U.S. patent number 3,626,929 [Application Number 04/843,016] was granted by the patent office on 1971-12-14 for apparatus for obtaining a percutaneous and digital blood sample.
This patent grant is currently assigned to Micromedic Systems, Inc.. Invention is credited to Georges Revillet, Manuel Sanz.
United States Patent |
3,626,929 |
Sanz , et al. |
December 14, 1971 |
**Please see images for:
( Certificate of Correction ) ** |
APPARATUS FOR OBTAINING A PERCUTANEOUS AND DIGITAL BLOOD SAMPLE
Abstract
Apparatus for automatically obtaining a percutaneous and digital
blood sample in conjunction with a blood collector device having a
resiliently crushable mouthpiece housing a pair of incisor lancets,
the apparatus including a mounting for the collector device,
clamping means for holding the tip of a finger on the crushable
mouthpiece, a mechanism for striking the collector device in the
mounting to drive the lancets into the finger, and means for
massaging the finger to cause blood to flow out of the resulting
incisions.
Inventors: |
Sanz; Manuel (Grand-Lancy,
Geneva, CH), Revillet; Georges (Petit-Lancy, Geneva,
CH) |
Assignee: |
Micromedic Systems, Inc.
(Philadelphia, PA)
|
Family
ID: |
4371844 |
Appl.
No.: |
04/843,016 |
Filed: |
July 18, 1969 |
Foreign Application Priority Data
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Jul 26, 1968 [CH] |
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11272/68 |
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Current U.S.
Class: |
600/583;
604/22 |
Current CPC
Class: |
A61B
5/150412 (20130101); A61B 5/150068 (20130101); A61B
5/150748 (20130101); A61B 5/150343 (20130101); A61B
5/150022 (20130101); A61B 5/150977 (20130101); A61B
5/15117 (20130101); A61B 5/15113 (20130101); A61B
5/150442 (20130101); A61B 5/150175 (20130101) |
Current International
Class: |
A61B
5/15 (20060101); A61b 010/00 () |
Field of
Search: |
;128/253,329,333,314,315,253,2,DIG.5,275 ;119/14.24,14.25 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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771,890 |
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Aug 1934 |
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FR |
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255,085 |
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Jan 1949 |
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CH |
|
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Howell; Kyle L.
Claims
We claim:
1. An apparatus for obtaining a percutaneous and digital blood
sample from a human finger in conjunction with a blood collector
device comprising a tube in the mouth of which is fitted a
resilient funnel member fitted with at least one incisor lancet
directed towards the open end of the funnel member, said apparatus
comprising a housing, a mounting in said housing, said mounting
formed with a through passage in which a tube can be removably
inserted, said through passage having a predetermined length and a
top and bottom opening; a striker mechanism mounted in said housing
and having a releasable striking member facing the bottom opening
of said through passage, means for releasing said striking member
to propel it toward said bottom opening, said striker member
adapted to strike, when released, the inner end portion of a tube,
in said through passage, thereby to tend to propel a tube out of
said through passage; a clamping means mounted on said housing and
adapted to clamp a finger on said housing in line with said top
opening of said through passage and means for periodically varying
the clamping action of said clamping means whereby at least part of
the tissues of a finger in said holder may alternately be
constructed and released.
2. Apparatus as claimed in claim 1, wherein said clamping means
comprises a supporting block adapted to support a human finger and
a movable shackle adapted to be applied on to the part of a finger
opposite to that which is meant to lie on said block, a lever, a
motor, an eccentric on said motor, said lever drivingly connected
at its one end to said motor through the intermediary of said
eccentric and connected at its opposite end to said block, wherein
said motor is adapted to rotate in a direction such that said block
may be caused to move from the back of a finger towards the front
thereof while at the same time compressing the tissues of the
finger, and wherein the plane in which the eccentric motion of the
block-carrying lever takes place contains the axis of said through
passage, the relative positions of said through passage and of said
block being such that the bottom opening of said through passage
opens in a mean plane substantially equidistant from points, along
the eccentric path followed by the block, respectively
corresponding to maximum and minimum compression of the finger
tissues when a finger is placed on said apparatus.
3. Apparatus as claimed in claim 2, wherein said shackle comprises
a lever which is mounted for pivotal movement in said housing in
the plane of eccentric motion of said block-carrying lever and at a
location opposite to that occupied by said block in relation to
said through passage, said shackle being movable between a first
extreme position in which it is adapted to be applied to a finger
and a second extreme position which is sufficiently far removed
from the first to provide free access to said block and to the
funnel member of a blood collector device when inserted in said
through passage, said apparatus further comprising a means for
locking said shackle in said first extreme position and a return
member for moving said shackle away from said first position upon
being released from the action of said locking means.
