All posts by Aimee Sakes

Design of instruments for veterinary interventions

If you are looking for a challenging assignment that combines bio-inspiration with actual animals, I have currently multiple projects available directed towards veterinary research. The projects are in collaboration with the Rotterdam Zoo and Faculty of Veterinary Medicine of the University Utrecht. Projects are aimed at surgical interventions of different types of animals, including elephants, rhinos, birds, and horses. A selection of the projects is illustrated below:

  • Suturing abdomen of larger animals

Suturing of the abdomen of larger animals is difficult and often results in ripping along the suture line due to the large force on the stitches. This ripping will in most cases lead to death of the animal. Since operations, such as caesarean sections, can be necessary at time to safe both the mother as well as the offspring, a solution should be found for this problem.

  • Design of an stand-up aid for horses after surgery

When horses suffer a bone fracture, the bone needs to be surgically stabilised using screws and plates. In many cases this is done successfully. However, after the horse wakes up after surgery, they are often very tense and tend to panic, which can result in refracture of the bone. The goal of this project is to design a device that can help the horse to stand up safely after the surgery.

  • Design of a bullet removal device in Elephants and Rhinos

In Africa, elephants and rhinos are often hunted for their tusks. Luckily, on some occasions, the elephants and rhinos are able to get away. However, they often sustain severe damage due to bullet wounds. The main challenge the veterinarians face is the removal of these bullets. These bullets are often very deep inside the animal and, therefore, difficult to reach. Furthermore, they often migrate through the body to deeper locations, potentially becoming life threatening. In this assignment, you will develop a bullet removal device for elephants and rhinos that can be used in the field.

  • Design of a tusk extraction device for Elephants

When an elephant’s tusk breaks off, the living tissue inside the tusk will become exposed. If it is not possible to safe the tusk, the best option is to extract it to prevent further harm to the elephant. However, current methods for removing tusks are difficult to perform. Therefore, in this assignment you will develop a new type of instrument that allows for easy and fast task extraction.

  • Design of a smart hatch for animals in Rotterdam Zoo (internship)

In Rotterdam Zoo, they would like to build a smart hatch system for their Wallabies. This system will allow them to keep track of which animal is where and also allows them to capture specific animals with minimal stress.

  • Design of a tusk protection device for Elephants in Rotterdam Zoo (internship)

On some occasions, an elephant tusk might get damaged and a crack may form. On these occasions, veterinarians often place a metal ring around the tusk to protect the living tissue inside the tusk and prevent further damage. However, these rings are heavy and do not offer full protection. Therefore, in this assignment you will design a new type of tusk “ring”.

Contact: Aimée Sakes, a.sakes@tudelft.nl

4TU – Soft Robotics

This programme is a collaboration of the four technical universities of the Netherlands (4TU): Eindhoven University of Technology, University of Twente, Wageningen University, and Delft University of Technology.

Conventional robots operate in pre-programmed environments, enabling the execution of repetitive tasks at superhuman speed and accuracy, based on a design of interlinked rigid segments that are position controlled. A radically different approach is required to enable robots to safely interact with organic matter (which is inherently vulnerable and unpredictable) or to operate in human-inhabited environments. Robots should be soft and compliant, but designing, manufacturing, modelling and controlling them brings many scientific and technological challenges. These challenges have recently begun to be addressed in the emerging research community of ‘soft robotics’.

Our soft robotics programme aims to establish a leading soft robotics community in the Netherlands, that will establish an integrated design approach for soft robotic hardware, control and actuation, inspired by nature. Unlike conventional robots, humans and animals are soft and flexible, and adaptive. While in conventional robots components such as motors, sensors, beams and computer are stacked, in animals functionalities such sensing, control, and actuation are fully integrated, distributed, and robust (i.e., failure of parts does not lead to a non-functional system). In biology the nervous system is distributed over the entire body, and the ‘design’ of the biomechanical motion systems reduces the control demands for the nervous system. For this reason, we want to unravel the solutions found in nature, and use them as inspiration for the design of Soft Robots.

Novel non-assembly 3D printed structures will be explored to integrate electronics and embedded micro-actuators. Additionally, we will investigate bio-inspired power cable structures that can withstand extreme stretch due to their shape. In close collaboration with Wageningen University, we will combine bio-to-techno transfer with techno-to-bio transfer, whereby knowledge of biological functionality is gained from building soft robotic devices.

For more information about this project, please contact Aimée Sakes, a.sakes@tudelft.nl

Design of a Self-Propagating Tree-Root Inspired Needle

Tree roots are able to find their way through the soil towards a water source. They do this by growing their roots in a special way. First, they extend the middle part of the root into the soil. Second, they thicken the roots.

