**BLOOD CLOT NONINVASIVE DESTRUCTION USING**

**FOCUSED MODULATED HIGH POWER ULTRASOUND (FMPUL)**

Dr. Yoseph Bar-Cohen, JPL, 818-354-2610, yosi@jpl.nasa.gov

Dr. Robert Siegel, CSMC, 310-855-3849,siegel@csmc.edu

Willem Grandia, 714-631-7672, wgrandia@aol.com

**BACKGROUND**

FMPUL is a system that is currently under development jointly by the Jet
Propulsion Lab (JPL), Cedars-Sinai Medical Center (CSMC) and Quality
Materials Inspection (QMI). FMPUL (patent pending) is being designed to
become a medical tool for noninvasive destruction of blood clots at
confined areas. The potential commercial application of FMPUL is
enormous and could become a standard equipment of every health care
facility.

The FMPUL system employs high power ultrasound at a level that
cyclically produce cavitation bubbles and implosively collapsing them to
damage clots. In general, the lower the ultrasound frequency the larger
and more powerful the cavitation bubbles however, due to diffraction
limits, the focus diameter becomes larger. Our FMPUL technology is aimed
to overcoming this limitation by producing large cavitation bubbles
(typical to low frequencies) at a small focal area (typical to high
frequencies). This technology is the subject of an STTR proposal that we
recently submitted to NIH where we are trying to prove the following
hypotheses:

1.  Focused Modulated low and high frequencies ultrasound will produce
    large cavitation bubbles only at the focal zone of the high
    frequency.

2.  In-vitro application of FMPUL will effectively destroy blood clots
    at the focus that is defined by the high frequency component of the
    ultrasonic wave.

3.  In-vivo application of FMPUL will cause minimum collateral damage to
    normal tissues.

**PROGRESS**

We developed an electronic breadboard that allows inducing
simultaneously two signals with frequencies in the range from 10 KHz to
at least 10 MHz range. A photographic view of the drive breadboard is
shown in Figure 1. ![](media/image1.emf){width="3.9583333333333335in"
height="2.634027777777778in"}

Figure 1: A photographic view of the FMPUL dual frequency drive
electronic breadboard.

To induce the necessary two frequencies, a 10 cm diameter piezoelectric
lens was produced which exhibits resonance at the approximate levels of
20KHz, 250KHz and 750KHz. Preliminary results have been encouraging with
regards to the ability to produce cavitation and introducing
simultaneous signals at the low and high KHz frequency range. In Figure
2a, A schematic view is shown of the lens and the effect that was
observed on the surface of the water tank (in which the lens was
immersed). In Figure 2b, a photographic view is given in angle towards
the water column that is formed by the FMPUL breadboard.

![](media/image2.emf){width="2.7402777777777776in" height="3.7in"}

  ------------------------------------------ ----------------------------
  Figure 2a: A schematic view of the FMPUL   Figure 2b: A photographic
  lens and the observed effect.              view of the FMPUL lens and
                                             the water column that is
                                             formed.

  ------------------------------------------ ----------------------------

January 30, 1997.