IL32707A

IL32707A - Apparatus for obtaining a percutaneous blood sample

Info

Publication number: IL32707A
Application number: IL32707A
Authority: IL
Original assignee: Battelle Development Corp; Micromedic Systems Inc
Priority date: 1968-07-26
Filing date: 1969-07-25
Publication date: 1972-10-29
Also published as: IL32706A0; AT292910B; SE348932B; DE1938870B2; IL32706A; FR2013819A1; BE736573A; JPS4841632B1; US3626929A; SE348931B; JPS4841633B1; IL32707A0; AT292911B; DE1938870A1; NL6911527A; GB1277762A; DE1938871B2; NL6909366A; DE1938871C3; CH500707A

Description

Ap arat s for ©Ttaisaia^ a poro aaoo s blood saiapX® MICHCMBDXO δϊΟΪΕΕΐδ p I C.

This invention relates to apparatus for use in digital obtaining a/percutaneous blood sample.

A percutaneous blood sample can be obtained for example from a finger, 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.; a first drop of blood then appears and this contains a relatively large amount of liquid originating from the subcutaneous cells and which is usually eliminated by swabbing it with, for example, cotton wool.

The pricked finger may then be massaged towards the irrcision drops of to urge further/blood to appear and these further drops are v collected for example in a test tube or a capillary, or may be sucked into a tube open at both ends.

The . different stages of taking a blood sample are generally carried out by qualified personnel who are now · becoming more and more scarce. The apparatus of the invention is useful in obtaining a sample without the necessity of specialist attention. It is particularly useful in obtaining a. sample. for collection in an apparatus as claimed in our Israeli Application No. 32,706 which describes and claims apparatus for collecting a blood sample comprising a collection collector least one tube with a resilient ftwmei cup at an open end, atyiance the inside the cup, directed towards -44s open end and such that it projects from the cup only when the cup is compressed by axial pressure, and a mass of absorbent material in the cup with the lance projecting through it.

According to the invention there is provided apparatus capable of use in obtaining a blood sample in a collection tube to be held against a percutaneous digital incision, which apparatus comprises a device for holding an incised part of the digit against a collection tube, when such a tube is in pos- the apparatus ition in/device, and a device for stimulating the flow of blood from the incision.

In a preferred apparatus in accordance with the invention the stimulating device can exert a periodical variable clamping action alternately to constrict and release tissues of the digit near to the incision, for example it may comprise a block moveable to impart stroking pressure to the digit. In this embodiment the clamping action may result from pressure on the digit between the block and the holding device.

Preferred embodiments of the invention will now be particularly described, for the purposes of illustration only, with reference to the accompanying drawings in which descriptions of orientation, such as "upwards" and "downwards" refer to the embodiment in its normal operating position placed on a horizontal surface and in which: •Figure 1 is a perspective cut away view showing the main component parts of a first embodiment of the invention together with a blood collector device in position: Figures 2 to 9 are sections taken across the middle of the embodiment shown in Figure 1, showing the positions of component parts of this embodiment at different stages in a blood sampling operation; Figure 10 is a diagram of an electric control circuit of the embodiment of Figure 1; Figures 11 and 12 are sectional elevations of a blood collector device that can be used with the embodiment of Figure 1 ; and Figures 13 to 16 show, in sectional elevation, a modification of a detail of the embodiment of Figure 1 in different stages of operation.

The embodiment apparatus shown in Figures 1 to 9 comprises a casing 1 having a base 2, formed by a rectangular plate, and a cover 3 removably mounted on 'the base 2. The base 2 and the cover 3 are made of a synthetic plastics material.

The cover 3 has in its front wall , a circular opening 3a (Figure 2) through which projects a push button 4 ; in- its rear wall is rectangular cut-out 3b extending to the full height of the rear wall to accommodate a block 5 secured to the base 2 ; and in its top wall is a pair of rectilinear parallel slots 3c which extend from the upper edge of the cut-out 3b towards the front of the casing with a first, circular, opening 3_d located in front of the slots 3c, a rectangular, window 3e_ through which projects a block 6, and another pair of rectilinear parallel slots 3f located between the opening 3e and the front wall and in alignment with the slots 3c_.

