U.S. patent application number 17/727036 was filed with the patent office on 2022-08-04 for ablation and temperature measurement devices.
The applicant listed for this patent is Securus Medical Group, Inc.. Invention is credited to J. Christopher Flaherty, R. Maxwell Flaherty, John T. Garibotto, William J. Gorman.
Application Number | 20220240788 17/727036 |
Document ID | / |
Family ID | |
Filed Date | 2022-08-04 |
United States Patent
Application |
20220240788 |
Kind Code |
A1 |
Flaherty; J. Christopher ;
et al. |
August 4, 2022 |
ABLATION AND TEMPERATURE MEASUREMENT DEVICES
Abstract
A temperature measurement probe for a patient is provided. The
probe includes a sensor assembly and produces a temperature map
comprising temperature information for multiple patient
locations.
Inventors: |
Flaherty; J. Christopher;
(Auburndale, FL) ; Garibotto; John T.;
(Marblehead, MA) ; Flaherty; R. Maxwell;
(Auburndale, FL) ; Gorman; William J.; (South
Hamilton, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Securus Medical Group, Inc. |
Cleveland |
OH |
US |
|
|
Appl. No.: |
17/727036 |
Filed: |
April 22, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16126186 |
Sep 10, 2018 |
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17727036 |
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13988637 |
Sep 26, 2013 |
10070793 |
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PCT/US11/61802 |
Nov 22, 2011 |
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16126186 |
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61417416 |
Nov 27, 2010 |
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International
Class: |
A61B 5/01 20060101
A61B005/01; A61B 5/00 20060101 A61B005/00; A61B 18/14 20060101
A61B018/14 |
Claims
1. A temperature measurement apparatus for a patient, the apparatus
comprising: a transmission conduit configured to rotate and
translate relative to collect infrared energy from a tissue
surface; at least one infrared fiber arranged within the
transmission conduit and configured transmit infrared signals
corresponding to the collected infrared energy; and a sensor
assembly configured to process the infrared signals to calculate a
temperature of the tissue surface.
2. The apparatus of claim 1, wherein the tissue surface is an
esophagus of a patient, and the transmission conduit is configured
to rotate 360.degree. to measure an internal circumference of the
tissue surface of the esophagus.
3. The apparatus of claim 1, wherein the transmission conduit is
configured to rotate and translate in a reciprocating motion.
4. The apparatus of claim 3, wherein the transmission conduit is
configured to translate and rotate in the reciprocating motion to
collect the infrared energy across an area of the tissue surface
and the sensor assembly is configured to combine the infrared
signals collected across the area of the tissue surface and produce
a temperature map indicating the temperature within the area of the
tissue surface.
5. The apparatus of claim 1, wherein the transmission conduit
includes a lens configured to direct the infrared energy from the
tissue surface toward the at least one infrared fiber.
6. The apparatus of claim 1, wherein the at least one infrared
fiber is configured to remain stationary relative to the rotating
and translation transmission conduit.
7. The apparatus of claim 1, wherein the at least one infrared
fiber includes an infrared fiber.
8. The apparatus of claim 1, wherein the sensor assembly is
configured to continuously process the infrared signals to
calculate and update the temperature of the tissue surface.
9. A temperature measurement apparatus for a patient, the apparatus
comprising: a transmission conduit configured to rotate and
translate relative to collect infrared energy longitudinally and
circumferentially across an area of a tissue surface; at least one
infrared fiber arranged within the transmission conduit and
configured transmit infrared signals corresponding to the collected
infrared energy; a sensor assembly configured to process the
infrared signals to calculate a temperature of the tissue surface
and generate temperature information across the area of the tissue
surface; and a display unit configured to display the temperature
information.
10. The apparatus of claim 9 , wherein the temperature information
includes a temperature map indicative of a temperature of multiple
locations across the area of the tissue surface.
11. The apparatus of claim 10, wherein the sensor assembly is
configured to combine the infrared signals collected across the
area of the tissue surface and to produce the temperature map
indicating the temperature within the area of the tissue
surface.
12. The apparatus of claim 11, wherein the sensor assembly is
configured to continuously process the infrared signals to
calculate and update the temperature map.
13. The apparatus of claim 9, wherein the display unit includes a
transducer configured to alert a user in response to the
temperature information exceeding a desired temperature.
14. The apparatus of claim 13, wherein the transducer includes at
least one of an audible transducer and a visual transducer.
15. The apparatus of claim 1, wherein the at least one infrared
fiber is configured to remain stationary relative to the rotating
and translation transmission conduit.
16. The apparatus of claim 1, wherein the at least one infrared
fiber includes an infrared fiber.
17. A method of measuring temperature of an esophagus of a patient,
the method including: rotating and translating a transmission
conduit within the esophagus of the patient to collect infrared
energy from a tissue surface of the esophagus; transmitting
infrared signals corresponding to the collected infrared energy by
at least one infrared fiber arranged within the transmission
conduit; and processing the infrared signals to calculate a
temperature of the tissue surface.
18. The method of claim 17, wherein rotating and translating the
transmission conduit includes rotating and translating the
transmission conduit the reciprocating motion to collect the
infrared energy across an area of the tissue surface.
19. The method of claim 18, further comprising combining the
infrared signals collected across the area of the tissue surface
and produce a temperature map indicating the temperature within the
area of the tissue surface.
20. The method of claim 19 further comprising continuously
processing the infrared signals to calculate and update the
temperature map.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 16/126,186, filed Sep. 10, 2018, which is a continuation of
U.S. application Ser. No. 13/988,637, internationally filed May 21,
2013, which is a national stage application of PCT/US11/61802,
filed Nov. 22, 2011, which claims priority to Provisional
Application No. 61/417,416 filed Nov. 27, 2010, all of which are
herein incorporated by reference in their entireties.
TECHNICAL FIELD
[0002] Embodiments relate generally to the field of tissue
temperature monitoring, and more particularly, to ablation and
temperature measurement devices and systems that monitor tissue
temperature during energy delivery.
BACKGROUND
[0003] Ablation therapy is a medical procedure where dysfunctional
tissue is ablated using various forms of energy, typically in the
form of extreme heat or cold. Ablation therapy is utilized to treat
tumors in lung, liver, kidney, bone and in other body organs as
well as in the treatment of cardiac rhythm conditions such as
Atrial Fibrillation. Procedures are typically performed under image
guidance, such as X-ray screening, CT scan or ultrasound by an
interventional radiologist or cardiac electrophysiologist.
[0004] Although ablation treatments are useful, it is difficult to
determine with sufficient accuracy the parameters needed for
successful treatment. Inexactness in the amount of energy or
exposure time of an affected tissue may lead to thermal injury of
the adjacent healthy tissues. Catheter ablation of the heart is
particularly susceptible to such problems.
[0005] Radio-frequency (RF) catheter ablation, for example, is
commonly used to treat atrial fibrillation (AF) which is the most
common heart arrhythmia leading to hospitalization. A catheter is
inserted into a patient's heart or other vessel, and heat is
applied to a localized region until the tissue in that region has
been sufficiently destroyed to abate the arrhythmia. In other
applications, cryoablation has also been used to freeze and destroy
local tissue.
[0006] The use of extreme energy during cardiac catheter ablation
procedures for the treatment of atrial fibrillation is prone to a
serious and life-threatening complication known as atrioesophageal
fistulas. Atrioesophageal fistula after catheter ablation occurs
due to conductive heat transfer to the esophagus that causes
transmural tissue necrosis. The close proximity of the esophagus to
the posterior wall of the left atrium and the pulmonary veins
presents a significant risk of injury to the esophagus during the
application of energy to the cardiac tissue. Injury to the
esophagus resulting in tissue necrosis can create a delayed opening
in the esophageal wall, leading to the formation of a fistula
between the atrium and the esophagus. Atrioesophageal fistulas, if
not diagnosed and treated promptly, may lead to, infection and
sepsis, bleeding, air and particulate-matter emboli, stroke and
quite often death.
[0007] To date there have been no effective measures to prevent
atrioesophageal fistula formation. Various techniques are employed
to minimize the likelihood of esophageal injury during percutaneous
catheter ablation. Many physicians avoid ablating the posterior
wall of the left atrium and pulmonary veins adjacent to the
esophagus to reduce the likelihood of injury to the esophagus.
Techniques such as altering the lesion set by moving ablation lines
away from the areas adjacent to the esophagus add to the difficulty
of treating the fibrillation. Physically moving the esophagus away
from the heart wall with a luminal transesophageal echo probe is
also employed. These techniques are dependent on the specific
anatomical location of the esophagus relative to the area being
ablated. With no thermal feedback from the esophagus, the physician
has no guarantee that energy is not spreading to the esophageal
tissue. Atrial fibrillation recurrence rates are thought to be
significantly higher when these types of avoidance techniques are
employed.
[0008] Titration of energy is the most common method employed to
minimize risk of esophageal injury during percutaneous catheter
ablation. The challenge of this approach is in knowing how much
energy can be delivered before injury occurs to the esophagus.
Typically the energy that is transferred to the esophagus is
measured with a luminal esophageal temperature monitoring catheter.
These catheters are placed down the esophagus of the patient and
provide a single-point measurement of the temperature at the tip of
the catheter. The premise is that this thermal feedback will
provide the Electrophysiologist with sufficient information to
allow for the proper titration of energy and eliminate risk of
injury to the esophagus.
[0009] Several challenges limit the effectiveness of luminal
esophageal temperature monitoring devices during catheter ablation.
Studies employing luminal esophageal temperature monitoring devices
reveal that esophageal heating occurs in the range of 0.05-0.1
.quadrature.C per second and that repeated energy applications in
the same general area can cause temperature stacking. The physician
must position the temperature monitoring device adjacent to the
ablation catheter before each pulse of energy. This is very time
consuming and difficult to achieve under x-ray guidance. The
temperature monitoring catheters are very small in diameter
relative to the diameter of the esophagus. It is nearly impossible
to position the tip of the temperature probe against the esophageal
wall that is adjacent to the area of the heart wall being ablated.
Furthermore, the temperature-monitoring catheters are not designed
to be torqued or deflected toward the esophageal wall and cannot be
positioned precisely within the lumen. A recent study showed that
over 6% of patients exhibited evidence of esophageal ulceration
after catheter ablation when currently available luminal
temperature monitoring products were used and many cases of
atrioesophageal fistulas have been documented despite the use of
luminal esophageal temperature monitoring devices.
[0010] As catheter ablation for the treatment of Atrial
Fibrillation expands beyond the premier academic institutions and
into the mainstream, the limitations of today's available options
for protecting against esophageal injury will become more evident.
