PHOTOACOUSTIC PROBE FOR TUMOR DETECTION

Document Sample
PHOTOACOUSTIC PROBE FOR TUMOR DETECTION Powered By Docstoc
					PHOTOACOUSTIC PROBE
FOR TUMOR DETECTION


                     HAIFENG WANG
                     SUBHASHINI PAKALAPATI
                     VU TRAN

Department of Electrical and Computer Engineering
       University of Massachusetts Lowell

                       1
               OUTLINE
 Introduction
 Principle of Ultrasound
 What is Photoacoustic (PA)
 Fiber-optic Source and Receiver
 System of PA
 How to fabricate
 How PA system can detect tumor
 Advantages and Disadvantages
 Timeline
 Tasks
 Reference

                        2
             INTRODUCTION

 Cancer killed ~570 000 people in 2010 in the USA.

 Lot of methods to detect/predict tumor: US, x-ray,
  CT, MRI, PET, SPECT, etc.

 Photoacoustic (PA) takes advantage of fiber optic
  and ultrasound to detect tumor




                           3
PRINCIPLE OF ULTRASOUND




 Transducer emit ultrasound wave and get signals
  back from object
 D= t.v
 Scan volume to get image

                        4
   WHAT IS PHOTOACOUSTIC?
 Conversion of photons to acoustic wave due to
  absorption and localized thermal excitation.

 Pulses of light is absorbed, energy will be radiated
  as heat.

 Heat causes detectable sound waves due to
  pressure variation.



                            5
PHOTOACOUSTIC (Cont.)




          6
DIAGRAM OF A TYPICAL PA SYSTEM




 Themo-elastic Ultrsound Generation
 Extrinsic fiber hydrophone, based on a Fabry-Perot
  interferometer
                           7
  FIBER OPTIC ULTRASONIC SOURCE
BASED ON OPTO-ACOUSTIC CONVERSION




                8
  FIBER OPTIC ULTRASONIC RECEIVER
BASED ON ACOUSTO-OPTIC CONVERSION




                9
TRANSMISSION STRUCTURE

2D gold nanoparticle array sandwiched
between a transparent substrate and a
PDMS layer




                    10
       GOLD NANOSTRUCTURE




The top view (a) and sketch of the side view( b) of the gold nanostructure.




                                     11
DETECTION OF TUMOR USING PAI

 Tumors have dense
  and unorganized
  vasculature.

 High density of blood
  vessels in tumors
  enhances PAI contrast.




                           12
      DETECTION OF TUMOR
            (CONT.)
Endogenous PA contrast:
   • Melanin
   • Oxy Hemoglobin
   • Deoxy Hemoglobin
Exogenous PA contrast (Highly sensitive to deeply
  situated tumors):
   • Au NP
   • Alexa Fluor
   • Indocyanine Green

                         13
ADVANTAGES                DISADVANTAGES

1. Ability to detect deeply 1. Limited Path length
   situated tumor and its 2. Temperature Dependence
   vasculature              3. Weak absorption at short
2. Monitors angiogenesis       wavelengths
3. High resolution
4. Compatible to Ultra
   Sound
5. High Penetration depth


                         14
                               TIMELINE
         Time        03/01 03/08   03/15 03/22   03/29 04/05   04/12 04/19 04/26   05/03
Task

Presentation 1
(Background,
Preparation and
plan)
Literature
Review
First Draft of
Paper
Improvisation of
first draft
Presentation 2
(Progress,results)
Second draft of
paper
Improvisation of
second draft
 Presentation 3
Final Review
Paper




                                            15
                      TASKS
• HAIFENG WANG
   – Principle of Photoacoustic
   – Fabricate PA structure
• SUBHASHINI PAKALAPATI
   – Principle and procedure of tumor detection using PA
   – AuNP enhanced
• VU TRAN
   – Compare other methods to detect tumor
   – AuNP enhanced


                           16
                      REFERENCES
[1] Jemal,A. et al. Cancer Statistics, 2010. CA CancerJ.Clin. 60, 277–300
[2] Hou, Y., et al., Optical generation of high frequency ultrasound using two-
dimensional gold nanostructure. Applied Physics Letters, 2006. 89(9): p.
093901-3.
[3] Mallidi, S., G.P. Luke, and S. Emelianov, Photoacoustic imaging in cancer
detection, diagnosis, and treatment guidance. Trends Biotechnol, 2011.
[4] Tang, M.X., et al., Photoacoustics, thermoacoustics, and acousto-optics for
biomedical imaging. Proc Inst Mech Eng H, 2010. 224(2): p. 291-306.
[5] Wang, X., et al., Photoacoustic tomography: a potential new tool for
prostate cancer. Biomed Opt Express, 2011. 1(4): p. 1117-1126.




                                      17
THANK YOU




    18

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:19
posted:2/7/2012
language:English
pages:18