Toward the improvement of image-guided interventions for minimally invasive surgery: three factors that affect performance

Constrained stochastic state estimation of deformable 1D objects: Application to single-view 3D reconstruction of catheters with radio-opaque markers

Minimally invasive fluoroscopy-based procedures are the gold standard for diagnosis and treatment of various pathologies of the cardiovascular system. This kind of procedures imply for the clinicians to infer the 3D shape of the device from 2D images, which is known to be an ill-posed problem. In this paper we present a method to reconstruct the 3D shape of the interventional device, with the aim of improving the navigation. The method combines a physics-based simulation with non-linear Bayesian filter. Whereas the physics-based model provides a prediction of the shape of the device navigating within the blood vessels (taking into account non-linear interactions between the catheter and the surrounding anatomy), an Unscented Kalman Filter is used to correct the navigation model using 2D image features as external observations. The proposed framework has been evaluated on both synthetic and real data, under different model parameterizations, filter parameters tuning and external observations data-sets. Comparing the reconstructed 3D shape with a known ground truth, for the synthetic data-set, we obtained average values for 3D Hausdorff Distance of 0.81±0.53mm, for the 3D mean distance at the segment of 0.37±0.17mm and an average 3D tip error of 0.24±0.13mm. For the real data-set,we obtained an average 3D Hausdorff distance of 1.74±0.77mm, a average 3D mean distance at the distal segment of 0.91±0.14mm, an average 3D error on the tip of 0.53±0.09mm. These results show the ability of our method to retrieve the 3D shape of the device, under a variety of filter parameterizations and challenging conditions: uncertainties on model parameterization, ambiguous views and non-linear complex phenomena such as stick and slip motions.

Spatial cognition in minimally invasive surgery: a systematic review

Background

Spatial cognition is known to play an important role in minimally invasive surgery (MIS), as it was found to enable faster surgical skill acquisition, reduce surgical time and errors made and significantly improve surgical performance. No prior research attempted to summarize the available literature, to indicate the level of importance of the individual spatial abilities and how they impact surgical performance and skill acquisition in MIS.

Methods

Psychological and medical databases were systematically searched to identify studies directly exploring spatial cognition in MIS learning and performance outcomes. Articles written in the English language articles, published between 2006 and 2016, investigating any and all aspect of spatial cognition in direct relation to influence over performance or learning of MIS, were deemed eligible.

Results

A total of 26 studies satisfied this criterion and were included in the review. The studies were very heterogeneous and the vast majority of the participants were novice trainees but with variable degree of skills. There were no clinical studies as almost all studies were conducted on either box trainers or virtual reality simulators. Mental rotation ability was found to have a clear impact on operative performance and mental practice was identified as an effective tool to enhance performance, pre-operatively. Ergonomic set-up of the MIS equipment has a marked influence on MIS performance and learning outcomes.

Conclusions

Spatial cognition was found to play an important role in MIS, with mental rotation showing a specific significance. Future research is required to further confirm and quantify these findings in the clinical settings.

Single-view X-ray depth recovery: toward a novel concept for image-guided interventions

PURPOSE

X-ray imaging is widely used for guiding minimally invasive surgeries. Despite ongoing efforts in particular toward advanced visualization incorporating mixed reality concepts, correct depth perception from X-ray imaging is still hampered due to its projective nature.

METHODS

In this paper, we introduce a new concept for predicting depth information from single-view X-ray images. Patient-specific training data for depth and corresponding X-ray attenuation information are constructed using readily available preoperative 3D image information. The corresponding depth model is learned employing a novel label-consistent dictionary learning method incorporating atlas and spatial prior constraints to allow for efficient reconstruction performance.

RESULTS

We have validated our algorithm on patient data acquired for different anatomy focus (abdomen and thorax). Of 100 image pairs per each of 6 experimental instances, 80 images have been used for training and 20 for testing. Depth estimation results have been compared to ground truth depth values.

CONCLUSION

We have achieved around [Formula: see text] and [Formula: see text] mean squared error on abdomen and thorax datasets, respectively, and visual results of our proposed method are very promising. We have therefore presented a new concept for enhancing depth perception for image-guided interventions.

Action and attentional load can influence aperture effects on motion perception

When a moving featureless contour is viewed through a stationary circular aperture that occludes the contour's endpoints and the contour moves in a direction non-parallel to its orientation, observers report the contour's direction of motion as perpendicular to the contour's orientation regardless of its actual direction. In typical studies of this aperture effect on motion perception, observers made perceptual judgments of the line's motion. The aperture effect was not measured when observers actively controlled the line's motion. In addition, effects of attentional load on the aperture effect were not measured. Here, we demonstrated that attentional load influenced the aperture effect. Active control reduced the aperture effect, but did not eliminate it. Results have theoretical implications for motion perception and practical implications for the design of technologies that limit an observer's field-of-view such as surgical cameras.

