Abstrict
A cuff of a wrist-mount blood pressure monitor includes an inflatable
bag to which a predetermined quantity of fluid is supplied in order
to press predetermined artery of a wrist, and a fixing member for
mounting the inflatable bag on the wrist. The fixing member has
a first half split ring-shaped fixing tool and a second half split
ring-shaped fixing tool having an approximately ring shape with
rigidity for preventing elastic deformation in a state where the
inflatable bag is inflated.
Claims
The invention claimed is:
1. A cuff of a wrist-mount blood pressure monitor comprising: an
inflatable bag to which a predetermined quantity of fluid is supplied
in order to press on an artery of a wrist; and a fixing member seperate
from the inflatable bag for mounting the inflatable bag on the wrist,
wherein the fixing member comprises a substantially ring-shaped
fixing tool having an opening end including a predetermined gap
area, holding the inflatable bag on an inner side of the fixing
tool, and having rigidity for preventing elastic deformation in
a state where the inflatable bag is inflated; and a clamp for mounting
the fixing tool on the wrist, and wherein the fixing tool comprises
first and second half split ring-shaped fixing tools connected at
one end of each of said half split ring-shaped fixing tools so as
to be turnable relatively to each other and the opening end is configured
to be positioned on a back side of the wrist, wherein free ends
of the first half split ring-shaped fixing tool and the second half
ring shaped fixing tool are each configured to come into contact
with a radius and an ulna.
2. The cuff of a wrist-mount blood pressure monitor according to
claim 1, wherein the fixing tool has an opening formed therein that
is shaped to receive the wrist without making contact with a corresponding
processus styloideus ulnae on an inner surface of said fixing tool.
3. The cuff of a wrist-mount blood pressure monitor according to
claim 1, wherein the inflatable bag is provided only on a selected
area on the inner surface of the fixing tool.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cuff of a wrist-mount blood
pressure monitor which is used in a blood pressure monitor which
is mounted on the body of a subject so as to measure blood pressure
and, more particularly, to a structure of the cuff of a wrist-mount
blood pressure monitor used in a wrist-mount blood pressure monitor
for monitoring the blood pressure on the wrist.
2. Description of the Related Art
In general, the cuff of the wrist-mount blood pressure monitor
to be used in a wrist-mount blood pressure monitor is composed of
an inflatable bag into which a fluid such as air is supplied, and
a fixing member to be mounted on a portion of a subject. After the
inflatable bag is mounted on the wrist by using the fixing member,
gas such as air is supplied to the inflatable bag, so that the artery
of the subject is pressed and blood pressure is measured at a pressuring
process or an exhaust process of the inflatable bag. As the fixing
member, a band type cuff band, a holding elastic plate disclosed
in Japanese Patent Application Laid-Open No. 9-224916 (1997) or
the like can be used.
In the prior cuff of the wrist-mount blood pressure monitor having
the above structure, however, since the fixing member is composed
of a member with elasticity from a viewpoint of facilitation or
the like of the mounting on the wrist, there arises a problem that
the fixing member stretches and is deformed according to expansion
of the inflatable bag. This problem will be explained with reference
to FIGS. 10A and 10B.
FIGS. 10A and 10B are diagrams showing a cross section of a wrist,
and FIG. 10A shows a state before the inflatable bag 51 is inflated,
and FIG. 10B shows a state where the inflatable bag 51 is inflated.
As shown in FIG. 10A, the cuff of the wrist-mount blood pressure
monitor 50, which is composed of the inflatable bag 51 and a band-type
cuff band 52 as the fixing member, is wound around the wrist 101.
As shown in FIG. 10B, the inflatable bag 51 is then inflated, so
that radial artery 104 in a vicinity of a radius 102 and ulnar artery
105 in a vicinity of an ulna 103 are pressed.
Since the cuff band 52 is, however, composed of the member with
elasticity, the inflatable bag 51 inflates to the side of the wrist
101, and the cuff band 52 stretches and deforms so that the inflatable
bag 51 inflates greatly to a direction separating from the wrist
101. At this time, as shown in FIGS. 10A and 10B, a distance (d1)
from the radius 102 to the cuff band 52 increases. That the distance
(d1) is large means that it is necessary to largely inflate the
inflatable bag 51 in order to press the wrist 101. For this reason,
a flow rate of an air pump for inflating the inflatable bag 51 should
be increased, and thus it is difficult to miniaturize the air pump.