More physicians will be forced to make the trade-off between
sufficient ablation and the potential for damage to the patient's
esophagus. In addition to the complications related to esophageal
injury, the lack of adequate feedback will result in longer
procedure times, excess radiation exposure, and increased
arrhythmia recurrence rates.
[0011] There is a clear need for improved devices, systems and
methods to monitor temperature while actively ablating target
tissue in order to achieve the desired clinical outcome without
risk of injury to the surrounding healthy tissues.
SUMMARY
[0012] According to a first aspect, a temperature measurement probe
for a patient is provided including an elongate member and a sensor
assembly. The elongate member includes a proximal portion and a
distal portion. The probe produces a temperature map comprising
temperature information for multiple patient locations. The probe
may be side viewing, producing a temperature map for tissue
relatively orthogonal to the elongate member distal portion, such
as luminal wall tissue of a body lumen such as the esophagus.
Alternatively or additionally, the probe may be forward looking,
producing a temperature map of tissue that is positioned distal to
the distal end of the elongate member.
[0013] The elongate member distal portion may be configured for
insertion within the body of the patient, such as a patient lumen
such as an insertion into the esophagus of a patient during a
cardiac ablation procedure. The elongate member proximal portion
may comprise a connector such as an electrical connector and/or a
fiber optic connector. The elongate member may comprise a thermos
construction along at least a portion of its length, such as to
minimize the effects of stray infrared radiation not emanating from
the multiple patient locations.
[0014] The sensor assembly may comprise a non-contact sensor
assembly constructed and arranged to measure temperature without
making physical contact with the multiple patient locations. The
sensor assembly may be configured to be side viewing and/or forward
viewing. The sensor assembly may comprise a sensor type selected
from the group consisting of: infrared detector or other infrared
sensor such as a passive or active infrared sensor; thermocouple,
thermopile such as a bolometer, thermister, thermochromic element,
pyrometer, liquid crystal such as thermotropic liquid crystals; and
combinations of these. The sensor assembly may be configured to
detect a non-temperature change, such as a non-temperature change
in the multiple tissue locations that can be correlated to an
absolute temperature or a relative temperature (e.g. a temperature
change). Typical detected non-temperature tissue changes include
but are not limited to: color changes; cellular structure changes
such as cellular wall expansion; conductivity changes; density
changes; and combinations of these. The sensor assembly may be
constructed and arranged to detect one or more substances produced
by tissue, such a sensor configured to detect the substance through
monitoring of one or more of: a color change; detection of the
produced substance; detection of a substance produced during cell
death; detection of a substance produced during cell damage;
detection of an emitted gas; and detection of smoke.
[0015] The sensor assembly may include an array of sensors such as
an array of passive and/or active infrared sensors. At least a
portion of the sensor assembly may be included in the distal
portion of the elongate member in relative proximity to the tissue
to be measured, such as a sensor assembly comprising a rotating
mirror. Alternatively or additionally, at least a portion of the
sensor assembly may be located in a more proximal location, such as
in the proximal portion of the elongate member, in a handle of the
probe, and/or in a separate device that is electrically or
optically coupled to the probe. In one embodiment, the sensor
assembly includes infrared light detectors that receive infrared
radiation that is directed proximally from the elongate member
distal portion by a series of lenses and mirrors.
[0016] At least a portion of the sensor assembly may be rotated,
such as a continuous 360.degree. rotation to measure a full
circumferential wall portion of luminal tissue. Partial rotations
may be performed such as rotations of at least 90.degree.; at least
180.degree.; no more than 180.degree.; and combinations of these.
Rotations may be back and forth in a reciprocating motion (e.g.
clockwise followed by counter clockwise rotations). At least a
portion of the sensor assembly may be moved axially, such as to
translate in a reciprocating back and forth motion, and the
received information combined such as to produce a temperature map
of a particular length of tissue that is longer than the sensor
assembly. In one embodiment, at least a mirror and a fiber optic
are translated in a reciprocating motion. In one embodiment, the
sensor assembly is configured to measure the temperature of one
patient location at a time. In this configuration, at least a
portion of the sensor, such as a mirror, may be configured to
rotate and/or translate to gather temperature information from
multiple patient locations. Alternatively or additionally, a lens
may be configured to move or change shape to gather the multiple
patient location temperature information. Alternatively or
additionally, the mirror may be configured to change shape to
gather the multiple patient location temperature information.
[0017] In one embodiment, the probe includes a second sensor
assembly, such as a sensor assembly with a different construction
than the first sensor assembly. The second sensor assembly may be
an array of sensors, such as an array of infrared light detectors
or other infrared sensors.
[0018] In one embodiment, the sensor assembly comprises an array of
sensors, such as an array of spinning sensors configured to rotate
at least 90.degree. The array may be a linear array, such as a
linear array with a length of at least 2'' or a length of at least
3''. The sensor assembly may include a lens, such as a lens
configured to focus light such as infrared light energy on the
array of sensors.
[0019] In one embodiment, at least a portion of the sensor assembly
is positioned in the elongate member distal portion. This sensor
array portion may be configured to spin and/or translate. This
sensor array portion may include an integrated circuit, such as an
integrated circuit including components selected from the group
consisting of: multiplexing circuitry components; infrared
detectors; rotational movement encoding components; translational
movement encoding components; and combinations of these. The sensor
array portion may include a lens, such as an infrared transparent
lens. The sensor assembly may comprise a transmission conduit
traveling from the sensor assembly portion to the elongate member
proximal portion. The transmission conduit may be configured to
transmit energy and/or data, and may include one or more optical
fibers and/or one or more electrical wires.
[0020] In one embodiment, at least a portion of the sensor assembly
is not positioned in the elongate member distal portion, such as a
sensor assembly portion located in the elongate member proximal
portion and/or proximal to the elongate member, such as in a
separate device. In this embodiment, one or more lenses may be
positioned in the elongate member distal portion, such as with an
orientation towards tissue whose temperature is to be measured. A
transmission conduit may be positioned between the elongate tube
distal portion and the sensor assembly portion, such as a
transmission conduit including a hollow tube with a lens and/or
mirror positioned at or proximate to its distal end. The
transmission conduit may be a solid cylinder, such as a cylinder
comprising a single fiber or a bundle of fibers. The transmission
conduit may be flexible, and it may be configured to rotate and/or
translate. A probe with at least a sensor assembly portion not
positioned in the elongate tube distal portion may include one or
more mirrors constructed and arranged to deflect radiation such as
infrared radiation toward the proximal portion of the elongate
tube. The mirror may be constructed and arranged to move, such as
to rotate and/or translate.
[0021] The sensor assembly may include at least one optical fiber,
such as a single infrared transparent fiber, or multiple fibers
such as multiple infrared fibers in a coherent or non-coherent
bundle. Fibers may be constructed of material selected from the
group consisting of: germanium; arsenic; selenium; sulfur;
tellurium; silver halide; or other materials knows to offer little
or no impedance to transmission of infrared light.
[0022] The multiple patient locations may comprise a continuous
area of tissue surface, or multiple areas such as multiple discrete
points. The multiple patient locations may comprise a relatively
uni-planar surface (e.g. a relatively flat surface), or it may
comprise a multi-planar surface such as a round surface such as the
luminal wall of the esophagus or a surface with numerous bumps,
ridges, grooves and/or walls, such as the topography inside the
lung.
[0023] The probe may include a membrane, such as a membrane
surrounding at least a portion of the sensor assembly. One or more
sensors may be positioned on the membrane, and the membrane may be
inflatable. The membrane may comprise the sensor.
[0024] The probe may include or otherwise be electronically
attachable to a display unit used to display the temperature
information, as well as one or more other user output components
such as audible transducers, tactile transducers, and other visible
transducers such as LEDs and alphanumeric displays. The probe may
include signal processing means such as to convert temperature
information to color maps such as color maps representing different
temperature through differences in color, shade, hue, boldness of
text, text font, font type, font size, and the like. Signal
processing may mathematically process the temperature information
such as to determine maximums, averages, integrations of time at
temperature, and the like. The probe may include zooming and
panning functions such as automatic zooming and panning functions.
In one embodiment, the temperature map provided is zoomed (in or
out) or panned based on temperature information shown on this
display or information outside of the temperature map that is
currently being displayed. The probe may include a feedback circuit
used to modify a probe component such as a display or a tissue
temperature modifying assembly, or another component such as an
energy delivery unit. The display may include the energy delivery
unit, and the display may be configured to provide both tissue
temperature information and energy delivery information.
[0025] An attached display may provide temperature and other
information in one or more forms. Temperature information may be
displayed in non-numeric forms, such as by displaying temperature
level information as represented by one or more of: color; shade;
hue; saturation; and brightness. Additionally or alternatively,
numeric temperature information may be included, such as
information representing current temperature; an average of
temperature over time; peak or maximum temperature over time; a
representation of historic temperature information; and
combinations of these. The display may be configured to allow an
operator to adjust a domain of values of the displayed temperature
map, such as to correlate a display property such as color to a
particular temperature or temperature range. Temperature
information can be displayed on a representation of tissue being
measured, such as an actual image or artistic rendering of the
esophagus when the multiple patient locations comprise locations
within the patient's esophagus. Other information may be provided
on the display, such as information selected from the group
consisting of: a timestamp; a patient ID; a clinician ID; a
location such as a location where the procedure was performed;
information about the anatomical location of the multiple patient
locations; EKG information; energy delivered information; patient
physiologic information; and combinations thereof. A user interface
may be included, such as to allow an operator to adjust a
temperature range, or a correlation of colors to a temperature map.
A user interface may be configured to allow an operator to adjust a
focus, such as the focus of at least a portion of the probe onto
tissue, such as to collect infrared light in a focused manner.
[0026] The probe may include an alert element, such as an alert
element with adjustable alert parameters. The alert may be
activated based on one or more of: information included in the
currently provided temperature map; cumulative temperature
information collected over time; and combinations of these. The
alert may comprise an element selected from the group consisting
of: an audible transducer; a visual transducer; a tactile
transducer; and combinations of these.
[0027] The probe may include a malleable member, such as a
malleable member included along at least a portion of the length of
the elongate member and configured to allow an operator to
plastically deform the elongate member to a desired two or three
dimensional shape.
[0028] The probe may include one or more lumens, such as one or
more lumens extending from the elongate member proximal end or
other proximal portion to the elongate member distal end or other
distal portion. The one or more lumens may be configured as an
inflation lumen, such as to inflate a balloon or other expandable
device positioned on or in the elongate member, or the one or more
lumens may be configured as a fluid delivery lumen such as to
deliver one or more cooling or other fluids to the elongate member
distal portion or tissue proximate the elongate member distal
portion.
