Abstrakt Technologie Srpen 2009

“A survey of snake-inspired robot designs.”

Hopkins, J. K., B. W. Spranklin, et al. (2009).

Bioinspiration and Biomimetics 4(2).


Body undulation used by snakes and the physical architecture of a snake body may offer significant benefits over typical legged or wheeled locomotion designs in certain types of scenarios. A large number of research groups have developed snake-inspired robots to exploit these benefits. The purpose of this review is to report different types of snake-inspired robot designs and categorize them based on their main characteristics. For each category, we discuss their relative advantages and disadvantages. This review will assist in familiarizing a newcomer to the field with the existing designs and their distinguishing features. We hope that by studying existing robots, future designers will be able to create new designs by adopting features from successful robots. The review also summarizes the design challenges associated with the further advancement of the field and deploying snake-inspired robots in practice. © 2009 IOP Publishing Ltd.




“A modular planar robotic manipulandum with end-point torque control.”

Howard, I. S., J. N. Ingram, et al. (2009).

J Neurosci Methods 181(2): 199-211.


Robotic manipulanda are extensively used in investigation of the motor control of human arm movements. They permit the application of translational forces to the arm based on its state and can be used to probe issues ranging from mechanisms of neural control to biomechanics. However, most current designs are optimized for studying either motor learning or stiffness. Even fewer include end-point torque control which is important for the simulation of objects and the study of tool use. Here we describe a modular, general purpose, two-dimensional planar manipulandum (vBOT) primarily optimized for dynamic learning paradigms. It employs a carbon fibre arm arranged as a parallelogram which is driven by motors via timing pulleys. The design minimizes the intrinsic dynamics of the manipulandum without active compensation. A novel variant of the design (WristBOT) can apply torques at the handle using an add-on cable drive mechanism. In a second variant (StiffBOT) a more rigid arm can be substituted and zero backlash belts can be used, making the StiffBOT more suitable for the study of stiffness. The three variants can be used with custom built display rigs, mounting, and air tables. We investigated the performance of the vBOT and its variants in terms of effective end-point mass, viscosity and stiffness. Finally we present an object manipulation task using the WristBOT. This demonstrates that subjects can perceive the orientation of the principal axis of an object based on haptic feedback arising from its rotational dynamics.




“A sub-millimetric, 0.25 mN resolution fully integrated fiber-optic force-sensing tool for retinal microsurgery.”

Iordachita, I., Z. Sun, et al. (2009).

International Journal of Computer Assisted Radiology and Surgery 4(4): 383-390.


Purpose: Retinal microsurgery requires extremely delicate manipulation of retinal tissue where tool-to-tissue interaction forces are usually below the threshold of human perception. Creating a force-sensing surgical instrument that measures the forces directly at the tool tip poses great challenges due to the interactions between the tool shaft and the sclerotomy opening. Methods: We present the design and analysisof a force measurement device that senses distal forces interior to the sclera using 1-cm long, 160 μm diameter Fiber Bragg Grating (FBG) strain sensors embedded in a 0.5 mm diameter tool shaft. Additionally, we provide an algorithm developed to cancel the influence of environmental temperature fluctuations. Results: The force-sensing prototype measures forces witha resolution of 0.25 mN in 2 DOF while being insensitive to temperature. Conclusion: Sub-millinewton resolution force sensors integrated into microsurgical instruments are feasible and have potential applications in both robotic and freehand microsurgery. © CARS 2009.




“From medical images to minimally invasive intervention: Computer assistance for robotic surgery.”

Lee, S. L., M. Lerotic, et al. (2009).

Comput Med Imaging Graph.


Minimally invasive surgery has been established as an important way forward in surgery for reducing patient trauma and hospitalization with improved prognosis. The introduction of robotic assistance enhances the manual dexterity and accuracy of instrument manipulation. Further development of the field in using pre- and intra-operative imaging guidance requires the integration of the general anatomy of the patient with clear pathologic indications and geometrical information for preoperative planning and intra-operative manipulation. It also requires effective visualization and the recreation of haptic and tactile sensing with dynamic active constraints to improve consistency and safety of the surgical procedures. This paper describes key technical considerations of tissue deformation tracking, 3D reconstruction, subject-specific modeling, image guidance and augmented reality for robotic assisted minimally invasive surgery. It highlights the importance of adapting preoperative surgical planning according to intra-operative data and illustrates how dynamic information such as tissue deformation can be incorporated into the surgical navigation framework. Some of the recent trends are discussed in terms of instrument design and the usage of dynamic active constraints and human-robot perceptual docking for robotic assisted minimally invasive surgery.




“The HD-panoramic visualization system: A new visualization system for ENT surgery.”

Strauß, G., N. Bahrami, et al. (2009).

European Archives of Oto-Rhino-Laryngology 266(9): 1475-1487.


This work examines the application possibilities of a new visualization system, the Panoramic Visualization System (HD-PVS), in ENT surgery. The Panoramic Visualization System (PVS) is a novel optical system that is neither an endoscope nor a microscope. It has a focal length of 200 mm, a wide field of view and is used together with an HD camera and an HD monitor (HD-PVS). The analysis of the visualization quality took place in laboratory conditions using 4 close-to-surgery scenarios with altogether 40 data points. Further, the system was used on patients in 45 procedures (tympanoplasty, parotidectomy, neck dissection, septumplasty, transfacial approaches). The results were analyzed following the ICCAS workflow-scheme and with standardized questionnaires. In the analysis of the visualization quality, the PVS exhibited the best total evaluation in the lab test in two out of four scenarios. In one of four scenarios, the PVS as well as the microscope achieved the maximum attainable score. In one out of four scenarios, the endoscope attained a better result than the PVS. The microscope was never superior to the HD-PVS in terms of image quality. In four out of five clinical applications, the PVS was evaluated as operational with slight modifications. Most development is needed in middle ear surgery applications. The remaining procedures already benefit in the system configuration examined here, and they were regularly accomplished with support of the PVS. The present study offers a good basis for introducing the PVS to ENT surgery. The advantages over the existing gold standard include lower initial costs for the optical system than for an operating microscope since the HD-video system is often already in place, smaller space requirements than a microscope, equal or at times better visualization quality than the microscope, the possibility of videoendoscopic representation of surgeries in which this was impossible before, and better ergonomic conditions. © 2008 Springer-Verlag.




“Integrated navigation and control software system for MRI-guided robotic prostate interventions.”

Tokuda, J., G. S. Fischer, et al. (2009).

Comput Med Imaging Graph.


A software system to provide intuitive navigation for MRI-guided robotic transperineal prostate therapy is presented. In the system, the robot control unit, the MRI scanner, and the open-source navigation software are connected together via Ethernet to exchange commands, coordinates, and images using an open network communication protocol, OpenIGTLink. The system has six states called “workphases” that provide the necessary synchronization of all components during each stage of the clinical workflow, and the user interface guides the operator linearly through these workphases. On top of this framework, the software provides the following features for needle guidance: interactive target planning; 3D image visualization with current needle position; treatment monitoring through real-time MR images of needle trajectories in the prostate. These features are supported by calibration of robot and image coordinates by fiducial-based registration. Performance tests show that the registration error of the system was 2.6mm within the prostate volume. Registered real-time 2D images were displayed 1.97s after the image location is specified.