DESCRIPTION
TITLE OF INVENTION
Blood Reservoir for Newborn
5 TECHNICAL FIELD
The present invention relates to a blood reservoir for a newborn, which is used
in heart surgery employing an artificial heart and lung of a newborn. While a
"newborn" usually refers to an infant in the first 28 days after birth, the term as used
herein also encompasses an infant after 28 days of birth. The term "newborn" as used
10 herein refers generally to children on which appropriate heart surgery can be performed
by using the "blood reservoir for a newborn" disclosed herein.
BACKGROUNDART
An artificial heart-lung machine is used in conventional heart surgery. The
artificial heart-lung machine mainly consists of a blood reservoir, a blood pump, a heat
15 exchanger, a blood circuit, an oxygenator, and the like. In such an artificial heart-lung
machine, first, blood withdrawn from the veins of a patient (venous blood) and blood
aspirated from a surgical field (aspirated blood) are delivered into the blood reservoir,
and temporarily stored in the blood reservoir.
The blood temporarily stored in the blood reservoir is pumped into the heat
20 exchanger by the blood pump, and the temperature of the blood is adjusted in the heart
exchanger. Further, in the oxygenator, gas exchange (removal of carbon dioxide and
addition of oxygen) is carried out on the temperature-adjusted blood. Finally, this
blood is returned to the body of the patient as arterial blood.
Such an artificial heart-lung machine temporarily takes over the function of a
25 heart and lungs during heart surgery. In the artificial heart-lung machine, therefore,
foreign materials, bubbles and the like which have been mixed into the blood during the
surgery need to be removed before the blood is returned to the patient. For example,
Japanese Patent Laying-Open No. 2010-88736 (PTD 1) discloses a blood reservoir
(blood reservoir including a cardiotomy reservoir) capable of simultaneously removing
bubbles and foreign materials such as bone fragments and soft tissue fragments from
blood.
CITATION LIST
PATENT DOCUMENT
5 PTD 1 : Japanese Patent Laying-Open No. 20 10-88736
SUMMARY OF INVENTION
TECHNICAL PROBLEM
When performing heart surgery on a newborn, newborns and infants have a
lower resistance than adults. Thus, it is not preferable to mix blood aspirated from a
10 surgical field (aspirated blood) with venous blood in a blood reservoir and return the
blood to the body of a newborn, as in the case of an adult. Usually, the aspirated
blood is purified by a blood purifier before being returned to the body of a newborn.
However, since the amount of blood in the heart of a newborn is smaller than
that of an adult (about 200 ml to 300 ml for a newborn (weighing 2000 g to 3000 g)),
15 autologous blood may be needed during surgery. In such a case, due to the nature of
the emergency, the aspirated blood inevitably needs to be returned to the body of a
newborn. In this case, too, foreign materials, bubbles and the like which have been
mixed into the blood during surgery need to be removed from the aspirated blood.
Accordingly, this invention has been made in view of the problem described
20 above, and provides a blood reservoir for a newborn which can be suitably used in
heart surgery employing an artificial heart and lung of a newborn.
SOLUTION TO PROBLEM
A blood reservoir for a newborn based on this invention is a blood reservoir for
a newborn used in heart surgery employing an artificial heart and lung of a newborn,
25 including a first chamber provided with a blood outlet port in a lower portion thereof,
to store venous blood withdrawn from a vein of a newborn, a second chamber provided
integrally with and above the first chamber and partitioned from the first chamber, to
store aspirated blood aspirated from a surgical field of the heart of the newborn, a
communication path to deliver the aspirated blood stored in the second chamber toward
the first chamber, and a path openinglclosing member to open or close the
communication path.
A venous blood inlet port into which the venous blood withdrawn from the vein
of the newborn is flowed is provided in the second chamber, an inner tube path having
5 one end coupled to the venous blood inlet port and an other end reaching a region in the
vicinity of the blood outlet port of the first chamber is provided within the second
chamber and the first chamber, a first filter in the form of a tube having an opened top
and a closed bottom, to contain the other end side of the inner tube path therein and to
filter the venous blood flowing out of the other end of inner tube path, is provided
10 within the first chamber, a second filter to filter the aspirated blood introduced into the
second chamber is provided within the second chamber, the communication path has a
discharge opening located within the first filter, and an aspirated blood transfer member,
on which the aspirated blood contacts when discharged from the discharge opening,
and which passes the aspirated blood toward the blood outlet port therebelow, is
15 provided between the discharge opening and the first filter.
