This document discusses various localization methods for wireless capsule endoscopy (WCE). It categorizes the methods into two groups: magnetic field strength based methods and electromagnetic wave based methods. Magnetic field strength based methods use permanent magnets, coils, or magneto-resistive sensors inside capsules along with external sensors to determine location. Electromagnetic wave based methods use technologies like RFID, RSSI, X-rays, and gamma rays. Each method has advantages and limitations in terms of accuracy, invasiveness, and interference with actuation systems. A future goal is to develop a fully integrated localization and actuation system to enable autonomous capsule operation.
CyberKnife: Radiosurgery System Introductionduttaradio
Radiation source is mounted on a precisely controlled industrial robot.
- Image guidance system(continuous tracking system)
- Eliminates the need of gating techniques and restrictive head frames
CyberKnife: Radiosurgery System Introductionduttaradio
Radiation source is mounted on a precisely controlled industrial robot.
- Image guidance system(continuous tracking system)
- Eliminates the need of gating techniques and restrictive head frames
Radiosurgery is a discipline that utilizes externally generated ionizing radiation in certain cases to inactivate or eradicate a defined target(s) in the head or spine without the need to make an incision. Its uses in Neurosurgery is immense.
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Mems based oct technique can be used to image cancerous tissue at its earlier stage because of its high resolution capability. oct principle can be used in endoscopes to image internal organs.
Magnetic Resonance Imaging or MRI Scanning as we commonly call it is a process where strong magnetic fields and radio waves are used to produce detailed images of the inside of a human body.Contact Us: Open MRI of Orlando 668 N. Orlando Avenue, Suite 1005 Maitland, FL 32751., Tel No: (407) 740-8848, Fax: 407-740-0324, Email: NewPatient@OpenMRIofOrlando.com
Radiosurgery is a discipline that utilizes externally generated ionizing radiation in certain cases to inactivate or eradicate a defined target(s) in the head or spine without the need to make an incision. Its uses in Neurosurgery is immense.
mems based optical coherence tomography imagingGayathri Pv
Mems based oct technique can be used to image cancerous tissue at its earlier stage because of its high resolution capability. oct principle can be used in endoscopes to image internal organs.
Magnetic Resonance Imaging or MRI Scanning as we commonly call it is a process where strong magnetic fields and radio waves are used to produce detailed images of the inside of a human body.Contact Us: Open MRI of Orlando 668 N. Orlando Avenue, Suite 1005 Maitland, FL 32751., Tel No: (407) 740-8848, Fax: 407-740-0324, Email: NewPatient@OpenMRIofOrlando.com
The vital importance of imaging techniques in radiation oncology now extends beyond diagnostic evaluation and treatment planning. Radiotherapy requires input from imaging for treatment planning and execution, when the treatment target is not located on the surface and, inspection and visual confirmation are not feasible. Traditional radiotherapy practices incorporate use of anatomic surface landmarks as well as radiologic correlation with 2D imaging in the form of port films or fluoroscopic imaging. Targets to be irradiated and normal tissues to be spared are delineated on CT scans in the planning process. Recent technical advances have enabled the integration of various imaging modalities into the everyday practice of radiotherapy directly at the linear accelerator. IGRT seeks to address geometric uncertainties in dose placement for target and normal tissues. It has become a routine part of current RT practice. Safe application of IGRT technology requires additional training and careful integration into the clinical process. IGRT reveals changes in anatomy during treatment which challenges conventional practices. IGRT facilitates the precise application of specialized irradiation techniques with narrow safety margins to radiosensitive organs.