[0029] The probe may include one or more cleaning elements, such as
an element used to wash or wipe debris from one or more lenses of
the probe. The cleaning element may comprise a wiper, such as a
wiper configured to move across one or more portions of the sensor
assembly, such as across a lens of the sensor assembly. The
cleaning element may be constructed and arranged to move in a back
and forth, reciprocating motion. The cleaning element may be
removable.
[0030] The probe may include a cleaning assembly, such as an
assembly constructed and arranged to deliver fluid toward the
elongate member distal portion, such as to deliver fluid to a lens
mounted to the distal portion, such as to remove mucus or other
bodily fluids from the probe. The cleaning assembly may include one
or more cleaning members, such as a first and a second cleaning
member used to sequentially clean at least a portion of the probe.
The probe may include a second cleaning assembly, where the second
cleaning assembly can be similar or dissimilar to the first
cleaning assembly.
[0031] The probe may include one or more positioning members to
position the sensor assembly or other probe component at a
predetermined distance from the tissue to be measured. The
positioning members may be configured to position a portion of the
probe, such as at least a portion of the sensor assembly, to a
particular location or orientation relative to the multiple tissue
locations. In one embodiment, the positioning members are
configured to center a portion of the probe in a lumen, such as to
center in a segment of the esophagus. Alternatively or
additionally, the positioning members may be configured to position
the portion of the probe at an off-center location, such as near a
portion of a lumen wall relatively on the opposite side of the
portion of the luminal wall comprising the multiple patient
locations. The positioning elements may be positioned proximal
and/or distal to the sensor assembly. The positioning elements may
comprise one or more of a balloon and an expandable cage.
[0032] The probe may include one or more tissue tensioning members
used to modify the topography of the tissue to be measured, such as
to remove or reduce a fold or divot, such as a fold or divot in
esophageal tissue. The tissue tensioner may be a deployable element
such as a balloon, stent, or opposing arms or fingers. At least a
portion of the tissue tensioner may comprise a shaped memory
material such as Nitinol. Multiple tissue tensioners may be
included. A sensor may be positioned in, on and/or proximate to a
tissue tensioner. The tissue tensioner may be configured to
radially and/or axially tension tissue.
[0033] The probe may include a luminal expander, such as to expand
luminal wall tissue such as esophageal wall tissue. The luminal
expander may be configured to expand tissue with a gas such as air
or carbon dioxide and/or a liquid such as saline.
[0034] The probe may include a tissue temperature modifying
assembly, such as an assembly to warm or cool tissue that has
reached an undesired temperature, such as one or more segments of
the multiple patient locations. The temperature modifying assembly
may comprise substances configured to be operably activated to
cause an endothermic reaction to occur, such as to cool tissue
during a cardiac heat ablation procedure. Alternatively, the
temperature modifying assembly may comprise substances configured
to be operably activated to cause an exothermic reaction to occur,
such as to warm tissue during a cardiac cryo ablation procedure.
The temperature modifying assembly may be configured to spray a
fluid, such as a cool fluid onto tissue. The temperature modifying
assembly may comprise one or more pettier components constructed
and arranged to cool at least a portion of the probe, such as tool
cool tissue proximate the probe.
[0035] The probe may include a probe temperature modifying assembly
constructed and arranged to modify and/or maintain the temperature
of at least a portion of the probe. The probe temperature modifying
assembly may be configured to cool or warm a portion of the probe,
such as with circulating fluid. The probe temperature modifying
assembly may comprise at least two coaxial tubes, such as two tubes
surrounding one or more optical fibers and constructed and arranged
to produce a thermos effect within the inner tube. The probe
temperature modifying assembly may be configured to maintain the
temperature of one or more electronic components, such as one or
more electronic components positioned in the distal portion of the
elongate member. The probe temperature modifying assembly may
comprise a peltier component.
[0036] The probe may include an iso-thermal assembly constructed
and arranged to cause at least a portion of the probe to tend to
avoid temperature changes. The iso-thermal assembly may comprise
one or more of: a thermos design; circulating fluid such as
circulating fluid maintained at a relative constant temperature or
circulating fluid whose temperature changes based on one or more
measured temperatures of a portion of the probe; an assembly
positioned proximate to at least a portion of the sensor assembly;
an assembly positioned proximal to at least a portion of the sensor
assembly; and an assembly positioned distal to at least a portion
of the sensor assembly.
[0037] The probe may include an imaging device, such as an
ultrasound imaging device or a visible light camera. Images from
the imaging device may be provided on a display.
[0038] The probe may include a temperature sensor, such as a
thermocouple or other temperature sensor positioned on the elongate
member, such as on the distal portion of the elongate member.
[0039] The probe may include one or more markers such as radiopaque
markers.
[0040] The probe may include one or more functional elements used
to perform a medical procedure, such as a therapeutic or
reconstructive procedure. Typical functional elements include but
are not limited to: an electrode; a drug delivery element; an
electromagnetic element; a heating element; a cooling element such
as a peltier component; and combinations of these. One or more
functional elements may be positioned on the distal portion of the
elongate member, such as on or in a distal tip of the probe. The
sensor may be oriented forward, along the axis of the distal
portion, or may be side oriented, orthogonal to the axis of the
distal portion. One or more functional elements may comprise one or
more thermocouples, such as one or more thermocouples used to
calibrate the probe and/or the sensor assembly.
[0041] The probe may include a signal analyzer, such as a signal
analyzer that provides information based upon signals received from
at least the sensor assembly. The signal analyzer may provide
maximum temperature information. The signal analyzer may provide
information based on a tissue location selected by an operator of
the probe. The signal analyzer may include an alert assembly, such
as an alert assembly configured to alarm and/or adjust an energy
delivery. The alert assembly may be clinician adjustable or
programmable, such as adjustable to adjust levels of temperature
thresholds and/or temperature rise thresholds. The signal analyzer
may compare temperature information to a library of data, such as a
library including a safety map of data. The signal analyzer may
compare the largest of multiple temperature readings to a
threshold. The signal analyzer may create a histogram of
temperature data. The signal analyzer may provide image
stabilization, such as image stabilization based on signals
received from a sensor of the probe, such as an accelerometer
mounted in the distal portion of the elongate member. The signal
analyzer may be configured to automatically zoom into or away from
an area, such as an area provided on a video display. The automatic
zoom may be triggered by temperature information, such as a zoom-in
function triggered by one or more temperatures above a threshold in
a particular portion of the multiple patient locations. A zoom-out
function may be triggered when a temperature is achieved at a
location outside of the currently displayed tissue portion, such as
to include the location at which the above-threshold temperature
occurs. The signal analyzer may be configured to provide a panning
function.
[0042] The probe may include a memory storage module, such as a
memory storage module configured to store time versus temperature
map information. The memory module may store information selected
from the group consisting of: video information; alpha-numeric
information; and combinations of these.
[0043] The probe may include an error detection assembly, such as
an error detection assembly configured to alarm if a temperature
outside of an expected range is detected. The error detection
assembly may be further configured to compensate for outlier data,
wherein an alarm state is avoided if an outlier is suspected or
confirmed.
[0044] The probe may include a calibration assembly, such as a
calibration assembly configured to perform a calibration on the
sensor assembly and/or another component or assembly of the probe.
The calibration assembly may comprise a calibration algorithm or
other subroutine which utilizes information received from the
calibration assembly. The calibration assembly may comprise a
calibration standard.
[0045] The probe may include a sterility barrier, such as a
sterility barrier positioned about at least the distal portion of
the elongate member.
[0046] The probe may be further constructed and arranged to produce
a second map comprising non-temperature information from the
multiple patient locations. The non-temperature information may
comprise visual and/or ultrasound images of the multiple patient
locations.
[0047] The probe may include an audible transducer. In one
embodiment, the sound created by the audible transducer varies and
correlates to temperature information. Sound variations may
correlate to one or more of: an average of temperature readings; a
maximum of temperature readings; a minimum of temperature readings;
and an integration of temperature readings over time.
[0048] The probe may include a visible transducer such as a light
emitting diode (LED).
[0049] The probe may include a feedback circuit, such as a feedback
circuit used to control an energy delivery unit, such as a
radiofrequency energy delivery unit or a cryo ablation energy
delivery unit. The feedback circuit may be configured to modify
energy delivery, such as to reduce or stop energy delivery. The
feedback circuit may be configured to prevent energy delivery, such
as to prevent energy delivery if the feedback circuit is off or
otherwise detecting an undesired temperature condition. The
feedback circuit may be configured to control a tissue and/or probe
cooling assembly, such as to activate the cooling assembly when one
or more temperature measurements are above a threshold. The
feedback circuit may be configured to control a tissue and/or probe
warming assembly, such as to activate a warming assembly when one
or more temperature measurements are below a threshold.
[0050] The probe may comprise a lens assembly, such as a lens
assembly configured to focus or otherwise direct infrared light
onto one or more infrared detectors or other infrared sensors. The
lens assembly may comprise one or more lenses, such as an inner
lens and an outer lens.
[0051] The probe may comprise a noise reduction algorithm, such as
to reduce infrared noise or other thermal noises. The noise
reduction algorithm may be configured to reduce or otherwise filter
one or more predetermined sources of noise, such as one or more
predetermined sources of infrared radiation.
[0052] The probe may include one or more tools, such as one or more
tools selected from the group consisting of: energy delivery
elements such as radiofrequency electrodes; lasers; ultrasonic
crystals; saws; drills; electrocautery devices; coagulators;
laparoscopic tools; and combinations of these.
[0053] According to another aspect, a system including a
temperature monitoring probe in accordance with the present
inventive concepts and a laparascopic tool is provided. The probe
sensor assembly may be positioned on and/or in, or otherwise
integrated into the laparascopic tool. The probe elongate member
may comprise the shaft of the laparoscopic tool.
[0054] According to another aspect, a system including a
temperature monitoring probe in accordance with the present
inventive concepts and a bone cutter is provided. The bone cutter
may comprise a drill and/or a saw. The probe's multiple patient
locations may comprise tissue being cut and/or tissue proximate the
tissue being cut.
[0055] According to another aspect, a system including a
temperature monitoring probe in accordance with the present
inventive concepts and an energy delivery assembly is provided. The
energy delivery assembly may be configured to deliver energy
selected from the group consisting of: laser energy; radiofrequency
energy; cryogenic fluid energy; microwave energy; mechanical
energy; chemical energy; electromagnetic energy; and combinations
of these. The energy delivery assembly may be positioned in the
probe's elongate member distal portion, such as at, on or near the
probe's distal end. The probe's multiple patient locations may
comprise tissue to which energy is being delivered and/or tissue
proximate the tissue receiving the energy.