In another embodiment, the aspirated blood transfer member is provided at an
angle within the first filter, and the discharge opening is provided to face an upper side
of the aspirated blood transfer member.
In another embodiment, the inner tube path includes a first inner tube path and a
20 second inner tube path arranged in parallel, and the aspirated blood discharged from the
discharge opening passes between the first inner tube path and the second inner tube
path.
In another embodiment, the first chamber and the second chamber are formed of
a translucent member such that an amount of blood stored therein can be visually
25 recognized from outside.
In another embodiment, the path openinglclosing member is a cock to open the
communication path by being pulled up and close the communication path by being
pulled down.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the blood reservoir for a newborn based on this invention, a blood
reservoir for a newborn which can be suitably used in heart surgery employing an
artificial heart and lung of a newborn can be provided.
BRIEF DESCRIPTION OF DRAWINGS
5 Fig. 1 is a perspective view showing an overall structure of a blood reservoir for
a newborn.
Fig. 2 is a side view showing the overall structure of the blood reservoir for a
newborn.
Fig. 3 is a plan view showing the overall structure of the blood reservoir for a
10 newborn.
Fig. 4 is a vertical sectional view showing the overall structure of the blood
reservoir for a newborn.
Fig. 5 is a sectional view taken along line V-V in a direction or arrows in Fig. 4.
Fig. 6 is a fragmentary enlarged sectional view of Fig. 4.
15 DESCRIPTION OF EMBODIMENTS
An embodiment of a blood reservoir for a newborn based on the present
invention will be described below with reference to the drawings. When a number, an
amount or the like is mentioned in the embodiment described below, the scope of the
present invention is not necessarily limited to the number, the amount or the like unless
20 otherwise specified. In addition, it is originally intended to combine configurations
represented in each embodiment as appropriate.
As used herein, venous blood refers to blood withdrawn from a blood vessel of
a newborn (patient) through a cannula, and aspirated blood refers to blood aspirated
from a surgical field, which is inside or outside the heart (vented blood and suctioned
25 blood). In addition, as used herein, foreign materials refer to substances other than
blood which are likely to be included in the aspirated blood such as fat globules, soft
tissue fragments, bone fragments, denatured proteins, and aggregates.
Referring to Figs. 1 to 3, an external structure of a blood reservoir for a
newborn 1 is described. Fig. 1 is a perspective view showing an overall structure of
blood reservoir for a newborn 1, Fig. 2 is a side view showing the overall structure of
blood reservoir for a newborn 1, and Fig. 3 is a plan view showing the overall structure
of blood reservoir for a newborn 1.
Blood reservoir for a newborn 1 is used in heart surgery employing an artificial
5 heart and lung of a newborn. A first chamber (venous blood storage unit) 100 is
provided in a lower portion, and a second chamber (cardiotomy blood storage unit) 200
is provided above this first chamber 100.
Venous blood B 10 withdrawn from a vein of a newborn is stored in first
chamber 100. A blood outlet port 100P to drain stored blood B30 is provided in a
10 lower portion. A coupling opening 150 which can be coupled to an artificial heartlung
machine is also provided.
Second chamber 200 is provided integrally with first chamber 100, and is
internally partitioned from first chamber 100. Aspirated blood B20 aspirated from the
surgical field of the heart of a newborn is stored in second chamber 200.
15 First chamber 100 and second chamber 200 are made of a resin molded article.
First chamber 100 and second chamber 200 may be formed of a translucent member so
that the amount of blood stored therein and the state of blood therein can be visually
recognized from outside. Examples of the translucent member include polycarbonate,
acrylic resin, polystyrene, and polyvinyl chloride.
20 A venous blood inlet port 2 10P into which venous blood B 10 withdrawn from a
vein of a newborn is flowed, and an aspirated blood inlet port 220P into which
aspirated blood B20 aspirated from the surgical field of the heart of the newborn is
flowed are provided in an upper portion of second chamber 200.
