J. J. van den Dobbelsteen
Delft University of Technology
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Featured researches published by J. J. van den Dobbelsteen.
Surgical Endoscopy and Other Interventional Techniques | 2007
J. J. van den Dobbelsteen; A. Schooleman; Jenny Dankelman
BackgroundIn minimally invasive surgery, force feedback information on tissue manipulation is altered by friction between the instrument and the sealing mechanism of the trocar. It is unknown how the different sealing mechanisms of currently available trocars influence the friction forces. The current study investigated the dynamic changes in friction for various trocars at different instrument velocities.MethodsThe friction characteristics for six common types of trocars were determined. A force sensor was attached to the shaft of a standard 5-mm disposable grasper to measure the forces required to move it through the trocars. Movement velocity and direction of the shaft were controlled by a servomotor. In addition, whether moistening the shaft reduced friction was tested.ResultsThe friction depended on the type of trocar, the movement velocity, and the movement direction, and varied between 0.25 and 3.0 N. Specifically, trocars with narrow sealing caps (i.e., high normal force onto the shaft) and trocars with thick sealing caps (i.e., large contact area) generate a high amount of friction. Moistening the shaft reduced friction 15% to 45%. For most trocars, large fluctuations in forces occur when the movement starts or when the direction reverses. The magnitude of these fluctuations varied between 0.2 and 2.5 N.ConclusionsFor some trocars, friction can be as great as the forces associated with instrument–tissue interaction. At movement reversals, friction fluctuates due to deformations of the rubber and silicon parts of the sealing mechanism. Such high variance can deteriorate surgical performance during high precision tasks (e.g., tissue manipulation) that typically involve many changes in movement direction. Comparisons of the investigated trocars indicate that the friction magnitude and variance can be reduced easily by changing the properties of the sealing cap or by lubricating the instruments.
British Journal of Surgery | 2014
S. P. Rodrigues; Tim Horeman; P. Sam; Jenny Dankelman; J. J. van den Dobbelsteen; Frank-Willem Jansen
Force feedback might improve surgical performance during minimally invasive surgery. This study sought to determine whether training with force feedback shortened the tissue‐handling learning curve, and examined the influence of real‐time visual feedback compared with postprocessing feedback.
Surgical Endoscopy and Other Interventional Techniques | 2016
Sharon P. Rodrigues; Tim Horeman; M. S. H. Blomjous; E. Hiemstra; J. J. van den Dobbelsteen; Frank-Willem Jansen
BackgroundThe aim of this study was to examine the influence of training under direct vision prior to training with indirect vision on the learning curve of the laparoscopic suture task.MethodsNovices were randomized in two groups. Group 1 performed three suturing tasks in a transparent laparoscopic box trainer under direct vision followed by three suturing tasks in a standard non-transparent laparoscopic box trainer equipped with a 0° laparoscope. Group 2 performed six suturing tasks in a standard laparoscopic box trainer. Performance time, motion analysis parameters (economy of movements) and interaction force parameters (tissue handling) were measured. Participants completed a questionnaire assessing: self-perceived dexterity before and after the training, their experienced frustration and the difficulty of the training.ResultsA total of 34 participants were included, one was excluded because of incomplete training. Group 1 used significantly less time to complete the total of six tasks (27 %). At the end of the training, there were no differences in motion or force parameters between the two groups. Group 2 rated their self-perceived dexterity after the training significantly lower than before the training and also reported significantly higher levels of frustration compared to group 1. Both groups rated the difficulty of the training similar.ConclusionNovices benefit from starting their training of difficult basic laparoscopic skills, e.g., suturing, in a transparent box trainer without camera. It takes less time to complete the tasks, and they get less frustrated by the training with the same results on their economy of movements and tissue handling skills.
Ultrasound in Obstetrics & Gynecology | 2016
E. Araujo Júnior; Alex J. Eggink; J. J. van den Dobbelsteen; Wellington P. Martins; Dick Oepkes
To assess and compare the rate of procedure‐related complications after intrauterine treatment of spina bifida by endoscopic surgery and by open fetal surgery.
