Blood leakage sensor capable of reducing false alarm and continuous blood evolution system

Abstract

The blood leakage sensor comprises a blood leakage sensor body and a cover body, the blood leakage sensor body comprises a shell, a clamping groove for clamping a pipeline is formed in the top end of the shell, an opening is formed in the position, located at the clamping groove, of the outer wall of the shell, and the cover body is arranged on the outer wall of the shell. A bubble sensor used for detecting bubbles in a pipeline and a blood leakage sensor used for detecting blood permeation in the pipeline are arranged at the opening, the bubble sensor is arranged at the front end of the blood leakage sensor and serves as a front detection unit, and the cover body is hinged to a blood leakage sensor body and can be opened or closed relative to the blood leakage sensor body. The bubble sensor is integrated in the blood leakage sensor, and the bubble sensor is arranged at the front end of the blood leakage sensor, so that bubbles and blood can be more accurately distinguished, the false alarm condition of the blood leakage sensor caused by bubble misjudgment is reduced, the smooth proceeding of the dialysis process is ensured, and the safety and efficiency of dialysis treatment are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a blood leakage sensor capable of reducing false alarms and a continuous blood purification system. Background Art

[0002] When using a hemodialysis device to treat a patient, the hemodialysis device introduces the patient's blood into the hemodialysis machine pipeline, and after purification, the blood is reinfused into the patient's body. During the whole treatment process, the hemodialysis membrane may be broken due to excessive pressure, resulting in blood leakage. If the hemodialysis membrane breaks during the operation of the hemodialysis device, the patient's blood will flow from the blood chamber of the hemodialysis device into the dialysate chamber, and then enter the interior of the device along with the dialysate, causing pollution. If the membrane breakage cannot be detected and measures are not taken in time, it will endanger the patient's life safety. Therefore, blood leakage detection is particularly important during the operation of the hemodialysis machine.

[0003] Currently, the blood leakage sensors on the market are basically optoelectronic sensors, which judge whether the membrane breakage occurs by detecting whether there is heme in the liquid pipeline of the hemodialysis device. When the membrane breakage occurs, a small amount of blood flows into the dialysate and is quickly diluted, and the dialysate in the pipeline will change color very slightly. The blood leakage sensor can sense the property of the liquid in the replacement liquid pipeline. If the liquid changes from colorless and transparent to blood with a certain concentration, the sensor will give an alarm, so that medical staff such as nurses can know the occurrence of this situation and take corresponding measures in time.

[0004] As Figure 7 shown, in the prior art, the blood leakage sensor in the hemodialysis device usually works based on the optical principle. This sensor detects the presence of blood by detecting the light absorption or scattering characteristics of the blood sample. When blood flows through the sensor, it will change the reflection or absorption characteristics of light. The photodetector in the sensor will detect these changes to judge whether there is blood. If the hemodialysis device is not pre-filled completely, air bubbles will appear in the waste liquid circuit. When the air bubbles pass through the blood leakage sensor, the air bubbles will change the reflection or absorption characteristics of light, resulting in the signal detected by the sensor being similar to the signal when blood leaks, affecting the light flux detected by the sensor, and thus triggering a false alarm of the blood leakage sensor. Or, the air bubbles may interfere with the propagation path of light in the sensor, resulting in a change in the optical signal received by the sensor, thus causing a false alarm of the blood leakage sensor, which affects the normal treatment process. In addition, after a false alarm, the treatment will be interrupted, and medical staff need to check the false alarm and then restart the treatment, which also increases the workload of medical staff maintenance. Content of the Utility Model

[0005] In order to solve the above problems existing in the prior art, the purpose of the present utility model is to provide a blood leakage sensor and a continuous blood purification system that can reduce false alarms. A bubble sensor is integrated in the blood leakage sensor, and the bubble sensor is arranged at the front end of the blood leakage sensor, which can more accurately distinguish bubbles and blood, reduce the false alarm of the blood leakage sensor caused by misjudgment of bubbles, and improve the safety and efficiency of dialysis treatment.

