μRALP and Beyond: Micro-Technologies and Systems for Robot-Assisted Endoscopic Laser Microsurgery.

Laser microsurgery is the current gold standard surgical technique for the treatment of selected diseases in delicate organs such as the larynx. However, the operations require large surgical expertise and dexterity, and face significant limitations imposed by available technology, such as the requirement for direct line of sight to the surgical field, restricted access, and direct manual control of the surgical instruments. To change this status quo, the European project μRALP pioneered research towards a complete redesign of current laser microsurgery systems, focusing on the development of robotic micro-technologies to enable endoscopic operations.

Detection of Breathing Movements of Preterm Neonates by Recording Their Abdominal Movements with a Time-of-Flight Camera.

In order to deliver an aerosolized drug in a breath-triggered manner, the initiation of the patient's inspiration needs to be detected. The best-known systems monitoring breathing patterns are based on flow sensors. However, due to their large dead space volume, flow sensors are not advisable for monitoring the breathing of (preterm) neonates.

Droplet applicator module for reproducible and controlled endoscopic laryngeal adductor reflex stimulation.

This work presents a droplet applicator module to generate stable droplets with different muzzle energies for the reproducible endoscopic stimulation of the laryngeal adductor reflex (LAR). The LAR is a protective reflex of the human larynx; an abnormal LAR performance may cause aspiration pneumonia. A pathological LAR can be detected by evaluating its onset latency.

Preclinical Performance Evaluation of a Robotic Endoscope for Non-Contact Laser Surgery.

Despite great efforts, transoral robotic laser surgery has not been established clinically. Patient benefits are yet to be proven to accept shortcomings of robotic systems. In particular, laryngeal reachability and transition from microscope to accurate endoscopic laser ablation have not been achieved.

Workflow assessment as a preclinical development tool : Surgical process models of three techniques for minimally invasive cochlear implantation.

Purpose: Minimally invasive cochlear implant surgery is a challenging procedure due to high demands on accuracy. For clinical success, an according assistance system has to compete against the traditional approach in terms of risk, operating time and cost. It has not yet been determined what kind of system is the most suited.

A dataset of laryngeal endoscopic images with comparative study on convolution neural network-based semantic segmentation.

Purpose: Automated segmentation of anatomical structures in medical image analysis is a prerequisite for autonomous diagnosis as well as various computer- and robot-aided interventions. Recent methods based on deep convolutional neural networks (CNN) have outperformed former heuristic methods. However, those methods were primarily evaluated on rigid, real-world environments.

Feasibility Assessment of Optical Coherence Tomography-Guided Laser Labeling in Middle Cranial Fossa Approach.

Introduction: Different approaches have been developed to find the position of the internal auditory canal (IAC) in middle cranial fossa approach. A feasibility study was performed to investigate the combination of cone beam computed tomography (CBCT), optical coherence tomography (OCT), and laser ablation to assist a surgeon in a middle cranial fossa approach by outlining the internal auditory canal (IAC).

Materials And Methods: A combined OCT laser setup was used to outline the position of IAC on the surface of the petrous bone in cadaveric semi-heads.

High-accuracy drilling with an image guided light weight robot: autonomous versus intuitive feed control.

Purpose: Assistance of robotic systems in the operating room promises higher accuracy and, hence, demanding surgical interventions become realisable (e.g. the direct cochlear access).

Stereo vision-based tracking of soft tissue motion with application to online ablation control in laser microsurgery.

Recent research has revealed that image-based methods can enhance accuracy and safety in laser microsurgery. In this study, non-rigid tracking using surgical stereo imaging and its application to laser ablation is discussed. A recently developed motion estimation framework based on piecewise affine deformation modeling is extended by a mesh refinement step and considering texture information.

Patient specific pointer tool for corrective osteotomy: Quality of symmetry based planning and case study of ulnar reconstruction surgery.

Malunion after forearm fractures are described to appear in 2% to 10% of cases. Reconstructive surgeries ensure adequate anatomical repositioning. Their importance derives from the fact that malunion can often lead to severe pain as well as deformities causing loss of function and aesthetic issues not only in the forearm, but also the wrist and elbow joint.

Workflow and simulation of image-to-physical registration of holes inside spongy bone.

Purpose: Mastoid cells as well as trabecula provide unique bone structures, which can serve as natural landmarks for registration. Preoperative imaging enables sufficient acquisition of these structures, but registration requires an intraoperative counterpart. Since versatile surgical interventions involve drilling into mastoid cells and trabecula, we propose a registration method based on endoscopy inside of these drill holes.

Experimental Visualization of Labyrinthine Structure with Optical Coherence Tomography.

Introduction: Visualization of inner ear structures is a valuable strategy for researchers and clinicians working on hearing pathologies. Optical coherence tomography (OCT) is a high-resolution imaging technology which may be used for the visualization of tissues. In this experimental study we aimed to evaluate inner ear anatomy in well-prepared human labyrinthine bones.

Design considerations for patient-specific surgical templates for total hip arthroplasty with respect to acetabular cartilage.

Patient-specific instruments (PSIs) are clinically used to support the surgeon during a planned intervention. The planning is typically done based on volumetric image data from medical imaging systems, e.g.

Soft tissue motion tracking with application to tablet-based incision planning in laser surgery.

Purpose: Recent research has revealed that incision planning in laser surgery deploying stylus and tablet outperforms micromanipulator control. However, vision-based adaption to dynamic surgical scenes has not been addressed so far. In this study, scene motion compensation for tablet-based planning by means of tissue deformation tracking is discussed.

