U.S. patent application number 11/895610 was filed with the patent office on 2008-12-11 for finger mounted imaging and sensing assembly.
Invention is credited to Kenneth N. Bates, Scott S. Corbett, III, Albert H. Krause, William McDonough, Ronald W. Schutz.
Application Number | 20080306387 11/895610 |
Document ID | / |
Family ID | 40089046 |
Filed Date | 2008-12-11 |
United States Patent
Application |
20080306387 |
Kind Code |
A1 |
Schutz; Ronald W. ; et
al. |
December 11, 2008 |
Finger mounted imaging and sensing assembly
Abstract
An ultrasound finger probe having a finger clip that is adapted
to be mounted on a human finger and an ultrasound probe that is
supported by the finger clip. Also, control input elements are
mounted on the finger clip and are adapted to control the operation
of the ultrasound probe.
Inventors: |
Schutz; Ronald W.;
(Portland, OR) ; Corbett, III; Scott S.;
(Portland, OR) ; Bates; Kenneth N.; (Beaverton,
OR) ; McDonough; William; (Portland, OR) ;
Krause; Albert H.; (Vancouver, WA) |
Correspondence
Address: |
Timothy E Siegel Patent Law, PLLC
601 108th Avenue, Suite 1900
Bellevue
WA
98004
US
|
Family ID: |
40089046 |
Appl. No.: |
11/895610 |
Filed: |
August 23, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60923323 |
Apr 13, 2007 |
|
|
|
Current U.S.
Class: |
600/459 |
Current CPC
Class: |
A61B 8/4472 20130101;
A61B 5/6826 20130101; A61B 90/53 20160201; A61B 5/6838 20130101;
A61B 8/4488 20130101; A61B 8/12 20130101; A61B 8/4209 20130101;
A61B 8/4227 20130101 |
Class at
Publication: |
600/459 |
International
Class: |
A61B 8/14 20060101
A61B008/14 |
Claims
1. An ultrasound finger probe assembly, comprising: a) a
connector-half; b) a multi-conductor cable, electrically connected
to said connector-half; c) a finger clip, adapted to be mounted on
a human finger; and d) an ultrasound finger probe supported by said
finger clip and including elements adapted to provide therapeutic
ultrasound; and e) wherein said multi-conductor cable includes some
traces having a larger cross section than others of said traces,
said larger cross section traces being adapted to provide
electricity for said therapeutic ultrasound elements.
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. An ultrasound finger probe assembly, comprising: a) a finger
clip, adapted to be mounted on a human finger; b) an ultrasound
probe, supported by said finger clip; c) an optical viewing device,
physically associated to said ultrasound probe; and d) a cable
connected to said ultrasound probe and optical viewing device and
adapted to transmit data from said ultrasound probe and optical
viewing device to a further device.
7. The assembly of claim 6, wherein said optical viewing device is
a lens connected to an optical fiber and said cable includes an
optical fiber to transmit data from said optical viewing device to
said further device.
8. The assembly of claim 6, wherein said optical viewing device is
a camera and said cable includes an electrically conductive link
for transmitting said data from said optical viewing device.
9. The assembly of claim 6, further including an illumination probe
physically associated to said optical viewing device.
10. An ultrasound probe assembly, comprising: a) a finger-mounted
ultrasound imaging probe; and b) a sensor physically associated to
said ultrasound imaging probe.
11. The assembly of claim 10, wherein said sensor is a
thermometer.
12. The assembly of claim 10, wherein said sensor is an
oximeter.
13. The assembly of claim 10, wherein said sensor is a
glucometer.
14. The assembly of claim 10, wherein said sensor is a pressure
sensor.
Description
RELATED APPLICATIONS
[0001] This application claims priority from application Ser. No.
60/923,323 filed Apr. 13, 2007, from application Ser. No.
60/861,319 filed Nov. 27, 2006 and from application Ser. No.
10/863,644 filed Jun. 8, 2004, all of which are incorporated by
reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] During a surgical procedure the timely acquisition of
ultrasound imagery can mean the difference between life and death
for the patient. Many devices and techniques have been developed or
suggested to facilitate the speedy acquisition of ultrasound data,
including laparoscopic ultrasound probes, finger mounted probes and
hand-held probes having the ability to wirelessly transmit image
data. Unfortunately, a number of problems continue to hamper
medical personnel in the use of these devices.