Venous blood inlet port 210P is internally coupled to an inner tube path 500 as
25 will be described later, and venous blood B 10 flowing in from venous blood inlet port
2 10P is delivered into first chamber 100 through inner tube path 500.
Aspirated blood inlet port 220P includes a first aspirated blood inlet port 221P,
a second aspirated blood inlet port 222P, a third aspirated blood inlet port 223P, and a
fourth aspirated blood inlet port 224P. They are herein collectively referred to as
aspirated blood inlet port 220P.
An upper portion of a cock 300 serving as a path openinglclosing member to
open or close a communication path 400 to be described later is exposed at second
chamber 200. Cock 300 has a body portion 3 10 and a lever portion 320, as shown in
5 Fig. 3, where lever portion 320 is pivoted to move body portion 3 10 up and down.
When lever portion 320 is located at a "close" position, body portion 3 10 is
pulled down and communication path 400 is closed. When lever portion 320 is
pivoted to an "open" position, on the other hand, body portion 3 10 is pulled up and
communication path 400 is opened.
10 Referring now to Figs. 4 to 6, an internal structure of blood reservoir for a
newborn 1 is described. Fig. 4 is a vertical sectional view showing the overall
structure of blood reservoir for a newborn 1, Fig. 5 is a sectional view taken along line
V-V in a direction or arrows in Fig. 4, and Fig. 6 is a fragmentary enlarged sectional
view of Fig. 4.
15 First chamber 100 and second chamber 200 are partitioned from each other by a
dividing wall 350. An aspirated blood antifoaming filter 210 having a cylindrical
shape, and a foreign material removing filter 220 provided to surround the outer side of
this aspirated blood antifoaming filter 210 are provided at a position below aspirated
blood inlet port 220P of first chamber 100. Aspirated blood antifoaming filter 2 10
20 and foreign material removing filter 220 form a second filter to filter aspirated blood
B20.
Urethane foam is used, for example, for aspirated blood antifoaming filter 210.
Further, an antifoaming agent which performs defoaming upon contact with bubbles,
for example, silicone, may be applied to this urethane foam. Thereby, bubbles
25 included in the aspirated blood burst by the antifoaming agent when the aspirated blood
makes contact with aspirated blood antifoaming filter 210.
A mesh cloth (screen mesh) may be used for foreign material removing filter
220. It is preferable that the mesh cloth have a pore size, of about 20 to 40 pm.
Aspirated blood B20 introduced into second chamber 200 from aspirated blood
inlet port 220P passes through aspirated blood antifoaming filter 210 and foreign
material removing filter 220 to communication path 400, and is temporarily stored in
second chamber 200.
Communication path 400 consists of an accumulation portion 4 10 formed by
5 shaping a portion of dividing wall 350 like a funnel, and a discharge tube path 420
provided below this accumulation portion 410 and extending downward. A discharge
opening 420a extending at an angle is provided in a lower end of discharge tube path
420. With discharge opening 420a being thus inclined with respect to discharge tube
path 420, a flow rate of aspirated blood B20 dropping down discharge tube path 420
10 can be reduced.
An opening 4 1 Oh is provided in a lower end of accumulation portion 4 10.
This opening 410h can be opened or closed by an O-ring 3 lor provided at a lower end
of body portion 3 10 of cock 300. In the state shown in Fig. 4, opening 410h is closed
by O-ring 3 lor, with body portion 3 10 being pulled down. Thus, aspirated blood B20
15 is temporarily stored in accumulation portion 4 10.
In the state shown in Fig. 6, opening 410h is opened, with body portion 3 10
being pulled up. Thus, aspirated blood B20 in accumulation portion 4 10 is released
through discharge tube path 420 and discharge opening 420a toward second chamber
200.
As shown in Fig. 4, venous blood inlet port 210P is coupled to inner tube path
500. This inner tube path 500 penetrates through dividing wall 350, and has an other
end (lower end) reaching a region in the vicinity of blood outlet port 100P of first
chamber 100. As shown in Fig. 5, in this embodiment, inner tube path 500 includes a
first inner tube path 5 10 and a second inner tube path 520 arranged in parallel.
