U.S. patent application number 11/544261 was filed with the patent office on 2007-07-05 for cervimetry control apparatus.
This patent application is currently assigned to Intrapartum Ventures, LLC. Invention is credited to Tim Baird, Dharmesh Dubey.
Application Number | 20070156068 11/544261 |
Document ID | / |
Family ID | 37966478 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070156068 |
Kind Code |
A1 |
Dubey; Dharmesh ; et
al. |
July 5, 2007 |
Cervimetry control apparatus
Abstract
The present invention provides a medical device for measuring
cervical dilation including an elongate body defining a proximal
end and a distal end, as well as an expandable element coupled to
the distal end of the elongate body. An array of movable elements
may be disposed circumferentially about the elongate body, where
the array of movable elements is movably coupled to the distal end
of the elongate body by a plurality of wires. The medical device
may further include a measurement mechanism able to determine a
radial spacing of the array of movable elements, as well as a
dilation indicator in communication with the measurement mechanism.
One or more pressure sensors may be coupled to the array of movable
elements, whereby a control element is in communication with the
pressure sensors. In addition, an inflation source may be included
in fluid communication with the expandable element.
Inventors: |
Dubey; Dharmesh;
(Jacksonville, FL) ; Baird; Tim; (Ponte Verda
Beach, FL) |
Correspondence
Address: |
Christopher & Weisberg, P.A.
Suite 2040, 200 East Las Olas Boulevard
Ft. Lauderdale
FL
33301
US
|
Assignee: |
Intrapartum Ventures, LLC;
|
Family ID: |
37966478 |
Appl. No.: |
11/544261 |
Filed: |
October 6, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11401623 |
Apr 10, 2006 |
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11544261 |
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11401749 |
Apr 11, 2006 |
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11401623 |
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11321061 |
Dec 29, 2005 |
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11401749 |
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Current U.S.
Class: |
600/588 ;
600/591 |
Current CPC
Class: |
A61B 5/1076 20130101;
A61B 5/6885 20130101; A61B 2562/043 20130101; A61B 2562/247
20130101; A61B 2562/0247 20130101; A61B 5/435 20130101 |
Class at
Publication: |
600/588 ;
600/591 |
International
Class: |
A61B 5/103 20060101
A61B005/103; A61B 5/117 20060101 A61B005/117 |
Claims
1. A cervimetry device for measuring cervical dilation, comprising:
an expandable element; an inflation source in communication with
the expandable element; and a control element for controlling the
inflation source and indicating a cervical dilation
measurement.
2. The cervimetry device according to claim 1, further comprising
an array of movable elements disposed circumferentially about the
expandable element.
3. The cervimetry device according to claim 2, further comprising
at least one pressure sensor coupled to at least one of the movable
elements, the pressure sensor being in communication with the
control element.
4. The cervimetry device according to claim 1, further comprising
an exhaust valve in fluid communication with the expandable
element, wherein the exhaust valve is also in communication with
the control element.
5. The cervimetry device according to claim 1, wherein the control
element includes a display.
6. The cervimetry device according to claim 1, wherein the control
element includes a control actuator for receiving input from a
user.
7. The cervimetry device according to claim 1, wherein the control
element includes an electronic storage medium.
8. The cervimetry device according to claim 1, further comprising
an elongate body defining a proximal end and a distal end, wherein
the expandable element is movably coupled to the distal end of the
elongate body, and the control element is coupled to the proximal
end of the elongate body.
9. The cervimetry device according to claim 8, further comprising a
distal pad coupled to the distal end of the elongate body.
10. The cervimetry device according to claim 9, further comprising
a distal pressure sensor coupled to the distal pad, wherein the
distal pressure sensor is in communication with the control
element.
11. The cervimetry device according to claim 8, further comprising
a camera coupled to the distal end of the elongate body, wherein
the camera is in communication with the control element.
12. The cervimetry device according to claim 8, further comprising
a lighting element coupled to the distal end of the elongate body,
wherein the lighting element is in communication with the control
element.
13. A cervimetry device for measuring cervical dilation,
comprising: an expandable element; an array of movable elements
disposed about the expandable element; an inflation source in
communication with the expandable element; at least one pressure
sensor coupled to at least one of the array of movable elements;
and a control element for controlling the inflation source and
indicating a cervical dilation measurement, wherein the control
element is in communication with the at least one pressure
sensor.
14. A method for performing a cervical procedure, comprising the
steps of: providing a cervimetry device including an expandable
element, an inflation source in communication with the expandable
element, and a control element for controlling the inflation source
and indicating a cervical dilation measurement; positioning the
cervimetry device proximate to a cervical tissue region; operating
the inflation source to expand the expandable element and contact
the cervical tissue region; measuring a contact pressure between at
least a portion of the cervimetry device and the cervical tissue
region; and terminating operation of the inflation source in
response to the measured pressure level.
