U.S. patent application number 09/854024 was filed with the patent office on 2002-12-12 for ultrasonic breast examination system.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Hong, Hyundae.
Application Number | 20020188198 09/854024 |
Document ID | / |
Family ID | 25317532 |
Filed Date | 2002-12-12 |
United States Patent
Application |
20020188198 |
Kind Code |
A1 |
Hong, Hyundae |
December 12, 2002 |
ULTRASONIC BREAST EXAMINATION SYSTEM
Abstract
A wearable breast tissue examination device including a support
element adapted to fit over at least a portion of a breast of the
wearer. The support element has a shell, a measurement apparatus
including at least two mutually opposed ultrasound transducer
arrays disposed on at least a portion of the inner surface of the
shell and at least one bladder element disposed in the shell that
is configured to orient the wearer's breast properly for
examination. The wearable device may also include means for
operatively connecting the two mutually opposed transducer arrays
to a transducer driver, and means for holding the support element
on the wearer during use.
Inventors: |
Hong, Hyundae; (West
Chester, OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
|
Family ID: |
25317532 |
Appl. No.: |
09/854024 |
Filed: |
May 11, 2001 |
Current U.S.
Class: |
600/437 |
Current CPC
Class: |
A61B 8/4494 20130101;
Y10S 128/915 20130101; Y10S 128/916 20130101; A61B 8/4227 20130101;
A61B 8/4209 20130101; A61B 8/4281 20130101; A61B 8/0825
20130101 |
Class at
Publication: |
600/437 |
International
Class: |
A61B 008/00 |
Claims
What is claimed is:
1. A breast tissue examination device, at least a portion of which
is adapted to be worn by a wearer, the device comprising: a support
element adapted to fit over at least a portion of a breast of the
wearer, the support element including: a shell having an opening, a
perimeter defined by the opening, an inner surface that faces the
breast of the wearer during use and an outer surface opposed to the
inner surface; a measurement apparatus including at least two
mutually opposed ultrasound transducer arrays, the transducer
arrays being disposed on at least a portion of the inner surface of
the shell; and at least one bladder element disposed adjacent at
least a portion of one of the mutually opposed ultrasound
transducer arrays and/or the inner surface of the shell, the
bladder configured so as to orient the wearer's breast for
examination; means for operatively connecting the two mutually
opposed transducer arrays to a transducer driver; and means for
holding the support element on the wearer during use.
2. The device of claim 1 wherein each of the mutually opposed
ultrasound transducer arrays comprises a multiplicity of ultrasound
transducers.
3. The device of claim 2 wherein the ultrasound transducers are
arranged as opposing pairs of transducers, each opposing pair
comprising a first transducer having a first transducer face and a
second transducer having a second transducer face, wherein the
first transducer face is parallel the second transducer face.
4. The device of claim 1 wherein the transducer arrays are disposed
on a series of concentric ridges disposed on the inner surface of
the shell.
5. The device of claim 1 wherein the transducer arrays each
comprise both ultrasonic transmitting transducers and ultrasonic
receiving transducers.
6. The device of claim 1 wherein one of the transducer arrays
comprises ultrasonic transmitting transducers and the other of the
transducer arrays comprises ultrasonic receiving transducers.
7. The device of claim 1 wherein the transducer arrays are arranged
in a parallel array pattern or a radially symmetric array
pattern.
8. The device of claim 1 wherein the bladder is filled with an
acoustic transmission medium.
9. The device of claim 1 wherein the acoustic transmission medium
includes water, silicone and/or oil.
10. The device of claim 1 wherein the bladder is fillable with an
acoustic transmission medium and the device further includes a
reservoir for holding the acoustic transmission medium when the
acoustic transmission medium is not in the bladder.
11. The device of claim 1 further comprising a cushion deposed
along at least a portion of the perimeter of the shell, the cushion
adapted to form a seal against the wearer during use.
12. The device of claim 1 further including an insert disposed
between the bladder and the wearer's breast during use.
13. The device of claim 1 further including a microprocessor for
processing data generated by the transducers.
14. The device of claim 1 wherein the two mutually opposed
transducer arrays are mounted on opposing ends of a curved
armature.
15. The device of claim 14 wherein the curved armature is rotatable
within the shell.
16. The device of claim 1 wherein the means for holding the support
element on the wearer during use includes a strap.
17. The device of claim 16 wherein the supporting element includes
two shells, and wherein the two shells are joined together such
that the support element forms a brassiere-like structure including
the straps and shells that can be worn by the wearer as a brassiere
is worn.
18. The device of claim 1 wherein the support element includes at
least two bladders.
19. The device of claim 1 wherein at least a portion of the device
is operatively joined to a non-wearable element and wherein the
non-wearable element includes one or more of the following: a
reservoir for holding the acoustically conductive liquid, a
microprocessor and/or a power supply.
