U.S. patent application number 14/161297 was filed with the patent office on 2014-05-15 for method and apparatus for peritoneal hypothermia and/or resuscitation.
The applicant listed for this patent is Jared C. Blanton, Daniel R. Burnett, Shane Mangrum. Invention is credited to Jared C. Blanton, Daniel R. Burnett, Shane Mangrum.
Application Number | 20140135878 14/161297 |
Document ID | / |
Family ID | 37963393 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140135878 |
Kind Code |
A1 |
Burnett; Daniel R. ; et
al. |
May 15, 2014 |
Method and Apparatus for Peritoneal Hypothermia and/or
Resuscitation
Abstract
Embodiments of the invention provide apparatus, systems and
methods for introducing fluids into a body cavity for hypothermic,
resuscitative, or other treatment. One embodiment provides an
apparatus for introducing fluids into a peritoneal cavity
comprising an access device for insertion into subcutaneous tissue,
an infusion member and an advancement member. The access device
includes a lumen, a proximal end, a tissue penetrating distal end
and a stop for controlling the depth of the distal end into tissue.
The infusion member includes an infusion lumen, a removal lumen and
at least one sensor and is advanceable from a lumen of the access
device into the peritoneal cavity. The advancement member is
removably positionable in an infusion member lumen and has
sufficient column strength to advance the infusion member tip
through abdominal wall tissue into the peritoneal cavity. When the
advancement member is removed, the infusion member tip is
substantially atraumatic.
Inventors: |
Burnett; Daniel R.; (San
Francisco, CA) ; Mangrum; Shane; (Idaho Falls,
ID) ; Blanton; Jared C.; (Oakland, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Burnett; Daniel R.
Mangrum; Shane
Blanton; Jared C. |
San Francisco
Idaho Falls
Oakland |
CA
ID
CA |
US
US
US |
|
|
Family ID: |
37963393 |
Appl. No.: |
14/161297 |
Filed: |
January 22, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11552090 |
Oct 23, 2006 |
8672884 |
|
|
14161297 |
|
|
|
|
60728785 |
Oct 21, 2005 |
|
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Current U.S.
Class: |
607/105 |
Current CPC
Class: |
A61F 7/12 20130101; A61F
2007/126 20130101; A61M 25/003 20130101; A61F 2007/0094 20130101;
A61M 2025/0034 20130101; A61M 1/28 20130101; A61M 1/285 20130101;
A61M 25/007 20130101; A61M 1/32 20130101; A61M 1/281 20140204; A61M
2025/0037 20130101; A61M 31/00 20130101 |
Class at
Publication: |
607/105 |
International
Class: |
A61F 7/12 20060101
A61F007/12 |
Claims
1. An apparatus configured to induce hypothermia in a patient, the
apparatus comprising: an access device configured to be inserted a
controlled depth into a peritoneal cavity of the patient, the
device including a lumen and a tissue penetrating distal end; a
sensor configured to determine an entry point into the peritoneal
cavity; an infusion member positioned within a lumen of the access
device and advanceable into the peritoneal cavity of the patient,
the infusion member including a first lumen and a second lumen for
the infusion and removal of a hypothermic fluid into and out of the
peritoneal cavity; a temperature sensor configured to monitor a
temperature of the patient; and an electronic controller configured
to infuse the hypothermic fluid into the peritoneal cavity through
the infusion member based on the monitored temperature to reduce
the temperature of the patient to a selected temperature.
2. The apparatus of claim 1, wherein the first or second lumen is
sized to deliver sufficient fluid to the cavity to reduce patient
body temperature by at least about 3.degree. C. through heat
exchange with peritoneal tissue.
3. The apparatus of claim 1, wherein the first lumen is configured
for infusion of hypothermic fluid into the peritoneal cavity and
the second lumen is configured for removal of hypothermic fluid
from the peritoneal cavity.
4. The apparatus of claim 3, wherein the infusion member includes
at least one aperture positioned on a wall of the infusion
member.
5. The apparatus of claim 4, wherein the at least one aperture
opens to the second lumen.
6. The apparatus of claim 5, wherein the at least one aperture
includes a plurality of apertures distributed along a distal
portion of the infusion member.
7. The apparatus of claim 6, wherein the at least one aperture
opens to the first lumen.
8. The apparatus of claim 7, wherein the at least one aperture is
protected from tissue obstruction during advancement of the
infusion member by a barrier coupled to the infusion member.
9. The apparatus of claim 1, wherein the first lumen extends
through to a distal end of the infusion member and the second lumen
is closed at the distal end of the infusion lumen.
10. The apparatus of claim 1, wherein the infusion member is a
catheter, a dual lumen catheter or a multi-lumen catheter.
11. The apparatus of claim 1, wherein the sensor is positioned at a
distal portion of the infusion member or the access device.
12. The apparatus of claim 1, wherein the sensor is a temperature,
pressure or flow sensor.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 11/552,090 filed Oct. 23, 2006, which application claims the
benefit of priority of U.S. Provisional Application No. 60/728,785
filed Oct. 21, 2005, the full disclosures of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention relate to apparatus and methods
for providing therapeutic hypothermia treatment to a patient. More
specifically embodiments of the invention relate to apparatus and
methods for providing therapeutic hypothermia to a patient as well
as resuscitation using extracorporeal peritoneal circulation.
[0004] Hypothermia has been shown to provide distinct medical
benefits to stroke and cardiac arrest patients by limiting the size
of the infarction and related tissue injury if initiated soon
enough and if the level of cooling is significant enough. Both of
these limitations, initiation of and depth of cooling, have made
practical application of the technology quite challenging
particularly in an ambulance or other emergency settings in the
field. Initiation of cooling, for example, is a major issue since
most technologies require sophisticated machinery that would be
difficult to place in ambulance so the patient, at best, receives
the hypothermic benefit sometime after they reach the hospital. Of
the technologies that can be initiated in the field, though, such
as cooling blankets, cooling caps, etc., the depth of cooling is a
major issue due to surface area limitations, complications (such as
intense shivering response) and patient access issues (once the
blanket is on, it may be difficult to access the patient).
[0005] Thus, there exists a need for improved devices for rapidly
producing hypothermia to treat stroke, severe cardiac events and
related conditions, particularly in field settings.
BRIEF SUMMARY OF THE INVENTION
[0006] Embodiments of the invention provide apparatus, systems and
methods for achieving therapeutic hypothermia using minimally
invasive access of the peritoneal cavity or other body cavity. Such
embodiments can use minimally invasive methods to deliver and
circulate hypothermic solutions to the peritoneal or other body
cavity to reduce body temperature to a selected level for treatment
of a number of medical conditions where there is diminished
perfusion to one or more locations in the body. Such conditions can
include various cardiac conditions including myocardial infarction
and cardiac arrest; cerebral conditions including stroke and head
trauma; and various hemorrhagic events due to arterial dissection
or rupture or trauma. Particular hypothermic regimens (e.g.,
temperature and rate of cooling) can be employed to treat
particular conditions e.g., stroke vs. myocardial infarction so as
to reduce the amount of ischemic reperfusion injury to vital organs
resulting from the particular ischemic event. Also, embodiments can
have hypothermic regimens for various surgical procedures to reduce
the amount of post-surgical inflammation and to provide a tissue
protective effect so as to extend the operating times for various
procedures which require reduced perfusion at the surgical site or
throughout the body. Examples of the latter application can include
open-heart procedures where the heart can be cooled to allow for
longer periods where the heart is arrested and neurosurgical
procedures to provide a neuro-protective effect for tissue at or
near the operative site. Selection of a particular hypothermic
regimen can be made by the user from a database of regimens stored
in memory resources within a system control unit (e.g., a console)
or otherwise electronically coupled to the system either directly
or wirelessly. In particular embodiments, the hypothermic regimen
can be stored in a flash memory or other non-volatile memory device
coupled to a disposable catheter set or kit used by the system. The
memory device could then interface and upload the regimen to the
control device, for example a docking station that the flash memory
device plugs into. RF and other wireless interfaces to the system
control device using BLUE TOOTH or another protocol are also
contemplated.
[0007] These and related embodiments can also be utilized for
patient resuscitation from various ischemic, hemorrhagic events
(e.g., stroke, or cardiac arrest) as well as shock through the use
of peritoneal therapeutic solutions which can be used to oxygenate
ischemic tissue, reduce reperfusion injury, and increase blood
pressure by exerting a compressive force against the peritoneal or
other body cavity vasculature. Such therapeutic solutions can
include various peritoneal dialysis solutions which can comprise
nutrients and one or more reperfusion injury protective agents.
Also, the solution can comprise oxygenated solutions such as
oxygenated fluorocarbon solutions that can be configured to deliver
sufficient oxygen to tissue (by gas exchange with peritoneal or
other surrounding tissue) to at least partially meet the oxygen
demands of the body. For embodiments of the invention used to treat
shock, the solution need not be chilled and can actually be
warmed.
[0008] Also, many embodiments of the invention can be configured as
a portable body cavity infusion/hypothermic system that can be
readily transported in an ambulance, carried and used at a trauma
scene by EMT's, military medics and emergency room personnel. Thus,
one or more components of the system can include a handle, or the
entire system can be integrated into an assembly having a handle.
