blood purification device

Abstract

The present invention is configured to not drive the blood pump until the puncture needle is removed. The blood purification device includes a blood circuit, a blood pump, a needle removal detection unit, and a control unit. The blood circuit is connected to the puncture needle inserted into the patient and allows blood from the patient to flow. The blood pump is disposed in the blood circuit and is driven to transport the liquid within the blood circuit. The needle removal detection unit detects when the puncture needle has been removed from the patient, and the control unit initiates a blood return process to return the blood within the blood circuit to the patient. In response to determining that the blood return process has ended, the blood pump is set to an inoperative state.

Description

Technical Field

[0001] The present disclosure relates to a blood purification device. Background Art

[0002] If the kidneys, which are part of the human body's internal organs, no longer function properly (renal failure), their functions of converting excess water into urine and excreting unnecessary metabolites from the body will no longer be able to function. To treat renal failure, a blood purification device (dialysis device) is used to circulate blood from the patient outside the body and filter waste and water from the blood using a blood purifier (dialysis treatment).

[0003] The blood purification device draws blood from the patient and introduces the blood into the blood purifier (blood flow path) through a blood circuit. Furthermore, dialysate is introduced from a dialysate supply source (dialysate supply unit) through a dialysate circuit into the blood purifier (dialysate flow path). The blood purification device then purifies the blood by exchanging metabolites, electrolytes, and other components between the blood and the dialysate via the blood purifier, and returns the purified blood to the body.

[0004] After blood is introduced into the blood circuit during dialysis treatment, some blood remains in the blood circuit. Therefore, a step (blood return process) is generally performed by flowing physiological saline or dialysate into the blood circuit to return the remaining blood to the body. This blood return process is performed by driving a blood pump installed in the blood circuit to pump the liquid in the circuit. Summary of the Invention

[0005] Typically, after the blood return process is complete, the blood pump may be activated in a subsequent process. For example, a subsequent process may be a drainage process to remove dialysate remaining in the blood circuit. During the drainage process, the blood pump must be activated after the puncture needle has been removed from the patient. If the blood pump is activated after the blood return process is complete and the puncture needle is not removed, there is a risk of air being introduced into the body or of further blood and water removal.

[0006] The present embodiment aims to provide a blood purification apparatus configured not to drive a blood pump until the puncture needle is removed after the blood return process is completed.

[0007] The blood purification device of the embodiment includes: a blood circuit, which is connected to a puncture needle inserted into a patient, and blood from the patient flows in the blood circuit; a blood pump, which is arranged in the above-mentioned blood circuit and transports the liquid in the above-mentioned blood circuit by being driven; a needle removal detection unit, which detects that the above-mentioned puncture needle has been removed from the above-mentioned patient; and a control device, which starts a blood return process to return the blood in the above-mentioned blood circuit to the patient, and in response to determining that the above-mentioned blood return process has ended, sets the above-mentioned blood pump to a non-working state.

[0008] Another embodiment of the method relates to a method implemented by a blood purification device, wherein the blood purification device includes a blood circuit, a blood pump and a needle removal detection unit, the blood circuit is connected to a puncture needle punctured into a patient, blood from the patient flows in the blood circuit, the blood pump is arranged in the blood circuit, and is driven to transport the liquid in the blood circuit, and the needle removal detection unit detects that the puncture needle has been removed from the patient. The method includes: a step of detecting that the puncture needle has been removed, a step of initiating a blood return process to return the blood in the blood circuit to the patient, and a step of setting the blood pump to a non-working state in response to a determination that the blood return process has ended.

[0009] According to the blood purification apparatus of the embodiment, it is possible to prevent the blood pump from being driven with the puncture needle still in the state where it is not removed after the blood return step is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A piping diagram showing the structure of the blood purification device according to the first embodiment;

[0011] Figure 2 A diagram showing the relationship between the needle removal detection unit, electrodes, and a control device;

[0012] Figure 3 A diagram showing the relationship between the state mode and the operating state of the blood pump;

[0013] Figure 4 It is a diagram showing the flow of the dialysate in the dialysate introduction phase according to the first embodiment.

[0014] Figure 5 1 is a diagram showing the flow of dialysate and air during the air introduction phase of the first embodiment;

[0015] Figure 6 A diagram showing the flow of drainage in the drainage process;

[0016] Figure 7 is a flowchart showing the processing of the first embodiment;

[0017] Figure 8 A piping diagram showing the structure of a blood purification device according to a second embodiment;

[0018] Figure 9 A piping diagram showing the structure of a blood purification device according to a second embodiment;

[0019] Figure 10 A piping diagram showing the structure of a blood purification device according to a second embodiment;

[0020] Figure 11 FIG. 1 is a diagram showing the flow of the dialysate during the dialysate introduction phase according to the second embodiment;

[0021] Figure 12 1 is a diagram showing the flow of dialysate and air during the air introduction phase of the second embodiment;

[0022] Figure 13 1 is a diagram showing the flow of dialysate and air during the air introduction phase of the second embodiment;

[0023] Figure 14 It is a diagram showing the configuration of a needle removal detector and a puncture needle according to a third embodiment. DETAILED DESCRIPTION

[0024] The following describes an embodiment of a blood purification device with reference to the accompanying drawings. The blood purification device of the embodiment prevents the blood pump provided in the blood circuit from being driven while the puncture needle is still in place, during the blood return process performed at the end of dialysis treatment, hemofiltration dialysis treatment, etc. The blood return process is performed by introducing dialysate into the blood circuit and then introducing air, thereby squeezing any blood remaining in the blood circuit out of the body.

[0025] <First embodiment>

[0026] First, the first embodiment will be described. In the first embodiment, an example of performing a blood return process after dialysis (HD), a chronic blood purification therapy, for chronic renal failure, etc. will be described. Dialysis is merely an example of a chronic blood purification therapy, and this embodiment is also applicable to hemofiltration (HF) and hemodialysis filtration (HDF).

[0027] Figure 1The piping diagram of the structure of the blood purification device 100 of the first embodiment is shown. The blood purification device 100 includes a blood circuit 1, a blood purifier 2, an air introduction part 3, a needle removal detection part 4, a blood concentration detection part 5 (in this embodiment, blood concentration detection parts 5a and 5b), a bubble detection part 6 (in this embodiment, bubble detection parts 6a and 6b), a dialysate introduction line IL, a drainage line EL, a pre-filled liquid line PL, a water removal line RL, a bypass line BL (in this embodiment, bypass lines BL1 and BL2), a blood pump P1, a compound pump P2, a water removal pump P3, a dialysate supply part DS, a dialysate filter DF (in this embodiment, dialysate filters DF1 and DF2), a power supply PS, an electrode EPa, an electrode EPb, an electrode EPc, and a control device C. These components are merely illustrative and may also be included in other components not shown in the figure. In addition, for example, some components such as the blood concentration detection part 5 and the bubble detection part 6 are not essential components.