Configuration optimization and experimental accuracy evaluation of a bone-attached, parallel robot for skull surgery.

Purpose: Minimally invasive cochlear implantation is a novel surgical technique which requires highly accurate guidance of a drilling tool along a trajectory from the mastoid surface toward the basal turn of the cochlea. The authors propose a passive, reconfigurable, parallel robot which can be directly attached to bone anchors implanted in a patient's skull, avoiding the need for surgical tracking systems. Prior to clinical trials, methods are necessary to patient specifically optimize the configuration of the mechanism with respect to accuracy and stability.

Cochlear Dummy Electrodes for Insertion Training and Research Purposes: Fabrication, Mechanical Characterization, and Experimental Validation.

To develop skills sufficient for hearing preservation cochlear implant surgery, surgeons need to perform several electrode insertion trials in ex vivo temporal bones, thereby consuming relatively expensive electrode carriers. The objectives of this study were to evaluate the insertion characteristics of cochlear electrodes in a plastic scala tympani model and to fabricate radio opaque polymer filament dummy electrodes of equivalent mechanical properties. In addition, this study should aid the design and development of new cochlear electrodes.

Comparative study on surface reconstruction accuracy of stereo imaging devices for microsurgery.

Purpose: Processing stereoscopic image data is an emerging field. Especially in microsurgery that requires sub-millimeter accuracy, application of stereo-based methods on endoscopic and microscopic scenarios is of major interest. In this context, direct comparison of stereo-based surface reconstruction applied to several camera settings is presented.

Mechanical characterization of bone anchors used with a bone-attached, parallel robot for skull surgery.

Bone-attached robots and microstereotactic frames, intended for deep brain stimulation and minimally invasive cochlear implantation, typically attach to a patient's skull via bone anchors. A rigid and reliable link between such devices and the skull is mandatory in order to fulfill the high accuracy demands of minimally invasive procedures while maintaining patient safety. In this paper, a method is presented to experimentally characterize the mechanical properties of the anchor-bone linkage.

The "Iceberg Phenomenon": As Soon as One Technological Problem in NOTES Is Solved, the Next One Appears!

Purpose: Though already proclaimed about 7 years ago, natural orifice transluminal endoscopic surgery (NOTES) is still in its early stages. A multidisciplinary working team tried to analyze the technical obstacles and identify potential solutions.

Methods: After a comprehensive review of the literature, a group of 3 surgeons, 1 gastroenterologist, 10 engineers, and 1 representative of biomedical industry defined the most important deficiencies within the system and then compiled as well as evaluated innovative technologies that could be used to help overcome these problems.

An experimental evaluation of loads occurring during guided drilling for cochlear implantation.

Purpose: During guided drilling for minimally invasive cochlear implantation and related applications, typically forces and torques act on the employed tool guides, which result from both the surgeon's interaction and the bone drilling process. Such loads propagate through the rigid mechanisms and result in deformations of compliant parts, which in turn affect the achievable accuracy. In this paper, the order of magnitude as well as the factors influencing such loads are studied experimentally to facilitate design and optimization of future drill guide prototypes.

OpenIGTLink interface for state control and visualisation of a robot for image-guided therapy systems.

Purpose: The integration of a robot into an image-guided therapy system is still a time consuming process, due to the lack of a well-accepted standard for interdevice communication. The aim of this project is to simplify this procedure by developing an open interface based on three interface classes: state control, visualisation, and sensor. A state machine on the robot control is added to the concept because the robot has its own workflow during surgical procedures, which differs from the workflow of the surgeon.

Tissue surface information for intraoperative incision planning and focus adjustment in laser surgery.

Purpose: Introducing computational methods to laser surgery are an emerging field. Focusing on endoscopic laser interventions, a novel approach is presented to enhance intraoperative incision planning and laser focusing by means of tissue surface information obtained by stereoscopic vision.

Methods: Tissue surface is estimated with stereo-based methods using nonparametric image transforms.

Temporal bone borehole accuracy for cochlear implantation influenced by drilling strategy: an in vitro study.

Purpose: Minimally invasive cochlear implantation is a surgical technique which requires drilling a canal from the mastoid surface toward the basal turn of the cochlea. The choice of an appropriate drilling strategy is hypothesized to have significant influence on the achievable targeting accuracy. Therefore, a method is presented to analyze the contribution of the drilling process and drilling tool to the targeting error isolated from other error sources.

Towards intra-operative OCT guidance for automatic head surgery: first experimental results.

In recent years, optical coherence tomography (OCT) has gained increasing attention not only as an imaging device, but also as a guidance system for surgical interventions. In this contribution, we propose OCT as an external high-accuracy guidance system, and present an experimental setup of an OCT combined with a cutting laser. This setup enables not only in situ monitoring, but also automatic, high-accuracy, three-dimensional navigation and processing.

An automated insertion tool for cochlear implants with integrated force sensing capability.

Purpose: Minimally invasive cochlear implantation and residual hearing preservation require both the surgical approach to the cochlea as well as the implant insertion to be performed in an atraumatic fashion. Considering the geometric limitations of this approach, specialized instrumentation is required to insert the electrode while preserving intracochlear membranes carrying the sensory hair cells.

Methods: An automated insertion tool for cochlear implants, which is capable of sensing insertion forces with a theoretical resolution of 30 μN, is presented.