20. A device to examine the breast of a wearer, the device
comprising: a) a shell having an opening, a perimeter defined by
the opening, an inner surface that faces the breast of the wearer
during use, an outer surface opposed to the inner surface, and a
bisecting plane dividing the shell into a first half and a second
half; b) a first ultrasonic transducer array disposed adjacent the
inner surface of the shell first half, the array comprising: i) a
plurality of ultrasonic transmitting transducers each having a
transmitting surface, the transmitting surface of the transducers
being aligned perpendicular to the bisecting plane; ii) a means for
electronically controlling the first transducer array; c) a second
ultrasonic transducer array disposed adjacent the inner surface of
the shell second half, the array comprising: i) a plurality of
ultrasonic receiving transducers each having a receiving surface,
the receiving surface of the transducers being aligned
perpendicular to the bisecting plane, each of the receiving
transducer being capable of receiving an ultrasonic signal from at
least one oppositely aligned transmitting transducer; ii) a means
for electronically controlling the second transducer array; d) a
first flexible bladder disposed in at least a portion of the first
half of the shell, the first flexible bladder capable of being
independently and controllably filled with an acoustic transmission
medium, thereby forming a substantially airless seal between the
first transducer array and the wearer's breast; e) a second
flexible bladder disposed in at least a portion of the second half
of the shell, the second flexible bladder capable of being
independently and controllably filled with an acoustic transmission
medium, thereby orienting the wearer's breast and further forming a
substantially airless seal between the second transducer array and
the wearer's breast; and f) an apparatus for originating an
acoustical signal at the transmitting transducers and processing
the signal received by the receiving transducers.
21. The device of claim 20 wherein the first and second ultrasonic
transducer arrays are disposed on a series of concentric ridges
disposed on the inner surface of the shell.
22. The device of claim 20 wherein the transducer arrays are
arranged in a parallel array pattern or a radially symmetric array
pattern.
23. The device of claim 20 wherein the acoustic transmission medium
includes water, silicone and/or oil.
24. The device of claim 20 further comprising a cushion deposed
along at least a portion of the perimeter of the shell, the cushion
adapted to form a seal against the wearer during use.
25. The device of claim 20 further including an insert disposed
between the bladder and the wearer's breast during use.
26. The device of claim 20 further including a microprocessor for
processing signal received by the receiving transducers.
27. The device of claim 20 wherein the two mutually opposed
transducer arrays are mounted on opposing ends of a curved
armature.
28. The device of claim 27 wherein the curved armature is rotatable
within the shell.
29. The device of claim 20 wherein the supporting element includes
two shells, and wherein the two shells are joined together such
that the support element forms a brassiere-like structure which is
held on the wearer by straps.
30. The device of claim 20 wherein at least a portion of the device
is operatively joined to a non-wearable element and wherein the
non-wearable element includes one or more of the following: a
reservoir for holding the acoustically conductive liquid, a
microprocessor and/or a power supply.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a system for examination of
breast tissue, preferably self-examination of breast tissue by
transmitting ultrasonic radiation through the tissue to be
examined. The examination system of the present invention can be
portable and/or wearable and has the advantage of being readily
adaptable for home use as well as being highly accurate.
BACKGROUND OF THE INVENTION
[0002] Breast cancer is a disease that affects many women and men
throughout the world. The death rate for women with breast cancer
in the United States is estimated to exceed one in nine women and
the death rate for un-diagnosed cases is even higher. The high
mortality rates are due to the ease in which this disease can
metastasize through blood vessels and lymph nodes. As with many
types of cancer, it has been found that accurate and early
diagnosis is important to reducing the rate of mortality among
those affected. In most cases, breast self-examination and routine
mammography are the principal means for detecting breast
abnormalities at early stage of malignant development. However, the
cost, discomfort and availability of mammography and the lack of
knowledge about how to perform a proper self-examination reduce the
chances that an individual will be diagnosed with breast cancer
early enough to significantly increase the chances that the
individual will be able to survive the disease. Through many
clinical studies, it is also shown that breast cancer can be
curable if it is found at its early stage when the treatment can be
effective.
[0003] Thus, there is a long felt need for a simple procedure for
breast tissue examination which is non-invasive, and which can be
conducted accurately and in the privacy of a medical office or in
the home. To this same end, there is a need for a tissue
examination system which is capable of accurately detecting
irregularities in tissue density so as to aid medical personnel in
ascertaining whether certain tissues are cancerous, precancerous,
or otherwise benign.
SUMMARY OF THE INVENTION
[0004] The present invention meets the aforementioned need in that
it has been surprisingly discovered that human breast tissue can be
non-invasively examined to accurately determine the presence of
irregularities in tissue density. This non-invasive examination can
be conducted using a device that provides an ultrasonic signature
of the breast tissue by transmitting ultrasonic waves from an
ultrasonic transmitting transducer through the breast to an
ultrasonic receiving transducer. In one embodiment, at least a
portion of the device is wearable and includes a support element
adapted to fit over at least a portion of a breast of the wearer.
The support element includes a shell having an opening, a perimeter
defined by the opening, an inner surface that faces the breast of
the wearer during use and an outer surface opposed to the inner
surface. The support element further includes a measurement
apparatus having at least two mutually opposed ultrasound
transducer arrays, the transducer arrays being disposed on at least
a portion of the inner surface of the shell. Preferably, the
support element also includes at least one bladder element disposed
adjacent at least a portion of one of the mutually opposed
ultrasound transducer arrays and/or the inner surface of the shell,
the bladder configured so as to orient the wearer's breast for
examination. The wearable breast examination device also includes
means for operatively connecting the two mutually opposed
transducer arrays to a transducer driver, and means for holding the
support element on the wearer during use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a front view of one embodiment of the breast
tissue-examining device of the present invention shown on a
user.
[0006] FIG. 2 is the alternative embodiment of the device of the
present invention.
