U.S. patent application number 11/402158 was filed with the patent office on 2006-08-10 for vascular access port with physiological sensor.
This patent application is currently assigned to Transoma Medical, Inc.. Invention is credited to H. Clark Adams, Brian P. Brockway, Perry A. Mills.
Application Number | 20060178617 11/402158 |
Document ID | / |
Family ID | 31992310 |
Filed Date | 2006-08-10 |
United States Patent
Application |
20060178617 |
Kind Code |
A1 |
Adams; H. Clark ; et
al. |
August 10, 2006 |
Vascular access port with physiological sensor
Abstract
A combined vascular access port and physiologic parameter
monitoring device. The vascular access port and the monitoring
device may be connected by a cooperative geometry. The vascular
access port and the monitoring device may be implanted at the same
time and in the same anatomical location (e.g., subcutaneous
pocket). The monitoring device may include a telemetry unit that
transmits physiological measurement data to a local data collection
system (e.g., carried by the patient or located in the patient's
home), which may re-transmit the data to a remote data collection
system (e.g., located at a physician's office or clinic) via a
suitable communication link.
Inventors: |
Adams; H. Clark; (Arden
Hills, MN) ; Brockway; Brian P.; (Shoreview, MN)
; Mills; Perry A.; (Arden Hills, MN) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Transoma Medical, Inc.
St. Paul
MN
|
Family ID: |
31992310 |
Appl. No.: |
11/402158 |
Filed: |
April 10, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10246348 |
Sep 17, 2002 |
|
|
|
11402158 |
Apr 10, 2006 |
|
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Current U.S.
Class: |
604/65 ; 128/903;
128/904; 128/DIG.13; 600/300 |
Current CPC
Class: |
A61B 5/14532 20130101;
A61B 5/318 20210101; A61B 5/145 20130101; A61B 5/0215 20130101;
A61M 2230/202 20130101; A61M 2230/00 20130101; A61B 5/02055
20130101; A61M 39/0208 20130101; A61M 2039/0229 20130101; A61M
2205/3553 20130101; A61M 2230/30 20130101; A61M 2205/3523 20130101;
A61B 5/0028 20130101; A61M 2230/205 20130101; A61M 2230/50
20130101; A61M 2205/3368 20130101; A61B 5/0031 20130101; A61B
5/0008 20130101; A61M 2205/3561 20130101 |
Class at
Publication: |
604/065 ;
128/DIG.013; 128/903; 128/904; 600/300 |
International
Class: |
A61M 31/00 20060101
A61M031/00 |
Claims
1. A vascular access port and sensor system, comprising: a vascular
access port including a portal housing; and a physiological sensor
device disposed adjacent the vascular access port, the sensor
device including a sensor and a sensor housing, wherein the sensor
housing and the portal housing define cooperative geometries.
2. The vascular access port and sensor system of claim 1, wherein
the vascular access port contains an internal reservoir with first
and second openings, a self-sealing septum disposed in the first
opening, and a catheter extending from the portal housing, the
catheter defining a lumen extending therethrough in fluid
communication with the reservoir via the second opening.
3. The vascular access port and sensor system of claim 1, wherein
the sensor device includes a pressure sensor.
4. The vascular access port and sensor system of claim 1, wherein
the sensor device includes a temperature sensor.
5. The vascular access port and sensor system of claim 1, wherein
the sensor device includes an impedance sensor.
6. The vascular access port and sensor system of claim 1, wherein
the sensor device includes a blood gas sensor.
7. The vascular access port and sensor system of claim 1, wherein
the sensor device includes an ECG sensor.
8. The vascular access port and sensor system of claim 1, wherein
the sensor device includes a plurality of sensors.
9. The vascular access port and sensor system of claim 1, wherein
the sensor housing is fixedly connected to the portal housing.
10. The vascular access port and sensor system of claim 9, wherein
the sensor housing is integrally formed with the portal
housing.
11. The vascular access port and sensor system of claim 1, wherein
the sensor housing is releasably connected to the portal
housing.
12. The vascular access port and sensor system of claim 11, wherein
the sensor housing interlocks with the portal housing.
13. The vascular access port and sensor system of claim 11, wherein
the cooperative geometries are defined by a connector extending
from the sensor housing and the portal housing.
14. The vascular access port and sensor system of claim 13, wherein
the connector defines a lumen extending therethrough.
15. The vascular access port and sensor system of claim 14, wherein
the lumen of the connector is in fluid communication with the
internal reservoir.
16. The vascular access port and sensor system of claim 1, further
comprising a telemetry unit connected to the sensor device.
17. The vascular access port and sensor system of claim 16, wherein
the sensor generates a sensor signal as a function of a
physiological parameter, and wherein the telemetry unit generates a
transmission signal as a function of the sensor signal.
18. The vascular access port and sensor system of claim 17, further
comprising a local data collection system having a communication
link with the telemetry unit.
19. The vascular access port and sensor system of claim 18, further
comprising a remote data collection system having a communication
link with the local data collection system.
20. A vascular access port and sensor system, comprising: a
vascular access port including a portal housing containing an
internal reservoir with first and second openings, a self-sealing
septum disposed in the first opening, a catheter extending from the
portal housing, the catheter defining a lumen extending
therethrough in fluid communication with the reservoir via the
second opening, and a first connector connected to the portal
housing; and a pressure sensor device disposed adjacent the
vascular access port, the sensor device including a pressure sensor
disposed in a sensor housing, a pressure transmission catheter
extending from the sensor housing and being in fluid communication
with the pressure sensor, and a second connector connected to the
sensor housing; wherein the first and second connectors define
cooperative geometries.
21. The vascular access port and sensor system of claim 20, wherein
the first and second connectors define mating geometries.
22. The vascular access port and sensor system of claim 20, wherein
the first and second connectors define interlocking geometries.
23. The vascular access port and sensor system of claim 20, wherein
the sensor housing and the portal housing are releasably
connected.
24. The vascular access port and sensor system of claim 20, wherein
the sensor housing and the portal housing are fixedly
connected.
25. The vascular access port and sensor system of claim 20, further
comprising a telemetry unit connected to the sensor device.
26. The vascular access port and sensor system of claim 25, wherein
the pressure sensor generates a sensor signal as a function of
blood pressure, and wherein the telemetry unit generates a
transmission signal as a function of the sensor signal.
