U.S. patent application number 15/052158 was filed with the patent office on 2016-06-16 for intraatrial ventricular assist device.
The applicant listed for this patent is William E. Cohn, Oscar H. Frazier. Invention is credited to William E. Cohn, Oscar H. Frazier.
Application Number | 20160166747 15/052158 |
Document ID | / |
Family ID | 56110130 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160166747 |
Kind Code |
A1 |
Frazier; Oscar H. ; et
al. |
June 16, 2016 |
INTRAATRIAL VENTRICULAR ASSIST DEVICE
Abstract
A medical devices and methods related thereto are disclosed. In
an embodiment, the medical device including a pump configured to be
inserted within an atrium of a heart, said pump comprising an inlet
and an outlet. In addition, the pump includes a flexible outflow
conduit coupled to the outlet. The outflow conduit includes a
radially inner surface defining a throughbore, and a radially outer
surface. Further, the pump comprises a driveline configured to
conduct control and power signals between the pump and an external
device. The driveline extends through the outflow conduit between
the radially inner surface and the radially outer surface.
Inventors: |
Frazier; Oscar H.; (Houston,
TX) ; Cohn; William E.; (Bellaire, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Frazier; Oscar H.
Cohn; William E. |
Houston
Bellaire |
TX
TX |
US
US |
|
|
Family ID: |
56110130 |
Appl. No.: |
15/052158 |
Filed: |
February 24, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12243256 |
Oct 1, 2008 |
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15052158 |
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60976648 |
Oct 1, 2007 |
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Current U.S.
Class: |
600/16 |
Current CPC
Class: |
A61M 1/1034 20140204;
A61M 1/1012 20140204; A61M 1/1086 20130101; A61M 1/101 20130101;
A61M 1/1008 20140204; A61M 1/122 20140204; A61M 1/127 20130101;
A61M 1/125 20140204 |
International
Class: |
A61M 1/12 20060101
A61M001/12 |
Claims
1. A medical device comprising: a pump configured to be inserted
within an atrium of a heart, said pump comprising an inlet and an
outlet; a flexible outflow conduit coupled to the outlet, wherein
the outflow conduit includes a radially inner surface defining a
throughbore, and a radially outer surface; and a driveline
configured to conduct control and power signals between the pump
and an external device, wherein the driveline extends through the
outflow conduit between the radially inner surface and the radially
outer surface.
2. The medical device of claim 1, wherein the outflow conduit
comprises: an inner tubular layer, wherein the inner tubular layer
includes the radially inner surface; and an outer tubular layer,
wherein the outer tubular layer includes the radially outer
surface; wherein the driveline is disposed between the inner
tubular layer and the outer tubular layer.
3. The medical device of claim 2, wherein the driveline is
configured to be peeled away from the inner tubular layer.
4. The medical device of claim 2, wherein each of the inner tubular
layer and the outer tubular layer comprise electrically insulating
materials.
5. The medical device of claim 4, wherein the outer tubular layer
comprises polytetrafluoroethylene (PTFE), and the inner tubular
layer comprises expanded PTFE (ePTFE).
6. The medical device of claim 1, wherein the driveline comprises a
plurality of individual electrical conductors.
7. The medical device of claim 1, wherein the driveline comprises a
physically flexible circuit, that includes a plurality of
conductive lines etched onto a substrate.
8. A method of assisting ventricular function of a heart of a
patient comprising: inserting a pump into the heart via a vein,
wherein the pump includes an outlet that is coupled to a flexible
outflow conduit, wherein the outflow conduit includes a distal end,
a radially inner surface defining a throughbore, and a radially
outer surface, and wherein the pump further includes a driveline
coupled to the pump and extending through the outflow conduit
between the radially inner surface and the radially outer surface;
extending the outflow conduit through the vein; separating a
portion of the driveline from the outflow conduit; coupling the
portion of the driveline to an external unit; inserting the distal
end of the outflow conduit to an artery; and operating the pump
with control and power signals conducted through the driveline.