4. Apparatus as claimed in claim 3, including first and second
switches and an element on said shackle wherein said motor is
supplied with current through at least said first switch adapted to
be closed by said element carried by said shackle when said shackle
is moved towards said first extreme position, and through at least
said second switch controlled by an element adapted to be actuated
by a blood collector device when inserted in said through passage
to close said second switch.
5. Apparatus as claimed in claim 4, and further comprising a light
source arranged to project a beam of light across said through
passage, a photoelectric detector located opposite said source in
relation to said through passage to receive said beam after
crossing said through passage, a photoelectric detector located
opposite said source in relation to said through passage to receive
said beam after crossing said through passage, electronic
amplifying means controlled by said detector, a relay having a
winding armature and core and controlled by said amplifier to
actuate said locking means into releasing said shackle, the
arrangement being such that when, during operation, the blood
accumulating in a tube reaches a level such that it interferes with
the light beam directed towards said detector, said locking means
releases said shackle whereby said return member may move said
shackle away from said first extreme position to open said first
switch and hence stop the motor.
6. Apparatus as claimed in claim 5, wherein the free end of said
shackle is provided with at least one arm having a saw-toothed
longitudinal edge comprising teeth and said locking means comprises
a lever which is mounted for pivotal movement between first and
second end positions, a return member, said lever having a stem,
said lever adapted to be subjected to the action of said return
member tending to hold it in said first position and said stem
adapted to come into meshing engagement with said teeth on said arm
when said lever is in said first end position and said shackle has
been moved to said first extreme position, said second end position
being such that said stem cannot come into meshing engagement with
said teeth on said arm when said lever is in said first end
position and said shackle has been moved to said first extreme
position, said second end position being such that said stem cannot
come into meshing engagement with said teeth, and wherein the lever
of said means carries the winding and the core of said relay and
further carries the armature of said relay for pivotal movement
between a first angular position remote from said core, which it
occupies when said winding is not energized, and a second angular
position in contact with said core, which it occupies when said
winding has been energized, said apparatus further comprising a cam
associated with said block-carrying lever, which is so positioned
as to come into contact with one end of the relay armature, when
said relay has been energized, and which is adapted to move said
armature in a direction such as to cause the lever of said
mechanism to be rocked into its second end position.
7. Apparatus as claimed in claim 6, and further comprising a
manually actuatable push button cooperating with the lever of said
locking means and adapted, when pressed, to rock said lever into
its second end position against the action of the return member
associated therewith.
8. Apparatus as claimed in claim 6 wherein said mounting lies
between said block and the pivotal axis of said shackle and is
formed with a pair of limbs, and wherein said striking member
includes a rocking lever which extends between said limbs, which is
pivotally mounted to the side of said mounting furthest from the
pivotal axis of said shackle, and which has a projecting free end
portion to the side of said mounting nearest the pivotal axis of
said shackle, a spring means, said rocking lever freely resting in
an inoperative position on a support which is subjected to the
action of said spring means tending to return said lever to said
inoperative position when it has been moved away therefrom in the
direction of the base of said limbs, and wherein the striking lever
has a length such that, upon being rocked, the path traveled by the
tip of its free end portion may intersect the circular path
traveled by an actuating member associated with said shackle when
said shackle is about to reach said first extreme position, so
that, upon said armature being pivoted from its second extreme
position to its first extreme position, said shackle will cock said
striking member against the action of said spring means, said
cocking action lasting for as long as the respective circular paths
traveled by the tip of said free end portion and by said actuating
member intersect one another, said striking member being released
from the action of said actuating member as soon as these paths
cease to intersect one another and then being subjected to the sole
action of said spring means which thus propel it towards the bottom
opening of said through passage in said mounting.
9. Apparatus as claimed in claim 8, wherein said free end portion
has a rounded surface whose center of curvature coincides with the
pivotal axis of said shackle when said striking member has been
moved into an intermediate position lying between said inoperative
position and a position adjacent the rear end of said through
passage, the radius of said curvature being slightly greater than
the distance between the pivotal axis of said shackle and the
portion of said actuating member farthest from said axis.
