Device for Directed Pleural Biopsy

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Device for Directed Pleural Biopsy

• Group 5 Bridget Mollner
• Mario Martinez
• Shawna McGehee
• Mentor Martin Mayse, M.D.
• Director of Interventional Pulmonology
• Washington University in St. Louis

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Background

• Why a device for Directed Pleural Biopsy?
• 1.5 million people develop pleural effusions each
  year.
• Current surgical procedures have not changed in
  the last couple decades.
• It is a very difficult condition to diagnose.

University of California, San Diego
http//meded.ucsd.edu/isp/1994/im-quiz/pleuaden.ht
m
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Background

• Design a useful device or method that is
• Used to obtain a biopsy of the parietal pleura
  (1mm range in size)
• Directed by imaging to determine the abnormal
  tissues
• Does not require a chest tube to be left in the
  patient

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Background

• Design Specifications
• The size of the insertion hole should be less
  than 5 mm in diameter
• The procedure must be able to obtain a biopsy
  that is in the 1mm range
• Length of device needs to be less than 45 cm
• The weight of the device should be less than 2 kg
• Materials used should be biocompatible, suck as
  plastic, silicone, teflon
• Budget under 20,000
• General anesthesia should not be required
• Patient should be able to go home that day after
  surgery

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Design Alternatives

• Light Detection and Ranging (LIDAR)
• measures properties of scattered light to find
  range and/or other information of a distant
  target
• Pros ability to see through smoke
• Cons size of device image produced cost

Witness and Response September 11 Acquisitions
at the Library of the Congres (Geography and Map
Division) http//www.loc.gov/exhibits/911/911-maps
.html LIDAR http//www.jhu.edu/dogee/mbp/researc
h/lidar/main.htm
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Design Alternatives

• Confocal Microscopy
• A laser beam is passed through the endoscope
  using an optical fiber, and an image is obtained
  by filtering out light from regions that are not
  in focus.

EndoMicroscopy http//www.endomicroscopy.org/Tour/
normal/4.asp
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Design Alternatives

• Confocal Microscopy
• Pros can be used to see through milky solution
• Cons price, unsure if itll work through pleural
  fluid, unsure as to what its magnification can be

Synthetic Aperture Confocal Imaging
http//graphics.stanford.edu/papers/confocal/levoy
-confocal-sig04.pdf
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Design Alternatives

• Fluorescent Tagging
• Photosensitizers (which have high binding
  specificity to tumor cells) are taken into the
  body and are exposed to blue light (380-440 nm)
  under which they fluoresce.
• Pros safe, easy to add this wavelength to
  current technology
• Cons best results 6 hrs of taking
  photosensitizers, little research in pleural
  space, FDA

R L Prosst, S Winkler, E Boehm, J Gahlen.
Thoracospcoic Fluorescence Diagnosis of Pleural
Malignancies Experiemental Studies. Thorax.
2002 57, 1005-1009
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Design Alternatives

• Balloon on a Stick (BOS) system
• A balloon is filled with saline, so that the
  pleural walls can be imaged through a clear
  solution, avoiding absorption from the
  potentially colored and cloudy pleural fluid
• Pros simple, inexpensive
• Cons loosing balloon in patient, overall safety

EP Lab Digest. http//www.eplabdigest.com/article
/974
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Design Alternatives

• Infrared Technology
• Temperature measurements allow physiological or
  pathological changes in the tissue to be
  detected. Therefore, abnormal tissues in the
  pleural space can be detected.
• Pros good visualization on real time basis can
  see through flowing blood safe for use in humans
• Cons can we identify other abnormal tissues
  beyond cancerous tumor cells?

http//www.cardio-optics.com/video.asp
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Design Alternatives

• Ultrasound
• Uses high frequency sound waves that are
  reflected by tissue to varying degrees to produce
  a 2D or 3D image, traditionally on a TV monitor
• Pros small transducers available familiar
  images flexibility as to frequency (high
  frequency ultrasounds
• Cons size of device interpreting signals
  training required

Ultrasound http//en.wikipedia.org/wiki/Ultrasound
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Choosing a Design

• Develop Criteria and Weights
• Brainstorming as individual and in groups
• Came up with 16 different criteria
• Ranked them individually (from 1 to 16)
• Use Average Ranking to Assign Weights
• Rank 1, Weight 10
• Rank 2, Weight 9

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Choosing a Design
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Choosing a Design

• Assess how each Technology performs according to
  each criteria
• If technology fulfills criteria well, Assign a 5
• If technology does not fulfill criteria well,
  Assign a 1
• Each person does assessment, then we average
  results
• Multiply AVG Assessment with weights, and sum
  points

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Choosing a Design
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Infrared Technology

• Chosen because it provides a good image, is safe,
  is relatively inexpensive, and its easy to adjust
  to current tools (use fiber optics)
• Other considerations
• License Technology (US Patent 6,178,346)
• Image Output Device
• Further Specifications
• Wavelength 1600 nm
• Yellow or Red pleural fluid absorb wavelengths in
  the range of 420 to 500nm

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Design Schedule
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Team Responsibilities

• Bridget Mollner
• Overall Device Design
• Mario Martinez
• Webpage
• Light Source
• Shawna McGehee
• Detection and Imaging

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QUESTIONS?