Gwilliam2012 inproceedings A common surgical task is identifying hard lumps embedded in soft tissue. During open procedures, surgeons can localize lumps using the distributed tactile feedback provided through manual pal- pation with the fingers. Tactile displays developed to restore tac- tile feedback for both traditional and robot-assisted minimally in- vasive surgery (RMIS) are designed generically to provide a wide range of tactile sensations to the finger, and as such, are often bulky and electro-mechanically complex. We developed a novel air-jet pneumatic lump display that directs a thin stream of pressurized air through an aperture on to the fingerpad. The display is optimized to produce the sensation of a lump to the finger, but is considerably less complex in design and hardware requirements, and is designed with two degrees of freedom, enabling independent control of pres- sure and aperture size. We describe the design of the display and demonstrate the process through which the output of the display can be controlled, using two different methods for controlling aperture size. The output of the pneumatic air-jet lump display is quanti- tatively measured with an array of capacitive tactile sensors and results show that the display is capable of changing both the size and pressure of the output. We plan to present a demonstration of the device at the haptics symposium. {Design and Control of an air-jet lump display.} :home/jimgwilliam/JHU/Literature Papers/2012/Gwilliam et al/Gwilliam et al.\_2012.pdf:pdf 45--49 2012 Proc. IEEE Haptics Symposium 2012 Zhou2007 inproceedings Previous studies have shown that the texture of objects can be perceived indirectly through a probe held in the hand. Those studies have suggested that the power of the vibrations transmitted through the probe to the hand play an important role in conveying the information necessary to perceive the roughness of surfaces. To further characterize the nature of roughness information in indirect touch, we examined the contribution of scanning velocity and force on texture perception via a probe. We surmised that if vibratory power is the critical aspect of the input then the perceived roughness should systematically change with changes in velocity and force. The textures were ones encountered in daily life such as corduroy, rubber, and water color paper. Human subjects made magnitude estimations of the perceived roughness of the textures that were mounted on a rotating drum and were contacted with a Delrin probe that subjects held using a pencil grip. Two conditions were tested: 1) scanning velocities of 40, 80, and 160 mm/s with a constant force of 1.5 N 2) contact forces of 0.5, 1.0, and 1.5 N with a constant velocity of 80 mm/s. We observed that a three-fold increase in force, which increased the intensity of the vibration, had little effect on the judgments of roughness. The four-fold increase in velocity, which produced changes in both vibratory intensity and frequency, resulted in a significant increase in the roughness judgments. These observations indicate that roughness is not related to vibratory power in a simple way and that other aspects of the vibrations such as the temporal structure of the vibrations may play a role in probe-mediated texture perception. Using recordings from peripheral afferents of monkeys we also explore potential neural coding mechanisms. {Neural coding of texture through hand held probes. Program No 862.6. San Diego, CA.} San Diego, CA :home/jimgwilliam/JHU/Literature Papers/2007/Zhou et al/Zhou et al.\_2007.pdf:pdf 2007 Society for Neuroscience 2007 Bianchi2011 inproceedings During manual palpation, clinicians rely on distributed tactile information to identify and localize hard lumps embedded in soft tissue. The development of tactile feedback systems to enhance palpation using robot-assisted minimally invasive surgery (RMIS) systems is challenging due to size and weight constraints, motivating a pneumatic actuation strategy. Recently, an air jet approach has been proposed for generating a lump percept. We use this technique to direct a thin stream of air through an aperture directly on the finger pad, which indents the skin in a hemispherical manner, producing a compelling lump percept. We hypothesize that the perceived parameters of the lump (e.g. size and stiffness) can be controlled by jointly adjusting air pressure and the aperture size through which air escapes. In this work, we investigate how these control variables interact to affect perceived pressure on the finger pad. First, we used a capacitive tactile sensor array to measure the effect of aperture size on output pressure, and found that peak output pressure increases with aperture size. Second, we performed a psychophysical experiment for each aperture size to determine the just noticeable difference (JND) of air pressure on the finger pad. Subject-averaged pressure JND values ranged from 19.4???24.7 kPa, with no statistical differences observed between aperture sizes. The aperture-pressure relationship and the pressure JND values will be fundamental for future display control. {Characterization of an air jet haptic lump display.