25 A first filter 110 in the form of a tube having an opened top and a closed bottom,
to contain the other end side of inner tube path 500 therein and to filter the venous
blood flowing out of the other end of inner tube path 500, is provided within first
chamber 100. First filter 1 10 has a frame structure 1 1 Of, with a filter member 1 log
provided between portions of frame structure 1 10f. A mesh cloth (screen mesh) may
be used for filter member 1 log. It is preferable that the mesh cloth have a pore size of
about 20 to 40 pm.
Further, an aspirated blood transfer member 120, on which aspirated blood B20
contacts when discharged from discharge opening 420a, and which passes aspirated
5 blood B20 toward blood outlet port 100P therebelow, is provided between discharge
opening 420a and first filter 110.
Aspirated blood transfer member 120 is provided at an angle with respect to a
vertical direction along frame structure 110c and discharge opening 420a is provided to
face an upper side of aspirated blood transfer member 120.
10 As shown in Fig. 5, discharge tube path 420 is provided such that aspirated
blood B20 discharged from discharge opening 420a passes between first inner tube
path 5 10 and second inner tube path 520. Thereby, aspirated blood B20 can be passed
toward blood outlet port 100P through the use of the entire surface of aspirated blood
transfer member 120.
15 Aspirated blood transfer member 120 is a member to suppress the flow rate of
aspirated blood B20 delivered from discharge opening 420a, and guide aspirated blood
B20 toward blood outlet port 100P without causing bubbles in aspirated blood B20.
Aspirated blood transfer member 120 is formed as a plate expanding in upward,
downward, left and right directions, and is made of a foaming material compressed in a
20 thickness direction.
A material having a density D corresponding to an inclination angle a of frame
structure 1 lOf is used for aspirated blood transfer member 120. For example,
aspirated blood transfer member 120 may be made of a material having a density D
within a range of from 0.12 g/cm3 to 0.16 g/cm3. Herein, aspirated blood transfer
25 member 120 is made of a material having a density D of 0.13 g/cm3.
Urethane foam is used, for example, for aspirated blood transfer member 120.
Specifically, compressed urethane foam obtained by compressing urethane foam is
used for aspirated blood transfer member 120. The compressed urethane foam used
herein is formed by compressing urethane foam having a thickness of 10 mm to a
thickness of 2 mm.
For example, compressing a commercially available urethane foam having a
density of 26 to 30 kg/m3 as described above results in a compressed urethane foam
having a density of 0.13 to 0.15 g/cm3.
5 Generally, as density D of the material for aspirated blood transfer member 120
increases, aspirated blood transfer member 120 has less voids. When density D of the
material for aspirated blood transfer member 120 increases, therefore, the aspirated
blood is less likely to permeate through aspirated blood transfer member 120. That is,
when density D of the material for aspirated blood transfer member 120 increases, the
10 aspirated blood is more likely to travel on the surface of aspirated blood transfer
member 120 without permeating through aspirated blood transfer member 120.
Thus, when density D of the material for aspirated blood transfer member 120
increases, the speed at which the aspirated blood travels through aspirated blood
transfer member 120 tends to increase. For such reasons, it is desirable to dispose
15 aspirated blood transfer member 120 such that inclination angle a of aspirated blood
transfer member 120 becomes gentler as density D of the material for aspirated blood
transfer member 120 increases. It is noted that inclination angle a refers to an angle
formed between a horizontal surface and aspirated blood transfer member 120.
Fig. 6 shows an example where density D of aspirated blood transfer member
20 120 is 0.13 g/cm3. However, if inclination angle a of frame structure 11Of is changed,
it is desirable to change density D of the material for the reasons as described above.
When inclination angle a is greater than or equal to 70 degrees, for example, it
is desirable to use a porous material having a density D within a range of from 0.02
g/cm3 to 0.05 g/cm3. When inclination angle a is greater than or equal to 65 degrees
25 and less than 70 degrees, it is desirable to use a porous material having a density D
within a range of from 0.05 g/cm3 to 0.20 g/cm3. Further, when inclination angle a is
less than 65 degrees, it is desirable to use a porous material having a density D within a
range of from 0.20 g/cm3 to 0.40 g/cm3.