9. The method of claim 8, wherein separating the portion of the
driveline from the outflow conduit comprises peeling the portion of
the driveline away from the outflow conduit from the distal end of
the outflow conduit.
10. The method of claim 8, coupling the portion off the driveline
to an external unit comprises coupling the portion of the driveline
to at least one of a controller and a power source disposed within
the external unit.
11. The method of claim 8, further comprising perfusing oxygenated
blood into the artery through the pump and outflow conduit during
the operating of the pump.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S.
application Ser. No. 12/243,256 entitled "Intraatrial Ventricular
Assist Device," and filed Oct. 1, 2008, which further claims
priority to U.S. Provisional Application Ser. No. 60/976,648 titled
"Intraatrial Ventricular Assist Device" filed Oct. 1, 2007, the
contents of each being incorporated herein by reference in their
entireties for all purposes.
BACKGROUND
[0002] Over 50,000 people die each year because of congestive heart
failure, a condition that often cannot be treated with drug or
surgical therapies. Moreover, nearly 550,000 new patients are
diagnosed with congestive heart failure each year. For many
patients that suffer heart failure, an attractive option is heart
transplantation. The scarcity of suitable donor hearts has limited
the impact of this therapy, however. As such, recent efforts have
focused on the development of mechanical pumps to assist the
failing heart. Fortunately, great strides have been made in the
development of ventricular assist devices ("VADs"). Instead of
totally replacing heart function, a VAD augments the existing
heart's ability to pump blood. These devices have saved many
patients who would not have survived without a heart transplant.
Despite it success, current VAD technology still has much room for
improvement. Specifically, there is a need for less invasive
methods and devices that may be used to temporarily or permanently
assist a failing human heart.
BRIEF SUMMARY
[0003] Novel methods and devices for assisting ventricular function
of a heart are described herein. Embodiments of the device may be
implanted within the atrium of a heart and comprises an outflow
conduit that passes through the atrial septum. The outflow conduit
may then pass through the superior vena cava, out the subclavian
vein and be attached to a subclavian artery. Alternatively, the
device may be placed down the jugular vein. The disclosed device
foregoes the need for a pocket outside of the heart and further
does not entail cutting a hole in the ventricle. Minimally invasive
surgical techniques may be employed to implant embodiments of the
device. Other aspects and features of the disclosed methods and
devices will be described in more detail below.
[0004] Thus, embodiments comprise a combination of features and
advantages that enable it to overcome the problems of prior
devices. The foregoing has outlined rather broadly the features and
technical advantages of the disclosed embodiments in order that the
detailed description that follows may be better understood.
Additional features and advantages will be described hereinafter
that form the subject of the claims. It should be appreciated by
those skilled in the art that the conception and the specific
embodiments disclosed may be readily utilized as a basis for
modifying or designing other structures for carrying out the same
purposes. It should also be realized by those skilled in the art
that such equivalent constructions do not depart from the spirit
and scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] For a detailed description of the preferred embodiments,
reference will now be made to the accompanying drawings in
which:
[0006] FIG. 1 illustrates an embodiment of a ventricular assist
device (VAD) implanted in a heart;
[0007] FIG. 2 illustrates a close-up of an embodiment of a VAD in
the left atrium of a heart;
[0008] FIG. 3 illustrates an embodiment of a method of implanting
the disclosed VAD in a heart;
[0009] FIG. 4 illustrates a method of assisting ventricular
function of a heart of a patient;
[0010] FIG. 5 illustrates a method of assisting ventricular
function of a heart;
[0011] FIG. 6 is a perspective view that illustrates another
embodiment of a VAD;
[0012] FIG. 7 is a cross-sectional view taken along section VII-VII
in FIG. 6;
[0013] FIG. 8 is a cross-sectional view taken along section VII-VII
in FIG. 6 of another embodiment of the VAD;
[0014] FIG. 9 illustrates the VAD of FIG. 6 implanted in a
heart;
[0015] FIGS. 10 and 11 illustrate sequential, perspective views of
the driveline being peeled away from the outflow conduit of the VAD
device of FIG. 6;
[0016] FIG. 12 illustrates a box diagram of the VAD of FIG. 6 and
an external unit; and
[0017] FIG. 13 illustrates a method of assisting ventricular
function of a heart.
