U.S. patent application number 12/917162 was filed with the patent office on 2011-02-24 for multilumen catheter.
This patent application is currently assigned to Medtronic MiniMed, Inc.. Invention is credited to Bradley J. Enegren, Victor Giron, Rebecca Gottlieb, Michael E. Miller, Mary M. Morris, Rajiv Shah.
Application Number | 20110046457 12/917162 |
Document ID | / |
Family ID | 27792162 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110046457 |
Kind Code |
A1 |
Gottlieb; Rebecca ; et
al. |
February 24, 2011 |
MULTILUMEN CATHETER
Abstract
A multilumen catheter having tubings extending into lumens
within the catheter. The lumens may be used for blood, drugs or
other medicants. The lumens may also be used for sensors. The
junction element, external to the patient, connects the tubings to
the lumens. The tubings, also external to the patient, connect to
infusion members, to which one or more infusion systems may be
connected to deliver blood, drugs and other medicants to the
patient. A sensor having a sensing element may extend through the
sensor lumen and be positioned internal to the patient for
physiological parameter sensing. An external portion of the sensor
may be connected to associated electronics to provide automatic
monitoring of the physiological parameters and automatic delivery
and control of the infusants. Also, a central line catheter for
delivering fluids directly into a main artery or vein near the
heart, which contains a first lumen to deliver a fluid through the
central line catheter and a second lumen containing a sensor
capable indicating a characteristic level in blood. The first lumen
delivers the fluid downstream of the sensor to prevent any
interference between the fluid delivery and the sensor readings. In
other versions, the central line catheter can have additional
lumens for additional purposes. In addition, the central line
catheter can further include a flush sleeve to remove debris around
the sensor.
Inventors: |
Gottlieb; Rebecca; (Culver
City, CA) ; Shah; Rajiv; (Rancho Palos Verdes,
CA) ; Morris; Mary M.; (Mounds View, MN) ;
Giron; Victor; (North Hills, CA) ; Miller; Michael
E.; (Los Angeles, CA) ; Enegren; Bradley J.;
(Moorpark, CA) |
Correspondence
Address: |
Foley & Lardner LLP
555 South Flower Street, Suite 3500
Los Angeles
CA
90071-2411
US
|
Assignee: |
Medtronic MiniMed, Inc.
|
Family ID: |
27792162 |
Appl. No.: |
12/917162 |
Filed: |
November 1, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12121647 |
May 15, 2008 |
7833157 |
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12917162 |
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10331949 |
Dec 30, 2002 |
7500949 |
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12121647 |
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60414248 |
Sep 27, 2002 |
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Current U.S.
Class: |
600/309 ;
29/428 |
Current CPC
Class: |
A61B 5/415 20130101;
A61M 25/0032 20130101; A61M 25/0017 20130101; A61B 5/028 20130101;
A61B 5/1486 20130101; A61M 2025/0003 20130101; A61M 5/14244
20130101; A61B 5/14532 20130101; Y10T 29/49826 20150115; A61M
2230/201 20130101; A61M 25/0023 20130101; A61M 2025/0046 20130101;
A61M 5/1723 20130101 |
Class at
Publication: |
600/309 ;
29/428 |
International
Class: |
A61B 5/145 20060101
A61B005/145; B23P 17/04 20060101 B23P017/04 |
Claims
1.-38. (canceled)
39. A multilumen catheter comprising: a first tubing having a
length dimension and a plurality of lumens; the plurality of lumens
disposed within the first tubing and extending along the length
dimension of the first tubing, the plurality of lumens including a
sensor lumen and a first infusion lumen; a sensor lead extending
within the sensor lumen along the length dimension of the first
tubing to a sensor location; a sensor connected to the sensor lead
and arranged at the sensor location; the first infusion lumen
having an exit outlet on the first tubing at a location spaced
apart along the length dimension of the first tubing from the
sensor location.
40. A multilumen catheter of claim 39, wherein the sensor location
is within the sensor lumen of the first tubing.
41. A multilumen catheter of claim 39, wherein: the first tubing
has a distal end and a connection end; the sensor location is
closer to the distal end of the first tubing than the exit outlet
is to the distal end of the first tubing.
42. A multilumen catheter of claim 41, wherein the sensor lumen
terminates before the distal end of the first tubing.
43. A multilumen catheter of claim 41, further comprising a
junction element connected to the connection end of the first
tubing, the junction element connected to at least one second
tubing.
44. A multilumen catheter of claim 41, further comprising a
junction element connected to the connection end of the first
tubing, the junction element connected to a plurality of second
tubings.
45. A multilumen catheter of claim 44, wherein the plurality of
second tubings comprises a first infusion tubing and a second
infusion tubing.
46. A multilumen catheter of claim 45, wherein: the first tubing
includes a second infusion lumen; and the first infusion tubing
extends into the first infusion lumen and the second infusion
tubing extends into the second infusion lumen.
47. A multilumen catheter of claim 39, wherein: the first tubing
has a distal end and a connection end; the sensor location along
the length dimension of the first tubing, is between the exit
outlet and the distal end of the first tubing.
48. A multilumen catheter of claim 47, wherein the exit port is
closer to the connection end than the sensor location is to the
connection end.
49. A method of making a multilumen catheter, the method
comprising: forming a first tubing having a length dimension and a
plurality of lumens, the plurality of lumens disposed within the
first tubing and extending along the length dimension of the first
tubing, the plurality of lumens including a sensor lumen and a
first infusion lumen; extending a sensor lead within the sensor
lumen along the length dimension of the first tubing to a sensor
location; connecting a sensor to the sensor lead and arranging the
sensor at the sensor location; and forming an exit outlet of the
first infusion lumen in the first tubing at a location spaced apart
along the length dimension of the first tubing from the sensor
location.
50. A method of claim 49, wherein the sensor location is within the
sensor lumen of the first tubing.
51. A method of claim 49, wherein: the first tubing has a distal
end and a connection end; the sensor location is closer to the
distal end of the first tubing than the exit outlet is to the
distal end of the first tubing.
52. A method of claim 51, further comprising terminating the sensor
lumen before the distal end of the first tubing.
53. A method of claim 51, further comprising connecting a junction
element to the connection end of the first tubing, the junction
element connected to at least one second tubing.
54. A method of claim 51, further comprising connecting a junction
element to the connection end of the first tubing, the junction
element connected to a plurality of second tubings.
55. A method of claim 54, wherein the plurality of second tubings
comprises a first infusion tubing and a second infusion tubing.
56. A method of claim 55, wherein the first tubing includes a
second infusion lumen, the method further comprising: extending the
first infusion tubing into the first infusion lumen; and extending
the second infusion tubing extends into the second infusion
lumen.
57. A method of claim 49, wherein: the first tubing has a distal
end and a connection end; the sensor location along the length
dimension of the first tubing, is between the exit outlet and the
distal end of the first tubing.
58. A method of claim 57, wherein the exit port is closer to the
connection end than the sensor location is to the connection end.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Embodiments of the present invention relate to U.S.
Provisional Application, Ser. No. 60/414,248, filed Sep. 27, 2002,
entitled "Multilumen Catheter," which is incorporated by reference
herein and is a basis for a claim of priority, and to U.S.