[0006] In order to solve the above technical problems, the technical solution adopted by the present utility model is as follows: A blood leakage sensor that can reduce false alarms, including:

[0007] A blood leakage sensor body, including a housing, a clamping groove for clamping a pipeline is arranged at the top end of the housing, an opening is arranged on the outer wall of the housing at the position of the clamping groove, a bubble sensor for detecting whether there are bubbles in the pipeline and a blood leakage sensor for detecting blood penetration in the pipeline are arranged at the opening, and the bubble sensor is arranged at the front end of the blood leakage sensor as a pre-detection unit;

[0008] A cover body, hinged to the blood leakage sensor body, can be opened or closed relative to the blood leakage sensor body.

[0009] As a further improvement of the present utility model, both the transmitting end and the receiving end of the bubble sensor extend outward into the clamping groove after passing through the opening, and both the light emitter and the light receiver of the blood leakage sensor extend outward into the clamping groove after passing through the opening.

[0010] As a further improvement of the present utility model, a first mounting ear is connected to the bottom of the blood leakage sensor, and a mounting seat adapted to the mounting ear is arranged inside the housing.

[0011] As a further improvement of the present utility model, a base is connected to the bottom of the housing, and a microswitch assembly for detecting whether there is a pipeline installed in the blood leakage sensor body is also arranged inside the housing;

[0012] The microswitch assembly includes a pressing block and a microswitch. One end of the pressing block penetrates through the bottom of the clamping groove and extends outward into the clamping groove, and the other end of the pressing block is in contact with the moving contact of the microswitch. The microswitch is fixed on the base through a second fixing block;

[0013] Wherein, when the pipeline is clamped in the clamping groove, the pressing block moves towards the direction of the moving contact of the microswitch, so that the moving contact of the microswitch is connected to the fixed contact of the microswitch; when there is no pipeline in the clamping groove, the pressing block moves away from the direction of the moving contact of the microswitch, so that the moving contact of the microswitch is separated from the fixed contact of the microswitch.

[0014] As a further improvement of the present utility model, the cover body includes a top cover, a connecting block arranged at the bottom of the top cover, and a fastener arranged on the connecting block;

[0015] Wherein, when the cover body is closed, the fastener locks the cover body and the blood leakage sensor body.

[0016] As a further improvement of the present utility model, the fastener includes an adjusting screw rod and a top bead connected to the tail of the adjusting screw rod. The head of the adjusting screw rod passes through a threaded hole provided on the connecting block and is threadedly connected to the connecting block. A fastening groove adapted to the top bead is provided on the outer wall of the housing, and a notch is provided at the head of the adjusting screw rod.

[0017] As a further improvement of the present utility model, a pressing column for pressing the pipeline is further provided at the bottom of the top cover.

[0018] As a further improvement of the present utility model, connecting ears are provided at both ends of the base, and connecting holes are provided on the connecting ears.

[0019] The present utility model also protects a continuous blood purification system, including:

[0020] A blood leakage sensor capable of reducing false alarms;

[0021] An arterial side blood circuit, a filter, an exhaust chamber, and a venous side blood circuit connected in sequence. A blood pump is provided on the arterial side blood circuit. A second bubble sensor and a venous clamp are sequentially provided on the venous side blood circuit and on the pipeline at the rear end of the exhaust chamber. One side outlet of the filter is connected to a waste liquid circuit, a waste liquid pump is provided on the waste liquid circuit, and the blood leakage sensor body is provided on the waste liquid circuit at the rear end of the waste liquid pump;

[0022] It further includes a control system. The blood leakage sensor and the second bubble sensor are respectively electrically connected to the input end of the control system, and the venous clamp and the blood pump are respectively electrically connected to the output end of the control system. When the bubble sensor detects bubbles in the waste liquid circuit, the control system performs signal filtering, and the blood leakage sensor does not trigger an alarm. When there is blood penetration in the pipeline, the blood leakage sensor triggers an alarm.

