Robotic-assisted versus manual Uro Dyna-CT-guided puncture in an ex-vivo kidney phantom

INTRODUCTION AND OBJECTIVES

Challenging percutaneous renal punctures to gain access to the kidney requiring guidance by cross-sectional imaging. To test the feasibility of robotic-assisted CT-guided punctures (RP) and compare them with manual laser-guided punctures (MP) with Uro Dyna-CT (Siemens Healthcare Solutions, Erlangen, Germany).

MATERIAL AND METHODS

The silicon kidney phantom contained target lesions of three sizes. RP were performed using a robotic assistance system (guidoo, BEC GmbH, Pfullingen, Germany) with a robotic arm (LBR med R800, KUKA AG, Augsburg, Germany) and a navigation software with a cone-beam-CT Artis zeego (Siemens Healthcare GmbH, Erlangen, Germany). MP were performed using the syngo iGuide Uro-Dyna Artis Zee Ceiling CT (Siemens Healthcare Solutions). Three urologists with varying experience performed 20 punctures each. Success rate, puncture accuracy, puncture planning time (PPT), and needle placement time (NPT) were measured and compared with ANOVA and Chi-Square Test.

RESULTS

One hundred eighteen punctures with a success rate of 100% for RP and 78% for MP were included. Puncture accuracy was significantly higher for RP. PPT (RP: 238 ± 90s, MP: 104 ± 21s) and NPT (RP: 128 ± 40s, MP: 81 ± 18s) were significantly longer for RP. The outcome variables did not differ significantly with regard to levels of investigators' experience.

CONCLUSION

The accuracy of RP was superior to that of MP. This study paves the way for first in-human application of this robotic puncture system.

Stress-Induced Sensitization of Insula Activation Predicts Alcohol Craving and Alcohol Use in Alcohol Use Disorder

BACKGROUND

Stress and alcohol cues trigger alcohol consumption and relapse in alcohol use disorder. However, the neurobiological processes underlying their interaction are not well understood. Thus, we conducted a randomized, controlled neuroimaging study to investigate the effects of psychosocial stress on neural cue reactivity and addictive behaviors.

METHODS

Neural alcohol cue reactivity was assessed in 91 individuals with alcohol use disorder using a validated functional magnetic resonance imaging (fMRI) task. Activation patterns were measured twice, at baseline and during a second fMRI session, prior to which participants were assigned to psychosocial stress (experimental condition) or a matched control condition or physical exercise (control conditions). Together with fMRI data, alcohol craving and cortisol levels were assessed, and alcohol use data were collected during a 12-month follow-up. Analyses tested the effects of psychosocial stress on neural cue reactivity and associations with cortisol levels, craving, and alcohol use.

RESULTS

Compared with both control conditions, psychosocial stress elicited higher alcohol cue-induced activation in the left anterior insula (familywise error-corrected p < .05) and a stress- and cue-specific dynamic increase in insula activation over time (F22,968 = 2.143, p = .007), which was predicted by higher cortisol levels during the experimental intervention (r = 0.310, false discovery rate-corrected p = .016). Cue-induced insula activation was positively correlated with alcohol craving during fMRI (r = 0.262, false discovery rate-corrected p = .032) and alcohol use during follow-up (r = 0.218, false discovery rate-corrected p = .046).

CONCLUSIONS

Results indicate a stress-induced sensitization of cue-induced activation in the left insula as a neurobiological correlate of the effects of psychosocial stress on alcohol craving and alcohol use in alcohol use disorder, which likely reflects changes in salience attribution and goal-directed behavior.

[Development and evaluation of ultrasound navigation for free-hand biopsies of small masses in the head and neck area]

BACKGROUND

Ultrasound is an important imaging method in the head and neck area. It is readily available, dynamic, inexpensive, and does not involve radiation exposure. Interventions in the complex head and neck anatomy require good orientation, which is supported by navigation systems.

OBJECTIVE

This work aimed to develop a new ultrasound-controlled navigation system for taking biopsies of small target structures in the head and neck region.

METHODS

A neck phantom with sonographically detectable masses (size: 8-10 mm) was constructed. These were automatically segmented using a ResNet-50-based deep neural network. The ultrasound scanner was equipped with an individually manufactured tracking tool.

RESULTS

The positions of the ultrasound device, the masses, and a puncture needle were recorded in the world coordinate system. In 8 out of 10 cases, an 8‑mm mass was hit. In a special evaluation phantom, the average deviation was calculated to be 2.5 mm. The tracked biopsy needle is aligned and navigated to the masses by auditory feedback.