Journal of Medical Devices-transactions of The Asme | 2014
H. C. M. Clogenson; Jenny Dankelman; J. J. van den Dobbelsteen
In endovascular interventions, thin, flexible instruments are inserted through the skin into the blood vessels to diagnose and treat various diseases of the vascular system. One drawback is that the instruments are difficult to maneuver in the desired direction due to limitations in shape and flexibility. Another disadvantage is that the interventions are performed under intermittent fluoroscopy/angiography imaging. Magnetic resonance imaging (MRI) may offer advantages over X-ray guidance. It presents a good soft tissue contrast without the use of nephrotoxic media or ionizing radiation. The aim of this study is to develop a guidewire that is compatible with MRI and includes a steerable segment at the tip. This added degree-of-freedom may improve the maneuverability of the devices thereby the efficiently and safety of the navigation. A 1.6 m (5 ft, 3 in.) long and 0.035 in. diameter guidewire that consists of MR compatible materials and has a flexible tip was designed. The only metallic part was a nitinol rod that was implemented at the distal flexible tip. To limit the risk of heating in the MRI, this rod was kept shorter than 30 mm. The tip could be deflected in one direction by pulling on a Dyneema wire that was placed in the lumen of the shaft of the guidewire. To drive the steerable tip, a handle that could be easily attached/detached from the instrument was designed and implemented. Using the handle, the tip of the 1.60 m long guidewire prototype could be actuated to reach angles from 30 deg to 250 deg. The handle could easily be placed on and removed from the guidewire, so conventional 0.035 in.–compatible catheters could slide over from the proximal end. However, in order to make the guidewire more efficient to enter a bifurcation, the stiffness of the tip should progressively increase from its proximal to its distal end. The guidewire was imaged in a 1.5T MRI using real-time imaging without producing artifacts that would have shaded the anatomy. It was possible to assemble a guidewire with a steerable segment in the required size, using MR compatible materials. Therefore, the current design is a promising proof of concept and allowed us to clearly identify the features that need to be improved in order to come to a clinically applicable instrument.
Surgical Endoscopy and Other Interventional Techniques | 2015
Sharon P. Rodrigues; Tim Horeman; Jenny Dankelman; J. J. van den Dobbelsteen; Frank-Willem Jansen
AbstractBackgroundA study was performed to determine differences in applied interaction force between conventional open surgery and laparoscopic surgery during suturing in a non-clinical setting.MethodsIn a laparoscopic box trainer set-up, experts performed two intracorporeal and two extracorporeal sutures on an artificial skin model. They also performed two instrument-tie knots and two one-hand square knots in a similar conventional training set-up. The force exerted on the artificial tissue (mean force, mean non-zero, maximum, and volume) and the time to complete a task were measured. For analysis purposes, sutures are divided in a needle driving phase (Phase 1) and knot-tying phase (Phase 2). ResultsPhase 1: Force values in laparoscopic suturing are significantly higher than in conventional suturing, except for the force volume during extracorporeal suturing versus the one-hand square knot. Phase 2: The mean force non-zero and maximum force during the intracorporeal knot are significantly higher than during the instrument-tie knot. The mean and maximum force during the extracorporeal knot are significantly higher than during the one-hand square knot. Furthermore, laparoscopic suturing takes longer time than conventional suturing.ConclusionExpert surgeons apply significantly higher force during laparoscopic surgery compared to conventional surgery even though the same strategy is used. Aspects such as the limited visual and haptic feedback, and movement possibilities hamper surgeons’ ability to assess the applied interaction force. Therefore it can be useful to provide additional force feedback about the applied interaction force during training in non-clinical settings.
Surgical Endoscopy and Other Interventional Techniques | 2013
N. J. van de Berg; J. J. van den Dobbelsteen; Frank-Willem Jansen; C. A. Grimbergen; Jenny Dankelman
BackgroundEnergy administered during soft-tissue treatments may cauterize, coagulate, seal, or otherwise affect underlying structures. A general overview of the functionality, procedural outcomes, and associated risks of these treatments, however, is not yet generally available. In addition, literature is sometimes inconsistent with regards to terminology. Along with the rapid expansion of available energetic instruments, particularly in the field of endoscopic surgery, these factors may complicate the ability to step back, review available treatment options, and identify critical parameters for appropriate use.MethodsOnline databases of PubMed, Web of Science, and Google Scholar were used to collect literature on popular energetic treatments, such as electrosurgery, plasma surgery, ultrasonic surgery, and laser surgery. The main results include review and comparison studies on the working mechanisms, pathological outcomes, and procedural hazards.ResultsThe tissue response to energetic treatments can be largely explained by known mechanical and thermal interactions. Application parameters, such as the interaction time and power density, were found to be of major influence. By breaking down treatments to this interaction level, it is possible to differentiate the available options and reveal their strengths and weaknesses. Exact measures of damage and alike quantifications of interaction are, although valuable to the surgeon, often either simply unknown due to the high impact of tissue and application-dependent parameters or badly documented in previous studies. In addition, inconsistencies in literature regarding the terminology of used techniques were observed and discussed. They may complicate the formulation of cause and effect relations and lead to misconceptions regarding the treatment performance.ConclusionsSome basic knowledge on used energetic treatments and settings and a proper use of terminology may enhance the practitioner’s insight in allowable actions to take, improve the interpretation and diagnosis of histological and mechanical tissue changes, and decrease the probability of iatrogenic mishaps.