Navigation-assisted fluoroscopy in minimally invasive direct lateral interbody fusion: a cadaveric study

BACKGROUND

Minimally invasive surgery (MIS) is dependent on intraoperative fluoroscopic imaging for visualization, which significantly increases exposure to radiation. Navigation-assisted fluoroscopy (NAV) can potentially decrease radiation exposure and improve the operating room environment by reducing the need for real-time fluoroscopy. The direct lateral interbody fusion (DLIF) procedure is a technique for MIS intervertebral lumbar and thoracic interbody fusions. This study assesses the use of navigation for the DLIF procedure in comparison to standard fluoroscopy (FLUORO), as well as the accuracy of the NAV MIS DLIF procedure.

METHODS

Three fresh whole-body cadavers underwent multiple DLIF procedures at the T10-L5 levels via either NAV or FLUORO. Radiation exposure and surgical times were recorded and compared between groups. An additional cadaver was used to evaluate the accuracy of the NAV system for the DLIF procedure by measuring the deviation error as the surgeon worked further from the anterior superior iliac spine tracker.

RESULTS

Approach, discectomy, and total fluoroscopy times for FLUORO were longer than NAV (P < .05). In contrast, the setup time was longer in NAV (P = .005). Cage insertion and total operating times were similar for both. Radiation exposure to the surgeon for NAV was significantly less than FLUORO (P < .05). Accuracy of the NAV system was within 1 mm for L2-5.

CONCLUSION

Navigation for the DLIF procedure is feasible. Accuracy for this procedure over the most common levels (L2-5) is likely sufficient for safe clinical application. Although initial setup times were longer with NAV, simultaneous anteroposterior and lateral imaging with the NAV system resulted in overall surgery times similar to FLUORO. Navigation minimizes fluoroscopic radiation exposure.

CLINICAL SIGNIFICANCE

Navigation for the DLIF procedure is accurate and decreases radiation exposure without increasing the overall surgical time.

Visually Guided Haptic Search

In this study, we investigate the influence of visual feedback on haptic exploration. A haptic search task was designed in which subjects had to haptically explore a virtual display using a force-feedback device and to determine whether a target was present among distractor items. Although the target was recognizable only haptically, visual feedback of finger position or possible target positions could be given. Our results show that subjects could use visual feedback on possible target positions even in the absence of feedback on finger position. When there was no feedback on possible target locations, subjects scanned the whole display systematically. When feedback on finger position was present, subjects could make well-directed movements back to areas of interest. This was not the case without feedback on finger position, indicating that showing finger position helps to form a spatial representation of the display. In addition, we show that response time models of visual serial search do not generally apply for haptic serial search. Consequently, in teleoperation systems, for instance, it is helpful to show the position of the probe even if visual information on the scene is poor.

Expertise and Skill in Minimally Invasive Surgery

New attitudes to medical ethics and demands for efficiency have brought increased attention to surgical skills and training. It is important to characterize the expertise and skill involved in the multidimensional surgical profession. At a time of change, there is a need to discuss the nature of surgical expertise, and also the prospects for resident training, with special reference to new minimally invasive techniques (MIS).

In this paper, we selectively review knowledge on surgical expertise and the specific demands placed on a skilled MIS surgeon. In addition, the review contains a selection of studies from those areas that have been seen as important for the future of training in surgery.

Perceptual distortions produce multidimensional stress profiles in novice users of an endoscopic surgery simulator

OBJECTIVES

We determine the impact of perceptual-motor distortions on multidimensional stress dynamics in novice users of an endoscopic/laparoscopic surgery simulator during performance of a peg-transfer task.

BACKGROUND

Surgeons find the endoscopic/laparoscopic surgery procedure to be more mentally stressful than open surgery. This investigation was designed to identify specific stress dimensions associated with these procedures and to determine the contributions to that stress made by loss of depth information resulting from image-guided views of the surgical field and by disruption of eye-hand mapping. Because stress reactions might depend upon familiarity with these procedures, the study focused upon novice participants.

METHOD

An endoscopic box-simulator featured in surgical training was used in conjunction with the Dundee Stress State Questionnaire, a well-validated multidimensional stress state instrument. A control group (no perceptual distortions) viewed the simulated "surgical field" directly. Two other groups viewed the surgical field through TV images in which spatial rotation of the images was absent or in which the images were rotated 90 degrees from the actual line of sight.

RESULTS

Performance efficiency in the simulator varied inversely with the degree of perceptual-motor distortion. Reactions reflecting increased task coping were observed in all groups. These were accompanied in the image groups by negative reactions involving decreases in hedonic tone and control and confidence and an increase in tense arousal.

CONCLUSIONS

Perceptual-motor distortions are sources of complex task-induced stress profiles in novices using an endoscopic surgery simulator.

APPLICATION

Procedures to reduce stress in endoscopic/laparoscopic surgery trainees may benefit from knowledge regarding specific stress dimensions involved.

Haptics in minimally invasive surgery--a review

This article gives an overview of research performed in the field of haptic information feedback during minimally invasive surgery (MIS). Literature has been consulted from 1985 to present. The studies show that currently, haptic information feedback is rare, but promising, in MIS. Surgeons benefit from additional feedback about force information. When it comes to grasping forces and perceiving slip, little is known about the advantages additional haptic information can give to prevent tissue trauma during manipulation. Improvement of haptic perception through augmented haptic information feedback in MIS might be promising.