} :home/jimgwilliam/JHU/Literature Papers/2011/Bianchi et al/Bianchi et al.\_2011.pdf:pdf 3467--3470 2011 Proc. IEEE Engineering in Medicine and Biology Society 2011 Gwilliam2010a inproceedings An important task in clinical diagnosis is identifying and localizing hard lumps or nodules in soft tissues. The nodules vary in size and shape, and can lie at different depths beneath the tissue surface. Detection of nodules with the bare finger requires that the nervous system be able to discriminate between the surrounding tissue and the nodule. We performed a combined psychophysical study in humans and a neurophysiological study in non-human primates (macaca mulatta) to investigate the neural mechanisms underlying lump detection in artificial soft tissue. {Neural coding of lump detection in soft tissue. Program No. 782.7/PP3. San Diego, CA.} :home/jimgwilliam/JHU/Literature Papers/2010/Gwilliam et al/Gwilliam et al.\_2010(2).pdf:pdf 2010 Society for Neuroscience 2010 Okamura2011 incollection Surgical robotics is a rapidly evolving field. With roots in academic research, surgical robotic systems are now clinically used across a wide spectrum of surgical procedures. Surgical Robotics: Systems Applications and Visions provides a comprehensive view of the field both from the research and clinical perspectives. This volume takes a look at surgical robotics from four different perspectives, addressing vision, systems, engineering development and clinical applications of these technologies. The book also: -Discusses specific surgical applications of robotics that have already been deployed in operating rooms -Covers specific engineering breakthroughs that have occurred in surgical robotics -Details surgical robotic applications in specific disciplines of surgery including orthopedics, urology, cardiac surgery, neurosurgery, ophthalmology, pediatric surgery and general surgery Surgical Robotics: Systems Applications and Visions is an ideal volume for researchers and engineers working in biomedical engineering. {Force feedback and sensory substitution for robot-assisted surgery.} Rosen, J and Hannaford, B and Satava, R M 18 biomedical engineering control mechatronics robotics surgical robotics 419--448 978-1-4419-1125-4 2011 Surgical Robotics - Systems, Applications, and Visions undefined Springer 2011 Gwilliam2008 article Nerve stimulation typically employs charge-balanced current injection with a delay between the cathodal and anodal phases. Typically these waveforms are produced using a microprocessor. However, once appropriate stimulus parameters are chosen, they tend to remain fixed within an application, making computational power unnecessary. In such cases, it would be advantageous to replace the microprocessor with integrated circuitry and hardware controls for maintaining fixed pulse parameters. We describe here an architecture that generates controllable charge-balanced pulses but requires no computer processing components. The circuitry has been engineered such that minimum size and power consumption can be achieved when fabricated into an IC chip, making it ideal for many long term, portable nerve stimulation devices and applications. Animals Electric Stimulation Electric Stimulation: instrumentation Electric Stimulation: methods Electrodes Humans Implanted Microcomputers Peripheral Nervous System Peripheral Nervous System: physiology Peripheral Nervous System: radiation effects 17950907 0165-0270 146--50 1 http://www.ncbi.nlm.nih.gov/pubmed/17950907 Journal of neuroscience methods {A charge-balanced pulse generator for nerve stimulation applications.} 168 February 2008 10.1016/j.jneumeth.2007.09.004 > 2008-02 Gwilliam2009 inproceedings Direct haptic feedback and graphical force feed- back have both been hypothesized to improve the performance of robot-assisted surgery. In this study we evaluate the benefits of haptic and graphical force feedback on surgeon perfor- mance and tissue exploration behavior during a teleoperated palpation task of artificial tissues. Seven surgeon subjects (four experienced in robot-assisted surgery) used a 7-degree-of- freedom teleoperated surgical robot to identify a comparatively rigid rigid target object (representing a calcified artery) in phantom heart models using the following feedback conditions: (1) direct haptic and graphical feedback, (2) direct haptic only, (3) graphical feedback only, and (4) no feedback. To avoid the problems of force sensing in a minimally invasive surgical environment, we use a position-exchange controller with dynamics compensation for direct haptic feedback and a force estimator displayed via tool-tip tracking bar graph for graphical force feedback. Although the transparency of the system is limited with this approach, results show that direct haptic force feedback minimizes applied forces to the tissue, while coupled haptic and graphical force feedback minimizes subject task error. For experienced surgeons, haptic force feedback substantially reduced task error independent of graphical feedback. {Effects of haptic and graphical force feedback on teleoperated palpation.