[0056] According to another aspect, a system including a
temperature monitoring probe in accordance with the present
inventive concepts and a magnetic resonance imaging (MRI) device is
provided. The probe is constructed and arranged to detect heat
produced during an MRI imaging procedure, such as heat occurring at
or proximate to one or more ferromagnetic material in, on or near
the patient being imaged.
[0057] According to yet another aspect, a method of producing a
temperature map comprising temperature information for multiple
patient locations is disclosed. A probe is provided including a
sensor assembly and an elongate member. The elongate member
includes a proximal portion and a distal portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate various
embodiments of the present inventive concepts, and together with
the description, serve to explain the principles of the inventive
concepts. In the drawings:
[0059] FIG. 1 illustrates a schematic view of a system including a
temperature measurement probe, consistent with the present
inventive concepts;
[0060] FIG. 2A illustrates a side view of a clinical procedure
including an ablation catheter and an esophageal temperature probe,
consistent with the present inventive concepts;
[0061] FIG. 2B illustrates a side sectional view of the esophageal
temperature probe of FIG. 2A, consistent with the present inventive
concepts;
[0062] FIG. 2C illustrates a magnified side sectional view of the
temperature probe of FIG. 2B, consistent with the present inventive
concepts;
[0063] FIGS. 3A and 3B illustrate side and end sectional views,
respectively, of the distal portion of an ablation and forward
viewing temperature measurement probe, consistent with the present
inventive concepts;
[0064] FIG. 4A illustrates a side sectional view of an elongate
member of a side viewing temperature probe with a translating
sensor, consistent with the present inventive concepts;
[0065] FIG. 4B illustrates a side sectional view of the temperature
probe of FIG. 4A, with the sensor advanced, consistent with the
present inventive concepts;
[0066] FIG. 5 illustrates a side sectional view of the distal
portion of a side viewing temperature probe with a rotating array
of sensors, consistent with the present inventive concepts;
[0067] FIG. 6 illustrates a side sectional view of the distal
portion of a side viewing temperature probe with a fiber bundle
with beveled end, consistent with the present inventive
concepts;
[0068] FIG. 7 illustrates a side sectional view of the distal
portion of a side viewing temperature probe with a sensor array
attached to a shaft, consistent with the present inventive
concepts;
[0069] FIG. 8 illustrates a side sectional view of the distal
portion of a side viewing temperature probe with a fiber bundle and
end-mounted focusing lens, consistent with the present inventive
concepts;
[0070] FIGS. 9A and 9B illustrate side and end sectional views,
respectively, of an ablation and forward viewing temperature
measurement probe including an array of optical fibers and a tip
electrode, consistent with the present inventive concepts;
[0071] FIG. 10 illustrates a side sectional view of a side viewing
temperature probe with a thermos construction, consistent with the
present inventive concepts;
[0072] FIG. 11 illustrates a side view of a temperature probe with
an array of surface sensors, consistent with the present inventive
concepts;
[0073] FIG. 12 illustrates a schematic view of a system including
an ablation and forward viewing temperature measurement probe and
an energy delivery unit, consistent with the present inventive
concepts;
[0074] FIG. 13 illustrates a side sectional view of the distal
portion of a side viewing temperature probe including positioning
arms, consistent with the preset inventive concepts;
[0075] FIG. 14 illustrates a side sectional view of the distal
portion of a side viewing temperature probe including fluid
delivery ports, consistent with the present inventive concepts;
[0076] FIG. 15A illustrates a side view of the distal portion of a
side viewing temperature measurement probe with a cleaning wiper,
consistent with the present inventive concepts;
[0077] FIG. 15B illustrates the temperature measurement probe of
FIG. 15A with the cleaning wiper advanced, consistent with the
present inventive concepts;
[0078] FIG. 16 illustrates a side sectional view of the distal
portion of a side viewing temperature measurement probe with a
cleaning fluid delivery port; consistent with the present inventive
concepts;
[0079] FIG. 17 illustrates a side sectional view of the distal
portion of a side viewing temperature measurement probe with a
detachable portion including lens, mirror, cooling chamber and
sensors, consistent with the present inventive concepts;
[0080] FIG. 18 illustrates a flow chart of a data analysis and
processing function for a temperature measurement probe, consistent
with the present inventive concepts;
[0081] FIG. 19 illustrates a side view of the distal portion of a
side viewing temperature probe with a disposable portion including
an outer sheath and positioning arms, and a reusable portion
including a sensor assembly.
DETAILED DESCRIPTION
[0082] Reference will now be made in detail to the present
embodiments of the inventive concepts, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers will be used throughout the drawings to
refer to the same or like parts.
[0083] Provided herein is a temperature measurement probe for
producing a temperature map for multiple locations, such as a
surface of tissue for a patient. The probe may include one or more
sensors, such as infrared light detectors or other infrared
sensors. The probe may include a reusable portion, and one or more
disposable portions. The probe may include an elongate member, and
measure temperature at multiple locations positioned at the side of
the elongate member and/or forward of the distal end of the
elongate member.
[0084] Referring now to FIG. 1, a system of the present inventive
concepts is illustrated. System 10 includes luminal temperature
measurement device 100, electronic module 150, and display 155.
Device 100 may be configured to be placed into a patient, such as
into a lumen within the body of a patient. System 10 is configured
to produce a temperature map of multiple patient locations. Typical
patient locations include but are not limited to: one or more
continuous tissue areas, multiple discrete locations, one or more
locations on a single plane or two or more locations on multiple
planes. Device 100 includes shaft 110 which includes connector 111
at its proximal end. Shaft 110 may be rigid, flexible, or include
both rigid and flexible portions. Device 100 is attached to
electronic module 150 via cable 112. Cable 112 may be configured to
perform one or more functions, including but not limited to:
providing power or transmitting a force; sending or receiving
electrical signals such as via wires; sending or receiving optical
signals such as via fiber optic cables; transmitting acoustical
signals such as sound waves; and transmitting solids, liquids or
gases such as via one or more lumens.
[0085] Sensor assembly 120 is positioned at the distal end of shaft
110 and is configured to provide temperature information for
multiple patient locations, such as multiple tissue locations. In
one embodiment, sensor assembly 120 is configured to gather,
measure and/or process infrared signals to determine temperature
information, such as when device 100 comprises a passive or active
infrared detector or detector array. Sensor assembly 120 may
comprise a lens assembly such that infrared or other energy can be
directed toward a sensor located at another location in device 100
and/or electronic module 150. Typical sensors used to measure the
temperature information include but are not limited to: infrared
sensors such as active or passive infrared sensors or sensor
arrays; thermocouple or thermocouple arrays, thermopiles such as a
bolometer; therm isters; thermochromic elements; pyrometers; liquid
crystal temperature detectors such as thermotropic liquid crystals;
fluorescent sensors; and sensors including leuco dyes and
combinations of these.
[0086] Alternatively or additionally, device 100 and sensor
assembly 120 are configured to detect a non-temperature tissue
change, such that system 10 can process this tissue change
information to produce a temperature map for multiple patient
locations. These tissue changes include but are not limited to:
tissue color changes; cellular structure changes such as cellular
expansion; tissue conductivity changes; tissue density changes; and
combinations of these. These non-temperature signals may correlate
to an absolute temperature of tissue or a change in temperature of
tissue.
[0087] Alternatively or additionally, device 100 and sensor
assembly 120 are configured to detect a substance produced by
tissue, such that system 10 can process this substance production
information to produce a temperature map for multiple patient
locations. Substance production information may include but are not
limited to: one or more substances associated with cellular damage;
gas production; smoke production; and combinations of these.
[0088] Sensor assembly 120 may include various optical components
to focus, transmit, split, reduce, filter, communicate or otherwise
handle light such as infrared light. Typical components include but
are not limited to: lenses; mirrors; filters; fiber optic cable;
prisms; amplifiers; refractors; splitters; polarizer; and other
optical components well known to those of skill in the art. In one
embodiment, optical components focus infrared light on a sensor or
sensor array integral to sensor assembly 120. The one or more
optical components may be fixedly mounted in device 100 or may be
moved such as with rotational, translational, reciprocal, orbital
and/or other movement assemblies such as MEMS assemblies.
[0089] Sensor assembly 120 provides temperature information to
electronic module 150. This information may be transmitted by one
or more conductors such as wires or fiber optic cables, or may be
transmitted wirelessly. In a particular embodiment, sensor assembly
120 provides temperature information in the form of infrared light
which is transmitted through shaft 110 (e.g. deflected with a
series of mirrors) to an infrared sensor array in a proximal
portion of device 100 and/or within electronic module 150. In
another embodiment, sensor assembly 120 is connected to a fiber
optic cable, such as a cable that is of low impedance or
transparent (zero impedance) to infrared light or a band of
infrared light, and connected to a lens or other optical component
assembly which directs the infrared light to an infrared sensor
array in a proximal portion of device 100 and/or within electronic
module 150. In yet another embodiment, sensor assembly 120 includes
an infrared sensor array, and one or more electrical conductors
such as wires travel proximally in shaft 110 and communicate
temperature information to electronic module 150.
[0090] Device 100 may include a visible light camera constructed
and arranged to provide a visible picture of one or more patient
locations, such as one or more locations in the patient's
esophagus. In a particular embodiment, a visible light picture is
provided on display 155 of the same or similar multiple patient
locations that are recorded by sensor assembly 120.
[0091] Proximate sensor assembly 120 is port 116, such as a port
configured to deliver fluid to sensor assembly 120 or tissue
proximate sensor assembly 120. Shaft 110 may include one or more
lumens, not shown but fluidly or otherwise operably connected to
cable 112, port 105a or port 105b, such as to provide inflation
fluid such as to inflate a balloon, to deliver one or more agents
such as a cooling or warming fluid or a drug to port 116, or to
slidingly receive a fiber or fiber bundle such as a cable linkage,
an optical fiber or fiber bundle, or a conductor or conductor
bundle.
[0092] Device 100 may include one or more functional elements, such
as functional element 160 located proximate sensor assembly 120.
Functional element 160 is typically a sensor or a transducer, such
as an element selected from the group consisting of: an electrode;
a drug delivery element; an electromagnetic transducer; a heating
or cooling element; and combinations of these. Functional element
160 may be a sensor, such as a thermocouple or other temperature
sensor. In a particular embodiment, functional element 160 is a
temperature sensor configured to be used in a calibration of sensor
assembly 120.
