RESUMO
Free-hand computed tomography (CT)-guided interventions are common in interventional radiology. Their accuracy and technical success are highly dependent on the skill and experience of the performing interventionalist. This study evaluates a new, patient-mounted navigation device, which aims to facilitate percutaneous interventions-the Access Cube (AC). Sixty punctures were performed on 2 phantoms (rigid vs nonrigid) comparing the Free-Hand Method (FHM) to the AC on measures of accuracy, time, and the need for intraprocedural scans. Using the AC, punctures were significantly more accurate (3.8 mm ± 1.3 mm vs FHM 6.7 mm ± 4.5 mm, P = .004), significantly faster (263.1 s ± 84.4 s vs FHM 411.2 s ± 141.0 s, P < .001) and needed significantly fewer intraprocedural scans (1.4 ± 0.6 vs FHM 2.8 ± 0.4, P < .001). The AC may enable interventionalists to perform faster and more accurate punctures in a clinical setting.
RESUMO
Humanoid robots (i.e., robots with a human-like body) are projected to be mass marketed in the future in several fields of application. Today, however, user evaluations of humanoid robots are often based on mediated depictions rather than actual observations or interactions with a robot, which holds true not least for scientific user studies. People can be confronted with robots in various modes of presentation, among them (1) 2D videos, (2) 3D, i.e., stereoscopic videos, (3) immersive Virtual Reality (VR), or (4) live on site. A systematic investigation into how such differential modes of presentation influence user perceptions of a robot is still lacking. Thus, the current study systematically compares the effects of different presentation modes with varying immersive potential on user evaluations of a humanoid service robot. Participants (N = 120) observed an interaction between a humanoid service robot and an actor either on 2D or 3D video, via a virtual reality headset (VR) or live. We found support for the expected effect of the presentation mode on perceived immediacy. Effects regarding the degree of human likeness that was attributed to the robot were mixed. The presentation mode had no influence on evaluations in terms of eeriness, likability, and purchase intentions. Implications for empirical research on humanoid robots and practice are discussed.
RESUMO
PURPOSE: To describe the features of a novel patient-mounted system for CT-guided needle navigation, the Puncture Cube System (PCS), and to evaluate the accuracy and efficiency of the PCS by (a) applying numerical simulations and (b) by conducting punctures using the system in comparison to punctures using the free-hand method (FHM). METHODS: The PCS consists of a self-adhesive cube that is attached to the patient, with multiple through-holes in the upper and lower template plate and dedicated software that, using a computer vision algorithm, recognizes the cube in a planning scan. The target in the image dataset is connected by a line, here "virtual needle," which passes through the cube. For any chosen path of the virtual needle, the entry points for the needle into the cube are displayed by the software for the upper and lower template on-the-fly. The possible exactness of the system was investigated by using numerical simulations. Next, 72 punctures were performed by 6 interventionists using a phantom to compare for accuracy, time requirement, and number of CT scans for punctures with the system to the FHM ex vivo (phantom study). RESULTS: The theoretical precision to arrive at targets increased with the distance of the target but remained low. The mean error for targets up to 20 cm below the lower plate was computed to be well below 0.5 mm, and the worst-case error stayed below 1.3 mm. Compared to a conventional free-hand procedure, the use of the navigation system resulted in a statistically significantly improved accuracy (3.4 mm ± 2.3 mm versus FHM 4.9 mm ± 3.2 mm) and overall lower intervention time (168 s ± 28.5 s versus FHM 200 s ± 44.8 s). Furthermore, the number of CT scans was reduced to 2.3 versus FHM 2.8). CONCLUSION: The PCS is a promising technique to improve accuracy and reduce intervention time in CT-guided needle navigations compared to the FHM.