[0003] For a hand held probe, users must take an extra mental step
to remember and account for the distance between the position of
the sensor head and the position of the user's hand. Frequently,
the user is required to perform many mental tasks simultaneously,
such as reviewing imagery; manipulating the probe to effect
delicate changes in the probe pressure and angle; and accessing a
bank of medical knowledge in an effort to diagnose a medical
problem. During the stress of a medical procedure the task of
mentally calculating the probe position and orientation, based on
knowledge of the probe geometry, is an extra task that taxes the
already highly-taxed mental resources of the medical professional.
In addition, the extra displacement of the hand from the target
probe head position reduces the ability to utilize muscle memory
for probe positioning.
[0004] Another problem is the disassociation, both in time and
location, of the tactile input that a medical professional receives
from his fingers, during a procedure, and the ultrasound imagery
data. For example, for situations in which a medical procedure must
be interrupted for imaging to occur, it may be quite difficult for
the surgeon to match the tactile information that he notes with the
imagery previously acquired. In diagnostic procedures, it may be
impossible for the medical professional to gain both tactile
information and image information simultaneously. The task of
remembering and piecing together the two types of data presents an
additional challenge to the medical professional.
[0005] Yet another problem encountered by users of currently
available probes is the difficulty in fitting a probe into a small
area. The human body is largely composed of delicate tissue, and
the object of the medical professional is often to address a
localized medical problem while disturbing surrounding or
intervening tissue as little as possible. For example, one type of
desired imagery that is currently very difficult to acquire is
imagery from the posterior of the heart. Hand held probes and/or
probes having a large cross-section present a particular difficulty
when it is desirable to move the probe head through body tissue in
order to obtain imagery of interest.
[0006] Still another issue presented by currently available probes
is the awkwardness of use, as the probe is typically tethered by a
multi-conductor coaxial cable that is one to three meters long, to
an imaging station. It is typically difficult to twist this cable,
so rotating the probe about its longitudinal axis may prove
difficult. In addition, the heavy weight of the cable and need to
grip the probe handle have the potential to create repetitive
motion injuries to sonographers and physicians who use the
ultrasound probe.
[0007] Moreover, many of the tools available for imaging the
internal regions of the human body may be unavailable in a
particular case, due to special conditions. For example, although
trans-esophageal imaging is an extremely valuable tool for cardiac
surgeons, there are instances in which the esophagus is diseased,
making it potentially harmful to insert a probe into the esophagus.
In these situations, having some other method of imaging would be
invaluable.
[0008] A problem faced specifically by cardiothoracic surgeons is
that of assessing plaque deposits in a portion of the aortal arch
and ascending aorta prior to accessing the portion of the aorta. If
there are plaque deposits in the part of the aorta accessed, the
deposit or a portion of it may break off, travel through the blood
stream and lodge in a blood vessel, causing great damage to tissue
that is dependent on the vessel for its blood supply. Although
Doppler ultrasound probes are currently used for the assessment of
plaque deposits in the aortal arch and ascending aorta, currently
available intra-operative probes are about 10 cm long and rigid,
for accessing interior portions of the body. Although this is
potentially useful in some situations, it greatly complicates the
task of successfully placing the probe for imaging a blood vessel
and as in so many other intra-operative situations, permitting the
user to maintain a correct sense for the orientation and position
of the probe transducer.
[0009] Another issue faced by cardiothoracic surgeons is that of
finding coronary arteries in a difficult-to-assess patient.
Although in many patients the coronary arteries run close to or on
the surface of the heart, in perhaps 10% of patients one or more
coronary arteries are buried in cardiac tissue. This can create a
serious problem for a cardiothoracic surgeon attempting to perform
a bypass operation, in finding the correct artery. In a few
unfortunate cases, an artery has been misidentified, leading to
negative surgical results.
[0010] Moreover, the current configuration consisting of a
permanently attached probe connected to a cable presents sterility
issues. The cable typically could be autoclaved, but the sensor is
too delicate. The entire sensor and cable assembly, however, is
rather bulky for fitting into a bath of disinfecting liquid and the
connector is typically not designed to be immersed in disinfectant.
As a result, achieving satisfactory sterility of the probe and
cable assembly can present a challenge to hospital personnel.
[0011] Moreover, changing the command to the sensor head, for
example increasing or decreasing power, or changing the field of
view of the scan or the frequency transmitted for typical current
systems requires an adjustment at the imaging station, which is
awkward for a medical professional in the middle of a
procedure.
[0012] Although finger-mounted probes are currently known, they are
typically either bulky and inflexible or they do not form precise
imagery.