NOTATION AND NOMENCLATURE
[0018] Certain terms are used throughout the following description
and claims to refer to particular system components. This document
does not intend to distinguish between components that differ in
name but not function. In the following discussion and in the
claims, the terms "including" and "comprising" are used in an
open-ended fashion, and thus should be interpreted to mean
"including, but not limited to . . . . "
[0019] The term "continuous flow pump" is used to describe any pump
which utilizes a rapidly spinning impeller or similar component to
generate flow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] VADs can be right VADs ("RVADs"), left VADs ("LVADs"), or
both left and right VADs ("BiVADs") depending on which ventricle
the VAD is designed to assist. In the past, LVAD's have been based
on a pulsatile system in an effort to mimic the human heart. In
recent years, research has focused on continuous flow systems as an
alternative to the traditional pulsatile model. In a continuous
flow system, blood is continuously pumped through the body rather
than pulsing the blood rhythmically as in the human heart.
[0021] Continuous flow systems offer several advantages over
pulsatile systems. First, continuous flow pumps are generally
smaller than pulsatile pumps. Shrinking the size of artificial
heart devices will allow doctors to treat women and small children
who previously were not candidates for pulsatile LVADs. Second,
continuous flow pumps consume less energy than pulsatile systems.
This property is important for quality of life issues, allowing the
device to run on smaller batteries. Finally, continuous flow pumps
are mechanically much simpler; and have no flexible membranes or
valves resulting in substantially improved endurance.
[0022] The field of LVADs is advancing rapidly. Like any new
technology, results are improving with better device designs and
increased experience. It is now becoming increasingly clear that in
many patients, a pump with a rate 2 or 3 liters per minute may be
of value in patients in whom early (class III) heart failure is
present. By implanting such an assist device earlier in the course
of the affliction, progression to class IV may be averted.
Furthermore, in these earlier stage patients, it is quite probable
that 2 or 3 liters of blood flow per minute may be all that is
required to restore the patients to class I status.
[0023] If it is contemplated that pumps be placed in patients
earlier in the course of their illness, it is imperative that it be
done in a manner that minimizes invasiveness. As these patients are
in no immediate peril, and can be managed for a time on medical
therapy, a pump implantation procedure, if it is to be widely
accepted and practiced, must be associated with relatively little
morbidity and mortality.
[0024] To treat congestive failure and prevent, and possibly
reverse, progression of cardiac derangements, a device needs to
remove blood from the left side of the heart and deliver it into
the systemic circulation in sufficient volumes that cardiac output
is maintained or increased while left ventricular wall tension and
work is decreased. One means is to introduce a cannula through the
systemic veins, either subclavian, jugular, or femoral, and using
conventional wire skills, position the tip across the atrial septum
in the left atrium. Oxygenated blood removed from the left atrium
through this cannula can then be returned by way of a cannula or
graft attached to any systemic artery.
[0025] FIGS. 1 and 2 illustrate an embodiment of a device 100
configured specifically for limited access implantation without the
need for cardiopulmonary bypass. In an embodiment, the device
comprises a pump 111 adapted to be implanted within a heart atrium
182. Pump 111 has an inlet 113 and an outlet 115. A flexible
conduit 119 may be coupled to the pump outlet. In addition, pump
111 has an expandable attachment collar 116 for attachment to the
atrial septum 181 as shown in FIG. 2.