15. The method according to claim 14, wherein the cervimetry device
further includes an exhaust vale in fluid communication with the
expandable element, and further comprising the step of actuating
the exhaust valve in response to the measured pressure level.
16. The method according to claim 14, wherein the cervimetry device
further includes an array of movable elements disposed about the
expandable element.
17. A method for performing a cervical procedure, comprising the
steps of: providing a cervimetry device including an expandable
element, an inflation source in communication with the expandable
element, and a control element for controlling the inflation source
and indicating a cervical dilation measurement; positioning the
cervimetry device proximate to a cervical tissue region; operating
the inflation source to expand the expandable element; measuring a
dimension of the expandable element; and terminating operation of
the inflation source in response to the measured dimension.
18. The method according to claim 17, wherein the cervimetry device
further includes an exhaust vale in fluid communication with the
expandable element, and further comprising the step of actuating
the exhaust valve in response to the measured pressure level.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of and claims
priority to both pending Utility patent application Ser. No.
11/401,623, filed Apr. 10, 2006, entitled METHOD FOR CERVICAL
DILATION AND/OR MEASUREMENT, and pending Utility patent application
Ser. No. 11/401,749, filed Apr. 11, 2006, entitled CERVICAL
DILATION MEASUREMENT APPARATUS, each of which is a
continuation-in-part of and claims priority to pending Utility
patent application Ser. No. 11/321,061, filed Dec. 29, 2005,
entitled CERVIMETER, the entirety of each of which is incorporated
herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] n/a
FIELD OF THE INVENTION
[0003] The present invention relates to obstetric devices and more
particularly, to a method and apparatus for monitoring and
controlling cervical dilation.
BACKGROUND OF THE INVENTION
[0004] During the later stages of pregnancy, the cervix typically
undergoes numerous physical changes which provide increased safety
and ease with which the fetus can be delivered. Particularly, the
cervical canal tissue softens and increases in pliability, and
subsequently, the diameter of the cervical canal begins to
increase. Eventually, the dilation of the cervix is completed,
allowing for the unobstructed passage of the fetus.
[0005] Cervical diameter is monitored throughout labor and is
instrumental in diagnosing such conditions as dysfunctional or
arrested labor, to determine whether labor augmentation or a
cesarean section should be performed, as well as to establish
whether or when various pharmaceutical agents should be
administered. Physical examination of the cervical diameter is
generally performed by inserting two fingers into the vagina and up
to the cervix. Upon reaching the cervix, the fingers are spread
apart to determine the approximate dilated diameter. While an
obstetrician may be fairly experienced in performing a manual
cervical diameter measurement, the accuracy of such a measurement
can be highly subjective and can further vary depending on the
particular experience, judgment, and even finger size of the
attending physician. Considering the importance of the cervical
dilation measurement in assessing labor progression, it is crucial
to provide dilation information that is precise as well as
reproducible among different healthcare providers or
physicians.
[0006] Given the subjectivity and probability of inaccurate or
imprecise dilation measurements, it would be desirable to provide
for the precise and accurate attainment of cervical dilation
measurements on a repeat basis during the course of labor. In
addition, it would be desirable to provide for ease of monitoring
and control of cervical dilation to assist a physician throughout
labor management.
SUMMARY OF THE INVENTION
[0007] The present invention advantageously provides a method and
system for the accurate and precise measuring of cervical dilation
during labor, as well as a method and system for performing
cervical dilation. The medical device of the present invention may
include an elongate body defining a proximal end and a distal end,
with the elongate body further including an inflation lumen. An
expandable element may be coupled to the elongate body in fluid
communication with the inflation lumen, and an array of movable
elements may be circumferentially disposed about the elongate body,
with the array of movable elements being movably coupled to the
elongate body by a plurality of wires. The medical device may also
include a measurement mechanism able to determine a radial spacing
of the array of movable elements, where the measurement mechanism
can include a tension ring coupled to the plurality of wires. In
addition, a dilation indicator can be provided in communication
with the measurement mechanism, while at least one pressure sensor
may be coupled to at least one of the array of movable elements.
Moreover, a distal pressure sensor can be coupled to the distal end
of the elongate body, with the medical device also providing a
control element in communication with the at least one pressure
sensor and the distal pressure sensor. The medical device can also
include an inflation source in fluid communication with the
expandable element, as well as an exhaust valve in fluid
communication with the expandable element. Furthermore, the medical
device may include a camera as well as a lighting element coupled
to the distal end of the elongate body, thereby providing visual
feedback to aid in the positioning of the device.