Although a tension is generated in the inflatable bag 51 according
to its expansion, as the inflatable bag 51 inflates more largely,
the tension to be generated becomes stronger, thus deteriorating
efficiency of pressure transmission to a blood vessel wall to be
pressed. A phenomenon such that the pressure to be transmitted to
the blood vessel wall to be pressed (blood pressure of blood vessel
inner wall to be pressed) is stronger than internal pressure in
the air bag, therefore, occurs, and thus there also arises a problem
that the blood pressure cannot be measured properly.
The measuring principle of an oscillometric method is established
under the presumption that the pressure of the blood vessel inner
wall to be pressed is equal with the pressure in the inflatable
bag, and thus the pressure of the blood vessel inner wall to be
pressed is estimated to be the pressure in he pressing fluid bag.
For this reason, when the pressing force of the blood vessel to
be pressed becomes insufficient, the pressure in the inflatable
bag becomes higher than the pressure of the blood vessel inner wall
to be pressed at the time when the blood vessel to be pressed is
broken, and the blood pressure is measured high.
As the fixing member, there are a method of winding an elastic
plate harder than the cuff band around the wrist and a method of
connecting a plurality of curved covers via hinges and winding them
around the wrist. Since they, however, use an elastic member as
a material or a fastening method, the above-mentioned problems arise.
SUMMARY OF THE INVENTION
The present invention is devised in order to solve the above problems,
and its object is to provide a cuff of a wrist-mount blood pressure
monitor which adopts a fixing member for making an inflating direction
of an inflatable bag to face a wrist so as to enable an air pump
to be miniaturized and blood pressure measuring accuracy to be improved.
A cuff of a wrist-mount blood pressure monitor according to the
present invention includes: an inflatable bag to which a predetermined
quantity of fluid is supplied in order to press artery of a wrist;
and a fixing member for mounting the inflatable bag on the wrist,
wherein the fixing member includes: a substantially ring-shaped
fixing tool having an opening end including a predetermined gap
area, holding the inflatable bag on an inner side of the opening
end, and having rigidity for preventing elastic deformation in a
state where the inflatable bag is inflated; and a damper for clamping
the fixing tool on the wrist in a state where the fixing tool is
mounted on the wrist.
With this structure, even in the state where the inflatable bag
is inflated, the fixing tool is not elastically deformed, so that
the most part of pressing force caused by the expansion of the inflatable
bag contributes to pressure for pressing artery of the wrist. As
a result, since a capacity of the inflatable bag is miniaturized,
a necessary air flow rate can be reduced, so that the miniaturization
of an air pump can be realized. Reduction in an expansion quantity
of the inflatable bag suppresses tension generated in the inflatable
bag to be small, so that accurate blood pressure measurement can
be realized.
In the cuff of a wrist-mount blood pressure monitor, an inner surface
of the fixing tool preferably has a dent portion for preventing
contact with a processus styloideus ulnae. The dent portion includes
a recess which is provided on an area corresponding to the contact
portion with the processus styloideus ulnae, a through hole (opening
area), and a portion such as the recess or the through hole filled
with a soft material such as sponge. Since the fixing tool of the
present invention is not elastically deformed, when the fixing tool
is mounted on the wrist, the fixing tool comes in contact with the
processus styloideus ulnae, and thus it is considered that the processus
styloideus ulnae aches. The dent portion for avoiding the contact
with the processus styloideus ulnae is, therefore, provided, so
that the fixing tool is avoided contacting with the processus styloideus
ulnae, and the cuff of the wrist-mount blood pressure monitor can
be mounted on the wrist comfortably. The processus styloideus ulnae
is fitted into the dent portion, so that locating of the cuff of
the wrist-mount blood pressure monitor with respect to the wrist
can be realized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a structure of a cuff of a wrist-mount
blood pressure monitor 10 according to the first embodiment of the
present invention.
FIG. 2 is a whole perspective view showing only a structure of
a fixing member 10A of the cuff of the wrist-mount blood pressure
monitor 10 according to the first embodiment of the present invention.
FIGS. 3A and 3B are diagrams showing a state where the cuff of
the wrist-mount blood pressure monitor 10 is mounted on a wrist
101 according to the first embodiment of the present invention.
FIG. 4 is a whole perspective view showing only a structure of
the fixing member 10B of the cuff of the wrist-mount blood pressure
monitor according to the second embodiment of the present invention.
FIG. 5 is a whole perspective view showing only the structure of
the fixing member 10C of the cuff of the wrist-mount blood pressure
monitor according to the third embodiment of the present invention.