[0023] Compared with the prior art, the present utility model has the following beneficial effects:

[0024] A blood leakage sensor capable of reducing false alarms of the present utility model integrates a bubble sensor in the blood leakage sensor and arranges the bubble sensor at the front end of the blood leakage sensor, which can more accurately distinguish bubbles and blood, reduce the false alarm situation of the blood leakage sensor caused by misjudgment of bubbles, ensure the smooth progress of the dialysis process, and improve the safety and efficiency of dialysis treatment. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the overall structure of a blood leakage sensor capable of reducing false alarms of the present utility model;

[0026] Figure 2 Side view structural schematic diagram of a blood leakage sensor capable of reducing false alarms according to the present utility model;

[0027] Figure 3 Schematic diagram of the cover body of a blood leakage sensor capable of reducing false alarms according to the present utility model being opened;

[0028] Figure 4 Internal structural schematic diagram of the housing of a blood leakage sensor capable of reducing false alarms according to the present utility model;

[0029] Figure 5 Schematic diagram of the cover body structure of a blood leakage sensor capable of reducing false alarms according to the present utility model;

[0030] Figure 6 Structural block diagram of a continuous blood purification system according to the present utility model;

[0031] Figure 7 Principle block diagram of a prior art blood leakage sensor. Specific embodiments

[0032] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0033] Figures 1 to 6 The figure shows a structural schematic diagram of an embodiment of a blood leakage sensor capable of reducing false alarms according to the present utility model, and its main part includes a blood leakage sensor body 100 and a cover body 200.

[0034] The blood leakage sensor body 100 includes a housing 110 and a base 120. The housing 110 has an accommodation space inside. The bottom of the housing 110 is open. A clamping groove 110a for clamping the waste liquid circuit of the blood purification device is provided at the top of the housing 110. An opening 110c is provided on the outer wall of the housing 110 at the position of the clamping groove 110a. A bubble sensor 130 for detecting air bubbles in the pipeline and a blood leakage sensor 140 for detecting blood penetration in the pipeline are sequentially provided at the opening 110c, and the bubble sensor 130 is located at the front end of the blood leakage sensor 140. As Figure 6As described above, in this embodiment, the blood leakage sensor body 100 is connected to the waste liquid discharge circuit of the filter (on the waste liquid circuit 9) to monitor whether there is damage to the semipermeable membrane of the filter. An installation ear 140a is connected to the bottom of the blood leakage sensor 140, and an installation seat 110d adapted to the installation ear 140a is provided inside the housing 110.

[0035] In this embodiment, the blood leakage sensor 140 is a photoelectric sensor that detects blood leakage by monitoring the change in light intensity caused by blood in the waste liquid. A bubble sensor 130 is integrated in the blood leakage sensor body 100, and the bubble sensor 130 is arranged at the front end of the blood leakage sensor 140. The bubble sensor 130 is kept at a certain distance from the blood leakage sensor 140, which can ensure that the bubble sensor 130 has enough time to send a signal and trigger the control system to start the signal filtering mechanism. Thus, before the blood leakage sensor 140 is affected, the system is already ready to ignore or reduce the response to the bubble signal, so as to ensure that the blood leakage sensor 140 has enough feedback time and can still maintain a high detection accuracy under the influence of bubbles. The bubble sensor 130, as a pre-detection unit, first detects whether there are bubbles in the waste liquid circuit. If bubbles are detected, a signal is sent to the control system of the blood purification device, indicating that the subsequent signal change may be caused by bubbles, thereby controlling the start of a signal filtering mechanism to ignore or reduce the influence on the subsequent signals of the blood leakage sensor 140, so as to avoid misjudging the signal change caused by bubbles as blood leakage. The integrated bubble sensor 130 is specifically used to detect the presence of bubbles, and can also further combine algorithms or other mechanisms to distinguish the signal changes caused by bubbles and blood, thereby reducing false alarms. For example, by analyzing the characteristics such as the duration and recovery speed of the signal change, the signal change that is short and quickly recovers is determined as the passage of bubbles, while the continuous signal change is determined as blood leakage. When the bubble sensor 130 detects bubbles, the control system can delay the alarm threshold of the blood leakage sensor 140 until it is confirmed that the signal change is not caused by bubbles. At the same time, on the device user interface, the system can provide a prompt to inform the medical staff that the current signal change may be caused by bubbles, so as to avoid unnecessary intervention before confirming blood leakage. The blood leakage sensor 140 monitors the blood leakage situation in the blood purification device in real time to ensure that once blood leakage occurs during dialysis, it can be detected immediately. When the semipermeable membrane of the filter is damaged and blood overflows, the blood leakage sensor 140 will give an alarm in time to ensure the safety of the patient during the treatment process.