[0028] The blood circuit 1 is a flow path that guides blood removed from the patient P into the blood purifier 2 during dialysis treatment, and returns the blood (purified blood) removed from the blood purifier 2 back to the body. The blood circuit 1 is mainly composed of a tube that allows the passage of dialysate and blood. Blood flows from a blood removal puncture needle RN inserted into the blood removal side (artery) of the patient P to a blood return puncture needle AN inserted into the blood return side (vein) of the patient P. The blood circuit 1 includes a blood removal circuit 1a and a blood return circuit 1b.

[0029] The blood removal side circuit 1a is a flow path that introduces the blood removed from the patient P into the blood purifier 2. One end of the blood removal side circuit 1a is installed on the blood removal side puncture needle RN, and the other end is connected to the blood purifier 2. An on-off valve (solenoid valve) V1 is provided in the blood removal side circuit 1a. The flow of blood in the blood removal side circuit 1a is controlled by opening and closing the on-off valve V1. The blood return side circuit 1b is a flow path that returns the blood drawn out from the blood purifier 2 to the body. One end of the blood return side circuit 1b is installed on the blood return side puncture needle AN, and the other end is connected to the blood purifier 2. An on-off valve (solenoid valve) V2 is provided in the blood return side circuit 1b. The flow of blood in the blood return side circuit 1b is controlled by opening and closing the on-off valve V2.

[0030] The blood pump P1 is disposed in the blood removal circuit 1a and transports liquid within the blood circuit 1 in the direction from the blood removal circuit 1a to the blood return circuit 1b (hereinafter referred to as the forward liquid delivery direction) or in the direction from the blood return circuit 1b to the blood removal circuit 1a (hereinafter referred to as the reverse liquid delivery direction). The blood pump P1 is comprised of a peristaltic pump having a stator and a rotor, and is driven by the rotation of the rotor. The rotor is rotated by an actuator (not shown) such as an electric motor under the control of a control device C. The blood pump P1 is driven according to predefined operations during the blood return process, described later, but is also driven manually by the user (e.g., by pressing a manual button (not shown)).

[0031] When blood pump P1 rotates forward, it squeezes the blood removal circuit 1a, which is clamped between the stator and rotor, generating a forward flow. Conversely, when blood pump P1 rotates reversely, it squeezes the blood removal circuit 1a, generating a reverse flow. In blood pump P1, rotor speed is controlled and detected through closed-loop control using a pulse motor (not shown). Alternatively, instead of using a pulse motor for closed-loop control, a rotary encoder could be incorporated into blood pump P1 to detect the rotation of the rotary encoder and control the rotor's rotational speed.

[0032] The blood purifier 2 is also called a dialyzer and is used to purify the blood of the patient P. The blood purifier 2 includes a blood purification membrane (not shown in the figure) arranged inside. The blood purification membrane is formed by bundling hollow fibers (hollow fiber membranes) with holes in the side walls. The inside of the blood purification membrane is a blood flow path (not shown in the figure), and the outside of the blood purification membrane (hollow fiber) is a dialysate flow path (not shown in the figure). The blood flowing in the blood purifier 2 flows in the blood flow path, and unnecessary substances such as uremic toxins are removed by passing through the holes of the blood purification membrane through diffusion, ultrafiltration or both. The dialysate flowing in the blood purifier 2 passes through the dialysate flow path, and only the electrolytes contained in the dialysate and other substances required by the human body are replenished into the blood through the holes. In addition, the inside of the blood purification membrane can also be used as the dialysate flow path, and the outside of the blood purification membrane can be used as the blood flow path.

[0033] The dialysate inlet line IL is a flow path from the dialysate supply unit DS to the blood purifier 2, which supplies the dialysate from the dialysate supply unit DS to the blood purifier 2. The dialysate inlet line IL is mainly composed of a tube through which the dialysate can pass. An on-off valve (solenoid valve) V3 and a dialysate port P are provided on the dialysate inlet line IL. The flow of the dialysate to the blood purifier 2 is controlled by opening and closing the on-off valve V3. The dialysate port P takes out the dialysate. The blood circuit 1 and the dialysate inlet line IL are connected via the blood purification membrane of the blood purifier 2, so that the blood and the dialysate circulate with each other.

[0034] The drainage line EL is a flow path from the blood purifier 2 to the drainage section (not shown), discharging the dialysate from the blood purifier 2 to the drainage section. The drainage line EL is primarily composed of a tube through which the drainage can pass. The dewatering line RL is a flow path from the drainage line EL to the drainage section, removing water from the blood within the blood purifier 2. The dewatering line RL is primarily composed of a tube through which the drainage can pass.

[0035] The compound pump P2 is arranged across the dialysate inlet line IL and the drainage line EL. On the one hand, the compound pump P2 guides the dialysate to the downstream side of the dialysate inlet line IL in the direction of liquid delivery, and on the other hand, it discharges the dialysate discharge to the downstream side of the drainage line EL in the direction of liquid delivery. In other words, the compound pump P2 functions as a dialysate supply pump and a drainage pump. The dialysate supply pump is used to supply the dialysate to the blood circuit 1, and the drainage pump is used to discharge the dialysate from the drainage section. A plunger (not shown) is provided in the housing of the compound pump P2. The plunger divides the volume into the dialysate inlet line IL side and the volume on the drainage line EL side. The reciprocating motion of the plunger synchronizes the introduction of the dialysate and the discharge of the discharge.

[0036] Alternatively, a configuration may be employed in which, instead of the compound pump P2, a dialysate supply pump (not shown) is provided in the dialysate inlet line IL, and a drainage pump (not shown) is provided in the drainage line EL. In this case, the dialysate supply pump and drainage pump are configured as peristaltic pumps having a stator and a rotor, and are driven by the rotation of the rotor. The rotor is rotated by an actuator (not shown) such as an electric motor under the control of a control device C. The dialysate supply pump is driven (rotated) to squeeze the dialysate inlet line IL, which is clamped between the stator and rotor, generating a flow of dialysate. The drainage pump is similarly configured.

[0037] Dehydration pump P3 is installed in dehydration line RL. Dehydration pump P3 removes water from the blood within blood purifier 2 by draining the water from the blood through dehydration line RL. Since the amount of dialysate introduced into and discharged from blood purifier 2 is equal when compound pump P2 is driven, dehydration pump P3 removes water from the blood within blood purifier 2.

[0038] The priming liquid line PL connects the dialysate inlet line IL and the blood circuit 1. This line introduces the priming liquid (dialysate) into the blood circuit 1 and the blood purifier 2. Specifically, the priming liquid line PL runs from the dialysate port P to the blood-removal circuit 1a. An on-off valve (solenoid valve) V4 is installed in the priming liquid line PL. The opening and closing of the on-off valve V4 controls the flow of the priming liquid into the blood-removal circuit 1a.

[0039] Before dialysis treatment, a priming step is performed. During this step, the blood circuit 1 and blood purifier 2 are filled with priming fluid (displacing the air within the circuit with the priming fluid), thereby removing air from the circuit. During this step, the on-off valve V4 is opened and the on-off valve V3 is closed, allowing the priming fluid to flow through the priming fluid line PL and into the blood circuit 1 and blood purifier 2.