[0008] The control element of the present invention may further
provide for monitoring and controlling the operation of the medical
device. The control element may be in communication with the one or
more sensors disposed on the medical device, as well as being in
communication for control and/or monitoring of the additional
components of the medical device, such the camera, lighting source,
inflation source, or the like. The control element may provide a
display or other indication elements for conveying information,
such as pressure, size, etc. to a physician during a particular
procedure. Moreover, the control element may provide for additional
patient safety by having an automatic alarm and/or shut down
process in response to measurements and/or conditions that differ
from a pre-determined set of parameters.
[0009] In an alternative embodiment, the present invention also
provides a cervical dilation sensor to aid in the manual,
two-finger approach commonly employed. The cervical dilation sensor
may include a first rod, a second rod, and a sensor housing. The
first and second rods may be rotatably and pivotably coupled to the
sensor housing, as to freely move about the housing in at least two
planes of motion. The sensor housing may include one or more
sensors coupled to the first and second rods as to measure the
relative movement of the two rods, while the cervical dilation
sensor may also include a control monitor in communication with the
one or more sensors in the sensor housing for displaying and
monitoring information provided by the sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A more complete understanding of the present invention, and
the attendant advantages and features thereof, will be more readily
understood by reference to the following detailed description when
considered in conjunction with the accompanying drawings
wherein:
[0011] FIG. 1 is an illustration of an embodiment of a medical
device in accordance with the present invention;
[0012] FIG. 2 is a side view of a distal end of the medical device
of FIG. 1;
[0013] FIG. 3 is a cross-sectional view of a distal end of the
medical device of FIG. 1;
[0014] FIG. 4 is an additional cross-sectional view of the medical
device of FIG. 1;
[0015] FIG. 5 is a cross-sectional view of an embodiment of a
dilation indicator in accordance with the present invention;
[0016] FIG. 6 is an illustration of an embodiment of a control
element in accordance with the present invention;
[0017] FIG. 7 is an illustration of a distal end of a medical
device in a deflated state in accordance with the present
invention;
[0018] FIG. 8 is an illustration of a distal end of a medical
device in an inflated state in accordance with the present
invention;
[0019] FIG. 9 is a flow chart of an embodiment of a method of use
of a medical device of the present invention;
[0020] FIG. 10 is a perspective illustration of an embodiment of a
cervical dilation sensor in accordance with the present
invention;
[0021] FIG. 11 is a side view of the cervical dilation sensor of
FIG. 10;
[0022] FIG. 12 is an additional illustration of the cervical
dilation sensor of FIG. 10;
[0023] FIG. 13 is yet another depiction of the cervical dilation
sensor of FIG. 10.
[0024] FIG. 14 shows an embodiment of a cervical dilation sensor
coupled to a hand;
[0025] FIG. 15 depicts an embodiment of a cervical dilation sensor
within a glove;
[0026] FIG. 16 illustrates an additional embodiment of a cervical
dilation sensor coupled to a hand;
[0027] FIG. 17 shows an embodiment of a calibration element for use
with a cervical dilation sensor in accordance with the present
invention; and
[0028] FIG. 18 is a flow chart of an embodiment of a method of use
of a cervical dilation sensor in accordance with the present
invention;
DETAILED DESCRIPTION OF THE INVENTION
[0029] As shown in FIG. 1, the present invention provides a medical
device 10 for measuring and performing cervical dilation. The
medical device 10 includes an elongate body 12 defining a proximal
end 14 and a distal end 16. The medical device 10 may further
include a dilation indicator 18 coupled to the proximal end 14 of
the elongate body 12 that is capable of providing a visual
indicator of the dilation measurement made by the medical device
10, as well as a control element 20 and an inflation source 22,
which will be discussed in more detail below.
[0030] Now referring to FIG. 2, the medical device 10 may further
include an array of movable elements 24 disposed circumferentially
about an axis of the elongate body 12, where the array of movable
elements 24 is located in proximity to the distal end 16 of the
elongate body 12. The array of movable elements 24 are movable in a
radial direction as to expand and contact with the tissue of the
cervix when positioned for measurement of cervical dilation.
Moreover, the array of movable elements 24 may be retracted upon
completion of the desired measurement to ease the withdrawal of the
medical device 10 from the patient. Each movable element may define
an upper portion 26 and a lower portion 28. In addition, each
movable element may define a channel 30 such that one or more
pressure sensors 32 may be mounted or otherwise positionable within
the channel 30 of the movable element. Moreover, an outer cushion
34 may be coupled to an outer surface of each movable element,
where the outer cushion 34 may be constructed from a gel-like
material or other suitable padding. The array of movable elements
24 may further be movably coupled to the elongate body 12 of the
medical device 10 by a plurality of wires 36 coupled to the upper
and lower portions of the movable elements 24, where the plurality
of wires 36 further extend through a length of the elongate body
12.