10. Apparatus as claimed in claim 1, wherein said finger holder
comprises a stationary block for supporting the fleshy part of a
finger, and a U-shaped shackle having limbs straddling said block
on opposite sides thereof and a transverse portion adapted to
engage the topside of a finger, said shackle being movable in a
plane which is parallel to its limbs and which contains the axis of
said through passage, a motor and eccentric and said shackle being
drivingly connected to said motor through the intermediary of said
eccentric underneath said block whereby it may exert on a finger a
pressure during that part of its motion when said eccentric moves
away from block and to relax said pressure when said eccentric
moves towards said block, the direction of rotation of said motor
being such that said shackle is caused to move from the back of a
finger towards the front during that part of its motion when it
exerts on a finger a compression.
11. An apparatus as claimed in claim 1 wherein said clamping means
comprises a finger-supporting block and a movable shackle adapted
to be applied onto the part of a finger opposite to that which is
meant to lie on said block, a motor mounted in said housing and an
eccentric, a lever drivingly connected at its opposite end to said
motor through said eccentric, said block being mounted on one end
of said lever wherein said motor is adapted to rotate in a
direction such that said block is caused to move from the back of a
finger clamped in said clamping means towards the front thereof
while at the same time compressing the tissues of the finger, and
wherein the plane in which the eccentric motion of the
block-carrying lever takes place contains the axis of a tube when
it is in the said through passage, the relative positions of a tube
and of said block when a tube is in said mounting means being such
that the rear portion of the tube is adapted to open in a mean
plane substantially equidistant from points, along the eccentric
path followed by the block, respectively corresponding to maximum
and minimum compression of the finger tissues.
12. An apparatus as in claim 1 wherein said clamping means is
associated with said means for releasing said striker member
whereby said striker means is released when a finger is clamped in
place on said housing.
Description
This invention relates to apparatus for obtaining a percutaneous
and digital blood sample.
A percutaneous and digital blood sample can be obtained as follows:
once the finger has been disinfected, its skin is pricked by means
of a stylet to a depth of about 2 to 3 mm.; this causes a first
drop of blood to appear that contains a relatively substantial
quantity of liquid originating from the subcutaneous cells and
which is eliminated by swabbing it with, for example, cotton wool.
The pricked finger is then massaged towards the incision to urge
further drops of blood to appear and these further drops are
collected in a test tube or a capillary, or are sucked into a tube
open at both ends.
The different stages of taking a blood sample are generally carried
out by specialist personnel although some of these stages, in
particular the preliminary preparation of the finger to be pricked,
could quite readily be carried out by the subject himself.
An object of the invention is to automate the various operations
that are involved in the taking of a percutaneous and digital blood
sample in such a way that the subject from whom the sample is to be
taken can himself take this sample, practically without the
intervention of trained personnel.
According to the invention there is provided apparatus for
obtaining a percutaneous and digital blood sample in conjunction
with a blood collector device which comprises a tube in the mouth
of which is fitted a resilient funnel member fitted with at least
one incisor lancet directed towards the open end of the funnel
member, said apparatus comprising a mounting formed with a through
passage in which said tube can be removably inserted up to said
funnel member to support the blood collector device, said through
passage having a length less than the length of said tube whereby
the inner end portion of the tube will project out of the rear end
of said through passage when said funnel member comes into contact
with the mounting adjacent the front end of said through passage; a
striker mechanism having a releasable striking member facing the
rear end of said through passage and adapted to strike, when
released, the inner end portion of the tube, when the latter is
inserted in said through passage, thereby to tend to propel said
tube out of said through passage so that when a portion of the
finger from which a blood sample is to be taken is placed on the
funnel member at the open end thereof, said resilient funnel member
is caused to deform to allow said lancet to be driven into the
finger to effect a percutaneous incision therein; a clamping finger
holder; and means for periodically varying the clamping action of
said holder whereby at least part of the tissues of a finger in
said holder may alternately be constricted and released.
In the accompanying diagrammatic drawings:
FIG. 1 is a perspective transparent view showing the main component
parts of one constructional of apparatus according to the
invention;
FIGS. 2 to 9 are sections taken across the middle of the apparatus
shown in FIG. 1, showing the various positions occupied by the
component parts of this apparatus in the course of a blood sampling
operation;
FIG. 10 is a diagram of the electric control circuit of the
apparatus shown in FIG. 1;
FIGS. 11 and 12 are sectional elevations of a blood collector
device that can be used with the FIG. 1 apparatus; and
FIGS. 13 to 16 show, in sectional elevation, various stages in the
operation of a modified detail of the FIG. 1 constructional form of
apparatus.
The apparatus shown in FIGS. 1 to 9 comprises a casing 1 having a
base 2, formed by a rectangular plate, and a covering body 3
removably mounted on the base 2. The base 2 and the body 3 are
preferably made of a synthetic plastics material.
