DE2601432B2 - Device for monitoring venous blood for gas bubbles - Google Patents

Description

The invention relates to a device for monitoring venous blood for gas bubbles, which a tube flows through behind a hemodialysis machine, with a housing box for elements of the Monitoring and control electronics, in which at the same time a bubble determination device with a Bubble detector and a hose disconnection device connected therewith are arranged the hose clamp of which clamps the hose off in the presence of bubbles.

From US Pat. No. 28 35 252, which discloses a device for intravenous transfusion including the Monitoring of gas bubbles concerns, a device has become known in which the analysis station and the Clamping device largely outside the housing box, also offset from one another and far are arranged away from each other, so that the hose is guided in an S-shape, which among other things too Difficulties, e.g. B. a cumbersome insertion of the hose, leads. In addition, the hose clamp unlocked via an electromagnet, with a

Ratchet lock is used, which in the intended form with disadvantages when using a thicker hose diameter is connected

Has also become known (US Patent 3832998) a regulating device for intravenous Drip transfusions, in which the measuring device for the uniform drip speed consists of a movable flap wing inside a tube chamber in Connection with a magnetic member and a spring-operated pawl. The hose is for Implementation of this principle in front of and behind the observation chamber through delivery and receiving tubes for the drops rolling over the wing interrupted.

The invention is based on the object of not only accommodating the bubble determination device and the hose removal device in a single housing, but also making the housing so small and so designed that all hose systems common in hemodialysis can be used . self-contained electronics must be available for both the bubble determination device and the hose clamp device.

In addition, the measurement conditions between the transmitter and receiver should always be reproducible Bubble determination device and an exact shut-off of the hose in the hose clamp device can be achieved.

It has been found that this task is in a Device of the type mentioned can be solved in a simple manner in that the bubble detector of the Bubble determination device and the hose clamp of the hose clamp close together sit and protrude from the housing box, aligned insertion slots for the hose have that the bubble detector of one in his maximum extended position lockable knee lever adjustable and the hose clamp of one in his maximum sn .. • return position lockable knee lever is releasable

Another advantageous embodiment of the invention consists in the fact that the bias determination device and the hose disconnection device are the same Brackets are equipped that carry the insertion slot for the hose on the outside and on the inside in U-shaped parts to accommodate the toggle lever run out and sit one above the other on a mounting plate, on the back of which is printed circuit boards for the Elements of the monitoring and control electronics are attached.

There are centrally located in the brackets on both sides of the insertion slots and perpendicular to these holes, which are aligned with each other as guides for both the transmitter and the receiver Bubble determination device, as well as for the clamping piece and counter bearing of the hose clamping device.

It is advantageous if in each of the parts of the bores protruding from the housing Receiver and the counter bearing can be adjusted in the axial direction by means of a thread.

A development of the invention is characterized in that in the housing-side parts of the Bores piston are arranged as a carrier for the transmitter and for the clamping piece, which in the Housing extend to the web of the I / shaped parts and are in operative connection with the toggle levers.

A further development of the invention also consists in that each knee lever consists of a long lever connected to the piston and a short, U-shaped, the free end of the long lever s enclosing actuating lever, which is at a pivot axis which can be actuated by a rotary knob is fastened in the U-shaped parts of the bracket Here tension springs bring the toggle lever parts into their extended position.

ίο The invention is also developed in that the toggle of the bladder determination device strikes in its maximum extended position against a justisranschlag and that the toggle of the hose disconnection device in the same position against a

ι s adjustment stop strikes

Here, in a further development of the invention, the U-shaped actuating lever of the hose disconnecting device goes into one below its pivot axis longer holding arm over, at which about the height

This transition is connected to a relatively strong tension spring, where m is the setting of the Hose clamp this holding arm rests against the poles of a small holding electromagnet According to a further development of the invention, the small one Holding electromagnet on the fly on a swivel axis stored

It is advantageous here if the relatively strong tension spring for the toggle lever of the hose clamping device on the hanger is its largest And exerts spring force to stretch the toggle lever into the closed position of the hose clamp when in the open position of the hose clamp the small holding electromagnet with only low Loaded by spring force

Finally, an advantageous development of the device according to the invention is that in the Circuit of the receiver of the bubble determination device an amplifier and a potentiometer for Determination of the working point of the bubble determination furnishings and their adaptation to the different chen bit hose diameter are provided.