[0036] Preferably, in this embodiment, the central axes of the bubble sensor 130 and the blood leakage sensor 140 coincide with the central axis of the card slot 110a, so that the transmitting end and the receiving end of the bubble sensor 130 and the light emitter and the light receiver of the blood leakage sensor 140 are symmetrically distributed on both sides of the waste liquid circuit, further improving the detection accuracy.

[0037] Both the transmitting end and the receiving end of the bubble sensor 130 extend outward into the card slot 110a after passing through the opening 110c. Both the light emitter and the light receiver of the blood leakage sensor 140 extend outward into the card slot 110a after passing through the opening 110c. When the pipeline is placed in the card slot 110a, the transmitting end and the receiving end of the bubble sensor 130 and the light emitter and the light receiver of the blood leakage sensor 140, which protrude from the opening 110c, are closely attached to the outer wall of the pipeline, so as to accurately detect the bubble condition in the pipeline.

[0038] Preferably, in this embodiment, a microswitch assembly 300 for detecting whether a pipeline is installed in the blood leakage sensor body 100 is further provided in the housing 110. Specifically, the microswitch assembly 300 includes a pressing block 310 and a microswitch 320. One end of the pressing block 310 passes through the bottom of the card slot 110a and extends outward into the card slot 110a. The other end of the pressing block 310 is in contact with the moving contact of the microswitch 320. The microswitch 320 is fixed on the base 120 through a second fixing block 330. Wherein, when the pipeline is clamped in the card slot 110a, the pressing block 310 moves towards the direction of the moving contact of the microswitch 320, so that the moving contact of the microswitch 320 is connected to the fixed contact of the microswitch 320. When there is no pipeline in the 110a, the pressing block 310 moves away from the moving contact of the microswitch 320, so that the moving contact of the microswitch 320 is separated from the fixed contact of the microswitch 320. Thus, by driving the moving contact and the fixed contact of the microswitch 320 to be connected or separated through the pressing block 310, it is possible to quickly identify whether a pipeline is installed in the blood leakage sensor body 100.

[0039] The cover body 200 is used to cover the top of the blood leakage sensor body 100 and can be opened or closed relative to the blood leakage sensor body 100 to prevent the pipeline from slipping out of the card slot 110a. At the same time, it can also reduce the influence of environmental light change on the measurement of the color sensor. The cover body 200 is hinged to the blood leakage sensor body 100 through a hinge block 240 provided on the top of the sensor body 100. Specifically, the cover body 200 includes a top cover 210, a connecting block 220 provided at the bottom of the top cover 210, and a fastening member 230 provided on the connecting block 220. The connecting block 220 is provided on the side away from the hinge section. When the cover body 200 is closed, the fastening member 230 locks the cover body 200 to the blood leakage sensor body 100. Specifically, the fastening member 230 includes an adjusting screw 230a and a top bead 230b connected to the tail of the adjusting screw 230a. The head of the adjusting screw 230a passes through a threaded hole provided on the connecting block 220 and is threadedly connected to the connecting block 220. A fastening groove 110b adapted to the top bead 230b is provided on the outer wall of the housing 110, and a notch is provided at the head of the adjusting screw 230a. During use, push the end of the top cover 210 connected to the connecting block 220. When the top cover 210 is parallel to the top of the housing 110, at this time, the top bead 230b is located in the fastening groove 110b, and the top cover 210 and the housing 110 are locked.

[0040] Preferably, in this embodiment, in order to adjust the tightness of the fastening member 230, an adjusting cover 220a is provided on the outer wall of the connecting block 220 near the head of the adjusting screw 230a. When adjustment is required, open the adjusting cover 220a, and the notch at the head of the adjusting screw 230a can be rotated by a wrench, so as to adjust the distance between the top bead 230b and the fastening groove 110b, thereby adjusting the tightness of the fastening member 230, and thus adjusting the fastening degree between the cover body 200 and the blood leakage sensor body 100 to prevent the pipeline from slipping out of the card slot 110a. When the adjustment is completed, cover the adjusting cover 220a again. In addition, in order to prevent the pipeline from being bent and improve the detection accuracy, a pressing column 250 for pressing the pipeline is further provided at the bottom of the top cover 210. When the pipeline is placed in the card slot 110a, the end of the pressing column 250 fits against the outer wall of the pipeline to limit the pipeline. The bottom of the pressing column 250 is spherical to reduce damage to the pipeline. The pressing columns 250 can be provided in multiple numbers along the length directions of the card slot 110a and the pipeline according to actual needs. Connecting ears 120a are provided at both ends of the base 120, and connection holes are provided on the connecting ears 120a. Through the connecting ears 120a, the base 120 is fixed to the front end of the blood purification device.