In this assignment, you will develop a soft tree-root inspired needle that is able to propel itself through the body in a minimally invasive way. The challenge will mainly lie in how you can propagate yourself through the body.

If you are interested in this assignment, please contact: Aimée Sakes, a.sakes@tudelft.nl

Tree-Frog Inspired Wall-Climbing Robot

The tree-frog is able to adhere to multiple surfaces. It does this by employing several strategies, one of which is the use of special “suction-cup” feet.

Based on this principle, in this assignment, you will develop a robotic foot inspired by the tree-frog. This robotic-foot can be used for many different applications. Think, for example, on medical applications, where you need to attach and detach quickly, but also on a wall-climbing robot!

If you are interested in this assignment, please contact: Aimée Sakes, a.sakes@tudelft.nl

The Nothern Clingfish, Bio-inspired Suction Cup

The northern clingfish (Gobiesox maeandricus) is able to adhere to slippery, wet, and irregular surfaces in the marine environment. A study by Wainwright et al. (2013) found that the fish can adhere to surfaces with a broad range of surface roughness, from the finest of sandpaper, to highly irregular surfaces such as rocks. The fishes outperform manmade suction cups, which as many of us know, only adhere to smooth surfaces.

Clingfish are able to adhere to these wet and irregular surface due to their highly sophisticated suction disc. This suction disc consists of a cup with at the edge of the cup structured microvilli, similar to those of geckos. When the fish attaches to a surface, water is forced out from under the suction disc by rocking the pelvic girdle and an area of sub-ambient pressure is created. The microvilli at the edge of the disc, subsequently prevent slip of the cup or premature release by creating friction between the cup and the surface.

In this assignment we will focus on the design of a special bio-inspired suction pad for use in medical application to grip and release slippery, wet and soft tissue without damaging the structure.

If you are interested in this assignment, please contact: Aimée Sakes, a.sakes@tudelft.nl

Design of an Innovative Flexible Transport System (Closed)

During percutaneous coronary interventions in the coronaries of the heart, it is often a necessity to remove obstructions from the blood vessels. Obstructions are  removed using specialised instruments, such as atherectomy drills and balloon catheters. During removal, aspiration catheters are used in conjunction with these instruments in order to prevent small particles getting into the blood stream, which can cause a stroke, amongst others. These aspiration catheters use a pressure differential to remove the small particles from the blood stream.

Even though these catheters are successful in removing small particles from the blood stream, they are often plagued by various failure modes. For example, they are prone to clogging and are limited for transport of tissue through long and narrow tubes. Furthermore, the aspiration-force that is created does not only affect the desired tissue but also the surrounding tissue.

Therefore, in this assignment, you will develop a new type of flexible transport system that is not prone to these failure modes.

If you are interested in this assignment, please contact: Aimée Sakes, a.sakes@tudelft.nl

Minimum Assembly Bipolar Instrument

Complex medical devices, such as the EndoWrist, are difficult to manufacture and can often take up to a few week to assemble. In an effort to improve the manufacturability and assembly, in this assignment it is the aim to develop a medical instrument that minimizes assembly.

If you are interested in this assignment, please contact: Aimée Sakes, a.sakes@tudelft.nl

Accura: 8DOF Accurately Steerable Platform

As of today, Chronic Total Occlusions (CTO) represent the most technically challenging lesions interventionists face during Percutaneous Coronary Interventions (PCI), with considerably lower success rates (50-90%) in comparison to semi-occluded and acutely occluded arteries [1]. The main technical challenge in PCI of CTOs lies in successfully puncturing and crossing the CTO with a guidewire.

In this section we will focus on crossing challenges. For solutions to puncture the CTO, see the Pulze Hammer I, Pulze Hammer II (coming soon), Cradle Catheter (coming soon), and Wave Catheter (coming soon).

Crossing is challenging as the guidewire cannot be actively steered and deflection can thus not be compensated. This can lead, amongst others, to dissection of the blood vessel wall or subintimal crossing, in which the guidewire crosses the CTO via the blood vessel wall (between the intima and adventitia). Furthermore, it is often challenging to navigate through tortuous CTOs.