Further, as described herein, embodiments of a portable system can
be configured for ease of use so as to require minimal set up time
and manual dexterity by medical personnel. For example, embodiments
of the system can use a sub-cutaneous access device that uses a
stop or other means to control the depth of penetration into
subcutaneous tissue so that the user need not have to precisely
position the access device. This access device can be used in
conjunction with an infusion catheter having a sensor configured to
alert the user when the catheter has entered the peritoneal cavity
so as to minimize or eliminate the risk of injuring a peritoneal
organ. The infusion catheter can make use of quick connections for
rapid connection to liquid and gas sources, fluid collection
devices and other system components. The subsequent infusion and
thermal control of fluids can then be automated through use of a
computer controller or other electronic controller. In use, such
embodiments provide a system with a fast set up time, high degree
of reproducibility, and requires minimal dexterity and training of
medical personnel.
[0009] One embodiment of the invention provides an apparatus for
accessing and introducing fluids into the peritoneal or other
cavity of a patient to produce hypothermia. The apparatus comprise
an access device configured to be inserted into subcutaneous
tissue, an infusion member and an advancement member. The access
device includes a lumen, a proximal end, a tissue penetrating
distal end and a stop. The access device can include a surgical
port device. The stop is configured to control the penetration
depth of the distal end of the access device into tissue, such as
the subcutaneous tissue of the abdominal wall or other tissue wall.
The stop can also include an adhesive or suture opening to affix or
otherwise immobilize the access device on the surface of the skin.
The stop can also be adjustable (e.g., by indexing) to allow the
user to select the penetration depth. By controlling the
penetration depth of the access device, the stop serves to make the
insertion procedure more reproducible, less technique dependent,
and reduces the risk of over insertion.
[0010] In various embodiments, the distal end of the access device
can also be transformable from a tissue penetrating configuration
to a non-tissue penetrating safety configuration. This can be
achieved by configuring the distal end to be retractable, to be
shearable (e.g., by the advancement member) or to have an overlying
movable sheath which is withdrawn during advancement and covers the
distal end once the access device is positioned. In use, the
transformable distal end serves to further improve the safety of
the insertion procedure by reducing the risk of inadvertent tissue
injury once the access device is positioned.
[0011] The infusion member can be positioned within a lumen of the
access device and be advanceable into the peritoneal or other body
cavity. The infusion member can include a tissue penetrating distal
end to allow advancement from subcutaneous tissue into the
peritoneal cavity. The tip can be constructed from flexible
materials such that when it is not supported by the advancement
member it is substantially atraumatic. The tip or other portion of
the infusion member can also include one or more sensors configured
to sense one or more of flow through the infusion member, pressure
or temperature. In particular embodiments, the sensor can be a flow
or pressure sensor configured to determine when the tip has entered
the peritoneal or other cavity so as to minimize the chances of
injuring a peritoneal organ during infusion member advancement.
[0012] Typically, the infusion member will include a first lumen
and a second lumen for the infusion and removal of fluid into and
out of the peritoneal or other cavity. Additional lumens are also
contemplated, for example for a guide wire, introduction of
medicaments or as dedicated sensing lumens. The lumen can be can
extend over all or a portion of the length of the infusion member.
The first lumen or infusion lumen allows for the infusion of
hypothermic solutions (also called infusate) into the peritoneal
cavity so as to produce selected amounts of hypothermia from heat
exchange with the hypothermic solution, the peritoneal organs and
tissue. In various embodiments, the infusion lumen can be sized to
allow the delivery of sufficient hypothermic solutions into the
peritoneal cavity to produce a drop in body temperature of
3.degree. C. or more within ten minutes or less. Lumen sizes to
produce temperature reductions of 5 or even 10.degree. C. are also
contemplated. The second lumen or removal lumen can be sized to
allow for the removal of solution at a rate equal to that infused.
The removal lumen is desirably not continuous to the very tip of
the infusion member to allow for the advancement member to have a
surface to push against so as to advance the infusion member.
Alternatively, the removal lumen can neck down near the distal end
of the infusion lumen so as to be able to hold the advancement
member by an interference fit.
[0013] Typically, the infusion member will include one or more
apertures coupled to the first and second lumen. Those coupled to
the first lumen can be positioned at the distal end of the infusion
member for the outflow of the infusate solution. The aperture(s)
can be positioned so as to reduce the likelihood of obstruction by
tissue when the infusion member is advanced, for example by
positioning the aperture on a side of the tip or placing the
aperture behind a barrier coupled to the infusion member. The
apertures coupled to the second lumen can comprise a plurality of
apertures distributed along a length of the distal portion of the
infusion member. The spacing of the apertures can be configured to
maintain patency of at least a portion of the apertures when
inserted in the peritoneal cavity, and still maintain the
flexibility and structural integrity of the infusion member.
[0014] In particular embodiments, the infusion member can comprise
a flexible catheter fabricated from flexible biocompatible polymers
known in the art, such as silicone or polyurethane. In a preferred
embodiment, the infusion member comprises a dual lumen flexible
infusion catheter, with one lumen for infusion of various solutions
and a second for removal. Also, the distal tip or other portion of
the infusion catheter can be tapered to provide additional
flexibility. The proximal end of the catheter can include a luer
lock or other fitting or adapter (e.g., a Y adapter) for quick
connection to one or more fluid, gas, pressure and vacuum sources,
and fluid receptacles. The proximal end or other portions of the
catheter can also include a flash memory device (with an embedded
infusion control/hypothermic regimen software module) that plugs
into a system control device described herein. Also, the infusion
catheter can be configured to be kink resistant for example through
the use of braiding (internal or external) or other supporting
means. Braiding can also be configured to provide for use of higher
infusion pressures, for example during rapid infusion of a bolus of
hypothermic solution.
[0015] The advancement member is removably positionable in at least
one of the two lumens, and desirably has sufficient column strength
to advance the infusion member through the abdominal wall or other
tissue and into the peritoneal cavity by manipulation of a proximal
portion of the infusion member or the advancement member. Ideally,
the advancement member has a length such that the proximal end of
the advancement member extends past the proximal portion of the
infusion member (when fully inserted into the infusion member) so
that the proximal end of the advancement member can be readily
manipulated by the user. Desirably, the advancement member will
have a handle or grip at its proximal portion. The diameter of the
advancement member is sized such that it can be readily advanced or
withdrawn from the infusion member with minimal, or in some cases,
slight resistance. In various embodiments, the advancement member
can be fabricated from various metals such as stainless steel or
rigid polymers known in the art. In addition to having sufficient
column strength to advance the infusion member, the advancement
member can also be configured to have sufficient column strength to
push (i.e., shear) through the inner distal end of embodiments of
the access device that have a shearable distal end.
[0016] Typically, the advancement member will be positioned in the
removal lumen so as to allow for flow of solution through the
infusion lumen during advancement of the infusion catheter. Also,
the infusion member can have a Touhy-Borst type of adjustable valve
positioned around the advancement member to form a fluidic seal
around the advancement member during movement or when stationary.
The valve can also be configured to fluidically seal the proximal
end of the removal lumen when the advancement member is not in
place. The adjustable valve can be configured to not only form a
fluidic seal around the advancement member, but also to hold the
advancement member in place within the infusion catheter. This
allows the user to selectively position the advancement member in
the infusion catheter during advancement of the latter. This
positioning, in turn, can allow the user to select the amount of
flexibility or stiffness of the distal portions of the infusion
catheter.
[0017] An exemplary embodiment of a method for using one or more of
the above embodiments to deliver fluid to a body cavity of a
patient for hypothermic or other treatments can comprise inserting
the access port or other access device a controlled depth into a
tissue wall of the patient. The access port can then be fixed in
place via an adhesive or through use of a suture put through tissue
and a suture eyelet or other opening on the access port. An
infusion catheter or other infusion member can then be through the
access port utilizing through use of a rigid advancement member
positioned in the infusion catheter. The point when the distal tip
of the infusion member enters the body cavity can then be
determined using one or more sensors configured to sense properties
such as force, pressure or fluid flow rate through the infusion
member. In the latter two cases, the infusion member can be
connected to the fluid pressure source during advancement with
entry determined by an increase in flow rate or a decrease in
pressure. Once entry is sensed, a control unit coupled to the
sensor can output an audio alarm or other signal to medical
personnel to alert them of the entry so they can stop advancing the
infusion member to prevent penetration injury of organs within the
cavity. The advancement member is then removed from the infusion
member so as to render the distal tip of the infusion member
substantially atraumatic. Various hypothermic, nutrient and other
solutions can then be infused into the cavity through the infusion
member to achieve a desired hypothermic, resuscitative or other
medical effects or a combination thereof. In various embodiments,
this method can be used to infuse fluid into a peritoneal cavity to
achieve a desired level of hypothermia for treating one or more of
cardiac arrest, myocardial infarction, stroke, head or other
trauma, hemorrhage or post-surgical inflammation. Similar effects
can be achieved by infusing such fluids into the pleural or other
body cavity.
[0018] Another embodiment provides an apparatus for accessing and
introducing fluids into a peritoneal cavity of a patient in order
to achieve selected levels of hypothermia. The apparatus comprises
an access device configured to be inserted through the abdominal
wall and into the peritoneal cavity, an infusion member
positionable within a lumen of the access device and advanceable
into the peritoneal cavity. The access device includes a lumen, a
proximal and a distal end having a tissue penetrating configuration
and a non-tissue penetrating safety configuration. The access
device is transformable to the safety configuration upon
penetration through an abdominal wall. The infusion member includes
at least one lumen for the infusion or removal of fluid into or out
of the peritoneal cavity. The lumen is sized to deliver sufficient
fluid to the cavity to reduce the patient's body temperature by at
least about 3.degree. C. through heat exchange with peritoneal
tissue.
