Publications
52 results found
Saso S, Chatterjee J, Thum Y, et al., 2013, Uterine viability following allogeneic uterine transplantation in a rabbit model, BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Vol: 120, Pages: 185-185, ISSN: 1470-0328
Clancy NT, Stoyanov D, James DRC, et al., 2012, Multispectral image alignment using a three channel endoscope <i>in vivo</i> during minimally invasive surgery, BIOMEDICAL OPTICS EXPRESS, Vol: 3, Pages: 2567-2578, ISSN: 2156-7085
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- Citations: 23
Clancy NT, Elson DS, 2012, A snapshot endoscopic polarisation imaging system, The Hamlyn Symposium on Medical Robotics, Pages: 105-106
Clancy NT, Sauvage V, Saso S, et al., 2012, Registration and analysis of multispectral images acquired during uterine transplantation surgery, OSA Biomed
Clancy NT, Stoyanov D, Yang G-Z, et al., 2012, Stroboscopic illumination scheme for seamless 3D endoscopy, Conference on Advanced Biomedical and Clinical Diagnostic Systems X, Publisher: Society of Photo-optical Instrumentation Engineers (SPIE), ISSN: 0277-786X
Clancy NT, Li R, Rogers K, et al., 2012, Development and evaluation of a light emitting diode endoscopic light source, Conference on Advanced Biomedical and Clinical Diagnostic Systems X, Publisher: Society of Photo-optical Instrumentation Engineers (SPIE), ISSN: 0277-786X
Clancy NT, Stoyanov D, Maier-Hein L, et al., 2011, Spectrally-encoded fibre-based structured lighting probe for intraoperative 3D imaging, Biomedical Optics Express, Vol: 2, Pages: 3119-3128, ISSN: 2156-7085
Three dimensional quantification of organ shape and structure during minimally invasive surgery (MIS) could enhance precision by allowing the registration of multi-modal or pre-operative image data (US/MRI/CT) with the live optical image. Structured illumination is one technique to obtain 3D information through the projection of a known pattern onto the tissue, although currently these systems tend to be used only for macroscopic imaging or open procedures rather than in endoscopy. To account for occlusions, where a projected feature may be hidden from view and/or confused with a neighboring point, a flexible multispectral structured illumination probe has been developed that labels each projected point with a specific wavelength using a supercontinuum laser. When imaged by a standard endoscope camera they can then be segmented using their RGB values, and their 3D coordinates calculated after camera calibration. The probe itself is sufficiently small (1.7 mm diameter) to allow it to be used in the biopsy channel of commonly used medical endoscopes. Surgical robots could therefore also employ this technology to solve navigation and visualization problems in MIS, and help to develop advanced surgical procedures such as natural orifice translumenal endoscopic surgery.
Clancy NT, Clark J, Noonan DP, et al., 2011, Light sources for single access surgery, Surgical Innovation, Vol: 19, Pages: 130-140
Background. Minimally invasive surgical techniques such as single access and natural orifice translumenal endoscopic surgery (NOTES) aim to reduce the number of external scars on the patient but impose restrictions on the space available for the light source within the endoscope and, therefore, the size of the field of view that can be sufficiently illuminated. Materials and Methods. This article presents and compares a number of illumination methods (xenon, light-emitting diodes, laser/phosphor, supercontinuum laser) that could be applied in single-access, robotic, and NOTES procedures. The luminance, spectral content, and intensity profile of each source was measured. Standardized images of each illuminating an abdominal simulator were assessed by a group of surgeons to provide an initial clinical impression. Results. The xenon source was found to have the highest luminance when used with a standard laparoscopic light cable, but this was significantly reduced when used with a small cable suitable for single-access applications. The supercontinuum laser–based light source had brightness comparable to the xenon, which was supported by the surgical test group observations. Conclusions. The supercontinuum fiber probe is a potential alternative to xenon light sources for use in single-access surgery with its comparable luminance, small diameter, flexibility, and even illumination. An initial in vivo test is described, providing a guide for future development
Clancy NT, Mylonas GP, Yang GZ, et al., 2011, Gaze-contingent autofocus system for robotic-assisted minimally invasive surgery, EMBC 2011
A gaze-contingent autofocus system using an eye-tracker and liquid lens has been constructed for use with a surgical robot, making it possible to rapidly (within tens of milliseconds) change focus using only eye-control. This paper reports the results of a user test comparing the eye-tracker to a surgical robot’s in-built mechanical focusing system. In the clinical environment, this intuitive interface removes the need for an external mechanical control and improves the speed at which surgeons can make decisions, based on the visible features. Possible applications include microsurgery and gastrointestinal procedures where the object distance changes due to breathing and/or peristalsis.