This ppt is prepared for zeroth level presentation for the B - TECH project on the topic "Design and Implementation of Improved Authentication System for Android Smartphone Users". we also add the application of the upgraded locking system in lost phone detection procedure
2. WIRELESS CAPSULE ENDOSCOPY (WCE)
LOCALIZATION METHODS
BASED ON MAGNETIC FIELD STRENGTH
MAGNETIC LOCALIZATION FOR PASSIVE CAPSULE ENDOSCOPE
UTILIZATION OF A PERMANENT MAGNET
UTILIZATION OF A SECONDARY COIL
UTILIZATION OF A MAGNETO-RESISTIVE SENSOR
MAGNETIC LOCALIZATION FOR ACTIVE ACTUATION SYSTEM
BASED ON HIGH-FREQUENCY ALTERNATING MAGNETIC FIELD
LOCALIZATION BASED ON INERTIAL SENSING
MEASURING A ROTATIONAL MAGNETIC FIELD
BASED ON ELECTROMAGNETIC WAVES
RADIO WAVES
RECEIVED SIGNAL STRENGTH INDICATOR(RSSI)
RADIO FREQUENCY IDENTIFICATION(RFID)
VISIBLE WAVES
X-RAY
GAMMA RAY
CONTENTS
3. • Endoscopy ?
• Conventional techniques
• WCE is an ingestible pill-like device contains a tiny camera and an illuminating system
• WCE offers patient friendly and painless investigation
• A reliable and precise localization system plays an important role in enhancing the
benefits of WCE.
• Methods for determining the capsule locations are categorized into two,
- magnetic field strength based
- electro magnetic wave based
INTRODUCTION
4. DATA
RECORDER
COMPUTER
Data Acquisition & Storage
Of Data On Computer
Produces two images per
second, approximately 2,600
high quality images.
Movement Of Capsule Through The
Digestive System
6. LOCALIZATION METHODS BASED ON MAGNETIC FIELD STRENGTH
• This method is used because of 2 main reasons
* static and low frequency magnetic signals can pass through human tissue without
attenuation.
* magnetic tracking is a non line of sight method .
• The negligible interaction between magnetic field and human body
• The problem is the conflict between 2 systems due to interference of 2 applied magnetic
fields.
* Magnetic localization for passive capsule endoscope
* Magnetic localization for active actuation system
7. UTILIZATION OF A PERMANENT MAGNET ENCLOSED INSIDE A
CAPSULE
Why a permanent magnet ?
The majority of magnetic tracking systems generate magnetic field through integrating
a permanent magnet inside the capsule.
Magnetic flux intensities originating from the magnet vary their magnitudes and direction
depending on the magnets location and orientation.
Magnetic sensors are placed outside of a patients body to measure these persistent
magnetic signals.
8. UTILIZATION OF A SECONDARY COIL EMBEDDED IN A CAPSULE
The spatial information of the capsule can be obtained through utilizing a coil enclosed
inside a capsule.
The field seen by the receiving coil is,
UTILIZATION OF A 3-AXIS MAGNETO-RESISTIVE SENSOR
A 3-axis magneto-resistive sensor used to measure the intensity of the external magnetic
field generated by 3 energized coils fixed on the patients body.
The 3 coils are excited in turn by square waves with the same period of 0.03s,and at the
end of every cycle, there is a break period of 0.1s when the coils are not activated to
estimate earth’s magnetic field magnitudes.
9. MAGNETIC LOCALIZATION FOR ACTIVE ACTUATION SYSTEM
• These systems were designed to work effectively with their own magnetic actuation
mechanisms.
* localization based on high frequency alternating magnetic field
* localization method based on inertial sensing
* based on measuring a rotational magnetic field by rotating an external permanent
magnet.
LOCALIZATION BASED ON HIGH FREQUENCY ALTERNATING MAGNETIC FIELD
• It uses a spiral structure on the surface of a capsule in which a permanent magnet is integrated
• 3 pairs of coils were placed in three perpendicular axial directions to generate an external
rotating magnetic field around the patient’s body.
• The spiral structure rotate the capsule by applying this magnetic field on the magnet can propel
it forward and backward.
• The frequency of rotating magnetic field should not be higher than 10Hz
10. LOCALIZATION METHOD BASED ON INERTIAL SENSING
• Magnetic steering , utilized a 6 degree-of-freedom robotic arm to carry a permanent magnet
at the end.
• 4 cylindrical magnets were mounted uniformly on the body of a capsule in order to create a
magnetic link between body and the external permanent magnet.
• By this design , the capsule can be dragged and steered effectively with the assistance of the
magnetic interaction.
• For the localization function , a 3-axis accelerometer was inserted into the capsule.
.