The body 3 is formed in its front wall with a circular opening 3a
(FIG. 2) through which projects a pushbutton 4; in its rear wall
with a rectangular cutout 3b which extends over the entire height
of the rear wall to accommodate a block 5 secured to the base 2;
and in its top wall with a pair of rectilinear parallel slots 3c
which extend from the upper edge of the cutout 3b towards the
front, with a first, circular, opening 3d located in front of the
slots 3c, a second, rectangular, window 3e through which projects a
block 6, and with another pair of rectilinear parallel slots 3f
which are located between the opening 3e and the front wall and
which are in alignment with the slots 3c.
Block 5 has pivotally mounted on the upper portion thereof, at 7, a
shackle 8 having a hollow portion 8a of U cross section in which is
secured, as by adhesive, a pad of synthetic sponge 9. In the region
of pivot 7, the shackle 8 is formed with a pair of parallel lugs 8b
coplanar with the limbs of portion 8a and connected to one another
by a pin 8c (FIG. 1). One of the lugs 8b has secured to the outside
thereof a stud 8d adapted to actuate a switch 10, mounted on the
base 2 beside block 5, when the shackle 8 reaches a predetermined
angular position upon being swung clockwise about pivot 7, as will
be explained in greater detail further on.
The spacing between lugs 8b is equal to that between the slots 3c
and their thickness is slightly less than the width of these slots
so that they may move freely therethrough when the shackle 8 is
swung backwards and forwards as for example between the positions
shown in FIG. 2 and in FIG. 4.
On the pivot 7 is mounted a spring 11 having a downwardly
projecting arm on which the pin 8c can come to bear whenever the
shackle 8 is moved clockwise into the position shown in FIG. 3 and
beyond (FIGS. 4 to 6).
At the end remote from the pivot 7, the shackle 8 is extended by a
pair of parallel arms 8e coplanar with the limbs of the central
portion 8a and having a slightly arcuate outline centered on pivot
7. The distance between the center line of each arm 8e and the axis
of pivot 7 is substantially equal to the distance between this axis
and the middle of each slot 3f. Moreover, the spacing between the
arms 8e is equal to that between the slots 3f whereas their width
and their thickness are slightly less than the length and the width
of these slots so that when the shackle 8 is swung clockwise or
forward, for example to the position shown in FIG. 4, its arms 8e
may pass freely into the slots 3f, over their entire length if need
be. The outer edges of the arms 8e are moreover each formed with a
series of saw teeth 8f.
In front of the block 5 is provided a mounting 12 having a
transverse portion at the top thereof and a pair of legs which are
secured to the base 2 and which are formed with a pair of upwardly
extending slots 12a wherein are slidably mounted the end portions
of a pin 13 subjected to the action of a pair of tension springs 14
on the outside of the mounting 12 and secured at their top ends to
a pair of studs 12b.
The transverse portion of the mounting 12, which lies beneath the
opening 3d in the casing body, is formed with several passages,
i.e., a first passage, 12c, which extends generally upwardly though
the middle of the transverse portion and which lies opposite the
opening 3d ; a second passage, 12d, which extends horizontally
through part of the transverse portion between the passage 12c and
the front face of the mounting 12; and third and fourth passages,
12e (FIG. 1) and 12f (FIG. 2), which extend horizontally and
coaxially from the passage 12c to the opposite side faces of the
mounting 12, passages 12e and 12f lying at a level slightly higher
than passage 12d and at right angles to the latter.
Passage 12c is adapted slidably to receive a tube forming part of a
blood collector device 15 which will be described in greater detail
later with reference to FIG. 11; the length of passage 12c is less
than that of the tube. Passage 12d has slidably mounted therein an
actuating element for controlling a switch 16 which is mounted on
the front face of the mounting 12 and the utility of which will
become apparent later. Passage 12e serves to house a photoelectric
cell C (FIG. 10) and passage 12f serves to house an electric bulb A
(FIG. 10) for illuminating the cell C.
Between the legs of the mounting 12 there is pivotally mounted a
lever 17 on a pin 18 whose end portions extend into the legs. The
lever 17 is made of a material having a relatively high specific
weight, e.g. brass or copper, and rests on the sliding pin 13. At
its free end, the lever 17 is formed with an upwardly turned
portion 17a in the tip of which is formed a groove 17b parallel to
its pivotal axis. The width of the lever 17 is less than the
spacing between the lugs 8b of shackle 8 to allow relative movement
between these parts.