Provisional Application, Ser. No. 60/390,940, filed Mar. 1, 2002,
entitled "System and Method of Monitoring Analyte Concentrations
Through a Central Line," which is also incorporated by reference
herein.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to the field of catheters and analyte
and therapy sensors used in biomedical applications and, in
particular, to a catheter having multiple lumens and a process of
making and using the same and to analyte and therapy sensors used
in critical care situations.
[0004] 2. Description of Related Art
[0005] The accurate and timely monitoring of vital signs and other
biomedical or physiological parameters in a critical care or
intensive care setting can often mean the difference between
success and disaster for patients and the medical care providers
rendering treatment for those patients. For such patients, the
quality of life and, possibly, even life itself may depend on such
monitoring.
[0006] Some types of physiological parameter monitoring, while
critical, have traditionally been slow and cumbersome. For example,
for patients who are in an intensive care environment, especially
those with diabetes, glucose monitoring is critical. If the amount
of glucose a patient's system is not maintained at proper levels,
the patient may sustain serious or life-threatening injury. If too
much glucose accumulates in the patient's system, the patient could
become hyperglycemic, resulting in shortness of breath, nausea and
vomiting at best or coma and death in the worst case. If there is
too little glucose in the patient's system, the patient could
become hypoglycemic, resulting in dizziness, sweating and headache
at best and unconsciousness and death in the worst case.
[0007] Glucose monitoring in a critical care or intensive care
environment has typically been done manually. For example, in some
facilities, if a patient with diabetes is in a critical or
intensive care environment, a medical care provider draws a sample
of blood from the patient and sends it to a lab, hopefully on site,
for glucose analysis. Based on the results of the analysis, the
patient is treated accordingly, possibly with insulin or glucose
infusion depending on whether the patient is hyperglycemic or
hypoglycemic, respectively. This process, i.e., drawing a sample of
blood from the patient, transferring the blood to a laboratory for
analysis, transferring the results of the analysis back to the
patient's medical care provider, reviewing the analysis,
recommending a suitable treatment, and administering the treatment,
can be cumbersome and is prone to human error.
[0008] Ideally, and for the benefit of the patient, the time
between admission of the patient to the critical or intensive care
ward to the time of drug infusion and stabilization of blood
glucose levels is minimal. However, given the nature of laboratory
diagnostics and manual analysis, the time lag from patient
admission to glucose analysis and, ultimately, to treatment is
sometimes longer than desirable.
[0009] In addition, for treatment to be rendered to the patient,
one or more catheters may be inserted into the patient's body. For
example, if treatment of the patient necessitates infusions of
blood and insulin, blood and drugs, blood and glucose or the like,
traditional caregivers have placed two separate catheters into the
patient's body and connected each catheter to an appropriate
infusion delivery system. For each catheter used, a separate
catheter tunneling procedure must be performed, which can be very
uncomfortable for the patient physically. Moreover, for each
catheter exiting the patient's body, the risk that a catheter is
disturbed, accidentally displaced or otherwise interfered with
increases. Also, multiple catheters can increase the risk of
infection.
[0010] Over the years, bodily characteristics have been determined
by obtaining a sample of bodily fluid. For example, diabetics often
test for blood glucose levels with a blood glucose meter.
Traditional blood glucose determinations have utilized a painful
finger prick using a lancet to withdraw a small blood sample that
is used by the blood glucose meter. However, in critical care
situations, these discrete blood meter readings are inefficient in
closely monitoring blood characteristics since they would need to
be taken every minute to provide near continuous data required
during critical care situations.
[0011] Long-term implanted sensors have been proposed that can stay
in the body for long periods of time, such as weeks and months.
These long-term implanted sensors are particularly well adapted in
delivering dependable data over a period of time as well as
detecting immediate changes in blood characteristics since they are
implanted in one of the main arteries near the heart. However,
these sensors need to be implanted in a separate procedure, often
not feasible for critical care patients. Moreover, although an
implanted sensor (e.g. a glucose sensor) may make sense for
diabetic patients needing long term care of the disease,
non-diabetic patients may not need a long-term implanted sensor
outside the intensive care unit.
SUMMARY
[0012] Accordingly, there is a need for a catheter having multiple
lumens that can deliver one or more infusants to a patient. There
is also a need for a catheter having one or more lumens for a
sensing element that can be located at an appropriate position in
the body of a patient to monitor vital signs and other biomedical
parameters. There is also a need for a catheter that can provide
signals for automatic analysis of vital physiological parameters
for monitoring the control and delivery of infusants to a
patient.
[0013] Embodiments of the present invention relate to a catheter
having one lumen or multiple lumens that can deliver one or more
infusants to a patient. Embodiments of the present invention
include a catheter having one or more lumens for a sensing element
that can be located at an appropriate position in the body of a
patient to monitor vital signs and other biomedical parameters.
Embodiments of the present invention include a catheter that can
provide signals for automatic analysis of vital physiological
parameters for monitoring the control and delivery of infusants to
a patient. Embodiments of the present invention also relate to an
improved method and system for detecting a blood characteristic of
a patient in an intensive care unit, which obviates for practical
purposes, the above-mentioned limitations.
[0014] A multilumen catheter according to an embodiment of the
present invention includes a first tubing, at least one lumen
disposed within the first tubing, a junction element and at least
one second tubing. The multilumen catheter may further include an
insertion piece that attaches to the at least one second tubing.
The at least one lumen may be extruded from the first tubing.
[0015] The first tubing may be coated with a lubricious coating
such as, for example, siloxane. The at least one second tubing may
include a first infusant tubing, a second infusant tubing and a
sensor tubing. Likewise, the at least one lumen may include a first
infusant lumen, a second infusant lumen and a sensor lumen. The
first infusant tubing may extend into the first infusant lumen, the
second infusant tubing may extend into the second infusant lumen
and the sensor tubing may extend into the sensor lumen. Also, the
at least one second tubing may extend into the at least one
lumen.
[0016] According to an embodiment of the present invention, the
first infusant lumen and the second infusant lumen exit the first
tubing at the same location. According to another embodiment of the
present invention, the first infusant lumen and the second infusant
lumen exit the first tubing at different locations. Also, a sensor
lead, which may have a sensing element, may extend through the
sensor tubing and the sensor lumen. The sensing element may be
positioned distal to the first tubing or may be positioned proximal
to the first tubing.
[0017] According to an embodiment of the present invention,
infusion members may be connected to the first and second tubings.
The infusion members may include fittings, such as, for example,
injection sites, caps and clamps.
[0018] A method for using a multilumen catheter according to an
embodiment of the present invention may include inserting a distal
end of the multilumen catheter into a patient, affixing an
external, proximal end of the multilumen catheter to the patient,
and affixing infusion members to the external, proximal end of the
multilumen catheter. The method may also include affixing
electronic elements to the external, proximal end of the multilumen
catheter.