Block 5 has pivotally mounted on the upper portion thereof, at 7, a shackle 8 having a portion 8a of U cross-section in which is secured, by adhesive, a pad of synthetic 9 sponge/ Near pivot 7, the shackle 8 has a pair of parallel lugs 8b coplanar with the limbs, of portion 8a_ and connected to one another by a pin 8c (Figure 1). One of the lugs 8b has secured to the outside thereof a stud 8d for actuating a switch 10, mounted on the base 2 beside block 5 , when the shackle 8 reaches a predetermined angular position on being swung clockwise as seen in Figures 1 to 7, about pivot 7,.as will be explained in greater" detail later.

The space between the 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 Figure 2 and Figure e On the pivot 7 is mounted a spring 11 having a . downwardly projecting arm (Figure 2) on which- the pin 8 can bear whenever the shackle 8 is moved clockwise into the position shown in Figure 3 and beyond (Figures 4 to 6).

At the end remote from the pivot 7, the shackle 8 is extended by a pair of parallel arms 8_e coplanar with the limbs of the central portion 8a_ and having a. slightly arcuate outline centered on pivot 7. The distance between the centre 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 space 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 respectively of these slots so that when the shackle 8 is swung clockwise for example to the position shown in Figure 4, its arms 8e can pass freely into the slots 3f over their entire length. The outer edges of the arms 8e are each formed with a series of. saw teeth 8_f, which, as hereinafter described, act as ratchet teeth.

In front of the block 5 is a mounting 12 having a transverse portion at its top and a pair of legs , secured to the base 2, which are formed with a pair of upwardly extending slots 12a wherein are slidably mounted the end portions. of a pin 13 subject 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. χ The transverse portion of the mounting 12, which lies beneath the opening 3d in the casing, is formed with several passages: a first passage, 12c_, which extends generally upwardly through 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_ (Figure'D and 12f_ (Figure 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 can slidably receive a blood collection tube 15 forming part of a device as 'described and claimed which will be described in greater detai in our Israeli Application 32,706 and^later with reference to Figures 11 and 12 ; 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 12_e houses photo-electric cell C (Figures 1 and 10) and passage 12f houses an electric bulb A (Figure 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 brass extend into the legs. The lever 17 is made of a .. material which has having a relatively high specific weight, b-3?ae-s-, and rests on the sliding pin 13* At its free end, the lever .17 has an upwardly turned portion 17a in the tip. of which is a groqve 17b parallel to its pivotal axis. The width of the lever j!7 is less than the spacing between the lugs 8b of. shackle j8 to allow relative movement of the lever between these lugs.

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 Figures 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 pivot 18 are such that when the shackle 8 is swung in the direction of arrow F (Figure 2), the pin 8c_, in the course of its circular motion, engages lever 17, at its upwardly turned portion 17a (Figure 2), and the V circular path travelled by the tip of this portion 17a, when lever 17 is moved anticlockwise by the pin :8c in the direction of arrow against the action of springs 14, diverges from that travelled 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 (Figure 3).

Thus, if the shackle 8 is swung in the direction F (Figure 2), the springs 14 begin to come into tension as. soon as the pin 8c comes into contact with lever 17 and this tension increases until the circular paths travelled. by the pin 8c and by the tip of lever .portion 17a cease to intersect shortl after pin 8c_ has entered the retaining groove 17b in the tip of lever portion 17a.

■ If the swinging motion of the shackle 8 is continued in the direction of arrow F, the pin 8 moves out of the .groove 17^ and disengages the lever 17 so that the latter, is suddenly subjected only to the action of the tensioned springs 14 which cause it to swing abruptly in a direction opposite to that of arrow F^, towards the passage 12c in the mounting 12 and to strike the base of the blood collection tube (Figure 4 The effect of this striking action will be described further on.