[0007] FIG. 3 is an enlarged, cross sectional view of the shell
portion of the present invention.
[0008] FIG. 4 is an enlarged cross-sectional view of the shell
portion of the present invention shown with the flexible bladder
expanded.
[0009] FIG. 5 depicts a human female breast in an unsupported
position and in a supported position.
[0010] FIG. 6 is a cross-sectional view of a portion of the device
of the present invention, including a reservoir and piston.
[0011] FIG. 7 is an isometric view of one embodiment of the present
invention including straps and insert liners.
[0012] FIG. 8 is an enlarged, cross-sectional view of the shell
portion of the present invention showing two mutually opposed
ultrasound transducer arrays within the shell.
[0013] FIG. 9A shows a plan view of an exemplary terrace
configuration for supporting the transducer arrays within the
shell. The transducers are shown in a parallel array
arrangement.
[0014] FIG. 9B shows a plan view of an exemplary terrace
configuration for supporting the transducer arrays within the
shell. The transducers are shown in a radially symmetrical array
arrangement.
[0015] FIG. 10 is a block diagram of one embodiment of a system
that can be used to trigger a transmitting transducer array and
receive signals from a receiver transducer array.
[0016] FIG. 11 is a graphical representation of the time-domain
profile of an ultrasonic signal.
[0017] FIG. 12 is an enlarged, cross-sectional view of an
alternative embodiment of the present invention including a
rotating armature.
[0018] FIG. 13 shows an exemplary result of an exam representing
the detection of an abnormality in a breast model.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention relates to a device, preferably a
wearable device, for determining the presence of irregular tissue
density. The present invention also relates to a device capable of
providing an accurate location of the irregular tissue density
within the area being examined. In one preferred embodiment, the
device is adapted to examine the breast tissue of a user. The
device can be adapted to examine one or both of the breasts at one
time. Further, the device can be used by a patient at a location
remote from a hospital or a physician's office, such as at home or
a place of business. The information obtained by the device can be
stored, printed or relayed to any suitable location for
diagnosis.
[0020] In one preferred embodiment of the present invention, the
device is at least partially wearable by the user. As used herein,
the term "wearable" refers to devices that are adapted to be worn
by the user throughout at least a period of time during the
examination of the tissue. That is, the size, configuration and
makeup of the device are such that at least a portion of the device
can be placed on the user and held in place thereon for some period
of time during use. An example of a wearable embodiment of the
present invention is shown in FIG. 1. In contrast, non-wearable
devices are not placed on the wearer, but rather that are
freestanding or supported on a table or other structure. Such
non-wearable devices typically require that the user be placed into
the device or positioned next to the device during use. An example
of a non-wearable embodiment of the present invention is shown in
FIG. 2.
[0021] As noted above, FIG. 1 shows one example of a wearable
embodiment of the present invention. The breast examination device
1 includes at least one support element 2 adapted to fit over the
breast 14 of the wearer 3. The support element 2 acts to hold the
breast 14 in a proper position for examination as well as holding
other components of the device 1. The support element 2 may be of
any suitable size and shape and be made from any material suitable
for use in connection with the examination of the wearer's breast
14. In one embodiment, the support element 2 may comprise a
semi-rigid or rigid generally hemispherical shell 4. As can be seen
in FIGS. 1 and 3, in a preferred embodiment, the shell 4 may be
shaped similarly to the cup of a brassiere. Exemplary materials
from which the shell 4 may be formed include plastics, foams (e.g.,
Styrofoam or other semi-rigid or rigid foams), rubbers, wood,
ceramic, metals, silicones and the like.
[0022] The support element(s) 2 of the device 1 may include or be
joined to one or more straps 5. The straps 5, as shown in FIG. 1,
help maintain the support elements 2 in place about the wearer
during use. The straps 5 may be made from any suitable material,
but are preferably non-irritating to the wearer's skin. Exemplary
straps 5 can be made from and configures similarly to the straps of
a brassiere and may be adjustable to fit a range of wearers.
Alternatively, the supporting elements 2 may be held in place by
elastic bands, adhesive, a garment (e.g., a halter top), or any
other known means or combinations thereof. Further, if the device 1
includes two support elements 2, the support elements 2 may be
connected directly or indirectly to each other, such as for
example, by a clasp 6.
[0023] FIG. 3 is a cross-sectional view of an exemplary generally
hemispherical shell 4 having an outer surface 7 and an inner
surface 8. The shell 4 preferably has a perimeter 60 defining the
opening of the shell 4. In certain preferred embodiments, a cushion
11 is disposed adjacent at least a portion of the perimeter 60 of
the shell 4, as shown in FIG. 3. The cushion 11 may act to help
conform the support element 2 to the wearer and to hold it in place
on the wearer during use. The cushion 11 may also be adapted to
provide for an airtight seal against the wearer's body. The cushion
11 may comprise foam, a natural or synthetic rubber, an adhesive
such as a hydrogel adhesive, or any other resilient material
suitable for use against a human body.
[0024] In preferred embodiments of the present invention, the
support element 2 includes at least one bladder 12 (FIG. 4). The
bladder structure 12 preferably creates a comfortable and complete
coupling between a subject's breast 14 and the measurement
apparatus 13 mounted on the inner surface 8 of the shell 4.
Further, the bladder(s) 12 act to properly orient the breast 14 of
the wearer 3 for the examination and to promote proper transmission
between the measurement apparatus 13 and the breast tissue.
