Method to Achieve High Frame Rates in a Scanning Fiber Endoscope

2011 ◽  
Vol 5 (3) ◽  
Author(s):  
Matthew J. Kundrat ◽  
Per G. Reinhall ◽  
Eric J. Seibel
Keyword(s):  
Flexible Endoscopy ◽  
Initial Position ◽  
The Body ◽  
Target Area ◽  
Imaging Device ◽  
Velocity Imaging ◽  
Time To Build ◽  
Image Center ◽  
Scanning Fiber Endoscope ◽  
Scanning Fiber

A new and miniature imaging device is being developed to allow flexible endoscopy in regions of the body that are difficult to reach. The scanning fiber endoscope employs a single scanning optical fiber to illuminate a target area, while backscattered light is detected one pixel at a time to build a complete image. During each imaging cycle the fiber is driven outward in a spiral pattern from its resting state at the image center to the outer fringe of the image. At this point, the fiber is quickly driven back to its initial position before acquiring a subsequent frame. This work shortens the time between successive images to achieve higher overall frame rates by applying a carefully timed input, which counteracts the tip motion of the scanning fiber, quickly forcing the scanning fiber to the image center. This input is called motion braking and is a square wave function dependent upon the damped natural frequency of the scanning fiber and the instantaneous tip displacement and velocity. Imaging efficiency of the scanning fiber endoscope was increased from 75–89% with this implementation.

Self-Contained Image Recalibration in a Scanning Fiber Endoscope Using Piezoelectric Sensing

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
I. L. Yeoh ◽  
P. G. Reinhall ◽  
M. C. Berg ◽  
E. J. Seibel
Keyword(s):  
Image Quality ◽  
Optical Fiber ◽  
Base Station ◽  
Major Step ◽  
Imaging Device ◽  
Calibration Chamber ◽  
Scanning Fiber Endoscope ◽  
The Cost ◽  
Optical Calibration ◽  
Scanning Fiber

The scanning fiber endoscope (SFE) is a new ultrathin (1.2 mm diameter) medical imaging device that utilizes a unique mechanical scanning technique to image large (120 deg) fields of view (FOVs). A single 80 μm optical fiber is circularly vibrated by a piezo-electric tube to illuminate a field while the reflected light is collected to construct an image pixel-by-pixel. Accurate scanning of the optical fiber is paramount to image quality. Previously, an optical calibration chamber in the base station was used to calibrate the scanning of the optical fiber. This analytical and experimental work eliminates the use of the calibration chamber by implementing a new piezoelectric sensing approach enabling self-contained recalibration to maintain high-image quality during long medical procedures and also reducing the cost, size, and power consumption of the SFE. This work provides a major step toward self-calibration through adaptive control without additional sensors.

scholarly journals An Electro-Thermal Actuation Method for Resonance Vibration of a Miniaturized Optical-Fiber Scanner for Future Scanning Fiber Endoscope Design

Actuators ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 21 ◽  
Author(s):  
Aydin Aghajanzadeh Ahrabi ◽  
Mandeep Kaur ◽  
Yasong Li ◽  
Pierre Lane ◽  
Carlo Menon
Keyword(s):  
Optical Fiber ◽  
Single Mode ◽  
The Body ◽  
Tube Diameter ◽  
Experimental Results ◽  
Thermal Excitation ◽  
Transthoracic Needle Biopsy ◽  
Scanning Fiber Endoscope ◽  
Scanning Fiber ◽  
Insertion Tube

Medical professionals increasingly rely on endoscopes to carry out many minimally invasive procedures on patients to safely examine, diagnose, and treat a large variety of conditions. However, their insertion tube diameter dictates which passages of the body they can be inserted into and, consequently, what organs they can access. For inaccessible areas and organs, patients often undergo invasive and risky procedures—diagnostic confirmation of peripheral lung nodules via transthoracic needle biopsy is one example from oncology. Hence, this work sets out to present an optical-fiber scanner for a scanning fiber endoscope design that has an insertion tube diameter of about 0.5 mm, small enough to be inserted into the smallest airways of the lung. To attain this goal, a novel approach based on resonance thermal excitation of a single-mode 0.01-mm-diameter fiber-optic cantilever oscillating at 2–4 kHz is proposed. The small size of the electro-thermal actuator enables miniaturization of the insertion tube. Lateral free-end deflection of the cantilever is used as a benchmark for evaluating performance. Experimental results show that the cantilever can achieve over 0.2 mm of displacement at its free end. The experimental results also support finite element simulation models which can be used for future design iterations of the endoscope.

scholarly journals Scanning Fiber Endoscope Improves Detection of 5-Aminolevulinic Acid–Induced Protoporphyrin IX Fluorescence at the Boundary of Infiltrative Glioma

2018 ◽  
Vol 113 ◽  
pp. e51-e69 ◽  
Author(s):  
Evgenii Belykh ◽  
Eric J. Miller ◽  
Danying Hu ◽  
Nikolay L. Martirosyan ◽  
Eric C. Woolf ◽  
...  
Keyword(s):  
Aminolevulinic Acid ◽  
Protoporphyrin Ix ◽  
Scanning Fiber Endoscope ◽  
Scanning Fiber

scholarly journals The Analysis with Finite Elements of the Elasto-plastic Behaviour of the Spinal Immobilizers - in the Case of Comminutive Fractures