27. A surgical method of implanting a vascular access port and a
sensor device, comprising: providing a vascular access port
including a portal housing containing an internal reservoir with
first and second openings, a self-sealing septum disposed in the
first opening, and a catheter connected to the portal housing, the
catheter defining a lumen extending therethrough in fluid
communication with the reservoir via the second opening; providing
a physiological sensor device including a sensor and a sensor
housing; surgically forming a subcutaneous pocket through an
incision; introducing the catheter of the vascular access port into
a vascular lumen; placing the portal housing is the subcutaneous
pocket; placing the sensor device in the subcutaneous pocket; and
surgically closing the incision.
28. The surgical method of claim 27, wherein the sensor device is
placed adjacent the vascular access port.
29. The surgical method of claim 27, wherein the sensor housing and
the portal housing define cooperative geometries, and wherein the
cooperative geometries are placed immediately adjacent each
other.
30. The surgical method of claim 27, wherein the sensor housing and
the portal housing define interlocking geometries, and wherein the
interlocking geometries are interlocked with each other.
31. The surgical method of claim 27, wherein the sensor housing and
the portal housing are releasably connected to each other.
32. The surgical method of claim 27, wherein the sensor housing and
the portal housing are fixedly connected to each other.
33. The surgical method of claim 27, further comprising: providing
a telemetry unit connected to the sensor device; and placing the
telemetry unit in the subcutaneous pocket.
34. A medical treatment method, comprising: providing a vascular
access port including a portal housing containing an internal
reservoir with first and second openings, a self-sealing septum
disposed in the first opening, and a catheter connected to the
portal housing, the catheter defining a lumen extending
therethrough in fluid communication with the reservoir via the
second opening; providing a physiological sensor device including a
sensor and a sensor housing; implanting the vascular access port
and the sensor device; administering a therapeutic agent through
the vascular access port; and monitoring a physiological measure
using the sensor device.
35. The medical treatment method of claim 34, further comprising:
changing the administration of the therapeutic agent as a function
of the monitored physiological measure.
36. The medical treatment method of claim 34, further comprising:
providing a telemetry unit connected to the sensor device;
implanting the telemetry unit; wherein the sensor device generates
a sensor signal as a function the physiological measure; and
wherein the telemetry unit generates a transmission signal as a
function the sensor signal.
37. A sensor device for use with a vascular access port including a
portal housing having a geometry, the sensor device comprising: a
sensor housing; a physiological sensor disposed in the sensor
housing; wherein the sensor housing defines a geometry that is
cooperative with the geometry of the portal housing.
38. The sensor device of claim 37, further comprising a telemetry
unit carried by the sensor housing.
39. A vascular access port for use with a sensor device including a
sensor housing having a geometry, the vascular access port
comprising: a portal housing containing an internal reservoir with
first and second openings; a self-sealing septum disposed in the
first opening; and a catheter extending from the portal housing,
the catheter defining a lumen extending therethrough in fluid
communication with the reservoir via the second opening; wherein
the portal housing defines a geometry that is cooperative with the
sensor housing.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/246,348, filed Sep. 17, 2002, the entire
disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to vascular access
ports. In particular, the present invention relates to vascular
access ports having associated physiological sensors.
[0003] Implantable vascular access ports (VAP) are used extensively
in the medical field when recurrent infusions of therapeutic agents
into a patient's circulatory system are required over extended
periods of time. Such VAPs generally include a housing containing a
reservoir and septum, with a catheter extending from the housing.
The VAP housing is implanted in a subcutaneous pocket at an
accessible location such as the arm, and the catheter extends from
the housing to a remote vascular location to provide convenient,
repeatable access to the patient's venous or arterial system in the
body. In the subcutaneous pocket, the septum of the VAP may be
pierced by a needle that is coupled via appropriate tubing to a
therapeutic agent source in an intravenous bag or infusion pump,
for example, so that the therapeutic agents may be administered.
Such a vascular access system may be used in the home or other
outpatient settings, as well as inpatient hospital settings.
[0004] When infusing therapeutic agents, it is important to monitor
certain patient physiological parameters in order to assess if the
therapeutic agent is having the desired benefit and/or is causing
detrimental side effects. For example, home infusions of
antibiotics are often prescribed for patients suffering from
aggressive bacterial infections. These infusions are administered
for weeks and then terminated if no apparent clinical symptoms
exist. In some instances, however, patients remain infected even
though no symptoms exist. The residual infection often manifests
itself as random temperature spikes lasting for tens of minutes
(known as infection rebound or breakthrough) and the patient may or
may not be aware of its existence. As such, patient temperature
should be monitored because such temperature spikes should signal
the attending physician to change antibiotics. As another example,
infused inotropic or antihypertensive drugs require patient blood
pressure monitoring because of possible hypo or hypertension side
effects that may be life threatening.
[0005] Conventional options for monitoring temperature include
oral, rectal, ear or skin type temperature measurement devices.
Blood pressure monitoring typically includes a blood pressure cuff
device. In addition to inconvenience, these devices are not
desirable due to lack of continuous monitoring and lack of patient
compliance in outpatient settings. For example, because temperature
spikes only last a brief period of time as discussed above,
periodic monitoring may not catch the temperature spike.
Furthermore, because these monitoring devices require patient use,
and because typical patients do not have professional health care
training, the devices are susceptible to incorrect usage,
potentially resulting in erroneous measurements.
[0006] Thus, there is a need for a monitoring device that is
convenient to the patient as well as the physician, provides the
potential for continuous monitoring, and reduces patient
non-compliance.
BRIEF SUMMARY OF THE INVENTION
[0007] To address this need and others, the present invention
provides, in one exemplary embodiment, a vascular access port and
physiologic parameter (e.g., temperature, blood pressure, etc.)
monitoring device that may be inter-connected by a cooperative
geometry. The inter-connected vascular access port and monitoring
device may be implanted at the same time and in the same anatomical
location (e.g., subcutaneous pocket). The monitoring device may
include a telemetry unit that transmits physiological measurement
data to a local data collection system (e.g., carried by the
patient or located in the patient's home), which may re-transmit
the data to a remote data collection system (e.g., located at a
physician's office or clinic) via a suitable communication
link.