[0040] In this embodiment, the dialysate inlet line IL and the priming line PL are both used to introduce dialysate into the blood circuit 1 during the blood return process. Specifically, the dialysate inlet line IL and the priming line PL function as a dialysate inlet circuit for introducing dialysate into the blood circuit 1. Furthermore, the priming line PL is used to introduce air into the blood circuit 1 during the blood return process. Specifically, the priming line PL functions as an air inlet circuit for introducing air into the blood circuit 1. Furthermore, the drain line EL is used to transport drain fluid from the blood circuit 1 during the drain process after the blood return process. Details will be described later.

[0041] The bypass line BL1 and the bypass line BL2 are flow paths from the dialysate inlet line IL to the discharge line EL. An on-off valve (solenoid valve) V5 is provided on the bypass line BL1. Similarly, an on-off valve (solenoid valve) V6 is provided on the bypass line BL2. The opening and closing of the on-off valves V5 and V6 controls the flow of dialysate from the dialysate inlet line IL to the discharge line EL.

[0042] Bypass lines BL1 and BL2 are flow paths used to prevent inappropriate dialysate from flowing into the blood circuit 1. For example, a heater (not shown) is provided in the blood purification device 100 to heat the dialysate. During dialysis treatment, if the dialysate exceeds a specified temperature due to the heater, the dialysate is directed through bypass lines BL1 and BL2 to the drain line EL to prevent the high-temperature dialysate from flowing through the blood circuit 1. In this case, the on-off valves V5 and / or V6 are opened.

[0043] The air introduction unit 3 introduces air into the blood circuit 1 (blood removal circuit 1a) via the priming line PL. The air introduction unit 3 is connected to the priming line PL. The air introduction unit 3 pushes the dialysate introduced into the blood circuit 1 via the dialysate introduction line IL and the priming line PL into the return blood circuit 1b (or the blood removal circuit 1a), thereby returning the blood in the blood circuit 1 to the patient P. Details will be described later.

[0044] The air inlet portion 3 includes an air pump 3a, an air inlet passage 3b, an on-off valve (solenoid valve) 3c, an air filter 3d, and an air filter 3e. The air pump 3a has a rotor inside and is driven in a manner that the rotor rotates. The rotor is rotated by an actuator (not shown) such as an electric motor under the control of a control device C. In the air pump 3a, the speed of the rotor is controlled and detected by a closed-loop control using a pulse motor (not shown). In addition, a rotary encoder can be provided in the air pump 3a instead of the closed-loop control using a pulse motor, and the speed of the rotor can be controlled by detecting the rotation of the rotary encoder.

[0045] Air pump 3a is driven to introduce air into blood circuit 1 through air inlet path 3b and via priming line PL. An on-off valve 3c is provided between air inlet path 3b and priming line PL. Opening and closing on-off valve 3c controls the flow of air into priming line PL. Air filters 3d and 3e capture and remove bacteria and debris from the air.

[0046] Furthermore, in this embodiment, the air intake section 3 is connected to the priming line PL, but this configuration is not limiting. The air intake section 3 may also be connected to a fluid replacement line (not shown). The fluid replacement line, for example, is a flow path that introduces dialysate into the blood circuit to increase the amount of blood filtered from the patient during hemofiltration dialysis treatment or to replenish the blood. In this configuration, air from the air intake section 3 is introduced into the blood circuit 1 via the fluid replacement line.

[0047] The dialysate filters DF (dialysate filter DF1 and dialysate filter DF2) purify the dialysate by capturing substances such as endotoxins contained in the dialysate supplied from the dialysate supply unit DS. The dialysate filters DF are respectively arranged in the dialysate inlet line IL and include a primary chamber and a secondary chamber (not shown in the figure). In addition, the dialysate filter DF1 is provided with a dialysate purification membrane inside. The dialysate purification membrane is composed of a bundle of hollow fibers (hollow fiber membranes) having holes in the side walls. The dialysate filter DF is constructed in such a way that the dialysate flows from the primary chamber (the inside of the dialysate purification membrane) to the secondary chamber (the outside of the dialysate purification membrane). The dialysate filter DF has the characteristic of not allowing air to pass through the dialysate due to the surface tension of the water molecules while allowing water to pass through.

[0048] Electrode EPa (blood removal side) is provided in the blood removal circuit 1a. Electrode EPb (blood return side) is provided in the blood return circuit 1b. Electrodes EPa and EPb consist of conductors connected to flexible tubing, and electrode EPa is electrically connected to the power supply PS via a connection mechanism such as an alligator clip. Electrode EPb is also electrically connected to the needle removal detector 4. Electrodes EPa and EPb do not physically contact the blood but are electrically connected via the blood circuit 1.

[0049] Power supply PS applies a voltage to electrode EPa that generates a weak current (less than 1 mA) at a high frequency (several kHz to several tens of kHz). This voltage applied by power supply PS to electrode EPa causes current to flow through the blood removal puncture needle RN and the blood return puncture needle AN into the patient P's blood. Because the blood circulating extracorporeally through the blood removal circuit 1a and the blood return circuit 1b is a conductor for current flow, if the blood removal puncture needle RN and the blood return puncture needle AN are properly inserted into the patient P, current flows through the blood removal puncture needle RN and the blood return puncture needle AN into the patient P's blood.

[0050] The (body surface side) electrode EPc is attached closely to the body surface (skin) of the patient P. The electrode EPc is composed of an electrode attached closely to the puncture portion of the blood removal side puncture needle RN and the blood return side puncture needle AN at a position sandwiching the heart, and detects electrical signals from the body of the patient P. In addition, the electrode EPc is electrically connected to the needle removal detection unit 4 (at Figure 1 The electrode EPc is used to measure an electrocardiogram (biological information) from the patient P during dialysis treatment, for example.

[0051] The needle removal detector 4 detects that the blood loss-side puncture needle RN and / or the blood return-side puncture needle AN inserted into the patient P have been removed. The needle removal detector 4 is connected to the control device C. Figure 2 The relationship among the needle removal detection unit 4 , the electrode EPa, the electrode EPb, the electrode EPc, and the control device C is shown.

[0052] like Figure 2 As shown, electrodes EPa and EPb are connected to differential amplifier circuit A1, and electrode EPb is connected to impedance adjustment circuit IA. Furthermore, electrode EPc and impedance adjustment circuit IA are connected to differential amplifier circuit A2. Impedance adjustment circuit IA adjusts the impedance at the measurement voltage input to differential amplifier circuit A1 and the impedance at the measurement voltage input to differential amplifier circuit A2. Because there is a difference between the "blood impedance" obtained from electrodes EPa and EPb and the "body fluid impedance and skin impedance" obtained from electrodes EPb and EPc, impedance adjustment circuit IA adjusts this difference. Impedance adjustment circuit IA preferably adjusts the load resistance using a variable resistor or other means, or uses automatic gain control (AGC) to enable extraction of heartbeat components.

[0053] Differential amplifier circuit A1 generates an electric signal by amplifying the voltage difference between the measurement voltage from electrode EPa and the measurement voltage from electrode EPb. Differential amplifier A2 generates an electric signal by amplifying the voltage difference between the measurement voltage from electrode EPc and the measurement voltage from impedance adjustment circuit IA.