11. LOCALIZATION BASED ON MEASURING A ROTATIONAL MAGNETIC FIELD
GENERATED BY ROTATING AN EXTERNAL PERMANENT MAGNET
• It uses an endoscopic capsule with a helical architecture , created an external rotational
magnetic field to rotate 2 permanent magnets embedded in the endoscopic device.
• instead of utilizing 6 bulky coils around the patients body , here rotates a big parallel piped
permanent magnet made by 7 smaller rectangular magnets to generate a rotational mag.field.
• The magnetic field generator was driven by an electrical motor mounted on a manipulator , so
that it could spin and its position can be changed during the control process of capsule.
• When the external permanent magnet is spinning , field strength changes periodically and its
highest or lowest value occurs at XZ/XY plane.
12. LOCALIZATION METHODS BASED ON ELECTROMAGNETIC WAVES
• These methods are not influenced by magnetic field generated for the actuation purpose.
• Radio frequency has been widely used for locating an object in both outdoor and indoor
environments.
- Received Signal Strength Indicator(RSSI)
- Radio Frequency Identification(RFID)
13. 1. RECEIVED SIGNAL STRENGTH INDICATOR(RSSI)
The transmitter built inside the capsule wirelessly sends endoscopic images ,which
are captured during its travel along the inner parts ,to 8 receivers placed uniformly
on the exterior of the patient abdomen.
The low accuracy achieved by this localization system can make it impossible to
provide feedback for actuation systems.
2. RADIO FREQUENCY IDENTIFICATION(RFID)
RFID is also investigated in radio frequency based localization systems for WCE.
A cubic antenna array is built surrounding a patient’s body to track a RFID tag
integrated inside a capsule.
14. VISIBLE WAVES
Visible waves cannot penetrate human body , it has still been exploited for the aim
of capsule localization through computer vision.
Inside the WCE ,white light emitting diodes(LED) illumination sources are used in
conjunction with a miniature camera for capturing images .
X-RAY
Beside the application of medical imaging , X-rays can also be exploited to track an
object
Fluoroscopy
GAMMA RAY
A gamma ray has not been employed in the localization approaches for WCE , was
exploited in gamma scintigraphy technique .
15. OTHER LOCALIZATION METHODS
1) MRI (MAGNETIC RESONANCE IMAGING)
Diagnostic imaging technique used widely in medical clinics.
1) ULTRA SOUND
A potential method for localization in soft tissue.
16. Localization methods extra extra accuracy interference real health
space power time effects
passive permanent magnet Yes No High Yes Yes No
WCE secondary coil Yes Yes Mdm Yes -- No
magneto-resistive
sensor Yes Yes Mdm Yes No No
Active HF alternating m.f Yes No High No Yes --
WCE Inertial sensing Yes Yes Low No -- No
Rotating external
permanent magnet Yes Yes Mdm No -- No
EM Visible No No Low No --
Waves X-ray No No -- No Yes Yes
Gamma Yes No -- No Yes Yes
Others MRI Yes Yes High -- Yes Little
Ultra sound Yes Yes -- No Yes Little
COMPARISON OF LOCALIZATION METHODS
17. ADVANTAGES
Painless, no side effects or complications
Miniature size , so can move easily through digestive tract.
Accurate , precise and effective
Images taken are of high quality which are sent almost instantaneously to the data recorder for
storage.
Made of bio-compatible material , doesn’t cause any harm to the body.
DRAWBACKS
Patients with gastrointestinal structures or narrowing are not good candidates for this procedure.
The pill will get stucked , if there is a partial obstruction in the small intestine.
Impossible to control camera behavior.
18. CONCLUSION
WCE with the capability of moving automatically in the digestive tract under an
external control will be introduced in the near future.
Such an active system requires a sufficiently accurate localization system
None of the existing methods could offer a complete solution to address the challenging
capsule localization problem.
A future WCE is expected to have fully robotic capabilities such that it will be able to
accomplish both diagnosis and disease treatment
In order to achieve such an autonomous WCE , building a complete localization system
which is ,
- acceptably accurate in real-time
- minimally invasive
- work with different actuation mechanisms
- easily implementable