It should be noted that the position of the mounting 12 on the base
2 is so chosen that the mean vertical plane of the mounting, along
which the cross sections of FIGS. 2 to 9 have been made, is also
the mean plane of the shackle 8. Further, the length of the springs
14, the length of lever 17 and the position of the pivotal pin 18
are such that when the shackle 8 is swung clockwise or forwards in
the direction of arrow F (FIG. 2), the pin 8c, in the course of its
circular motion, comes into engagement with the lever 17, in
particular with its upwardly turned portion 17a (FIG. 2), and the
circular path traveled by the tip of this portion 17a, when lever
17 is moved anticlockwise by the pin 8c in the direction of arrow
F.sub.1 against the action of springs 14, moves away from that
traveled by the pin 8c before the latter comes into contact with
the block 5 and in particular reaches the bottom of a notch 5a
formed in this block (FIG. 3).
Thus, if the shackle 8 is swung in the direction F (FIG. 2), the
springs 14 are caused to tension as soon as the pin 8c comes into
contact with lever 17 and this tensioning action will continue
until the circular paths traveled by the pin 8c and by the tip of
lever portion 17a cease to intersect one another, i.e. shortly
after the pin 8c has entered into the retaining groove 17b formed
along the tip of lever portion 17a.
If the swinging motion of the shackle 8 is continued in the
direction of arrow F, the pin 8c moves out of the groove 17c and
altogether disengages the lever 17 so that the latter, through
being released, finds itself suddenly subjected to the sole action
of the tensioned springs 14 which cause it to swing abruptly in a
direction opposite to that of F.sub.1 , i.e. towards the passage
12c in the mounting 12 thereby to strike the base of the blood
collecting tube of device 15 (FIG. 4). The effect of this striking
action will be described further on.
The illustrated apparatus comprises, as already stated, a block 6
which projects through an opening 3e formed in the top wall of the
casing body 3. This block 6 is formed in its upper surface with a
V-shaped recess 6a and is fixed to a lever 19 mounted on an
eccentric (not shown) driven by the output shaft 20 a powered by an
electric motor M via a speed reducing gear of which one wheel can
be seen at 20 in the drawings. The lever 19 is formed with an
abutment 19a adapted to engage one end of a lever 21 carrying the
armature 22 of a relay having a winding 23 and a magnetic circuit
24. The lever 21 is pivotally mounted at 21a on a further lever 25
which is in turn pivotally mounted at 25a on a block 26 secured to
a platform 27 which also supports the motor M and which in turn
rests on the base 2 of the apparatus via a socle 28. Through the
top end of lever 25 extends a stem 29 in which is formed a notch
29a extending along its entire length thereby to form a
sufficiently sharp catch to engage with the teeth 8f along the
front edges of the arms 8e of shackle 8 when the latter has been
swung down (FIGS. 4 to 6).
A spring 30 which is secured at one end to the block 26 and which
bears near its opposite end on the stem 29 serves to keep the
latter in a position of engagement. The magnetic circuit 24 and its
winding 23 are mounted in the opening of a supporting frame 31 to
one side of which are provided a pair of projecting lugs 31a by
means of which the frame 31 can be mounted on lever 25, the lugs
being secured to the opposite faces of lever 25.
The block 26 is formed with a horizontal passage 26a through which
extends a slidable pin 26b whose ends contact the lever 25 and the
pushbutton 4 respectively. Thus, by pressing on the button 4 in the
direction of arrow F.sub.3, the lever 25 can be made to rotate in
the direction of arrow F.sub.2 about its pivotal axis 25a and
against the action of the spring 30.
As for lever 21, it can occupy either of two positions depending on
whether or not the relay winding 23 is energized. In the position
which corresponds to the unenergized state of the winding 23 and
which is that shown for instance in FIGS. 1 and 2, lever 21 comes
to bear under the action of its own weight on a pin 21b secured to
the casing of motor M, so that the projection 19a on lever 19
cannot come into contact with lever 21, whatever may be the
position occupied by lever 19 in the course of its eccentric
motion. But upon energization of the winding 23, the field that is
set up by the magnetic core 24 causes the armature 22 to be
attracted thereby causing lever 21 to be rocked about its pivotal
axis 21a into a raised position (FIGS. 6 and 7) in which its tip
comes to lie in the path of travel of the projection 19a. Upon this
projection coming into engagement with lever 21 (FIG. 7), the
latter is tipped up thereby causing the whole unit that is made up
of the lever 21, the frame 31 that carries the winding 23 and its
core 24, the lever 25 and the notched stem 29, to be rocked about
pin 25a in the direction of arrow F.sub.2. Thus if the shackle 8
happens to be at that time in its lowered position with its teeth
8f in meshing engagement with the notched stem 29, then the latter
will be made to disengage from these teeth thus causing the shackle
8 to be subjected to the sole action of its spring 11 and hence to
be swung upwards in a direction opposite to arrow F (FIG. 2).