[0008] Because the combined vascular access port and monitoring
device may be implanted at the same time and in the same anatomical
location, it is very convenient for the physician and procedurally
cost effective. Also, because the monitoring device does not
require patient involvement for effective use, it is not as
susceptible to patient non-compliance as prior art monitoring
devices. In addition, because the monitoring device permits
continuous feedback; it is possible to detect patient symptoms that
may occur infrequently and for short periods of time. Furthermore,
because the monitoring device permits multiple measurements over a
long period of time, it is possible to improve accuracy of
measurements that lack repeatability by averaging multiple
measurements over a period of time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic plan view of a vascular access port
and physiological monitoring system in accordance with a generic
embodiment of the present invention;
[0010] FIG. 2A is a schematic view of a vascular access port and
physiological monitoring apparatus connected together by a
connector element;
[0011] FIG. 2B is a schematic view of a vascular access port and
physiological monitoring apparatus connected together by a
cooperative geometry;
[0012] FIGS. 3A-3D are schematic illustrations of various connector
element designs for use in the vascular access port and
physiological monitoring apparatus illustrated in FIG. 2A;
[0013] FIG. 4 is a schematic illustration of a vascular access port
for use in the present invention;
[0014] FIG. 5 is a schematic illustration of a physiological
monitoring apparatus for use in the present invention;
[0015] FIG. 6 is a perspective view of a vascular access port and
physiological monitoring apparatus in accordance with a specific
embodiment of the present invention;
[0016] FIG. 7 is an exploded perspective view of the vascular
access port and physiological monitoring apparatus illustrated in
FIG. 6;
[0017] FIG. 8 is a block diagram of the electronics of a
physiological monitoring apparatus and associated transceiver for
use with the embodiment illustrated in FIG. 6;
[0018] FIG. 9A is a perspective view of a pressure transmission
catheter having an antenna for use with the physiological
monitoring apparatus illustrated in FIG. 6;
[0019] FIG. 9B is an end view of the pressure transmission catheter
and antenna illustrated in FIG. 9A;
[0020] FIG. 10A is an end view of an alternative embodiment of a
pressure transmission catheter having an antenna;
[0021] FIG. 10B is an end view of another alternative embodiment of
a pressure transmission catheter having an antenna;
[0022] FIG. 11A is a perspective view of a vascular access port and
physiological monitoring apparatus having an alternative connector
element;
[0023] FIG. 11B is a perspective view of a vascular access port and
physiological monitoring apparatus having another alternative
connector element;
[0024] FIG. 11C is a perspective view of a vascular access port and
physiological monitoring apparatus connected together by a
cooperative geometry;
[0025] FIG. 12 is an exploded perspective view of an alternative
embodiment of a vascular access port and physiological monitoring
apparatus connected together by a common or integral housing;
and
[0026] FIG. 13 is an exploded perspective view of another
alternative embodiment of a vascular access port and physiological
monitoring apparatus connected together by a common or integral
housing.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The following detailed description should be read with
reference to the drawings in which similar elements in different
drawings are numbered the same. The drawings, which are not
necessarily to scale, depict illustrative embodiments and are not
intended to limit the scope of the invention.
[0028] With reference to FIG. 1, a schematic plan view of a generic
system including a vascular access port (VAP) 100 and physiological
monitoring apparatus (PMA) 200 is shown. The system may be used to
deliver therapeutic agents via the VAP 100 while monitoring the
patient 10 with the PMA 200. Based on the patient's condition as
measured by the PMA 200, the therapeutic regimen (e.g., dose,
delivery rate, delivery schedule, etc. of therapeutic agent
administered via the VAP 100) may be changed as needed. For
example, if the patient 10 adversely reacts to the therapeutic
agent delivered via the VAP 100 as measured by the PMA 200, the
dose or delivery rate may be decreased or even terminated to reduce
or eliminate the adverse effect. Also by way of example, if the
patient 10 is not responding to the therapeutic agent delivered via
the VAP 100 as measured by the PMA 200, the dose or delivery rate
may be increased to establish the desired therapeutic effect.
Further by way of example, if the patient 10 demonstrates a need
for therapeutic intervention as measured by the PMA 200, the
administration of therapeutic agent may be initiated via the VAP
100.
[0029] In these and other modes of operation, the PMA 200 provides
feedback as to the condition of the patient 10 as indicated by
measuring one or more physiological parameters such as blood
pressure (arterial, venous, pulse pressure, etc.), temperature,
ECG, blood flow velocity, impedance, blood gas levels, blood gas
constituents, etc., or combinations thereof. The feedback provided
by the PMA 200 may be used to automatically or manually modify the
therapeutic regimen (i.e., delivery parameters of the therapeutic
agent administered via the VAP 100) as described above.
Alternatively, the PMA 200 may provide measurement data indicative
of the patient's condition independent of the therapy administered
via the VAP 100.
[0030] In addition to the VAP 100 and PMA 200, the generic system
illustrated in FIG. 1 may include a home (local) data collection
system (HDCS) 300 which is operably connected to the PMA 200 via
communication link 400, in addition to a physician (remote) data
collection system (PDCS) 500 which is operably connected to the
HDCS 300 via communication link 600. Communication link 400 may
comprise a direct connection (e.g., hardwired transdermal, ohmic,
galvanic or body bus) or an indirect (wireless) connection (e.g.,
radiofrequency, ultrasonic, or infrared transmission). By way of
example, not limitation, the communication link 400 may be provided
via a conductive needle (not shown) inserted into the VAP 100,
wherein the needle is electrically coupled to the HDCS 300 via a
wired connection, and electrically coupled to the PMA 200 via a
conductive septum, for example. Similarly, communication link 600
may comprise a direct (hardwired) or indirect (wireless)
connection, optionally making use of a telecommunication system
such as the Internet.
[0031] The HDCS 300 may be carried by the patient or may be located
in the patient's home, and receives signal data from the PMA 200
via communication link 400. The HDCS 300 may process and store the
signal data, and may optionally provide a visual display of the
measured parameter and/or an audible alarm indicative of the
measured parameter triggering a threshold value. Optionally, the
HDCS may obtain an externally derived parameter (e.g., ambient
pressure) and associate the external parameter with the signal data
from the PMA 200. The data collected and processed by the HDCS 300
may be transferred to the PDCS 500 via communication link 600,
which may be located at a physician's office or clinic. The PDCS
500 may further process and store the signal data, and may also
provide a visual display of the measured parameter and/or an
audible alarm indicative of the measured parameter triggering a
threshold value.