Specifically, the bladder(s) 12 lift up the breast 14 and help
ensure that the breast tissue is more uniformly distributed for
scanning by measurement apparatus 13. (FIG. 5 shows an exemplary
human female breast 14 in cross-section shown in a supported
position (solid line) and an unsupported position (dotted line).)
If the breast 14 is not first lifted into a supported position,
wherein the breast tissues are not overlapping or constricted
partially or overall, the outcome of the exam can be susceptible to
non-uniform distribution of breast tissue mass. This can lead to a
reduced ability to detect and locate the exact position of
different density tissue regions that are indicative of abnormal
tissue.
[0025] As shown in FIG. 4, the support element 2 preferably
includes a first bladder 15 disposed adjacent at least a portion of
the inner surface 8 of the shell 4 and a second bladder 16 disposed
adjacent a different portion of the inner surface 8 of the shell 4.
In the embodiment shown in FIG. 4, the first bladder 15 is disposed
adjacent the lower inner surface 9 of the shell 4 and the second
bladder 16 is disposed adjacent the upper inner surface 10 of the
shell 4. (The terms "upper" and "lower" as used herein refer to
relative locations determined when the examination device 1 is
being used and the wearer 3 is seated or standing upright.
Therefore, in this embodiment, the upper bladder 15 is generally
located toward the cranial direction while the lower bladder 16 is
generally located toward the caudate direction). The upper bladder
16 and lower bladder 15 are preferably expanding independently. The
lower bladder 15 is preferably expanded first to lift up the breast
14 to a proper position and then the upper bladder 16 is expanded
to gently compress the breast 14 for efficient coupling with the
breast tissue. FIG. 4 depicts the upper and lower bladders 15, 16
in a filled, inflated state.
[0026] Of course, any number of bladders 12 can be used and the
location of the bladders in the support element 2 can be varied.
Further, each bladder 12 can include any number of internal cells
or chambers that can be filled together or independently with the
same or different materials. In any case, it is generally preferred
that regardless of the arrangement, the bladders 12 be configured
to expel substantially all of the air from around the breast 14
such that the bladder 12 is in intimate contact with the surface of
breast 14. In certain embodiments, all or a portion of the bladder
12 may be covered with another material or part of the breast
examination device 1 such that the bladder 12 itself is not in
contact with the breast tissue, but rather the other material or
part of the device 1 is in direct contact with the breast tissue
once the air is expelled by the bladder(s) 12. In some
circumstances, it may be desirable to apply a material, such as an
acoustic coupling medium 17 between at least a portion of the
bladder 12 and the breast skin to help maintain an airtight seal
between the bladder 12 and the breast tissue. Preferably, the
material that is applied between the bladder 12 and breast tissue
to help maintain the seal is generally acoustically transparent so
as not to distort or negatively affect the results of the
examination.
[0027] In embodiments wherein the measurement apparatus 13 includes
an ultrasonic transducer, the bladders 12 are preferably filled
with an acoustic transmission medium 18. The acoustic transmission
medium 18 preferably transmits ultrasonic waves with attenuation
similar to normal human female breast tissue. The function of the
acoustic transmission medium 18 is to deliver ultrasonic waves to
the breast tissue being examined with minimum attenuation along the
path through bladder 12 and acoustic coupling medium 17. The
bladders 12 can be filled with any suitable acoustically conductive
or transparent material. As used herein the terms "acoustically
conductive" and "acoustically transparent" are used herein to mean
any material that does not significantly alter the transmission or
affect the reception of a particular predetermined ultrasonic
signal. Non-limiting examples of suitable acoustic transmission
media include water, silicones such as silicone oils, polyurethane,
bio-grade saline and the like.
[0028] The bladder(s) 12 may be pre-filled or fillable upon use. If
the bladders are not pre-filled, the bladders 12 may be filled via
a bladder filling mechanism 19, one example of which is shown in
FIG. 6. The bladder filling mechanism 19 may include a reservoir 20
including the acoustic transmission medium 18. The bladder filling
mechanism 19 including the reservoir 18 may be a part of the
wearable or non-wearable portion of the device 1 or may be a
separate device, such as a handheld fluid containing bulb or
syringe, to be used in conjunction with the examination device 1.
The bladder filling mechanism 19 may include any mechanism known in
the art to transport a liquid or semi-liquid material, including
hand pumps, positive displacement pumps, rotary pumps, syringes,
and the like. In one exemplary embodiment, as shown in FIG. 6, the
bladder filling mechanism 19 includes an actuator 21 that moves a
plunger 22 to change the volume of the acoustic transmission medium
18 in the bladder 12. When the actuator 21 pushes the plunger 22 to
expand the bladder(s), the bladder 12 conforms to the breast 14
being examined (e.g. FIG. 4). One exemplary bladder filling
mechanism 19 includes at least one electric motor and at least one
driver integrated circuit, such as the Motorola MC33192 Stepping
Motor Controller that controls the actuator 21 and moves the
plunger(s) 22 to fill the bladders.