[0019] Another embodiment provides a system for producing
hypothermia in a patient comprising the above apparatus; a fluid
reservoir operatively coupled to infusion member; a pressure source
operatively coupled to the reservoir; a vacuum source operatively
coupled to infusion member; at least one sensor operatively coupled
to at least one of the pressure source, the vacuum source or the
infusion member; a control unit operatively coupled to at least one
of the pressure source, the vacuum source, the infusion member or
the at least one sensor. At least one valve can also be operatively
coupled to the control unit and one of the infusion member or the
pressure source. The valve can be a control valve and can be
configured to control fluid flow to or from the peritoneal cavity,
responsive to a signal from the control unit. A cooling device such
as a peltier cooling device can be operatively coupled to the fluid
reservoir or the infusion member. The cooling device is configured
to cool fluid within, for flowing from the fluid reservoir.
[0020] The pressure source is configured to deliver fluid from the
reservoir through the infusion member and into the peritoneal
cavity. The pressure source can comprise a compressed gas source,
an oxygen pressure source, a compressed oxygen source, a pump or a
gravity generated pressure source (e.g., an I.V bag on a pole). The
vacuum source is configured to provide sufficient vacuum pressure
for removing fluid from the peritoneal cavity and can be generated
by a vacuum pump or can be an external source. The sensor can
comprise a pressure, temperature or flow sensor. The control unit
can be configured for controlling one or more aspects of the
process used to produce hypothermia such as the infusion and
removal of the hypothermic solution, temperature control and
oxygenation of the solution, the infusion pressure and the vacuum
pressure and the total amount of solution infused and removed from
the peritoneal cavity. The control unit can include logic resources
such as a processor, as well as memory resources. The control unit
can also be configured to interface with logic and memory resources
(such as flash memory) coupled to the infusion member or other
system component.
[0021] An exemplary embodiment of a method of using the above
system can comprise inserting the access port or other access
device a controlled depth into an abdominal wall of the patient.
The access port can then be fixed in place as described above. An
infusion catheter or other infusion member can then be advanced
through the access port using an advancement member until the user
receives an audible alarm or other signal indicating the tip of the
infusion catheter has entered the peritoneal cavity, as described
above, so that advancement is stopped before contact with the
peritoneal organs is made, reducing or eliminating the risk or
peritoneal organ injury (Peritoneal injury can also be mitigated
blowing air through the infusion catheter during advancement to
push away any peritoneal organ tissue). The advancement member can
then be removed to render the tip of the infusion catheter
atraumatic. The user can then continue to advance the infusion
catheter a desired amount in the cavity (e.g., to position
catheter, apertures or sensors in the cavity) without the risk of
tissue injury. This can be facilitated by the placement of depth
markings on the catheter shaft.
[0022] The temperature of the patient can then be monitored using
temperature sensors positioned on the infusion catheter, as well as
other locations in the body such as the tympanic membrane, or an
intravenous site. Various hypothermic, nutrient and other solutions
can then be infused into the cavity through the infusion member
wherein an infusion parameter, such as flow rate or total infused
volume, is controlled using the monitored temperature. The
hypothermic solution then cools the peritoneal organs and other
peritoneal tissue so as to reduce the patient's temperature to a
selected level. In various embodiments, the patient's body
temperature can be reduced in the amount of 3, 5, 10.degree. C. or
greater. In preferred embodiments, the patient's temperature can be
reduced to a range between about 32 to 34.degree. C. Temperature
reduction can be done in ten minutes or less depending on the
desired level of cooling and the particular condition to be
treated. Faster rates of cooling can be selected depending upon the
severity of the patient's condition and/or how soon the patient is
first treated after a particular medical event (e.g., heart
attack). Also, a database of cooling rates can be developed and
used which takes into account the particular medical condition,
vital statistics of the patient (e.g., weight and age) and the
estimated time post event (e.g., time from the onset of stroke).
The database can be developed for both populations (e.g., all heart
attack patients) and sub-populations of patients (e.g., those over
65).
[0023] Infusion can be performed in a variety of modes. It can be
done rapidly using a bolus of hypothermic solution, or it can be
done more gradually, or a combination of rapid and slower infusion
modes can be used. In preferred embodiments, a bolus of solution is
infused so as to expand the peritoneal cavity and the space between
peritoneal organs so as to increase the peritoneal tissue surface
area available for heat and mass transfer with the hypothermic or
other solution. In various embodiments, the bolus can comprise
between about 0.5 to three liters of hypothermic solution in the
temperature range from -10 to 20.degree. C. In a preferred
embodiment, about two liters of 4.degree. C. solution is delivered
in about ten minutes or less.
[0024] The delivery of the bolus can be followed by a mode where
fluid is infused at a slower rate and then removed with infusion
and removal rates based on temperatures measured in the peritoneal
cavity and elsewhere in the body. The two modes of delivery can
also overlap. Rates can be controlled through the use of an
automated valve and/or automated pump. Desirably, the infusion and
removal rates are also controlled to keep a sufficient proportion
of the bolus volume in the peritoneal cavity to maintain the cavity
in the expanded state for enhanced heat and mass transfer with the
infused solution. The infusion and removal rates can also be
controlled to assure that there is not overfilling or excessive
pressure buildup within the peritoneal or other cavity. This can be
facilitated by monitoring pressures within the peritoneal cavity
and/or the pressures within the infusion catheter. In other
embodiments, expansion of the peritoneal cavity can also be
achieved through the use of compressed air (e.g., using compressed
gas source 92) in an insufflation technique known in the art to
create a pneumoperitoneum.
[0025] Infusion and removal can be performed concurrently or in a
cycled mode of flow where there is a duty cycle of infusion and
removal periods. The duration of each period and any interval
between can be selected to enhance heat and mass transfer with
peritoneal tissue as well as maintain a desired volume of fluid in
the peritoneal cavity. Also, the periods of infusion and removal
can be synchronized with one or both of heart rate and respiration
to optimize flow rates as well as heat and mass transfer with
peritoneal tissue. For example, infusion can by synchronized with
expiration and/or removal with inspiration. This allows embodiments
of the invention to take advantage of the expansion of the
peritoneal cavity that occurs during expiration to more readily
infuse fluid into the cavity (due to decreased fluidic resistance)
and also the contraction of the cavity that occurs during
inspiration to assist in removing fluid from the cavity. In this
way, embodiments of the invention can use the motion of respiratory
cycles to assist and optimize the inflow and removal of fluids from
the peritoneal cavity. This, in turn, requires reduced power for
the pumping and removal of fluids resulting in a lighter weight
hypothermic infusion system with extended operating life.
[0026] Also in various embodiments, the rate of hypothermic
solution infusion, cooling rate and patient temperature can be
titrated to treat specific medical conditions. For example, cooling
rates and temperatures can be titrated to reduce the amount of
coronary ischemic injury, or cerebral ischemic injury from
myocardial infarction, cardiac arrest, stroke or other
coronary/cerebral ischemic events; or to reduce an amount of
ischemic tissue injury resulting to a tissue extremity. The cooling
rates and temperatures can also be titrated to reduce the amount of
inflammatory response from a surgical procedure such as a
cardiovascular or neural surgical procedure.
[0027] Further details of these and other embodiments and aspects
of the invention are described more fully below, with reference to
the attached drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a schematic view illustrating an embodiment of a
peritoneal hypothermia system.
[0029] FIG. 2a is an elevation view illustrating an embodiment of
the peritoneal hypothermia system applied to a patient with an
infusion catheter and IV temperature sensor.
[0030] FIG. 2b is an elevation view illustrating an attached
peritoneal hypothermia system having a separate outflow collection
bag.
[0031] FIG. 2c is an elevation view illustrating various options
for placement of a temperature sensor on the body.
[0032] FIG. 2d is a lateral view showing a configuration of the
fluid reservoir, cooling device and waste container in which the
waste fluid is used as a heat sink.
[0033] FIG. 2e is an elevation view illustrating an embodiment of a
portable system unit which includes multiple components of a
peritoneal hypothermia system, such as the control unit, fluid
reservoir, waste container and a battery.
[0034] FIG. 3a is a lateral view illustrating an embodiment of the
infusion catheter.
[0035] FIG. 3b is a lateral sectional view illustrating the distal
portion of an embodiment of the infusion catheter having infusion
and removal apertures positioned to reduce clogging by peritoneal
tissue.
[0036] FIG. 3c is a lateral sectional view illustrating the distal
portion of embodiment of the infusion catheter having a longer
length for its infusion lumen than its removal.
[0037] FIG. 3d is a lateral sectional view illustrating the distal
portion of an embodiment of an infusion catheter having
infusion/removal apertures with features to reduce to clogging by
peritoneal tissue.
[0038] FIGS. 4a-b are side and top views illustrating an embodiment
of an access and infusion apparatus including an access device and
infusion catheter advanceable through the access device.
[0039] FIG. 4c is a sectional view illustrating the distal portion
of an access and infusion apparatus having an advancement member
for advancing the infusion catheter.
[0040] FIG. 4d is a sectional view illustrating the proximal
portion of an access and infusion apparatus having an advancement
member with a handle for advancing the infusion catheter.
[0041] FIGS. 5a-5b are lateral views illustrating an embodiment of
an access port having a trocar tip.