[0019] According to an embodiment of the present invention, a
multilumen catheter may include, a first lumen having a contour and
a plurality of second lumens having contours complementary to the
first lumen, wherein the contour of the first lumen and the
contours of the plurality of second lumens maximize an inner volume
of the first lumen and an inner volume of the plurality of the
second lumens and minimize an outer dimension of the first lumen
and an outer dimension of the plurality of the second lumens. One
of the plurality of second lumens may be shaped to provide a path
for a guide wire. The first lumen may be used for a sensor lead and
at least one of the plurality of second lumens is used for drug
delivery and/or blood product infusion.
[0020] The multilumen catheter may also include a first tubing
connected to the first lumen, a plurality of second tubings
connected to the plurality of second lumens, infusion sources
connected to the plurality of second tubings, and a containment
clement surrounding the first tubing and the plurality of second
tubings for maintaining the position of the first tubing and the
plurality of second tubings.
[0021] According to an embodiment of the invention, a central line
catheter for delivering fluids directly into a main artery or vein
near the heart contains a first lumen to deliver a fluid through
the central line catheter and a second lumen containing a sensor
capable of indicating a characteristic level in blood, wherein the
first lumen delivers the fluid downstream of the sensor to prevent
any interference between the fluid delivery and the sensor
readings. The first lumen may also deliver fluid upstream of the
sensor. In addition, the central line catheter can have additional
lumens for additional purposes. In particular embodiments, the
central line catheter further includes a flush sleeve to remove
debris, such as, for example, biological debris, around the sensor.
In still other embodiments, the sensor is an analyte or therapy
sensor, such as, for example, a glucose analyte sensor.
[0022] According to another embodiment of the invention, a system
for delivering and monitoring a condition in an intensive care unit
is provided. The system contains a central line catheter comprising
a first lumen to deliver fluid and a second lumen containing a
sensor capable of indicating a characteristic level in blood; an
infusion device for delivering fluid through the first lumen; and a
monitoring device for displaying readings obtained by the
sensor.
[0023] Other features and advantages of the invention will become
apparent from the following detailed description, taken in
conjunction with the accompanying drawings, which illustrate, by
way of example, various features of embodiments of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 shows a plan view of a generalized multilumen
catheter according to an embodiment of the present invention.
[0025] FIG. 2 shows an internal portion of a lumen tubing according
to an embodiment of the present invention.
[0026] FIG. 3 shows a plan view of details of a junction element
according to an embodiment of the present invention.
[0027] FIG. 4 shows a plan view of details of the union between the
junction element and the lumen tubing according to an embodiment of
the present invention.
[0028] FIG. 5 shows a perspective view of an infusion member
according to an embodiment of the present invention.
[0029] FIG. 6 shows a method for assembling an infusion member
according to an embodiment of the present invention.
[0030] FIG. 7 shows a multilumen catheter assembly according to an
embodiment of the present invention.
[0031] FIG. 8a shows a plan view of markings on a sensor lead
according to an embodiment of the present invention.
[0032] FIG. 8b shows a plan view of markings on infusion members
according to an embodiment of the present invention
[0033] FIG. 9 shows a multilumen catheter implanted into a patient
according to an embodiment of the present invention.
[0034] FIG. 11 is a schematic diagram illustrating a central line
with an analyte sensor in accordance with the embodiments of the
present invention.
[0035] FIG. 12 is a graph of a study performed using the central
line with an analyte sensor in accordance with the embodiments of
the present invention.
[0036] FIG. 13 illustrates an alternative embodiment of the central
line catheter in accordance with the embodiments of the present
invention.
[0037] FIG. 14 illustrates another alternative embodiment of the
central line catheter in accordance with the embodiments of the
present invention.
[0038] FIG. 15 is a cross-sectional view of the central line along
line #1 of FIG. 10, in accordance with the embodiments of the
present invention.
[0039] FIG. 16 is a cross-sectional view of the central line along
line #2 of FIG. 10, in accordance with the embodiments of the
present invention.
DETAILED DESCRIPTION
[0040] In the following description of preferred embodiments,
reference is made to the accompanying drawings which form a part
hereof, and in which are shown by way of illustration specific
embodiments in which the invention may be practiced. It is to be
understood that other embodiments may be utilized and structural
changes may be made without departing from the scope of the present
invention.
[0041] A generalized multilumen catheter 10 according to an
embodiment of the present invention is shown in FIG. 1. The
multilumen catheter 10 includes, without limitation, a lumen tubing
12 having lumens within its interior, a junction element 14, a
first infusion tubing 16 connected to one of the lumens within the
interior of the lumen tubing 12, a second infusion tubing 18
connected to one of the lumens within the interior of the lumen
tubing 12, a sensor tubing 20 connected to one of the lumens within
the interior of the lumen tubing 12, a sensor lead 22 and infusion
members 26. A distal end of the sensor lead 22 also includes a
sensing element 24.
[0042] In one example embodiment, the lumen tubing 12 may be
inserted into a patient percutaneously such that the sensing
element 24 is located at a desired in vivo location. A sensing
element suitable for this type of embodiment is disclosed in a
patent application entitled "Sensing Apparatus and Process," Ser.
No. 10/036,093, filed Dec. 28, 2001, which is hereby incorporated
by reference, and in a patent application entitled "Sensor
Substrate and Method of Fabricating Same," Ser. No. 10/038,276,
filed Dec. 31, 2001, which is also hereby incorporated by
reference. In another example embodiment, the multilumen catheter
10 may be fully implanted into the body of a patient.
[0043] The junction element 14, the first infusion tubing 16, the
second infusion tubing 18, the sensor tubing 20 and the infusion
members 26 are located external to the patient. Thus, the infusion
members 26 may be connected to infusion delivery systems such that
blood products, medicines and other infusants may be delivered to
the patient through the various tubings. The external portion of
the sensor lead 22 may be connected to data acquisition equipment,
monitoring equipment, or other electronic devices to provide
feedback, to control the delivery of infusants, to provide other
control functions and the like.
[0044] The overall length of the multilumen catheter 10 may vary
according to the size of the patient. For example, according to an
embodiment of the present invention, the overall length of the
lumen tubing 12 may be any suitable length from about 9 to 14
inches measured from a point on the first infusion tubing 16 or the
second infusion tubing 18 where infusants enter the tubings to the
distal end of the lumen tubing 12 where the first infusion tubing
16, the second infusion tubing 18 and the sensor tubing 20
terminate. The sensor lead 22, according to an embodiment of the
present invention, may be any suitable length from about 12 to 16
inches in length. The sensor lead 22 may be positioned such that
the sensing element 24 is located distal to the end of the lumen
tubing 12. According to another embodiment of the present
invention, the sensor lead 22 may be positioned such that the
sensing element 24 is located at the end of the lumen tubing
12.
[0045] Also, according to one embodiment of the present invention,
the outer diameter of the lumen tubing 12 is less than 0.120
inches. Maintaining the outer diameter of the lumen tubing 12 at
less than 0.120 inches may facilitate insertion of the lumen tubing
12 into a patient. According to another embodiment of the present
invention, the outer diameter of the lumen tubing 12 is less than
0.140 inches. According to yet another embodiment of the present
invention, the outer diameter of the lumen tubing 12 is about 0.130
inches.
