Thursday, August 27, 2015

Closing Remarks!

This summer proved to be one full of new discoveries, learning many critical aspects of conducting research, and coming to appreciate the twists, turns, and new avenues to go about accomplishing academic goals!

Final Summary: Overall, our objective was to assess healthcare workers in their work system and gain an understanding of the acceptance and usage of technology to improve safety and quality of care. Also, to use a human factors approach to develop human machine interface for selected fluid power systems (test bed 4) that are user-centered, safe, easy, and comfortable to use. 

As a result, we were able to gain participants (CNAs, managers, nurses, and trainers) to be interviewed and receive a first-hand understanding of the current work system in a health care environment. This helped us understand the process by which new technology is introduced, received, and implemented within the system! With more time, we could have further assessed and suggested methods of process improvement, safety enhancements, and overall user-centered system design advancements. Either way, we ended with a great foundation for moving forward with future work!

As for me, I learned many fundamentals that research entails: How to approach writing a dissertation, conducting literature reviews, creating a research poster, and learning to adapt to any curve balls along the way! Advice I would give to future CCEFP participants would be to keep an open mind and be ready to take on challenges out of your comfort zone! There may be many unexpected encounters that could lead you in different directions with your work that may prove to be great additions you may not have initially considered!

All in all, I wish everyone the best and want to thank the CCEFP program for a great experience and insightful exposure to the world of fluid power!

Tuesday, August 18, 2015

Seth's Final Post

In summary of the project:  we attempted to quantify the efficiency of a pneumatic strain energy accumulator as an individual component and as part of a system, and to design a test rig for later fatigue testing.  We achieved the first goal of measuring the component’s efficiency and are currently drafting a journal paper but for lack of hardware, we couldn’t measure the system-level efficiency.  The third objective, designing fatigue rig, has been delayed due to difficulties in using a necessary field-programmable gate away (FPGA) input-output device, but with more time even this can be overcome.  It is our hope to complete the journal paper within the next few weeks, the system setup in the next few months, and to have a fatigue demonstration up and running by spring.

All things considered, the research process went very well.  The graduate student managing the project was very well organized, displayed a good sense of judgment, and managed the team well.  My research partner and I worked together well and divided up tasks suitably – most of my time involved programming a post-processing code in Matlab to interpret the data we received during the component test while my partner worked on making sure the hardware functioned properly.  We both spent considerable time learning about different kinds of pneumatic valves and trying a few out in our setup.  When he left for vacation, I started programming an FPGA device in LabVIEW to better accommodate the design specifications for the fatigue test setup.  The primary investigator was also very helpful and met with us often to check on our progress and offer recommendations.  It was a privilege to conduct research at Vanderbilt this summer!

I walk away from this project with skills I didn’t possess coming in:  programming experience in Matlab and LabVIEW; experience with input-output devices and FPGAs; an appreciation for detail, which has helped me solve quite a few problems during my summer research; and a better feel for the demands and work environment of graduate programs.  I’ve also met many invaluable colleagues with whom I would be happy to work with again.  For any new REU participants, I’d recommend: pay attention to detail and don’t be afraid to take initiative.

Saturday, August 15, 2015

Angelica Price Final Post

If your forgot what it is that I have been working on over the summer, well it all seemed to come together towards the end.  I have been working on needle optimization for target trajectory.  At the end of the three needles that were made and tested for their shape setting accuracy it turned out that the needles themselves did not match up to the patients we were trying to match them too, but they were good helical needles and since we could measure their torsion and curvature they could be used with the robot, which is the most important part.

After the needles were tested, we were supposed to go and do some experiments within the MRI machine to see how accurately the pneumatic stepper motor was working to reach a desired target, but towards the end of the summer there seemed to be some issues with our forward kinematics, and the tests had to be pushed back to later this week.

On the upside, my mentor Dave contacted me and stated that he had conducted some experiements within the MRI scanner and it had hit the four targets! Which means the accuracy of the robot is doing well!!