[0032] Based on information provided by HDCS 300, the patient 10 or
the patient's care taker may manually alter the therapeutic regimen
as described above. Similarly, based on information provided by
PDCS 500, the physician or health care provider may contact (via
HDCS 300, for example) and instruct the patient 10 or the patient's
care taker to manually alter the therapeutic regimen as described
above. Alternatively, if the therapeutic agent is delivered to the
VAP 100 by an automated infusion pump or the like, the HDCS 300 may
be operably coupled to the infusion pump and may be programmed to
modify the delivery parameters as a function of the physiological
parameter measured by the PMA 200 and/or as a function of
instructions provided by PDCS 500. Further aspects of the function
and use of HDCS 300 and PDCS 500 may be found in U.S. patent
application Ser. No. 10/077,566, filed Feb. 15, 2002, entitled
DEVICES, SYSTEMS AND METHODS FOR ENDOCARDIAL PRESSURE MEASUREMENT,
the entire disclosure of which is incorporated herein by
reference.
[0033] With reference to FIGS. 1, 2A, 2B, and 4, the VAP 100 is
shown schematically and may comprise a variety of vascular access
port (single or dual port) designs known to those skilled in the
art, with certain modification as described in more detail
hereinafter. In the illustrated embodiment, the VAP 100 includes a
portal housing 102 and an elongate tubular infusion catheter 104
extending therefrom. An internal reservoir 110 (visible in FIG. 4)
is contained within the housing 102. The housing 102 includes two
openings, both of which are in fluid communication with and provide
access to the internal reservoir 110. A side opening in the housing
102 permits passage of the infusion catheter 104 which is in fluid
communication with the internal reservoir 110. The side opening in
the housing 102 may contain a catheter connector and/or strain
relief 108 (visible in FIGS. 2A, 2B and 4). A top opening in the
housing 102 contains a self-sealing septum 106 through which a
hypodermic or infusion needle may be removably inserted into the
internal reservoir 110 for the delivery of therapeutic agents. An
example of a suitable VAP 100, with some modification, is disclosed
in U.S. Pat. No. 5,387,192 to Glantz et al., the entire disclosure
of which is incorporated herein by reference. As an option, the VAP
100 may incorporate a needle detector device as described in U.S.
patent application Ser. No. 10/246,324, entitled VASCULAR ACCESS
PORT WITH NEEDLE DETECTOR, filed on even date herewith, the entire
disclosure of which is hereby incorporated by reference.
[0034] With reference to FIGS. 1, 2A, 2B, and 5, the PMA 200 is
shown schematically and may comprise a variety of implantable
sensor devices known to those skilled in the art, with certain
modification as described in more detail hereinafter. Examples of
implantable devices that measure blood pressure are described in
U.S. Pat. No. 4,846,191 to Brockway et al., U.S. Pat. No. 6,033,366
to Brockway et al., U.S. Pat. No. 6,296,615 to Brockway et al., and
PCT Publication WO 00/16686 to Brockway et al., the entire
disclosures of which are incorporated herein by reference. Other
implantable sensor devices that measure temperature, ECG, blood
constituents, etc., may be implemented as well. An example of an
implantable device with a temperature sensor is described in U.S.
Pat. No. 5,535,752 to Halperin et al., the entire disclosure of
which is incorporated herein by reference. An example of an
implantable device with temperature, pH and pressure sensing
capabilities is disclosed in U.S. Pat. No. 6,285,897 to Kilcoyne et
al., the entire disclosure of which is incorporated herein by
reference. An example of an implantable device with blood flow
velocity measuring capabilities is disclosed in U.S. Pat. No.
5,522,394 to Zurbrugg, the entire disclosure of which is
incorporated herein by reference. An example of an implantable
device with blood constituent (e.g., blood glucose, blood gas)
measuring capabilities is disclosed in U.S. Pat. No. 6,122,536 to
Sun et al., the entire disclosure of which is incorporated herein
by reference. The sensor components (transducer and pressure
transmission catheter) of the PMA 200 may be replaced by the sensor
components of the implantable sensor devices described in the
patents identified above. In some instances, the transducer may be
located on the PMA housing 202, or on a catheter or lead extending
therefrom. In other instances, the transducer may be located on the
VAP housing 102 or the catheter 104 extending therefrom.
[0035] For purposes of illustration, the present invention is
described herein primarily with reference to embodiments utilizing
a PMA 200 that measures blood pressure as described in Brockway et
al. '191. To this end, in the embodiment illustrated in FIGS. 1,
2A, 2B, and 5, the PMA 200 comprises a blood pressure measuring
device including a sensor housing 202 with a pressure transmission
catheter (PTC) 204 extending therefrom. The PMA 200 also includes a
pressure transducer and electronics module 210, a telemetry unit
220 and a power supply 230 (e.g., battery, external power source
with transdermal connection, etc.) contained in housing 202
(visible in FIG. 5).
[0036] The housing 202 protects the pressure transducer and the
electronics module 210, the telemetry unit 220, and the power
supply 230 from the harsh environment of the human body. The
housing 202 may be fabricated of a suitable biocompatible material
such as titanium or ceramic and may be hermetically sealed. If
metallic, the outer surface of the housing 202 may serve as an
electrocardiogram (ECG) sensing electrode. The housing may include
one or more rings (not shown) and/or a mesh fabric (not shown)
disposed thereon for attachment to bodily tissue in the
subcutaneous pocket.
[0037] The PTC 204 refers pressure from the pressure measurement
site to the pressure transducer and electronics module 210 located
inside the sensor housing 202. The PTC 204 may comprise a tubular
structure with a liquid-filled lumen extending therethrough to a
distal opening or port. The proximal end of the PTC 204 is
connected to the pressure transducer via a nipple tube, thus
establishing a fluid path from the pressure transducer to the
distal end of the PTC 204. A barrier such as a viscous or movable
plug and/or membrane may be disposed in the distal opening of the
PTC 204 to isolate the liquid-filled lumen of the PTC 204 from
bodily fluids, without impeding pressure transmission
therethrough.