[0093] Located at the proximal end of shaft 110 are ports 105a and
105b. Ports 105a and 105b are operably connected to one or more
lumens of shaft 110, not shown but preferably providing a
connection to one or more locations along shaft 110, such as port
116, functional element 160 and/or sensor assembly 120. Ports 105a
and/or 105b may be attachable to a fluid delivery device, such as
an infusion pump or a syringe, such that fluid such as saline can
be used to clean a portion of device 100, heat or warm tissue
proximate sensor assembly 120, and/or provide another function.
[0094] Device 100 may include one or more stabilization portions,
not typically located near the proximal end of shaft 110 or along
cable 112 and configured to position and/or prevent undesired
motion of device 100. Typical stabilization portions may include a
clip, a mouth piece such as a mouth piece used to position shaft
110 in the esophagus of the patient, a vacuum assembly, and
combinations of these.
[0095] Electronic module 150 receives signals from sensor assembly
120 of device 100. These signals represent a temperature map of
multiple patient locations in proximity to sensor assembly 120.
Sensor assembly 120 may produce electrical signals such as signals
received from electronics integral to sensor assembly 120, not
shown but preferably electronics common to visible light and
infrared camera products. Alternatively or additionally, the
signals may be optical signals such as infrared signals received
from sensor assembly 120 and transmitted via optical fibers
included in shaft 110 and cable 112. In one embodiment, connector
111 may include an electronic assembly which converts optical
signals to electrical signals, such as when connector 111 receives
optical signals from a fiber bundle contained within shaft 110, and
transmits electrical signals to electronic module 150 through wires
in cable 112.
[0096] Electronic module 150 processes the signals received from
sensor assembly 120 to produce information representing a
temperature map of the multiple patient locations viewed by sensor
assembly 120. The temperature information may be presented on
display 155 such as via signals transmitted through cable 113 such
that temperature map 156 is shown on display 155. Alternatively or
additionally, temperature information may be transmitted to display
155 via a wireless transceiver. Temperature map 156 may be
presented in a number of forms including but not limited to a
tabular display of alphanumeric values representing the temperature
of the multiple patient locations, or a graphical picture such as a
color picture in which temperatures are represented by color shades
or hues.
[0097] Electronic module 150 may include alarm transducer 157, such
as a transducer selected from the group consisting of: an audible
transducer, a visible transducer such as a light emitting diode
(LED), a tactile transducer, or other element configured to alert
an operator of a condition such as an alarm, alert, warning, or
other condition (hereinafter "alarm") in which an operator of the
system is to be notified. Module 150 may process the information
received from sensor assembly 120 to determine when a condition
exists in which alarm transducer is to be activated. Alarm
conditions may be adjustable, such as via a user interface, not
shown, but integral to electronic module 150 or another component
of system 10. In one embodiment, the condition is determined by
comparison to a threshold, such as a threshold adjustable by an
operator of system 10. Alarm conditions may be based on the current
temperature map and/or a cumulative or other mathematically
processed representation of values of the temperature map such as
cumulative historic values of multiple patient locations. In a
particular embodiment, system 10 provides current and historic
temperature information for multiple patient locations, the
information including but not limited to: current temperature;
average temperature; maximum temperature; minimum temperature;
slope of temperature change; and integration of temperature over
time. The various types and forms of recorded and calculated
temperature information can be presented to the operator via
display 155, another display or memory component. Alternatively or
additionally, the various types and forms of recorded and
calculated temperature information can be compared to one or more
alarm thresholds such as to activate alarm transducer 157. In a
particular embodiment, when an alarm condition is entered, system
10 or a separate system may be controlled by system 10, such as to
cease power delivery when a maximum temperature is achieved.
[0098] Electronic module 150 may include a memory storage module,
such as a module configured to store temperature and/or other types
of information including but not limited to: historic information
such as temperature versus time information, pre-determined
threshold information such as information related to maximum
temperatures allowable for a particular tissue or tissue type,
calculated information such as an integration of time at
temperature for a tissue location; calibration information such as
historic calibration information and data used to perform a
calibration procedure; alarm information such as historic alarm
conditions or data used to determine when system 100 has entered an
alarm state; and other information.
[0099] Electronic module 150 may include a signal analyzer, such as
a signal analyzer which may be used or modified by the operator.
Inputs and outputs of the signal analyzer may be shown on display
155, such as in displaying temperature information for a particular
tissue location. The signal analyzer may allow zooming, such as to
zoom into a particular site of tissue, and the site location may be
manipulated by the operator, such as through a user interface (not
shown).
[0100] System 10 may include visualization instrument 210, such as
a visualization instrument selected from the group consisting of:
an MRI, a Ct scanner, a fluoroscope or other x-ray instrument; and
combinations of these. In one embodiment, visualization instrument
210 is an MRI, and system 10 is used to detect heat, such as
undesired heat, caused by the interaction between an MRI and one or
more pieces of metal implanted in a patient.
[0101] Alternative or in addition to device 100, system 10 includes
tool 300 which is connected to electronic module 150 via cable 301.
Tool 300 includes sensor assembly 320, a forward looking infrared
sensor assembly configured to visualize multiple patient locations,
such as a surface of bone or other tissue being treated by tool
300. Tool 300 may be a tool selected from the group consisting of:
a laparoscopic tool such as a laparoscopic radiofrequency (RF)
energy ablation tool; a bone cutting tool such as a bone cutting
saw; a drill; and combinations of these. In a typical application,
the multiple patient locations is bone being drilled or cut into,
and system 10 is configured to prevent overheating of patient
tissue.
[0102] System 10 typically includes both disposable and reusable
components. In one embodiment, device 100 including shaft 110,
sensor assembly 120, and cable 112 are disposable (e.g. used for a
single patient procedure only), while electronic module 150 and
display 155 are reusable. In another embodiment, cable 112 is
reusable. In another embodiment, a disposable sheath surrounds a
reusable device 100 including reusable shaft 110 and reusable
sensor assembly 120.
[0103] Referring now to FIG. 2A, a method of the present inventive
concepts is illustrated in which a patient is receiving an ablation
procedure, such as a cardiac ablation procedure to treat atrial
fibrillation (AF). Ablation catheter 253 is inserted into the
vasculature of the patient and advanced to patient P's heart. An
energy delivery unit, not shown, connects to catheter 253 such that
catheter 253 delivers ablation energy to patient P's heart.
Ablation is typically achieved by heating or cooling tissue (e.g.
left atrial or right atrial tissue) through the use of
radiofrequency (RF) energy; laser energy; cryogenic energy;
subsonic energy; acoustic energy; ultrasound energy; microwave
energy; chemical energy; and combinations of these.
[0104] System 10 includes device 100 which has been inserted into
the esophagus of patient P by a clinician. System 10 includes
display 155 which provides temperature map 156 of multiple
locations within patient P's esophagus. Temperature map 156 and
other information provided on display 155 or another display device
(not shown), may utilize various alphanumeric or other graphical
properties to differentiate temperature or other information. In a
preferred embodiment, different temperatures are differentiated
through the change in one or more of: color; shade; contrast; hue;
saturation; and brightness. Alternatively or additionally,
alphanumeric information may be differentiated by varying one or
more of: boldness; font type and size. Information such as
temperature information may be correlated to one or more
characteristics such as color. In a particular embodiment, the
correlation algorithm is adjusted by a clinician. For example, the
clinician may set a particular shade of red to a particular
temperature level. Alternatively or additionally, sound may be used
to represent temperature information, such as sound that changes in
pitch or volume as temperature changes, and the correlation between
temperature level and a sound parameter may be adjustable by a
clinician.
[0105] In addition to temperature map 156, system 10 may provide
numerous forms of information provided by the sensor assembly of
device 100 or one or more other sensors or functional elements of
device 100. Such information may be information that is processed
by one or more algorithms of system 10, such as by electronic
module 150 of FIG. 1. Typical temperature information includes but
is not limited to: average temperature; cumulative temperature;
maximum and minimum temperatures; range of temperatures over time;
and rate of change of temperature. Other information provided
includes but is not limited to: time of day; date; patient ID;
clinician ID; location of procedure; multiple patient location
anatomical description; EKG information; energy delivered
information; and other patient physiologic information. Information
provided can be in alphanumeric and/or graphical forms.
[0106] Also depicted in FIG. 2A is visualization instrument 210.
Visualization instrument 210, typically a real time x-ray unit or
fluoroscope, provides internal images of the patient's anatomy.
[0107] Referring now to FIG. 2B, a cross-sectional image of patient
P of FIG. 2A is shown. Device 100 has been inserted into the
esophagus such that sensor assembly 120 is positioned proximate the
patient's Heart. During an ablation procedure, sensor assembly 120
and device 100 are used to provide temperature map information
configured to prevent damage to the Esophagus while the patient's
Heart is heated and/or cooled. Of particular interest to the
clinician is delivery of energy to the posterior wall of the
patient's Heart, due to the proximity and potential contact between
the Heart and the Esophagus.
[0108] Referring now to FIG. 2C, a cross sectional image of the
patient P's Esophagus of FIGS. 2A and 2B is illustrated. Device 100
has been advanced to the location shown in FIG. 2B, and rotated to
the position shown in FIG. 2C. Sensor assembly 120 includes lens
122, typically 0.5'' to 4'' in length, which is positioned at
tissue locations of the Esophagus that are most proximate the
patient's heart. Sensor assembly 120 is configured to measure
temperature at locations relatively orthogonal to shaft 110 and
without contacting the wall of the Esophagus. Shaft 110 includes
marker 114a and marker 114b, proximal and distal, respectively, to
sensor assembly 120. Markers 114a and 114b are typically radiopaque
markers that are visible to visualization instrument 210 of FIG.
2a. Alternatively or additionally, markers 114a and 114b may be
markers selected from the group consisting of: ultrasonically
reflective markers; electromagnetic markers; visible markers; and
combinations of these.
[0109] Shaft 110 further includes port 116, configured to deliver
one or more fluids from shaft 110. Fluids may be delivered from
port 116 to cool or warm tissue being monitored by sensor assembly
120, such as fluids delivered manually or automatically by system
10 when one or more patient locations exceed one or more
temperature thresholds. Alternatively or additionally, fluids such
as saline may be delivered from port 116 to remove debris covering
lens 122.
[0110] Referring now to FIGS. 3A and 3B, a temperature measurement
probe of the present inventive concepts is illustrated in which the
probe delivers energy and produces a temperature map of multiple
patient locations in front of its distal end. A distal portion of
shaft 110 includes sensor assembly 120 comprising lens 122 and an
array of sensors 121. Sensors 121 are typically an infrared CCD
array or other array configured to record infrared light
information corresponding to a temperature range, such as a
temperature range between 30.degree. C. and 70.degree. C. Sensors
121 are connected to wire bundle 128 which travel proximally and
carry information and/or power to or from sensors 121 as has been
described in detail hereabove.