According to the invention, all parts for the bubble determination device and for the hose clamp device can be accommodated in just one housing

• »5 will sit close together and with a large number of matching parts, for example with same brackets.

Because the parts of both brackets protruding from the housing box are aligned with one another,

thus have transverse insertion slots for the tube, the tube piece guided through the bubble determination device can also be very short.

Of particular importance, however, is the use of toggle levers both in conjunction with the Bubble determination device as well as the hose clamp device. Knee lift! are particularly suitable good for it, in the last area of your stretching movement, before reaching the stretched position, a relatively large one Contact pressure with a comfortable torque on the actuator exercise lever.

In a further development of the invention, the toggle levers and thus the bubble determination device or the hose clamping device are adjusted by means of a rotary knob. For example, you can Bring both devices into the so-called insertion position before inserting the hose into the transverse slots.

The sensible connection of the toggle lever with a spring with the aid of the adjustment stop is

it is possible that the bubble determination device is always set in operation so that the transmitter and Recipients always have the same distance from each other. To a certain extent, different Hose thicknesses are also recorded. If thicker hoses or thinner hoses are used, so the recipient of the bubble determination device within the longitudinal bore with a for provided adjusting screw can be readjusted. The spring connected to the toggle lever ensures that this in any case reaches its maximum stretched position.

When the hose clamp device is made use of the principle of construction that the whole Force that has to be used to clamp the hose from the hand with the rotary knob tensioned spring is taken over the toggle lever, whereas in the holding position (open clamp) the

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Force to be applied by the electro-magnet is there the spring practically engages in the pivot point in this position.

When the bubble determination device detects a bubble in the liquid flowing past the holding electromagnet of the hose clamping device falls away. so that the holding arm is released and under the action of the strong spring in his Extended position swivels. As a result of the toggle lever, this is a considerable one in the extended position Pressure exerted with the hose clamp so that the hose not only abruptly but also with the required force is disconnected.

Not only can the Blaseiibestimmungseinrichtung the hose clamp, but also an acoustic or optical alarm system and a Shut-down device for the feed pump must be connected.

An exemplary embodiment of the invention is described below with reference to the drawing. It shows

F i g. 1 shows a schematic overall view of the monitoring device, partly in section,

F i g. 2 a construction detail,

F i g. 3 a further construction detail and

F i g. 4 schematically shows an electrical block diagram.

In a housing box 1, a mounting plate 2 can be seen, which by means of spacers 3 and screws 4 is attached to the bottom of the housing. A printed circuit board 5 can be seen behind the mounting plate 2 which plates 6 arranged at a distance from one another are attached. On these boards or on the PCB 5 "=> nd elements 7 of a monitoring and Control electronics arranged

On the front side there is a bubble determining device 8 and in one on the assembly lath 2 A hose clamping device 9 is arranged a short distance therefrom. Both devices sit with it close to each other and parts of their brackets protrude from the housing box 1.

The bubble determination device 8 has a holder 80 with a square cross-section. A part 82 of this holder 80 protrudes from the housing box 1. In this one protruding from the case box An insertion slot 83 for the hose 10 can be seen in part 82 of the holder.

A U-shaped part 84 has a U-shaped part 84 in the housing box 1 the holder 80, which is fastened to the mounting plate 2 with screws 81

In the part of the holder 80 that protrudes furthest out of the housing box 1, a receiver 85 of a bubble detector is arranged, the transmitter 86 of which is arranged on the other cable of the insertion slot 83. The receiver 85 can be screwed into a longitudinal bore 87 in the holder. Its position relative to the insertion slot 83 can be adjusted by turning it within the thread.

The longitudinal bore 87 continues in the U-shaped part of the bracket and ends at the web of the

ίο U-shaped part 84. The U-shaped part 84 of the Bracket is penetrated by a pivot axis 88, the meaning of which will be explained later.