[0041] As Figure 6As shown in the figure, the present utility model also protects a continuous blood purification system, which includes a blood leakage sensor, an arterial side blood circuit 2, a filter 3, an air exhaust chamber 4, and a venous side blood circuit 5 that are connected in sequence. A blood pump 6 is provided on the arterial side blood circuit 2. A second bubble sensor 7 and a venous clamp 8 are sequentially provided on the venous side blood circuit 5 and on the pipeline behind the air exhaust chamber 4. One side outlet of the filter 3 is connected to a waste liquid circuit 9, and a waste liquid pump 10 is provided on the waste liquid circuit 9. The blood leakage sensor body 100 is provided on the waste liquid circuit 9 behind the waste liquid pump 10. It also includes a control system. The blood leakage sensor 140 and the second bubble sensor 7 are respectively electrically connected to the input end of the control system. The venous clamp 8 and the blood pump 6 are respectively electrically connected to the output end of the control system. When the bubble sensor 130 detects bubbles in the waste liquid circuit 9, the control system performs signal filtering, and the blood leakage sensor 140 does not trigger an alarm. When there is blood penetration in the pipeline, the blood leakage sensor 140 triggers an alarm. During the use of the system, the bubble sensor 130 in the blood leakage sensor of the present utility model serves as a pre-detection unit. When it detects bubbles in the waste liquid circuit 9, it sends a signal to the control system of the blood purification equipment. The control system starts a signal filtering mechanism according to this signal to ignore or reduce the influence on the signal of the subsequent blood leakage sensor 140, and avoid misjudging the signal change caused by bubbles as blood leakage. It reduces the false alarms of the blood leakage sensor caused by misjudgment of bubbles, ensures the smooth progress of the dialysis process, and medical staff do not need to frequently check and clean the sensor due to false alarms, thereby reducing the maintenance requirements and workload.

[0042] In this embodiment, the second bubble sensor 7 is integrated with a color sensor for detecting the color of the fluid in the pipeline of the venous side blood circuit 5. The second bubble sensor 7 feeds back the detected signal to the system host, thereby controlling the operation of the blood pump 6 and the venous clamp 8. The second bubble sensor 7 real-time detects the bubbles and the color change of the liquid in the venous side blood circuit 5. When it detects bubbles in the venous side blood circuit 5, the control system controls the venous clamp 8 to clamp the pipeline. When the detected color is transparent, it indicates that the blood has been completely transfused back, and a transparent color signal is sent to the control system to control the blood pump 6 to stop running, preventing excessive physiological saline from being input into the human body.

[0043] Although the present utility model has been described above with reference to the embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present utility model. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed by the present utility model can be combined with each other in any way. The exhaustive description of these combinations is not given in this specification only for the consideration of saving space and resources. Therefore, the present utility model is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A blood leakage sensor capable of reducing false alarms, characterized in that: include: A blood leakage sensor body (100) comprises a housing (110), wherein a slot (110a) for clamping a pipeline is provided at the top of the housing (110), an opening (110c) is provided on the outer wall of the housing (110) and located at the slot (110a), a bubble sensor (130) for detecting whether bubbles exist in the pipeline and a blood leakage sensor (140) for detecting blood penetration in the pipeline are provided at the opening (110c), and the bubble sensor (130) is provided at the front end of the blood leakage sensor (140) as a front detection unit; The cover body (200) is hinged to the blood leakage sensor body (100) and can be opened or closed relative to the blood leakage sensor body (100).