[0111] The distal end of shaft 110 further includes an electrode,
functional element 160, which is typically configured to deliver
energy such as RF energy. Alternatively or additionally, functional
element 160 may deliver energy selected from the group consisting
of: laser energy; cryogenic energy such as energy delivered by
flowing cryogenic fluid such as liquid nitrogen proximate the
tissue to be ablated; microwave energy; mechanical energy; chemical
energy; electromagnetic energy; and combinations of these.
[0112] Lens 122 and sensors 121 are constructed and arranged to
provide a temperature map for the tissue proximate functional
element 160 prior to, during, and after delivery of energy by
functional element 160.
[0113] Referring now to FIG. 4A, a sectional side view of a
side-viewing temperature measurement probe of the present inventive
concepts is illustrated in which a sensor is advanced and/or
retracted to create a temperature map of multiple patient
locations. Device 100 includes at its distal end, lens 122.
Positioned within lens 122, is sensor 121, typically a sensor
configured to measure and/or transmit infrared light received
through lens 122. Sensor 121 may be configured to measure and/or
transmit infrared light for a single patient location (i.e. a
point) or multiple locations. In an alternative embodiment, sensor
121 and/or another component of device 100 may be configured to
record visible light information or other information such as
ultrasound information.
[0114] In one embodiment, sensor 121 includes multiple sensors
configured to measure temperature at multiple patient locations
such as locations extending radially out from sensor 121 and
covering a circumference of 10.degree. or more, typically
90.degree. or greater, and more typically greater than 180.degree.
In a particular embodiment, sensor 121 records temperature
information at patient locations located at a full circumference
(i.e.) 360.degree. at a range of locations at sensor 121 that are
perpendicular to shaft 110. Alternatively or additionally, drive
assembly 170 may rotate shaft 123 and sensor 121, such as a full
360.degree. rotation or a partial rotation less than 360.degree.,
typically 180.degree. or less or 90.degree. or less, as is
described in reference to FIG. 5 herebelow. Alternatively or
additionally, lens 122 may be constructed and arranged to move
and/or reshape, such as with one or more MEMS mechanisms.
[0115] Sensor 121 is attached to drive shaft 123 and is shown in a
retracted position. Device 100 includes linear drive assembly 170
which includes drive gear 171 and lead screw 172. Drive assembly
170 is configured to advance and/or retract shaft 123 and sensor
121 at one or more velocities.
[0116] Referring now to FIG. 4B, shaft 123 and sensor 121 have been
advanced to the distal portion of lens 122. During advancement and
retraction of sensor 121, temperature information is recorded at
multiple tissue locations proximate to and along the length of lens
122. Temperature map information created by the system of FIGS. 4A
and 4B can be provided in numerous forms, preferably a
two-dimensional display of three dimensional tissue surrounding
lens 122. While the temperature information is recorded
sequentially, a full temperature map may be displayed
simultaneously in which particular patient location temperature
information is updated as it is recorded and processed, techniques
well known to those of skill in the art in creating visible images
and ultrasound images from translating and/or spinning cameras, CCD
arrays, ultrasound crystals and other sensors.
[0117] Referring now to FIG. 5, a sectional side view of a
side-viewing temperature probe of the present inventive concepts is
illustrated comprising a spinning sensor assembly. Device 100
comprises lens 122 positioned on the end of shaft 110. Lens 122 is
configured to focus infrared light received from tissue surrounding
lens 122 onto sensor assembly 120. Surrounding lens 122 are
circumferential markers 114a and 114b, proximal and distal to lens
122, typically radiopaque markers used to identify the position of
sensor assembly 120 under fluoroscopy. Sensor assembly 120 is
typically a linear array of similar or dissimilar infrared light
sensors 121. In an alternative embodiment, lens 122 comprises an
inner and outer lens.
[0118] Sensor assembly 120 is mechanically attached to and rotated
by drive shaft 123 which is centrally positioned within the lumen
of shaft 110 by guide bushing 129. Drive shaft 123 is rotated by
rotational drive assembly 175. Shaft 123 is typically rotated a
full 360.degree., however partial rotations of 180.degree. or less,
or 90.degree. or less may be performed. While being spun, sensor
assembly 120 records a temperature map of the tissue surrounding
sensor assembly 120, such as the wall tissue of a lumen of a
patient, such as esophageal wall tissue.
[0119] Referring now to FIG. 6, a sectional side view of a
side-viewing temperature probe of the present inventive concepts is
illustrated comprising a solid cylinder surrounding an array of
optical fibers that have been assembled in a coherent fiber optic
bundle. Device 100 includes shaft 110, a solid cylinder shaft that
may be flexible or rigid. Shaft 110 surrounds fiber optic bundle
130 comprising a coherent bundle of optical fibers 125, such as
optical fibers which have little or no impedance to infrared
radiation. Bundles may be arranged with as few as one, to as many
as tens of thousands of individual fibers. Fibers may be coated or
uncoated, clad or unclad, and can range in diameter from 50 to 700
microns. The shape of the bundles can be circular of rectangular.
In a particular configuration, a rectangular 60.times.60 fiber
bundle includes 3600 individual fibers, each producing temperature
information for a discrete tissue location. In an alternative
embodiment, a single fiber 125 is contained within shaft 110. In
one embodiment, the fiber or fibers are comprised of germanium
and/or silver halide, however numerous types of fibers may be used
such as fibers constructed of materials selected from the group
consisting of: germanium; arsenic; selenium; sulfur; tellurium;
silver halide; and combinations of these. Amorphous Materials Inc.
of Garland, Tex. is a manufacturer of applicable optical fibers
such as their products AMTIR-1, AMTIR-2, AMTIR-3, AMTIR-4, AMTIR-5,
AMTIR-6, and C1.
[0120] The distal end of fiber optic bundle 130 is arranged at an
angle such that infrared or other radiation passing through lens
122 is received by the beveled end of each fiber 125. The bevel
angle may be chosen to maximize absorption of the received
radiation. In a particular embodiment, a 45.degree. bevel angle is
used. Fiber bundle 130 may be rotated, such as a full 360.degree.
rotation, by one or more rotating drive assemblies (e.g. drive
assemblies used in medical imaging products device industry to
rotate fibers or fiber bundles), not shown. Alternatively, partial
rotations of 180.degree. or less, or 90.degree. or less may be
performed such as to create a less than full circumferential view
of a lumen such as the esophagus of a patient.
[0121] In communication with fiber bundle 130 is a sensor assembly,
not shown but typically proximal to shaft 110 or included in a
proximal portion of shaft 110. The sensor assembly, typically an
infrared sensor assembly comprising an array of infrared sensors,
receives the radiation signals passed through lens 122 into fiber
optic bundle 130. Lens 122 is shown as a circumferential ring that
directs, focuses or otherwise lets radiation pass through lens 122
onto the beveled end of fiber optic bundle 130.
[0122] Referring now to FIG. 7, a sectional view of a side-viewing
temperature probe of the present inventive concepts is illustrated
comprising an enlarged distal portion including a sensor assembly
and a partial circumferential lens. Device 100 includes shaft 110
which surrounds sensor assembly 120 and drive shaft 124. A partial
circumferential lens 122 is positioned relative to sensor assembly
120. In an alternative embodiment, lens 122 is a full
circumferential (e.g. 360.degree.) lens, such as when sensor
assembly 120 is a full 360.degree. viewing sensor. Lens 122 is
constructed and arranged to direct, focus or otherwise allow
radiation to pass onto sensor assembly 120. Lens 122 may be
selected from the same group of materials as infrared transparent
fibers discussed hereabove.
[0123] Sensor assembly 120 includes an array of infrared sensors,
typically an infrared CCD array or other array configured to record
infrared light information. Infrared arrays may be configured to
produce temperature maps based on an array of pixels, such as an
array with a minimum of 10 pixels by 10 pixels. Arrays of 100 by
100 or more pixels may be used, such as to represent an area of
esophageal tissue with a length of one inch or more at an area
proximate a patient's heart. Sensor assembly 120 may include
integrated circuitry, such as to perform one or more of the
following functions: process signals received by sensor assembly
120; multiplex signals; filter signals; combine signals; amplify
signals; and convert electrical signals to optical signals for
fiber optic transmission.
[0124] Sensor assembly 120 mechanically connects to shaft 124 such
as to position sensor assembly relative to lens 122. Lens 122 may
be used to magnify or demagnify a viewed location, and may be used
to expand the field of view. Lens 122 may be configured to be
focused, manually or automatically, in a similar configuration used
in visible light cameras. Additionally, shaft 124 may be configured
to act as an information transmission conduit to the proximal
portion of device 100. For example, shaft 124 may be used to send
and/or receive information and/or power to or from sensor assembly
120. Typically, shaft 124 includes a bundle of wires that
communicate with sensor assembly 120. However, in an alternative
embodiment, shaft 124 may include optical fibers and sensor
assembly 120 includes electronics configured to convert sensor
information into optical data.
[0125] In yet another embodiment, shaft 124 may rotate a full
360.degree. rotation, by one or more rotating drive assemblies, not
shown. Alternatively, partial rotations of 180.degree. or less, or
90.degree. or less may be performed. Here, lens 122 would typically
be 360.degree. or a sufficient circumferential sector to
accommodate the motion of sensor assembly 120.
[0126] Referring now to FIG. 8, a sectional view of a side-viewing
temperature probe of the present inventive concepts is illustrated
comprising a distal portion configured to attach to a proximal
portion. Device 100 includes shaft 110 is electromechanically
attachable to sensor assembly 120 via connector 111, such that
sensor 120 and all components proximal to sensor 120 may be reused.
Shaft 110 and fibers 125 may be disposable, e.g. single use by one
patient only or limited use, or reusable.
[0127] Sensor 120 is optically aligned with a proximal end of
fibers 125 while lens 122 is arranged along the beveled distal end
of fibers 125. This arrangement enables lens 122 to view to the
side or forward depending upon the particular construction and
positioning.
[0128] Referring now to FIGS. 9a and 9b, a side sectional and end
sectional view of a forward looking RF temperature probe of the
present inventive concepts is illustrated. Device 100 includes
sensor 120 positioned proximal to fibers 125 and ablation element
160 at the distal end of device 100. Typically, ablation element
160 is comprised of a platinum-iridium electrode. Ablation element
160 may attach (e.g. via wires, not shown but traveling to a
proximal end of device 100) to an energy generator such as an RF
energy generator. Ablation element 160 is constructed and arranged
to be positioned proximate tissue to be treated, such treatment
including but not limited to: ablation; denaturing; excision;
removal; shrinkage; and the like.