In Fig. 1 below the bubble determination device 8, the hose clamp device 9 is arranged. Your bracket 90 is designed in the same way externally like the holder 80 of the bubble determination device. It is also by means of screws 91 on the Mounting plate 2 attached and has one from the

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an insertion slot 93 for the tube 10 is penetrated. The insertion slots 83 and 93 are so to each other aligned that the hose 10 is easily inserted and removed. Fig. 1 shows that at Only a relatively short section of a hose 10 is used with the gas bubble determination device is needed.

The U-shaped part 94 of the holder 90 and the part 92 protruding from the housing box are from a longitudinal bore 97 penetrated. In the part of the bracket that protrudes from the housing box An abutment 95 for the hose clamp% is screwed into this longitudinal bore, the latter itself is arranged movably in the protruding into the housing box 1 part of the longitudinal bore 97.

3i The U-shaped part 94 of the bracket 90 is also from a pivot axis 98 penetrates

Pistons with toggle levers, which are shown in FIGS. 2 and 3 are shown.

According to FIG. 2, the toggle lever of the bubble determination device 8 consists of a long lever 802 which is pivotably attached by means of a pivot pin 801 within a piston 800. The piston 800 is movable in the longitudinal bore 87 of the holder

45 80 arranged By means of the pivot pin 804 , a U-shaped short actuating lever 803 is attached to the upper part of the long lever 802. The U-shaped actuating lever 803 in turn sits firmly on the pivot axis 88, which - as mentioned above, the U-shaped part 84 of the Bracket 80 penetrated On the front part of the pivot axis 88, apart from the housing box 1, a rotary knob 806 is attached, with which the toggle lever 802. 803 can be operated. If, according to FIG. 2, for example, the rotary knob 806 is turned clockwise, the piston 800 is moved in the longitudinal bore 87 in such a way that it moves away from the insertion slot 86

F i g. 2 shows that a spring 805 is attached to the long lever 802 , which is also shown in FIG. 1 is shown. This spring 805 always pulls the toggle lever 802, 803 into its extended position. Here, the U-shaped 803 proposes actuating lever at one adjustment stop 807 in the maximum extension position performs a locking of the toggle lever, it can be seen that after this defined by the adjustment stop 807 extended position the distance between the receiver 85 of the bubble detector and the transmitter 86 Screw adjustment of the receiver 85 is always the same. Minor

Differences in the outer diameter of the hose 10 can be compensated for in this way. Of the The distance set in this way between the transmitter and receiver of the bubble detector ensures reproducibility the measuring conditions and a reliable response of the bubble determining device 8.

A corresponding internal structure is also found in the hose clamp device 9 internal structure is shown in Fig.3. A piston 900 The hose clamp 96 is connected to a long lever 902 by means of a pivot pin 901 connected, the upper end of which is shown in FIG. 3 is encompassed by a U-shaped lever 903. The U-shaped one Lever 903 and the long lever 902 are connected to one another by means of a pivot pin 904. To the U-shaped lever 903 is followed by a relatively long lever arm 907, to which one also shown in FIG. 1 recognizable Spring 905 is connected.

Dci U-füiniigc new! 903 lsi to uci also li'i F i g. i recognizable pivot axis 98 mounted on the front, protruding from the housing box 1 End of a knob 906 is attached.

F i g. 3 shows the individual parts in the open position of the hose clamping device. In this position, that is the non-extended position of the toggle lever 902, 903, the holding arm 907 is under the influence of the relatively strong spring 905. By turning the rotary knob 906 clockwise, the holding arm 907 was pivoted clockwise, with the piston 900 in the longitudinal bore 97 had been moved away from the insertion slot 93. This opens the hose clamping device and the hose 10 can be inserted into the insertion slot 93 or removed from it. The pivoting of the holding arm 907 took place against the pull of the relatively strong spring 905. In the most open position of the hose clamping device, the holding arm 907 rests on the poles 14 of a small holding electromagnet 11 which is cantilevered on a pivot axis 12. When this magnet is excited, the hose clamp is locked in its open position. The winding 15 of the holding electromagnet 11 is connected to the receiver 85 of the bubble detector via control electronics. If this is excited, the winding 15 <5 of the holding electromagnet 11 is de-energized and the holding arm 907 can, following the force of the springs 95, move into its closed position, the hose iö with a relatively large force caused by the extension of the toggle lever 902, 903 is exercised. is closed.