2. A blood leakage sensor capable of reducing false alarms according to claim 1, characterized in that: include: The transmitting end and the receiving end of the bubble sensor (130) both pass through the opening (110c) and extend outwards into the card slot (110a), and the light transmitter and the light receiver of the blood leakage sensor (140) both pass through the opening (110c) and extend outwards into the card slot (110a).

3. The blood leakage sensor capable of reducing false alarms according to claim 1, characterized in that: include: The bottom of the blood leakage sensor (140) is connected to a mounting ear (140a), and the interior of the housing (110) is provided with a mounting seat (110d) adapted to the mounting ear (140a).

4. A blood leakage sensor capable of reducing false alarms according to any one of claims 1 to 3, characterized in that: The bottom of the housing (110) is connected to a base (120), and a micro switch assembly (300) for detecting whether a pipeline is installed in the blood leakage sensor body (100) is also arranged in the housing (110); The micro switch assembly (300) comprises a pressing block (310) and a micro switch (320), one end of the pressing block (310) passes through the bottom of the card slot (110a) and extends outward into the card slot (110a), the other end of the pressing block (310) contacts the moving contact of the micro switch (320), and the micro switch (320) is fixed on the base (120) via a second fixing block (330); When the pipeline is clamped in the slot (110a), the pressing block (310) moves in a direction close to the moving contact of the micro switch (320), so that the moving contact of the micro switch (320) is connected with the fixed contact of the micro switch (320); when there is no pipeline in the slot (110a), the pressing block (310) moves in a direction away from the moving contact of the micro switch (320), so that the moving contact of the micro switch (320) is separated from the fixed contact of the micro switch (320).

5. The blood leakage sensor capable of reducing false alarms according to claim 1, characterized in that: The cover body (200) comprises a top cover (210), a connection block (220) arranged at the bottom of the top cover (210), and a fastener (230) arranged on the connection block (220); When the cover body (200) is closed, the fastener (230) locks the cover body (200) and the blood leakage sensor body (100).

6. The blood leakage sensor capable of reducing false alarms according to claim 5, characterized in that: The fastener (230) comprises an adjusting screw (230a) and a top ball (230b) connected to the tail of the adjusting screw (230a); the head of the adjusting screw (230a) passes through a threaded hole (220b) provided on the connecting block (220) and is threadedly connected to the connecting block (220); a fastening groove (110b) adapted to the top ball (230b) is provided on the outer wall of the housing (110); and a notch is provided on the head of the adjusting screw (230a).

7. The blood leakage sensor capable of reducing false alarms according to claim 5, characterized in that: A compression column (250) for compressing the pipeline is also provided at the bottom of the top cover (210).

8. The blood leakage sensor capable of reducing false alarms according to claim 6, characterized in that: An adjustment cover (220a) is provided on an outer wall of one side of the connection block (220) close to the head of the adjustment screw rod (230a).

9. The blood leakage sensor capable of reducing false alarms according to claim 4, characterized in that: Both ends of the base (120) are provided with connecting ears (120a), and both connecting ears (120a) are provided with connecting holes.

10. A continuous blood evolution system, characterized in that: include: A blood leakage sensor capable of reducing false alarms as described in any one of claims 1 to 9; An arterial blood circuit (2), a filter (3), an exhaust chamber (4) and a venous blood circuit (5) are sequentially connected, the arterial blood circuit (2) is provided with a blood pump (6), a second bubble sensor (7) and a venous clamp (8) are sequentially provided on the venous blood circuit (5) and on the rear end pipeline of the exhaust chamber (4), one side outlet of the filter (3) is connected to a waste liquid circuit (9), a waste liquid pump (10) is provided on the waste liquid circuit (9), and the blood leakage sensor body (100) is provided on the waste liquid circuit (9) at the rear end of the waste liquid pump (10); The device also includes a control system, wherein the blood leakage sensor (140) and the second bubble sensor (7) are electrically connected to the input end of the control system respectively, and the venous clamp (8) and the blood pump (6) are electrically connected to the output end of the control system respectively. When the bubble sensor (130) detects bubbles in the waste liquid circuit (9), the control system performs signal filtering, and the blood leakage sensor (140) does not trigger an alarm. When blood penetrates into the pipeline, the blood leakage sensor (140) triggers an alarm.

Images