[0029] Regardless of the bladder filling mechanism 19 employed, the
pressure level within the bladders 12 may affect breast comfort and
the quality of the acoustic coupling between the breast 14 and the
bladders 12 and/or other portions of the device 1. Therefore, in a
preferred embodiment of the present invention, the bladder(s) 12
may be controlled so as to provide the desired benefits (e.g.
support, minimizing acoustic attenuation, etc.) while providing
reasonable comfort to the wearer. The wearer 3, the caregiver or
any other persons involved in the examination, may manually control
the bladder(s) 12. Alternatively, the bladders 12 may be controlled
by a microprocessor or any electronic controller means or mechanism
capable of affecting the expansion of the bladder(s) 12. In any
case, the controller or controlling mechanism may affect the rate
of expansion of the bladder(s) 12, the pressure exerted by the
bladder(s) 12 on the breast 14 and/or the final configuration of
the bladder(s).
[0030] The bladder filling mechanism 19 may include a pressure
sensor 23 to help the user, wearer 3 and/or a microprocessor to
monitor the pressure in the bladder 12. The information provided by
the sensor 23 can be used to adjust the pressure in the bladder
and/or the rate of filling or emptying of the bladder 12. In
general, a pressure in the bladder 12 of between about 0.1 psi and
about 5 psi is suitable for examination of human breast tissue.
However, different pressure levels may be more suitable for
different cup sizes, or different breast parenchyma (breast tissue
mass). A filling rate generating pressure increases of between
about 0.2 psi/sec and about 0.5 psi/sec are generally suitable to
ensure reasonable comfort to the wearer, although other rates are
possible.
[0031] As noted above, in certain preferred embodiments of the
present invention, an acoustic coupling medium 17 may be applied to
the interface between the bladder 12 and the breast skin. The
acoustic coupling medium 17 facilitates the transmission of
ultrasonic signals across the boundary between the breast skin and
the bladder 12, ensuring that minimal attenuation of the signal
occurs. The acoustic coupling medium 17 may be applied to the
breast skin or the bladder surface and may comprise any known
material capable of transmitting ultrasonic waves. Exemplary
materials include water, hydrogels, silicones, polyurethanes, and
the like. The acoustic coupling medium 17 may be applied in any
form, but is preferably a liquid, semi-solid, gel, or paste
form.
[0032] In certain preferred embodiments, as shown in FIG. 7, the
acoustic coupling medium 17 may be disposed on an insert liner 24
that can be placed between the bladder and the breast. The insert
liner 24 may be similar to a regular bra cup or breast pad and may
be available for different cup sizes. The insert liner 24 may be
made from or have disposed thereon the acoustic coupling medium 17.
The insert liner 24 may be reusable or disposable and may comprise
materials suitable for use with the device of the present
invention. In one exemplary embodiment, the liner 24 may comprise a
hydrogel or cellulose fiber which is wetted prior to examination,
such as CMC fiber available from Acordis Specialty Fibers of
Coventry, UK disposed on a support substrate such as a nonwoven,
film, foam, tissue, etc. The liner 24 may additionally comprise an
adhesive such as a pressure sensitive or water activatable adhesive
to help keep the liner 24 in place during use.
[0033] The breast examination device 1 of the present invention
additionally comprises at least two mutually opposed ultrasound
transducer arrays, such as the first transducer array 25 and second
transducer array 26 shown in FIG. 8. By "mutually opposed" it is
meant that the transducer arrays are aligned in a facing
configuration such that an ultrasonic pulse from a transmitting
transducer in the first transducer array 25 is received by a
receiving transducer in the second transducer array 26 (or
vice-versa) after the pulse has passed through the intervening
breast tissue. Therefore, as shown in FIG. 8, in one preferred
embodiment, the first transducer array 25 includes a transducer 28
having a first transducer face or transmitting surface 65 and the
second transducer array 26 includes a transducer 28 having a second
transducer face or receiving surface 67 which is opposed to the
transmitting surface 65 and generally parallel thereto. The
mutually opposed transducer pairs may also be configured in a
parallel array pattern, as is shown in FIG. 9A. In such
embodiments, the signal of the transmitting transducer (represented
by line 100) intersects plane 27 that bisects the shell 4 at an
angle of about 90 degrees. FIG. 9A shows an exemplary embodiment of
the parallel array pattern, as it would appear in plan view looking
into the shell 4 toward the inner surface 8. As can be seen, the
ultrasonic waves (represented by the number 100 ) propagate in a
direction generally perpendicular to the bisecting plane 27. This
is due to the transducers being disposed along the annulus of the
concentric rings 30 shown in FIG. 9A with the faces of the
transducers parallel to the bisecting plane 27. The resulting image
from data generated by transducers in this configuration can be
similar to that of a cranial-caudate image from mammography.
[0034] In an alternative embodiment the transducers may be arranged
in a radially symmetrical array pattern, as is shown in FIG. 9B.
Preferably, the transducers in such a pattern are arranged to cover
surround substantially the entire perimeter of the breast. In such
embodiments, the transducers 28 are installed along the perimeter
of at least one ring 30 in mutually opposed transmitter and
receiver pairs. The mutually opposed pairs face each other, but are
not necessarily oriented in any particular way with respect to the
bisecting plane 27. Rather, the mutually opposed pairs are disposed
within the shell so as to be located along the perimeter of annulus
of the concentric ring(s) 30. Therefore, as shown in FIG. 9B, the
ultrasonic waves 100 from each of the mutually opposed pairs of
transducers are directed at different angles to the bisecting plane
27. However, each of the waves 100 passes generally through the
centerpoint 110 of the shell 4. In such embodiments, the results
can provide the user with tomographic images similar to those that
are obtained from computerized tomography or magnetic resonance
imaging. One example of an output that can be obtained from such a
system is shown in FIG. 13.