SUMMARY
[0013] The following embodiments and aspects thereof are described
and illustrated in conjunction with systems, tools and methods
which are meant to be exemplary and illustrative, not limiting in
scope. In various embodiments, one or more of the above-described
problems have been reduced or eliminated, while other embodiments
are directed to other improvements.
[0014] In a first separate aspect, the present invention may take
the form of an ultrasound finger probe assembly that has a
connector-half and a multi-conductor cable, electrically connected
to the connector-half. Also, a finger clip is adapted to be mounted
on a human finger and an ultrasound finger probe is supported by
the finger clip and includes elements adapted to provide
therapeutic ultrasound. The multi-conductor cable includes some
traces having a larger cross-section than others of the traces, the
larger cross section traces being adapted to provide electricity
for the therapeutic ultrasound elements.
[0015] In a second separate aspect, the present invention may take
the form an ultrasound finger probe having a finger clip that is
adapted to be mounted on a human finger and an ultrasound probe
that is supported by the finger clip. Also, control input elements
are mounted on the finger clip and are adapted to control the
operation of the ultrasound probe.
[0016] In a third separate aspect, the present invention may take
the form an ultrasound finger probe assembly that has a finger
clip, adapted to be mounted on a human finger and an ultrasound
probe, supported by the finger clip. Also, an optical viewing
device is physically associated to the ultrasound probe and a cable
is connected to the ultrasound probe and optical viewing device and
adapted to transmit data from the ultrasound probe and optical
viewing device to a further device.
[0017] In a fourth separate aspect, the present invention may take
the form an ultrasound probe assembly that has a finger-mounted
ultrasound imaging probe and a sensor that is physically associated
to the ultrasound imaging probe.
[0018] In addition to the exemplary aspects and embodiments
described above, further aspects and embodiments will become
apparent by reference to the drawings and by study of the following
detailed descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a perspective view of a probe assembly according
to the present invention, shown in its environment, attached to a
medical professional and ready for use.
[0020] FIG. 2 is a perspective view of the probe assembly of FIG.
1, in use on a patient.
[0021] FIG. 3 is a perspective view of an alternative embodiment of
the assembly of FIG. 1, having a wireless link to an imaging
station, in use on a patient.
[0022] FIG. 4 is a perspective view of the assembly of FIG. 1,
showing a probe retaining clasp, on the forearm unit, in use.
[0023] FIG. 5A is a perspective view of a work piece representing a
first step in a manufacturing process for the finger probe that is
part of the assembly of FIG. 1.
[0024] FIG. 5B is a perspective view of a work piece representing a
second step in a manufacturing process for the finger probe that is
part of the assembly of FIG. 1.
[0025] FIG. 5C is a perspective view of a work piece representing a
final step in a manufacturing process for the finger probe that is
part of the assembly of FIG. 1.
[0026] FIG. 6 is a side view of the finger probe of FIG. 1, showing
navigational elements.
[0027] FIG. 7 is a perspective view of an alternative embodiment of
the probe of FIG. 1, having a hypodermic needle attached.
[0028] FIG. 8 is a perspective view of an alternative embodiment of
the probe of FIG. 1, having an electric camera attached.
[0029] FIG. 9 is a perspective view of an alternative embodiment of
the probe of FIG. 1, having a set of sensors attached.
[0030] FIG. 10 is a perspective view of an alternative embodiment
of the probe of FIG. 1, having a set of controls attached.
[0031] FIG. 11 is a side view of a finger mounted probe, defining
an angle of interest.
[0032] FIG. 12 is a front view of the probe of FIG. 11, showing a
distance of interest.
DETAILED DISCUSSION OF THE PREFERRED EMBODIMENT
[0033] In a first preferred embodiment, the present invention takes
the form of an ultrasound imaging assembly 10. This assembly
includes an imaging station 12, which can include an auxiliary
display 13, for the user's convenience. Also, a first
multi-conductor electrical cable 14 is electrically attached to the
imaging station and terminates at a distal connector-half 16. A
second multi-conductor cable 18 extends from a shoulder mounted
connector half 20, which mates to the distal connector half 16 and
terminates at a wrist or forearm band 22 that supports a forearm
mounted connector-half 24. A finger probe sub-assembly 26 includes
a finger probe sub-assembly connector-half 28 that mates with the
forearm mounted connector-half 24. A cable in the form of a ribbon
29 extends from connector-half 28 to a finger-mounted probe 30.