A similar result can be achieved by pressing on the pushbutton 4 in
the direction of arrow F.sub.3, since in so doing pin 26b is caused
to slide from right to left in the passage 26a to rock lever 25 in
the direction of arrow F, this being the direction required to
disengage the notched stem 29 from the teeth 8f.
The motor M, the lamp A and the winding 23 are supplied with
electric current by means of a circuit which is diagrammatically
illustrated by FIG. 10. In this FIG. are also to be found the
switches 10 and 16, here referenced 10* and 16*, the photoelectric
cell C, the magnetic core 24 of winding 23, and the pushbutton 4,
here referenced 4*. The positional relationship of elements 4, 10,
23 and 24 does not in this Figure correspond in any way to reality
but their functional representation is however correct. Thus, upon
lever 21 being attracted by the winding 23, the shackle 8 is
released from the stem 29 and swings upwards under the action of
the spring 11 causing the stud 8d to open the switch 10.
The same result can be achieved, as already stated, by actuating
the pushbutton 4, and this explains why there is shown a pushbutton
4* acting directly on the movable contact of a switch 10*.
Moreover, because the shackle 8 is the member that governs the
closure of the switch 10, its function has here been symbolized by
an arrow 8*.
As shown in FIG. 10, the electric circuit of the apparatus, which
is supplied with current by a source S consisting of a series of
cells housed in a casing S.sub.1 (FIG. 1) secured to the base plate
2, comprises an amplifier which includes a pair of NPN-type
transistors, T.sub.1 and T.sub.2 , a pair of PNP-type transistors,
T.sub.3 and T.sub.4, and a resistor R.sub.2, this amplifier being
controlled by the photoelectric cell C and serving to ensure
energization of the winding 23 upon receipt of a suitable signal
from the cell C.
It should here be pointed out that the cell C and the source of
illumination A serve to determine when the transparent or
translucent tubular body of the collector device 15 has been filled
with a sufficient quantity of blood, the cell producing signals
which are different when receiving a light beam of full intensity
from source A or a light beam of lesser intensity, as when the
blood that has collected in the tube has reached the level of the
light beam issuing from source A. It should however be noted that
the supply of current to the light source A, which takes place
through a resistor R.sub.1, only occurs when the switches 10 and 16
are closed, i.e. only when the shackle 8 has been swung into its
lowered position (FIG. 4) and when a blood collector device 15 has
been inserted into the passage 12c of the mounting 12. The same
applies to the motor M which can only be supplied with current when
these switches have been closed.
Thus, upon the blood being collected in the tube of device 15
reaching the level of the light beam projected by the source A
towards the photoelectric cell C, the switch 10 will be made to
open the motor M will hence be made to stop.
The amplifier, consisting of transistors T.sub.1 to T.sub.4 and of
resistor R.sub.2, and the resistor R.sub.1 are housed in a casing B
mounted on the platform 27.
Before describing the operation of the illustrated apparatus, a few
particulars will be given about a preferred form of blood collector
device that can be used in conjunction with the apparatus for
taking and collecting a blood sample (FIG. 11).
This device comprises a tubular body 32 of transparent or
translucent material, for example polyethylene, in the mouth of
which is engaged a plug 33 constituting the lower, discharge, part
of a funnel member 34 having a cuplike portion 35 of resilient
plastics material. The cup 35 rests on the rim of the mouth of the
tubular body 32 by means of an annulus 35a provided at the base of
the cup 35. The wall of the cup 35 and the plug 33 are formed with
an L-shaped groove 36 forming a passage which allows the air
contained in the tubular body 32 to escape as the latter is being
filled with liquid, in particular blood.
At the lower end of plug 33 there projects a capillary cannula 37
extending nearly to the bottom of the body 32, coaxial with said
body and forming an extension of an axial passage in the plug 33.
The plug 33 and the cannula 37 form an integral unit made of
synthetic resin.
At the bottom of the cup 35 is provided an annular groove 35b in
which is held the peripheral part of a circular metal plate 38, for
example of stainless steel, which is provided with two triangular
lancets 38a and 38b extending perpendicularly to the plate 38, on
opposite sides of a slot 39 in said plate.
Above the plate 38 in the cup 35 is arranged an annular pad 40 of
absorbent material, e.g. blotting paper, impaled on and held in
position by the lancets 38a and 38b. As shown, the slot 39 and the
opening in the pad 40 lie opposite one another and are in alignment
with the central passage in plug 33.
