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This is a core-extracting
endoscopic biopsy needle designed by a team of MIT graduate students under
the advisement of Dr. William Brugge of Massachusetts General Hospital
and Professor Alex Slocum. The design incorporates a polycarbonate needle
tip, which houses four flexible teeth angled into the needle at a 30-degree
angle. These teeth flex open when the tissue enters, and upon retraction
of the needle, the teeth sever the tissue sample into the needle shaft.
The polycarbonate needle tip is attached to the stainless steel shaft
through a sinusoidal threading and medical grade adhesive. This design
is now patented.
The following show the highlights of our design process.
State of the Art: An endoscopic biopsy
is a minimally invasive means of extracting a tissue sample from a patient.
The current endoscopic biopsy needles are incapable of preserving the
tissue histology and are relatively unreliable. 
Brainstorming Sketches: The
following is a small sample of our original concept sketches.

Sketch Model Testing of Select Concepts: Side-Cutting
and End-Cutting were first tested with straws on layered clay. Brass End-Cutting
Mockups were tested on cow liver.

Detailed Design (SLA prototypes) and Testing:
Our top three concepts were rapid prototyped and tested for preservation
of histology on gelatin samples.

Final CAD Model of Needle Tip
(showing FEA analysis on teeth flexing open and closed):
The final concept was optimized to increase sample quality and ensure
structural robustness through a design of experiments and finite element
analysis.
 
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