Week of February 4
In our meeting with Dr. Byram and Emelina, we discussed our options for 3D printing. We explored the most readily available printers, ones on the main campus as well as any in the medical center. Our discussion resulted in identifying three available sources: Featheringill Hall’s Design Studio, the Wond’ry, and one in the Vanderbilt Institute for Surgery and Engineering (VISE) (Medical Center North workspace). But even though they are all printers, each one requires different levels of safety training, as well as providing varying sizes of print beds. Even more impeding is the waitlist to use each machine. Taking each instrument’s characteristics and requirements into account, we decided to utilize the more accessible Design Studio and VISE printers for the actual prototyping and final project, respectively. Because the Stratasys, the model in the VISE workspace, is completely new and located in a pioneering research labspace, the majority of our prototyping would be done with the Design Studio’s.
Also, both Dr. Byram and Emelina approved of the CAD software we are using. A challenge was introduced for our final prototype. Dr. Byram mentioned that we might be able to get access to the VISE space in order to use the brand new 3D printer, which would produce a far better prototype. The problem is that it requires a file conversion from any CAD software to the specific CAD software for that printer. Emelina took the time to show us how to convert it, but it could introduce errors later down the road.
In addition, we have discussed with Dr. Byram which ultrasound probes should fit within the helmet. He suggested that ideally the helmet should be able to support a wide range of probe types, with frequencies ranging from 1 to 4 MHz. Currently, the literature disagrees heavily on what frequencies of ultrasound are optimal for imaging of the cranium, and much of the future work that the Byram lab will be conducting will be focused on finding out which frequencies work better than others. Thus, it is important that the helmet be compatible with a wide range of US probes with differing frequencies, especially in the early stages of the 5-year project. This feature of the helmet will ultimately influence our final design of the prototype.
One potential design solution to accomplish this is to use some sort of molding to cover the ultrasound probe, and subsequently fitting the molded probe into the helmet. That way, if we mold every US probe with the same molding, we can essentially standardize the shape of the probe, making it easier to fit different types of probes onto the helmet. Collaboration with other BME labs, such as the Miga lab, may be a potential option to acquire molding material.
Lastly, we discussed the dimensions of the probe and the possibilities of utilizing more than one probe in our helmet design. This then prompted us to realize that our first prototype should not even be considered to be able to hold different types of probes, as this can be added later on in the semester. Consequently, after discussing with Emelina and Dr. Byram we realized that good probe to start with was the 4V1C Ultrasound Probe. The dimensions of the probe were:
- Depth thin – 7/8’’
- Depth thick – 13/12’’
- Width thin – 1’’
- Width thick – 1.5’’
- Length – 5.5’’
The probe has a thinner portion, located at the neck, which will act as the perfect site to formally clasp the probe. The circumference of this oblique area is about 3.375’’. These measurements will all be apparent in our first CAD design next week.