[0129] Lens 122 in combination with fibers 125 cooperate to view
surrounding tissue (e.g. tissue to be ablated and tissue proximate
tissue to be ablated such as tissue intended not to be damaged) so
that the clinician may be alerted if target tissue has reached a
desired temperature and/or the non-target tissue is not exceeding a
desired temperature. For example, when ablating a tumor, if the
tumor has not been entirely ablated, cancer may reoccur or spread
post-procedure. This may occur when a tumor is near a blood vessel,
which acts as a heat sink preventing the tumor from reaching a
desired temperature.
[0130] Referring now to FIG. 10, a sectional view of a side-viewing
temperature probe of the present inventive concepts is illustrated
comprising a thermos construction. The thermos construction of
device 100 is achieved by creating a vacuum between shaft 110 and
hollow tube 117, where hollow tube 117 is typically comprised of
mirrored glass. This particular embodiment may be used to maintain
hollow tube 117 in a thermally stable environment. For example,
noise, such as errors and inaccuracies, may be minimized when
infrared transmissions pass through lens 122 and are reflected to
sensor assembly 120 via mirror 126. In addition, the thermos
construction prevents the temperature of hollow tube 117 from
impacting the image produced by system 10.
[0131] Mirror 126 may be configured to move in a longitudinal path
or rotate by means of a movement assembly, not shown. Additionally
or alternatively, device 100 may have multiple mirrors.
[0132] A partial circumferential lens 122 is positioned relative to
sensor assembly 120. In an alternative embodiment, lens 122 is a
full circumferential (e.g. 360.degree.) lens, such as when sensor
assembly 120 is a full 360.degree. viewing sensor.
[0133] Additionally, this illustration includes an
electromechanically attachable design via connector 111 as
described in FIG. 8 hereabove. However, the device may also
comprise a fixed configuration.
[0134] Referring now to FIG. 11, a side-viewing temperature probe
in accordance with the present inventive concepts is illustrated
comprising an expandable distal portion wherein an integrated
sensor array measures a patient's tissue temperature by directly
contacting the tissue. Device 100 comprising a distal end of shaft
110 includes a membrane, balloon 185, which is shown in an expanded
position. Balloon 185 may be hollow or may have lumens that can
allow air to pass through the center of balloon 185 when
expanded.
[0135] Balloon 185 includes multiple sensors 121 on its surface. In
a preferred embodiment, sensors 121 are thermocouples occupying the
entire surface of balloon 185. Alternatively, sensors 121 may
occupy a portion of balloon 185. Typically, balloon 185 includes
approximately ten sensors 121, and more typically, 100 sensors 121.
In a preferred embodiment, sensors 121 are spaced substantially
equidistant from one another with a separation distance of less
than 0.2 mm. Alternatively, sensors 121 may be spaced less than 1.0
mm from adjacent sensor 121.
[0136] Malleable member 119 may be located on the outer surface of
shaft 100 and/or embedded within the inner and outer wall of shaft
110. Malleable member 119 allows plastic deformation of the distal
portion of device 100. For instance, the clinician may bend device
100 to accommodate the anatomy of the patient, e.g. patient's
esophagus.
[0137] Referring now to FIG. 12, a schematic view of a system in
accordance with the present inventive concepts where a luminal
temperature measurement device is attached to an energy delivery
unit demonstrating potential integration into a tissue ablation
system. System 10 includes device 100 and ablation system 250.
[0138] Ablation system 250 includes ablation catheter 253 which
comprises ablation elements such as electrodes, cryogenic balloons,
ultrasound crystals, and the like. System 250 further includes
monitor 255 which may show ablation catheter information, EKG
information, energy delivery information, and other information. In
addition, display 155 shows temperature map 156 information,
described in FIG. 1 hereabove. Alternatively, display 155 may be
integrated into monitor 155.
[0139] Ablation system 250 further comprises energy delivery unit
251 which may deliver various types of energy including:
radiofrequency (RF) energy; laser energy; cryogenic energy;
subsonic energy; acoustic energy; ultrasound energy; microwave
energy; chemical energy; and combinations of these. Energy delivery
unit 251 includes user interface 252 which may comprise one or more
controls used in cooperation with device 100 and ablation catheter
253. Additionally, a signal analyzer may be integrated into unit
251 and device 100 and/or another device. User interface 252
includes adjustable controls, e.g. emergency shut-off of unit 251
and/or an alarm system, and data generated by a signal analyzer are
as described in FIG. 1 hereabove.
[0140] Alternatively or additionally, all components of system 10
may include a memory storage device for recording of historic data,
such as historic values of multiple patient locations, also
described in FIG. 1 hereabove.
[0141] Referring now to FIG. 13, a sectional view of a side-viewing
temperature probe in accordance with the present inventive concepts
is shown within a body lumen of a patient, such as the esophagus,
wherein the device includes an integral tissue tensioning assembly.
Device 100 comprises outer sheath 115, which slidingly encloses
shaft 110. Additionally, expandable cage 185 is typically
positioned on a proximal portion of device 100 and configured to
radially contact a patient's esophageal wall. Expandable cage 185
may be expanded upon the command of a clinician via a control
mechanism, not shown.
[0142] Expandable cage 185' may be attached to outer sheath 115
such that applying force in the proximal direction tensions luminal
wall tissue to create a uniform tissue surface reduce, e.g. to
eliminate one or more crevices hidden within the portion of tissue
and therefore outside the view of lens 122 and sensor assembly 120.
Additionally or alternatively, cages 185 and/or 185' may radially
tension a patient's tissue. Additionally or alternatively, cages
185 and/or 185' specifically position lens 122 and sensor assembly
120 within a lumen of a patient, e.g. the center of a lumen.
[0143] Expandable cage 185 and/or 185' may be arranged in numerous
forms while remaining configured to contact a patient's tissue such
that force applied between shaft 110 and outer sheath 115 tensions
the tissue between cages 185 and/or 185'. For example, cages 185
and/or 185' may include a balloon, which may expand by filling with
a gas such as air or a liquid, such as saline. Also, cages 185
and/or 185' may be a stent or opposing fingers, spokes or other
projections. Additionally or alternatively, cages 185 and/or 185'
may include a shape memory device.
[0144] In this embodiment, a partial circumferential lens 122 is
positioned relative to sensor assembly 120. In an alternative
embodiment, lens 122 is a full circumferential (e.g. 360.degree.)
lens, such as when sensor assembly 120 is a full 360.degree.
viewing sensor.
[0145] Device 100 includes lumen 118, which may be used to carry
fluid from a proximal portion of device 100 to ports on the
proximal end of device 100, such as ports 105a and/or 105b of FIG.
1. Examples of fluids include: cooling fluid, such as saline, a
therapeutic drug or other agent, or combinations of these.
[0146] In an alternative embodiment, a sensor may be placed within
expandable cage 185 and/or 185' to measure temperature, pressure,
pH, and/or other physiologic parameters of a patient.
[0147] In yet another embodiment, outer sheath 115 and expandable
cage 185' may be a separate device working in cooperation with the
remaining components of device 100.
[0148] Referring now to FIG. 14, a sectional view of a side-viewing
temperature probe in accordance with the present inventive concepts
is shown within a body lumen of a patient, such as the esophagus,
wherein the device has integral positioning members and fluid
injection ports. Device 100 includes positioning members 185a and
185b located proximal and/or distal to lens 122. Members 185a and
185b position the distal portion of device 100 and are configured
to be positioned asymmetrically within a lumen of a patient. Types
of positioning members 185a and 185b are similar to those described
in FIG. 13 hereabove.
[0149] Device 100 may also include a tissue temperature modifying
assembly, which is configured to cool or warm multiple patient
locations. An endothermic reaction will occur to cool the tissue,
while an exothermic reaction will occur to warm the tissue.
[0150] Additionally or alternatively, a fluid may exit ports 116a
and/or 116b to cool or warm the tissue, e.g. via heated saline.
Also, a Peltier component may be included to cool or warm fluid
prior to exiting ports 116a and/or 116b.
[0151] In an alternative embodiment, a separate catheter device
including fluid injection ports 116a and 116b may be included on
the distal portion of device 100.
[0152] Referring now to FIG. 15A, a side view of a side-viewing
temperature probe in accordance with the present inventive concepts
is illustrated including an outer sheath that may be advanced
and/or retracted to clean the lens of the device. Device 100
includes cleaning assembly 180, a slideable sheath which fixedly
surrounds shaft 110, and includes edge 181 positioned at its distal
end.
[0153] Cleaning assembly 180, in cooperation with edge 181, may be
used to clean debris, such as mucus, blood, or other biological
material or non-biological contaminants from lens 122, such as when
device 100 is placed into a body location such as the esophagus or
other body lumen. Components of a sensor assembly, such as mirrors,
lenses such as lens 122, and/or one or more arrays of infrared
sensors, not shown but described in detail in reference to other
figures included herein, may be adversely impacted by debris on
lens 122 and may require at least one cleaning during use.
[0154] Cleaning assembly 180 and edge 181 perform a wiping function
such as by advancing cleaning assembly 180, as shown in FIG. 15B,
causing edge 180 to wipe debris from lens 122. A repeated back and
forth motion may be used to clean lens 122, and one or more
cleaning fluids such as saline may be delivered from a port, not
shown but typically proximate edge 181 as is described in reference
to FIG. 16 herebelow.
[0155] In an alternative embodiment, device 100 may include
multiple cleaning assemblies 180, wherein each cleaning assembly is
disposable. For example, first cleaning assembly may be utilized
for a single patient and the second utilized for the same patient
or a different patient.
[0156] In yet another embodiment, cleaning assembly 180 may be
removable from device 100. Additionally or alternatively, cleaning
assembly 180 may have a longitudinal slit 183 enabling lateral
attachment to shaft 110 while shaft 110 is placed into a lumen of a
patient, and one or more cleaning assemblies 180 may be laterally
attached to shaft 110 one or more times during a single
procedure.
[0157] Referring now to FIG. 16, a side sectional view of a
side-viewing temperature probe in accordance with the present
inventive concepts is shown within a body lumen of a patient, such
as the esophagus, wherein the device includes a cleaning assembly
designed to remove debris from a lens or other portion of the
probe. Device 100 includes shaft 110 and sensor assembly 120
positioned in a distal portion of device 100 and configured to
provide temperature information for multiple patient locations.
Lumen 118 connects to a port, not shown but typically a standard
luer connector, positioned on the proximal end of device 100 so
that an infusion delivery device, such as a syringe or pump,
dispenses cleaning medium 182 through lumen 118 and out of port
116. Port 116 may include a nozzle or other flow director such as
to direct cleaning medium 182 onto lens 122 and/or another optical
or other component of device 100. Cleaning medium 182 may be a
liquid or gas, and is typically saline. Additionally or
alternatively, cleaning medium may be saline or other biologically
compatible material, and may include a cleaning agent such as a
detergent. Further, cleaning medium 182 may be warmed or
cooled.