[0034] In use, surgery may begin with the surgeon wearing the wrist
band 22, which retains connector-half 24 and cable assembly 18,
which includes shoulder mounted connector 20. At this stage it is
possible that no finger probe sub-assembly 26 would be attached to
cable 18 and that no station cable 14 would be connected to
assembly 18, so that the user would be free to move about freely.
This would also permit the surgeon full use of his hands while
making an initial incision and further initial surgical cutting.
When the area of interest in the patient's body has been accessed,
the surgeon can take a sub-assembly 26, that has been kept ready
for use, attach it to connector-half 24 and also have cable
assembly 18 connected to imaging station 12, by way of cable 14 and
connector-halves 16 and 20. This technique would destroy the
sterility of the performing person's hands, so it is advisable that
a person not otherwise participating in the surgery connect cable
18 to cable 14. Alternatively, a person having sterile hands could
briefly don sterile gloves to effect the connection and then doff
the gloves after finishing. In yet another possibility, the cable
14 is equipped with a sheath, which can be broken away and which is
sterile underneath.
[0035] The surgeon can then introduce his hand, with the probe 30
attached, into the patient in order to gather imagery, as shown in
FIG. 2. After the imagery is gathered, yielding an enhanced
knowledge of the problem being addressed, sub-assembly 26 can be
removed and detached from connector-half 24, to free the surgeon to
continue his procedure. Later on, when further imagery is required,
either the same sub-assembly 26 may be reattached or another
sub-assembly 26, maintained in sterility can be attached to perform
the further imaging. In a preferred embodiment, various probe
configurations are kept at the ready, to provide the surgeon with a
variety of image gathering options. This set of probes could vary
in transmit frequency also, so that a first probe permits detailed
imaging of fine structures, by using a relatively high frequency
(@10-20 MHz), and a second lower resolution probe permits imaging
of deeper structures using a lower ultrasound frequency (@2-10
MHz). Probes of various shapes and architectures are also made
available to permit varying field of views. For example a curved
linear array with relatively small radius of curvature permits
imaging in the near field of the probe over a wide field of view. A
phased array transducer permits imaging over a wide field of view
at some distance from the array, while allowing imaging through a
narrow access. A linear array permits imaging over a narrower field
of view but provides good imaging of structures near the surface of
the array. This is frequently the type of imagery that is highly
desirable in surgical situations.
[0036] The use of a linear array in a finger mounted probe can be
particularly advantageous. The probe can be configured so that the
linear array images a scan plane that is parallel to the length
dimension of the finger, or in another configuration, transverse to
the finger. For the parallel configuration a portion of the scan
looks forward from the finger, so that if the user directs his
finger to point at the body surface, the probe will image a scan
plane into the body. The user can then rotate the image plane by
twisting his wrist, something that is quite easy for most users to
do. In the case of a curved linear array, the curved surface
permits a user to rock the probe on the body or organ surface in
order to view tissue over a variety of contact angles. This is
particularly easy to do using a finger mounted probe, as the index
finger has a good freedom of movement in several axes. The
transverse mounted probe has the advantage that it permits a
physician to begin his examination with his hand transverse to the
length of the patient's torso, which is a more natural position
than parallel to the length of the patient's torso. A straight
linear array or a phased array, however, has the advantage that the
probe head profile can potentially be minimized, which is very
important in accessing body portions.
[0037] The probe assembly 10 is also very useful in non-surgical
procedures, for example, examination of a patient by imaging
through the body surface, at the same time the physician is
gathering tactile information. For example, the physician may wish
to examine a bump or discolored area on the patient's skin and
could by use of assembly 10 gather imagery at the same time he
touches the abnormal area to diagnose the nature of the problem.
Additionally, the user can make a fuller use of his muscle memory
and positional awareness to return the probe head to the same
location used in a recent probe use.
[0038] Probe assembly 10 is also used for exploration of body
cavities, such as the vagina, rectum or mouth. Again, the user
could both gain tactile information about an organ, such as the
prostate gland at the same time he is gaining image
information.
[0039] A physician may use assembly 10 to view difficult-to-access
areas within the body, during surgery. For example during open
heart surgery, the surgeon could move the probe 30 around to the
posterior of the heart to gain imagery of heart features, such as
valves that are difficult to otherwise image. This would be
extremely difficult with a rigid probe that is poorly shaped for
moving though tissue. A probe without advantageous physical
characteristics could easily damage a patient during this type of
use.