[0042] FIG. 5c is a lateral view illustrating an embodiment of an
access port having a hinged tip.
[0043] FIGS. 5d and 5e are lateral views illustrating uses of
embodiments of an access port having a hinged tissue tip (FIG. 5d)
or a retractable tissue penetrating tip (FIG. 5e.).
[0044] FIGS. 5f and 5g are lateral views illustrating uses of an
access port having a shearable tip.
[0045] FIGS. 6a-6e are lateral views illustrating use of an
embodiment of an infusion catheter having a protective sheath.
[0046] FIGS. 7a-7e are lateral views illustrating uses of
pressurized air to prevent tissue injury during catheter
advancement.
DETAILED DESCRIPTION OF THE INVENTION
[0047] Embodiments of the invention provide apparatus, systems and
methods for providing therapeutic hypothermia through minimally
invasive access to the peritoneal cavity. Many embodiments provide
a system for providing hypothermia, resuscitation or other
treatment in response to stroke, myocardial infarction, blood loss
or any condition resulting in decreased perfusion to one or more
locations in the body, including both internal organs and the
extremities.
[0048] Referring now to FIGS. 1-5, an embodiment of a system 10 for
the delivery of hypothermic or other fluid 20 to a peritoneal or
other tissue cavity C which can comprise a main control unit 40, an
infusion member 50 (also referred to herein as an infusion
catheter), an access device 60, a fluid reservoir 70, a waste fluid
container 80, a pressure source 90, a vacuum pressure source 100, a
cooling device 110, and one or more sensors 120 such as temperature
or pressure sensors. In various embodiments, system 10 can be used
to deliver fluids to a number of body cavities such as the pleural
cavity, vagina, intestines, nasal cavity and like structures, as
well as to various vascular structures. Further fluid can be
delivered for purposes of producing hypothermia, post hypothermic
warming, hyperthermia, resuscitation, blood pressure management and
other related treatments. However, for ease of discussion, system
10 will be referred to as a peritoneal circulation or hypothermia
(PH) system 10 and cavity C will be the peritoneal cavity, however
this is for illustrative purposes and it should be appreciated that
other uses and application sites are equally applicable. For
example, embodiments can be readily configured for use in the
pleural cavity through selection of dimensions, shape, materials,
etc.
[0049] FIGS. 1, 2a and 2b show embodiments of system 10 in which
multiple components of the system such as the control unit,
reservoir, etc., are attached to an IV pole or other stand means
150. The proximal end of infusion catheter 50 is coupled to unit 40
and receives fluid 20 from an attached reservoir 70. The distal end
of the catheter is positioned in the peritoneal or other cavity C
of the patient so as to infuse fluid 20 into the cavity. A
temperature or other sensor 120 is connected to the patient at an
IV or other site to measure the patient's temperature. Pole 150
allows unit 40 to be placed at various locations around the patient
and also provides a gravitation head pressure for delivery of fluid
20 into the patient. The pole 150 can be raised or lowered to
provide greater or lesser amounts of head pressure, which can be
sensed via means of a pressure sensor placed in infusion member 50.
After the infusion catheter 50 is positioned at the desired body
cavity site, the infusion (and removal) of fluid 20 can be
initiated either under manual or automated control. The user can
see various data (e.g., patient temperature) on displays 44 and
make one or more adjustments using buttons or other user interfaces
43 or place the unit in an automated mode. Waste fluid can either
be emptied into an external container, as the case in the
embodiment in FIG. 2a, or into an integrated container 80 attached
to pole 150, or another portion of the system. Preferably, waste
container 80 and the connecting tubing are placed below the patient
to provide for removal of fluid using gravitation head pressure
alone (similar to reservoir 70, container 80 can be configured to
be raised or lowered to vary the removal pressure). In such
embodiments, the system can be configured so as to not require a
pressure source 90 or vacuum source 100, but instead completely
rely on gravitation head pressure alone for both functions. Such
embodiments provide an increased measure of portability for field
use since a pressure or vacuum source is required. Particular
embodiments of this configuration can be further adapted for
battlefield or other emergency medicine use through the use of one
or more of light weight weather resistant components, power
efficient and fault tolerant processors and circuitry, rechargeable
high volume efficiency batteries (e.g., lithium or lead acid), and
even the use of light weight manual pumping devices.
[0050] In various embodiments, fluid 20 comprises a solution 20 for
the delivery of a medical treatment such as hypothermic or
resuscitative treatment. For ease of discussion, fluid 20 will be
referred to as solution 20 or as infusate 20. Suitable solutions 20
can comprise various saline solutions (e.g., ringers lactate),
various peritoneal dialysis fluids including nutritive based
peritoneal dialysis fluid (e.g., those containing dextrose and
other sugars), and fluorocarbon solutions configure for oxygen
transport and artificial blood solutions known in the art. For
aqueous embodiments, the solution can also include one or more
freezing point depression compounds (e.g., NaCl) allowing the
solution to be cooled below the freezing point of water to allow
for faster cooling when so desired.
[0051] Also, solution 20 can contain one or more medicaments for
treatment of myocardial infarction, cardiac arrest or other severe
cardiac condition, stroke, shock, reperfusion injury or other
medical conditions. Specific families of medicaments can include
vasoconstrictors, hemolytic compounds (e.g., TPA, streptokinase and
like compounds), anticoagulants, coagulants, calcium channel
blockers, antibiotics, manitols. Also in specific embodiments,
solution 20 can be configured to have resuscitative effects for
treatment of heart attack, stroke, or severe blood loss. It can
also have various agents known in the art for treatment of
reperfusion injury. The delivered amount of a particular medicament
can be titrated to the patient's weight and condition with
titration controlled manually or by a drug delivery module resident
within controller 41. Also, the dose of particular compounds can
both be delivered as a bolus with the initial bolus of hypothermic
solution and also on a continuous basis. The delivery rate of a
particular medicament or group of medicaments can also be
controlled responsive to the patient's temperature, blood pressure,
heart rate or other vital sign monitored manually, by system 10, or
by other monitoring means.
[0052] Solution 20 can also comprise oxygenated solutions such as
oxygenated fluorocarbon solutions that can be configured to deliver
sufficient oxygen to tissue (by gas exchange with peritoneal or
other surrounding tissue) to at least partially meet the oxygen
demands of the body. Flour carbon solutions 20 can be
pre-oxygenated or can be oxygenated in reservoir 70 or outside of
it using oxygen gas sources described herein. Solution 20 can also
include contrast media to allow for imaging by x-ray, MRI,
ultrasound, and other imaging modalities known in the art.
[0053] This main control unit 40 will typically comprise logic
resources 41, memory resources 42, user interface devices 43,
displays 44, control valves 45, fluid connections 46, electrical
connections 47, data input/output ports/interfaces 48, and audio
output devices 49 (e.g., a speaker). The unit can be contained in a
frame or housing 40f and will frequently include a handle 40h for
portability which can be disposed at any point on frame 40f. While
unit 40 can be a standalone unit, it can also be configured to be
readily attached to other components of system 10, such as
reservoir 70, waste container 80, and pressure source 90 as is
discussed herein.
[0054] Displays 44 and user interfaces 43 can comprise a console
face or console device 40c. Console face 40c can be permanently
attached to unit 40; however it may be pivotal in multiple
directions to allow viewing from different angles. In particular
embodiments, it may also be removable, functioning as remote
console 40rc that wirelessly communicates with unit 40. In use,
such wireless embodiments allow the user to operate the system from
any position around the patient, or even to do so remotely. This
provides the user with greater flexibility and ease of use in both
setting up and operating the system, including faster response time
in making system adjustments. For example, if the user sees that
the patient requires immediate attention due to fallen blood
pressure, blood oxygen saturation, etc. or even cardiac arrest,
they can make an immediate adjustment to the system using the
remote console rather than having to rush to reach the control
unit.
[0055] In many embodiments, logic resources 41 can be configured as
a controller for controlling one or more parameters related to a
hypothermic or other treatment regimen, for example, infusate
temperature, body temperature, infusion and removal rates, infusion
and removal pressures, total volume infused and removed and like
parameters. For ease of discussion, logic resources 41 will now be
referred to as controller 41; however, it should be appreciated
that logic resources 41 can be configured to perform a variety of
operations including communicating with external devices including
devices linked over the Internet; data operations; and various
power management functions.
[0056] Controller 41 can include one or both of analog or digital
circuitry for performing its control operations. Controller 41 will
also typically be configured to receive one or more inputs 41i from
sensors 120, pressure source 90, and control valve 45. Typically,
controller 41 will include a computer processor 41p which is
configured to execute one or more electronic instruction sets
contained within a software module or module 42m, which can be
stored in memory resources 42 or controller 41. Additionally,
controller 41 can be configured to be programmed by the user (e.g.,
using unit 40 or by an external device such as a wireless device)
to allow for manual control of one or more operations of system 10
(e.g., infusion rate). Processor 41p can be an off the shelf
processor (e.g., such as those available from INTEL Corporation),
or can be a custom designed ASIC.
[0057] System 10 can include a number of modules 42m which can be
configured to control a variety of operations relating to the use
of system 10, for example, temperature control of the infused
solutions as well as that of the patient, flow and pressure control
of the infused and removed solutions, the level oxygenation of the
infused solution and control of like operations. Modules 42m may
employ algorithms to interpret sensed temperature data to control
fluid flow such that the core temperature of the patient may be
maintained at the desired level. In particular embodiments, modules
42m can control the delivery of solution 20 to achieve or enhance a
particular medical treatment, such a hypothermic treatment. For
example, a module 42m can control the infusion of solution 20 to
enhance the thermal and/or gas exchange of the solution with
peritoneal tissue for a hypothermic and/or resuscitative treatment.