[0035] Each transducer array may include one or more transducers.
Preferably, each transducer array may comprise a multiplicity of
transducers 28 which, as shown in the embodiment depicted in FIG.
8, may be mounted on terraces 29 formed on the inner surface 8 of
the shell 4 so as to align the first and second transducer arrays
in a mutually opposed configuration. In one embodiment, as shown in
FIG. 9, the terraces 29 form concentric rings 30 extending
throughout the inner surface 8 of the shell 4. However, embodiments
are contemplated wherein the terraces 29 are disposed on only a
portion of the inner surface 8 of the shell 4, and/or are somewhat
irregularly arranged within the shell 4. The transducers 28 may be
joined to the terraces 29 by any known means, including, for
example, an epoxy glue such as Loctite.RTM. 330
adhesive-elastometric, Rocky Hill, Conn.
[0036] The number of rows of transducers 28 as well as the total
number of transducers 28 may vary based on the size of the device 1
and/or the size of the subject's breasts. In any case, it is
preferred that enough transducers 28 are used such that the entire
area of examination (e.g. width and height of the breast) is
surrounded by transducers. In one exemplary embodiment each
transducer array may include several hundred transducers in order
to sufficiently surround the breast. Table 1, below lists a few
non-limiting examples of the number of transducers and the number
of rows of transducers that have been found to be suitable for use
with the device of the present invention in various standard bra
cup sizes, assuming 7.5 mm diameter transducers are employed.
1TABLE 1 Bra Cup Size Rows of Transducers Number of Transducers A 7
43 B 8 50 C 9 57 D 11 71
[0037] The ultrasound transducer array preferably comprises
ultrasonic transducers sufficiently small so as to maximize the
spatial resolution of the array, but not so small as to increase
ultrasound beam diameter within the breast tissue because such an
increase can lead to poor resolution. The device preferably detects
tissue abnormalities in the breast as small as 5 mm in diameter.
Thus, it has been found that transducers having a diameter of
between about 5 mm and about 10 mm are generally suitable for such
detection, although other size transducers may certainly be used.
In some cases, it may be desirable to provide the transducer with
focusing lenses to help form the signal from the transducer. The
transducers 28 may also operate at any suitable frequency, although
a frequency between about 1 MHz and about 10 MHz has been found to
be highly effective for examining human breast tissue in terms of
low attenuation and high spatial resolution.
[0038] The transducers 28 may be triggered all together, in groups
or individually. In preferred embodiments, the transducers 28 are
triggered individually and sequentially to reduce a multiple beam
overlapping and thus, so more readily pinpoint the exact location
of any abnormality in the tissue. In order to improve the
resolution of the system, it may also be desirable to configure the
device 1 such that transmitting transducers and receiving
transducers are alternately arrayed on opposing sides of the
breast. This allows for signals to be sent through the tissue in
both directions. Alternatively, transducers 28 may be employed that
are capable of both sending and receiving signals.
[0039] As noted above, the transducers 28 are preferably activated
once the bladder pressure reaches a predetermined level.
Preferably, the transducer driver 31 triggers each transducer 28 in
the transmission array individually and in sequence to produce an
ultrasonic pulse directed through the breast tissue and toward the
paired receiving transducer. In preferred embodiments, some time
delay is provided between each ultrasonic pulse to allow the
ultrasonic noise to subside below a threshold level. This method is
called time gating. Time gating can help reduce undesirable noise
in the signals and help ensure that signals indicative of tissue
abnormalities are discernable. It has been found that a suitable
time between pulses can be between about 1 ms and about 100 ms. The
pulse duration is preferably in the range of about 100 nanoseconds
to about 500 nanoseconds.
[0040] Exemplary suitable ultrasound transducers are available as
videoscan immersion type transducers, V303-SU-F1 type from
Panametrics Inc. of Waltham, Mass.; piezocomposite transducers from
MSI of Littleton, Mass.; and APC 850 type transducers from American
Piezo Ceramics (Mackeyville, Pa.). Alternatively, MEMS (Micro
Electro Mechanical System) based ultrasound transducers can be used
to improve spatial resolution within a limited space. As an
example, a suitable MEMS based capacitive ultrasound transducer is
available as L-STD-1 from the Sensant Corporation of San Leandro,
Calif. (U.S. Pat. Nos. 5,619,476, 5,870,351, 5,894,452, 5,982,709).
Since the MEMS transducers are very small, a greater number of them
may be used in a relatively closer spacing, resulting in an
improvement in resolution, allowing the detection of smaller tissue
abnormalities. Thus, such transducers are advantageous for several
reasons, including their small size, low profile, high sensitivity,
and wide frequency range.
[0041] The transducers 28 of the present invention are preferably
driven by a transducer driver 31, a simple exemplary block diagram
of which is shown in FIG. 10. The transducer driver 31 may be a
separate element that is operatively connected to the wearable
portion or may be an integral part of the wearable portion of the
device 1. If the transducer driver 31 is a separate element, the
transducer driver 31 may be housed in a container such as housing
32 shown in FIG. 1. This configuration allows the wearable portion
of the device 1 to be lighter in weight and more conformable to the
shape of the wearer.
