Credit: FlexDex Surgical
NATIONAL UNIVERSITY OF SINGAPORE
SERIUS RESEARCH PROGRAM
SURGICAL INSTRUMENTS IN MIS
Minimally invasive surgery (MIS) provides an alternative to open procedures, allowing for decreased overall trauma to the patient. Such an intricate surgery, with tools passing through mm-cm incisions, thus calls for increasingly advanced surgical instruments such as graspers, stents, and endoscopes. These devices must be fabricated on a small-scale without compromising flexibility and dexterity
PROBLEM
The current two-point grasper, widely used to physically manipulate tissue, can lead to inadvertent tissue injury. There is a need for highly dexterous, yet small-scale device that can distribute applied forces equally, thereby reducing tissue tears.
APPROACH
Design and prototype an alternate four-point, origami-inspired device.
Fortune Teller- Inspired Device
Why &
What
I chose the traditional fortune-teller design for its four-point grasping capabilities. Increasing the number of contact points implies the possibility of greater force control and distribution.
I modified the original structure with the addition of center folds which effectively increased the number of spherical mechanisms in the system. As a compliant mechanism, increased spherical mechanisms enhanced actuating abilities.
I then prototyped the device through Solidworks, including the center folds/open spaces, and finally 3D printed the design in a flexible polymer.
Triangular Veroclear plastic attachments were also adhered to the each face of the grasper, providing support and promoting movement only at the spherical mechanisms, depicted as the solid dots below. Folds are illustrated with lines.
Prototyping
Actuation Methods
A tendon is knotted through each opposing flat edge of the structure and these two tendons converge at the center of the device on a rod—in this case a paper clip on the left.
When this rod is twisted in either direction, illustrated with a red arrow on the left, the four corners clamp together in an inward and rotating motion.
Conclusions
Overall, these methods and designs take advantage of the relationships between different folds of origami and provide an opportunity and potential for a novel MIS instrument that can increase manipulation and decrease tissue damage.
Over these 8 weeks, I was able to gain experience in product ideation, prototyping utilizing Solidworks, as well develop my trouble-shooting and communication skills as I worked with the Medical Mechatronics Team at NUS. To take this project further, force sensor testing as well as continued iteration to ensure flat-foldability is feasible must be explored!