[0031] While the array of movable elements 24 may be extended and
retracted by manipulating the plurality of wires 36, an actuating
mechanism may be provided to facilitate movement of the array of
movable elements 24 from a retracted position to an extended
position, and vice versa. The actuating mechanism may include a
spring mechanism, a telescoping element, or, alternatively, the
medical device 10 may include an expandable element 38, such as a
balloon. Now referring to FIG. 3, the medical device 10 of the
present invention may further include the expandable element 38
coupled to or otherwise disposed on the elongate body 12 at or near
the distal end 16 of the elongate body 12. The expandable element
38 may be configured in a myriad of shapes, including a toroidal
configuration in which the expandable element 38 defines a
ring-like, "O" shape. Moreover, an inflation lumen 40 can be
included in fluid communication with the expandable element 38,
where the inflation lumen 40 is disposed within and traverses a
substantial length of the elongate body 12.
[0032] The medical device 10 of the present invention may include
additional features providing safety, ease of use, and the like.
For example, the medical device 10 may include a protective sheath
42 encasing at least a portion of the distal end 16 of the elongate
body 12. The sheath 42 may include one or more layers of various
materials to provide a water-tight seal around the medical device,
as well as adding to patient comfort by having additional padding
and/or a lubricious coating to ease positioning of the device. For
example, a first layer may completely enclose the medical device to
ensure the device is not exposed to external fluids or objects. A
second layer may be placed over the first layer as a protective
layer which is removable by a physician or operator after each use,
thereby providing a sterile layer and the possibility for re-use of
the medical device. A third layer may be provided over the second
layer and include a lubricious property allowing for smooth
insertion, operation, and removal of the device.
[0033] Furthermore, a distal pad 44 may be coupled to the elongate
body 12 at or near the distal end 16, where the distal pad 44 may
be contoured or shaped to conform to the curvature of the head of a
baby. In addition, a distal pressure sensor 46 may be coupled to
the distal pad 44 to aid in monitoring the positioning of the
medical device 10 and for determining contact with the cervix or
with the baby. The distal pad 44 and distal pressure sensor 46 may
provide feedback to a physician and aid in the axial positioning of
the medical device 10 upon insertion into a patient. Furthermore, a
camera 45 and a lighting element 47 may also be coupled to the
distal portion of the medical device. The camera 45 may be a
miniaturized instrument or pin-hole camera as commonly employed in
endoscopic surgical procedures, while the lighting element 47 may
include a diode, fiber optic, or other illumination mechanism as is
known in the art. The camera 45 and lighting element 47 may provide
visual feedback to a physician to further aid in maneuvering and
positioning the medical device when in use.
[0034] As shown in FIG. 4, the elongate body 12 may define a
plurality of wire lumens 48 for slidably receiving a portion of
each of the plurality of wires 36 coupled to the array of movable
elements 24. Each wire of the plurality of wires 36 may be slidably
positioned within each of the plurality of wire lumens 48 as to
slide freely with little friction, thereby facilitating the
movement of the array of movable elements 24 when the medical
device 10 is in use. The wires 36 may have sufficient length as to
extend through the entire length of the respective wire lumens 48,
and may further extend out of the proximal end 14 of the elongate
body 12.
[0035] The medical device 10 of the present invention may further
include a measurement mechanism for monitoring and/or quantifying
the movement of the array of movable elements 24 when the medical
device 10 is in use. For example, as shown in the FIG. 5
illustration of a cross-section of the dilation indicator 18, the
medical device 10 may include a tension ring 50 coupled to the
plurality of wires 36 such that the tension ring 50 moves as the
wires 36 extend and retract in response to the movement of the
array of movable elements 24. The tension ring 50 may further be
slidably coupled to the dilation indicator 18, where the dilation
indicator 18 conveys a dilation measurement in response to the
relative motion of the tension ring 50, the plurality of wires 36,
and thus, the array of movable elements 24. The dilation indicator
18 may include predetermined values calculated from the movement of
the tension ring 50 as to eliminate the need for a physician to do
any calculating to determine the dilation measurement.
[0036] Again referring to FIG. 1, in an exemplary system, the
proximal end 14 of the medical device 10 of the present invention
is coupled to the control element 20, through which a physician may
monitor and/or control the various components of the medical device
10. The control element 20 may be in communication with any of the
numerous sensors provided on the medical device 10, and may further
be in communication with additional components of the medical
device 10, such as the inflation source 22, the camera 45, and/or
the lighting element 47. In an exemplary embodiment, the control
element 20 may include a console that may be wrist-mounted to ease
the overall use of the medical device 10.
