All posts by Paul Breedveld

BITE in the news, Media

Octopus-based Instrument used for first time in OR

The ‘mechanical octopus’, a steerable laparoscopic instrument used for minimally invasive surgery in the abdominal cavity, has been used for the first time in an operating room.

Surgeons at the Haags Medisch Centrum are positive about the benefits that the innovative technology in the LaproFlex gave them during a gynaecological operation. The technology behind the instrument was conceived by Paul Breedveld, professor of Medical Instruments & Bio-Inspired Technology. Jules Scheltes, who also obtained his PhD at TU Delft in the field of medical product development and who co-founded the Dutch company DEAM, has been working these past two years to market the product. Following an exciting period, he received CE certification earlier this summer for the LaproFlex and is producing and selling it in Europe.

Paul Breedveld
‘The LaproFlex is an example of research at a university finding its way into industry.’

Jules Scheltes
‘Co-founder Wimold Peters and I are especially proud that we have managed to pull this off with our team. Surgeons have indicated that the instrument is providing them with a better view of the organ they are operating on, and that they can access it from an optimal approach route and are not inconvenienced by intersecting instruments in their field of operation anymore. This is great news. This is exactly what we’ve been working towards.’

What makes this instrument special is that it has a flexible tip. This is made possible by an ingenious steering system based on the anatomy of an octopus’ tentacle, the so-called cable crane mechanism, which ensures that the scissors or grasper can be steered in every direction. Paul Breedveld and the researchers in his Bio-Inspired Technology Group (BITE) have further developed this technology, which has now been globally patented, into a large number of prototypes of steerable surgical instruments. DEAM is a spin-off company of the BITE group that develops steerable precision instruments for minimally invasive interventions. DEAM collaborates with a number of universities of technology and university medical centres. The LaproFlex is the first commercially available instrument using a cable crane mechanism and is considered to be a particularly affordable, disposable alternative for the extremely pricey Da Vinci operation robot.

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Assignments

Design and characterization of a soft gripper for slippery tissue (CLOSED)

Tissue manipulation during surgery is currently done with a grasping forceps. This pinching instrument is prone to errors related to the force that is applied on the gripped tissue. Using too much force may lead to tissue damage.

Inspired by tree frogs, here, we will investigate whether firm but gentle grip on slippery tissue can be generated with grippers containing soft pads. With such a grasper, grip is still friction-based, but does no longer depend on the applied normal load. This probably

In this project, we will implement soft pads into 3D-printed graspers. The grasper design has to be adapted in order to generate load-independent grip. The project includes characterization of a prototype on biological tissues.

Start: January-February 2019

Contact: Peter van Assenbergh, s.p.vanassenbergh@tudelft.nl

MemoSlide, Snake-like Instruments

MemoSlide – Moving like a Mechanical Snake

Developed in 2016-2017, 13 cm wide, 20 cm long, and 10 cm high.

During complex surgical procedures such as in skull-base surgery, there is a need to reach difficult-to-reach locations via narrow anatomic corridors. Performing surgery along complex 3D pathways requires a snake-like instrument able that memorizes the 3D shape of the followed pathway and shifts the shape backward as the instrument moves forward. This snake-like method of locomotion is called “follow-the-leader locomotion”, in which the head is the “leader” and the body follows the pathway of the head, see the following animations:

Follow-the-leader locomotion requires a segmented multi-steerable instrument as well as a memory in which the angles of the segments can be stored and shifted. In robotic approaches, the actuation usually occurs locally, within the segments, by miniature electric motors controlled by a computer. This will, however, result in a device much too large for surgical applications. Alternatively, the actuators can be stored in a handle so that larger motors can be used in combination with steering cables that transfer the motion to the snake-like tip. Although feasible, using electric actuators controlled by a computer will result in a complex and expensive system requiring additional safety measures to ensure reliability during surgery.

In a desire to create a relatively low-cost follow-the-leader system that combines high safety with small dimensions, we explored an alternative follow-the-leader approach by using a mechanical memory inspired by the technology of mechanical calculators such as Charles Babbage’s Difference Engine.

MemoSlide features two mechanical memory registers: a static register (green in the design drawing below) and a moveable register (red) in which the angles of 11 tip segments can be stored, the angles represented by 11 small Ø3 mm ball-bearings that can slide sideways through slots in the brass top plate . The two registers are mutually coupled via a system of ball-bearings and cams underneath the brass top plate. Both registers can be locked and unlocked, and the moveable register can be shifted one segment forward or backward relative to the static register. The position of the first tip segment can be controlled by turning the blue steering wheel. Turning the crank around the steering wheel then results in  a sequence of locking, unlocking and shifting motions, controlled by the four brass cams  at the corners of the device, to memorize and shift the position of the ball bearings backward along the registers. The movie below shows an example in which MemoSlide is programmed with a sinusoidal shape that is shifted backward along the device (and then forward again, as the device works in two directions).

Although in principle suited for controlling the shape of a snake-like surgical device, MemoSlide is in its current configuration still too complex and limited to 2D pathways. Based on our experience with MemoSlide, we are currently developing a new mechanical system suited for memorizing 3D shapes and sufficiently simple for integration in the handle of a snake-like  surgical device. We will keep you posted!