[0026] FIG. 1 also illustrates the configuration of an embodiment
of the device as implanted within a human heart 180. Pump 111 may
be attached to the wall or septum 181 dividing the right atrium 184
and left atrium 182 of the heart 180. Pump inlet 113 preferably is
directed toward the center of the left atrium 182. Fresh oxygenated
blood from the lungs enters the left atrium 182 and a portion may
be sucked into the pump 111. Flexible outflow conduit 119 may pass
interatrially through the septum 181 into the right atrium 184, up
the superior vena cava 186, into the subclavian 192 vein or the
ipsilateral jugular vein and through the subclavian vein or jugular
vein wall 161. Preferably, flexible outflow conduit has a diameter
no more than 9 mm and comprises a polymer of polyurethaneurea,
polytetrafluoroethylene, polyethylene, polycarbonate, silicone, or
combinations thereof. The proximal end 121 of conduit 119 may be
anastomosed to the subclavian artery 194 or other suitable artery.
Accordingly, the oxygenated blood from the left atrium 182 is
sucked into pump and forced through conduit 119 into the subclavian
artery 194 for recirculation of oxygenated blood to the body. In
relation to the superior vena cava, the flow in the conduit is
countercurrent. Preferably, the pump 111 comprises pressure
sensitive impellers. The impellers preferably comprise angled
vanes, curved vanes, flexible vanes, tapered vanes, round vanes,
propellers, open impellers, closed impellers, or any combination
thereof.
[0027] Preferably, the pump 111 comprises a continuous flow pump.
The pump 111 itself can be any one of a variety of designs,
including without limitation, centrifugal, diagonal, or axial, and
the external diameter of the pump, inclusive of the motor,
preferably fits through a narrow sheath such as without limitation,
a 24-French sheath. The pump 111 preferably provides 2-3 liters per
minute of flow. The outlet 115 of the pump 111 may be a 7 or 8 mm
graft of PTFE, Dacron, or other suitable material. The electrical
driveline (not shown) of the pump 111 will preferably run in or
closely adjacent to the outer wall of the outflow graft.
[0028] In an embodiment of a method of assisting ventricular
function of a heart, the disclosed device 100 may be implanted
within a patient using novel surgical techniques as shown in FIGS.
2 and 3. More particularly, to implant embodiments of the device, a
small incision may be made below the middle third of the clavicle.
The subclavian artery 194 is identified and exposed, preferably on
the left. A needle 141 is then introduced into the subclavian vein
192 or ipsilateral jugular vein, and a guide wire 143 is passed
into the right atrium under fluoroscopic guidance. Catheters and
surgical techniques may then be used to perform puncture of the
atrial septum 181 and create guide wire access to the left atrium
182. A sheath 145 (e.g. thin-walled split-away 24-French sheath)
may then be introduced into the left atrium 182 over a very
flexible dilator that, despite flexibility, has adequate column
stiffness to allow advancement. Fluoroscopy may be used to insure
that the distal tip 146 of the sheath 145 is across the atrial
septum 181. Alternatively, intravascular ultrasound may be used,
the two imaging techniques may be used together, or other imaging
modalities may be employed including but not limited to MRI, CT,
and ultrasound.
[0029] Once in position, the dilator is removed and the pump 111 is
placed down the sheath lumen, until the pump 111 itself is in the
left atrium 182 with the inlet 113 projecting toward the center of
the chamber. In one embodiment, a collar extending from the pump
body that is constrained by the sheath is allowed to expand in the
left atrium 182, which allows the pump 111 to be pulled back
snuggly against the interatrial septum 181, minimizing hardware in
the left atrium 182. In other embodiments, the collar is expanded
by balloon catheter inflation, by pulling a suture, or by another
mechanism.
[0030] To facilitate advancing the pump 111 down the sheath, an
obturator may be placed down the lumen of the outflow graft. The
obturator is preferably flexible to allow the pump 111 and outflow
graft or conduit 119 to successfully navigate the sheath 145, but
has sufficient column strength to allow advancement.
[0031] Once the pump 111 is in the left atrium 182, the sheath 145
is removed by splitting while using fluoroscopy to insure that the
pump 111 does not dislodge. Once the sheath has been removed
completely from the subclavian vein, the outflow graft and the pump
driveline exits through the previously created venotomy in the
ipsilateral subclavian or jugular vein. The outflow graft may be
sutured the venotomy margin to prevent venous hemorrhage around the
outflow graft. The distal end of the graft is beveled and sutured
to the subclavian artery to deliver the blood flowing from pump 111
to the systemic circulation. The driveline is tunneled through the
subcutaneous tissue to an appropriate site where it exits through
the skin, and is attached to the power supply. Preferably, the
outflow conduit passes retrograde through a lumen of systemic veins
and exits through a wall of the systemic veins to allow the outflow
conduit to be sutured, in an end-to-side fashion, to a systemic
artery.