[0040] Referring to FIG. 2, in an additional example, assembly 10
can be used in an army field hospital to assist a surgeon in the
task of removing shrapnel from a wounded soldier. Although an
initial evaluation of the shrapnel locations could be made by an
assessment of the entry wounds and pre-surgical imaging, a great
deal might still not be known about the specific locations and
dimensions of the individual pieces of shrapnel. After making an
initial incision near an entry wound, the surgeon attaches a
sub-assembly 26 to connector-half 24 and introduces the finger
mounted probe 30 into the incision, to gain a further indication of
the shrapnel positions. After gaining this information, the surgeon
can quickly remove sub-assembly 26, so that he can have the full
use of both hands in the task of removing pieces of shrapnel
identified by the imaging. Later on during the same surgery, the
surgeon may wish to take further images and may reattach
sub-assembly 26, or some other sub-assembly 26, either for the sake
of sterility or for the sake of having different imaging
characteristics.
[0041] In another possible application, the low profile of probe 30
lends itself to imaging a premature infant in a neo-natal
incubator, by reaching through the small entry orifice of the
incubator. This action is difficult to do with currently available
ultrasound probes.
[0042] The system described above, having cables 14, 18 and probe
sub-assembly 26 has advantages both in providing a broad range of
connectivity and in easing the task of maintaining a sterile
operating theater. In a preferred embodiment, cable 18 may be
sterilized in an autoclave without being damaged. Cable 14 is
typically far enough removed from the sterile area so that it can
be wiped down with disinfectant between instances of use. Probe
sub-assembly 26 can be submerged in disinfectant fluid for
sterilization. In an alternative embodiment, cable 18 is protected
by a sterile sheath, which can be removed when a physician, who is
wearing cable 18, needs to move to a different imaging station 12
and use a different probe assembly 26. In another alternative,
probe assembly 26 is elongated, so that cable 18 does not have to
extend as far toward probe 30, thereby making it more likely for
cable 18 to avoid contamination from body fluids.
[0043] Also, cable 18 may be a universal unit, fitting to a broad
range of probe makes, by having a super-set of pins, not all of
which are used for any particular sub-assembly 26. An adapter is
provided that would be interposed between cable 18 and imaging
station 12, either where cable 18 connects to cable 14, where cable
14 connects to station 12, or as part of cable 14. A different
adapter is necessary for each make of imaging station 12. It should
be noted that this feature of system 10 can be used to increase the
usability for ultrasound probes that are not finger probes.
[0044] Referring to FIG. 3, in an alternative preferred embodiment
a wireless link is established between sub-assembly 26 and imaging
station 12. A data processing and transmission unit 32 receives the
signals from probe 30 and extracts the imagery, thereby greatly
reducing the volume of data to be transmitted. The imagery is
transmitted, typically by RF, to imaging station 12 and/or to
heads-up display goggles 34, which superimpose the imagery on the
user's field-of-view. In an alternative preferred embodiment unit
32 is located directly on the wrist band 22. Referring to FIG. 4,
in a preferred embodiment a catch 40 is provided on wrist band 22,
for the purpose of retaining probe 30, so that it can be folded
back, out of the way of the user's hand, when not in use. In an
alternative preferred embodiment, catch 40 is implemented by a
system of magnets, with mutually attractive magnets on wrist band
22 and probe 30. Probe sub-assembly 26 is made of light weight
materials and has a mass of less than 70 grams. The distal 3 cm of
probe 30, which includes the ultrasound transceiver, has a mass of
about 11 grams. This low mass is very important in enabling a user
to easily maneuver the probe 30.
[0045] Applicant notes, in connection with the immediately
following discussion, that flex-circuit is a term of art in the
electric device industry, referencing a connective element made of
a sheet of polymeric dielectric material having conductive traces
formed on it by photolithographic techniques. It may be sealed with
an additional sheet of polymeric material, so that the conductive
traces are interposed and sealed between the two sheets. Referring
to FIGS. 5A-5C, in one preferred embodiment construction of
sub-assembly 26 begins with the creation of a T-shaped piece of
flex circuit 40. In an alternative preferred embodiment, two
L-shaped pieces are placed side-to-side to form a T-shape. The
length 46 between a proximal end 42 and a distal end 43, of flex
circuit 40 is 25 cm. The length 48 of the T-shape top bar at distal
end 43 is 2.5 cm. The distal end T-shape top bar is made of a first
branch 44 and a second branch 45. Conductive traces 50, each turn
at the T-junction and extend almost the entire extent from proximal
end 42 to the end of either branch 44 or 45.
