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Minimally invasive surgery (MIS) is a surgery technique that is carried out through small incisions in the skin with thin, long instruments. In order for the surgeon to see his actions with his instruments, a small camera with a light source (an endoscope) is used to look inside the person that is operated. MIS, also called laparoscopy when carried out in the abdominal cavity, has many advantages compared to traditional surgery such as less operative trauma and reduced hospitalization time. However, there are many disadvantages as well. Especially for the surgeon a lot of aspects of surgery have become more difficult. The instruments that the surgeon uses are small and have tiny forceps in order to fit through the incisions. A problem that occurs with these forceps is that of not having good grip on the slippery tissue. The surgeon tries to prevent this by using a large pinch force and using forceps that are provided with a saw-tooth profile. The consequence however is that due to these two solutions the tissue sometimes gets damaged. Since a lot of research is done nowadays on adhesives that stick to mucus tissue (mucoadhesives), it is interesting to investigate whether it is worthwhile to design and develop a laparoscopic forceps that provides the grip with the tissue by means of such a mucoadhesive so that large pinch forces and profiles are not necessary anymore. This thesis gives background information on this subject by studying chemistry, physics, patent and biological literature. From physical and chemistry information, insight was gained on the working principles of adhesion in general. For using a mucoadhesive on a laparoscopic forceps in order to manipulate the tissue, the adhesion mechanism between forceps and tissue must be temporary. This adhesion mechanism must be strong enough but must have a quick release or deactivation mechanism as well. From a patent research came forward that there is very little done on the area of manipulating tissue by means of an adhesive. The main problem of using an adhesive to create grip with tissue is how to loosen the adhesive again from the tissue. No patent was found that explained a method of loosening the adhesive again, which confirmed that this is the most important problem that has to be solved to come to a good design. In order to investigate methods for undoing adhesion, research in biological literature was done, because temporary adhesion is something that is used by a lot of animals for instance to walk upside down a ceiling. From a number of examples of temporary adhesion mechanisms a number of release mechanisms were found. From the demands that the release mechanism should suffice to be used on a laparoscopic forceps, two interesting release mechanisms came forward. These release mechanisms, peeling and hydration of the mucoadhesive need further investigation. Overall can be concluded that from the background information presented in this thesis it can be recommended to do further research for the design of a laparoscopic forceps that has grip by means of a mucoadhesive. Peeling of the mucoadhesive or hydrating are the most interesting release mechanisms that could be applied in such a forceps.

Laparoscopic surgery is a technique in which operations in the abdomen are performed with long slender instruments through small incisions (5-10 mm). Single port surgery is a form of laparoscopic surgery with possible advantages in which the surgeon operates almost exclusively through a single incision. In order to compensate for the limited freedom of motion of the used instruments, steerable instruments with articulating tips that can be steered in 2 DOF have been developed for use during laparoscopic or single port surgery. The freedom of motion provided by steerable instruments make single port surgery possible, but however introduces a number of problems (eye-hand coordination conflicts, incision widening). This paper presents the design of a new, multisteerable instrument that can be used for both laparoscopic as well as single port surgery.

Laparoscopic graspers require a high pinch force to generate sufficient friction force (grip) for tissue manipulation. Excessive or insufficient pinch forces distributed along the small contact area of laparoscopic graspers can cause damage and are one of the reasons why the risk of intraoperative complications during Minimally Invasive Surgery (MIS) procedures in the abdomen is 2-4 % higher compared to open surgery. The goal of this research was to develop and evaluate an 5 mm laparoscopic grasper, which has the same functionality (generated friction force, grasping time) as a conventional grasper for use on the intestine but which requires lower pinch force due to the use of adhesives. To lower the pinch force the adhesive component of the friction force was enlarged by introducing a muco-adhesive between tissue and grasper. To lower (local) high pressures a flat surface was used. Two experiments were conducted to find out in which direction the friction force generated by the adhesive film was the largest and to find the minimum required area of adhesive film to generate a force of 5 N. Next, a design for the tip and a design for the adhesive film feed mechanism was made. To evaluate the design a prototype was created, which was used to investigate whether the proposed tip design was able to generate a friction force of 5 N using a pinch force lower than 3 N. The prototype of the adhesive grasper was able to generate a friction force of 3.12 ± 0.58 N, while using a pinch force of 2.5 N. The generated friction force did not meet the goal of 5 N, but the concept of lowering the pinch force by introducing an adhesive layer is promising; the pinch force needed by the proposed tip is lower compared to existing graspers and the friction force was independent of the generated pinch force. The friction force can be increased further by developing a new adhesive film or by increasing the contact area.

Background During eye surgery in patients suffering Age Related Macular Degeneration translocating a graft of tissue without damaging the vulnerable top layer is highly problematic using the currently available instruments. This study presents indirect Heat Induced Attachment and Detachment (HIAD) as a new concept for single side tissue attachment and detachment to improve translocation of the graft. Method A micro scale prototype with an electrically heatable wire was built that heats the instrument-tissue interface indirectly. To study the attachment and detachment properties of the prototype a series of tests was performed on chicken meat. The electric signal applied on the prototype was a 9V DC signal for amplifier input signal lengths varying from 0.6-1.5 ms. Results Attachment and detachment occured with 98% and 90% certainty with 41 mJ and 110 mJ energy supplied to the prototype tip in 0.7 and 1.5 ms respectively. The attachment strength was estimated as at least 0.2 mN. Macroscopically, visible damage appeared to be ≈ 0.005 mm². Conclusions The principle of indirect heating of the instrument-tissue interface proved to be effective as a prototype with an electrically heatable wire could induce attachment and detachment of tissue. Indirect Heat Induced Attachment and Detachment may be applicable in many different surgical applications.