[0038] As an alternative, the PTC 204 of the PMA 200 and the
infusion catheter 104 of the VAP 100 may be combined into one dual
lumen tube, wherein the PMA 200 measures blood pressure and the VAP
100 delivers therapeutic agent in the same blood vessel. As another
alternative, the PTC 204 the infusion catheter 104 may be combined
into a single lumen tube, wherein a valve is used to alternatively
provide fluid communication between the PMA 200 and the single
lumen catheter to measure blood pressure, and provide fluid
communication between the VAP 100 and the single lumen catheter to
deliver therapeutic agent. In addition or in the alternative, the
PMA 200 may be used to measure fluid flow and/or pressure in the
VAP 100 during infusion, in addition to measuring a physiological
parameter.
[0039] The pressure transducer and electronics module 210 may be
the same or similar to those described in U.S. Pat. Nos. 4,846,191,
6,033,366, 6,296,615 or PCT Publication WO 00/16686, all to
Brockway et al. The electronics module provides excitation to the
pressure transducer, amplifies the pressure signal, and may
digitally code the pressure information for communication to the
telemetry unit 220. The electronics module may also provide for
temperature compensation of the pressure transducer and provide a
calibrated pressure signal.
[0040] The telemetry unit 220 includes telemetry electronics, which
may be the same or similar to those described in U.S. Pat. Nos.
4,846,191, 6,033,366, 6,296,615 or PCT Publication WO 00/16686, all
to Brockway et al. The telemetry unit 220, receives a physiological
parameter (e.g., pressure) signal from the pressure transducer and
electronics module 210, and transmits the data signal to the HDCS
300 via communication link 400. In addition or in the alternative,
the telemetry unit 220 may include memory interrogatable by the
HDCS 300. Communication link 400 may comprise a direct connection
(e.g., hardwired transdermal, ohmic, galvanic or body bus) or an
indirect (wireless) connection (e.g., radiofrequency, ultrasonic,
or infrared transmission). For wireless RF transmission, a
telemetry coil or antenna may be provided in the housing 202, or an
antenna may be provided in the PTC 204 as described in more detail
hereinafter.
[0041] The pressure as measured by the PMA 200 is influenced by
external pressure changes (i.e., barometric pressure) and is
preferably corrected to avoid inaccuracies and/or possible
misinterpretation of pressure data. Barometric pressure can change
significantly when a weather front moves through the area where the
patient resides, when the patient is riding up an elevator in a
tall building or traveling in mountainous areas where changes in
elevation are frequent and significant. Thus, the present invention
provides a number of different pressure correction schemes as
described herein.
[0042] One general approach is to take barometric pressure
measurements simultaneously with measurements taken by the PMA 200,
and subtract the barometric reading from the internal pressure
measurement. For example, the HDCS 300 may take a barometric
pressure reading and subtract the barometric pressure measurement
from the pressure measurement transmitted by telemetry unit 220 of
the PMA 200.
[0043] For example, a barometric pressure monitor (BPM) may be
located external to the body and measure barometric pressure at
times specified by a controller. Measurements obtained by the BPM
are representative of the barometric pressure to which the body of
the patient is exposed. The BPM may be a small device attached to a
belt, worn on the neck as a pendant, on the wrist like a watch, or
placed in a purse or briefcase. The BPM may be incorporated into
the HDCS 300, for example.
[0044] At some time, e.g. the first measurement obtained after the
BPM is powered on, the absolute value of barometric pressure is
stored in the memory of a computing device, which may be
incorporated into the BPM, for example. The absolute value of
barometric pressure is stored in the memory along with a time stamp
(e.g. year, month, day, hour, minute and second). From then on,
each subsequent barometric pressure measurement is compared to the
stored measurement and evaluated to determine if the difference
between that measurement and the stored measurement exceeds a
predetermined threshold (e.g. 0.5 mmHg). If the difference is less
than the threshold, no further action is taken on that measurement.
If the difference is greater than or equal to the threshold, then
that value is saved in memory along with a time stamp. If a chronic
time series is collected from the patient, the memory of the
computing device in the BPM contains barometric pressure values at
each point in time where the pressure changed significantly
(significant as determined by the preset value).
[0045] With this approach, pressure measurements taken by the PMA
200 are made with respect to a specific reference pressure,
normally to a vacuum. Pressure measurements are recorded into
memory in the PMA 200. Measurements are stored in a way that allows
the date and time of the recording to be established. At various
times, the pressure measurements recorded in the PMA 200 are
transferred to an external combining device (CD) through means of a
wireless link. The CD may also be incorporated into the HDCS 300,
for example, and the BPM also has the ability to transfer
measurements to the CD. This transfer can be made through a hard
link (e.g., electrically conductive wires or fiber optics) if the
BPM and CD are in the same unit such as HDCS 300, or via a wireless
link (e.g., RF transmission) if the BPM and CD are remote from each
other. Once data from both the PMA 200 and the BPM are transferred
to the CD, the CD can correct the measurements obtained from the
PMA 200 for barometric pressure. Knowing the barometric pressure
measurements at the starting time and at each point thereafter when
pressure changes by a significant amount, it is possible to know
the barometric pressure at any time up until the date and time of
the last value recorded in memory. Correction of a measurement from
the PMA 200 for barometric pressure can be achieved by subtracting
the barometric pressure measurement reconstructed at that time
point, or by mathematically manipulating the two time series to
achieve a result equivalent to subtraction.
[0046] A variation of this approach is to record corrected
measurements within the PMA 200. In some cases it is useful to have
the corrected pressure measurements available within the PMA 200,
such as when the PMA 200 is in communication with a device that is
providing therapeutic effect, such as an infusion pump, pacemaker
or defibrillator, and is relying on accurate pressure measurements
to adjust the therapy parameters. Such a therapeutic device may be
implanted or external (e.g., a drug infusion pump or wearable
defibrillator).
[0047] The BPM may transmit barometric pressure data to the PMA
200, which subtracts the barometric measurement from the in vivo
pressure measurement and utilizes or otherwise stores the corrected
measurement. Alternatively, the in vivo pressure measurements may
be transmitted to the BPM which corrects the pressure measurement
from the PMA 200 for barometric pressure and transmits the
corrected pressure measurement back into the PMA 200.