[0046] A set of bare trace ends 53 are formed at the free ends of
branches 44 and 45 by removing the end of the plastic of flex
circuit 40 from about traces 50, typically by laser ablation. An
ultrasound transceiver is formed by connecting the trace ends 53,
to a piece of piezoelectric material 56. After attachment, a high
performance acoustically absorptive backing material 54 is affixed
behind piezoelectric material 56, so that trace ends 53 are
encapsulated between backing material 54 and piezoelectric material
56. Backing material 54 may be as disclosed in U.S. Pat. No.
4,779,244, issued Oct. 18, 1988, which is incorporated by reference
as if fully set forth herein. In this patent a backing material
having an acoustic absorbance equal to or greater than 60 db/cm/MHz
is disclosed. Using such a material and given the need to attenuate
a typical 5 MHz ultrasound signal emitted from the back of the
array by approximately 150 dB through a two-way trip through the
material (so as not to interfere with the image), the array backing
would be approximately Xcm=150/(60 db/cm/Mhz*2*5 MHz)=2.5 mm, which
provides a very low profile for a transducer to fit on the
finger.
[0047] In instances where a high absorptive backing material is not
available, such as for a pre-existing probe retrofit, such a probe
could be modified by creating a toothed pattern, such as that found
on the sides of an anechoic chamber, in the surface of the backing
material that faces away from the ultrasound array. This causes the
sound waves reflecting off the rear of the ultrasound array stack
to scatter.
[0048] The piezoelectric material 56 is then patterned as shown,
with each resultant element created by this patterning being
connected to a unique trace 53. In a preferred embodiment, even
ultrasound elements are connected to branch 44, while the
interposed odd elements are connected to branch 45, or vice versa.
Skilled persons will appreciate that the alternative method of
construction noted above, in which two L-shaped pieces of flex
circuit are used, rather than a single T-shaped piece, permits the
step of connecting bare traces 53 to materials 54 and 56 to be
performed with the two L-shaped pieces of flex circuit laying flat,
thereby greatly easing this connective task. The two L-shaped
pieces may then be curled up and joined at the top, thereby forming
an annulus that fits about the finger.
[0049] Referring to FIG. 5C, the branches 44 and 45 are curved
downwardly to fit about a finger, so that ultrasound array 56 now
faces downwardly and is oriented to sweep from forward and backward
relative to the finger. A housing is added about the ring that is
formed by branches 44 and 45 and materials 54 and 56, to arrive at
a final probe 30, such as is shown in FIGS. 7-10. A protective
coating may be added to the medial portion of flex circuit 40.
Referring to FIGS. 11 and 12, a probe 30 constructed according to
the preferred methods described herein may have a distance 312 from
the interior surface 324 of the finger mount to the furthest
protrusion of the probe of about 1.2 cm, greatly facilitating a
user in passing the probe 310 through tight passages in the body.
In another embodiment distance 312 equals about 1.5 cm.
[0050] Moreover probe 30 is made in a preferred embodiment so that
the ultrasound transceiver protrudes gradually outwardly
(downwardly) from front to middle. Defining an angle 314, as the
angle between a probe surface that extends parallel to the user's
finger and the surface of the probe as it begins to protrude
outwardly, angle 314 is about 70.degree. at its maximum. In an
alternative preferred embodiment, angle 314 is about 60.degree. at
its maximum and in yet another preferred embodiment, this angle is
about 50.degree. at its maximum. In yet another preferred
embodiment, angle 314 is about 40.degree.. An additional angle 316
may be defined as the angle between a probe surface that extends
parallel to the user's finger and the surface of the probe as it
begins to extend outwardly, going from rear to front. It is also
desirable to minimize angle 316, so that as the probe is being
removed back though tissue, it disturbs the tissue as little as
possible. In a preferred embodiment this angle is about 40.degree..
In other preferred embodiments this angle ranges from 40.degree. to
70.degree..
[0051] A finger cot 320 is used to both isolate the front of the
finger from tissue, provide a rounded surface at the front of the
finger, which can be pushed through tissue with less chance of
causing damage, and making it possible for a probe unit 310 having
a fixed inner diameter 324 to accommodate a range of finger
thicknesses, by providing a range of cots having different
thicknesses. It is desirable to minimize the distance 318 between
finger cot 320 and probe surface 322. Although this distance is
shown as being on the order of 2 mm, in another preferred
embodiment distance 318 is zero, with the finger cot 320 being
flush with the probe surface.