Clancy NT, Stoyanov D, Yang GZ, et al., 2011, Design of a miniature multispectral structured lighting probe for endoscopic use, Hamlyn Symposium on Medical Robotics
Clancy NT, Stoyanov D, Yang GZ, et al., 2011, An endoscopic structured lighting probe using spectral encoding, Novel Biophotonic Techniques and Applications
Recovering the three dimensional (3D) surface shape of tissues in minimally invasive surgery (MIS) is important for developing advanced image-guidance and navigation systems. Passive techniques for 3D reconstruction based on computational stereo are limited by the saliency of tissue texture and the view-dependent reflectance characteristics of the scene. Structured lighting provides a viable alternative by projecting known features onto the tissue surface. However, the correspondence problem (distinguishing individual projected features computationally) becomes difficult in tissue due to the presence of occlusions. Furthermore, miniaturisation of a light projection system for use in MIS, while maintaining the required light intensity, is a significant challenge.In this paper, a fibre-based probe is described that projects a spectrally-encoded pattern onto the target surface from its distal end. A dispersed broadband light source is used to project features of varying spectral content. The dominant wavelengths of imaged spots may be deduced from the RGB values of a standard colour camera using an algorithm that locates each colour on a chromaticity diagram. The results show that individual spots of a specified wavelength may be segmented and their centres of mass calculated, despite varying background colour. The probe has also been demonstrated on ex vivo tissue.
Clancy NT, Stoyanov D, James DRC, et al., 2011, Three-dimensional imaging techniques and applications for minimally invasive surgery, ECI Advances in Optics for Biotechnology, Medicine and Surgery XII
Three dimensional quantification of organ shape and structure during minimally-invasive surgery (MIS) could enhance precision by allowing registration of multi-modal or pre-operative image data (US/MRI/CT) and the live optical image to the surgeon. Surgical robots could also employ this technology to solve navigation and visualisation problems in MIS and developing procedures such as natural orifice translumenal endoscopic surgery (NOTES). Two complementary methods of 3D surface measurement to enhance the surgeon’s view providing registered image information are presented.In our case the registration is performed on in vivo multispectral reflectance images, which are acquired sequentially to build up a picture of light absorbance in the field of view and indicate chromophore levels (e.g., haemoglobin). Breathing artefacts and camera movement lead to misalignments. A three channel endoscope addresses this by using stereo cameras to track movement of tissue features in 3D and apply a correction to the multispectral images. We present processed multispectral data reprojected onto the stereo view.Where no optical features are detected (e.g. on smooth, homogeneous tissues), structured illumination may be used. To account for occlusions where a projected feature may be hidden from view and/or confused with a neighbouring point, a flexible multispectral structured illumination probe has been developed that labels each projected point with a specific wavelength using a supercontinuum laser. When imaged by the endoscope camera they can then be segmented using their RGB values, and their 3D coordinates calculated after camera calibration. The probe itself is sufficiently small (1.7 mm) to allow it to be used in the biopsy channel of commercial endoscopes.Both complementary 3D instruments are designed to have the minimal effect on the surgical workflow being compatible with existing platforms (da Vinci Surgical System) or standard endoscope biopsy channels.