This can be achieved by controlling the infusion of the solution to
control the temperature and pressure within the peritoneal or other
tissue cavity.
[0058] Memory resources 42 can comprise one or more of ROM, RAM,
DRAM and various non-volatile memories including EPROMs and flash
memory. In addition to module 42m, memory resources 42 can also
include a database 42db, which can include one or more treatment
regimens 42tr, such as hypothermic treatment regimen for a
particular medical condition (e.g., stroke) and/or a particular
patient population (e.g., pediatric vs. geriatric). User interfaces
43 can comprise, buttons, keypads, pressure sensitive finger pads,
touch screens and like devices. Control valves 45 can include
various electronic control valves known in the art and are
controlled by controller 41.
[0059] Fluid connections 46 can include Luer lock or other fluidic
connections known in the art and can be configured to be coupled to
one or more of infusion member 50, reservoir 70, container 80,
pressure sources 90 and vacuum source 100. They may also be snap
fit and/or quick disconnect so that the user can quickly reattach a
different infusion member, pressure source, etc. They may also be
color coded for the particular connection (e.g., one color for an
infusion line, another for removal, etc.). They can also have
integrated control valves 45 and/or sensors 120, the latter being
configured to alert the user when the connector has become
disconnected or is otherwise not fully connected.
[0060] Electrical connectors 47 can be configured to be coupled to
one or more wires 47w for coupling to sensors 120, a remote
controller or other like devices. Data input/output ports or
connections 48 can include those known in the portable and computer
arts including PCMCIA connections and UART connections. They can
also include various wireless interfaces/connections including Rf
connections configured for BLUE TOOTH protocol and infrared
interfaces. In specific embodiments, I/O connections 48 can be
configured to interface with an external flash memory or other
external memory device 42e coupled to infusion member 50 or another
component of system 10. This allows control unit 40 to upload and
run one or more modules 42m stored in flash memory coupled to
infusion catheter 50. In use, such embodiments reduce the memory
requirements of control unit 40, and also serve to improve
reliability by not relying on a single memory device which may
become compromised. Thus, the user need only swap out an infusion
catheter 50 (other component of the system carrying a memory
device) rather than swapping out a whole control unit 40.
[0061] Wireless I/O ports 48 can also be configured to wirelessly
communicate with sensors 120 and control valves 45, one or both of
which can include RFID tags. In use, such embodiments reduce the
number of connecting wires required by the system, making it easier
for the medical personnel to position components to the needs of
the patient and the scene, rather than tethering the equipment
around the patient. It also allows the user to quickly reposition a
temperature or other sensor 120, without having to stop to
disconnect and reconnect the sensor.
[0062] Sensors 120 can be configured to measure a variety of
physical properties related to the use of system 10. Accordingly,
they can comprise a variety of biomedical sensors known in the art,
including temperature sensors, pressure sensors, force sensors,
flow sensors, pH sensors, oxygen and other gas sensors (e.g.,
CO.sub.2), acoustic sensors, piezoelectric sensors, and the like.
Suitable temperature sensors can include thermisters,
thermocouples, optical sensors, and like devices. Suitable pressure
and force sensors can include strain gauges, solid state, and mems
based strain gauges. Suitable flow sensors include electromagnetic
flow sensors and aneometric flow sensors known in the art.
Temperature, pressure sensors and flow sensors positioned on
infusion member 50 and include one more miniature thermisters, and
solid state pressure sensors and flow sensors known in the art. One
more sensors 120 can also include RFID tags or like devices so as
to be able to wirelessly signal an input to controller 41 or
another instrument.
[0063] A discussion will now be presented of infusion catheter 50.
In various embodiments, infusion catheter 50 can be configured to
be positioned in the peritoneal PC or other tissue cavity C and
deliver fluid to the cavity for a hypothermic or other medical
treatment discussed herein. Typically the infusion member will be
advanced through an access device 60 which is inserted to a
controlled depth into the abdominal or other tissue wall. The
infusion catheter can be configured to be advanced by itself or
through use of an advancement member 30 discussed herein which can
be reversibly positioned in a lumen of the infusion member and acts
to increase the pushability or column strength of the infusion
member when so positioned.
[0064] In many embodiments, infusion member 50 will comprise a
catheter, so for ease of discussion, infusion member will now be
referred to as catheter 50. The catheter can have a length ranging
from 20 cm to 200 cms to allow for connection to unit 40 at varying
distances from the patient. Smaller lengths can be used for
pediatric application. The outer diameter 50D of the catheter can
be sized for advancement through standard surgical port access
devices and in varying embodiments, can range from about 0.1 to 1
inch though other sizes are also contemplated depending upon the
target tissue site. For example, smaller sizes can be used for
accessing the pleural cavity as well as for pediatric applications.
Various embodiments of the catheter can include insertion depth
indicia 50di and or radio-opaque/echogenic markings 50m in order to
assist in determining insertion depth either visually or under
image guidance (e.g., fluoroscopy, ultrasound, etc.).
[0065] Catheter 50 can include at least one lumen 51, extending all
or a portion of its length 50L. Typically, the catheter will
include at least a first lumen 52 for infusion of infusate 20 and a
second lumen 53 for removal of fluid, though additional lumens are
also contemplated. Typically, the lumens will be round or oval
shaped, but can also be D-shaped or crescent shaped. In various
embodiments, the inner diameters 52id and 53id of lumens 52 and 53
can range from about 0.05 to about 0.5 inches though other
diameters are also contemplated. Desirably, lumen 52 has a
sufficient inner diameter 52id to be able to infuse 2 to 4 liters
of hypothermic infusate 20 to reduce the patient's body temperature
by at least about 3.degree. C., or more preferably, ten minutes or
less via heat exchange with peritoneal tissue using pressures less
than 3 atmospheres and more preferably less than 1 atmosphere.
Diameter 53id is also desirably configured to deliver between 2 to
4 liters of infusate 20 in ten minutes or less. Diameter 53id can
be configured to remove similar volumes of fluid in similar time
periods. In addition to fluid infusion and removal, one or both
lumens 52 and 53 can be sized for advancement of an advancement
member, guidewire, endoscope or other viewing device, a sensing
member, tissue biopsy device, or other minimally invasive surgical
device.
[0066] In preferred embodiments, infusion lumen 52 will extend the
entire length of the infusion catheter. The removal lumen 53 is
desirably not continuous to the very tip of the infusion catheter
to allow for an advancement member 30 (described herein) to have a
surface to push against so as to advance the infusion catheter.
Alternatively, the inner diameter 53id of removal lumen 53 can neck
down near the distal end of the infusion catheter so as to be able
hold the advancement member by an interference fit.
[0067] In a preferred embodiment, lumens 52 and 53 are contained in
a single catheter 50 for its entire length such as in a single dual
lumen catheter. However, in various embodiments, the catheter 50
can split up a point 59 into separate portions 50i and 50r
containing the infusion and removal lumens to provide for easy
connection to reservoir 70 and waste container 80 as is shown in
FIG. 2b. Also, the distal infusion and removal portions 52p and 53p
can extend different lengths. In FIG. 2a, portion 52p can extend
past portion 53p as discussed in further detail herein. FIG. 2b
illustrates a reverse configuration.
[0068] Catheter 50 will also typically include one or more
apertures 54 positioned along catheter distal portions 57 for the
outflow 54o and inflow 54i of fluid to provide for the infusion and
removal of fluid from the peritoneal or other cavity C. Typically,
the outflow or infusion apertures 55 will be placed more distally
than inflow or removal aperture 56 to reduce the pressure for
removal, and reduce the immediate uptake of the infused solution by
removal apertures 56. Both types of apertures can be positioned in
patterns 55p and 56p to reduce clogging by peritoneal tissue and
improve flow rates in both directions. Typically, this involves a
minimal amount of spacing between each aperture (e.g., 1 mm or
greater). Further resistance to the tissue clogging of outflow and
inflow apertures 55 and 56 can also be achieved by moving at least
some of the outflow apertures off of tip 57t and placing the inflow
aperture even more proximally with respect to the catheter tip (for
example, several centimeters or more) as is shown in FIG. 4b. In
preferred embodiments, this can also be achieved by extending the
portion 52p of the catheter containing infusion lumen 52 several
centimeters more distally than the catheter portion 53p which
contains removal lumen 53 as is shown in FIGS. 2a and 3c. The
transition 53t between the two portions is desirably tapered to
provide for smooth advancement of the catheter. In still other
embodiments, one or both sets of apertures 55 and 56 can include
protective features 54f such as a protective porous membrane 54fm,
surrounding the apertures 56 or a protective lip or baffle 54fl
overlying at least a portion of apertures 55 as is shown in FIG.
3d. The lip or baffle 54fl is desirably configured to direct away
tissue encroaching from the distal direction, but still allow
inflow from the proximal direction. These features can be placed on
either sets of apertures 55 and 56.