[0032] The device 100 and technique for implantation described here
have several unique advantages. By positioning the pump 111 in the
left atrium 182, the need for a pump pocket is eliminated, thereby
reducing the likelihood of pump infection. Furthermore, the
technique described above can be done without opening the chest,
through a superficial incision, and does not require
cardiopulmonary bypass. As the pump 111 is pulled flush against the
left side of the atrial septum 181, the amount of material
protruding into the left atrium 182 is minimized. This geometric
arrangement also reduces the length of the pump blood path, which
extends from the atrial septum 181 to the left subclavian artery,
and facilitates a non-kinking lay of the outflow graft. By placing
the pump 111 directly in the left atrium 182, it is possible that
the likelihood of thrombus formation will be less due to high
velocity flow entering the pump 111. As the outflow graft will come
off the back of the pump 111 in a linear coaxial geometry,
obtaining acceptable pump and graft lie should be facilitated.
Although the patient may develop narrowing or even occlusion of the
subclavian or jugular vein, this is generally well tolerated, and
it is possible that outflow grafts of appropriate size or composed
of appropriate material on the external surface may minimize this
occurrence.
[0033] FIG. 4 illustrates a method 400 of assisting ventricular
function of a heart of a patient beginning at 402 and ending at
412. At 404, a continuous flow pump having an inlet and an outlet
is inserted into the heart via a subclavian or jugular vein. At
406, the outlet of the continuous flow pump is attached to an
atrial septum, wherein the inlet of the continuous flow pump is
directed into a heart atrium. At 408, the distal end of the outflow
conduit is attached to an artery. At 410, the pump is operated at a
volumetric rate ranging from about 2 L/min to about 3 L/min.
[0034] FIG. 5 illustrates a method 500 of assisting ventricular
function of a heart beginning at 502 and ending at 510. At 504, a
continuous flow pump is implanted within a heart atrium of a
patient, the continuous flow pump having an inlet and an outlet,
wherein the outlet of the continuous flow pump is coupled to a
flexible outflow conduit, the outflow conduit having a distal end,
wherein the outflow conduit passes through an atrial septum and
into a subclavian or jugular vein. At 506, the distal end of the
outflow conduit is attached to an artery. At 508, oxygenated blood
is perfused through a circulatory system of the patient via the
continuous flow pump.
[0035] In some embodiments, the driveline for the pump is routed
along and through the wall of the outflow conduit such that
separate routing of the driveline through the patient's body are
avoided and the number of incisions required is reduced. For
example, referring now to FIG. 6, another embodiment of a device
200 configured specifically for limited access implantation without
the need of a cardiopulmonary bypass is shown. Device 200 is
substantially similar to the device 100 previously described and
shown in FIGS. 1 and 2. As a result, like reference numerals will
be used to refer to components that are shared between devices 100,
200 and the discussion below will focus on the components and
features of device 200 that are different from device 100.
Specifically, device 200 includes pump 111 being the same as
previously described (note: expandable attachment collar 116 is not
shown on pump 111 in FIG. 6 for convenience and so as not to unduly
complicate the figure; however, collar 116 may be incorporated onto
pump 111 in system 200 in the same manner as described above for
system 100). As previously described, pump 111 includes an inlet
113 and an outlet 115 and is configured to be inserted within an
atrium of a heart (e.g., right atrium 182 of heart 180 in FIGS. 1
and 6). For example, in some embodiments pump 111 has a total
length L.sub.111 (e.g., between inlet 113 and outlet 115) of about
30 mm or less, and a maximum outer diameter D.sub.111 of about 8.5
mm or less.