[0037] The control element 20 may include a display, such as an LCD
screen or the like, as well as other visual, audio, or tactile
indicators to convey information regarding the various operating
characteristics and conditions of the medical device 10 to an
operator or physician, including dilation measurements, dilation
pressure exerted by the medical device, inflation pressure, etc.
The control element 20 may further include one or more control
actuators, such as push-buttons, switches, a touch-screen, or the
like, to enable a physician to provide input to the control element
in order to manipulate and/or control a particular component or
function of the medical device 10.
[0038] In addition, the control element 20 may include a processor
component and an electronic storage medium (not shown) for storing
patient information, measurements and/or procedural information
obtained during use of the medical device. The control element 20
may provide calculations and graphical illustrations including, but
not limited to, a display of air pressure versus time, air pressure
versus diameter, upper and lower limits of expansion pressure, etc.
The control element 20 may further contain date/time information
for measurements, the physician or nurse performing the procedure,
and the like. Moreover, the control element 20 may be able to
communicate such recorded information to other devices and/or
systems in the hospital environment through the use of portable
media and/or wireless technologies as is known in the art.
[0039] In an exemplary embodiment, as shown in FIG. 6, the control
element may include a housing including an visual display 52, a
plurality of LEDs 54, and a plurality of control actuators 56
(shown as push buttons) which may be in communication with the
camera 45, light 47, and/or the inflation source 22, as previously
described. In addition, the housing of the control element 20 may
be mounted on the wrist of a physician through one or more coupling
elements 58. Moreover, to further ease use, the visual display 52
may be movably coupled to the housing so that a physician may
change the viewing angle or orientation of the screen during use of
the medical device. A particular use of the control element 20
during a cervical procedure with the medical device is described
further below.
[0040] The inflation source 22 of the medical device may be coupled
to the inflation lumen 40 at the proximal end 14 of the elongate
body 12, where the inflation source 22 is able to provide a fluid
or gas into the inflation lumen 40 for subsequent delivery to the
expandable element 38. Examples of a suitable inflation source 22
may include manual pumps, powered pumps, or the like. The inflation
source may be either separate from the control element, as shown in
FIG. 1, or integral with the control element 20 as shown in FIG. 6.
Moreover, an exhaust valve 60 may be in fluid communication with
both the inflation source 22 as well as the inflation lumen 40 for
subsequent control of the release of fluid from the medical device
10, and may further be in communication with and/or controlled by
the control element 20.
[0041] Referring now to FIGS. 7 and 8, in an exemplary use of the
medical device 10 of the present invention, a precise dilation
measurement may be performed during the various stages of labor.
The medical device 10, in a deflated state, may be positioned such
that the distal end 16 of the elongate body 12 is in proximity to
the dilated region of the cervix 54. Proper positioning can be
aided by feedback provided by the distal pressure sensor 46 when
contacting the cervix or the head 56 of the baby, as well as
monitoring the visual feedback from the camera 45. The sensor
feedback as well as images obtained by the camera 45 may be
displayed on the LCD screen of the control element. Upon proper
positioning, the array of movable elements 24 may be extended to
contact the tissue of the cervix 54, for example, by actuating the
inflation source 22 to inflate the expandable element 38. As the
expandable element 38 is inflated and subsequently expands, the
array of movable elements 24 located around the periphery of the
expandable element 38 will move outward in a radial direction,
while lengths of the plurality of wires 36 will be drawn further
into the respective plurality of wire lumens 48. As the array of
movable elements 24 is coupled to the plurality of wires 36, which
are further coupled to the tension ring 50, the expandable element
38 will expand outward uniformly from the elongate body 12.
[0042] The inflation source 22 may continue to inflate the
expandable element 38 until the movable elements 24 of the medical
device 10 come into contact with the dilated or undilated cervix
54. Such contact can be indicated and monitored through information
provided by the pressure sensors 32 coupled to the movable elements
24, which, again, may be relayed to a physician or operator through
the control element. In particular, the control element may provide
a visual indicator of the pressure being exerted on the cervical
tissue by the expansion of the medical device as well as the
overall dilation measurements of the cervix. Furthermore, the
control element 20 may include an algorithm or computational
ability to determine if the pressure sensor feedback indicates a
substantially uniform circular state. That is to say, that the
pressure measurements from each of the pressure sensors 32 disposed
about the movable elements 24 are approximately the same. When the
desired inflation level or diameter has been attained as indicated
by pressure sensor measurements or from the dilation indicator, the
inflation source 22 may be deactivated, or, alternatively, the
exhaust valve 60 may be triggered to prevent additional fluid from
entering the expandable element 38. Each of these events may be
triggered and/or controlled by actuator elements included on the
housing of the control element.