[0069] Catheter 50 will typically include one or more sensors 120
which can be selected to measure: flow rates, pressure, temperature
or other physical property. In preferred embodiments, the catheter
will include at least one temperature sensor positioned on the
distal portion or even the distal tip 57t of the catheter to
measure temperature within the peritoneal or other cavity. The
input from temperature sensor 120 can be utilized by controller 41
and/or a thermal regulation module 41m to regulate infusate flow
rate and the infusate temperature, so as to reduce the patient's
temperature a selected amount as part of a hypothermic treatment
regimen. Multiple temperature sensors may be placed at various
locations on the catheter to obtain a composite temperature over a
volume of the peritoneal or other cavity. Temperature sensors 120
can also be placed within lumens 55 and 56 to monitor the
temperature of infused and removed fluid.
[0070] In addition to temperature sensors 120 placed on catheter
50, various external temperatures sensors 120e may be placed in one
or more locations in body. FIG. 2c illustrates the various
placement options for temperature sensors 120e which can in some
embodiments be wireless based sensors known in the art. Such
placement options can include peritoneal PC, intravascular I,
auricular A, oral O, epidermal ED and rectal/urethral RU. In
preferred embodiments, peritoneal and/or intravascular temperature
can be used for control purposes. However, in various embodiments,
temperatures can be sampled from multiple locations and a composite
temperature can be developed and used for control purposes, with
assignable weightings to each location. In use, a composite
measurement can give a more accurate reflection of the patient's
temperature particular during fast cool regimens. In these
embodiments, a temperature map can be developed and displayed to
show the progress of cooling over the patient's body (e.g., as a
wave or depth of cooling). In other embodiments, only temperature
measurements from a particular target site to be cooled can be
used, e.g., the peritoneal cavity.
[0071] Catheter 50 can also include at least one flow sensor 120
positioned in lumen 55. Flow sensors 120 positioned in lumen 55 can
be configured to perform several functions. First, to provide an
input to controller 41 for controlling infusate flow rate. Second,
to provide an input to the controller indicating the entry of the
distal tip of the catheter into the peritoneal or other tissue
cavity so as to minimize the risk of injuring a peritoneal organ or
other tissue. This latter function can be achieved through use of
entry point detection module 41 which detects entry by an increase
in infusate flow rate which occurs when the tip of the catheter
emerges into the peritoneal cavity and one or more infusion
apertures become patent. In such embodiments, the pressure source
90 can be configured to provide at least a minimal pressure to the
infusion lumen during catheter advancement for purposes of
detecting flow. Entry can be detected by an absolute increase in
flow rate or a rate of increase or a combination of both (i.e.,
analogous to PD control). Once entry is detected, controller 41 can
send an audio alarm signal to audio output device 49 to alert the
user that entry has occurred. In one embodiment, a series of
pre-alarm signals may also be sent indicating when the entry point
is close (e.g., one aperture has entered the cavity) so as to
provide the user with more advance warning of entry.
[0072] Catheter 50 can also include one or more pressure sensors
120 positioned at various locations on or within the catheter. In
particular embodiments, pressure sensors 120 can be positioned in
lumen 55 to detect entry of infusion catheter into the peritoneal
or other cavity, as described above. However, in this case, entry
is detected by a decrease in pressure either absolute or rate of
decrease. In another application for the use of pressure sensors,
the pressure sensor 120 can be positioned on a distal portion of
the catheter, such as tip 57t to detect the pressure in the
peritoneal or other cavity C. This pressure signal can then be
utilized by controller 41 to decrease or shut off infusion when the
measured peritoneal cavity pressure exceeds a selected absolute
threshold or rate of increase. The controller can also send an
accompanying alarm signal to speaker 49. Desirably, the controller
is configured to slow down the infusion rate as the selected
pressure threshold is reached rather than shutting off infusion
altogether. In use, such embodiments prevent or reduce the
likelihood of over-pressurizing the peritoneal cavity. They also
serve to optimize the rate of patient cooling (since the system
need not be shut off to respond to over pressurization events) and
allow the system to be run in a more automated fashion with less
oversight by the user.
[0073] Catheter 50 can be fabricated from various biocompatible
flexible polymers known in the art such as polyethylene (HDPE and
LDPE), silicone, polyurethane, PTFE, PEBAX and like materials. All
or a portion of the catheter can include a lubricous coating 50c
such as a silicone coating to assist in advancement of the catheter
through tissue. Also, the tip 57t or distal portions 57 can be
tapered. The catheter can also include braiding or other means for
improving kink resistance and increasing the burst strength of the
catheter lumens. In particular embodiments, the proximal portions
58 of the catheter can be braided or otherwise stiffened such that
the catheter has sufficient column strength to be advanced into the
peritoneal cavity through manipulation of the proximal portion 58.
In some embodiments, the catheter can include a handle (not shown)
positioned at proximal end 58e of the catheter to assist in
advancement of the catheter.
[0074] In many embodiments, infusion catheter 50 is configured to
be advanced into a tissue cavity through use of an access device
60. Access device 60 is configured to penetrate a selectable
distance D through the skin S and into sub-dermal tissue layers
SDL. The infusion catheter 50 is then advanced through a lumen of
the access device into the peritoneal PC or other cavity C as is
described herein. In this respect, access device 60 functions as a
port for the introduction and advancement of infusion member 50
into tissue. Collectively, infusion catheter 50 and access device
60 can comprise an access and infusion apparatus 68 which can be
sterilely packaged as a kit separate from other components of
system 10, such that the apparatus can be readily stored and
transported separate from unit 40 or 140. This helps to maintain
the sterility of the entire system. The catheter and access device
of apparatus 68 are sized to be used together so that the user need
not match the size of the catheter to that of the access device.
However, other embodiments are contemplated where the catheter and
access device are packaged separately so they can be mixed and
matched. In the latter case, matching infusion catheters 50 and
access devices 60 can be color coded for ease of matching.
[0075] In various embodiments, access device 60 will typically
include at least one lumen 61 extending there through and a tissue
penetrating distal end 62. Lumen 61 can have an inner diameter 61D
sized to accommodate a variety of different sized infusion
catheters 50 and in various embodiments can range from about 0.1 to
0.5 inches, though other sizes are also contemplated. Access device
60 can be a surgical port device, trocar or other surgical access
known in the art. Access device 60 will typically have a stop 64 to
control the penetration depth of the access device into the tissue
so that user does not need to precisely control the insertion
depth. Stop 64 can comprise a flange or lip that protrudes from the
outer walls of the access device and is positioned close to
proximal end 63. Stop 64 can also include an adhesive 65 and/or a
suture opening 66 for affixing the access device to the skin
surface once it is inserted. Desirably, adhesive 65 has sufficient
adhesive force and area to laterally stabilize the access device on
the skin surface. The stop 64 can also be adjustable (e.g., using
screws or an indexing mechanisms) to control the penetration depth
D of the access device into the tissue. In preferred embodiments,
the access device is configured to penetrate into sub-dermal tissue
layers SDL, but not completely through abdominal or other tissue
wall TW. The access device can be fabricated from various
biocompatible rigid polymers and metals known in the art, it can
also include indicia along its length indicating penetration
depth.
[0076] Tissue penetration tip 62 can have a variety of tissue
penetrating shapes including a trocar tip shape 62c as is shown in
FIGS. 5a-5b. In many embodiments, the distal end 62 of access
device 60 can also be transformable from a tissue penetrating
configuration 62t to a non-tissue penetrating 62s or safety
configuration. This can be achieved through a variety of means. For
example, in one embodiment, the distal end can be hinged as is
shown in FIGS. 5c and 5d such that once the access device reaches
its stop depth, advancement of the infusion catheter forces the
hinged blades 62b open or through a spring-loaded mechanism which
provides for the blades to spring away from the lumen once an
appropriate amount of incision has been achieved. In another
embodiment shown in FIG. 5e, the distal end can be retractable
through use of spring loaded or like mechanism. In another
embodiment shown in FIGS. 5f-g, distal tip 62 of access device 60
can be a shearable tip 62h, for example by advancement of catheter
50, such that the catheter 50 breaks through tip 62 and once
sheared, renders it a blunt non-tissue penetrating tip now in the
safety configuration. Distal tip 62 can be configured to be
shearable through the use of notching or other weakening features
or treatment or through the use of dimensioning (e.g., wall
thickness) to more readily shear when an axial force is applied by
catheter 50 and/or advancement member 30. In another embodiment
(not shown), access device 60 can be put into the safety
configuration through the use of an overlying slidable sheath that
slides over device 60 once the penetration depth is achieved
through use of stop 64 or other penetration limiting means.
[0077] Infusion catheter 50 can be advanced into tissue by
different means. As described above, in some embodiments, the
catheter can have sufficient column strength to advance into tissue
by manipulation of a proximal portion of the catheter without any
additional support. In these embodiments the catheter tip is
configured to be tissue penetrating, without external support.
However, in preferred embodiments, the catheter is configured to
advance through means of advancement member 30 which is removably
positionable in at least one of the lumens 51 of infusion catheter
50 to advance the catheter in a distal direction 33 through the
abdominal or other tissue wall. In these latter embodiments,
catheter tip 57t is tissue penetrating when supported by
advancement member 30, but upon removal of the advancement member,
the tip becomes a substantially atraumatic tip 57ta. This can be
facilitated by constructing the catheter tip from flexible polymer
material as well as tapering the tip. The use of an atraumatic tip
57ta allows the user to continue to advance the catheter 50 into
the peritoneal or other cavity C in order to position apertures 55
and 56 at a desired location as well as take temperature readings
in multiple locations without risk of injury to the peritoneal
organs. It also allows the catheter to be readily repositioned
without risk of similar injury.