[0048] Alternately, the BPM may evaluate the barometric pressure
measurements as they are obtained. In this alternative embodiment,
the BPM would transmit the barometric pressure to the PMA 200 when
it is first turned on or brought into the receiving range of the
BPM. Once this initial measurement is received by the PMA 200, if a
measurement differs from the previous value by more than a
predetermined threshold, then (and only then) would the BPM
transmit a barometric pressure measurement to the PMA 200. The PMA
200 would then send a confirming transmission to the BPM indicating
that the transmission of barometric pressure was correctly
received. The BPM may continue to send the measurement at regular
internals until such confirmation is received.
[0049] Another general approach is to provide a reference pressure
for the PMA 200. For example, a barometric reference pressure may
be provided via a needle inserted into a reference septum in the
PMA 200 as described with reference to FIGS. 6 and 7.
Alternatively, a barometric reference pressure may be provided via
a needle inserted into the septum of the VAP 100, which is in fluid
communication with the PMA 200 as described with reference to FIG.
2A.
[0050] With reference back to FIG. 1, the VAP 100 is shown
implanted with the housing 102 in a subcutaneous pocket and the
catheter 104 inserted in a vein. Similarly, the PMA 200 is shown
connected to and adjacent the VAP 100 in the same subcutaneous
pocket, with the PTC 204 disposed in an artery. Those skilled in
the art will recognize that the VAP 100 may be implanted in a
variety of subcutaneous locations, and that the infusion catheter
104 may be inserted at a variety of venous locations with varying
access and terminus sites. Similarly, those skilled in the art will
recognize that PMA 200 may be implanted in a variety of
subcutaneous locations, and that the PTC 204 may be inserted at a
variety of vascular lumens, organ cavities, interstitial spaces
etc., depending on the type of sensor utilized and the type of
physiological parameter measured. In addition, because some types
of sensors do not require a PTC 204, the PMA 200 may exclude the
PTC 204 and simply be implanted adjacent the VAP 100.
[0051] In the specific implant example shown in FIG. 1, the
infusion catheter 104 of the VAP 100 may be disposed in the basilic
vein 24 or cephalic vein 26 which converge into the auxiliary vein
22. The infusion catheter 104 may extend through the auxiliary vein
22 and the superior vena cava 20, and into the right atrium or
right ventricle of the heart 12. The PTC 204 of the PMA 200 may be
disposed in the brachial artery 18 which communicates with the left
ventricle of the heart 12 via aortic arch 14 and subclavian artery
16. Although the patient 10 in this example is shown as a human,
the present invention is equally applicable to other animals as
well.
[0052] With reference to FIGS. 2A and 2B, the VAP 100 and PMA 200
are connected together by a cooperative connector geometry and a
cooperative housing geometry, respectively. In FIG. 2A, the
cooperative geometry is defined external of the port housing 102
and sensor housing 202. In FIG. 2B, the cooperative geometry is
defined internally by one of the VAP 100 and PMA 200, and
externally by the other. As used herein, the term cooperative
geometry or geometries refers to geometries that limit relative
movement along two or more orthogonal directions or axes. For
example, mating geometries and interlocking geometries, whether
fixed together or separable, comprises cooperative geometries.
[0053] With specific reference to FIG. 2A, the connector element
150 includes a port portion 148 and a sensor portion 152, each of
which define geometries that are cooperative. The port portion 148
of the connector element 150 may be connected to the port housing
102, and may be a separate or an integral component. Similarly, the
sensor portion 152 of the connector element 150 may be connected to
the sensor housing 202, and may be a separate or an integral
component.
[0054] Examples of such connector elements 150 with cooperative
geometries are shown in FIGS. 3A-3D. In FIG. 3A, the connector
element 150A defines a dove-tail interlocking geometry. In FIG. 3B,
the connector element 150B defines a ball-and-socket interlocking
geometry. In FIG. 3C, the connector element 150C defines a snap-fit
(tapered ridge in groove) geometry. In FIG. 3D, the connector
element 150D comprises a threaded shaft and bore geometry.
[0055] Connector element 150 may optionally incorporate a lumen 158
through which a fluid path may be established between the VAP 100
and the PMA 200. The lumen 158 may be used, for example, for
measuring the pressure or flow rate of fluid infused through VAP
100 utilizing PMA 200, for providing a reference pressure to the
PMA 200 via a secondary port in the VAP 100, or for utilizing a
common catheter for infusion and pressure measurement.
[0056] With specific reference to FIG. 2B, the port housing 102 and
the sensor housing 202 define cooperative geometries. As shown, the
VAP 100 defines an external geometry which cooperates with an
internal geometry of the PMA 200. It is also possible to have the
PMA 200 define an external geometry which cooperates with an
internal geometry of the VAP 100. In the illustrated embodiment,
the PMA 200 defines a cylindrical hole or recess 206 which
accommodates the cylindrical housing 102 of the VAP 100, in
addition to the infusion catheter 104 and the catheter
connector/strain relief 108.
[0057] FIGS. 1-5 and the corresponding text schematically
illustrate and describe generic embodiments of the present
invention. Reference may be made to FIGS. 6-13 for detailed
embodiments that incorporate the general principles discussed
above.
[0058] With specific reference to FIG. 6, a combined vascular
access port and physiological monitoring apparatus is shown
generally as 710. The system 710 includes a vascular access port
(VAP) 712 and physiological monitoring apparatus (PMA) 714. An
exploded view of the combined VAP and PMA 710 is shown in FIG.
7.
[0059] A housing, comprising a mating cap 718 and base 720 pair,
contains the internal components of both the VAP 712 and PMA 714.
In this embodiment, the cap 718 is an integrally formed component
that includes the side-by-side, generally cylindrical vascular
access port portion 722 and the generally triangular-solid shaped
PMA portion 724. A plurality of suture holes 726 are provided in
the base 720 for securing the housing 718/720 to bodily tissue
during surgical implantation thereof.
[0060] The VAP 712 includes an infusion catheter 728 that extends
from the VAP housing 722. A proximal end 730 of the infusion
catheter 728 is connected to and is in fluid communication with a
reservoir 754, and a distal end 732 of the catheter 728 is disposed
in the patient's vascular system. The therapeutic agent is
delivered to the infusion catheter 728 via a needle (not shown),
coupled via appropriate tubing to a therapeutic agent source in an
intravenous bag or infusion pump, for example, that penetrates the
infusion septum 734 and communicates with reservoir 754.
