Senior Design | Mc1026

Speculum Attachment for Lateral Side wall caving

Undergraduate Senior Design Project
Role: Design Team Lead
August 2021 - April 2022

Background

In obese patients and patients that have had many vaginal births, vaginal walls can cave laterally into the field of view of a physician conducting a pelvic exam. This is an issue that occurs from loose excess skin or weakened vaginal muscles. These traits can be observed in many different women, but it is most often observed in bariatric patients or patients who have had multiple vaginal births. During gynecological exams, clinicians insert a medical device called a speculum that will expand the vaginal walls to allow for a clear view of the cervix for potential diagnosis of concerning conditions or for other procedures. In patients with laterally caving walls, however, the view to the cervix is still impeded even with the use of a speculum, leading to potentially undiagnosed health issues leading to further complications such as cervical cancer. Our team's goal for the semester was to develop an attachment for currently approved speculums to address the lateral caving in these patients.

Lead Role Responsibilities

Through group discussion I was chosen to be our Design Team Lead for the project throughout both the Fall and Spring Semesters. As a team lead there are multiple added responsibilities when compared to other members within the group.

Delegating tasks to team members through a project Team Gantt
Compiling and writing formal meeting minutes for all design team meetings
Providing resources and templates for my team to work smarter

Phase 1: Ethnography

The project began with conducting field-based ethnography to find unmet clinical needs in a real world setting. All team members drafted initial ethnography plans and conducted their own research.

I focused my time on a pain clinic within the Falk building under Dr. Trent Emerick. There I noticed an inefficient system of X-ray display positioning, as the displays were across the OR from common injection sites. Through further research, I was able to confirm the unmet need with other sources but it did not align with the scope of the course. Hence, my team took a different direction in women's health.

Phase 2: Ideation

From our focused ethnography into the laterally caving side wall unmet need our team defined the following design criteria:

Must effectively push away vaginal walls
Will not slip out of set correct position
Cannot increase the difficulty to open speculums
Cannot cause more than minimal discomfort to patients

Putting our creativity and design thinking to the test our team conceptualized three design concepts to solve these criteria.

The concept I was tasked to lead was the ring design. This design aimed to add a series of rings to wrap around the speculum and offer adjustable added force.

Phase 3: Prototyping

Continuing on with my responsibility for the ring concept, I planned on fabricating a functional prototype using silicon molding.

Due to the small dimensions proposed for the device, I planned to create CAD files to be 3D printed for the mold.

A reverse mold of silicon proved too flexible for the tight constraint
The printed mold was designed in three components to allow for easy retrieval

Once the molds were printed I was able to utilize SmoothOn Dragon Skin to create a functional solid ring sleeve. When placed on the speculum it stayed perfectly in place and provided minimal additional force to open.

The molding principles applied for the rings will be adjusted to fabricate the team's current balloon design concept.

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Phase 4: Manufacturing

After the Fall semester, the team decided that the balloon concept had the most potential in solving our user needs as the support could be adjusted per the air injected into it. Therefore the molding efforts from last semester needed to be adjusted to create a balloon instead of a sleeve.

Altering the 3D printed CAD files from the sleeve mold I was able to create a 4 piece mold system that would allow for a two-layered ring to be molded and then only need one end to be adhered together.

Utilizing the same Dragon Skin silicon from last semester I attempted to mold several balloon models but time after time the mold was too thin for the silicon to set properly and the balloon would rip when retrieved from the mold. Due to these complications, the team decided that not only was the balloon a complex manufacturing test but also that the molding process proved too variable to produce multiple identical products for testing.

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Phase 5: Verification Testing

Medical products require extensive testing to be done to assure the product specifications are met. For the verification tests, I was assigned to conduct both the Opening Force and Cervix Visibility Tests.

The opening force test consisted of using a force gauge to determine how much the sleeve attachment increased the force needed to open a speculum. Testing demonstrated a consistent 12-newton increase when compared to a condom attachment.

For cervix visibility, the test consisted of using a camera and mock cervix to take images through a speculum with or without the sleeve attachment and measure the area visible. Using ImageJ to analyze the images it was shown that the sleeve increased visibility by 30%.

Regulatory Topics

Having previous FDA regulatory experience I took the role of our team's regulatory strategist. Through FDA database research the following information was found about our device:

Product Code: HIB

Product Classification: Class II

Proposed Regulatory Pathway: Accessory Classification, 513(f)(6) then Premarket Submission,510(k)

Predicate Devices:

ClearSpec Single-Use Vaginal Speculum
Mityview 4-Way Lateral Expander Speculum

In this role, I also collaborated with an FDA Regulation Student to help them draft a 510k and 513g submission for our project.

Design Expo

At the end of both semesters, our senior design class was invited to present our project at the University's Design Expo. To prepare for this event a poster, table display, and video were created to convey our current design concept at the time of each expo, being the Balloon in the Fall and Sleeve in the Spring.

Due to my previous video editing experience, I was in charge of compiling footage of our prototypes and other media to tell our design process story. Using the software Davinci Resolve I was able to create our videos and upload it onto YouTube.

Watch it here!

Fall Video: https://www.youtube.com/watch?v=HlcE_wHs1N8

Spring Video: https://youtu.be/sBWrAJjDxwk

Project Conclusions

Throughout the year-long senior design class for the Bioengineering Department at the University of Pittsburgh, our team was able to design, manufacture, and test a fully functioning Silicon Sleeve device (shown above) that aims to combat a clinical need identified through clinical ethnography. All verification tests proved successful in achieving the user needs defined at the start of the project and the validation process of getting our device into the hands of clinical OBGYN doctors demonstrated their approval and draw to the benefits of the device. The team was able to create a quality system in which a document control system was established to host and organize the necessary files and data to construct a Design History File and European Union Medical Device Record.

Throughout this project I have gained marked experience in conducting clinical ethnography, operating through a design process, FDA/CFR requirements, and the design of experiments. All of these skills I hope to leverage and continue to develop as I graduate at the end of this program and enter the next stages of my professional and academic careers.