[0043] Once appropriately inflated, the measuring mechanism and the
dilation indicator 18 can provide the dilation measurement as
indicated by the distance the plurality of wires 36, and thus the
tension ring 50, traveled in reaching the expanded state. As
previously stated, the dilation indicator 18 can directly correlate
the distance traveled by the wires 36, and thus, the measured
expansion of the movable elements 24, to an accurate and precise
dilation measurement.
[0044] Upon completion of the desired measurement, the movable
elements 24 are retracted towards the elongate body 12, i.e., by
deflating the expandable element 38 by opening the exhaust valve
60, upon which the movable elements 24 will retract to a closed
position for the removal of the medical device 10 from the patient.
Both the tension ring 50 and the plurality of wires 36 may be
biased towards a closed, retracted position, such that when the
expandable element 38 is not under positive inflation pressure, the
medical device 10 retains a closed, retracted state. Furthermore,
as described above, the medical device 10 may include an outer
sheath 42 which, if used, may be removed and replaced for
subsequent uses of the medical device 10, thereby providing a
re-usable device while maintaining the sterility of the medical
environment.
[0045] Referring to FIG. 8, in an alternative use of the medical
device 10 of the present invention, the distal portion of the
medical device 10 may be employed to produce a safe and uniform
cervical dilation where a desired dilated condition has not yet
occurred or otherwise been achieved. The medical device 10 may be
positioned proximate to a region of an undilated cervix and the
array of movable elements 24 of the medical device 10 may be
expanded to contact the cervical tissue 54. Similar to obtaining a
dilation measurement as described above, the distal pad, pressure
sensors or camera may provide feedback to a physician or operator
to aid in the axial positioning of the device. Through monitoring
information from any of the aforementioned components, through the
control element for instance, the medical device may traverse the
length of the cervix while reducing the likelihood of accidentally
perforating the uterus, which may occur with the use of
conventional devices.
[0046] Upon initiating the desired contact, the array of movable
elements 24 may then be extended further, for example, through a
controlled inflation of the expandable element 38, in order to
provide a desired rate of expansion, and thus, dilation.
Alternatively, the array of movable elements may be actuated to
extend outward through pressure or force applied through the
plurality of wires 36, or by other actuating mechanisms as known in
the art. At any point during the dilation procedure, information
may be provided regarding the amount of force being applied to the
cervical tissue via the one or more pressure sensors 32 coupled to
the array of movable elements 24, as well as the radial spacing of
the array of movable elements. As such, through the monitoring of
sensor feedback information, the dilating force applied to the
array of movable elements either through the plurality of wires 36
or by the expandable element 38 may be appropriately adjusted in
order to achieve the desired dilation without unnecessarily
damaging the cervical tissue. Additionally, the spacing of the
array may be monitored to achieve a desired dilated state. Through
the monitoring and manipulation of the operating characteristics of
the medical device, including the rate of extension of the array,
the pressure between the medical device and the tissue, and/or the
distance traveled and thus the radial spacing of the array, a
precise and accurate dilation may be induced.
[0047] The above-described dilation may be performed for
obstetrical uses, for example, in cervical "ripening" to assist in
the induction of labor in cases of poorly dilated or effaced
cervices. In addition, pre-operative dilation may be performed
using the medical device of the present invention in cases of
uterine curettage for failed pregnancy, miscarriage, or retained
products of conception. Moreover, the medical device may be used
for gynecological purposes of cervical dilation in cases of
curettage of the endocervix or endometrium, elective termination of
pregnancy, diagnostic and operative hysteroscopy, thermal
endometrial ablation techniques, as well as treatment of cervical
stenosis.
[0048] While it has been discussed that the control element may
provide a variety of information from the numerous sensors and
other components to a physician or operator during the
above-mentioned procedures, the control element may further provide
for enhanced safety during use by including pre-determined
circumstances and/or threshold values for safe operation,
irrespective of whether the aim is to take measurements or to cause
dilation. Now referring to FIG. 9, for example, the medical device
may be positioned initially in the cervix, while values obtained
from the distal pressure sensor are monitored. Should a particular
pressure be experienced that exceeds a pre-determined safe
operating pressure that could damage the baby or surrounding
tissue, the control element 20 may provide an audio, visual, or
tactile alarm to the operator to withdraw the device. Upon proper
positioning, the inflation source 22 may be actuated. Should a
pressure in the inflation lumen, RPM, or other indicator of the
operation of the inflation source 22 differ from expected values,
the control element 20 may again cause an alarm and/or
automatically terminate operation of the inflation source 22.