[0054] Furthermore, differential amplifier circuit A1 is connected to needle removal detector 4 via rectifier circuit R. Differential amplifier circuit A2 is connected to needle removal detector 4 via high-frequency cutoff filter HF. High-frequency cutoff filter HF removes high-frequency components applied by power supply PS from the electrical signal generated by differential amplifier circuit A2. The electrical signal generated by differential amplifier circuit A1 is input to needle removal detector 4, and the electrical signal generated by differential amplifier circuit A2 is input to needle removal detector 4.

[0055] The needle removal detection unit 4 detects changes in the patient P's internal impedance based on the electrical signal input from the differential amplifier circuit A2, thereby acquiring a predetermined biological parameter (an electrocardiogram in this embodiment). Specifically, in this embodiment, electrodes EPb and EPc form a pair to detect electrical signals from within the patient P's body. The needle removal detection unit 4 acquires the electrocardiogram (ECG), a biological parameter, in real time based on the detected electrical signals. Furthermore, the needle removal detection unit 4 monitors the current flowing through electrode EPb and, in real time, monitors changes in the patient P's internal impedance detected by the needle removal detection unit 4.

[0056] The control device C is a processing device that controls the structural elements of the blood purification device 100, such as controlling the drive of the blood pump P1. The control device C includes a computing device and a storage device (storage devices such as RAM and ROM). The computing device can also be implemented by a processor such as a CPU, a microcontroller, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), but its form is not limited.

[0057] Signals indicating changes in the current value and impedance monitored and detected by the needle removal detection unit 4 are transmitted to the control unit C. Based on the signals indicating changes in the current value and impedance, the control unit C determines whether the blood loss-side puncture needle RN and / or the blood return-side puncture needle AN have been removed from the patient P. If the blood loss-side puncture needle RN and / or the blood return-side puncture needle AN have been removed from the patient P, the current from the power supply PS does not reach the electrode EPb, and the needle removal detection unit 4 detects no current (the waveform corresponding to the current value is interrupted). Similarly, changes in impedance are not detected. In response to this state, the control unit C determines that the blood loss-side puncture needle RN and / or the blood return-side puncture needle AN have been removed from the patient P.

[0058] Furthermore, in this embodiment, the power supply PS applies a voltage to electrode EPa, and the needle removal detection unit 4 monitors the current flowing through electrode EPb. However, the voltage may be applied to either or both electrodes EPa and EPb. When the voltage is applied to electrode EPb, the power supply PS is connected to electrode EPb. Alternatively, the needle removal detection unit 4 may monitor the current flowing through either or both electrodes EPa and EPb. When monitoring the current flowing through electrode EPa, electrode EPa is connected to the needle removal detection unit 4.

[0059] The blood concentration detecting unit 5 (the blood concentration detecting unit 5a and the blood concentration detecting unit 5b) detects the concentration of the blood flowing in the blood circuit 1. The blood concentration detecting unit 5a is provided in the blood removal side circuit 1a, and the blood concentration detecting unit 5b is provided in the blood return side circuit 1b. The blood concentration detecting unit 5a and the blood concentration detecting unit 5b are implemented, for example, by an infrared emitter that emits infrared rays and an infrared sensor that detects the light. The amount of infrared rays that pass through the blood varies depending on the amount of red blood cells. Therefore, by detecting the amount of infrared rays that pass through the blood, the concentration of the blood flowing through the blood circuit 1 can be detected. The detected amount of infrared rays is sent to the control device C. The control device C determines whether the amount of light exceeds a predetermined threshold value.

[0060] The concentration of blood flowing in the blood circuit 1, as detected by the blood concentration detection unit 5, serves as a reference for determining the amount of blood returned during the blood return process. Details will be described later. In this embodiment, the blood concentration detection unit 5a and the blood concentration detection unit 5b are provided separately, but it is also possible to provide only one of the blood concentration detection unit 5a and the blood concentration detection unit 5b. When performing a blood return process in the forward direction of liquid delivery, the blood concentration detection unit 5b is preferably provided in the blood return-side circuit 1b. On the other hand, when performing a blood return process in the reverse direction of liquid delivery, which will be described later, the blood concentration detection unit 5a is preferably provided in the blood removal-side circuit 1a.

[0061] The bubble detectors 6 (bubble detectors 6a and 6b) detect bubbles generated in the blood and / or dialysate flowing through the blood circuit 1 during the blood return process. Bubble detector 6a is located in the blood removal circuit 1a, and bubble detector 6b is located in the blood return circuit 1b. Bubble detectors 6a and 6b are implemented, for example, by an ultrasonic emitter that emits ultrasonic waves and an ultrasonic sensor that detects the ultrasonic waves.

[0062] The ultrasonic sensor detects the voltage corresponding to the vibration of blood and / or dialysate. Bubbles have a higher attenuation rate than blood and / or dialysate. Therefore, the bubble detector 6 can detect the generation of bubbles by determining that the voltage value is below a predetermined threshold. The detected voltage value is transmitted to the control device C, which determines whether the voltage value exceeds the predetermined threshold.

[0063] The bubbles generated in the blood circuit 1, detected by the bubble detector 6, serve as a reference for terminating the blood return process midway. Details will be described later. In this embodiment, both the bubble detector 6a and the bubble detector 6b are provided, but only one of them may be provided. When performing a blood return process in the forward direction of liquid delivery, the bubble detector 6b is preferably provided in the blood return circuit 1b. On the other hand, when performing a blood return process in the reverse direction of liquid delivery (described later), the bubble detector 6a is preferably provided in the blood removal circuit 1a.

[0064] Next, refer to Figure 3 , explaining the relationship between the state mode and the driving state of the blood pump P1. In this embodiment, the blood pump P1 is in a non-working state after the blood return process is completed and before the needle removal is detected. If the needle removal is detected, it is in a working state. The non-working state means that the blood pump P1 is not driven even by manual operation of the user. That is, the blood pump P1 is not driven unless it is in a working state. The above two states are managed by the state machine implemented by the control device C as two state modes "working mode" and "non-working mode". The state mode is stored in a register (not shown).

[0065] The control device C refers to the state mode stored in the register and instructs the blood pump P1 to be driven only when the state mode is the operating mode. Thus, when the state mode is the operating mode, the blood pump P1 is driven according to predetermined operations during dialysis treatment and blood return procedures under the control of the control device C. Furthermore, when the state mode is the operating mode, the blood pump P1 is driven in response to manual operation by the user (e.g., by pressing a manual (drive) button (not shown)) and in accordance with the instructions of the control device C.

[0066] On the other hand, when the status mode is in the non-operating mode, the control device C does not issue an instruction to drive the blood pump P1 even when the drive button is pressed. In other words, when the status mode is in the non-operating mode, the blood pump P1 is locked so as not to be driven.

[0067] Figure 3 Indicates the transition of the state mode of the blood pump P1 and the action state of the predetermined action. The action state indicates whether the blood pump P1 is driven or stopped. Figure 3 In the example shown, the state mode switches between the operating mode and the non-operating mode by the actions performed at time points T1 to T6, and the blood pump P1 is in either the driving state or the stopping state. Figure 3 It is not shown in FIG. 1 , but before time T1 , a dialysis treatment is performed.