The block 6, which projects through an opening 3e formed in the top wall of the casing 3, 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 20a 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 solenoid having a winding 23 and a magnetic circuit 24. The lever 21 is pivoted at 21a on a further lever 25 which is in turn pivoted 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 a notch 29a, extending along its entire length, forming a sufficiently sharp catch to engage as a pawl, with the ratchet teeth 8f along the front edges of the arms 8e of shackle 8 when the latter has been swung down (Figures 4 to 6).

A spring 30, secured at one end to the block 26 and bearing 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 has a horizontal passage 26a through which extends a slidable pin 26b whose ends contact the lever 25 and the push-button 4 respectively.

As for lever 21, it can occupy either of two positions relative to lever 25 depending on whether or not the solenoid 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 Figures 1 and 2, lever 21 bears 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 . 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 (Figures 6 and 7) in which its tip lies in the path of travel of the projection 19a. When this projection comes into engagement with lever 21 (Figure 7), the latter is tipped up thereby causing the whole unit (made up of 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 .F2· Thus.'.if the shackle 8 is at that time in its lowered position with its teeth 8f_ in meshing engagement with the notched (stem 29, then this pawl and ratchet mechanism wil be disengaged so that the shackle 8 is subjected only to the action of spring 11::and is swung upwards in a direction opposite^to arrow F (Figure 2).

A similar disengagement of the pawl and ratchet mechanism can be achieved by pressing on the push-button 4 in the direction of arrow F3, since this makes pin 26b slide from right to left in the passage 26a and rock lever 25 in the direction of arrow F2, 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 diag-rammatically illustrated by Figure 10. This Figure also shows the switches 10 and 16, here referenced 10* and 16*, the photoelectric cell C, the magnetic core 24 of winding 23, and the push-button 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 push-button 4, and this explains why there is depicted in Figure 10 a push-button 4* acting directly on the moveable contact of a switch 10*.

I 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 Figure 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 (Figure 1) secured to the base plate 2, comprises an amplifier which includes a pair of n-p-n type transistors, T^ and T2, a pair of p-n-p type transistors, T^ and T^, and a resistor I^, 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.

The cell C and the source of illumination A determine when a transparent or translucent collection tube 15 has been filled with a predetermxnedly 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 interrupted by blood that has collected in the tube. It should be noted that the supply of current to the light' source A, through a resistor R^, only occurs when the switches 10 and 16 been are closed, i.e. only when the shackle 8 has^swung into its lowered position (Figure 4) and when a collection tube 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 reaching the level of the light beam projected by the source A towards the photoelectric cell C, the switch 10 will open and the motor M will stop.

The amplifier, consisting of transistors T^ to'T^ and of resistor ί^, and the resistor are housed in a casing B mounted on the platform 27.

Figures 11 and 12 show a collection tube (in use in Figure 12) according to our Application No. 32,706 and -suitable for use in conjunction with the apparatus of this invention.

This device comprises a collection tube 32 of transparent or translucent material, in this case polyethylene, Y in the mouth of which is engaged a plug 33 constituting the discharge part of a funnel 34 having a cup 35 of resilient plastics material. The cup 35 rests on the rim of the open end of the tube 32 by means of an annular ridge 35a on the outside of the base of the cup 35. The wall of the cup 35 and the plug 33 have an L-shaped groove 36 forming together with the wall of the collection tube 32 a passage which allows the air contained in the tube 32 to escape as the latter is being filled with blood.

At the discharge end of plug 33 there projects a capillary tube 37 extending nearly to the bottom of the tube 32, co-axial with the tube 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. i . , ' At the bottom of the cup 35 is an annular groove 35b in which is held the peripherylof a circular plate 38 stainless steel which has two triangular lances 38a and 38b at right angles to the plate 38, one at each end of a slot 39 in the plate. · , Above the plate 38 in the cup 35 is arranged an annular mass or pad 40 of absorbent material, in this case blotting paper, impaled on and held in position by the lances 38a and 38b. As ;shown, the slot 39 and the opening in the pad 40 are aligned with the passage in plug 33. each of The part^ of/the lances 38a. and 38b that project above the pad 40 has a length of between 2 and 3 mm (these lances may extend further in other embodiments but not beyond the level of the upper rim of cup 35).