Clancy NT, Stoyanov D, Sauvage V, et al., 2010, Three dimensional tracking and image registration using a da Vinci triple endoscope, Hamlyn Symposium on Medical Robotics
Clancy NT, Nilsson GE, Anderson CD, et al., 2010, A new device for assessing changes in skin viscoelasticity using indentation and optical measurement, SKIN RESEARCH AND TECHNOLOGY, Vol: 16, Pages: 210-228, ISSN: 0909-752X
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- Citations: 25
James DRC, Sauvage V, Clancy NT, et al., 2010, Towards intra operative diagnosis of mesenteric oxygenation with hyperspectral imaging, Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) 12th World Congress of Endoscopic Surgery
Clancy NT, Stoyanov D, Sauvage V, et al., 2010, A Triple Endoscope System for Alignment of Multispectral Images of Moving Tissue, Biomedical Optics
A three-channel rigid endoscope allowing simultaneous recording of stereoscopic and multispectral images has been developed. With appropriate calibration, the system allows for registration of multispectral images where the tissue or camera is moving.
O'Doherty J, McNamara P, Clancy NT, et al., 2009, Comparison of instruments for investigation of microcirculatory blood flow and red blood cell concentration, Journal of Biomedical Optics, Vol: 14
The use of laser Doppler perfusion imaging (LDPI) and laser speckle perfusion imaging (LSPI) is well known in the noninvasive investigation of microcirculatory blood flow. This work compares the two techniques with the recently developed tissue viability (TiVi) imaging system, which is proposed as a useful tool to quantify red blood cell concentration in microcirculation. Three systems are evaluated with common skin tests such as the use of vasodilating and vasoconstricting drugs (methlynicotinate and clobetasol, respectively) and a reactive hyperaemia maneuver (using a sphygmomanometer). The devices investigated are the laser Doppler line scanner (LDLS), the laser speckle perfusion imager (FLPI)—both from Moor Instruments (Axminster, United Kingdom)—and the TiVi imaging system (WheelsBridge AB, Linköping, Sweden). Both imaging and point scanning by the devices are used to quantify the provoked reactions. Perfusion images of vasodilatation and vasoconstriction are acquired with both LDLS and FLPI, while TiVi images are acquired with the TiVi imager. Time acquisitions of an averaged region of interest are acquired for temporal studies such as the reactive hyperaemia. In contrast to the change in perfusion over time with pressure, the TiVi imager shows a different response due its measurement of blood concentration rather than perfusion. The responses can be explained by physiological understanding. Although the three devices sample different compartments of tissue, and output essentially different variables, comparisons can be seen between the three systems. The LDLS system proves to be suited to measurement of perfusion in deeper vessels, while FLPI and TiVi showed sensitivity to more superficial nutritional supply. LDLS and FLPI are insensitive to the action of the vasoconstrictor, while TiVi shows the clear boundaries of the reaction. Assessment of the resolution, penetration depth, and acquisition rate of each instrument show complimentary featur
Leahy MJ, Enfield JG, Clancy NT, et al., 2007, Biophotonic methods in microcirculation imaging, Medical Laser Application, Vol: 22, Pages: 105-126
Visible and near-infrared light, particularly in the wavelength region of 600–1100 nm, offer a window into human and animal tissues due to reduced scattering and absorption. We review the main biophotonic methods applied to visualisation and assessment of the microcirculation and document the progress made over the past 10 years in particular. Applications, particularly in human skin, are of special topical importance due to an improved knowledge of its role and its value as a surrogate for other organs in drug testing at a time when drug development is under severe pressure.
Clancy NT, Leahy MJ, Nilsson GE, et al., 2007, Analysis of skin recovery from mechanical indentation using diffuse lighting and digital imaging, Diffuse Optical Imaging of Tissue
Clancy NT, Leahy MJ, Nilsson GE, 2006, Non-invasive assessment of the mechanical properties of human skin - investigation of effective age using an optical method, Biomedical Optics
Clancy NT, Leahy MJ, 2005, Effect of glucose on the optical properties of arterial blood using Mie theory simulations, Diagnostic Optical Spectroscopy in Biomedicine III
Leahy MJ, Clancy NT, O'Doherty J, 2004, Optimising reflection-based pulse oximeters, Biomedical Optics
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