[0046] An internal portion of the lumen tubing 12 according to an
embodiment of the present invention is shown in FIG. 2. In FIG. 2,
three lumens, a sensor lumen 30, a drug lumen 32 and a blood lumen
34 are formed within the interior of the lumen tubing 12. As can be
seen, the lumens form isolated paths within the lumen tubing
12.
[0047] The lumens may be formed within the interior of the lumen
tubing 12 by a variety of methods. For example, in the embodiment
shown, the sensor lumen 30, the drug lumen 32 and the blood lumen
34 have been extruded out of silicone. However, any method of lumen
tubing formation that is suitable in the industry may be used
depending on the application and environment for the catheter,
including, but not limited to, extrusion, molding, machining or
combinations thereof. In addition, materials other than silicone
may be used for the catheter, including, but not limited to,
polyurethane, polyethylene, Teflon, PVC, Elastomeric, hydrogel and
the like.
[0048] For example, if a Swan-Ganz catheter, which typically has
five lumens, all with a special purpose, were adapted for use with
embodiments of the present invention, it could be modified by
adding an additional lumen to provide a location for a sensor.
Thus, a Swan-Ganz catheter could be fabricated with six lumens to
accommodate a sensor. Also, the size of the sensor may be modified
to accommodate the size of the lumen.
[0049] Embodiments of the present invention may also be adapted for
use with Peripherally Inserted Central Catheter (PICC) lines. A
PICC line could be fabricated similar to a central line catheter,
but, according to embodiments of the present invention, could be
smaller and longer.
[0050] Embodiments of the present invention may also be adapted for
use with double lumen central line catheters. For example, in
adapting embodiments of the present invention to a double lumen
central line catheter, the catheter may include one lumen for an
infusant and one lumen for a sensor.
[0051] The lumens formed within the interior of the lumen tubing 12
may be formed into a variety of sizes and shapes. For example, as
can be seen in FIG. 2, the sensor lumen 30 has been extruded such
that its horizontal dimension is slightly longer than its vertical
dimension, i.e., it is somewhat oval in shape. The sensor lumen 30,
according to this embodiment, has been formed in this way due to
the nature of the sensor lead 22 that will be placed into it.
[0052] For example, because there may be loose pieces in the sensor
lead 22, the sensor lumen 30 may be formed such that it provides a
compression fit for the sensor lead 22. Thus, the oval shape of the
sensor lumen 30 was chosen for this particular embodiment. An oval
shape facilitates compression as follows: in the horizontal
direction, the lumen is the same size as the horizontal direction
of the sensor (there are no "loose parts" in this direction); in
the vertical direction (the direction on the sensor which has
assembled loose parts), the lumen is undersized so that the sensor
is "squeezed" into placed. However, other shapes may be chosen for
the sensor lumen 30 or any of the other lumens that may exist
within the interior of the lumen tubing 12 depending on the
application.
[0053] The drug lumen 32 and the blood lumen 34 have also been
shaped to facilitate the nature of their uses. For example, because
both the drug lumen 32 and the blood lumen 34 reside alongside the
sensor lumen 30, which has been formed in a quasi-oval shape, a
portion of one side of each of the drug lumen 32 and the blood
lumen 34 has been formed to also be somewhat oval in shape such
that the curved portions of the drug lumen 32 and the blood lumen
34 follow the contour of the sensor lumen 30. This allows for
maximizing lumen cross-section area (or volume), while minimizing
overall outer diameter of the catheter. The blood lumen 34 may be
configured to maximize volume within the dimensions of the lumen
tubing because, for some applications, it is necessary that the
blood lumen 34 be directed around a guide wire. Because of the
flexible nature of the catheter, it is sometimes difficult to
maneuver the catheter through the body of a patient. In practice,
it is sometimes desirable to first insert a rigid guide wire into
the patient and then maneuver the catheter into the patient by
directing it about the guide wire such that the guide wire is
eventually positioned inside a lumen. Once the catheter is in the
desired location, the guide wire may be removed, leaving the
catheter in the proper position.
[0054] In addition, the blood lumen 34, according to the embodiment
shown in FIG. 2, is configured with minimal sharp corners, or
"stagnant zones," as possible. A "stagnant zone" is a portion of
the lumen where blood may clot. Because blood clotting is generally
an undesirable effect, the blood lumen 34 has been configured to
minimize sharp corners so as to prevent blood clotting.
[0055] The physical locations of the lumens within the interior of
the lumen tubing 12 depend on a variety of factors. For example, as
was mentioned above, in the embodiment shown in FIG. 2, the
location of the drug lumen 32 and the blood lumen 34 is dictated,
in part, due to the location and shape of the sensor lumen 30. In
addition, in the embodiment shown in FIG. 2, the drug lumen 32 and
the blood lumen 34 has been positioned such that a strut 36 is
formed between them. The strut 36 may provide additional strength
for the sensor lumen 30, which may be advantageous if, for example,
the distal end of the sensor lead 22 (where the sensing element 24
is located) docs not extend past the end of the lumen tubing 12.
Generally, the lumens that are formed within the lumen tubing 12
may be formed such that they generate structural elements within
the interior of the lumen tubing 12 from the material used for the
interior of the lumen tubing 12.
[0056] Also, the drug lumen 32 and the blood lumen 34 may be formed
such that they exit the lumen tubing 12 at the same site, for
example, to facilitate manufacturing of the multilumen catheter.
However, the drug lumen 32 and the blood lumen 34 need not exit at
the same site and, instead, may exit at different sites depending
on the application of the multilumen catheter. Although sensor
reading interference may be prevented by having a "downstream" exit
site, it is possible to have an "upstream" exit site without any
corruption of sensor information. For example, if a Swan-Ganz
catheter is adapted to embodiments of the present invention, the
Swan-Ganz catheter may be used to measure cardiac output using a
cold-fluid dilution technique in which a bolus of a cold solution
is infused at a known temperature. The temperature may then be
measured at a known point downstream. The temperature difference is
based on the volume of fluid passing from the initial infusion
point to the temperature measurement point based on time.
[0057] Lumens may be formed to exit at different sites in a variety
of ways. For example, staggered exit sites may be formed by: 1)
forming a back-filled tip of one lumen with stamped side ports; 2)
terminating one lumen "early" by trimming the tubing or molding a
shortened lumen; or 3) forming an adhered "nose cone" that directs
fluid (either through a side exit site, or a shortened lumen.
[0058] The sensor lead 22 and the sensing element 24 may also be
placed in a variety of locations in relation to the lumen tubing
12. For example, the sensor lead 22 may be placed proximal to the
lumen tubing 12 such that the sensing element 24 rests at one end
of the lumen tubing 12. If this location is chosen for the sensing
element 24, according to one embodiment of the present invention,
it may be advantageous to provide tubing at the end of the lumen
tubing 12 that is radio-opaque to x-rays so that the position of
the catheter tip may be identified under x-ray. If the sensing
element 24 is positioned distal to the lumen tubing 12, it will
itself be visible under x-ray and its position may easily be
determined under x-ray.