[0068] like Figure 3 As shown, the state mode of blood pump P1 is in the operating mode, which serves as the initial (default) state mode. When the blood return process is initiated at time T1 in this state mode, blood pump P1 is driven (rotated) according to the instruction of control device C (transitioning from the stopped state to the driven state). In the blood return process of this embodiment, dialysate is first introduced into the blood circuit 1 (dialysate introduction phase), and then air is introduced into the blood circuit 1 (air introduction phase).

[0069] Figure 4 The diagram shows the flow of the dialysate during the dialysate introduction phase in the blood return process. Figure 5 Indicates the flow of dialysate and air during the air introduction phase. Figure 4 and Figure 5 In the figure, when the on-off valve is open, the on-off valve shown in the figure is shaded, and when the on-off valve is closed, the on-off valve shown in the figure is blank. Figure 6 Subsequent figures are expressed in the same manner.

[0070] exist Figure 4 In the dialysate introduction phase shown, under the control of the control device C, the on-off valve V4 and the on-off valve V2 are opened. In addition, the blood pump P1 rotates forward. In addition, the compound pump P2 is driven. Thus, the dialysate from the dialysate supply unit passes through the dialysate introduction pipeline IL, the pre-filled liquid pipeline PL, the blood removal side circuit 1a, the blood purifier 2 and the blood return side circuit 1b. Figure 4 The thick dashed arrows in the figure indicate the flow of the dialysate. This flow of dialysate squeezes out the blood remaining in the blood purifier 2 and blood circuit 1 (return blood circuit 1b), returning the blood to the body. If a predetermined amount of dialysate flows through the blood circuit 1 in this state, the process switches to the air introduction phase.

[0071] If you switch to Figure 5 In the air introduction phase shown, the compound pump P2 stops driving under the control of the control device C. Instead, the air pump 3a is driven. Thus, air passes through the air introduction path 3b, the pre-filled liquid pipeline PL, the blood removal side circuit 1a, the blood purifier 2 and the blood return side circuit 1b. Figure 5 The air flow is indicated by a thick solid arrow in FIG. The air flow squeezes out the blood remaining in the blood purifier 2 and the blood circuit 1 via the dialysate introduced into the blood circuit 1 during the dialysate introduction phase, and returns the blood to the body.

[0072] In the blood return process described above, since air is introduced into the blood circuit 1 for blood return, the amount of dialysate used for blood return can be reduced compared to blood return using only dialysate. Furthermore, since air is introduced into the blood circuit 1 after the dialysate has been introduced, the air is forced out of the blood into the patient's body via the dialysate, thereby preventing air from being introduced into the patient's body.

[0073] Return to Figure 3 If Figure 4 or Figure 5 The blood return process is completed, that is, at time T2, the control device C determines that the blood return process has ended. Then, according to the instruction of the control device C, the state mode of the blood pump P1 is switched to the non-operating mode, and the blood pump P1 stops driving (switches from the driving state to the stopped state). The completion of the blood return process is determined based on, for example, whether a certain period of time has passed and / or whether the amount of blood returned has reached a predetermined threshold.

[0074] The control device C may also determine whether a predetermined period has elapsed based on the time measured by a timer from the start of the blood return process. The control device C may also determine whether the amount of blood returned has reached a predetermined threshold based on whether the rotational speed of the blood pump P1 exceeds a predetermined threshold (detecting the rotational speed of the blood pump P1 through the closed-loop control described above). Furthermore, the control device C may determine whether the amount of blood returned has reached a predetermined threshold based on whether the concentration of the blood flowing in the blood circuit 1 is below a predetermined threshold (detecting the concentration of the blood flowing in the blood circuit 1 through the blood concentration detector 5).

[0075] Furthermore, upon determining that the return bleeding process has concluded, the control device C instructs the power supply PS and the needle removal detection unit 4 to detect (monitor) the removal of the blood-removing puncture needle RN and / or the blood-returning puncture needle AN. At time T3, when needle removal monitoring begins, the power supply PS applies a voltage to electrode EPa, causing current to flow between electrodes EPa and EPb. The needle removal detection unit 4 detects this current through the patient P. If needle removal occurs, the needle removal detection unit 4 cannot detect current flow between the electrodes (or cannot detect a change in impedance from electrode EPc). Therefore, the needle removal detection unit 4 transmits an indicator indicating the absence of current flow to the control device C, which then determines that needle removal has occurred based on this indicator.

[0076] When the state mode of blood pump P1 is in non-operational mode, for example, even if the user presses the drive button, blood pump P1 does not drive. In such a state, before the withdrawal of the puncture needle is detected, the state mode is not switched to the operational mode, and blood pump P1 does not drive.

[0077] Then, if the removal of the puncture needle is detected, that is, if the control device C determines that the needle has been removed at time T4, the state mode of the blood pump P1 is switched to the operating mode by an instruction of the control device C. When the state mode is in the operating mode, for example, when the user presses the drive button, the blood pump P1 is driven.

[0078] If the blood return process is completed and the removal of the puncture needle is detected, the drainage process is performed to extract the dialysate remaining in the blood circuit 1. Figure 3 In the example shown, the drainage process is performed at time T5. The drainage process may be automatically initiated under the control of the control device C in response to the completion of the blood return process and the detection of needle removal, or may be initiated manually by the user.

[0079] Figure 6 Indicates the flow of the drainage fluid (dialysis fluid) in the drainage process. Figure 6 In the drainage process shown, the blood pump P1 is rotated forward to introduce air from the puncture needle RN, and the liquid remaining in the blood removal side circuit 1a is discharged to the drainage line EL. In this drainage process, the on-off valve V1 is opened under the control of the control device C. In addition, the blood pump P1 is rotated forward. As a result, the dialysate (drainage) remaining in the blood removal side circuit 1a and the blood purifier 2 passes through the blood removal side circuit 1a, the blood purifier 2 and the drainage line EL. Figure 6 In FIG, the flow of the dialysate is indicated by a thick dashed arrow.

[0080] In addition, there is also a case where a process (manual process) of disassembling the blood circuit 1 connected to the blood pump P1 is performed instead of the above-mentioned draining process. In this disassembling process, in order to disassemble the blood circuit 1, it is necessary to manually rotate the rotor of the blood pump P1. That is, during the disassembling process of the blood circuit 1, the blood pump P1 is still driven. Figure 6 The drainage step shown is merely an example, and for example, a blood return step of discharging the liquid remaining in the blood return circuit 1b to the drainage line EL may be performed.

[0081] According to this embodiment, in response to the completion of the blood return process, the puncture needle is detected for removal, and control is performed so that the blood pump P1 is not driven (operated) until needle removal is detected. This prevents the blood pump P1 from being driven when the drainage process or the blood circuit 1 disassembly process begins after the blood return process is completed without the needle being removed.