The part of the lancets 38a and 38b that projects above the pad 40
has a length of at least 2 to 3 mm.; these lancets may extend
further but not beyond the level of the upper rim of cup 35.
It is these lancets 38a and 38b which are intended to form the
cutaneous incisions that have to be made for taking a blood sample,
as will now be seen.
The apparatus described with reference to FIGS. 1 to 9 operates as
follows:
When the shackle 8 is in its raised position shown in FIGS. 1 and
2, a blood collector device 15 is inserted through the opening 3d
in the casing body 3, and into the passage 12c of mounting 12 until
the funnel member of the device 15 comes to rest on the mounting 12
at which point the lower end portion of its tubular body will
project into the space lying between the legs of the mounting 12,
as shown in FIG. 3.
Once the subject's finger from which a blood sample is to be taken
has been duly cleaned and disinfected with dilute alcohol, at least
over the fleshy part of the top joint (underneath the nail), the
subject lays his hand on the apparatus casing 1 and places the tip
of his disinfected finger on the mouth of the cup formed by the
funnel member of device 15, and places the middle joint and the
adjoining part of the top joint of this finger in the V-shaped
recess 6a that is provided in the block 6.
The shackle is then moved in the direction of arrow F to bring it
into the position shown in FIG. 4. Once the shackle has traveled
through a certain angular distance, the pin 8c comes into
engagement with the top surface of the lever portion 17a to depress
the lever 17 and hence to tension the springs 14. When the pin 8c
reaches the groove 17b along the tip of the lever portion 17a the
arms 8a of the shackle start to extend through the slots 3f in the
casing body 3 without however yet being in a position where the
teeth 8f can begin to come into meshing engagement with the notched
stem 29 (FIG. 3). It is in this position of the shackle 8 that the
pin 8c begins to bear on the spring 11.
With the shackle 8 being moved further down, the pin 8c moves out
of the groove 17b and slips off the cocked lever 17 thereby
triggering off the latter to strike, under the action of the
springs 14, the base of the tubular body 32 of the blood collector
device 15 (FIG. 4). The device 15 cannot, as a unit, rise beyond
the point where the subject's finger is resting on the top of its
funnel member 34, but because the walls of the cup 35 are
collapsible, in view of the fact that the funnel member 34 is made
of resilient material, and because the tubular body 32 is slidingly
mounted in the passage 12c of mounting 12, the tubular body 32 can
nonetheless be made to move upwards under the percussive action of
the striking lever 17 to drive the lancets 38a and 38b into the
flesh of the finger (FIG. 12) to a depth corresponding to the
length of the projecting portions of the lancets, thereby making
the desired incisions in the epidermis and the dermis.
Once lever 17 has imparted all its kinetic energy to the blood
collector device, it ceases to exert any force on the latter and
drops back on to the sliding pin 13. Thus, once the desired
incisions have been made, the tubular body 32 will be forced back
to its initial position under the action of the deformed elastic
walls of the cup 35 tending to resume their normal uncollapsed
position (FIG. 11), and the lancets 38a and 38b will be withdrawn
from the incisions they have made although remaining in close
proximity to the latter.
While the striking action is taking place, the shackle 8 will have
reached the position shown in FIG. 4. In this position the pad 9
has come to bear on the top of the first and second finger joints,
the notched stem 29 has come into engagement with the teeth 8f
provided along the shackle arms 8e, and the stud 8d has caused the
switch 10 to close so that the control circuit for the apparatus
may supply electric current to the motor M, the lamp A and the cell
C.
In this position of the shackle 8 also the finger finds itself
tightly held between the block 6, along the bottom, the pad-lined
shackle portion 8a, along the top, and the limbs of the shackle
portion 8a, along the sides, the grip exerted on the finger being
variable, in particular in the plane of FIG. 4. The variable
gripping action exerted by the finger-holding arrangement is due to
the fact that the block 6 is movably mounted and is eccentrically
driven by the motor M in the direction of arrow f (FIG. 4) since in
the course of this eccentric motion, the block 6 is made to move to
and from in relation to the incised tip of the finger and is also
made to move upwards as it moves towards the incised finger tip and
to move downwards as it moves away from the incised finger tip.
The finger thus finds itself being periodically subjected to a kind
of massaging action from back to front by compression of the part
of the finger that lies on the block 6, and this massaging action
causes the blood flowing to this part of the finger to be urged
towards the incisions so as to issue therefrom in the form of drops
which are collected in the cup of the funnel member of device
15.