As part of my studies, I have an art and design minor with a focus on graphic designing. Besides working with 2G (project number), I noticed the lab didn't really have a logo, and the website was way out of date, so I created a new logo and website that was easy to manage. I also created a summary video for the general public about 2G. Links are at the bottom for the Laboratory for the Design and Control of Energized Systems website and Youtube channel, more videos to come of course!

It is sad to no longer be in Olin (Pictured above), but it was an absolutely amazing experience. One thing that I really valued during my experience at Vanderbilt was to see their great collaboration with surgery, they even have a whole section called Vanderbilt Initiative in Surgery Engineering (VISE), which I strongly encourage you all to go check out some of the different research being conducted. I was not the only intern working on this project and because he received his opportunity through VISE, I got to be involved in his intern program and he got to watch all of our webcasts and learn about the CCEFP. It was nice to in a ways "double dip" in the experience.  I learned so much about the medical device part of engineering and realized that though it does have to do with medical things, it is not exactly considered biomedical. Honestly I didn't meet a single person that was biomedical but instead met many mechanical and electrical engineers who collaborate a lot with doctors.

I am really glad I had a lab that was willing to answer all of my questions about grad school and that made our work environment enjoyable to be in, and were able to teach me so much about research. They also provided excellent friendship in a place I knew nothing about. They made sure I didn't starve by telling me the best places to eat and even taking me to buy groceries because the grocery store was far.

I honestly can not express to you all the gratitude I have towards the CCEFP for giving me such an amazing opportunity. Thank you to my great mentors, because even though I was assigned to one grad student mentor, it felt like I had 4.

Friday, August 14, 2015

Final Posting

There were two main objectives this summer:
1 - to design a pressure sensing circuit/housing
2 - to reduce the form, weight and profile of a power transfer mechanism for the PPAFO.

The circuit design and testing went very quickly early on in the project.  The most challenging part was designing the housing to work around the limitations (poor tolerances/shrinkage/expansion/rough surface finish) of a the Cura Lulzbot Mini 3D printer we were using.  After a few iterations adjusting the initial dimensions the two halves of the housing fit into each other and around the circuit board.

A second challenge was getting the push to connect fitting to seal around the barbed fitting of a component we were using.  Eventually, wrapping silicon tape around the barbed fitting ended up solving this problem.

The second objective took longer to complete.  First, gear size was optimized.  THe optimization was a challenge in itself.  Because of an inverser relationship between the expected weight and expected stress in the gear system, gear geometry themselves had to be designed to minimize stresses.  In the end we settled on 16 diametral pitch gears with a 35o pressure angle for their high tooth strength.

Material selection was another challenge detailed in the last post.  AR500 steel was the best solution given all the project requirements (cost, preformance, ease of manufacture) but not the best solution for performance alone.

Some parts were outsourced to the UIUC machine shop, others machined ourselves, and others produced via SLA additive manufacturing.  Below is the final system assembled (minus linear actuators & orthotic footbed)
Two nuts were on backorder from McMaster for several weeks and were never delivered.  This prevented attachment of the actuators. Once the nuts arrive, they need to be milled to .25" thickness and mounted to the gear mechanism with the actuators.  Once the acutators are attached, testing can commence.  Strength of the SLA gearbox can be evalueated, and, if need be, the gearbox can be milled from an aluminum block.

In the future, work with wire EDM tolerances and post machining surface treatment (polishing, electropolishing, etc.) might be necessary for gear system with better longevity -- the better the tolerances for gear meshing, the more even the load sharing between gear teeth, thus the longer the gear life.

Additional future work might involve designing a printed circuit board for use with surface mount components on the pressure sensing circuit to further reduce size and weight of the whole board and housing assembly.


I am so grateful to the lab for teaching me throughout the summer and allowing me to work on the orthosis.  After a summer learning about machine design and implementing a design myself, I am amazed at the tolerances to which so many components are mass produced on a daily basis.  It is baffling to think about the amount of work that goes into any engineered object -- not only on the individual components but on the effort it took over generations to accumulate the immense body of engineering knowledge which allows the components to be built in the first place.  This summer I was allowed to reiterate a design that has been in the works for several years.  I hope I have the chance to do it again.

Thanks to Ziming Wang and Elizabeth Hsiao-Wecksler for helping me through this project.