00.
PROJECT DETAILS
Role
Research and Development (R&D) Engineering Intern
Tools/Skills
CAD - Fusion 360
Arena QMS
Arena QMS
Timeline
Sept - Dec 2023
Team
MOLLI Engienering Team (~10 members)
01.
CONTEXT
MOLLI Surgical is a medical device company dedicated to the development wire-free lesion localization technology primarily used in lumpectomy procedures (breast cancer surgery). The device eases patient discomfort associated with wire localization biopsy, a conventional technique employed for marking the location of lumps within tissues in preparation for surgical removal.
MOLLI’s device system can be broken down into three components:
MOLLI’s device system can be broken down into three components:
Marker
Marks location of lesion upon insertion into tissue and is detected during surgery
Tablet
Provides visual and auditory feedback of the distance between marker and tip of wand
Wand
Detects location of marker/lesion during surgery
One of my primary contributions to the team was in enhancing consistency among the final builds of the MOLLI wands by minimizing the seam gap between components created during the wand assembly curing process.
The reduction of adhesive failures, which may induce liquid ingress into internal electrical hardware and compromise mechanical fragility, serves as a preventive measure against device malfunction and consequential adversities to the patient.
The reduction of adhesive failures, which may induce liquid ingress into internal electrical hardware and compromise mechanical fragility, serves as a preventive measure against device malfunction and consequential adversities to the patient.
02.
OBJECTIVE
My objective was to design a fixture for the wands which would:
- Inhibit the separation of components bonded by an adhesive during the assembly process.
- Simplify the handling and management of multiple wands.
03.
DESIGN HISTORY
[V0] Initial Design - Simple Rack
General Features:
- enabled storage of multiple wands
- accommodated multiple orientations for curing
Limitations:
- no means to apply compression to seam - device would just “sit” on grooves
- week structural integrity
[V1&2] "Drop Tower"
For context, the wand assembly procedure was completed in two parts, each involving adhesive application. Part 1 ensured that the components of the main body were securely bonded together before the remaining parts were attached during Part 2.
General Features:
- maintained wands in up-right position, allowing the glue to pool at desired locations in the internal body to create a complete seal
- top plate could be tightened against the surface of the wand’s tip to generate compression
Limitations:
- all 10 wands had to be assembled and placed into the jig before applying compression - created discrepancy in the duration that compression was applied on each wand
[V3] Single Spring
To enable control over each wand slot, I experimented with spring-loaded tabs that the operator could lift up while placing the wand into the fixture, then release it to apply compression.
04.
LATEST ITERATION
“ALL-STAR” design - held 5 wands per assembly
Adjustable height - use of hex nuts on threaded rod made tool compatible with various wand lengths
Tabs equipped with 255 degree torsion springs - capable of being lifted by a finger and compressing wand underneath upon release
Press-fit Latches - allowed simple insertion and removal of angled-tip wands into fixture
Various fixture configurations to accommodate a range of wand tip angle, body length, and optimal curing orientation: LEFT - straight tip, tip down, MIDDLE - angled tip, tip down, RIGHT - angled tip, tip up
05.
3D PRINTED PROTOTYPES
06.
RESULTS
The testing of the fixture’s performance with five wand assemblies revealed that it achieved 80% success rate in maintaining consistent seam gaps, even reducing the gap in some cases. With the initial seam gaps being measured at approx. 1mm, it is evident that the fixture effectively reduced the gaps to up to 50% of its original size.
07.
KEY TAKEWAYS
- Never stop innovating
Being surrouded by individuals consistently striving for the "next step" even in the midst of success allowed me to adopt a forward-thinking mindset essential for preserving the impact of ideas.
- Find balance between interoperabiltiy and single-task proficiency
Creating a multi-purposeful product can optimize resource management and manufacturing costs. However, I learned that overloading a product with too many functions can compromise its effectiveness for specialized tasks, essentially diluting its proficiency.