FIG. 6 is a whole perspective view showing only the structure of
the fixing member 10D of the cuff of the wrist-mount blood pressure
monitor according to the fourth embodiment of the present invention.
FIG. 7 is a whole perspective view showing a structure in which
a main body portion 30 of the wrist-mount blood pressure monitor
is mounted on the fixing member 10B of the second embodiment according
to the fifth embodiment of the present invention.
FIG. 8 is a sectional view showing a structure of the cuff of the
wrist-mount blood pressure monitor 20 according to the sixth embodiment
of the present invention.
FIGS. 9A and 9B are diagrams showing a state where the cuff of
the wrist-mount blood pressure monitor 20 is mounted on the wrist
101 according to the sixth embodiment of the present invention.
FIGS. 10A and 10B are diagrams showing a state where the cuff for
the wrist-mount blood pressure monitor 50 is mounted on the wrist
101 in a prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of a cuff of a wrist-mount blood pressure monitor
of the present invention will be explained below with reference
to the drawings.
First Embodiment
(Structure of the Cuff of the Wrist-Mount Blood Pressure Monitor
10)
A structure of the cuff of the wrist-mount blood pressure monitor
10 according to the embodiment of the present invention is explained
with reference to FIGS. 1 and 2. FIG. 1 is a sectional view showing
the structure of the cuff of the wrist-mount blood pressure monitor
10, and FIG. 2 is a whole perspective view showing only a structure
of a fixing member 10A of the cuff of the wrist-mount blood pressure
monitor 10.
With reference to these drawings, the cuff of the wrist-mount blood
pressure monitor 10 has an inflatable bag 16 to which a predetermined
quantity of fluid is supplied in order to press predetermined artery
of a wrist, and the fixing member 10A for mounting the inflatable
bag 16 on the wrist. The fixing member 10A has a first half split
ring-shaped fixing tool 11 and a second half split ring-shaped fixing
tool 12 having an approximately ring shape which are not elastically
deformed in a state where the inflatable bag 16 is inflated. As
a material of the first half split ring-shaped fixing tool 11 and
the second half split ring-shaped fixing tool 12, acrylic resin,
ABS resin or the other thermoplastic, metal or the like with a thickness
of about 1 mm to 20 mm is used.
One end of the first half split ring-shaped fixing tool 11 has
a convex area 11a, and one end of the second half split ring-shaped
fixing tool 12 has a dent portion 12a for receiving the convex area
11a so that they are connected by a hinge 13 in a turnable state.
The other end of the first half split ring-shaped fixing tool 11
has a rail 14 with a slit 14s and the other end of the second half
split ring-shaped fixing tool 12 has a clamping screw 15 which slides
along the slit 14a and fixing the sliding with respect to the rail
14 due to clamping as a damper for clamping the fixing member 10A
to the wrist in the state where the fixing member 10A is mounted
on the wrist. The rail 14 is also prevented from elastically deforming.
An opening end 17 composed of a predetermined gap area is provided
on the side at the other ends of the first half split ring-shaped
fixing tool 11 and the second half split ring-shaped fixing tool
12 from a viewpoint of correspondence to wrist having various thickness.
(Mounting State and Working Effect)
FIGS. 3A and 3B show a state where the cuff of the wrist-mount
blood pressure monitor 10 having the above structure is mounted
on the wrist 101. FIG. 3A shows the state before the inflatable
bag 16 inflates, and FIG. 3B shows the state where the inflatable
bag 16 inflates.
When the inflatable bag 16 is inflated, a force is applied from
the inflatable bag 16 so that the first half split ring-shaped fixing
tool 11 and the second half split ring-shaped fixing tool 12 are
widened outward in the cuff of the wrist-mount blood pressure monitor
10. The first half split ring-shaped fixing tool 11 and the second
half split ring-shaped fixing tool 12 are not, however, deformed,
and the ends of the first half split ring-shaped fixing tool 11
and the second half split ring-shaped fixing tool 12 come in contact
with a radius 102 and an ulna 103 so as to holds the wrist 101 sufficiently
(in FIG. 3B, areas surrounded by X1 and X2). As a result, as shown
in FIGS. 3A and 3B, a distance (d2) between the radius 102 and the
fixing tool can be smaller than the distance (d1) shown in FIGS.
10A and 10B.