[0082] Next, refer to Figure 7 The flowchart shown describes the processing of the first embodiment. Figure 7 The processing shown corresponds to the process performed in Figure 3 The blood return process described in the figure is processed until the needle is removed. Although not shown in the figure, dialysis treatment is performed before the blood return process. Figure 3 The operation mode of the blood pump P1 described in is the operating mode (a status mode indicating the operating mode is stored in a register).

[0083] First, the control device C instructs the on-off valves (on-off valve V4 and on-off valve V2), blood pump P1, and compound pump P2 to perform the dialysate introduction step in the blood return process. In response to this instruction, the on-off valves are opened, blood pump P1 rotates forward, and compound pump P2 is driven (step S701). Figure 4 As described in , the dialysate from the dialysate supply unit is introduced into the blood circuit 1 .

[0084] Next, the control device C determines whether the dialysate introduction phase termination condition is satisfied (step S702). The process of step S702 is repeated until the dialysate introduction phase termination condition is satisfied.

[0085] Conditions for terminating the dialysate introduction phase may also include the passage of a certain period of time from the start of the dialysate introduction phase and / or the amount of returned blood reaching a predetermined threshold. As described above, whether the certain period of time has elapsed can also be determined by the control device C based on the time measured by a timer from the start of the dialysate introduction phase. The control device C can also determine whether the amount of returned blood has reached a predetermined threshold based on whether the number of revolutions of the blood pump P1 exceeds a predetermined threshold. Furthermore, the control device C can also determine whether the amount of returned blood has reached a predetermined threshold based on whether the concentration of the blood flowing in the blood circuit 1 is below a predetermined threshold (the concentration of the blood flowing in the blood circuit 1 is detected by the blood concentration detection unit 5).

[0086] If it is determined that the dialysate introduction phase termination condition is met, the control device C instructs the on-off valve (on-off valve 3c), compound pump P2, and air pump 3a to proceed with the air introduction phase in the blood return process. In response to this instruction, compound pump P2 stops driving. In addition, the on-off valve 3c opens, and the air pump 3a rotates (step S703). In this way, Figure 5 As described above, air is introduced from the air introduction portion 3 into the blood circuit 1 .

[0087] Next, the control device C determines whether the air introduction phase end condition (blood return process end condition) is satisfied (step S704). The process of step S704 is repeated until the blood return process end condition is satisfied.

[0088] Conditions for terminating the blood return process include: a certain period of time has elapsed since the start of the dialysate introduction phase (or air introduction phase) and / or the amount of blood returned has reached a predetermined threshold. Furthermore, conditions for terminating the blood return process may also include the situation where blood flowing in the blood circuit 1 is no longer detected and / or the situation where bubbles are detected in the blood circuit 1. The situation where blood flowing in the blood circuit 1 is no longer detected may also be determined by the control device C based on whether the concentration of the blood flowing in the blood circuit 1 is lower than a predetermined threshold (the blood concentration detection unit 5 detects the concentration of the blood flowing in the blood circuit 1). Furthermore, the situation where bubbles are detected in the blood circuit 1 may also be determined by the control device C based on whether a voltage corresponding to ultrasonic vibrations of the blood and / or dialysate flowing in the blood circuit 1 is lower than a predetermined threshold (the bubble detection unit 6 detects the voltage).

[0089] If the blood return process termination conditions are determined to be met, the control device C instructs the on-off valves (on-off valve 3c, on-off valve V4, and on-off valve V2), blood pump P1, and air pump 3a to terminate the blood return process. In response to this instruction, the on-off valves close, and blood pump P1 and air pump 3a stop operating (step S705).

[0090] Next, the control device C places the blood pump P1 in a non-operating state (step S706). Specifically, the operation mode of the blood pump P1 is shifted to the non-operating mode (the operation mode stored in the register is updated to the non-operating mode). Through the processing of step S706, the blood pump P1 is locked so as not to be driven.

[0091] Next, the control device C instructs the power supply PS and needle removal detector 4 to begin needle removal detection (monitoring) of the puncture needles (the blood loss-side puncture needle RN and the blood return-side puncture needle AN). In response to this instruction, the power supply PS applies voltage to the electrode EPa. Furthermore, the needle removal detector 4 detects current flowing through the patient P's blood and / or changes in the patient P's body impedance (step S707).

[0092] Then, the control device C determines whether needle removal is detected (step S708). The process of step S708 is repeated until needle removal is detected. The criteria for determining whether needle removal has been performed are as described above.

[0093] If needle removal is detected, blood pump P1 is placed in an operating state (step S709). Specifically, the operation mode of blood pump P1 is switched to operating mode (the operation mode stored in the register is updated to operating mode). Through the processing of step S709, blood pump P1 can be driven according to the instructions of control device C. The above-mentioned drainage process or disassembly process of blood pump P1 is then carried out.

[0094] According to the first embodiment, the blood pump P1 is inactive after the blood return process is completed and before needle removal is detected, thereby preventing the drainage process from being started while the puncture needle is still in place.

[0095] In this embodiment, after the blood return process is completed, the needle removal monitoring (ie, Figure 7 However, needle removal monitoring can be initiated at any time, not just after the blood return process has concluded. Needle removal monitoring can be initiated before the blood return process begins (e.g., during dialysis treatment) or at the time the blood return process begins. That is, needle removal monitoring can be initiated at any time, but at least at the conclusion of the blood return process.

[0096] In addition, in this embodiment, the blood return process is performed by introducing air into the blood circuit 1 after the dialysate is introduced into the blood circuit 1. However, the blood return process may be performed by introducing only the dialysate into the blood circuit 1 without introducing air into the blood circuit 1. In this case, the blood return process is performed by using Figure 4 The dialysate flow shown in the figure is used for the blood return process, and the Figure 7If the blood return process termination condition described in (Step S704) is met, the blood return process is terminated.

[0097] The configuration for monitoring and detecting needle removal described in this embodiment is merely exemplary, and the configuration using electrode EPc is not essential. At least one configuration is employed to detect the removal of the blood removal-side puncture needle RN and / or the blood return-side puncture needle AN based on the current flow between two electrodes provided in the blood removal-side circuit 1a and the blood return-side circuit 1b.

[0098] <Second embodiment>

[0099] Next, the second embodiment will be described. In the second embodiment, an example of performing a blood return process after dialysis treatment, a chronic blood purification therapy, will also be described. The second embodiment differs from the first embodiment only in the blood return process. In the blood return process of the second embodiment, the air inlet 3 directly introduces air into the blood circuit 1. Figure 8 This is a piping diagram showing the structure of the blood purification device 200 according to the second embodiment. The blood purification device 200 has the same structure as the blood purification device 100 according to the first embodiment, except that the structure of the air inlet portion 3 is different and that the blood removal side air capture chamber 7a and the blood return side air capture chamber 7b are included.

[0100] like Figure 8 As shown, the blood removal-side air capture chamber 7a is provided in the blood removal-side circuit 1a, and the blood return-side air capture chamber 7b is provided in the blood return-side circuit 1b. The main purpose of providing the blood removal-side air capture chamber 7a is to capture air generated by driving the blood pump P1 during dialysis treatment, etc., so that it does not flow into the blood purifier 2. The main purpose of providing the blood return-side air capture chamber 7b is to capture air so that it does not flow through the blood circuit 1 but into the patient's body. In other words, the blood removal-side air capture chamber 7a and the blood return-side air capture chamber 7b both function as chambers for receiving blood within the blood circuit 1.