BMJ Innovations | 2015
Linda Wauben; Annetje C. P. Guédon; Dirk F. de Korne; J. J. van den Dobbelsteen
Objective Measure wait times, characterise current information flow and define requirements for a technological information system that supports the patients journey. Design First, patients were observed during eight random weekdays and the durations of actions performed at each phase of the surgical trajectory were measured. Patients were grouped into patients receiving general anaesthesia or local (or topical) anaesthesia. Second (active) Radio Frequency IDentification (RFID) technology was installed and patients were tracked during 52 weekdays. Length of hospital stay, length of stay and wait times per phase, and differences in wait times between the two types of administered anaesthesia were analysed. Third, interviews were conducted to characterise the current information flow between staff, and between staff and escorts (patients’ family/friends escorting them throughout their journey). Results Observations (198 patients) showed that the average duration of actions for general anaesthesia patients took longer than for local anaesthesia patients, especially at the recovery phase (general anaesthesia: 0h16, local anaesthesia: 0h01). RFID tracking (622 patients): Significant differences were seen for wait times between general and local anaesthesia patients at: preoperative ward (p=0.014), recovery (p<0.001) and postoperative ward (p<0.001). The average percentage of wait time during the entire hospital stay ranged from 64% to 68% (with variation in groups being substantial). Interviews (30 escorts, 9 ward nurses and 8 holding/recovery nurses): Escorts did not use the current information system and ward nurses indicated problems with exchanging information concerning bringing/picking up patients to/from the holding/recovery that resulted in unnecessary wait times for some patients (mainly local anaesthesia patients). Conclusions Most time spent in hospital is wait time. A Patient Tracking System was designed to automatically display the phase in which a patient is in. It provides transparency for patients and staff in the surgical trajectory and is expected to reduce intermittent communication, improve patient flow, reduce wait times and improve patient and staff satisfaction.
Medical Engineering & Physics | 2015
H. C. M. Clogenson; A. Simonetto; J. J. van den Dobbelsteen
Over the years, the design of the tip of available catheters and guidewires has evolved into various shapes whose geometry is mostly based on common sense and experimentation. However, while the tip shape of conventional instruments can be easily modified and tested, the length of the tip of a deflectable guidewire cannot. Hence, other approaches are necessary in order to determine the proper dimensions of original instruments. In this paper, we formulate the length of the different parts of the deflectable tip of a guidewire as an optimization problem with the objective to obtain a design that is suitable for cannulating several target bifurcations of the peripheral vasculature. A direct relationship between the design of the deflectable tip and the geometry of the target bifurcations was found and the optimal dimension of the tip of the instrument was computed. Following the length specifications defined by the optimization, a new prototype was assembled, and evaluated. The deflectable guidewire could successfully cannulate most of the pre-selected branches except those bifurcations with an angle α>70°. The latter limitation could be ascribed to the mechanical properties of the instrument.
Medical Imaging 2018: Image-Guided Procedures, Robotic Interventions, and Modeling | 2018
N. J. van de Berg; Juan A. Sánchez-Margallo; Thomas Langø; J. J. van den Dobbelsteen; Baowei Fei; Robert J. Webster
Radio frequency ablation is commonly used in the treatment of hepatocellular carcinoma. Clinicians rely on imaging techniques, such as medical ultrasound, to confirm an accurate needle placement. This accuracy may improve by means of active needle steering techniques, which are currently in development. Needle steering will likely increase the clinician’s reliance on imaging techniques. This has motivated the study of the echogenicity of steerable needle joint structures. Two needles were manufactured with arrays of kerfs, similar to the compliant joint structures found in steerable needles. The needle visibility was compared to a smooth surface needle and a commercially available RFA needle. The visibility was quantified for both the shaft and tip, by means of a contrastto- noise ratio (CNR). CNR data were obtained for three insertion angles. The results show that the CNRs of the compliant joint structures were consistently higher than those of the smooth surface needle, whereas they were either higher than or comparable to those of the RFA needle. For acute insertion angles, the bevel tip of the RFA needle had a higher CNR than the conical tip of the kerfed needles, motivating the extension of this visibility study to the full needle design.