It should be noted that the spring 905 exerts its greatest, namely the firing force or the corner force of the toggle lever 902, 903, in its non-stretched position, and that in the open position of the hose clamping device 9 according to FIG. 3 only a small force is exerted on the holding arm 907 by the spring 905 as a result of the shortened lever arm. This low holding force can easily be applied by the holding electromagnet 11.

4 schematically shows a circuit diagram for the bubble determination device. On the left of Fi g. 4 shows the blood tube 10, which is led through the bubble determination device 8 and through the hose clamp device 9 of the extended toggle lever 802, 803 and the spring 805 also rests on the blood tube 10.

In the hose clamping device 9, the hose 10 rests against the abutment 95 of the hose clamp, but the hose clamp% itself is in its “open” position. This means that the toggle lever 902, 903 is not in its extended position, but that the holding arm 907 rests against the poles of the electromagnet 11. The holding arm 907 is further under the influence of the relatively strong spring 905, which - as shown in FIG. 4 can also be seen - the holding magnet 11 is hardly loaded. The holding magnet 11 is shown as if it were energized, but the further circuit is shown in a de-energized state in accordance with the usual representation.

The transmitter 86 of the bubble detector receives pulses

üuci 'a ocnucVcfäiiif Κ6Γ 1 / Zügciüiifi. u / ci 'LiTipiän ger 85 of the gas detector is connected via a receiver amplifier 18 to a line 20 which is fed by a balancing device 19, with which different hose thicknesses can be compensated to a certain extent and the working point of the arrangement can be determined.

The line 20 leads to a relay 22, the relay contact 222 of which is connected as an opener. The administration 20 continues to lead to the winding 15 of the electromagnet 11. The devices in the indicated housing box 1 of the bubble determination device are also only indicated via electrical lines with a Hemodialysis machine 28 connected. The figure also shows that the voltage supply of the Bubble determination device is connected to the hemodialysis machine 28.

In the alarm circuit shown schematically, an optical alarm transmitter 23 and an acoustic alarm transmitter 24 are provided. Furthermore, a switching protection 26 with closing contacts for a blood pump 27 is located in the line. A limit switch 25 is provided in the circuit of the switching protection 76 and is connected as an opener. The limit switch 25 is switched by the holding arm 907 when it strikes against a stop 21 after the electromagnet 11 has dropped.

When the circuit arrangement according to FIG. 4 is connected to voltage, the relay contact 222 is open and the closing contacts of the switching protection 26 are closed. The electromagnet 11 is energized and holds that End of the holding arm 907 firmly. The blood pump works in this state.

When normal blood flows through the tube 10, the circuit remains in the indicated state.

If, however, foam forms in the blood or an accumulation of air bubbles occurs, the reception of the receiver 85 of the bubble detector is disturbed. If a certain amount of bubbles is present in the blood, the receiver 85 and thus also the amplifier 18 emits a signal. The relay 22 drops out and the relay contact 222 closes. This triggers acoustic and visual alarms by the alarm transmitters 23 and 24, respectively. After the electromagnet 11 has also fallen off, the holding arm 907 follows the force of the spring 905 until the holding arm 907 rests against the stop 21

If the leading to gas or bubble formation Damage during hemodialysis can be repaired

Bubble determination device again in the in Fig.4 can be reset. Turning the rotary knob 906 clockwise will the extension of the toggle lever 902, 903 is canceled and the holding arm 907 is again in operative contact with the poles of the electromagnet 11 brought. After closing the limit switch 25 and energizing the relay 22 is again the in F i g. 4 shown switching state before.