[0101] The air inlet 3 (air inlet passage 3b) is connected to the blood removal-side air capture chamber 7a and the blood return-side air capture chamber 7b, introducing air into these chambers. Each of the blood removal-side air capture chamber 7a and the blood return-side air capture chamber 7b consists of two layers: a blood layer and an air layer. If air accumulates within these chambers, the liquid level drops, creating an airlock and potentially allowing air to enter the hollow fibers of the blood purifier 2.

[0102] exist Figure 8In the illustrated example, the air introduction unit 3 (air pump 3a) introduces air into the blood return-side air capture chamber 7b by forward rotation, thereby lowering the liquid level. Reverse rotation discharges air from the blood return-side air capture chamber 7b, thereby raising the liquid level. Similarly, the air introduction unit 3 (air pump 3a) introduces air into the blood removal-side air capture chamber 7a by forward rotation, thereby lowering the liquid level. Reverse rotation discharges air from the blood removal-side air capture chamber 7a, thereby raising the liquid level.

[0103] The air intake section 3 also includes an on-off valve (solenoid valve) 3f. The on-off valve 3f is positioned between the air intake passage 3b and the blood removal-side air capture chamber 7a. Opening and closing the on-off valve 3f controls the flow of air from the air intake section 3 to the blood removal-side air capture chamber 7a (the air intake section 3 directs air flow into the blood removal-side air capture chamber 7a). Opening and closing the on-off valve 3c controls the flow of air from the air intake section 3 to the blood return-side air capture chamber 7b (the air intake section 3 directs air flow into the blood return-side air capture chamber 7b).

[0104] During dialysis treatments and the like (i.e., outside the blood return process), the air introduction unit 3 functions as a liquid level adjustment pump for the air capture chamber 7a on the blood removal side and the air capture chamber 7b on the blood return side, as described above (a liquid level adjustment pump is not typically used for blood return). Meanwhile, during the blood return process, the air introduction unit 3 introduces air into the blood circuit 1 to return blood within the blood circuit 1 and the blood purifier 2 to the body.

[0105] In addition, the blood removal side air capture chamber 7a and the blood return side air capture chamber 7b are not necessarily structures. For example, in the case where the blood removal side air capture chamber 7a and the blood return side air capture chamber 7b are not provided, Figure 9 As shown, the air inlet 3 can also be connected to the blood return side circuit 1b, as shown in FIG. Figure 10 As shown, the air introduction section 3 may be connected to the blood removal side circuit 1a. In addition, it is not necessary to provide both the blood removal side air capture chamber 7a and the blood return side air capture chamber 7b, and only one of them may be provided.

[0106] Next, refer to Figures 11 to 13 , the blood return process of the second embodiment is described. In the blood return process of the second embodiment, Figure 8 In the described configuration, first, dialysate is introduced into the blood circuit 1 (dialysate introduction phase), and then, air is introduced into the blood circuit 1 (air introduction phase). Figure 11 Indicates the dialysate introduction phase. Figure 12 This shows the air introduction stage in which the air introduction section 3 introduces air into the blood return circuit 1b. Figure 13 This shows the air introduction stage where the air introduction section 3 introduces air into the blood removal circuit 1a. Figure 11The dialysate introduction phase shown is followed by Figure 12 and Figure 13 Either of the two air introduction stages is shown.

[0107] Figure 11 Indicates the flow of dialysate during the dialysate introduction phase. Figure 12 The flow of dialysate and air in the air introduction phase in which air is introduced into the blood return circuit 1b is shown. Figure 13 The flow of dialysate and air during the air introduction phase of the blood removal circuit 1a is shown. In the following figures, the on-off valve is shaded when it is open, and is blank when it is closed.

[0108] exist Figure 11 In the dialysate introduction phase shown, under the control of the control device C, the on-off valve V4 and the on-off valve V2 are opened. In addition, the blood pump P1 rotates forward. In addition, the compound pump P2 is driven. Thus, the dialysate from the dialysate supply unit passes through the dialysate introduction pipeline IL, the pre-filled liquid pipeline PL, the blood removal side circuit 1a, the blood purifier 2 and the blood return side circuit 1b. Figure 11 The thick dashed arrows in the figure indicate the flow of the dialysate. This flow of dialysate squeezes out the blood remaining in the blood purifier 2 and blood circuit 1 (return blood circuit 1b), returning the blood to the body. If a predetermined amount of dialysate flows through the blood circuit 1 in this state, the process switches to the air introduction phase.

[0109] If you switch to Figure 12 In the air introduction phase of introducing air into the blood return side circuit 1b, under the control of the control device C, the on-off valve V4 is closed, and the blood pump P1 and the compound pump P2 stop driving. Instead, the on-off valve 3c is opened. In addition, the air pump 3a is driven. As a result, air passes through the air introduction path 3b and the blood return side circuit 1b. Figure 12 The flow of air is indicated by a thick solid arrow in FIG. The flow of air squeezes out the blood remaining in the blood circuit 1 via the dialysate introduced into the blood circuit 1 during the dialysate introduction phase, and returns the blood to the body.

[0110] If you switch to Figure 13 In the air introduction phase of introducing air into the blood removal side circuit 1a, under the control of the control device C, the on-off valve V4 and the on-off valve 3c are closed, and the compound pump P2 stops driving. Instead, the on-off valve 3f is opened. In addition, the air pump 3a is driven. Thus, air passes through the air introduction path 3b, the blood removal side circuit 1a, the blood purifier 2, and the blood return side circuit 1b. Figure 13The air flow is indicated by a thick solid arrow in FIG. The air flow squeezes out the blood remaining in the blood purifier 2 and the blood circuit 1 via the dialysate introduced into the blood circuit 1 during the dialysate introduction phase, and returns the blood to the body.

[0111] exist Figure 13 In the illustrated configuration, the air inlet 3 is connected to the blood removal-side air capture chamber 7a and introduces air into the blood circuit 1. However, the blood pump P1 can also function as the air inlet 3. If, during the dialysate introduction phase, all of the dialysate introduced from the priming line PL has passed through the air pump P1 and the air pump P1 continues to rotate forward, air is introduced into the blood return-side circuit 1b. Therefore, in this case, the air inlet 3 may not be provided.

[0112] As described above, the air introduction unit 3 functions as a liquid level adjustment pump during dialysis treatment and also introduces air into the blood circuit 1 for blood return during the blood return process. The blood pump P1 transports the dialysate within the blood circuit 1 and also introduces air into the blood circuit 1 for blood return during the air introduction phase of the blood return process.

[0113] The dialysate introduction phase termination conditions and the blood return process termination conditions in the second embodiment are the same as those described in the first embodiment. The process of switching the state mode of the blood pump P1 is also the same as that described in the first embodiment.