That is to say, the most part of the pressing force generated by
the expansion of the inflatable bag 16 contributes to pressure for
pressing the artery of the wrist 101. As a result, the capacity
of the inflatable bag 16 is miniaturized, and thus a necessary air
flow rate is reduced, so that miniaturization of an air pump can
be realized. The miniaturization of the inflatable bag 16 suppresses
the tension generated in the inflatable bag 16 to be small, so that
the accurate measurement of the blood pressure can be realized.
The cuff of the wrist-mount blood pressure monitor 10 can be mounted
in the state where the first half split ring-shaped fixing tool
11 and the second half split ring-shaped fixing tool 12 are widened
largely, so that convenience of the mounting of the cuff of the
wrist-mount blood pressure monitor 10 on the wrist 101 can be improved.
Since the first half split ring-shaped fixing tool 11 and the second
half split ring-shaped fixing tool 12 can be turned each other,
they can easily cope with the thickness of the wrist.
Second Embodiment
Since the characteristics of the cuff of the wrist-mount blood
pressure monitor in this embodiment is the structure of the fixing
member, only the structure of the fixing member will be explained.
The other parts of the structure are the same as the structure of
the cuff of the wrist-mount blood pressure monitor 10 in the first
embodiment. The structure of the fixing member 10B is explained
with reference to FIG. 4. FIG. 4 is a whole perspective view showing
the structure of the fixing member 10B.
(Structure of the Fixing Member 10B)
When the fixing member 10B in this embodiment is compared with
the structure of the fixing member 10A in the first embodiment,
a predetermined area of the first half split ring-shaped fixing
tool 11 has an opening area 11h for avoiding contact with a processus
styloideus ulnae of the wrist. The other parts of the structure
are the same as the structure of the fixing member 10A.
(Working Effect)
The cuff of the wrist-mount blood pressure monitor using the fixing
member 10B in the present embodiment can also produce the working
effect similar to that in the first embodiment. Since the first
half split ring-shaped fixing tool 11 of this embodiment is not
elastically deformed, when the first half split ring-shaped fixing
tool 11 is mounted on the wrist 101, the first half split ring-shaped
fixing tool 11 comes in contact with the processus styloideus ulnae,
and thus it is considered that the processus styloideus ulnae aches.
When the opening area 11h for avoiding the contact with the processus
styloideus ulnae is, therefore, provided, the first half split ring-shaped
fixing tool 11 avoids contacting with the processus styloideus ulnae,
so that the cuff of the wrist-mount blood pressure monitor can be
mounted on the wrist 101 comfortably. When the processus styloideus
ulnae is fitted into the opening area 11h, locating of the cuff
of the wrist-mount pressure blood monitor with respect to the wrist
101 can be also realized.
In this embodiment, the opening area 11h is provided on the first
half split ring-shaped fixing tool 11, but such an area is not limited
to the opening area, and a dent portion for avoiding the contact
with the processus styloideus ulnae may be provided on an inner
surface of the first half split ring-shaped fixing tool 11.
Third Embodiment
Since the characteristic of the cuff of the wrist-mount blood pressure
monitor in this embodiment is the structure of the fixing member,
only the structure of the fixing member will be explained. The other
parts of the structure are the same as the structure of the cuff
of the wrist-mount blood pressure monitor 10 in the first embodiment.
The structure of the fixing member 10C will be explained below with
reference to FIG. 5. FIG. 5 is a whole perspective view showing
the structure of the fixing member 10C.
(Structure of the Fixing Member 10C)
When the fixing member 10C in this embodiment is compared with
the structure of the fixing member 10A in the first embodiment,
the connected position of the first half split ring-shaped fixing
tool 11 and the second half split ring-shaped fixing tool 12 by
means of the hinge 13 shifts from an axial center C. The other parts
of the structure are the same as the structure of the fixing member
10A.
(Working Effect)
Also the cuff of the wrist-mount blood pressure monitor using the
fixing member 10C in this embodiment can produce the working effect
similar to that of the first embodiment.
Fourth Embodiment
Since the characteristic of the cuff of the wrist-mount blood pressure
monitor in this embodiment is the structure of the fixing member,
only the structure of the fixing member will be explained. The other
parts of the structure are the same as the structure of the cuff
of the wrist-mount blood pressure monitor 10 in the first embodiment.
The structure of the fixing member 10D will be explained below with
reference to FIG. 6. FIG. 6 is a whole perspective view showing
the structure of the fixing member 10D.