2019 ◽  
Vol 57 (2) ◽  
pp. 253-264
Author(s):  
Bogdan Florin Toma ◽  
Constantin Nanu ◽  
Cezar Popescu ◽  
Razvan Vladimir Socolov ◽  
Vasile-Eduard Rosu ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Initial Position ◽  
The Body ◽  
Elastic Behaviour ◽  
Element Analysis ◽  
Clinical Observations ◽  
Clinical Investigations ◽  
Extension Force ◽  
Bone Fragments ◽  
Tension State

In this paper it is presented a comparative theoretical study - performed by finite element analysis (FEA), of the tension state that appears at the level of the spine, as well as in the areas adjacent to it, under the following conditions: a) the existence of a comminutive fracture at the level of the vertebra T11; b) of the external immobilization of the body through a Lombax orthesis (LO) or of the internal immobilization of the column by means of a spinal fixator (SF); c) of performing some basic flexion or extension movements. In this study, both flexural force and extension force varied on three levels. The results of the comparative theoretical study were supplemented with the clinical observations obtained from a number of 52 patients who had suffered comminutive fractures in the T11 vertebra and who were treated - by external immobilization, in the Lombax orthesis or were surgically treated - by applying a trapped spinal fixator on the T10-T12 vertebrae. The study had demonstrated that, by immobilizing the body in the Lombax orthesis, following the application of the flexion or extension movement, the mobility of the body is low, the bone fragments move less distances by about 12% against to their displacement under the condition of immobilizing the column by a spinal fixator. Although, in the latter case, the displacements of the bone fragments are greater, the elastic behaviour of the spinal fixator determines the returning of the fragments and of the spine to the initial position as well as the distance between the vertebrae. Clinical investigations on patients treated by external immobilization of the body in the Lombax orthesis show that the values of the local kyphosis angle (LKA) are about 30% lower than the values of the same parameter obtained under the surgical treatment.

scholarly journals From the lateral edge to the center of the cortex: The development of the human insula

Neuroforum ◽  
2018 ◽  
Vol 24 (4) ◽  
pp. A151-A158
Author(s):  
Gundela Meyer
Keyword(s):  
Pyramidal Neurons ◽  
Radial Glia ◽  
Brain Activity ◽  
Prenatal Development ◽  
Initial Position ◽  
The Body ◽  
Cortical Region ◽  
Lateral Edge ◽  
External Capsule ◽  
Adjacent Structures

Abstract The human insula is a key node in a neuronal network which integrates interoceptive stimuli from the own body, and exteroceptive stimuli from the environment, and thus maintains the autonomic, emotional and socio-cognitive homeostasis of the body. In the last years, the insula has come into the focus of attention. Comparative anatomical studies showed that in many species the insula forms the lateral edge of the cortex. Very little is known about the prenatal development of the human insula, which is the first cortical region to mature. The origin of the pyramidal neurons for the insula is a small sector of the proliferating ventricular/subventricular zone at the cortico-striatal boundary (CSB). The CSB contains the radial glia cells, which are stem cells and give rise to a dense fascicle of radial glia processes. This fascicle traverses the external capsule and serves as a migration substrate for the neuroblasts on their way from the CSB into the insula. Around the 10/11th week of gestation, the lateral ventricle and its adjacent structures including the CSB bend in a C-shaped fashion. The insula now develops between a dorsal, fronto-parietal and a ventral, temporal CSB, which provide descending and ascending streams of neuroblasts, respectively, migrating along the radial glia fascicle. As a consequence of the ventricular rotation during ontogenesis, the human insula changes its initial position at the lateral edge of the cortex to its final central location, which reflects its integrative functions in brain activity.

Near-infrared dental imaging using scanning fiber endoscope

2018 ◽  
Author(s):  
Yaxuan Zhou ◽  
Alireza Sadr ◽  
Robert C. Lee ◽  
Eric J. Seibel
Keyword(s):  
Near Infrared ◽  
Dental Imaging ◽  
Scanning Fiber Endoscope ◽  
Scanning Fiber

Evaluation of Hand-Eye Coordination Based on Brain Activity

2015 ◽  
Vol 19 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Satoshi Miura ◽  
◽  
Yo Kobayashi ◽  
Kazuya Kawamura ◽  
Masatoshi Seki ◽  
...  
Keyword(s):  
Body Image ◽  
Brain Imaging ◽  
Brain Activity ◽  
The Body ◽  
Surgical Simulator ◽  
Surgical Robots ◽  
Imaging Device ◽  
Hand Eye Coordination

Surgical robots have improved considerably in recent years, but their intuitive operability, and thus their user interoperability, has yet to be quantitatively evaluated. Thus, we propose a method for measuring a user’s brain activity while operating such a robot, to better enable the design of a robot with intuitive operability. The objective of this study was to determine the angle and radius between an endoscope and manipulator that best allows the user to perceive the manipulator as being part of their own body. In the experiments, a subject operated a hand controller to position the tip of a virtual slave manipulator onto a target in a surgical simulator while his/her brain activity was measured using a brain imaging device. The experiment was carried out several times with the virtual slave manipulator configured in a variety of ways. The results show that the amount of brain activity is significantly greater with a particular slave manipulator configuration. We concluded that the hand-eye coordination between the body image and the robot should be closely matched in the design of a robot having intuitive operability.

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