} 1050-4729 :home/jimgwilliam/JHU/Literature Papers/2009/Gwilliam et al/Gwilliam et al.\_2009.pdf:pdf 677--682 2009 Proc. IEEE International Conference on Robotics and Automation IEEE 2009 Mahvash2008 inproceedings In this paper, we develop and test a 6-degree-of-freedom surgical teleoperator that has four possible modes of operation: (1) direct force feedback, (2) graphical force feedback, (3) direct and graphical force feedback together, and (4) no force feedback. In all cases, visual feedback of the: environment is provided via a head-mounted display. A position-position controller with local dynamic compensators provides the direct force feedback. The graphical force feedback is overlaid on the environment image, and displays a bar whose height and color is related to the environment force estimated using the current applied to the actuators of the patient-side arm. We evaluate the performance of the teleoperator modes in assisting a user to find the location of stiff objects hidden inside a soft material, similar to a calcified artery hidden in heart tissue and a tumor in the prostate. Seven people used the teleoperator t:o perform palpation in these materials. Results showed that direct force feedback mode minimizes palpation task error for the heart model. {Force-feedback surgical teleoperator: controller design and palpation experiments.} Lump Detection biological tissues cardiology compensation environment color image force feedback force-feedback 6-DOF surgical teleoperator graphical force feedback head-mounted display heart tissue helmet mounted displays local dynamic compensator medical robotics palpation experiment patient-side arm position control position-position controller surgery teleroboticsdirect force feedback :home/jimgwilliam/JHU/Literature Papers/2008/Mahvash et al/Mahvash et al.\_2008.pdf:pdf 465--471 978-1-4244-2005-6 March Lump Detection 2008 Proc. IEEE Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems 10.1109/HAPTICS.2008.4479994 2008-03 Gwilliam2010 inproceedings Humans can localize lumps in soft tissue using the distributed tac- tile feedback and processing afforded by the fingers and brain. This task becomes extremely difficult when the fingers are not in direct contact with the tissue, such as in laparoscopic or robot-assisted procedures. Tactile sensors have been proposed to characterize and detect lumps in robot-assisted palpation. In this work, we compare the performance of a capacitive tactile sensor with that of the hu- man finger. We evaluate the response of the sensor as it pertains to robot-assisted palpation and compare the sensor performance to that of human subjects performing an equivalent task on the same set of artificial tissue models. Furthermore, we investigate the ef- fects of various tissue parameters (lump size, lump depth, and sur- rounding tissue stiffness) on the performance of both the human finger and the tactile sensor. Using signal detection theory for de- termining tactile sensor lump detection thresholds, the tactile sensor outperforms the human finger in a palpation task. {Human vs. robotic tactile sensing: detecting lumps in soft tissue.} Lump Detection :home/jimgwilliam/JHU/Literature Papers/2010/Gwilliam et al/Gwilliam et al.\_2010.pdf:pdf 21--28 978-1-4244-6821-8 March Lump Detection 2010 2010 IEEE Haptics Symposium 10.1109/HAPTIC.2010.5444685 2010-03 Verner, L. N. Verner Verner, L. N. Okamura, A.M. Okamura Okamura, A.M. Yuh, D.D. Yuh Yuh, D.D. Su, L. Su Su, L. Pezzementi, Z. Pezzementi Pezzementi, Z. Yuh, D. D. Yuh Yuh, D. D. Hsiao, S. S. Hsiao Hsiao, S. S. {Dammann III}, J. F. {Dammann III} {Dammann III}, J. F. Craig, J. C. Craig Craig, J. C. Degirmenci, A. Degirmenci Degirmenci, A. Agarwal, R. Agarwal Agarwal, R. Vagvolgyi, B. Vagvolgyi Vagvolgyi, B. Olenczack, J. B. Olenczack Olenczack, J. B. Yamamoto, T. Yamamoto Yamamoto, T. Bianchi, M. Bianchi Bianchi, M. Jantho, E. Jantho Jantho, E. Gwilliam, J. C. Gwilliam Gwilliam, J. C. Horch, K. Horch Horch, K. Schwartz, N. Schwartz Schwartz, N. Vacharat, A. Vacharat Vacharat, A. Mahvash, M. Mahvash Mahvash, M. Yoshioka, T. Yoshioka Yoshioka, T. Zhou, J. Z. Zhou Zhou, J. Z. Griffiths, P. G. Griffiths Griffiths, P. G. Okamura, A. M. Okamura Okamura, A. M.
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James C. Gwilliam