[0078] In many cases, the advancement member will be sized for
advancement in the removal lumen 53 or other lumen besides infusion
lumen 52 so as to allow for the infusion of solution 20 through the
catheter during catheter advancement to detect entry of the
catheter tip into the peritoneal cavity using techniques described
herein. While in many cases it will be sized to be removably
positioned in catheter 50, in other embodiments it can also be
fixed in position within the catheter.
[0079] Desirably, the advancement member has sufficient column
strength to advance infusion catheter 50 through the abdominal wall
AW or other tissue TW and into the peritoneal PC or cavity C by
manipulation of a proximal portion 58 of the infusion member or a
proximal portion 31 of the advancement member. In addition to
having sufficient column strength to advance the infusion member,
the advancement member can also be configured to be able to have
sufficient column strength to push through or shear embodiments of
access device that have a shearable distal portion 62h.
[0080] In preferred embodiments, the advancement member can have a
handle or grip 30h positioned at its proximal portion 31 to
facilitate manipulation by the user. In an embodiment shown in FIG.
4D, the handle 30h can be configured along the proximal portion of
catheter 50 to having gun like grip 30g allowing the user to hold
the catheter by grip 30g and advance the advancement member in a
distal direction 34 using only their thumb. In such embodiments,
the proximal portion 58 of the catheter can be directed downwards
forming a gun-like handle shape 50g that can be held in the user's
hand
[0081] As described above, the advancement member will be
positioned in the removal lumen 53 of the infusion catheter so as
to allow for flow of solution 20 through the infusion lumen 52
during advancement of the infusion catheter. In order to prevent
fluid from leaking out of the removal lumen in the space between
the removal lumen walls and the advancement member, the infusion
catheter can have an adjustable valve 37 positioned around the
advancement member to form a fluidic seal around the advancement
member during movement of member 30 or when stationary. In a
preferred embodiment, valve 37 can comprise a Touhy-Borst type
adapter known in the art and include a single or a multi arm
adapter to allow for multiple connections (e.g., to waste container
80 as well as to one or more biomedical monitoring
instruments).
[0082] Valve 37 can also be configured to fluidically seal the
proximal end of the removal lumen when the advancement member is
not in place. Adjustable valve 37 can be configured to not only
form a fluidic seal around the advancement member but also to hold
the advancement member in place within infusion catheter. This
allows the user to selectively position the advancement member in
the infusion catheter during advancement of the latter. This
positioning in turn can allow the user to select the amount of
flexibility or stiffness of the distal portions of the infusion
catheter.
[0083] The advancement member can have a variety of lengths
depending upon the application and the length of infusion catheter
50. In preferred embodiments the advancement member has a length
such that the proximal end 31e of the advancement member extends
past the proximal end 58e of the infusion member (when fully
inserted into the infusion member) so that proximal end of the
advancement member can be readily manipulated by the user. The
diameter 34 of the advancement member is sized such that it can be
readily advanced or withdrawn from the infusion member with minimal
or in some cases slight resistance. In other cases, member diameter
34 can be sized to have some resistance with lumen 53 of infusion
catheter or even to result in an interference fit within the
lumen.
[0084] In various embodiments, the advancement member can be
fabricated from various biocompatible metals such as stainless
steel or rigid polymers known in the art (PEEK, polyamides,
polyimides, polyetherimide and like materials). The material of the
advancement member together with its diameter are desirably
selected to meet column strength described above. The material for
the advancement member can also be selected to have a lubricous
surface 35 or be coated with a lubricous coating 35c, such as
silicone or TEFLON, to facilitate advancement of the advancement
member in the infusion catheter. Additionally, all or a portion of
the advancement member can comprise a radio-opaque material
(including a distinct marking) for visualization under various
medical imaging modalities.
[0085] Cooling device 110 can comprise various cooling devices
known in the art including electronic cooling devices, chillers,
cryogenic gas based cooling devices and the like. In preferred
embodiments, cooling device 110 comprises a peltier cooling device
111 which can be placed within, adjacent to, or is otherwise
thermally coupled to reservoir 70 so as to form cooling assembly
115 as is shown in FIG. 2d. Assembly 115 can include volume
measurement indicia 115m, one or both of reservoir 70, and
container 80 to indicate the fill state of either. It may also
include insulation 115i around all or a portion of its surface
including the surface of reservoir 70 and container 80. The
assembly 115 can include a handle 115h and can be modularized such
that it can be reversibly coupled to control unit 40 and/or system
unit 140. It can also be configured to be stored in a refrigerator
with a filled reservoir 70 such that it can be removed and quickly
connected to unit 40/140. In use, such embodiments allow for the
immediate infusion of a hypothermic solution 20 without having to
wait for a cool down period. Similar results can be achieved by
modularizing reservoir 70 such that it can be pre-refrigerated and
quickly connected to assembly 115 and/or unit 40/140. Such
modularity can be facilitated by the use of quick fluidic
connections, such as snap fit connections known in the art,
allowing assembly 115 or reservoir 70 to be easily snapped in
place.
[0086] In preferred embodiments, peltier device 111 is placed
between reservoir 70 and waste container 80 such that cooling side
112 of device 111 is thermally coupled to reservoir 70 and the hot
side 113 is so coupled to waste container 80. This configuration
allows device 111 to readily extract heat from and thus cool the
fluid in reservoir 70 and also use the fluid in waste container 80
as a heat sink since that fluid in waste container 80 will still be
below the temperature of hot side 113. One or more temperatures
sensors 120 can be placed in reservoir 70, container 80, as well as
on peltier device 111, so as to send input signals 41i to
controller 41. Controller 41 can use these signals to optimize the
cooling process using various control algorithms (e.g., PID, PI,
etc.) embedded within a thermal control module 41m. These and
related embodiments allow for rapid and continuous cooling of
infused fluid 20 with reduced cooling power requirements. In
various embodiments, the assembly can also include a supplemental
cooling device 110s to provide for faster cooling rates.
Supplemental device 110 can be peltier or other cooling devices
described herein.
[0087] In many embodiments, unit 40 can be integral or otherwise
coupled to one or more of reservoir 70, waste container 80, pump or
other pressure source 90, and cooling device 110 so as to comprise
a system unit 140. System unit 140 is desirably a portable unit and
will typically include a handle 140h and is sized to be readily
carried and transportable in an ambulance, EMT vehicle, crash cart
and the like. Unit 140 can also include brackets or other mounting
means to be quickly mounted to an IV pole 150 or like structure.
Unit 140 may also include an integral IV pole 150 as is shown in
FIG. 2e. Pole 150 may be telescoping or otherwise self-expanding.
Unit 140 can include an integral battery 160, such as a
rechargeable lead acid battery having sufficient capacity for
multiple hours of operations. The unit can also include electrical
power connections 47p for connection to an external power supply
161 which can be either an AC or DC power supply 162 and 163
respectively.
[0088] Pressure source 90 is desirably configured to provide
sufficient pressure for fluid flow from reservoir 70 through
catheter 50 and into cavity C. In various embodiments, pressure
source 90 can comprise an infusion pump including a positive
displacement pump or a peristaltic pump. It can also be configured
to interface with a pump cassette portion 51 of catheter 50 such
that the pump does not need to contact fluid 20. Pump 91 can also
be configured as a vacuum source 100 by pumping in an opposite
direction. Pump 91 or other pressure source 90 (e.g., a gas source
described below), desirably provides sufficient pressure to infuse
2 to 4 liters of solution 20 into the peritoneal cavity of a
patient in ten minutes or less. Pump 91 is desirably automated and
can send and receive one or more inputs from controller 41. In
particular embodiments, pump 91 can be configured to produce
pulsatile flow (for either infusion or removal of solution) and can
include a selectable pressure and/or flow wave form such as
sinusoidal, square wave and like waveforms. The period of the
waveform can also be synchronized with one or more of heart rate,
respiration as is described herein. In one embodiment, infusate
flow can be counter-pulsated (e.g., approximately 180.degree. out
of phase) with the heart rate so as to increase blood flow through
the peritoneal vasculature and provide a measure of pumping
assistance to the heart. In related embodiments, such counter
pulsation or other forms of synchronized flow can also be used to
increase the patient's blood pressure (by producing
vasoconstriction within the peritoneal and surrounding vasculature)
for treatment of patients suffering blood loss, shock or other
conditions causing low blood pressure. In various embodiments, the
waveform and periods of infusion and removal, as well as
synchronization, can be controlled by a duty cycle module 41m
executed by controller 41. Synchronization can be achieved through
inputs of one or more sensors 120, as well as inputs from external
biomedical monitoring instrumentation.
[0089] In other embodiments, pressure source 90 can comprise a
compressed gas source 92, such as a compressed air source. The
compressed gas source will typically include a control valve 94
which can be an electronic valve operably coupled to controller 41.
Control valve 94 (or other control valve 45) and controller 41 can
also be configured to produce the forms of pulsatile and
synchronized flow and related waveforms described above for pump
91.
[0090] In preferred embodiments, gas source 92 is a compressed
oxygen source 93 which can be externally coupled oxygen source or
an integral source coupled to unit 40 or 140. Compressed oxygen
source 93 is desirably configured to provide sufficient total
pressure for fluid flow into cavity C. It is also desirably
configured to have a sufficient oxygen partial pressure to
oxygenate infused solution 20 so as to be able deliver sufficient
oxygen to peritoneal or other tissue to help increase the blood
oxygen saturation of a hypoxic patient.