[0059] Details of a junction element 14 according to an embodiment
of the present invention may be seen in FIG. 3. The junction
element 14 in FIG. 3 comprises a first junction element end 40, a
second junction element end 42 and suture tabs 44. In the
embodiment shown in FIG. 3, the first junction element end 40 is
arc-shaped and large enough so that it may accommodate various
tubings and fittings. The second junction element end 42 is much
narrower than the first junction element end 40 and is formed large
enough so that it can accommodate the two infusion line tubings and
the sensor tubing used in the shown embodiment. However, both the
first junction element end 40 and the second junction element end
42 may be formed into a variety of shapes and sizes, dictated by
the nature of the environment in which the catheter is used.
[0060] The suture tabs 44 may be used by a medical care provider to
suture the junction element 14 onto the patient or to attach to
some other surface. In this way, the risk that the catheter moves
while in use is minimized. In addition to or alternative to the
suture tabs 44, other means may be employed to fix the junction
element 14 to the patient or other surface. For example, the
junction element 14 may be formed with another type of tab or any
other element that would facilitate immobilizing the catheter to
the patient. For example, the suture tabs 44 could be adhesive
rather than mechanical sewing. In addition, other shapes would also
suffice as long as the risk of the suture shearing thorough the
tags is minimized.
[0061] The junction element 14 may be made from a variety of
materials. For example, according to one embodiment of the present
invention, the junction element 14 is formed from liquid silicone
rubber. However, a variety of plastics and other materials may be
used. In addition, the junction element 14 is not limited to the
shape shown in FIG. 3. The junction element 14 may be formed into
any shape that facilitates its application.
[0062] FIG. 4 shows details of the union between the junction
element 14 and the lumen tubing 12. The junction element 14 may be
affixed to the lumen tubing 12 by a variety of methods. For
example, according to an embodiment of the present invention, the
lumen tubing 12 may be joined to the junction element 14 by a
compression fit. According to another embodiment of the present
invention, the junction element 14 may be bonded to the lumen
tubing 12 using an adhesive. Suitable adhesives may include, but
are not limited to, medical grade silicone adhesives or other
medical grade adhesives. Depending on the materials used to
fabricate the junction element 14 and the lumen tubing 12, a primer
may be needed to facilitate an adhesive bond between the junction
element 14 and the lumen tubing 12. Suitable primers may include,
but are not limited to, adhesives diluted with heptane or other
solvents.
[0063] Positioned within the junction element 14 are the first
infusion tubing 16, the second infusion tubing 18 and the sensor
line 20. The first infusion tubing 16, the second infusion tubing
18 and the sensor line 20 extend from their associated lumens
within the lumen tubing 12 to the expanded portion of the junction
element 14. According to one embodiment of the present invention,
the tubings may adhesively attach to their associated lumens.
According to another embodiment of the present invention, the
tubings may be molded into place. At the expanded end of the
junction element 14, the first infusion tubing 16 and the second
infusion tubing 18 are fitted with infusion tubing core pins 50
while the sensor tubing 20 is fitted with a sensor tubing core pin
52. The infusion tubing core pins 50 and the sensor tubing core pin
52 maintain the shape and position of the first infusion tubing 16,
the second infusion tubing 18 and the sensor tubing 20 as they
extend through the junction element 14 into their associated lumens
within the interior of the lumen tubing 12. In addition, the
infusion tubing core pins 50 and the sensor tubing core pin 52
provide a larger surface with which to attach infusion lines and a
sensor lead, respectively. The infusion tubing core pins 50 and the
sensor tubing core pin 52 may be made from a variety of materials,
including, but not limited to, stainless steel, titanium, delrin,
TEFLON, or any metal or non-porous plastic. Whatever the material
used, it should have a high melt point for hot transfers or a low
melt point for cold molds
[0064] An infusion member 26 according to an embodiment of the
present invention is shown in FIG. 5. The example infusion member
26 includes an infusion member lead tubing 60, a strain relief
tubing 62, a female Luer fitting 64, a male Luer cap 66, and a male
Luer injunction site 68. A tubing clamp 69 may also be used in
connection with the infusion member 26. Any suitable tubing clamp
structure may be used, including but not limited to, a spring
action clamp 69 as shown in FIG. 5, a pinch clamp, slide clamp,
roller clamp or the like.
[0065] The infusion member lead tubing 60 may comprise a silicone
tubing and is generally inserted into a core pin. The strain relief
tubing 62 provides support for the junction between the infusion
member lead tubing 60 and the female Luer fitting 64 by stretching
over the top of the infusion member lead tubing 60 and securing
itself and the infusion member lead tubing 60 to the Luer fitting
64. Any materials suitable for the catheter would also be suitable
for the strain relief tubing 62. Should it become necessary to
restrict the flow of infusant travelling through the infusion
member 2, the tubing clamp 69 may be positioned onto a deformable
location of the infusion member 26, or the strain relief tubing 62,
to clamp off the infusion member 26 and restrict the flow of
infusant through the infusion member 26. The strain relief tubing
62 also holds the tubing clamp 69 so that the inner (and thinner)
infusion member lead tubing 60 will not permanently deform if the
clamp is secured for a long time. Moreover, by holding the tubing
clamp 69, the infusion member lead tubing 60 may be less
susceptible to fatigue stresses (e.g., from opening and closing the
tubing clamp 69 repeatedly, movement of the infusion tubes or
pulling on the infusion tubes during IV infusion) and accidental
dislodgment of the tube from the fitting.
[0066] The male Luer cap 66 may be inserted into the female Luer
fitting 64 when the infusion member 26 is not in use. When it
becomes necessary to inject an infusant into the patient, the male
Luer injection site 68 may be used in place of the male Luer caps
66. Although Luer fittings are used in the embodiment shown in FIG.
5, any type of fitting, such as a locking fitting, for example,
that is appropriate for the application may be used in combination
with the infusion member 26. Also, the male Luer caps 66 may have
latex or non-latex septum or injection sites that may be used to
receive needles or an IV drip system. Also, the male and female
fittings may be reversed from the arrangement shown in FIG. 5.
[0067] The infusion members 26 and all associated caps, fittings,
locks and the like may be color coded for easy identification. For
example, an infusion member 26 used for blood may be color coded
red while an infusion member 26 used for drugs, glucose or other
medicants may be color coded white.
[0068] A method for assembling the infusion member 26 according to
an embodiment of the present invention is shown in FIG. 6. At step
70, the strain relief tubing 62 is placed over the infusion member
lead tubing 60. To facilitate this step, the hollow portion of the
strain relief tubing 62 should be large enough to accommodate the
diameter of the infusion member lead tubing 60, but not so large
that it is ineffective to provide the desired strain relief. At
step 72, the female Luer fitting 64 is inserted into the infusion
member lead tubing 60. The position of the female Luer fitting 64
may be maintained by compression and the friction between the
female Luer fitting 64 and the infusion member lead tubing 60.
[0069] Once the female Luer fitting 64 has been inserted into the
infusion member lead tubing 60, the strain relief tubing 62 is then
slid back toward the female Luer fitting 64 at step 74 so that it
completely covers that portion of the female Luer fitting 64 that
has been inserted into the infusion member lead tubing 60. Using
the method shown in FIG. 6, the infusion member 26 may be assembled
quickly and without adhesives. However, in other embodiments,
adhesives may be used assemble the infusion member 26. In yet other
embodiments, the catheter could be completely molded, i.e., plastic
fittings could molded into the infusion line/junction/distal tube
mold, or the fittings could be molded into the full part mold.