[0061] The PMA 714 includes a pressure transmission catheter (PTC)
736 coupled at its proximal end 738 to the pressure transducer and
electronics package 760 for measuring an internal body pressure.
Such pressure might include, but is not limited to, arterial
pressure, venous pressure, cardiac chamber pressure, intracranial
pressure, intrauterine pressure, bladder pressure, or intrapleural
pressure. The PTC 736 may comprise the type described in Brockway
'191 or the type described in Brockway '366, for example. A
pressure reference septum 740 is provided that is penetrable by a
needle (not shown) for providing a reference pressure, such as
atmospheric pressure.
[0062] In this manner, a combined VAP and PMA 710 is disclosed that
allows the combined convenience of a VAP and the simultaneous
ability to monitor a physiological parameter of a patient without
requiring a practitioner to independently monitor the parameter. It
also allows this to be accomplished in a single surgical procedure
which presents virtually no additional surgical effort on behalf of
the surgeon who would otherwise have implanted a VAP. It adds
virtually no additional procedure time or expense either.
[0063] Although various geometries are possible, the cap 718 may be
generally about 25 mm in length (l), about 12 mm in width (w), and
about 15 mm in height (h). The cap 718 may be formed of a titanium,
titanium-plastic combination or a titanium-ceramic combination. Two
access ports (holes) in the cap 718, infusion septum access port
742 and pressure reference septum access port 744, provide needle
access during use to the infusion septum 734 and pressure reference
septum 740, respectively. In one embodiment, the septa are formed
of a silicone elastomeric material. The septa are mechanically
secured when the cap 718 is mated to the base 720.
[0064] In the embodiment shown, the cap 718 mates with the base 720
by pinching an edge 746 of the cap 718 between a wall periphery 748
of the base 720 and a plurality of tabs 750. The distance of the
tabs 750 from the wall periphery 748 may be selected relative to
the thickness of the edge 746 of the cap 718 to form a snug
interference fit. The cap 718 and the base 720 may further be
adhesively bonded and sealed with a suitable biocompatible
adhesive.
[0065] When mated, the infusion septum 734 overlays a top 752 of
the fluid reservoir 754. In this manner, a needle may penetrate the
infusion septum 734 and deliver a therapeutic agent to the fluid
reservoir 754. In turn, the therapeutic agent is delivered to the
patient via the infusion catheter 728 which is in fluid
communication with the fluid reservoir 754.
[0066] The pressure reference septum 740 is secured between a
clamshell structure 756 of the base 720 and a curved portion 758 of
the cap. In this manner, it will be appreciated that atmospheric
pressure (reference pressure) may be provided via a needle
penetrating the pressure reference septum 740 of the PMA 714, which
avoids the use of elaborate barometric pressure reference devices
when measuring arterial or venous pressure.
[0067] The PTC 736 is connected to the base 720 via a retaining
mechanism 759. The pressure transducer and electronics package 760,
powered by battery source 762, is coupled to the PTC 736. A
substrate 764 may support the electronics package 760 and rest on
the floor 766 of the base 720 housing.
[0068] With reference to FIG. 8, the pressure transducer and
electronics module 760 of the PMA 714 may be implanted within a
patient's body (shown as being to the left side of a dashed line
767 representing the skin surface of the patient) and communicates,
regarding measured physiological parameters, with a transceiver 770
external to the patient's body (shown as being to the right side of
the dashed line 767).
[0069] The pressure transducer and electronics module 760 may
comprise a processor 768 having a memory 772 for permanent or
temporary storage of various algorithms, routines, computer
executable instructions, and/or storage of the measured
physiological parameter. The memory may be any well known
random-access or read-only type memory, or both. A temperature
input (Temp), a body pressure input (Pressure), an
electrocardiogram electrode input (ECG) or other input desired to
be measured by the PMA are supplied to the processor 768 via
appropriate electronic communications paths. Other inputs include,
but are not limited to, blood flow, blood glucose, blood gas (e.g.,
oxygen saturation, CO2).
[0070] The body pressure input may be provided via the PTC 736 and
pressure transducer in module 760 as described with reference to
FIGS. 6 and 7. The temperature input may be received from a
thermistor (not shown) mounted internally or externally to the
housing 718/720. A benefit of locating the thermistor externally to
the housing is to minimize temperature error induced by the
therapeutic agent flowing through the VAP and to obtain temperature
at a very specific body location. The ECG input may be received
from a ECG electrodes mounted on the housing 718/720, the PTC 736,
and/or the infusion catheter 728. For example, ECG electrodes 840
may mounted on a bottom surface 841 of base 720 as shown in FIG.
13.
[0071] The electronics package and battery source may be
hermetically sealed to prevent the electronics from electrically
shorting or corroding as a result of water vapor penetration. The
battery source 762 (rechargeable and/or replaceable) provides the
power input (Pwr) to the electronics package. It may comprise a
physical battery or a capacitor, for example, and may be implanted
with the device or located external to the body and wirelessly
coupled to the electronics package by utilizing a magnetic
coupling, for example. Such a magnetic coupling may utilize an AC
powered primary (external) coil disposed on the skin to create an
alternating magnetic field which induces power in a secondary
(internal) coil connected to the electronics package and disposed
under the skin in close proximity to the primary coil.
[0072] Communicating with the processor 768 via communications
paths 773 is a transmitter 774 and receiver 776 pair. In this
manner, once a physiological parameter of the body is measured, it
can be communicated, in a delayed (requires writable memory
connected processor 768) or immediate fashion, in a continuous or
discrete manner, as processed or raw data, externally to the body
so that a practitioner can use the information in treatment of the
patient. Preferred transmission methods for the transmitter
include, but are not limited to, conduction, radio-frequency waves,
magnetic fields, electric fields, sound waves or light waves.
[0073] The processor 768 may process various information from its
inputs, and may be coupled to a memory storage device (not shown).
For example, it may derive systolic and diastolic pressures, mean
pressures, heart rate and/or respiratory rate in the event its
input included blood pressure waveforms from the pressure input.
Once processed, the transceiver could send requests to the
processor indicative of how often the blood pressure is to be
sampled and which parameters are to be extracted, for example. As
another example, the processor could evaluate its ECG input for
rhythm disturbances.
