Laser and acoustic lens for lithotripsy

Patent · Tue Jan 01 04:00:00 EST 2002

OSTI ID:874928

Visuri, Steven R ^[1]; Makarewicz, Anthony J ^[2]; London, Richard A ^[3]; Benett, William J ^[1]; Krulevitch, Peter ^[4]; Da Silva, Luiz B ^[4]

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1. Livermore, CA
2. San Ramon, CA
3. Orinda, CA
4. Pleasanton, CA

An acoustic focusing device whose acoustic waves are generated by laser radiation through an optical fiber. The acoustic energy is capable of efficient destruction of renal and biliary calculi and deliverable to the site of the calculi via an endoscopic procedure. The device includes a transducer tip attached to the distal end of an optical fiber through which laser energy is directed. The transducer tip encapsulates an exogenous absorbing dye. Under proper irradiation conditions (high absorbed energy density, short pulse duration) a stress wave is produced via thermoelastic expansion of the absorber for the destruction of the calculi. The transducer tip can be configured into an acoustic lens such that the transmitted acoustic wave is shaped or focused. Also, compressive stress waves can be reflected off a high density/low density interface to invert the compressive wave into a tensile stress wave, and tensile stresses may be more effective in some instances in disrupting material as most materials are weaker in tension than compression. Estimations indicate that stress amplitudes provided by this device can be magnified more than 100 times, greatly improving the efficiency of optical energy for targeted material destruction.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• DOE Contract Number: W-7405-ENG-48
• Assignee: The Regents of the University of California (Oakland, CA)
• Patent Number(s): US 6491685
• OSTI ID: 874928
• Country of Publication: United States
• Language: English

Related Subjects

/606/
100
absorbed
absorber
absorbing
acoustic
acoustic wave
amplitudes
attached
biliary
calculi
capable
compression
compressive
compressive stress
conditions
configured
deliverable
density
densitylow
destruction
device
directed
disrupting
distal
duration
dye
effective
efficiency
efficient
encapsulates
endoscopic
energy
estimations
exogenous
expansion
fiber
focused
focusing
generated
greatly
improving
indicate
instances
interface
invert
irradiation
laser
laser radiation
lens
lithotripsy
magnified
material
materials
optical
optical fiber
procedure
produced
proper
provided
pulse
radiation
reflected
renal
shaped
site
stress
stresses
targeted
tensile
tension
thermoelastic
times
tip
transducer
transmitted
via
wave
waves
weaker