[0042] As shown in FIG. 10, the transducer driver 31 may include an
on-board microprocessor 36, switching control circuitry adapted to
deliver a high voltage pulse 33, and high voltage pulse source 34
to trigger ultrasound transducers 28. In embodiments wherein the
transmitting transducer array 25 is operating in pulse mode, the
ultrasound transducers 28 may be activated by a high voltage spike.
The high voltage spike is generated from the high voltage source 34
that may include a high voltage dc source and a capacitor. At the
direction of the microprocessor 36 and switching control circuitry
33, high voltage stored in the capacitor is discharged and
delivered to the transducers to trigger an ultrasound pulse. This
triggering pulse typically has a falling edge of a voltage spike.
It has been found that a suitable amplitude of such a spike can be
in the range of about 360 and about 400 volts, but other amplitudes
are contemplated and may be preferred for other uses or with
different equipment. In such embodiments, the pulse duration is
preferably in the range of about 100 nanoseconds to about 500
nanoseconds. Although not limited to the following, it has been
found that the total electrical power delivered to each transducer
may be between about 12 Watts and about 16 Watts if the transducer
has 10 k ohm resonance impedance. Accordingly, it has been found
that the total energy delivered may be between about 1.3 micro
Joules and about 8 micro Joules.
[0043] In the embodiment shown in FIG. 10, the microprocessor 36
sets the address of the individual transducer 28 that should be
triggered within the array 25 and sends it to the switching control
33. The switching control circuitry has a direct hardware
connection to both high voltage source 34 and transducer array 25.
Switching control circuitry 33 preferably includes a programmable
gate array such as an FPGA (Field Programmable Gate Array) for
address decoding and command interfacing between the microprocessor
36 and the switching circuitry 33. It is also preferable that the
switching circuitry 33 includes a high voltage switching transistor
or similarly functioning semiconductor switching array so that upon
the receipt of discharge enable signal from microprocessor, it
discharges high voltage stored at high voltage pulse generator
34.
[0044] Once triggered, the transducer 28 generates ultrasonic waves
100 by vibration (e.g. axial vibration of a piezioceramic
transducer). After passing through the breast tissue and coupling
structure, the waves 100 arrive at the receiving transducer array
26. The receiving transducers convert the ultrasonic waves 100 into
an electrical signal which is eventually stored in memory. In some
embodiments, all of the transducers 28 within the receiving array
26 can be operated at the same time, and thus, more than one
receiving transducer may detect the ultrasonic waves from the
transmitting transducer. However, in such embodiments, the signal
switch 35 can select the specific receiving transducer matched with
its corresponding transmitting transducer with information relating
to the addresses of the transducers from microprocessor 36. In
other embodiments, only the receiving transducer that is matched
with the transmitting transducer is operated at the time the
transmitting transducer is signaled. In either case, there is
preferably a one-to-one correspondence of each transducer pair of
transmitting and receiving arrays 25, 26.
[0045] The microprocessor 36 may be used to save and/or process the
signals generated and/or received by the transducer 28 in any way
desired by the user. For example, the operating program run by the
microprocessor 36 can be written to detect a drop (depending on the
tissue density) in the ultrasound transmission power compared to
neighboring tissue, (Any sudden or abrupt changes in the peak
amplitude profile may indicate a potentially abnormal tissue
structure, which could be indicative of a hard mass or tumor.) In
one embodiment, a drop of at least about 30% has been found to be
suitable for detection of hard masses and/or tumors in human breast
tissue.
[0046] The microprocessor 36 may also be programmed to check the
time-of-flight (TOF) for each detected signal. The TOF represented
by the number 47 is defined as a time interval from the time the
transmitting transducer is triggered to the moment the signal is
received at the corresponding receiving transducer. As an example,
FIG. 11 shows the time-domain profile of the transmitted ultrasound
signal. In the plot of FIG. 11, the total transmission TOF is the
time indicated by the number 47. The transducer triggering signal
is indicated by the number 48 and the arrival of the transmitted
signal is indicated by the number 49. Monitoring the TOF can also
help determine the nature of the abnormality (e.g., cyst or hard
mass). For example, a shorter TOF or higher transmission speed of
ultrasound waves, compared to the surrounding tissue under
examination generally indicates a harder or denser inclusion in the
breast tissue. In embodiments where the transmitting and receiving
ultrasonic transducer pairs may have different separation
distances, the microprocessor 36 may also run a program to
compensate for the different degree of signal attenuation due to
non-uniform path lengths of the ultrasound signals.
[0047] The microprocessor 36 can be any suitable microprocessor
such as Texas Instruments TMS320C1X series, the Motorola DSP5600
series, the Analog Devices ADSP-218X series, the Lucent
Technologies ADSP32C series. The microprocessor 36 may be part of
the transducer driver 31 or a separate device. Further, the
microprocessor 36 and its supporting electronics may be integral
with the wearable portion of the examination device 1 or may be a
separate element operatively connected to the device 1. For
example, the microprocessor 36 may be located in the housing 32 and
joined to the support element 2 by wires. Alternatively, the
microprocessor 32 can be remotely located from the examination
device 1 (e.g. different room or building) and connected to the
examination device 1 by wires, by radio (RF) waves or light waves
(IR), depending on the environment in which the device 1 is
used.
[0048] The examination device 1 may also include a data port
adapted to transmit the data or diagnosis to a physician, computer,
or website. Suitable data ports include telephone jacks, USB ports,
serial ports, parallel ports, infrared or radio frequency
transmitters, and the like.