[0091] Oxygen source 93 can be coupled to oxygenation element or
device 95 such as a bubble oxygenator or hollow fiber oxygenator.
Oxygenation device 95 can be positioned within reservoir 70, an
oxygenation chamber fluidically coupled to reservoir 70, or within
a lumen of infusion catheter 50. The flow of oxygen into solution
20 can be controlled through the use of one or more oxygen sensors
120 positioned within reservoir 70, or infusion catheter 50.
Controller 41 can receive one or more feedbacks from these sensors
to regulate the oxygen saturation of solution 20 using an oxygen
control module 42m which uses one or more control algorithms, e.g.,
PID, etc. Also, multiple oxygen sensors can be externally placed
along the length of infusion catheter 50 in order to measure oxygen
partial pressures within different locations within the peritoneal
PC or other cavity C as well as a rate of oxygen uptake by
peritoneal tissue. Such measured oxygen partial pressure can be
utilized together with measured peritoneal pressures and
temperatures to more precisely control the infusion and removal of
solution from the peritoneal cavity for a hypothermic,
resuscitative, dialysis or other medical treatment using an infused
solution.
[0092] Referring now to FIGS. 6a-6e and FIGS. 7a-7e, several
alternative embodiments for preventing peritoneal injury during
advancement of infusion catheter 50, will now be discussed. In
these embodiments, the catheter can include an unsupported tissue
penetrating tip 57tp, which can comprise a needle or other sharp
tip. They can also be utilized with embodiments where the catheter
is advanced through use of advancement member 30 and is tissue
penetrating when supported by the advancement member. In an
embodiment shown in FIGS. 6a-6e, catheter 50 can include a slidable
protective sheath 50s which allows the tissue penetrating tip 57tp
of the catheter to penetrate the skin S and subcutaneous tissues
layers STL but will not penetrate the bowel B. Once exposed to the
tension of the skin and subcutaneous tissues, the sheath 50s is
retracted proximally exposing tip 57tp so that it can pierce the
underlying skin and other tissue. Once this tension is relieved
though, the sheath springs back over the tip, thereby protecting
the bowel. A temperature sensor 120 can be positioned near the tip
to detect movement of the sheath (by detecting a change in
temperature when this occurs), as well as measure temperature in
the peritoneal or other cavity.
[0093] In another embodiment shown in FIGS. 7a-7e, pressurized air
flow through the catheter 50 can be employed to prevent organ
injury during advancement. The air or other fluid 20 is channeled
through a lumen 52 to the tissue penetrating tip 57tp of catheter
50. Once inserted subcutaneously (see FIG. 7c) the air or fluid is
urged forward, but is incapable of flowing due to the resistance
from encroaching subcutaneous tissue ST. Once the needle enters the
peritoneal cavity PC though, the bowel B will be moved away from
the tip 57tp, creating a gap G, due to the pressurized air fluid
forcing it away as is shown in FIGS. 7d and 7e. Desirably, gap G is
of sufficient distance such the tip 57tp will not contact the bowel
or other peritoneal tissue during movement or repositioning of the
catheter. The Gap can be monitored under image guidance or through
a sensor 120 and the pressure of fluid 22 can be adjusted to
maintain or change the gap distance at the user's preference.
[0094] In various embodiments of methods of using the invention,
system 10 can be used to cool the patient's body temperature at
different rates and different temperatures. Generally, though not
necessarily, the patient's body temperature that is cooled is
considered to be their core temperature. However, in some
instances, system 10 can be configured to produce a more localized
cooling effect or otherwise preferentially cool a particular
targeted region of the body to a particular temperature (e.g., the
peritoneal region), or even a particular organ (e.g., the heart),
or an extremity (e.g., the leg) without necessarily bringing the
patients core temperature to that level. This can be facilitated by
placement of one or more sensors 120 at the target tissue site to
be cooled (e.g., in the peritoneal cavity, or a needle sensor
inserted into the extremity).
[0095] System 10 can be used to produce a particular hypothermic or
cooling regimen (e.g. rate of cooling and target temperature). The
cooling regimen can be titrated to treat a variety of medical
conditions including stroke, myocardial infarction, blood loss or
any condition causing reduced perfusion to the brain, heart or any
of the major organ systems, e.g. the kidneys, gastro-intestinal,
system, etc., as well as any extremity, e.g., arm, leg, etc. In
particular embodiments, the cooling regimens can be employed to
treat particular conditions e.g., stroke vs. myocardial infarction
so as to reduce the amount of ischemic reperfusion injury to vital
organs resulting from the particular ischemic event. In specific
embodiments, the cooling regimen can be configured to do one or
more of the following: i) reduce coronary infarct size and related
sequelia from various cardiac events such as acute myocardial
infarction, cardiac arrest, arrhythmia, trauma or other cardiac
insufficiency; ii) reduce cerebral infarct size and related
sequelia from stroke, cerebral vessel dissection, head trauma,
cardiac arrest, arrhythmia, blood loss or other cardio-pulmonary
insufficiency; iii) reduce tissue injury in other vital organs from
cardiac arrest, blood loss or other cardio-pulmonary insufficiency;
iv) reduce tissue injury in an extremity (e.g., the leg) resulting
from trauma or blood loss; v) reduce post-surgical tissue
inflammation; and vi) provide a tissue protective effect from
reduced perfusion resulting from surgery or other medical
procedure.
[0096] In various embodiments, the cooling regimen can be selected
by the user from a database of cooling regimens 42db stored memory
resources 42 or an external device or computer wireless interfaced
to system 10. The database of cooling regimens can include regimens
for particular conditions, e.g., myocardial infarction as described
above. The user can select a regimen from the database and use it
unmodified or may customize, or otherwise fine-tune it to the
particular patient and his/her current condition. This can be done
by adjusting one more treatment parameters such as infusion rate,
infusate temperature, etc.
[0097] System 10 can be configured to cool the temperature to a
variety of ranges. In many embodiments, the system can be used to
cool the patient's temperature in the range of about 30 to about
35.degree. C., with a preferred target temperature of 34.degree. C.
Lower ranges can also be selected depending upon the medical
condition or surgical procedure. In embodiments for treatment of
acute myocardial infarction or stroke, system 10 can be configured
to cool the patient's temperature the targeted value (e.g.,
34.degree. C.) in ten minutes or less. In many embodiments, this
can be achieved by rapidly infusing a bolus of chilled solution
into the peritoneal cavity preferably between 2 to 4 liters and
more preferably about 3 liters in ten minutes or less. Shorter
periods such as five minutes or less are also contemplated and can
be achieved through use cooler infusion solutions including
solutions cooled below 0.degree. C. Faster cooling can be achieved
by infusing cooler solution and/or high infusion rates. Higher flow
rates can be achieved through the use of higher pressure or larger
lumen diameters for the infusion catheter 50. In particular
embodiments, the lumen diameter of the infusion catheter can be
configured for delivering a maximum flow rate and the medical care
provider can select the infusion catheter for its maximum flow rate
so as to able deliver a desired amount of hypothermic solution 20
for a particular medical condition.
[0098] Also in various embodiments, system 10 can be used to cool
all or a selected portion of the patient's body prior and
post-surgery to reduce a patient's inflammatory response resulting
from the surgery due to the release of cytokines, etc. In related
embodiments, system 10 can be used for pre-operative and
intra-operative cooling of a selected operative site, such as the
heart, to allow for extended periods of operation on the organ with
reduced or no perfusion through the organ. In one embodiment, the
system can be configured to chill the heart (similar to
cardioplegia) to allow for various forms of cardiac surgery, which
may require the heart to be stopped or where portions of the heart
are cross clamped, such as valve replacement, CABG, aorta repair,
atrial-septal defect repair and like procedures. This can be
achieved through cooling of the peritoneal cavity, or by direct
infusion of cooling solution to a chamber of the heart using a
cardiac type port access device 60 known in the art.
[0099] In such embodiments, system 10 can be configured to achieve
coronary tissue temperatures in the range of about 20 to 25.degree.
C. or an even lower range for example 10 to 20.degree. C. Lower
temperatures can be selected and titrated for longer periods of
cardiac arrest or reduced coronary perfusion. For example, for
periods of cross clamping less than 60 minutes, a 20 to 25.degree.
C. range can be selected, while for periods in excess of 60 minutes
a 10 to 20.degree. C. range can be selected. Also, the system can
be used to a provide a pre-operative period of hypothermic
treatment, also known as pre-ischemic conditioning, to extend
operating time and reduce an amount of post-operative cardiac
reperfusion injury.
CONCLUSION
[0100] The foregoing description of various embodiments of the
invention has been presented for purposes of illustration and
description. It is not intended to limit the invention to the
precise forms disclosed. Many modifications, variations and
refinements will be apparent to practitioners skilled in the art.
For example, embodiments of the apparatus and related methods can
be configured for performing hypothermic treatments at a number of
access points in the body including the abdominal, thoracic, spinal
and cerebral regions. Embodiments of the apparatus can also be
sized or otherwise adapted for pediatric and neonatal
applications.
[0101] Elements, characteristics, or acts from one embodiment can
be readily recombined or substituted with one or more elements,
characteristics or acts from other embodiments to form numerous
additional embodiments within the scope of the invention. Moreover,
elements that are shown or described as being combined with other
elements, can, in various embodiments, exist as standalone
elements. Hence, the scope of the present invention is not limited
to the specifics of the described embodiments, but is instead
limited solely by the appended claims.
* * * * *