It is to be noted that the first few drops of blood thus collected
in the cup contain a high proportion of physiological liquid which
originates from the subcutaneous cells lying near the incisions and
which is clearly undesirable in the blood sample. That is why there
is provided at the bottom of the funnel member cup 35 an absorbent
pad 40 which will soak up these few drops of impure blood and it is
only when the pad 40 has been sufficiently impregnated with a
mixture of physiological liquid and blood, that the clean blood
then issuing from the finger will begin to flow into the tubular
body 32. In this connection it is to be noted that the lancets
considerably facilitate this flow because, although removed from
the epidermis, they remain directly opposite the incisions they
have made and are at a sufficiently short distance from them to
enable the drops of blood issuing from the incisions to fall on and
be ruptured by the tips of the lancets, whereupon they will flow
rapidly over the surface of the latter into the outlet opening of
the funnel member 34. The lancets thus play the part of effective
collectors preventing the formation of a thick blood dispersion in
the cup 35.
When the level of the blood that has accumulated in the tubular
body of the collector device 15 has reached a sufficiently high
level to interrupt or interfere with the light beam directed to the
cell C, the latter causes the relay winding 23 to be energized, as
already described, thereby to move the lever 21 to its raised
position (FIG. 6) and hence to release the shackle 8 from
engagement by the notched stem 29 whereby the shackle 8 may move to
the position shown in FIG. 7. The switch 10 is, as a result, opened
so that the motor M and the lamp A cease to be supplied with
electric current. The massaging action of the finger then stops and
since the latter is no longer gripped in the holding means formed
by the shackle 8 and the block 6, the subject can remove his hand
from the apparatus.
As can be seen from FIGS. 3 to 7, the blood collector device 15 is
so positioned in the apparatus that it would be particularly
difficult for it be extracted from the latter by hand, once full.
That is why the extraction operation is here done, at least
partially, in a mechanical manner. This is achieved by lifting the
shackle 8 into the position shown in FIG. 8 since, in doing so, the
pin 8c comes to bear on the underface of the lever portion 17a and
progressively comes to lift lever 17 which in turn gradually lifts
the blood collector device out of the casing body 3, until such
time as the lever 17 abuts against the underside of the transverse
portion of the mounting 12.
It will be observed that the underface of lever portion 17a has a
rounded outline, that the center of curvature of this rounded
outline comes to coincide substantially with the pivotal axis 7 of
the shackle 8 when the shackle 8 reaches the FIG. 8 position, and
that radius of this rounded outline is slightly greater than the
distance between the pivotal axis 7 and the oppositely facing
surface of the pin 8c. Consequently, when the lever 17 is in the
FIG. 8 position, there is nothing to prevent the shackle 8 from
being swung back further to the position shown in FIG. 9, this
being the same position as the starting position shown in FIG. 2,
and once the pin 8c has been raised to a level higher than the tip
of lever portion 17a, the lever 17 will drop back on to the sliding
pin 13, and the apparatus is then ready for a fresh blood sampling
operation.
FIGS. 13 to 16 illustrate a modified constructional form of finger
holder. This holder, which also serves to maintain a finger by its
tip on a blood collector device and to massage the finger whereby
blood is made to flow towards the incisions made in the finger tip,
comprises a stirruplike member 41 whose limbs extend through slots
(not shown) into the casing 42 of the apparatus where they are
pivotally mounted on a pin 43 eccentrically driven by the output
shaft 44 of a motor (not shown), and further comprises a swell 45
which is provided on the top surface of the casing 42 between the
limbs of the stirruplike member 41 and on which the subject from
whom a blood sample has to be taken is meant to put one of his
fingers. Underneath the top of member 41 there is provided a pad 46
of synthetic sponge via which member 41 comes to bear on the
finger.
The manner in which the finger is massaged as illustrated by FIGS.
13 to 16 wherein the stirruplike member 41 is shown occupying four
different positions as a result of the shaft 44 having been rotated
each time through 90.degree. in relation to the previous
position.
The illustrated apparatus has of course only been given by way of
example and a number of other constructional forms could be
envisaged. For instance, instead of being portable, as described,
and being run off batteries, the apparatus could be designed to be
normally static and be adapted to be supplied with electricity off
the mains.
Also, different constructional forms of blood collector devices can
be used in the illustrated form of apparatus and a number of such
devices, in addition to that illustrated in FIG. 11, have been
described and illustrated in our copending Pat. application Ser.
No. 843096, filed July 18, 1960, entitled "Blood Collector
Device."
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