[0036] In addition, system 200 includes a physically flexible
outflow conduit 219 that is coupled to outlet 115. As shown in FIG.
6, outflow conduit 219 includes a central or longitudinal axis 215,
a first or proximal end 219a, a second or distal end 219b opposite
proximal end 219a, a radially outer surface 220 extending between
ends 219a, 219b, and a radially inner surface 221 extending between
ends 219a, 219b. As used herein, the end 219a is referred to as a
"proximal" end because it is proximal to pump 111 and the end 219b
is referred to has a "distal" end because it is distal to pump 111.
Radially inner surface 221 defines a continuous throughbore or
lumen 222 extending between ends 219a, 219b such that when proximal
end 219a of outflow conduit 219 is coupled to outlet 115 of pump
111, outlet 115 is placed in fluid communication with distal end
219b via throughbore. Outflow conduit 219 includes a total length
L.sub.219 extending axially between ends 219a, 219b that preferably
ranges from 25 cm to 50 cm.
[0037] System 200 also includes a driveline 230 that is coupled to
pump 111 and is configured to route control and power signals
between pump 111 and a controller or other device (e.g., controller
284 in the external unit 280 shown in FIG. 12). In this embodiment,
driveline 230 includes a first or proximal end 230a, and a second
or distal end 230b opposite proximal end 230a. As previously
described, in this embodiment, driveline 230 extends through the
wall of the outflow conduit 219. More specifically, driveline 230
extends between radially outer surface 220 and radially inner
surface 221 of outflow conduit 219. Thus, distal end 230b of
driveline 230 is commensurate or proximate distal end 219b of
outflow conduit 219.
[0038] In addition, proximal end 230a of driveline 230 is coupled
to pump 111 at a connector 240. Connector 240 may comprise any
suitable connector (e.g., a pin connector) that is configured to
connect to a conductor (e.g., driveline 230). In this embodiment,
connector 240 is shown disposed externally to pump 111; however, in
other embodiments connector 240 is disposed internally within pump
111 and proximal end 230a of driveline 230 extends through a port
or other suitable aperture to access connector 240. While not
specifically shown, connector 240 is coupled to the internal
electronic components of pump 111. For example, connector 240 is
coupled to the motor that drives operation of pump 111 such that
coupling proximal end 230a of driveline 230 to connector 240 also
couples (e.g., electrically) driveline 230 to the motor of pump
111.
[0039] Referring now to FIG. 7, as previously described, driveline
230 is routed through the wall of outflow conduit 219, between
radially outer surface 220 and radially inner surface 221. As shown
in FIG. 7, in some embodiments, driveline 230 comprises one or more
electrical conductors 250 that extend axially and generally
parallel to one another between ends 230a, 230b and radially
between surfaces 220, 221. It should be appreciated that in other
embodiments driveline 230 may comprise only a single electrical
conductor 250 or may comprise a single bundled cable housing a
plurality of individual electrical conductors 250. In any event, in
this embodiment electrical conductors 250 each comprise an
electrically conductive material (e.g., a metal, conductive
polymer, etc.) such that each is configured to conduct electrical
signals between ends 230a, 230b. In other embodiments, conductors
250 may not be electrically conductive and may instead be
configured to conduct some other form of energy signal, such as,
for example, light signals (e.g., with driveline 230 comprising one
or more fiber optic cables), acoustic signals, etc.
[0040] In addition, in this embodiment, a subset of the conductors
250 (e.g., two) may be utilized to carry electrical power signals
between a power source (e.g., battery, capacitor, electric current
from the public utility, etc.) and pump 111 top facilitate and
drive operation of pump 111. In addition, another subset of the
conductors 250 may be utilized to carry control and informational
signals between pump 111 and a controller or other control unit
(e.g., controller 284 in the external unit 280 shown in FIG. 12).
For example, one of the conductors 250 may carry a control signal
from the controller to the pump 111 that causes the pump 111 to
produce blood from the outlet 115 at a desired rate (e.g., in a
given unit volume per unit time). As another example, one of the
conductors 250 may carry an informational signal from the pump 111
to the controller that indicates some physical condition of the
pump 111 (e.g., the rotational rate of the impeller, the internal
pressure or temperature of the pump 111, the vibration experienced
by the pump 111, etc.).