Similarly, during use of the medical device 10, if the pressure
being exerted on the cervical tissue during expansion is greater
than desired, or should the diameter of the expanded portion of the
medical device appear out of the desired range, the control element
20 may convey these circumstances through visual, audio or tactile
indicators and/or initiate a shut-down sequence of events, which
may include deflation, retracting the array or movable elements,
etc.
[0049] Now referring to FIGS. 10-13, in an alternative embodiment
of the present invention, a cervical dilation measurement device
100 is provided to aid in the manual, two-finger approach of
measuring cervical dilation. The measurement device 100 may include
a first extension element 102, a second extension element 104, and
a base element 106. The first and second extension elements 102,104
may be rotatably and pivotably coupled to the base element 106, as
to freely move about the housing in at least two planes of motion.
The base element 106 may include a dilation indication mechanism to
measure the distance between and/or the relative movement of the
two extension elements. The dilation indication mechanism may
include one or more sensors coupled to or otherwise in
communication with the first and second extension elements 102,104.
Sensors suitable for monitoring the movement of the first and
second extension elements 102,104 may include sensors mechanically
coupled to the extension elements capable of measuring their
displacement or movement directly, including but not limited to
torque or strain gauges, or may alternatively include sensors
positioned in the tips of the first and second extension elements
that can monitor distance between the two tips via radiofrequency,
optical energy, or the like. A third sensor may be incorporated, in
the base element 106 for example, to provide increased accuracy and
precision through triangulation methods. The measurement device 100
may also include the control element 20, as previously described
and illustrated in FIG. 1, in communication with the base element
106 and one or more sensors for displaying and monitoring
information provided by the sensors.
[0050] Now referring to FIGS. 14-16, the measurement device 100 of
the present invention may also include one or more lateral sensors
108,108' positionable about the sides of the first and second
fingers used in the manual cervical dilation measurement technique.
The lateral sensors 108,108' may provide pressure feedback
information when in contact with the cervix that may assist a
physician in making a measurement while avoiding or minimizing
cervical distension. As such, the reduced likelihood of cervical
distension increases the ability to provide an accurate and precise
dilation measurement. The lateral sensors 108,108' may include one
or more thin film pressure sensors, as known in the art, to
minimize the increase in width or thickness of the device, thereby
providing ease of use and reducing discomfort of the patient, and
may further be placed in communication with the control element
20.
[0051] The measurement device 100 of the present invention may also
include one or more finger-tip pressure sensors 110,110'
positionable about the tips of the first and second fingers used in
the manual cervical dilation measurement technique. The finger-tip
pressure sensors 110,110' may indicate pressure feedback
information via the control element 20 upon contact with the head
of the baby. In addition to providing feedback information to
prevent excess pressure on the head of the baby, upon recognition
that the finger tips are indeed contacting the head of the baby, a
marker or other measurement indicator may be used to gauge the
position and descent of the baby, as described below.
[0052] Historically, practitioners have used the ischial spine as
the index point (0 station) for a determination of fetal descent,
and assigned an arbitrary number in centimeters above and below the
ischial spine. More specifically, "station" refers to the level of
the presenting fetal part in the birth canal as described in
relationship to the ischial spines, which are halfway between the
pelvic inlet and the pelvic outlet. When the lowermost portion of
the fetal presenting part is at the level of the ischial spine, it
is designated as being at zero (0) station. In the past, the long
axis of the birth canal has been arbitrarily divided into segments
for a determination of the position of the baby. Thus, as the
presenting fetal part descends from the inlet toward the pelvic
outlet, the typical designation is -5, -4, -3, -2, -1, 0 station,
+1, +2, +3, +4, +5. Using this method, the degree of accuracy (in
centimeters) is difficult to achieve clinically. In practice,
physicians may generally make an educated guess about the station
of the presenting part of the baby, since after the "0" point (0
station), the baby's head covers the ischial spine point and
eliminates the ability to measure and reproduce distance caudal to
this point. Contrary to the typical method employed, where accuracy
and precision may be difficult to maintain, the feedback from the
finger-tip sensors may provide an indication of contact with the
head of the baby. Upon such indication, a marking or other descent
indicator 112 on the portion of the hand of the physician external
to the genitalia may be used to provide an accurate and precise
measurement of the location and descent of the baby. Measurements
over the course of labor indicate rates of progression which are
practical, relatively easier to standardize and explainable to the
patient or other practitioners. This approach of measurement is
termed "Advancement".