These lances 38a and 38b are for 'making cutaneous incisions required for taking a blood sample.

The apparatus described with reference to Figures 1 to 9 operates as follows : When the shackle 8 is raised as shown in Figures . 1 and 2, a blood collection device 15 is inserted through the opening 3d in the casing 3, and into the passage 12c of mounting 12 until the cup 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 Figure 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 casing 1 and places the tip of his disinfected finger on the mouth of the cup 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. in the block 6.

The shackle is then moved in the direction of arrow F to bring it into the position shown in Figure 4. Once the shackle has travelled through a certain angle, the pin 8 engages the top surface of the lever portion 17a to depress the lever 17 and hence to put into tension the springs 14.

When the pin 8c reaches the groove 17b along the tip of the e lever portion 17a. the arms 8|f 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 mesh with the notched stem 29 (Figure 3). It is in this position of the shackle 8 that the pin 8c begins to bear on the spring 11.

When the shackle 8 is 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 collection device 15 (Figure 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 34, but because the walls of the cup 35 are collapsible, and because the tubular body 32 is slidable in the passage 12_c of mounting 12, the tubular body 32 moves upwards under the striking, action of the lever 17 to drive the laces 38ji and 38b into the flesh of the finger (Figure 12) to a depth corresponding to the length of the projecting portions of the lances, thereby making the desired incisions in the epidermis and the dermis.

Once lever 17 has imparted all its kinetic energy to the blood collection device, it 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 by the resilience of the deformed walls of the cup 35 (Figure 11) and the lances 38a and 38b will be withdrawn from the incisions they have made although remaining close to the latter.

While the striking is taking place, the shackle 8 will have reached the position shown in Figure 4. In this position the pad 9 bears on the top of the first and second finger joints, the notched stem 29 engages the teeth 8f on the shackle arms 8e, and the stud 8d has caused the switch 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 is 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 Figure 4. The variable clamping or 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_ (Figure 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 av/ay from the incise finger tip.

The finger thus finds itself being periodically subjected to a kind of massaging action or. stroking pressure from back to front by compression of the part of the finger that lies on the block 6, arid this causes the blood flowing to this part of the finger to be urged towards and from the incisions as drops which are collected in the cup of the funnel of device 15.

It is to be noted that the first few drops of blood collected in the cup contain a high proportion of physiological liquid which originates from the sub-cutaneous cells lying near the incisions and which is undesirable in a blood sample. That is why there is provided at the bottom of the cup 35 an absorbent pad 40 which will soak up these first few drops of 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 tube 32. In this connection it is to be noted that the lances considerably facilitate this flow because, although removed from the epidermis , they remain directly opposite the incisions they have made and their tips are close enough to rupture the blood drops as they fall so that they will flow rapidly over the lances into the outlet of the . funnel 34. The lances are thus effective collectors preventing the formation of a thick blood dispersion in the cu 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 solenoid winding 23 to be energized, as already described, thereby to move the lever 21 to its raised position (Figure 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 Figure 7. The switch 10 is, as a result, opened so that the motor M and the lamp A are de-energised. The massaging action of the finger then stops and since the latter is no longer gripped between the shackle 8 and the block 6, the subject can remove his hand from the apparatus.

As can be seen from Figures 3. to 7, the blood collection device 15 is so positioned in the apparatus that it would be particularly difficult for it to be extracted from the latter by hand, once full. In this embodiment the extraction operation is done, at least partially, mechanically by lifting the shackle 8 into the position shown in Figure 8. In so doing, the pin 8c bears on the underface of the lever portion 17a and progressively lifts lever 17 which in turn gradually lifts the blood collection device out of the casing body 3, until the lever 17 abuts against the underside of the transverse portion of the mounting 12. ' It will be observed that the underface of lever portio 17a has a rounded outline, that the centre 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 Figure 8 position, and that the 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 Figure 8 position, there is nothing to prevent the shackle 8 from being back swung^further to the position shov/n in Figure 9, this being the same starting position shown in Figure 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.