[0070] An assembled multilumen catheter assembly according to an
embodiment of the present invention is shown in FIG. 7. Male Luer
caps 66 have been inserted into female Luer fittings 64, which in
turn have been inserted into infusion member lead tubings 60.
Strain relief tubings 62 cover the junction between the female Luer
fitting 64 and the infusion member lead tubing 60. The infusion
member lead tubings 60 have been inserted into infusion tubing core
pins 50 residing within the junction element 14. The infusion
tubing core pins 50 may be affixed to the first infusion tubing 16
and the second infusion tubing 18. The sensor tubing core pin 52,
also residing within the junction element 14, is affixed to the
sensor tubing 20. The first infusion tubing 16, the second infusion
tubing 18 and the sensor line 20 extend through the junction
element 14 into the first infusion lumen 32, the second infusion
lumen 34 and the sensor lumen 30, respectively. Within the junction
element 14, the first infusion tubing 16, the second infusion
tubing 18 and the sensor tubing 20 may be bonded in place with an
adhesive or otherwise maintained in their relative positions.
[0071] The junction element 14 may be bonded to or otherwise
affixed to the lumen tubing 12. For example, according to an
embodiment of the present invention, the lumen tubing 12 may be
molded into the junction element 14 with an angle on the core pins
that stretch the lumen tubing 12 open within the mold to create a
mechanical interference fit that cannot be easily pulled apart. The
junction element 14 is also configured with suture tabs 44. Thus,
the embodiment of the present invention shown in FIG. 7, once it
has been equipped with a sensor lead having a sensing element, is
ready for use. The lumen tubing 12 may be inserted into a patient,
the suture tabs may be sutured to the patient and the Luer fittings
may be affixed to drug and blood infusion lines for delivery of
infusant to the patient. When the sensor lead 22 is connected to
its associated electronics, the delivery of infusant to the patient
may be automatically monitored and controlled.
[0072] FIG. 8a shows how a sensor lead 20 may be marked according
to an embodiment of the present invention. A sensor scale 82 may be
provided on the sensor as shown in FIG. 8a. Although the sensor
scale 82 would typically be marked in elements of length such as
centimeters, for example, the sensor scale 82 may be marked with
any units desired for a particular application. The sensor scale 82
may be marked with ink or other permanent marking. Thus, if the
lumen tubing 12 is made from a transparent or partially transparent
material such as silicone, for example, the sensor scale 82 that
has been inked onto the sensor line 20 may be seen directly through
the lumen tubing 12. According to another embodiment of the present
invention, an opaque tube with marking on the outside or makings
that have been molded into an opaque part with later inking for
greater definition may also be used.
[0073] Infusion members 26 may also be identified as shown in FIG.
8b according to an embodiment of the present invention. For
example, infusion member lead tubings may be identified with lead
tubing identifications 84. In the embodiment shown in FIG. 8, the
lead tubing identifications 84 designate the actual gauge of the
associated lumen, in this case, for example, 18-gauge. Also, the
strain relief tubings 64 may be identified with clamping site
identifications 86. Clamping site identifications 86 provide a
visual indication for the site at which the tubing clamp 69 may be
manually located.
[0074] FIG. 9 shows the multilumen catheter 10 as it exists
implanted into a patient according to an embodiment of the present
invention. Insertion of the multilumen catheter 10 into the body
may be accomplished via a subclavian vein, an internal jugular vein
or other suitable manners. In the embodiment shown in FIG. 9, the
entrance is through a subclavian vein. Thus, the multilumen
catheter 10 is inserted at a percutaneous site 90 and routed
underneath a clavicle 92. The multilumen catheter 10 is extended
through the subclavian vein until the sensor tip 24 resides at a
position desired by the physician, which will be dictated in part
by the size and body characteristics of the patient 91. The
junction element 14 rests in the general vicinity of the shoulder
of the patient 91. Luer fitted infusion ports 93 and a sensor
extension line connector 95 are external to the patient and may be
connected to infusion lines and sensor electronics 94,
respectively. The sensor extension line 94 may be connected to a
percutaneous monitor 96, such as, for example, an in vivo glucose
monitor or a personal pump communicator. The percutaneous monitor
96 may be affixed to the patient, such as, for example, by using an
elastic armband 98.
[0075] According to the embodiment shown in FIG. 9, if a diabetic
patient, for example, is in an intensive care or other critical
care or medical care situation, the patient may be fitted with the
multilumen catheter 10 for automatic monitoring of control and
delivery of one or more infusants to the patient. For example, the
multilumen catheter 10 may be inserted percutaneously into the
patient through a subclavian vein. The sensor lead 22 may be
directed to a desired location in the body, such as, the right
atrial junction. In this manner, the sensing element 24 may rest at
a location suitable for parameter monitoring, such as, glucose
monitoring. The sensing element 24 may extend several inches past
the end of the lumen tubing 12 or may extend to the end of the
lumen tubing 12. Thus, even though the sensor lead 22 may be
positioned in vivo, a medical care provider may determine how far
into the body the sensor lead has extended by observing the
markings on the sensor lead 22 that are external to the body in the
vicinity of the junction element 14.
[0076] The junction element 14, which is external to the patient,
may be sutured to the patient in the general vicinity of the
shoulder area using the suture tabs 44. Infusant delivery systems
may be connected to the infusion members 26 while the external
portion of the sensor lead 22 may be connected to electronics. Once
powered by the electronics, the sensing element 24 can sense
glucose or other parameters, which are read by the electronics. The
electronics in turn may control the infusant delivery systems to
deliver infusants, such as, for example, blood, glucose, other
medicants and the like to the infusion members 26. The infusant
will travel through the infusion members 26 to the infusion lumens
32, 34 and exit the catheter at the end of the lumen tubing 12
where the lumens 32, 34 terminate, thus delivering the required
treatment to the patient.
[0077] Embodiments of the present invention may be used
percutaneously or may be implanted. For example, the multilumen
catheter 10 may be used percutaneously or may be fully
implanted.
[0078] A combined insulin delivery catheter and sensor for
peritoneal applications according to an embodiment of the present
invention is shown in FIG. 10. The embodiment of the invention sown
in FIG. 10 includes, without limitation, a sensor 120, which may be
a glucose sensor, a delivery catheter 122, which may be an insulin
delivery catheter, a pump 124, which may be an insulin pump, and a
combined sensor and catheter header 126.
[0079] In the embodiment of the invention shown in FIG. 10, the
glucose sensor 120 and the insulin delivery catheter 122 may be
used percutaneously or may be implanted. If the insulin pump 124
and the sensor and catheter header 126 are designed to be
implanted, the entire embodiment of the invention shown in FIG. 10
may be implanted into a patient. If the insulin pump 124 and the
sensor and catheter header 126 are not designed to be implanted,
the combined insulin delivery catheter 122 and glucose sensor 120
may be inserted percutaneously into the body and may extend out of
the body and attach to the sensor and catheter header 126 and the
insulin pump 124. Also, the embodiment of the invention shown in
FIG. 10 may be used for peritoneal applications.