A steerable crossing device could be the solution to current crossing challenges, as it will give the interventionist the freedom to actively navigate through the vascular system and CTO freely. Therefore, a steerable prototype nicknamed the Accura was designed with an 8 Degrees Of Freedom (DOF) cable actuated tip (Ø 2 mm, L = 32 mm) divided over 4 steering segments; allowing for constructing complex S-curves. The tip contains a lumen (Ø 1 mm) to allow for the insertion of, amongst others, a balloon catheter, a guidewire, or an IntraVascular UltraSound probe (for visualization purposes). The steerable tip is connected to a rigid shaft (Ø 2 mm, L = 200 mm), which in turn is connected to the handle. The handle consists of an innovative combined locking and steering mechanism to lock the tip position in place and to precisely steer each segment separately. This construction allows for both the tip position and direction to be changed independently, allowing for a scanning movement.

The multisteerable tip has been successfully combined with a single element forward-looking IVUS transducer and Optical Shape Sensing (OSS) fiber to reconstruct a wire frame in front of the tip. This combination will allow for reconstructing and scanning a 3D volume in front of the tip, which can be used to determine the most suitable entry location. Furthermore, the addition of the OSS fiber can potentially minimize the use of X-Ray and contrast fluid during the intervention.

Even though it is still a long way towards a fully applicable clinical tool, the tests have given first insights into the possibilities and advantages of having such a tool in PCI. Currently, a multisteerable catheter is under development.

Publications:

  • Sakes A., Ali A., Janjic, J., and Breedveld P. (2018). Novel Miniature Tip Design for Enhancing Dexterity in Minimally Invasive Surgery. Journal of Medical Devices. Accepted.

Accura_device2

Volt – 3D-Printed Bipolar Laparoscopic Grasper

Developed in 2016, thickness 5 mm, complex components made by 3D-printing.

Controlling blood loss is a major challenge during laparoscopic surgery. In an effort to control blood loss, electrosurgical tools are often used. In current electrosurgical instruments, a high frequency electrical sinusoidal wave is passed through the patient’s body from an active electrode to a return electrode to minimize bleeding. Depending on the exact configuration of the electrosurgical instrument, it can be used to coagulate, cut, or destroy the tissue.

Even though current bipolar electrosurgical instruments have proven effective in minimizing blood loss, advancement is needed to improve the dexterity and adaptability of these instruments. With current advances in 3D-print processes and its integration in the medical field it has become possible to manufacture patient- and operation-specific instruments. Furthermore, by combining 3D-print technology with smart joint designs, the dexterity of the instruments can be significantly improved.

In order to overcome these challenges, we have developed the first 3D-printed steerable bipolar grasper (5 mm), named Volt, for use in laparoscopy. This 3D-printed design allows for easy adjusting of the geometry of the shaft and tip based on the patient’s anatomy and operation requirements. The grasper significantly improves dexterity by the addition of two planar joints allowing for ±65° for sideways and ±85° for up- and downwards movement. Furthermore, due to smart joint design, high bending stiffness of  4.0 N/mm for joint 1 and 4.4 N/mm for joint 2 is achieved, which is significantly higher than that of currently available steerable instruments. The tip consists of two 3D-printed titanium movable jaws that can be opened and closed with angles up to 170° and allows for grasping and coagulating of tissues. In order to actuate the joint, tip, and electrosurgical system, as well as to tension the steering cables, a ring handle was designed similarly in design to the one of Dragonflex.

In a proof-of-principle experiment, Volt was connected to a electrosurgical unit (Erbe) and was able to successfully coagulate fresh pig liver. Tissue temperatures of over 75 °C were achieved with an activation time of ~5 s.

Publications:

 

 

 

Pressure Wave Catheter for Coronary Interventions

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

Crossing heavily calcified occlusions, such as Chronic Total Occlusions (CTOs), is challenging, resulting in undesirably low success rates between 50% and 90% depending on the operator’s experience and the characteristics of the CTO. The most common failure mode observed in the preferred treatment, the Percutaneous Coronary Intervention (PCI), is the inability to cross the occlusion due to buckling of the guidewire. The inability to cross the CTO often leads to procedural failure and can cause damage to the blood vessel wall.

In order to prevent buckling of the crossing tool and improve the procedural success rates of PCI, we developed a novel, well-working catheter prototype that can apply a mechanical impulse, defined as the integral of a peak force over a small time interval, on the CTO during the crossing procedure. Using an impulse to dynamically load the CTO  is advantageous as the impulse strongly decreases the buckling effect and the static forces on the CTO and its environment, minimizing the risk of damage to the blood vessel wall and the surrounding tissues.

During this TTW demonstrator project we will develop our patented catheter prototype further into a  handheld clinical prototype incorporating an  adjustable tip section as well as a dedicated input mechanism allowing for generating a single impulse as well as continuously vibrating motions. The efficiency and effectiveness of the clinical prototype will be evaluated on CTO models and during ex-vivo and in-vivo animal evaluations.