CONCLUSION

Outstanding advantages compared to conventional navigation systems include renunciation of preoperative tomographic imaging, automatic three-dimensional real-time registration that considers intraoperative tissue displacements, maintenance of the surgeon's optical axis at the surgical site without having to look at a navigation monitor, and working freely with both hands without holding the ultrasound scanner during biopsy taking. The described functional model can also be used in open head and neck surgery.

A semi-automated robotic system for percutaneous interventions

PURPOSE

A robotic assistive device is developed for needle-based percutaneous interventions. The aim is a hybrid system using both manual and actuated robotic operation in order to obtain a device that has a large workspace but can still fit in the gantry opening of a CT scanner. This will enable physicians to perform precise and time-efficient CT-guided percutaneous interventions. The concept of the mechanics and software of the device is presented in this work.

METHODS

The approach is a semi-automated robotic assistive device, which combines manual and robotic positioning to reduce the number and size of necessary motors. The system consists of a manual rough positioning unit, a robotic fine positioning unit and an optical needle tracking unit. The resulting system has eight degrees of freedom, of which four are manual, which comprise encoders to monitor the position of each axis. The remaining four axes are actuated axes for fine positioning of the needle. Cameras are attached to the mechanical structure for 3D tracking of the needle pose. The software is based on open-source software, mainly ROS2 as robotic middleware, Moveit2 for trajectory calculation and 3D Slicer for needle path planning.

RESULTS

The communication between the components was successfully tested with a clinical CT scanner. In a first experiment, four needle insertions were planned and the deviation of the actual needle path from the planned path was measured. The mean deviation from the needle path to the target point was 21.9 mm, which is mainly caused both by translational deviation (15.4 mm) and angular deviation (6.8°) of the needle holder. The optical tracking system was able to detect the needle position with a mean deviation of 3.9 mm.

CONCLUSION

The first validation of the system was successful which proves that the proposed concept for both the hardware and software is feasible. In a next step, an automatic position correction based on the optical tracking system will be integrated, which is expected to significantly improve the system accuracy.

Learning Needle Placement in Soft Tissue With Robot-assisted Navigation

BACKGROUND/AIM

The aim of this phantom study was to evaluate the learning curves of novices practicing how to place a cone-beam computed tomography (CBCT)-guided needle using a novel robotic assistance system (RAS).

MATERIALS AND METHODS

Ten participants performed 18 punctures each with random trajectories in a phantom setting, supported by a RAS over 3 days. Precision, duration of the total intervention, duration of the needle placement, autonomy, and confidence of the participants were measured, displaying possible learning curves.

RESULTS

No statistically significant differences were observed in terms of needle tip deviation during the trial days (mean deviation day 1: 2.82 mm; day 3: 3.07 mm; p=0.7056). During the trial days, the duration of the total intervention (mean duration: day 1: 11:22 min; day 3: 07:39 min; p<0.0001) and the duration of the needle placement decreased (mean duration: day 1: 03:17 min; day 3: 02:11 min; p<0.0001). In addition, autonomy (mean percentage of achievable points: day 1: 94%; day 3: 99%; p<0.0001) and confidence of the participants (mean percentage of achievable points: day 1: 78%; day 3: 91%; p<0.0001) increased significantly during the trial days.

CONCLUSION

The participants were already able to carry out the intervention precisely using the RAS on the first day of the trial. Throughout the trial, the participants' performance improved in terms of duration and confidence.

Optimized Intraoperative Imaging for Stereotactic Planning with a Multiaxial Robotic C-arm System: Technical Note and Case Series

BACKGROUND

 The preoperative preparation of the planning dataset for frame-based stereotactic brain biopsy is often associated with logistical effort and burden on the patient. Intraoperative imaging modalities need to be investigated to overcome these limitations.

OBJECTIVE

 The objective of the study was to develop and apply a new method for the intraoperative acquisition of the planning dataset with the multiaxial robotic C-arm system Artis zeego.

METHODS

 An indication-customized dose-reduced protocol for Artis zeego was developed and implemented into the workflow. A sample of 14 patients who had undergone intraoperative imaging with Artis zeego was analyzed. A sample of 10 patients with conventional preoperative imaging by cranial computed tomography (CT) was used as a control group. Outcomes were compared with regard to target deviation, diagnostic value of the biopsies, complications, and procedure time.

RESULTS

 In all patients, a suitable intraoperative planning dataset could be acquired with Artis zeego. Total procedure time was shorter for the Artis zeego group (p = 0.01), whereas time in the operating room area was longer in the Artis zeego group (p = 0.04). Biopsy results were diagnostic in 12 patients (86%) in the Artis zeego group and in 8 patients (80%) in the control group. There were no significant differences in target size, trajectory length, or target deviation.