[0049] The power supply for the examination device 1 or any portion
of the device 1 may be any power supply known in the art suitable
for such use. The power source may be a standard AC wall power or a
battery. However, for wearable embodiments of the present
invention, it is generally preferred that the device be powered via
a battery which may be disposable or rechargeable.
[0050] In an alternative embodiment of the present invention, as
shown in FIG. 12, the transducers 28 are mounted on a curved
armature 41, which is disposed within the shell 4. The armature 41
preferably includes two oppositely installed arms 42 and 43 having
transducers 28 disposed thereon such that the faces of the
transducers on the first arm 42 of the armature 41 are oriented
towards the faces of the transducers 28 on the second arm 43 of the
armature 41. The armature 41 is adapted to rotate in discrete steps
about the wearer's breast in order to scan the breast from
different angles. In a preferred embodiment, the armature 41 is
capable or rotating completely about the breast to scan the breast
from all angles, however, a lesser amount of rotation is possible
to still give acceptable results.
[0051] As shown in FIG. 12, a motor 44 or other means for rotating
the armature 41 is provided. The motor 44 may be located in the
shell 4 or in a structure joined to the shell 4. Alternatively, the
motor 44 can be located remotely from the shell and joined
therewith via a flexible shaft, belt gear or other means for
connecting the motor 44 to the armature 41. For example, a flexible
drive shaft, such as a Ready-Flex shaft available from S.S. White,
Piscataway, N.J. can be connected to the motor 44 to drive the
armature 41.
[0052] Preferably, the motor 44 is relatively small compared to the
examination device 1, but provides enough high torque to drive the
armature 41 with transducers 28. One example of a suitable motor is
the 512 CPR motor form MicroMo Electronics of Clearwater, Fla.
[0053] It is also preferred that the motor 44 has a position
encoder 45 on the motor shaft 46, so the microprocessor 36 can
determine the angular position of the armature 41 during scanning.
The microprocessor 36 preferably reads the position encoder signal
representing the angular increment. The angular position and
transducer position along the curved armature 41 can be used to
determine the spatial coordinate of any particular transducer
position. This information, in turn, can be used to determine in
which memory location the current ultrasound transmission data will
be saved, facilitating the calculation of the exact location of the
abnormality within the breast.
[0054] In general, an embodiment including a curved, rotating
armature requires fewer transducers 28 in the first and second
transducer arrays 25 and 26 than the stationary embodiments shown
in FIG. 4 because the transducers 28 on the armature 41 are rotated
about the breast rather than having to surround the breast. Thus,
for example, a single column of transducers may be rotated about
the breast to examine from almost any angle. However, the number of
rows of transducers 28 located on the armature 41 may be the same
or similar to preferred number of rows described with respect to
the stationary array embodiment, above. Further, the rotating
curvature embodiment can provide a tomographic rendering of the
ultrasound transmission profile similar to the stationary radially
symmetrical transducer array embodiment shown in FIG. 9B. However,
the output may be derived from a smaller number of transducers 28.
This can reduce the cost of the device as well as the weight of the
wearable portion.
[0055] Preferably, as shown in FIG. 12, the armature 41 is rotated
in one direction in a series of discrete steps through at least 180
degrees of arc to cover entire volume of breast tissue. The steps
may be measured in terms of angle of rotation or actual arc path
length at the transducer position. The steps may vary in size based
on the size of the breast and the minimum size of the inclusion to
be detected (i.e., the resolution). For example, in order to detect
a 5 mm diameter inclusion wherein the distance between the
transmitting and receiving transducer arrays is about 130 mm, each
scanning angular increment is approximately 4.5 degrees of
rotation. After the armature 41 moved a discrete angular increment
(i.e., step), each transmitting transducer 28 in the transducer
array on the armature 41 is preferably triggered in series until
all of the transmitting transducers have been triggered. Once this
is done, the armature 41 preferably moves to the next predetermined
location and the transducers 28 are triggered again. The size and
frequency of the transmitters can be similar to those described in
the stationary embodiment. Further, the same time gating 40 can be
utilized to improve the efficacy of the results obtained from the
examination.
[0056] In embodiments of the present invention wherein the
transducers are configured to provide radially symmetrical
transmission paths, (e.g. the curved armature embodiment and the
stationary embodiment of FIG. 9B), the tomographic transmission
profile of breast tissue may be obtained. One example of a
cross-sectional image made from the data obtained from an
embodiment of the present invention employing radially symmetrical
transmission paths is shown in FIG. 13. The shading pattern in the
result shows relative variation in the ultrasound transmission
profile. The dark shaded area 50 in the middle indicates local drop
in the transmission that would be indicative of a tissue
abnormality. The cross-sectional transmission profiles generated
from the transducer pairs of embodiments employing radially
symmetrical transmission paths can be combined to render a
three-dimensional tomographic transmission profile of the
tissue.
[0057] While particular embodiments and/or individual features of
the present invention have been illustrated and described, it would
be obvious to those skilled in the art that various other changes
and modifications can be made without departing from the spirit and
scope of the invention. Further, it should be apparent that all
combinations of such embodiments and features are possible and can
result in preferred executions of the invention. Therefore, the
appended claims are intended to cover all such changes and
modifications that are within the scope of this invention.
* * * * *