All posts by Kirsten Lussenburg

3D-GriP, Steerable Instruments

3D-GriP – A minimal assembly fully 3D printed instrument

Developed in 2020-2021, diameter Ø8 mm, bending angle ±60˚, consists of 5 separate parts.

In minimally invasive surgery, small incision sizes limit the manoeuvrability of surgical instruments. The number of degrees of freedom (DOF) of the instrument shaft can be increased by making the instrument tip steerable. Such instruments are controlled by the surgeon on the side of the handle. Steerable instruments offer many advantages in terms of DOF and functionality, however they have high mechanical complexity, and the steerable shaft can be difficult to operate for the surgeon.

Additive manufacturing (AM) can aid in the development of these instruments by reducing the mechanical complexity in the form of minimal assembly designs. The freedom of complexity offered by AM allows parts to be merged together into larger, more complex parts, that can be 3D printed in a single step. In addition, AM allows the production of one-off, personalized designs.

The 3D-GriP is a 3D printed steerable instrument that consists of only 5 separate parts. The handle part is designed based on ergonomic principles for handheld instruments, and can be adjusted to the size of the surgeon’s hands for a perfect fit. The joystick steers the instrument and works with a passive lock, which is automatically engaged when no pressure is applied. The grasper can be closed with the trigger, designed with two perpendicular flexures, which can be operated by one or two fingers, as the surgeon prefers.

Culmone C., Lussenburg K., Alkemade J., Smit G., Sakes A., Breedveld P. (2021). A fully 3D-printed steerable instrument for minimally invasive surgery. Materials, Vol. 14, No. 24, 18 p. 

Assignments

Miniature Suction Gripper for Eye Surgery (CLOSED)

The eye is made up of delicate tissue, which can easliy be damaged when it is being handled excessively during surgery. The outer layer on top of the eye, called the conjunctiva, is responsible for keeping the eye lubricated. This thin layer is often manipulated during surgery in order to perform other operations, but as a result of hard metal forceps it can become damaged. See this movie for an example.

In this assignment, the aim is to develop a miniature suction gripper that can handle delicate eye tissue during surgery. First you will look into miniature suction grippers for different applications, after which you will design and test a novel prototype.

Interested? Contact Vera Kortman (v.g.kortman@tudelft.nl) or Kirsten Lussenburg (k.m.lussenburg@tudelft.nl)

Assignments

Exploring hierarchical mechanisms (CLOSED)

Imagine a tower build of LEGO, consisting of a number of bricks that together form a new shape. Now imagine that each LEGO brick is a tiny mechanism, in contact with the mechanisms that surround it. What if we can program each individual mechanism with a very simple task, and are able to turn it on or off when we desire. Could we use these tiny mechanisms as cells that create a new, larger mechanism? Can we create a mechanism that is a lawnmower one day, a coffee machine the next, just by switching on or off certain cells?

We want to use the form complexity of 3D printing to create ‘hierarchical mechanisms’, closely related to metamaterials. This is an exploratory assignment, so we are looking for a creative student with an investigative, curious mind. Some inspirational work is shown on this page.

Interested? This assignment is available starting January/February 2021. Contact Kirsten Lussenburg, k.m.lussenburg@tudelft.nl.

Metamaterial mechanisms by Hasso Plattner Institute

Overview ‹ kinetiX — MIT Media Lab
Kinetix Mechanisms by Tangible Media Group

Core Concept: Mechanical metamaterials bend the rules of everyday physics | PNAS
Textured Mechanical Metamaterials by Yair Shokef’s Research Group

Assignments

Non-assembly mechanisms for eye surgery (CLOSED)

Surgical instruments used in eye surgery are very small, which makes it difficult to produce instruments with high functionality. The bottleneck in the production of eye surgical instruments is the assembly step. Assembly has to be done by hand, because of the small size of the parts. Automation is difficult to implement, due to the relatively small number of specific instruments. As a solution to this problem, the complexity offered by 3D printing can be used. A way to do this is to 3D print entire functioning products or mechanism in one single step, without the need of assembling them afterwards, called non-assembly 3D printing.

A vitrectome is a specific instrument used in eye surgery to remove the vitreous from the eye. It consists of two thin, hollow needles that are inserted into the eye, and a handle containing a vibrating mechanism. In this assignment, you will be working on the design of a non-assembly 3D printed vitrectome mechanism, which should have the same specifications as current vitrectomes.

This assignment will be available from January/February 2021. Interested? Contact Kirsten Lussenburg, k.m.lussenburg@tudelft.nl.

3D Printed Medical Devices, Research Projects

EU 3DMED – 3D Printed eye surgery instruments

This research is part of EU Interreg 2 Seas Mers Zeeën 3D MED: Development and streamlined integration of 3D printing technologies to enable advanced medical treatment and its widespread application.

The goal of this project is to research the possibilities of 3D printing for the advanced design and production of medical devices, in order to improve affordability and accessibility of medical treatment. The benefit of 3D printing is that complex shapes can be created in one single production step, which offers great potential for easy manufacturing and added functionality. The focus will be on developing design methods for complex medical devices with internal mechanisms used in eye surgery, which can be printed as one functioning assembly. This research is executed in collaboration with DORC, the Dutch Ophthalmic Research Centre.