[0158] Device 100 may include a second cleaning assembly. For
example, a second port may be connected to lumen 118 or a different
lumen, such as to clean debris from another portion of lens 122 or
another portion of device 100.
[0159] Referring now to FIG. 17, a partial sectional side view of a
side looking temperature probe in accordance with the present
inventive concepts is illustrated, including an integral
temperature stabilizing assembly constructed and arranged to
improve the quality of the temperature map of multiple patient
locations by reducing or eliminating the effect of varied or
varying temperatures of one or more components of the temperature
probe. Mirror 126 cooperates with lens 122 to transmit radiation
(e.g. infrared radiation) through shaft 110 in a proximal direction
to one or more sensor assemblies, not shown but typically located
in a handle or other proximal portion of device 100, or an
electronic unit connected to device 100. Mirror 126 and lens 122
may be further configured as described in FIG. 10 hereabove such
that device 100 produces a temperature map of multiple patient
locations.
[0160] Device 100 of FIG. 17 includes a thermos construction and a
circulating fluid pathway that independently or in combination help
to maintain shaft 110, mirror 126, lens 122 and/or another
component or portion of a component of device 100 at a constant
temperature, such as to reduce infrared radiation artifacts that
reduce the quality of the temperature map produced by device
100.
[0161] Shaft 110 is positioned within outer sheath 115 in a
thermos-like construction to maintain one or more components of and
spaces within device 100 in a relatively isothermal condition. The
outer surface of shaft 110 and/or the inner surface of outer sheath
115 may have a mirrored or other reflective surface. Shaft 110 may
comprise a glass material with a mirrored surface, common to
thermos devices and used to avoid heat transfer to or from shaft
110.
[0162] Alternatively or additionally, device 100 may be configured
to allow a fluid to pass through space 131A and space 131B between
shaft 110 and outer sheath 115 and exit thru-hole 132 at the distal
end of device 100, such as to maintain shaft 110, lens 122 and/or
mirror 126 in a stable, constant temperature state. Fluid may be
delivered around shaft 110 such as to warm or cool shaft 110 or
another component of device 100. Heating and/or cooling assemblies
(e.g. Peltier components) may be used to increase, decrease and/or
stabilize temperature of the fluid or a component of device 100. In
one embodiment, temperature is maintained above or below body
temperature.
[0163] Device 100 includes temperature sensors 163, typically
ring-shaped, configured to monitor temperature of outer sheath 115,
shaft 110 and/or a fluid traveling through outer sheath 115 and
shaft 110. Additionally, sensors 163 may monitor the temperature of
the environment in which device 100 is placed, e.g. patient tissue
surrounding device 100. Sensors 163 may be used to provide
temperature information fed back to the fluid delivery device or a
heat exchanging device such that closed loop temperature control
can be achieved. Alternatively or additionally, one or more sensors
163 may sense a parameter other than temperature, such as a sensor
configured to measure a pressure, an electromagnetic condition, a
physiologic parameter, or other condition.
[0164] A potential advantage of integrating a temperature
stabilizing assembly within device 100 is that the performance of
device 100 is improved by reducing the adverse effects of varied
and varying temperatures of any component or a portion of any
component of device 100, such as temperature variations within
shaft 110, lens 122, mirror 126 and/or another component or portion
of shaft 110.
[0165] Referring now to FIG. 18, a flow chart of a method for
analyzing and/or processing temperature information to produce a
temperature map of multiple patient locations is illustrated. In a
first step, information received from a sensor assembly and/or
another component or assembly of a system in accordance with the
present inventive concepts is analyzed and/or processed such as via
one or more image processing or other algorithms. As a result of
this analysis and/or processing, a temperature map of multiple
patient locations is displayed. The system comprises many features
enabling the user, e.g. a clinician, to analyze temperature and
other data. Numerous image stabilization algorithms may be
employed, such as an image stabilization algorithm based on an
accelerometer included in a temperature probe in accordance with
the present inventive concepts.
[0166] The system may include manual or automatic panning and
zooming functions. For example, an auto-zoom feature enables the
clinician to zoom into an area where tissue temperature has
increased. In one embodiment, if a temperature of an area outside
the periphery of the display or along the boundary of the display
increases, the display may automatically reposition and/or zoom out
with or without operate input. In another embodiment, if a tissue
area monitored by the device includes a temperature change that is
not currently being viewed, the displayed information may
automatically change such as via zooming out or repositioning at
the same zoom.
[0167] An additional analytical feature of the system includes an
alert detection component where the clinician may be alerted if
tissue rises or falls outside a desired or expected temperature
and/or outside a range of desired or expected temperatures. For
example, if the desired tissue temperature is 37.degree. C., and
one or more tissue locations reach 50.degree. C., the clinician may
be alerted. Alternatively or additionally, one or more alerts may
be included based on mathematical or other processing of
temperature information, such as an algorithm which integrates
temperature over time for one or more tissue locations.
[0168] The data analysis of the device may comprise an error
checking algorithm that is configured to detect inconsistencies,
such as one or more readings that are outside of one or more
pre-determined boundary conditions. For example, if 10,000 data
points are reading 37.degree. C., and one data point is reading
50.degree. C., the system will detect and alert the clinician that
50.degree. C. is inaccurate.
[0169] As described in reference to FIG. 1, system 10 may include
an alert device such as an audible transducer. An audible
transducer can be configured to produce sounds that correlate to an
analysis of temperatures. For example, a continuous beep may sound
if the tissue temperature exceeds a desired temperature. In another
example, one or more sounds represent temperature related
information (e.g. processed temperature information) including but
not limited to: cumulative temperature from multiple locations;
average temperature; maximum temperature; temperature above a
threshold; and combinations of these. The produced sound may
represent one or more temperature or calculated temperature values
based on one or more of: frequency; sound pattern; and volume.
[0170] Alternatively or additionally, a visible transducer may be
included within the system, such as an LED. Here, a light may blink
if the tissue temperature exceeds a desired temperature, or a
pattern of blinking and/or light intensity may represent
temperature related information.
[0171] The system may further comprise a noise reduction algorithm
wherein the system may filter out known sources of noise, e.g.
known infrared radiation sources.
[0172] The system may also comprise a calibration assembly, which
may include a subroutine integral to a start-up or other system
condition (e.g. for each new patient use). Additionally or
alternatively, a calibration assembly may use a calibration
standard proximate the device or within the device.
[0173] In addition to a temperature map, additional information may
be processed and/or analyzed. For example, information received
from a visible light sensor (e.g. a CCD camera), an ultrasound
imaging device, and the like, may be analyzed and processed by the
system.
[0174] In addition to displaying a temperature map, a control
signal may be produced based on the analysis and/or processing of
temperature information received from the sensor assembly in
accordance with the present inventive concepts. In one embodiment,
a feedback circuit may be included to control an energy delivery
unit, e.g. an energy delivery unit used to prove ablation energy to
a device positioned to ablate the heart of a patient. For example,
a particular result from the data analysis may cease or modify,
e.g. increase or decrease, the amount of energy delivered from an
energy delivery unit. In one embodiment, the energy delivery device
is unable to deliver energy to the system if it is not attached to
the device or system. Additionally or alternatively, a feedback
circuit may control a cooling and/or warming assembly, such as a
cooling or warming assembly configured to cool or warm tissue when
a measured temperature rises above or below, respectively, a
threshold.
[0175] Referring now to FIG. 19, a side view of a side-viewing
temperature probe in accordance with the present inventive concepts
is illustrated comprising reusable and disposable portions as well
as a sensor mounted to a rotatable drive shaft. Device 100 includes
sensor 121 which is constructed and arranged to provide temperature
information such that a temperature map of multiple patient
locations can be displayed. Sensor 121 is fixedly mounted to a
distal end of drive shaft 123 which travels proximally through
shaft 110. Drive shaft 123 may be an optical fiber, such as when
sensor 121 is a modified end to a fiber and/or a lens or mirror
attached to the end of a fiber. Drive shaft 123 may include one or
more wires such as when sensor 121 is an electronic assembly which
transmits information down a wire of drive shaft 123. Lens 122 is
positioned at a longitudinal location on outer sheath 115 that is
proximate sensor 121.
[0176] In one embodiment, drive shaft 123 rotates sensor 121
enabling sensor 121 to view through a partial circumferential lens
122, e.g. a lens covering 90.degree. or 180.degree. of the
circumference of sheath 115. The rotation of sensor 121 may be
continuous in a circular path, i.e. spin past the partial
circumference of the lens 122, leaving a void in the viewing
window. Alternatively, the rotation of sensor 121 may be
reciprocating, i.e. in a back and forth motion to maintain view
within the partial circumference of lens 122, such as to translate
over a distance of at least 1 mm, typically between 10 mm and 80
mm, more typically at least 20 mm. Alternatively, lens 122 is
wider, e.g. 360.degree., and sensor 121 would have continuous
viewing capabilities as sensor 121 is rotated continuously by shaft
121.
[0177] In a typical embodiment, linear drive assembly 170 is
operably connected to shaft 123, which rotates and moves axially in
a forward and back motion; this technology is currently used in
intravascular ultrasound 3-D imaging products. In this particular
embodiment, sensor 121 is capable of viewing through substantially
all of the surface area of lens 122.
[0178] In a particular embodiment, device 100 includes positioning
members 185, as discussed in FIG. 13 hereabove, and outer sheath
115, which are typically supplied sterile, while linear drive
assembly 170 and shaft 110 may be non-sterile. Alternatively or
additionally, positioning members 185 and outer sheath 115 may be
disposable, e.g. single use by one patient only or limited use,
while linear drive assembly 170 and shaft 110 may be utilized for
multiple patient procedures.
[0179] While the preferred embodiments of the devices and methods
have been described in reference to the environment in which they
were developed, they are merely illustrative of the principles of
the inventive concepts. Modification or combinations of the
above-described assemblies, other embodiments, configurations, and
methods for carrying out the inventive concepts, and variations of
aspects of the inventive concepts that are obvious to those of
skill in the art are intended to be within the scope of the claims.
In addition, where this application has listed the steps of a
method or procedure in a specific order, it may be possible, or
even expedient in certain circumstances, to change the order in
which some steps are performed, and it is intended that the
particular steps of the method or procedure claim set forth
herebelow not be construed as being order-specific unless such
order specificity is expressly stated in the claim.
* * * * *