[0074] In a preferred embodiment, the transceiver 770 includes a
second transmitter 775 and receiver 777 pair. It is powered by an
appropriate power source 778 such as an AC or DC source. Via
communications paths 780, the transmitter 775 and receiver 777
communicate with a second processor 782 having a memory 784. The
processor 782 communicates with a visual display 786 so that the
practitioner can easily see the value of the measured body
physiological parameter. In one embodiment, the display can display
more than one physiological parameter at a time. In another, it can
cycle between pages of displays. An alarm 788 is provided to
aurally and/or visually indicate that one or more of the measured
body physiological parameters has exceeded some acceptably defined
range of values. In this manner, the patient and/or practitioner
can react swiftly in taking corrective action.
[0075] An external connector(s) 790 is provided so that the
transceiver can become more robust. In various embodiments, the
external connector can connect by a direct wire or wireless link,
such as by radio-frequency or infrared, to a printer, a general or
special purpose computer, additional storage devices, faxes,
internet, intranets, cell phone, personal data assistant,
satellite, or other such computing or peripheral devices.
[0076] It will be appreciated the exact embodiment of the
transceiver 770 can embody many forms. For example, in one
embodiment it consists of patient strap-on module. In another, it
is embodied as a wand to be passed over the patient's skin. In
still another, it is coupled physically and electronically together
with an infusion pump.
[0077] The transmitter and receiver pair of the electronics package
760 and the transmitter and receiver pair of the transceiver 770
may communicate via the use of an antenna associated with the PTC
736 or infusion catheter 728. In FIGS. 9A and 9B, and 10A and 10B,
an antenna 800 is shown with PTC 736. The catheter may have a
length (l), and an inner and outer diameter (di and do). The
antenna 800 is disposed along a length thereof in a substantially
straight manner (as shown), spirally wound manner, or may consist
of a plurality of conductors, stranded or braided, to provide
flexibility and ruggedness. A terminal end 802 of the antenna 800
may be disposed in or adjacent the inner diameter (FIG. 9B),
adjacent the-outer diameter. (FIG. 10B), or between the inner and
outer diameters (FIG. 10A). In still other embodiments, the antenna
is disposed along only a portion of the length of the catheter and
a plurality of antennas, instead of just the one shown, are
arranged about the inner and outer diameters of the catheter.
[0078] The transmitter and receiver pairs may include appropriate
modulators, demodulators, amplifiers, oscillators, etc., that are
well known and necessary for transmitting and receiving signals, in
order to accommodate antenna 800. In some embodiments, it will be
appreciated that the electronics package only includes a
transmitter for communicating externally to the body and does not
include a receiver and therefore cannot receive body external
information.
[0079] With reference to FIGS. 11A-11C, it will be appreciated that
the VAP and PMA may, instead of being integrally formed, be
combinable with one another before, during or after surgical
implantation. In such instances, each of the VAP and the PMA have
housings having mating, combinable features. For example, in FIG.
11A, the vascular access port housing 722 is slidingly engaged with
the PMA housing 724 via mating slot 806 and tab 808 features
arranged on an external surface 723, 725 of the VAP and PMA,
respectively. In FIG. 11B, the two housings are combinable in an
interlocking fit configuration as a ball 810 and socket 812. It
will be appreciated that the male/female parts may be switched and
are not limited to the embodiments shown. In FIG. 11C, the two
housings are combinable as a cap 814 over base 816 configuration.
Still other embodiments include, but are not limited to,
one-or-more snap-lock features, tongue-groove configurations, or
other known or hereinafter invented arrangements. In still other
embodiments, the two housings are compatible shapes but are not
positively interlocking, such as with a donut shaped PMA
surrounding a donut-hole shaped VAP. It should also be appreciated
that in any of the foregoing embodiments, more than one PMA may be
combined together with a VAP. Also, when made as combinable
housings, flexibility is gained because the VAP and PMA can be made
and shipped separate from one another and connected in the
operating room upon implantation.
[0080] With reference to FIG. 12, another embodiment of a combined
VAP and PMA is shown. In this embodiment, the cap 718 defines the
fluid reservoir 754 and the mating cap 718 and base 720 pair
contain both the VAP and the physiological monitoring device. A
bezel 820 secures infusion septum 734 when inner ring 822 is
inserted into the fluid reservoir 754. The inner ring is slightly
smaller in diameter than the fluid reservoir. An inner lip 824 on
the outer ring 826 prevents the infusion septum from slipping out
of the bezel. An outer lip 828 abuts a top 830 of the fluid
reservoir 754 when the inner ring is inserted therein. An infusion
septum access port 742 provides needle access to the infusion
septum during use. An infusion catheter 728 is fluidly
interconnected to the fluid reservoir at a proximal end 730 for
communicating a therapeutic agent from the needle (not shown) to a
patient via distal end 732 during use.
[0081] An edge 746 of the cap 718 mates about a wall periphery 748
of the base 720 to secure the cap and base together. Located
between the cap and base, preferably as a hermetically sealed
module, is the electronics package 760, battery source 762,
pressure sensor 832 and PTC 736. The electronics package and
battery source are hemispherically arranged on a substrate 764 to
fit within the outer diameter portion 834 of the cap 718. Suture
holes 726 are provided to secure the complete apparatus in a
patient during use. An antenna, not shown, may also be included
with such structure.
[0082] In FIG. 13, the mating cap 718 and base 720 sandwich an
electronics package 760, battery source 762 on a substrate 764. As
input to the physiological monitoring device, a pair of ECG
electrodes 840 are mounted on a bottom surface 841 of the base 720.
The ECG electrodes monitor an ECG waveform of the patient during
use and are implanted in such a manner to achieve this. Electronic
interconnections (not shown) provide communications between the
electrodes and the electronics package. The fluid reservoir 754 is
defined by the cap 718 and is fluidly interconnected to infusion
catheter 728. A PTC 736 is coupled to the cap and to the pressure
sensor at proximal end 738.
[0083] Those skilled in the art will recognize that the present
invention may be manifested in a variety of forms other than the
specific embodiments described and contemplated herein.
Accordingly, departures in form and detail may be made without
departing from the scope and spirit of the present invention as
described in the appended claims.
* * * * *