CONCLUSION

 Intraoperative imaging for frame-based stereotactic brain biopsy with Artis zeego is an easy and feasible method. Accuracy is comparable to conventional CT, whereas radiation exposure could be additionally reduced. It allows a significant reduction of the total procedure length and improves the comfort for the patient and staff.

Towards a companion system for collision avoidance during robot-assisted needle placement

Robotic assistance systems for surgery enable fast and precise interventions with reduced complication rates. However, these benefits are accompanied by a more complex operating room (OR) and the risk of collision with robotic assistance systems. Current strategies for collision avoidance and minimizing possible injuries require the adaptation of robotic trajectories and a computational model of the surroundings. In contrast, this work presents a novel companion system for collision avoidance without influencing robotic trajectories. The companion system consists of a preoperative planning application and an augmented reality application for intraoperative support. The companion system visualizes the workflow within the OR and allows robot movements to be seen virtually, before they are executed by the actual robotic assistance system. Preliminary experiments with users imply that the companion system leads to a positive user experience, enables users to follow a predefined workflow in the OR, but requires further refinement to improve accuracy for practical collision avoidance.

Autonomous guidewire navigation in a two dimensional vascular phantom

The treatment of cerebro- and cardiovascular diseases requires complex and challenging navigation of a catheter. Previous attempts to automate catheter navigation lack the ability to be generalizable. Methods of Deep Reinforcement Learning show promising results and may be the key to automate catheter navigation through the tortuous vascular tree. This work investigates Deep Reinforcement Learning for guidewire manipulation in a complex and rigid vascular model in 2D. The neural network trained by Deep Deterministic Policy Gradients with Hindsight Experience Replay performs well on the low-level control task, however the high-level control of the path planning must be improved further.

Addiction Research Consortium: Losing and regaining control over drug intake (ReCoDe)-From trajectories to mechanisms and interventions

One of the major risk factors for global death and disability is alcohol, tobacco, and illicit drug use. While there is increasing knowledge with respect to individual factors promoting the initiation and maintenance of substance use disorders (SUDs), disease trajectories involved in losing and regaining control over drug intake (ReCoDe) are still not well described. Our newly formed German Collaborative Research Centre (CRC) on ReCoDe has an interdisciplinary approach funded by the German Research Foundation (DFG) with a 12-year perspective. The main goals of our research consortium are (i) to identify triggers and modifying factors that longitudinally modulate the trajectories of losing and regaining control over drug consumption in real life, (ii) to study underlying behavioral, cognitive, and neurobiological mechanisms, and (iii) to implicate mechanism-based interventions. These goals will be achieved by: (i) using mobile health (m-health) tools to longitudinally monitor the effects of triggers (drug cues, stressors, and priming doses) and modify factors (eg, age, gender, physical activity, and cognitive control) on drug consumption patterns in real-life conditions and in animal models of addiction; (ii) the identification and computational modeling of key mechanisms mediating the effects of such triggers and modifying factors on goal-directed, habitual, and compulsive aspects of behavior from human studies and animal models; and (iii) developing and testing interventions that specifically target the underlying mechanisms for regaining control over drug intake.

System and path planning algorithm for low-kV X-ray free-form surface irradiation

OBJECTIVE

Intraoperative radiotherapy (IORT) after surgical resection using a low-kV-X-ray source is a proven method used in cancer treatment. However, the shape and size of the targeted surface area are limited to the size of the available applicators. This can lead to nonconformal and therefore suboptimal treatment for many patients.

METHODS

A system is proposed comprising an X-ray source with an applicator for surface irradiation mounted on a robotic arm. This is controlled by an algorithm designed for planning the required continuous path, enabling irradiation of any desired shape with a controlled dose distribution.

RESULTS

The system is shown to be capable of irradiating areas composed of rectangles on a flat surface with a homogeneity index of less than 7% inside the targeted area.

CONCLUSION

The presented results demonstrate the potential of the proposed setup to eliminate the current limitations, leading to better treatment of patients.

Towards a Treatment of Stress Urinary Incontinence: Application of Mesenchymal Stromal Cells for Regeneration of the Sphincter Muscle

Stress urinary incontinence is a significant social, medical, and economic problem. It is caused, at least in part, by degeneration of the sphincter muscle controlling the tightness of the urinary bladder. This muscular degeneration is characterized by a loss of muscle cells and a surplus of a fibrous connective tissue. In Western countries approximately 15% of all females and 10% of males are affected. The incidence is significantly higher among senior citizens, and more than 25% of the elderly suffer from incontinence. When other therapies, such as physical exercise, pharmacological intervention, or electrophysiological stimulation of the sphincter fail to improve the patient’s conditions, a cell-based therapy may improve the function of the sphincter muscle. Here, we briefly summarize current knowledge on stem cells suitable for therapy of urinary incontinence: mesenchymal stromal cells, urine-derived stem cells, and muscle-derived satellite cells. In addition, we report on ways to improve techniques for surgical navigation, injection of cells in the sphincter muscle, sensors for evaluation of post-treatment therapeutic outcome, and perspectives derived from recent pre-clinical studies.