(Structure of the Fixing Member 10D)
When the fixing member 10D in this embodiment is compared with
the structure of the fixing member 10A in the first embodiment,
a hinge 33 containing a spring member, which connects the first
half split ring-shaped fixing tool 11 and the second half split
ring-shaped fixing tool 12, is used instead of the rail 14 and the
clamping screw 15 as the clamper for clamping the fixing member
10D to the wrist (to a direction of an arrow A in the drawing) in
a state where the fixing member 10D is mounted on the wrist. The
other parts of the structure are the same as the structure of the
fixing member 10A.
(Working Effect)
Also the cuff of the wrist-mount blood pressure monitor using the
fixing member 10D in this embodiment can produce the working effect
similar to that of the first embodiment. In this embodiment, when
the gap between the first half split ring-shaped fixing tool 11
and the second half split ring-shaped fixing tool 12 is tried to
be widened, the spring member in the hinge 33 always applies an
energizing force to a a direction in which the first half split
ring-shaped fixing tool 11 and the second half split ring-shaped
fixing too 112 are closed (to the direction A in the drawing). As
a result, the mounting work for mounting the fixing member 10D on
the wrist can be facilitated.
Fifth Embodiment
In this embodiment, as shown in FIG. 7, a main body section 30
of the wrist-mount blood pressure monitor is mounted onto the fixing
tool 10B in the second embodiment.
In the cuff of the wrist-mount blood pressure monitor 10 in the
second embodiment, since the capacity of the inflatable bag 16 can
be miniaturized, the necessary air flow rate can be reduced, so
that the miniaturization of the air pump can be realized. As a result,
as shown in FIG. 7, the main body section 30 can be thinned, and
thus the entire wrist-mount blood pressure monitor to which the
cuff of the wrist-mount blood pressure monitor 10 is applied can
be miniaturized.
The present invention can be applied not only to the fixing member
10B of the second embodiment but also to the fixing member 10A of
the first embodiment and the fixing member 10C of the third embodiment.
Sixth Embodiment
The characteristic of the cuff of the wrist-mount blood pressure
monitor in this embodiment is arrangement of the inflatable bag.
In the cuff of the wrist-mount blood pressure monitor 10 in the
first through fifth embodiments, as shown in FIG. 1, the inflatable
bag 16 is arranged over an entire area of the inner surface of the
fixing member 10A. In the cuff of the wrist-mount blood pressure
monitor 20 in this embodiment, however, as shown in FIG. 8, the
inflatable bag 26 is provided only on a selected area of the inner
surface of the fixing member 10A.
FIGS. 9A and 9B show a state where the cuff of the wrist-mount
blood pressure monitor 20 having the above structure is mounted
on the wrist 101. FIG. 9A shows the state before the inflatable
bag 26 inflates, and FIG. 9B shows the state where the inflatable
bag 26 inflates.
In this embodiment, as mentioned above, the most part of the pressing
force caused by the expansion of the inflatable bag can contribute
to the pressing force of artery. As shown in the drawing, therefore,
when only the radial artery 104 is tried to be pressed, the inflatable
bag 26 is provided only on the selected area corresponding to the
radial artery 104, so that only the radial artery 104 can be pressed
securely. As a result, even in the case where the extremely small
pressing fluid bag 26 presses locally, the blood pressure can be
measured accurately. The necessary air flow rate for the inflatable
bag 26 can be further reduced, so that the miniaturization of the
air pump can be realized. The above embodiments explain the case
in which the first half split ring-shaped fixing tool 11 and the
second half split ring-shaped fixing tool 12 are used, but the similar
working effect can be produced also by one unit type ring-shaped
member having an opening area which overall has the similar shape
and can allow the wrist to pass. The present invention is not limited
to the two split structure composed of the first half split ring-shaped
fixing tool 11 and the second half split ring-shaped fixing tool
12, and can adopt also a two or more split structure.
The above disclosed embodiments are, therefore, examples at all
points and does not become the basis of limiting interpretation.
The technical scope of the present invention is not, therefore,
interpreted only by the above embodiments but is defined based on
the claims. The present invention includes all modifications in
meaning equivalent to the claims and within the scope of the claims.
According to the cuff of the wrist-mount blood pressure monitor
based on the present invention, the miniaturization of the air pump
can be realized. As a result, the whole wrist-mount blood pressure
monitor to which the cuff of the wrist-mount blood pressure monitor
is applied can be miniaturized. When the expansion quantity of the
inflatable bag is reduced, the tension to be generated in the inflatable
bag is suppressed to be small, so that the accurate measurement
of the blood pressure can be also realized. |