[0080] Embodiments of the present invention may also be directed to
a single lumen catheter. For example, embodiments of the present
invention may include a single lumen device having no other lumens
that is used as a percutaneous device. The single lumen may be used
for a sensor or for an infusant. For example, according to an
embodiment of the present invention, a single lumen catheter may
include a sensor used a percutaneous device. Thus, a sensor may be
inserted into the body and still extend outside of the body for
connection to monitoring or control electronics or other devices.
The sensor may be included in a sleeve or may be inserted with a
sleeve that is later removed. The sensor may remain in the body for
a period of time.
[0081] In a single lumen catheter according to embodiments of the
present invention, the single lumen catheter may include elements
described above in connection with a multilumen catheter. For
example, the single lumen catheter may include a lumen tubing
having a lumen within its interior, a junction element, a sensor
tubing connected to the lumen within the interior of the lumen
tubing, and a sensor lead. A distal end of the sensor lead may also
include a sensing element. The single lumen catheter may also
include Luer fittings and Luer caps.
[0082] Embodiments of the present invention may be directed to an
improved central line catheter with a built in analyte and/or
therapy sensor that determines body characteristics on a
continuous, intermittent or near continuous basis. In addition to
an improved central line catheter, embodiments of the invention may
also be directed to an improved Swan-Ganz catheter or PICC line.
FIG. 11 is a schematic diagram illustrating the central line
catheter 100 with an analyte sensor 114 in accordance with the
preferred embodiments of the present invention. Central line
catheters are known in the art and typically used in the Intensive
Care Unit (ICU)/Emergency Room of a hospital to deliver medications
through one or more lumens of the catheter to the patient
(different lumens for different medications). The central line
catheter 100 is typically connected to an infusion device (e.g.
infusion pump, IV drip, or syringe port) on one end and the other
end inserted in one of the main arteries or veins near the
patient's heart to deliver the medications. The infusion device
(not shown) delivers medications, such as, but not limited to,
saline, drugs, vitamins, medication, proteins, peptides, insulin,
neural transmitters, or the like, as needed to the patient. In
alternative embodiments, the central line catheter can be used in
any body space or vessel such as intraperitoneal areas, lymph
glands, the subcutaneous, the lungs, the digestive tract, or the
like and may determine the analyte or therapy in body fluids other
than blood.
[0083] The central line catheter 100 of FIG. 11 is shown as a
double lumen catheter. In preferred embodiments of the present
invention, the analyte sensor 114 is built into one lumen 110 of
the central line catheter 100 and is used for determining
characteristic levels in the blood and/or bodily fluids of the
user. In the preferred embodiment, the analyte sensor 114 is a
glucose sensor as generally described in U.S. Pat. Nos. 4,650,547;
4,671,288; 4,781,798; 4,703,756; and 4,890,620, which are
incorporated by reference herein. However, it will be recognized
that further embodiments of the invention may be used to determine
the levels of other agents, characteristics or compositions, such
as hormones, cholesterol, medications, concentrations, viral loads
(e.g., HIV), or the like. Therefore, although embodiments of the
present invention are primarily described in the context of glucose
sensors used in the treatment of diabetes/diabetic symptoms, the
embodiments of the invention are applicable to a wide variety of
patient treatment programs where a physiological characteristic is
monitored in an ICU.
[0084] As shown in FIG. 11, the sensor 114 is located in a first
lumen 110 of the central line catheter 100. An orifice 112 exists
in the first lumen 110 to allow blood to contact the sensor 114,
and for the sensor 114 to collect data. The sensor 114 then sends
the information through the sensor connector 102 to a monitor
system (not shown), where the data can be processed and displayed.
The monitor system presents the blood characteristic in real-time
or near real-time format to allow for immediate monitoring of the
patient's condition. The glucose sensor 114 generally includes, in
one preferred form, an improved implantable enzyme electrode of the
general type described in U.S. Pat. Nos. 4,650,547; 4,671,288;
4,781,798; 4,703,756; and 4,890,620, and more recently described in
U.S. patent application Ser. No. 10/038,276, filed on Dec. 31,
2001, entitled "Sensor Substrate and Method of Fabricating the
Same," U.S. patent application Ser. No. 10/036,093, filed on Dec.
28, 2001, entitled "Sensing Apparatus and Process," and U.S. patent
application Ser. No. 10/034,338, filed on Dec. 28, 2001, entitled
"Implantable Sensor Electrodes and Electronic Circuitry" which are
incorporated by reference herein. Such enzyme electrodes include a
sensor tip for direct contact with patient fluids, such as blood.
The sensor tip defines a conductivity sensor for measuring fluid
conductivity changes in response to an enzymatic reaction typically
involving the use of glucose oxidase to catalyze glucose in the
presence of oxygen (O.sub.2). Conductivity signals are transmitted
through the sensor 114 via conductors to a proximal end of the
sensor 104 to the monitor system via the sensor connector 102.
[0085] In alternative embodiments, different sensor technology may
be used, such as, but not limited to an optical sensor. Preferably,
an the implantable optical sensor would include a photo-reactive
substance or compound that optically changes, fluoresces, or the
like, or other suitable compounds that detect changing properties
in the presence of a bodily fluid analyte, such as glucose or the
like. The compounds can also be used to detect the level of an
analyte that has been ingested, injected or placed inside the body,
such as marker substances, or the like. For example, possible
compounds, including but not limited to, produce a fluorescent
change in the presence of a bodily fluid analyte are disclosed in
U.S. Pat. No. 5,503,770 issued Apr. 2, 1996 to James et al. and
entitled "Fluorescent Compound Suitable For Use In The Detection Of
Saccharides"; U.S. Pat. No. 5,512,246 issued Apr. 30, 1996 to
Russell et al. and entitled "Method and Means for Detecting
Polyhydroxyl Compounds"; U.S. Provisional Application Ser. No.
60/007,515 to Van Antwerp et al. and entitled "Minimally Invasive
Chemically Amplified Optical Glucose Sensor"; and U.S. Pat. No.
6,011,984 to Van Antwerp et al. and entitled "Detection of
Biological Molecules Using Chemical Amplification", all of which
are herein incorporated by reference. Other compounds using Donor
Acceptor fluorescent techniques may be used, such as disclosed in
U.S. Pat. No. 5,628,310 issued May 13, 1997 to Rao et al. and
entitled "Method and Apparatus to Perform Trans-cutaneous Analyte
Monitoring"; U.S. Pat. No. 5,342,789 issued Aug. 30, 1994 to Chick
et al. and entitled "Method and Device for Detecting and
Quantifying Glucose in body Fluids"; and U.S. Pat. No. 5,246,867
issued Sep. 21, 1993 to Lakowicz et al. and entitled "Determination
and Quantification of Saccharides by Luminescent Lifetimes and
Energy Transfer", all of which are herein incorporated by
reference.