[0053] In an exemplary use, the measurement device 100 is coupled
to the hand of a physician, with the first extension element 102
being paired to a first finger, the second extension element 104
being paired to a second finger, and the base element 106 being
positioned in between the first and second fingers. Moreover, where
the lateral sensors 108,108' or finger-tip sensors 110,110' are
included, the sensors will be positioned about the sides and tips
of the fingers, respectively, as described above. The coupling may
be achieved through the integration of the measurement device 100
with a glove 114, or through direct adhesion of the various
components to the fingers themselves. Additionally, the cervical
dilation measurement device 100 may include two cap elements
116,116' positionable about the finger tips, with the first and
second extension elements 102,104 extending from the cap elements
116,116' and towards the base element 106, and with the lateral and
finger-tip sensors coupled to the cap elements in the appropriate
positions. Any wires or other communicative elements connecting the
sensors to the control element 20 may be routed through the glove
or positioned down the back of the hand as needed to provide
connectivity while preventing interference with the use of the
device. Alternatively, the various sensors may communicate with the
control element 20 wirelessly as known in the art.
[0054] Subsequently, the physician may position the first and
second fingers and the cervical dilation measurement device 100 in
proximity to the cervix. Upon reaching the desired location, the
two fingers can be spread either into a "V" shape or an "L" shape,
and the relative movement of the first and second extension
elements 102,104 may be measured by the one or more sensors in the
base element 106, with the lateral sensors 108,108' preventing
cervical distension as previously described. As a result, the
physician will not be required to make a subjective observation as
to the actual cervical dilation, as the actual width between the
spread fingers can be accurately assessed by the cervical dilation
measurement device 100 and provided to the physician through the
control element 20. In addition, upon contacting the head of the
baby with the finger-tip sensors, the descent indicator 112 may be
referenced to determine the location of the baby.
[0055] While the method of measurement as described above may
provide an accurate and precise measurement of cervical dilation,
it is realized that different physicians may have variations in
both finger length and thickness which may affect the accuracy of
the measured dilation. Now referring to FIG. 17, the present
invention may include a calibration element 120 for use with the
measurement device 100 to compensate for the variations in the
finger dimensions of a physician. The calibration element 120 may
include an object of known dimensions, thereby providing a
reference value from which the measurement device 100 may be
calibrated. For example, the measurement device 100 may be coupled
or otherwise positioned about the hand of a physician or operator,
with the first extension element 102 being paired to a first
finger, the second extension element 104 being paired to a second
finger, and the base element 106 being positioned in between the
two fingers. Subsequently, the first and second fingers may be
extended such that an outer portion of the first and second fingers
contact a portion of the calibration element 120, providing a
"simulated" distance measurement. Upon contacting the calibration
element 120, the first and second fingers will be separated by a
known distance, and the relative movement of the first and second
extension elements 102,104 about the base element 106 can be
appropriately modified to reflect an accurate and precise
measurement. Such modification may include, for example, an
algorithm or other computational calculation taking into account
the known, fixed dimensions of the calibration element 120, the
known length of the first and second extension elements 102,104, as
well as the angle formed between them at the intersection with the
base element 106. The suggested calibration procedure may be
performed a single time for each operator who may thereafter use
the measurement device 100, and such values and calibration
modifications may be stored in the control element 20 for ease of
subsequent use without the need to re-calibrate the device.
Alternatively, the suggested calibration procedure may be performed
prior to each dilation measurement to ensure accuracy and
precision.
[0056] As discussed above, the control element 20 may be coupled to
the measurement device 100 similarly to that of the medical device
10 in order to provide a variety of information from the numerous
sensors and other components of the measurement device 100 to a
physician or operator during the above-mentioned procedures. Once
again, the control element 20 may further provide for enhanced
safety during use by including pre-determined circumstances and/or
threshold values for safe operation, irrespective of whether the
aim is to take measurements or to cause dilation. Now referring to
FIG. 18, for example, the measurement device 100 may be initially
positioned in the cervix, while values obtained from the finger-tip
sensors 110, 110' are monitored. Should a particular pressure be
experienced that exceeds a pre-determined safe operating pressure
that could damage the baby or surrounding tissue, the control
element 20 may provide an audio, visual, or tactile alarm to the
operator to withdraw the device. Upon proper positioning, the
operator or physician may expand their fingers. Subsequently,
during use of the measurement device 100, if the pressure being
exerted on the cervical tissue during expansion is greater than
desired as indicated or otherwise measured by lateral sensors 108,
108', or should the diameter of the expanded fingers as measured by
the measurement device 100 appear out of the desired range, the
control element 20 may convey these circumstances through visual,
audio or tactile indicators, upon which the physician or operator
may close and retract their fingers and the accompanying
measurement device 100.
[0057] It will be appreciated by persons skilled in the art that
the present invention is not limited to what has been particularly
shown and described herein above. In addition, unless mention was
made above to the contrary, it should be noted that all of the
accompanying drawings are not to scale. A variety of modifications
and variations are possible in light of the above teachings without
departing from the scope and spirit of the invention, which is
limited only by the following claims.
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