For this purpose 3 sheets of drawings

Claims (11)

Patent claims: 1. Device for monitoring venous blood Gas bubbles flowing through a hose behind a hemodialysis machine, with a housing box for elements of the monitoring * - and Control electronics, in which at the same time a bubble determination device with a bubble detector and a hose disconnection device connected therewith are arranged, the hose clamp of which in the presence of bubbles clamps the hose, characterized in that the bubble detector (85, 86) ider Bubble determination device (8) and the hose clamp (95, 96) of the hose clamp device 5 (9) sit close together and protrude from the housing box, have aligned insertion slots (83,93) for the hose (10) that the bubble detector (85, 86) by a knee lever that can be locked in its maximum stretching position (8Ü2, SiB) and the hose clamp (55, 96) can be released by a toggle lever (902, 903) that can be locked in its maximum extended position 2. Apparatus according to claim 1, characterized in that the Blaseiobestimmungseinrichtung (8) and the hose disconnection device (9) are equipped with the same brackets (80, 90) that have the insertion slots (83, 93) on the outside for the hose (10) wear and on the inside in U-shaped parts (84,94) rare The toggle lever (800, 801, 802, 803, 8IM; 900, 901, OT2, 903, 904) run out and the Sit one above the other on a mounting plate (2), on the back of which there are printed circuit boards (5,6) for the elements (7) the monitoring and control electronics are attached. 3. Device according to one of claims 1 and 2, characterized in that it is centered in the Brackets (80, 90) on both sides of the insertion slots and perpendicular to these holes (87, 97), which are aligned with one another as * o Guides for both the transmitter (86) and receiver (85) of the bubble determination device (8), as well as for the clamping piece (96) and counter bearing (95) of the hose clamping device (9) serve. 4. Device according to one of claims 1-3, characterized in that in the out of the housing protruding parts (82, 92) of the bores (87, 97) each of the receiver (85) and the counter-ligature (95) by means of a thread in the axial direction are adjustable. 5. Device according to one of claims 1-4, characterized characterized in that in the housing-side parts of the bores (87,97) piston (800,900) as a carrier for the transmitter (86) and for the clamping piece (96) are arranged, which extend in the housing to the web of the U-shaped parts (84, 94) and with the toggle levers (801, 802, 803, 804; 901, 902, 903, 904) are in operative connection. 6. Device according to one of claims 1-5, characterized & o characterized in that each toggle lever consists of a long lever connected to the piston (800,900) (802, 902) and a short, U-shaped actuating lever (803,903) enclosing the free end of the long lever, which is attached to a van a rotary knob (806, 906) actuatable pivot axis (88, 98) in the U-shaped parts (84, 94) of the Brackets (80,90) is attached 7. Device according to one of claims 1-6, characterized by tension springs (805, 905) which the Toggle lever parts (802,803; 902,903) in their stretched Take position. JL device according to one of claims 1-7, characterized characterized in that the toggle lever (802, 803) of the Bladder determination device (8) in its maximum stretched position against an adjustment stop (807) strikes and that the toggle lever (902, 903) of the Hose clamping device (9) strikes against an adjustment stop (21) in the same position 9. Device according to one of claims 1-8, characterized in that the U-shaped actuating lever (903) of the hose clamping device (9) merges below its pivot axis (98) into a longer holding arm (907), on which approximately at the level of this transition a relatively strong tension spring (90S) is connected, and that in the open control of the hose clamping device (9) this holding arm (907) rests against the poles (14) of a small Haiie electromagnet (i i) 10. Device according to one of claims 1-9, characterized in that the small holding electromagnet (11) overhung on a pivot axis (12) is stored 11. Device according to one of claims 1 - 10, characterized in that the relatively strong tension spring (905) for the toggle lever (902, 903) of the hose clamping device (9) on the holding arm (907) its greatest spring force for stretching the Exercises toggle lever in the closed position of the hose clamp (95, 96) and that it is in the The open position of the hose clamp (95, 96) loads the small holding electromagnet (11) with only a small spring force IZ device according to one of claims 1 - 11, characterized in that in the circuit of the receiver of the bubble determination device (8) an amplifier (18) and a potentiometer (19) to determine the operating point of the bubble determination device (8) and to adapt it to the different blood tube diameters are provided.