Figures 13 to 16 illustrate a modified constructional form of finger holder. This holder, which also holds a finger by its tip on a blood collector device and massages the finger to stimulate blood flow towards the incisions,' comprises a stirrup 41 whose limbs extend through slots (not shown) into the casing 42 of the apparatus where they aire 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 stirrup 41 and on which the subject t from whom a blood sample has to be taken is meant to put one of his fingers. Underneath the top 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 is illustrated by Figures 13 to 16 wherein the stirrup 41 is shown occupying four different positions as a result of the shaft 44 having been rotated each time through 90° in relation to the previous position. 32707/2

Claims

CLAIMS If,. Apparatus capable of use in obtaining a blood sample in a collection tube to be held against a percutaneous digital incision, which apparatus comprises a device for holding ah incised part of the digit against a collection tube, when such a tube is in position in the apparatus, and a device for stimulating the flow, of blood from the incision.
2. Apparatus as claimed in Claim 1 wherein the stimulating device can exert a periodical variable clamping action alternately to constrict and release tissues of the digit near to the incision.
3· Apparatus as claimed in Claim 2 wherein the stimulating device comprises a block moveable to impart stroking pressure to the digit.
4. Apparatus as claimed in Claim 3 in which the clamping action of the stimulating device results from pressure on the digit between the block and the holding device,
5. Apparatus as claimed in any preceding Claim wherein the device for holding the digit against the tube comprises a shackle moveable from a position in which the digit can be placed in position to one in which it holds the digit in position.
6. Apparatus as claimed in any preceding Claim wherein the device for holding the digit against the tube Includes a releasable striker mechanism capable in use of striking a collector tube having a lance adjacent the digit, to press it against the digit with sufficient force to cause the lance to make the incision, and a device for holding the tube and the digit in contact after release of the striking pressure. 32707/2 - 21 - ·.,:.
7.. Apparatus as claimed in Claims 5 and 6, in which the shackle has a projection which during movement of the shackle to its digit-holding position causes the striker mechanism to operate,,
■8 . · Apparatus as claimed in Claim 5 or 6 wherein the shackle is lockable in its digit-holding position by a pawl and ratchet device.
9. Apparatus as claimed in any preceding Claim, which also includes a motor.
10. Apparatus as claimed in Claim 9 as dependent on Claim 3 or Claim 9 as dependent on any one of Claims 4 to 8 as dependent on Claim 3» in which the block is mounted on a crank mechanism driven by the motor, the crank mechanism being such as to Impart the stroking movement to the block on operation of the motor.
11. Apparatus as claimed in Claim 2 wherein the holding device and the stimulating device are integral, nd formed by a stirrup into which the incised part of the digit is to be inserted and which is movable to impart stroking pressure to the digit.
12.. Apparatus as claimed in Claim 11 wherein a pad is mounted on the stirrup which is mounted on a crank mechanism driven by a motor, the crank meohanism being such as to impar the stroking movement to the pad on operation of the motor.
13. Apparatus as claimed in Claim 9 or 10 wherein the motor is an electric motor and a motor-activating circuit includes switches one of which, in use, is activated by the presence of a collection tube in the apparatus and another of which, in use, is activated by the location of the digit- 32707/2 r 22 ,r
14 Apparatus as claimed in Claims 5 and 13 wherein the shackle is b ased away from its digits-holding position to a position where it operates the switch associated with the digit-holding device to break the circuit.,
15. Apparatus as claimed in Claims 8 and 14 wherein the shackle-locking device is releaeable in response to a signal from a photoelectric device which determines when sufficient blood has been obtained*
16. Apparatus capable of use in obtaining a blood sample substantially as described with reference to Figures 1 to 10 or to Figures 1 to 10 as modi ied by Figures 13 to 16 of the accompanying drawings. IS:CB