[0041] Referring now to FIG. 8, in some embodiments, driveline 230
may comprise physically flexible circuit 260 that includes a
plurality of individual conductive lines 262 etched or otherwise
formed on a substrate 261. Conductive lines 262 may be formed of
any suitable electrically conductive material such as for example a
metal or conductive polymer. Substrate 261 may comprise a
physically flexible (e.g., rollable, bendable, foldable, etc.) and
electrically insulating material such as, for example, a
polymer.
[0042] As with conductors 250 previously described, a subset of the
conductive lines 262 (e.g., two) may be utilized to carry
electrical power signals between a power source (e.g., battery,
capacitor, electric current from the public utility, etc.) and pump
111 to facilitate and drive operation of pump 111. In addition,
another subset of the conductive lines 262 may be utilized to carry
control and informational signals between pump 111 and a controller
or other control unit (e.g., controller 284 in the external unit
280 shown in FIG. 12). For example, one of the conductive lines 262
may carry a control signal from the controller to the pump 111 that
causes the pump 111 to produce blood from the outlet 115 at a
desired rate (e.g., in a given unit volume per unit time). As
another example, one of the conductive lines 262 may carry an
informational signal from the pump 111 to the controller that
indicates some physical condition of the pump 111 (e.g., the
rotational rate of the impeller, the internal pressure or
temperature of the pump 111, the vibration experienced by the pump
111, etc.).
[0043] Referring now to FIGS. 7 and 8, regardless of the type of
driveline 230 used (e.g., conductors 250 or flexible circuit 260),
driveline 230 is disposed radially between a first or inner tubular
layer 232 defined within outflow conduit 219 and a second or outer
tubular layer 236 defined within outflow conduit 219. Inner tubular
layer 232 includes radially inner surface 221 and therefore defines
throughbore 222, and outer tubular member includes radially outer
surface 220. During manufacturing of outflow conduit 219, driveline
230 is disposed along a radially outermost surface 234 of inner
layer 232, and then outer layer 236 is disposed about inner layer
232 and driveline 230 such that driveline 230 is captured (e.g.,
laminated) between layers 232, 236 as shown. Preferably each of the
inner layer 232 and outer layer 236 comprise electrically
insulating materials (e.g., polymers, elastomers, etc.). In
addition, at least inner layer 232 (and perhaps also outer layer
236 in some embodiments) comprises a fluid tight material that is
configured to restrict (if not prevent) leakage of blood or other
bodily fluids therethrough. In this embodiment, outer layer 236
comprises polytetrafluoroethylene (PTFE), and inner layer 232
comprises expanded PTFE (ePTFE).
[0044] Referring now to FIG. 9, in an embodiment of a method of
assisting ventricular function of a heart, the disclosed device 200
may be implanted within a patient in substantially the same manner
as shown and discussed for system 100. However, because driveline
230 is disposed within outflow conduit 219, driveline 230 is
carried along conduit 219 back through the subclavian vein or
jugular vein wall 161 and the original incision below the middle
third of the clavicle. Thereafter, the driveline 230 may be peeled
or otherwise separated from outflow conduit 219 from the distal end
219b, and the portion 219' of conduit 219 that is separated from
driveline 230 may be inserted into an artery (e.g., the subclavian
artery 194) as previously described above. Specifically, referring
briefly to FIGS. 10 and 11, during these operations, distal end
230b of driveline 230 may be grasped and pulled radially away from
inner tubular layer 232 and through outer tubular layer 236 such
that a portion 230' of driveline 230 may be peeled away from inner
and outer tubular layers 232, 236, respectively (note: while FIGS.
10 and 11 show driveline 230 having the flexible circuit 260, it
should be appreciated that a similar peeling operation may be
accomplished when the driveline comprises the conductors 250).