Development of a wireless hybrid navigation system for laparoscopic surgery

Navigation devices have been essential components for Image-Guided Surgeries (IGS) including laparoscopic surgery. We propose a wireless hybrid navigation device that integrates miniature inertial sensors and electromagnetic sensing units, for tracking instruments both inside and outside the human-body. The proposed system is free of the constraints of line-of-sight or entangling sensor wires. The main functional (sensor) part of the hybrid tracker is only about 15 mm by 15 mm. We identify the sensor models and develop sensor fusion algorithms for the proposed system to get optimal estimation of position and orientation (pose). The proof-of-concept experimental results show that the proposed hardware and software system can meet the defined tracking requirements, in terms of tracking accuracy, latency and robustness to environmental interferences.

Automated Registration of Partially Defective Surfaces by Local Landmark Identification

OBJECTIVE

In computer- and robot-assisted surgery, the term "registration" refers to the definition of the geometrical relationship between the coordinate system of a surgical planning system and that of the patient. Within the context of the development of a navigation and control system for computer- and robot-assisted surgery of the lateral skull base, it was desirable to realize an algorithm for automated registration of partially defective surfaces that is reliable and suitable for use in clinical practice.

MATERIALS AND METHODS

A registration algorithm based on the use of local fingerprints for specific points on a surface (so-called "spin images") was developed. Anatomical patient landmarks were identified automatically and assigned to CT data, performing a cross-correlation analysis and an investigation of the geometrical consistency. The algorithm was evaluated within the development of the navigation and robotic control system in a laboratory setting.

RESULTS

Under laboratory conditions it could be shown that partially defective surfaces (simulated by, for example, adding white noise, or reducing or smoothing the polygon data) were correctly recognized and thereby registered. In particular, the algorithm proved its excellence in interpreting partially modified topologies.

CONCLUSIONS

The proposed procedure can be used to accomplish dynamic intra-operative registration of the skull bone by the generation of point relations to the CT images.

A technical challenge for robot-assisted minimally invasive surgery: precision surgery on soft tissue

In minimally invasive surgery, a higher degree of accuracy is required by surgeons both for current and for future applications. This could be achieved using either a manipulator or a robot which would undertake selected tasks during surgery. However, a manually-controlled manipulator cannot fully exploit the maximum accuracy and feasibility of three-dimensional motion sequences. Therefore, apart from being used to perform simple positioning tasks, manipulators will probably be replaced by robot systems more and more in the future. However, in order to use a robot, accurate, up-to-date and extensive data is required which cannot yet be acquired by typical sensors such as CT, MRI, US or common x-ray machines. This paper deals with a new sensor and a concept for its application in robot-assisted minimally invasive surgery on soft tissue which could be a solution for data acquisition in future.

Laserbasierte Qualitätssicherung für die robotergestützte Fräsabtragung an der Schädelbasis

BACKGROUND

Implanting active hearing devices in the lateral base of the skull requires high-precision, secure fixation of the electromagnetic transducer and long-life anchorage using osteosynthetic fixation plates referred to as mountain brackets. Nonlinear distortion in the acoustic signal path and consecutive implant loosening can only be avoided by exact osseous milling to create the necessary cavity bed while avoiding excessive milling. Robot technology is ideal for high-precision milling. However, safety measures are necessary in order to prevent errors from occurring during the reduction process. Ideally, a robot should be guided by a navigation system. However, robotic systems so far available do not yet have an integrated global navigation system.

MATERIALS AND METHODS

We used an animal model under laboratory conditions to examine the extent to which the semiautomatic ROBIN assistant system developed could be expected to increase osseous milling accuracy before implanting active electronic hearing devices into the recipient tissue in the cranium. An existing prototype system for robot-assisted skull base surgery was equipped with laser sensors for geometric measurement of the operation site. The three-dimensional measurement data was compared with CT simulation data before, during, and after the robot-assisted operation. The experiments were conducted on test objects as well as on animal models.

