2020 ◽  
Vol 6 (3) ◽  
pp. 571-574
Author(s):  
Anna Schaufler ◽  
Alfredo Illanes ◽  
Ivan Maldonado ◽  
Axel Boese ◽  
Roland Croner ◽  
...  

AbstractIn robot-assisted procedures, the surgeon controls the surgical instruments from a remote console, while visually monitoring the procedure through the endoscope. There is no haptic feedback available to the surgeon, which impedes the assessment of diseased tissue and the detection of hidden structures beneath the tissue, such as vessels. Only visual clues are available to the surgeon to control the force applied to the tissue by the instruments, which poses a risk for iatrogenic injuries. Additional information on haptic interactions of the employed instruments and the treated tissue that is provided to the surgeon during robotic surgery could compensate for this deficit. Acoustic emissions (AE) from the instrument/tissue interactions, transmitted by the instrument are a potential source of this information. AE can be recorded by audio sensors that do not have to be integrated into the instruments, but that can be modularly attached to the outside of the instruments shaft or enclosure. The location of the sensor on a robotic system is essential for the applicability of the concept in real situations. While the signal strength of the acoustic emissions decreases with distance from the point of interaction, an installation close to the patient would require sterilization measures. The aim of this work is to investigate whether it is feasible to install the audio sensor in non-sterile areas far away from the patient and still be able to receive useful AE signals. To determine whether signals can be recorded at different potential mounting locations, instrument/tissue interactions with different textures were simulated in an experimental setup. The results showed that meaningful and valuable AE can be recorded in the non-sterile area of a robotic surgical system despite the expected signal losses.


1994 ◽  
Vol 3 (4) ◽  
pp. 351-359 ◽  
Author(s):  
Masahiro Ishii ◽  
Masanori Nakata ◽  
Makoto Sato

This research aims at the realization of a networked virtual environment for the design of three-dimensional (3-D) objects. Based on an analysis of an ordinary collaborative design, we illustrate that a collaborative work space consists of a dialog space and an object space. In the dialog space, a participant interacts with partners, and in the object space with an object. The participants enter the dialog space and the object space in turn, appropriately. In addition, collaborative design of 3-D objects is carried out with multimodal interactions: visual, auditory, and haptic. A networked virtual environment must support these interactions without contradiction in either time or space. In this paper, we propose a networked virtual environment for a pair of participants to satisfy the conditions described above. To implement the networked system, we take into account the necessity of visual, auditory, and haptic interactions, the need for participants to switch between the dialog space and the object space quickly and appropriately, and human ergonomics on the functional space of hands and eyes. An experiment on hand-over task was done to investigate the effect of the networked haptic device with the proposed system. Object layout tasks, such as toy block layout, office furniture layout, city building layout, etc., can be performed by using this environment.


Author(s):  
Lianzhen Luo ◽  
Meyer Nahon

The determination of the interference geometry between two arbitrary objects is an essential problem encountered in the simulation of continuous contact dynamics and haptic interactions. In these applications, with known material properties, the interbody contact force is only a function of the interference geometry between two objects. Here a theoretical basis and algorithms for the calculation of the interference geometry, such as overlap region, contact area and normal, and interference volume, are presented. Two methods to obtain the contact area and normal are analyzed: an area-weighted method and a best-fitting method. The geometric properties of the area-weighted method are presented and the degenerate cases related to both methods are discussed. Methods to calculate the application point of an interbody contact force are discussed. Some numerical simulation results are presented based on the implementation of the geometric algorithms, which are verified by comparison with hand calculation. The continuity of contact normal and its application point are demonstrated for a case in which the contacting objects smoothly move with respect to each other in the simulation.


PLoS ONE ◽  
2016 ◽  
Vol 11 (6) ◽  
pp. e0157681 ◽  
Author(s):  
Min Li ◽  
Sina Sareh ◽  
Guanghua Xu ◽  
Maisarah Binti Ridzuan ◽  
Shan Luo ◽  
...  

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