew J. Moelter. Two-Dimensional Pendulum Experiments Using a Spark Generator. The Physics Teacher . 38, 489-492 (2000).

After my physics degree at the University of Puget Sound, I interned at the Institute of Systems Biology (Dr. Leroy Hood Labs). I worked for the Technology Development team helping to engineer their Ink-Jet microarrayer. The above picture (the one with the ISB in dots) is a DNA microarray arrayed with the arrayer developed there. That's where this whole microarray thing got started.

I sort of carried the topic over to Washington University in St. Louis when I transferred. I was involved in an independent study under Dr. Frank Yin. I was looking for a way to quantify DNA hybridization spots using atomic force microscopy.

Here is some research info on microarrays.

My senior design project at Washington University involved bone remodeling activated by high amplitude low frequency vibration. My team worked with Dr. Matthew Silva to design a prototype that essentually shook mice. It's interesting research, so check out the reference below. Again, I'm listed in the acknowledgments.

Small Animal Whole-Body Vibrational Device

Christiansen BA, Silva MJ. The Effect of Varying Magnitudes of Whole-Body Vibration on Several Skeletal Sites in Mice.  Ann Biomed Eng. 2006. 34(7):1149-56.

I am currently working for the Applied Biomechanics Laboratory under Dr. Randal Ching. My masters project included doing the initial biomechanical testing for the first ever prosthetic intervertebral disk, known as the Bryan Cervical Disk System, made by Spinal Dynamics (now Medtronic-Sofamor-Danek). We tested the dynamic biomechanical properties of the implant, and compared its characteristics to those of a normal and fused spine. Reciently Medtronic-Sofamor-Danek contracted me to do an analysis of the implant core materials for FDA approvial. The results were published in JBE (My first paper!).

Dahl MC, Rouleau JP, Papadopoulos S, Nuckley DJ, Ching RP . Dynamic characteristics of the intact, fused, and prosthetic-replaced cervical disk. Journal of Biomechanical Engineering. 2006. Dec;128(6):809-14.

A side project I did in collaboration with Dr. Sundar Srinivasan incorporated modeling bone formation using a technique called agent based modeling. This is a unique form of computational modeling that examines emergent behavior in a system defined by basic parameters. It allows the researcher to examine the parameter space to determine which characteristics and variables are the most prominent in a system, which allows for more focused empirical research.

A couple neurosurgeons from Harborview Medical Center contacted me about developing a study to determine the difference between various techniques of removing equipment from football players with cervical spine injuries. This was a fun project and the research was just submitted to the Journal of Applied Biomechanics.

Now for my doctorate thesis I am looking at the Agility Total Ankle Prosthesis. I am testing the efficacy of a device I developed that can measure the amount of implant osteointegration non-invasively. I am almost finished with the clinical testing and hopefully will defend in March. As a side project, I am looking at some wear patterns in the prosthesis polyethylene itself using Atomic Force Microscopy.