RESULTS

Under ideal conditions, the operation site could be measured at a spatial resolution of better than 0.02 mm in each dimension. However, reflections and impurities in the operation site from bleeding and rinsing fluids did have a considerable effect on data collection, necessitating specialised registering procedures. Using an error-tolerant procedure specifically developed, the effective registering error could be kept under 0.3 mm. After milling, the resulting shape matched the intended form at an accuracy level of 0.8 mm.

CONCLUSION

The results show that robot systems can reach the accuracy required for reliable microsurgery on the cranial base. High-resolution laser-based geometric measurement of the operation site enables head registration without additional artificial landmarks. During the navigated operation, the procedure can be used to ensure that the resulting cavity matches the intended shape as determined in the preoperative planning phase. This will enable quantitative analysis of, and improvement in the quality of robot-assisted surgery in the future.

[Robotics. A new dimension in otorhinolaryngology?]

Robots have entered into many aspects of human life, including operative medicine. However, current medical robots have nothing in common with anthropomorphic robots as known in science fiction novels. We distinguish manipulators, working on a master-slave principle, from robots. Robots can be defined as "automatically controlled multitask manipulators, which are freely programmable in three or more axes." The success of robots is based on their precision, lack of fatigue, and speed of action. Potential fields of application for manipulators lie in endonasal surgery and for robots in lateral skull base surgery, including mastoidectomy and drilling a cavity for implantable hearing systems and cochlear implants. We performed a number of experiments at the department of anatomy with respect to robotic lateral skull base surgery. This paper reviews the current use of manipulators and robots in operative medicine and their potential applications in otorhinolaryngology.

[Applications for a robot in the lateral skull base. Evaluation of robot-assisted mastoidectomy in an anatomic specimen]

In the past decade, a great variety of robot systems have been applied in numerous areas of life. In the public health system, robots are increasingly used in the operating theater. The potential for reproducibility and predictability was one of the main arguments for the use of robots in orthopedic treatment of bones, especially the implantation of a cementless total hip replacement. In otorhinolaryngological surgery (ENT), different hearing aids were developed: the cochlea implant for the deaf or the totally implantable hearing aid for the hearing impaired. Their site of implantation is localized in the lateral skull base. Removal of the bone mass with the reamer requires both great precision and considerable physical effort on the part of the surgeon, which does not result in an ergonomic operating technique. The following project describes the evaluation of processing parameters for a robot-assisted mastoidectomy to expose an implantation bed. The goal was to establish different parameters for robot-controlled reaming in the calotte or mastoid. In addition, several parameters were tested for their influence on surface structure, procedure reliability, and quality as well as the ability of the Mayfield clip to stabilize the head during the operation.

Robot-assisted surgery system with kinesthetic feedback

The better understanding of the systems of the human body and their specific functions has led to minimally invasive and microsurgical procedures being carried out on an ever smaller scale. New therapies will require precision of 10 microm or better, which will only be achievable with robotic teleoperators. Experience with existing robot-assisted surgery systems shows that the human-machine interface is a critical component for acceptance of this technology, but no universally satisfactory interface has yet been found. Therefore, this article investigates a new concept based on kinesthetic motion feedback and presents details of the implementation of a first prototype.

A voice-controlled robotic assistant for neuroendoscopy

This paper describes experiments with a voice-controlled robot system to be used in endoscopic neurosurgery. The robot was a modified version of the robot described in previous publications of the group at Fraunhofer IPA and HSK. To control the robot a voice-controlled user interface was developed. The experiments were conducted on cadavers for three standard approaches in neuroendoscopy. The goal was to gain experience with a voice-controlled user interface and also with the set-up and use of the robotic system under clinical conditions. The results indicate that modifications to the robot and user interface are necessary. However the overall feasibility of the application was demonstrated.

Motion feedback as a navigation aid in robot assisted neurosurgery

This paper describes a test prototype for precision robot-assisted surgery using a hexapod operating robot and a movable operating cockpit. The objective of the work described is twofold: 1) To evaluate the use of hexapod robots for precisely manipulating endoscopes and surgical instruments in sub-millimeter surgery. 2) To test a new user interface concept based on motion feedback. This paper gives an overview of the system components and the user interface concept, and reports results from initial tests. Finally, the paper investigates potential applications and areas for further development.

UltraTrainer--a training system for medical ultrasound examination

This paper introduces the prototype of the computer program UltraTrainer, which could simplify the education and training of physicians working with medical ultrasound systems. The UltraTrainer replaces probe and patient by a magnetical tracking system and 3D-data from a real examination, which are registered with a phantom. In this way the UltraTrainer makes a simulation of the real ultrasound examination possible, which can be useful for students and physicians. This paper describes the system components and gives an overview of potential applications.