[0052] This low profile and gradual protrusion greatly facilitates
a probe user in inserting the probe into small body cavities and
avoiding damage to delicate tissues. Along these lines it is
beneficial to have a "bullet shaped" probe that comes to a point
forward of the finger and smoothly expands to the area where the
transponder is located. This can be accomplished by equipping the
probe with a forward section that terminates distal to the finger
tip in a single point and expands transversely outwardly
approximately equally and smoothly in each direction, to yield the
bullet shape.
[0053] In one preferred embodiment a 128 element probe is
constructed and in an alternative preferred embodiment a 256
element probe is constructed. The probe head is completed by adding
a lens and housing. Skilled persons will recognize that although a
linear array is shown, a curved linear array could be constructed
just as easily, using the techniques shown, simply by curving the
piezoelectric material after it is diced. In an alternative
preferred method of construction, a separately formed ultrasound
transceiver is connected to flex circuit 40 by way of a flex
circuit connective tab.
[0054] The use of a high absorptive backing material 54,
incorporated into the array, as well as a method of construction
that obviates the need for connecting the flex circuit to a cable
in the probe head permits the formation of a lower profile probe
head. As noted elsewhere in this document, this low profile is
critical in permitting a user to locate the probe in tight spaces
internal to the human body without damaging body tissue. The
benefit of this innovation may be utilized in probes that do not
otherwise fit the disclosure of this application. For example, flex
circuit 40, rather than terminating in connector-half 24, can be
terminated at a multi-conductor coaxial cable, of the type that is
currently standard in the ultrasound imaging industry, 5 cm or more
away from the probe with or without a connector. In the typical
current probe design, the multi-conductor coaxial cable terminates
quite close to the probe head or in the probe head, causing the
finger-mounted portion to be bulky and heavy. By extending the flex
circuit portion more than 5 cm from the probe itself, and
preferably more than 10 cm or even 20 cm, the finger-mounted
portion is kept light and given a low profile. Accordingly, the
present invention is not limited to the system connectors that
although advantageous do not by themselves yield the low profile of
the probe.
[0055] In an alternative preferred embodiment a capacitive
micro-machined ultrasound transceiver (CMUT) is connected to traces
50, using the same techniques as used for connecting piezoelectric
material 56. A CMUT transceiver tends to be thermally robust,
thereby lending itself to use in a probe that may be exposed to the
heat and pressure of an autoclave sterilization cycle, without
being damaged.
[0056] Referring to FIGS. 5A-5C, at the proximal end 42 of work
piece 40, a set of electrical contact points 52 are formed by
removing the flex circuit plastic down to each trace 50, in a
particular spot. Conductive material is deposited onto contacts 52,
so that they are not recessed. Alternatively, a surface coating
material covers flex traces so that only connector contacts 52 are
left exposed on the surface of flex forming contacts 52. Rigid
backing material 58 is adhered underneath the flex circuit and a
metal housing (not shown) is provided to finished connector-half
22. Alternatively, the proximal end of the flex circuit can be
selectively rigidized by laminating a rigid, circuit board material
layer onto the flexible portion, and forming connections to the
flex traces by laser or mechanical drilling and subsequent plating,
to form a monolithic integrated connector assembly.
[0057] Referring to FIG. 6, in a preferred embodiment a finger
probe 70 includes a set of accelerometers (not shown) and/or
inductors 72 that are mounted in a mutually orthogonal pattern are
provided as part of finger probe 30 to permit location
determination while finger probe 30 is within the body and not
directly observable.
[0058] Referring to FIG. 7 in an additional preferred embodiment, a
hypodermic needle 200 and an attached syringe 210 are releasably
mounted adjacent finger probe 30. This permits imagery gathered by
finger probe 30 to assist a health care professional in finding a
blood vessel of interest. Health care professionals sometime need
to find a particular blood vessel, such as the jugular vein, in
order to inject fluid or drugs as soon as possible so that the
substance being injected will reach a target organ as quickly as
possible. In such application, known as central-line-placement,
color flow ultrasound imagery, in which Doppler flow information
drives the display of the blood vessels and non-Doppler information
drives the display for the surrounding tissue, is particularly
useful in this endeavor. In an alternative preferred embodiment,
another sort of skin broaching device, such as a canula (not shown)
or a hypodermic needle connected to an intravenous drip bag is
associated to the ultrasound probe. Guidance of the hypodermic
needle associated with the finger probe may also be assisted by use
of commercially available guidance devices, such as a pressure
sensor associated with the needle, including that available from
Vascular Technologies, Ness-Ziona, Israel, which provide an
additional positive indication when the needle enters a vein,
through sensing a pressure change.