[0086] In the preferred embodiments where the sensor is a glucose
sensor and characteristic to be determined is a blood glucose
level, the glucose monitor is generally of the type described in
U.S. patent application Ser. No. 09/511,580, filed on Feb. 23,
2000, entitled "Glucose Monitor Calibration Methods", which is
herein incorporated by reference. In alternative embodiments, the
glucose monitor is generally of the type described in U.S. patent
application Ser. No. 09/377,472, filed Aug. 19, 1999, entitled
"Telemetered Characteristic Monitor System And Method Of Using The
Same", which is incorporated by reference herein.
[0087] In preferred embodiments, the monitor system contains both a
monitor, which attaches to the sensor 114 and records the raw
sensor data; and a data processor (not shown), which contains the
software and programming instructions to download and evaluate data
recorded by the monitor. However, in alternative embodiments, the
monitoring process electronics can be built into separate devices.
In addition, although the monitor system takes raw sensor data from
the sensor 114 and assesses it during real-time in preferred
embodiments, the monitor system can also store the raw data for
later processing or downloading to the data processor. In
alternative embodiments, the monitoring system may include a
display that is used to display the calculated results of the raw
glucose sensor data received via a download from the glucose
monitor. The results and information displayed includes, but is not
limited to, trending information of the characteristic (e.g., rate
of change of glucose), graphs of historical data, average
characteristic levels (e.g., glucose), stabilization and
calibration information, raw data, tables (showing raw data
correlated with the date, time, sample number, corresponding blood
glucose level, alarm messages, and more), and the like.
[0088] In alternative embodiments, the monitor system may also be
combined with other medical devices to accept other patient data
through a common data network and/or telemetry system. For example,
a glucose monitor may be combined with a blood glucose meter to
directly import or correlate glucose calibration reference values
such as described in U.S. patent application Ser. No. 09/334,996,
filed Jun. 17, 1999, entitled "Characteristic Monitor With A
Characteristic Meter and Method Of Using The Same", which is
incorporated by reference herein. The glucose monitor may also be
combined with semi-automated medication infusion pumps of the
external type, as generally described in U.S. Pat. Nos. 4,562,751;
4,678,408; and 4,685,903; or automated implantable medication
infusion pumps, as generally described in U.S. Pat. No. 4,573,994,
which are herein incorporated by reference, or hospital based IV
infusion systems. The glucose monitor may record data from the
infusion pumps and/or may process data from both the glucose sensor
114 and an infusion pump to establish a closed loop system to
control the infusion pump based on glucose sensor measurements. In
other embodiments, other body characteristics are monitored, and
the monitor may be used to provide feedback in a closed loop system
to control a drug delivery rate.
[0089] As shown in FIG. 11, a second lumen 106 is provided in the
central line catheter 100 for the purpose of delivering medication
directly to a main artery or vein near the heart. In preferred
embodiments an orifice 108 is used to release medication into the
bloodstream, and a Luer fitting 104 is used to connect with an
infusion pump, IV drip, or syringe port. However, in alternative
embodiments, more than one orifice 108 can be formed in the second
lumen 106 to deliver medication into the bloodstream. In addition,
the connection fitting between the second lumen 106 and the
infusion device can be a plug-in connector is similar to a
jack/plug combination, a septum cap, or other similar device
instead of Luer fitting.
[0090] In preferred embodiments, the orifice 108 of the second
lumen 106 is located a set distance closer to the proximal end of
the central line 100 than the sensor orifice 112 of the first lumen
110. By ensuring that the orifice 108 is further downstream of the
blood flow compared to the sensor orifice 112, the sensor 114 is
ensured that any readings taken by the sensor 114 will not be
corrupted or distorted by the delivery of any form of medication
from the orifice 108. FIG. 12 describes a study performed using the
central line 100 with an analyte sensor 114 to prove that no
interference occurs between the drug infusion (or any other type of
infusion) and the sensor reading. The study of FIG. 12 used a
glucose sensor 114 to detect if there were any differences in
response when administering a dextrose solution (i.e., a
concentrated glucose solution) through a peripheral location (i.e.,
saphenous infusion) versus administering through the central line
catheter 100. The study showed that there was no interference
between the delivery of dextrose solution and the sensor 114 using
the central line catheter 100 of the present invention. An
interference would have been detected if a spike in the glucose
readings occurred when the dextrose was administered through the
central line catheter 100.
[0091] Although in the preferred embodiments, a double lumen
central line catheter was shown, any additional number of lumens
could be added to the central line catheter 110. FIGS. 12 and 13
illustrate alternative embodiments of the central line catheter in
accordance with the preferred embodiments of the present invention.
As shown in FIGS. 12 and 13, multiple infusion lumens and multiple
sensors can be placed in the central line catheter. The additional
lumens can be used to deliver other type of fluids, such as, but
not limited to, saline, vitamins, drugs, medication, proteins,
peptides, insulin, neural transmitters, or the like, as needed to
the patient. Additional sensors can be added to detect different
characteristics from the body of the patient. In addition, in
alternative embodiments, additional lumens can be used to perform
other functions. For example, additional smaller lumens can be
located within the first lumen 110 or second lumen 106 of FIG. 11
to deliver saline or other suitable cleansing fluid to clean the
orifices 108 or 112 in case clotting agents, proteins, fats, or
other substances in the blood tend to cover the orifices 108 and
112. Alternatively, a flush sleeve can be placed around the entire
central line catheter 100, as described in U.S. patent application
Ser. No. 10/034,740, filed Dec. 27, 2001, entitled "Implantable
Sensor Flush Sleeve," which is incorporated by reference herein.
The flush sleeve will be have orifices directed where the sensor
would take readings and/or where the central line catheter would
deliver the medications.
[0092] FIG. 15 is a cross-sectional view of the central line along
line #1 of FIG. 11, in accordance with the preferred embodiments of
the present invention. FIG. 15 illustrates how the unsealed portion
of the second lumen 106 extends past the location of the sensor in
the first lumen 110, ensuring that the sensor orifice 112 is
located downstream of the infusion orifice 108.
[0093] FIG. 16 is a cross-sectional view of the central line along
line #2 of FIG. 11, in accordance with the preferred embodiments of
the present invention. FIG. 16 illustrates how the central line
catheter 100 can be modified to include the sensor 114 without
increasing the typical size of a double lumen catheter. By reducing
the size of the second lumen 106 along the portion of the length of
the first lumen 110 containing the sensor 114, the sensor 114 can
be easily accommodated in the central line catheter 100.
[0094] Thus, the analyte sensor can be combined within a central
line catheter to measure an analyte level in vivo in the body of a
patient, while administering other fluids through the central line
catheter.
[0095] Although the preferred embodiments described the ability use
a central line catheter to administer medications while collecting
characteristic data through a sensor, other modifications are
possible to the device to perform other functions. The central line
catheter can also be used to sample directly from the patient's
body. Thus, the ability to sense, sample, and infuse provides a
wide range of diagnostic and therapeutic options. In addition,
various combinations of the features can be used. For example, the
central line catheter can sense what is being infused, infuse an
agent which positively or negatively impacts what is being sensed,
or sensing, infusing and sampling can be unrelated.
[0096] While particular embodiments of the present invention have
been shown and described, it will be obvious to those skilled in
the art that the invention is not limited to the particular
embodiments shown and described and that changes and modifications
may be made without departing from the spirit and scope of the
appended claims.
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