Referring back now to FIG. 9, following the partial separation of
driveline 230 from outflow conduit 219, the separated portion 230'
of driveline 230 (which includes distal end 230b) is routed outside
of the body toward an external unit 280, so that distal end 230b
may be connected or otherwise coupled to external unit 280.
[0045] Referring now to FIG. 12, a block diagram of system 200,
including external unit 280 is shown. As shown in the example of
FIG. 12, the external unit 280 includes a power source 282, a
controller 284, and a memory 286. The power source 282 may comprise
a battery (disposable or rechargeable), a capacitor, a wireless
power receiver (e.g., inductive coil, etc.), or other sources of
electrical power (e.g., power delivered from the local utility).
The power source 282 provides electrical power to pump 111 via
driveline 230 and to the other components within external device
280 (e.g., controller 284, memory 286, etc.). The controller 284
executes software provided on memory 286, and upon executing the
software on memory 286 provides the external device 280 with all of
the functionality described herein. The memory 286 may comprise
volatile storage (e.g., random access memory), non-volatile storage
(e.g., flash storage, read only memory, etc.), or combinations of
both volatile and non-volatile storage. Data consumed or produced
by the software can also be stored on memory 286. For example,
measured data (e.g., pressure, temperature, etc. from inside pump
111) may be stored on memory 286. During operations, control
signals and power signals are routed to pump 111 from controller
284 and power source 282, respectively, via driveline 230 in the
manner previously described.
[0046] FIG. 13 illustrates a method 300 of assisting ventricular
function of a heart beginning at 302 and ending at 312. At 304, a
continuous flow pump (e.g., pump 111) is implanted within a heart
atrium of a patient, the continuous flow pump having an inlet
(e.g., inlet 113) and an outlet (e.g., outlet 115), wherein the
outlet of the continuous flow pump is coupled to a flexible outflow
conduit (e.g., outflow conduit 219), the outflow conduit having a
distal end and a pump driveline (e.g., driveline 230) extending
through the wall of the outflow conduit for powering and
communicating with the pump. At 306, the driveline is separated
from the outflow conduit at the distal end of the outflow conduit
and the separated portion of the driveline is coupled to an
external unit (e.g., external unit 280) which may include a
controller (e.g., controller 284) and/or a power source (e.g.,
power source 282) for operating the pump. At 310, the distal end of
the outflow conduit, having been separated from the driveline at
306, is inserted into an artery (e.g., the subclavian artery 194).
Finally, at 310, oxygenated blood is perfused through a circulatory
system (via the artery in 306) of the patient via the continuous
flow pump.
[0047] The device 200 and technique for implantation described here
have several unique advantages, many of which are shared with
device 100 (and its associated implantation technique). For
example, as with device 100, by positioning the pump 111 in device
200 in the left atrium 182, the need for a pump pocket is
eliminated, thereby reducing the likelihood of pump infection. As
another example, as with device 100, the technique involving device
200 described above can be done without opening the chest, through
a superficial incision, and does not require cardiopulmonary
bypass. Still further, the device 200 presents several additional
advantages. For example, because driveline 230 is routed through
the wall of outflow conduit 219, no additional tunneling or
incisions need to be made to route driveline 230 to external unit
280. Therefore, the risk of infection and complications following
the installation of device 200 within a patient is minimized.
[0048] While embodiments have been shown and described,
modifications thereof can be made by one skilled in the art without
departing from the spirit and teachings of the disclosure. The
embodiments described and the examples provided herein are
exemplary only, and are not intended to be limiting. Many
variations and modifications of the embodiments disclosed herein
are possible and are within the scope of the invention.
Accordingly, the scope of protection is not limited by the
description set out above, but is only limited by the claims which
follow, that scope including all equivalents of the subject matter
of the claims.
[0049] The discussion of a reference in the Description of the
Related Art is not an admission that it is prior art, especially
any reference that may have a publication date after the priority
date of this application. The disclosures of all patents, patent
applications, and publications cited herein are hereby incorporated
herein by reference in their entirety, to the extent that they
provide exemplary, procedural, or other details supplementary to
those set forth herein.
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