[0059] An additional preferred embodiment is the same as described
above except for that an optical link 260 and light source 262 is
provided to permit optical viewing of body tissue. In one preferred
embodiment the optical link 60 is in the form of a lens coupled to
a fiber optic link on probe 30 that may terminate in a video
camera. Alternatively optic link 260 is in the form of a video
camera (as shown) attached to the finger probe 30 and adapted to
communicate electrically with the imaging station 12, or heads up
display 34. In either situation it is necessary to provide light
for the optical link 260. This is accomplished either by an
electrically powered light source, such as a light emitting diode
262, or a chemically powered light source (not shown), such as
those available under the trade name "pin lights," from Embo-Optics
of Beverly, Mass.
[0060] Referring to FIG. 9, in another preferred embodiment a
finger probe, such as 30, is equipped with a sensor suite that
includes a thermometer 280, an oximeter 282, a pressure sensor 284
and a glucometer 286. In an alternative embodiment element 286 is
an agent administration patch 286 that is electrically activated by
a trace 50 to express the agent, thereby administering the agent to
a precise location. In an alternative preferred embodiment, a
smaller set of sensors is provided, or even a single sensor
only.
[0061] In another preferred embodiment, a finger assembly 130 is
provided that can both image tissue, using ultrasound, and that can
also provide therapy, typically by cauterizing tissue, also using
ultrasound. First there is an assembly 288 that includes both an
imaging array 292 and a treatment array 294. The treatment array
uses up to 100 watts of power and is powered by traces that are
larger in cross-sectional dimension and are therefore capable of
conducting more current in order to meet the greater power demands
of treatment array 294. In an alternative embodiment a smaller
number of sensors, or just one sensor, are available.
[0062] In another preferred embodiment of an ultrasound assembly
(not shown), a single array is used for both imaging and treatment.
In one variant if this embodiment, some piezoelectric elements are
used for both imaging and treatment and others are used solely for
imaging. Again, the array must be powered by a larger input of
current and to accommodate this need, larger cross-section traces
40 (FIG. 5A) are provided for the treatment ultrasound
elements.
[0063] A set of thumb controls 290 are provided for probe 288, so
that the user may switch between imaging and treatment. These
controls are typically in the form of a small push button that must
be pressed in a specific pattern, for example two rapid presses
followed by continuous pressure during the period of time treatment
is desired, in order to activate treatment mode, as any inadvertent
activation could greatly harm a patient. In one preferred
embodiment a warning signal is given when two rapid presses have
placed the treatment probe in a "ready" state, in case some passage
through tissue ever causes two rapid presses to occur. In an
alternative preferred embodiment controls are placed on the wrist
or forearm band 22, thereby providing easy access for a probe
user.
[0064] In another preferred embodiment, buttons 290 are provided
for a probe, such as probe 30, in which therapeutic ultrasound is
not available. The buttons are instrumented to change the scan
width and orientation; the transmit power and frequency; and
imaging mode among other quantities. The buttons 290 communicate
with imaging station 12 by way of traces 50 and cables 18 and 14 or
by RF transmission in the embodiment of FIG. 3. The buttons 290 may
also communicate or be mechanically associated with the array
within the finger probe to allow a change in orientation of the
array elements to effect the orientation of the scan plane.
[0065] One use of probe 30 is for the intra-operative evaluation of
plaque deposits in the aortal arch and ascending aorta, prior to
accessing the aorta. To perform this function a Doppler probe may
be used and a measurement of the speed of the blood in the aorta
formed. In the case where the aorta has been narrowed due to plaque
deposits, the blood flows more rapidly. The accessing of the tissue
of the aorta is greatly eased by use of a finger mounted probe, as
opposed to the long, stiff intra-operative probes currently
available.
[0066] While a number of exemplary aspects and embodiments have
been discussed above, those of skill in the art will recognize
certain modifications, permutations, additions and sub-combinations
thereof. It is therefore intended that the following appended
claims and claims hereafter introduced are interpreted to include
all such modifications, permutations, additions and
sub-combinations as are within their true spirit and scope.
* * * * *