In the last thirty years, many new surgical methods and techniques such as laparoscopic surgery and natural orifice surgery have been introduced into hospitals worldwide. As these technologies have progressed, surgical instruments have become increasingly more complex and also much more difficult to clean and sterilize. In this paper, one such instrument, a steerable laparoscopic grasper which is currently too complex to clean and sterilize in a hospital, is examined in detail. The challenges which prevent this instrument from being properly cleaned are identified, and a new novel design concept to neutralize these challenges is suggested. In addition to this, cleaning and sterilization guidelines and strategies which can be applied to any surgical instrument are presented.

Endo-Nasal Skull-Base Surgery (ENSBS) is preformed at the area around the base of the skull and has great advantages compared to Open Skull Base Surgery (OSBS). Due to limitations in surgical equipment, ENSBS is not always a viable option. This research attempts to address these limitations through the development of a highly manoeuvrable, actively controlled, shape memory instrument. A design of such an instrument is proposed which achieves shape memory control through remote cable actuation. Motions are transmitted from a series of segments in the handle, to identical segments in the tip of the mechanism. The design includes a fully mechanical shape memory mechanism incorporated inside the handle which should allow the tip, through motion transition from the handle, to follow a custom defined path in space. The design has been prototyped on large scale and its working principle evaluated. Results showed a design flaw with respect to cable motion in the handle. This flaw was caused by the applied steering principle and sequence of segment cable connections. Partial validation of the feasibility of a fully mechanical highly manoeuvrable instrument with shape memory control has been achieved, and increased understanding into the design working mechanism has been obtained. Finally, a redesign of the original concept is provided, including a discussion on the opportunities for miniaturization, and an analysis into the additional necessary future developments for this instrument.

The current method of minimally invasive harvesting the sural nerve in infants takes too much time. To reduce harvesting time a new Minimally Invasive Nerve Dissector (MIND) was designed. The MIND reduces instrument change by combining the two most used functions of the currently used instruments: firstly, the movement of the graft with the hook and secondly, the outwards motion of the micro scissors. Besides these two functions, the MIND was designed for a minimally invasive procedure and is much smaller than the current instruments. The MIND was evaluated on an artificial test facility simulating a leg of an infant. Using the test facility a test comparing the current instruments and the MIND was carried out. Measured were the time to harvest and the number of dissection instrument changes. The results of the test showed that both showed positive improvements with the MIND.

A major problem in keyhole surgery, which involves surgeons performing operations through small incisions, is the complex manoeuvring of small instruments. Researchers at TU Delft have built an entirely new tool tip control system, based on the tentacles of squid that will enable surgeons to manoeuvre a camera or instrument in any direction during keyhole surgery. The concept uses nothing but standard parts like cables, springs, washers and tubes, so the cost is less than one percent of the cost of the currently available tool tip systems. The mechanism is easy to miniaturise. A worldwide patent has already been applied for, and the design is now ready for commercial application. Surgeons cant wait to start using the new invention, in particular because it will enable them to use minute instruments during keyhole surgery.

Malignant colonic obstruction is a severe complication of primary colorectal carcinoma. Patients presenting this clinical condition develop tumors that obstruct the lumen of the intestinal tract. The treatment of this medical complication is aimed to re-establish the normal pass of fecal mass through the colon. One of the current treatments includes the insertion of a self-expandable meshed metal tube (stent) along the obstruction. By deploying the stent, the obstruction is opened, allowing the passage of fecal mass. Despite its advantages, stent placement is associated with a number of medical complications. The literature shows that colonic stent migration is the most common stent related medical complication. This paper studies the factors that influence colonic stent migration and explores new possibilities to anchor a colonic stent to the bowel. In vitro experiments show that providing the colonic stent with an appropriate fixation mechanism, decreases the chance of colonic stent migration. The results suggest that the friction forces in the interface between the stent and the colonic wall increases, if the stent is provided with a fixation mechanism.

Colonic cancer is the second leading cause of death among cancers in the Western world. Early detection greatly improves the chances of survival. Colonoscopy is a non-invasive detection method through natural access, making it possible to look inside the colon, take biopsies and remove small polyps that can develop into cancer. Colonoscopy is often experienced as a painful and uncomfortable procedure. A cause for the pain a patient experiences is the buckling of the colonoscope, a long, lighted tube with camera and biopsy canal, that stretches the colonic wall. This buckling occurs because the colonoscope has to take difficult bends while being pushed from behind. In order to prevent this buckling, a device is presented that pulls the colonoscope from the front. The presented design is that of a device that uses a rolling mucoadhesive films to create friction with the colonic surface to pull itself forward into the colon. A demonstration model was constructed and tested in vitro in the colon of a pig. Tests showed that it is possible to move a device through the colon by using a rolling mucoadhesive films. It can be concluded that the presented design is a step forward to come to an improved design of a colonoscope that is not only pushed from behind but also pulled forward from the front.