As described above, according to blood reservoir for a newborn 1 in this
embodiment, even if autologous blood is needed during heart surgery employing an
artificial heart and lung of a newborn, healthcare workers such as a clinical engineer, a
nurse, or a doctor can provide the newborn with aspirated blood from which foreign
materials, bubbles and the like have been removed, while keeping track of the amount
5 of blood withdrawn from the newborn, that is, the amount of blood stored. As such, a
blood reservoir for a newborn which can be suitably used in heart surgery employing
an artificial heart and lung of a newborn can be provided.
It should be understood that the embodiments disclosed herein are illustrative
and non-restrictive in every respect. The scope of the present invention is defined by
10 the terms of the claims, rather than the description above, and is intended to include any
modifications within the scope and meaning equivalent to the terms of the claims.
REFERENCE SIGNS LIST
1 blood reservoir for newborn; 100 first chamber; 1 OOP blood outlet port; 1 10
first filter; 110f frame structure; 1 log filter member; 120 aspirated blood transfer
15 member; 150 coupling opening; 200 second chamber; 2 10 antifoaming filter; 2 10P
venous blood inlet port; 220 foreign material removing filter; 220P aspirated blood
inlet port; 221P first aspirated blood inlet port; 222P second aspirated blood inlet port;
223P third aspirated blood inlet port; 224P fourth aspirated blood inlet port; 300 cock;
3 10 body portion; 3 1 Or O-ring; 320 lever portion; 3 50 dividing wall; 400
20 communication path; 4 10 accumulation portion; 4 1 Oh opening; 420 discharge tube
path; 420a discharge opening; 500 inner tube path; 5 10 first inner tube path; 520
second inner tube path; B10 venous blood; B20 aspirated blood; B30 stored blood.

CLAIMS
1. A blood reservoir for a newborn used in heart surgery employing an
artificial heart and lung of a newborn, comprising:
5 a first chamber provided with a blood outlet port in a lower portion thereof, to
store venous blood withdrawn from a vein of a newborn;
a second chamber provided integrally with and above the first chamber and
partitioned from the first chamber, to store aspirated blood aspirated from a surgical
field of the heart of the newborn;
10 a communication path to deliver the aspirated blood stored in the second
chamber toward the first chamber; and
a path openinglclosing member to open or close the communication path,
a venous blood inlet port into which the venous blood withdrawn from the vein
of the newborn is flowed being provided in the second chamber,
15 an inner tube path having one end coupled to the venous blood inlet port and an
other end reaching a region in the vicinity of the blood outlet port of the first chamber
being provided within the second chamber and the first chamber,
a first filter in the form of a tube having an opened top and a closed bottom, to
contain the other end side of the inner tube path therein and to filter the venous blood
20 flowing out of the other end of inner tube path, being provided within the first chamber,
a second filter to filter the aspirated blood introduced into the second chamber
being provided within the second chamber,
the communication path having a discharge opening located within the first
filter, and
25 an aspirated blood transfer member, on which the aspirated blood contacts when
discharged from the discharge opening, and which passes the aspirated blood toward
the blood outlet port therebelow, being provided between the discharge opening and the
first filter.2. The blood reservoir for a newborn according to claim 1, wherein
the aspirated blood transfer member is provided at an angle within the first filter,
and
the discharge opening is provided to face an upper side of the aspirated blood
transfer member
3. The blood reservoir for a newborn according to claim 1 or 2, wherein
the inner tube path includes a first inner tube path and a second inner tube path
arranged in parallel, and
the aspirated blood discharged from the discharge opening passes between the
first inner tube path and the second inner tube path.
4. The blood reservoir for a newborn according to any one of claims 1 to 3,
wherein
the first chamber and the second chamber are formed of a translucent member
such that an amount of blood stored therein can be visually recognized from outside.
5. The blood reservoir for a newborn according to any one of claims 1 to 4,
wherein
the path opening/closing member is a cock to open the communication path by
being pulled up and close the communication path by being pulled down.