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Media

BITE in the news, Media

Virtual Prototyping

Audio

BRN Dutch News Radio
Programme: Eyeopeners
Presenter: Meindert Schut

 

Ewout Arkenbout, BITE-alumnus, was interviewed by BNR Dutch News Radio about his PhD-research on multi-branched surgical instrumentation, explaining his new “hands-off” design methodology to gain insight in intuitive interfaces for manual steering without constructing prototypes in hardware.

Listen to the interview (in Dutch) via the following link:

Ovipositor Needle I, Steerable Instruments

Ovipositor Needle I – Self-Propelling through Tissue

Developed in 2014, thickness 2 mm.

Wasp ovipositors  are thin and flexible needle-like structures used for laying eggs inside wood or larvae.  Wasp ovipositors are composed out of  longitudinal segments, called “valves”, that can be actuated individually and independently of each other with musculature located in the abdomen of the insect. In this way the wasp can steer the ovipositor along curved trajectories inside different substrates without a need for rotatory motion or axial push.

Inspired by the anatomy of wasp ovipositors, we developed an Ovipositor Needle containing a 2 mm thick “needle” composed out of four sharp and polished stainless steel rods, representing four ovipositor valves. The four valves can be individually moved forward and backward by means of  electromechanical actuators mounted in a propulsion unit that is standing on four passive wheels. If the needle is inserted into a gel that represents tissue, and if the four valves are sequentially moved forward and backward, the friction behaviour around the valves in the gel will result in a net pulling motion that drives the needle forward through the gel. The ovipositor needle is therefore self-propelling, meaning that it does not need a net pushing motion for moving forward through tissue like normal needles do.

Ovipositor Needle I is part of the  WASP project that focuses on the development of steerable needles for localized therapeutic drug delivery or tissue sample removal (biopsy). In a new prototype that is currently under development, we aim to extend the self-propelled needle with steering capabilities at an outer diameter of just 1 mm.

 

Publications

Accessible Prosthetics

TU Delft – Accessible Prosthetics through 3D Printing and a Smartphone App

This research project is part of the Delft Global Initiative program: the portal and booster of Science and Technology for Global Development at TU Delft. Aim of the program is to contribute to sustainable solutions for global societal challenges, through problem-oriented interdisciplinary technical research in close cooperation with partners in the developing world, to meaningfully improve lives of people living in poverty.

NotImpossible-3d-printed-hands-and-arms-1

Combining modern advances in smartphone technology with the seemingly unlimited possibilities of 3D-printing, in this project we aim to create easy access to prosthetics for amputees in Third World countries. We will develop an advanced, free IOS / Android app that scans the amputee with a smartphone camera and completely automates the complex prosthetic design process ending in design drawings for a 3D-printer that manufactures a well-fitting prostheses. In this project we will not only generate new, fundamental knowledge on automatic designing and manufacturing, we will also collaborate with a number of charity organizations to stimulate local initiatives in 3D printing and to optimize the prosthetic supply chain.

Photo: Example of 3D-printed prostheses from Mich Ebelings “Not Impossible Project” in Sudan.

More information: http://globalstories.tudelft.nl/story/paul-breedveld/

 

Tree Frog-Inspired Gripping

NWO – Tree Frog-Inspired Gripping

This research project is funded by the Netherlands Organization for Scientific Research NWO.

Grip between heterogeneous objects can be weak or strong, permanent or reversible, and load dependent or load independent. In some cases, grip needs to be very strong (e.g., aircraft fuselage parts), whereas in other cases it has to be deliberately weak (e.g., screen protection foil for your smartphone). Office tape has to be reversible, whereas a broken vase should be permanently glued back together. A staple can be applied by piercing it through the paper, whereas a surgical gripper should grab soft organs without damaging them.

Grip that is strong, load independent, and reversible at the same time is a great challenge in engineering. Nature, on the other hand, manages quite well: Geckos, for example, can walk on tilted surfaces due to adhesive forces between their toes and the substrate. The stickiness is more than enough to carry the gecko’s weight, but the animal can still easily peel its feet from the surface during walking. Tree frogs can grip on wet, or even flooded, surfaces. Furthermore, their toe pads are soft, thereby eliminating the risk of causing normal stresses to the objects the animal grips upon. With a single foot, tree frogs generate gripping forces strong enough to 100 times carry their weight. Still, tree-frog grip is reversible: The animal detaches from a substrate by peeling its toes off.

The goal of this research project is to gain insight into adhesion on wet and soft surfaces and, inspired by the tree-frog adhesive apparatus, to develop artificial systems that are able to reversibly but firmly grip to objects while minimizing normal stresses.

 

DragonFlex Micro, Steerable Instruments

DragonFlex Micro – Towards the Limits of 3D-Printing

Developed in 2012-2015, thickness 5 mm, steering range: ±90º in all directions, complex components made by 3D-printing.

The DragonFlex has been developed in close-collaboration with Dr. Filip Jelinek, former PhD from the BITE-Group and currently employed at ACMIT.

In follow-up of the successful DragonFlex Macro, the DragonFlex Micro has been miniaturized to a 5 mm scale, where special attention has been given to the reliability and precision of the mechanism and optimization of the 3D-printing technique for such small scale components. Developing and optimising new design methodologies for 3D-printing,  a number of prototypes have been manufactured from different materials, resulting in world’s first steerable surgical instrument made entirely by 3D printing.

 

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