[0114] The blood purification device 200 according to the second embodiment has been described above. In the second embodiment, it is also possible to prevent the situation where the drainage process is started without the puncture needle being removed, and the amount of dialysate used for blood return can be reduced compared to the case where only dialysate is used for blood return.

[0115] <Third embodiment>

[0116] Next, the third embodiment will be described. This embodiment primarily describes an example of an acute blood purification therapy, where apheresis is performed to remove the causative agent of an acute disease, followed by a blood return procedure. Furthermore, apheresis is merely an example of an acute blood purification therapy; this embodiment can also be applied to continuous renal replacement therapy (CRRT) and intermittent renal replacement therapy (IRRT).

[0117] Apheresis is a treatment method in which plasma exchange or the like is performed to separate and remove pathogenic substances from the blood. In apheresis, a double-lumen catheter is sometimes used as a temporary vascular access for blood purification. In the third embodiment, compared with the first embodiment, the structure of the needle removal detection unit is different as a puncture needle with a double-lumen structure is used. Therefore, in the third embodiment, only the structure of the needle removal detection unit and the puncture needle is described. The structure of the needle removal detection unit and the puncture needle shown in this embodiment can also be applied to an acute blood purification device used for acute blood purification therapies such as apheresis.

[0118] Figure 14 FIG is a diagram showing the structure of the needle removal detection unit 4 and the puncture needle N. Figure 14 As shown, the puncture needle N is inserted into the neck of the patient P. A needle removal detector 4 is attached to the puncture needle N, and the needle removal detector 4 is connected to a power source PS. The puncture needle N has a double-lumen structure (double-lumen catheter DLC).

[0119] The double-lumen catheter DLC mainly includes a puncture needle N, a double-lumen tube DLT, a blood removal side branch BA, and a blood return side branch BR. The double-lumen catheter DLC has a structure that branches from a puncture needle N to the blood removal side circuit 1a and the blood return side circuit 1b. One end of the double-lumen tube DLT is connected to the puncture needle N. The other end of the double-lumen tube DLT branches into the blood removal side branch BA and the blood return side branch BR. The blood removal side branch BA is connected to the blood removal side circuit 1a, and the blood return side branch BR is connected to the blood return side circuit 1b. In addition, Figure 14 The puncture site is shown as the neck, but the puncture site is not limited thereto and the thigh or subclavian area may also be punctured.

[0120] The puncture needle N is formed integrally with the wing portion W. The wing portion W is provided with a needle removal detection portion 4. The needle removal detection portion 4 is installed as a sheet-shaped touch sensor, for example, and is vapor-deposited on the wing portion W. That is, the needle removal detection portion 4 is integrated with the puncture needle N. The touch sensor can be a capacitive touch sensor or a resistive film touch sensor, etc. In the case where the needle removal detection portion 4 is installed as an electrostatic capacitance touch sensor, while the puncture needle N is puncturing the patient P, a power source PS is applied to the electrodes of the touch sensor to detect changes in electrostatic capacitance (charge) caused by the contact between the needle and the patient P. In the case where the needle removal detection portion 4 is installed as a resistive film touch sensor, while the puncture needle N is puncturing the patient P, a power source PS is applied to the electrodes of the touch sensor to detect changes in the resistance value of the transparent conductive film caused by the contact between the needle and the patient P.

[0121] In any of the above-described methods, the needle removal detection unit 4 can detect whether the puncture needle N has punctured the patient P by detecting changes in electrostatic capacitance or resistance of the transparent conductive film. Specifically, the needle removal detection unit 4 uses a touch sensor to detect the contact state of the puncture needle N with the patient's body surface, thereby detecting when the puncture needle N has been removed from the patient P. Furthermore, the needle removal detection unit 4 transmits the electrostatic capacitance or resistance value to the control device C, which determines that the needle has been removed based on the change in the capacitance or resistance value. This allows the needle removal detection unit 4 to detect needle removal even when the puncture needle inserted into the patient P is a single needle, such as a double-lumen catheter DLC.

[0122] The needle removal detector 4, as described above, detects the removal of the puncture needle N from the patient P. The conditions for terminating the dialysate introduction phase and the blood return process in the third embodiment are also the same as those described in the first embodiment. Furthermore, the process for switching the state mode of the blood pump P1 is also the same as that described in the first embodiment. Furthermore, the blood return process described in the second embodiment can also be applied to the third embodiment.

[0123] As described above, the blood purification device according to the third embodiment is described. In the third embodiment, it is possible to prevent the start of a drainage process, etc., while the puncture needle is not removed, and it is possible to detect the removal of the puncture needle even when a single-needle puncture needle such as a double-lumen catheter is used in acute blood purification therapy.

[0124] The embodiments described above are merely illustrative, and the scope of the embodiments is not limited to the examples described. In addition to the processes and components described, additional processes and / or components may be added. Furthermore, without departing from the scope of the present invention, the processes and / or components described may be modified, or specific processes and / or components may be omitted. Furthermore, the order of the processes described may also be changed.

[0125] In addition, the blood purification device of the embodiment is installed by a computer program executed by the control device C. However, the computer program may also be stored in a non-transitory storage medium. Examples of non-transitory storage media include read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as built-in hard disks and removable disk devices, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs).

[0126] Description of the label:

[0127] Reference numeral 1 represents a blood circuit;

[0128] Reference numeral 1a denotes a blood removal side circuit;

[0129] Reference numeral 1b indicates a blood return circuit;

[0130] Reference numeral 2 represents a blood purifier;

[0131] Reference numeral 3 denotes an air introduction portion;

[0132] Reference numeral 3a denotes an air pump;

[0133] Reference numeral 3b denotes an air introduction path;

[0134] Reference numeral 3c denotes an on-off valve;

[0135] Reference numeral 3d denotes an air filter;

[0136] Reference numeral 3e denotes an air filter;

[0137] Reference numeral 3f denotes an on-off valve;

[0138] Reference numeral 4 denotes a needle removal detection unit;

[0139] Reference numerals 5, 5a, and 5b denote blood concentration detection units;

[0140] Reference numerals 6, 6a, and 6b denote bubble detection units;

[0141] Reference numeral 7a denotes an air capture chamber on the blood removal side;

[0142] Reference numeral 7b denotes an air capture chamber on the blood return side;

[0143] Reference numeral 100 denotes a blood purification device;

[0144] Reference numeral 200 denotes a blood purification device;

[0145] Symbol IL represents the dialysate introduction line;

[0146] The symbol EL represents the discharge line;

[0147] The symbol PL represents the pre-fill liquid line;

[0148] Symbol P1 represents a blood pump;

[0149] Symbol P2 represents a dialysate pump;

[0150] Symbol P3 represents a liquid displacement pump;

[0151] Symbol P represents the dialysate port;

[0152] Symbols V1 to V6 represent on-off valves;

[0153] The symbol EPa represents the electrode;

[0154] The symbol EPb represents an electrode;

[0155] The symbol EPc represents electrode;

[0156] Symbol IA represents an impedance adjustment circuit;

[0157] Symbol A1 represents a differential amplifier circuit;

[0158] Symbol A2 represents a differential amplifier circuit;

[0159] The symbol R represents a rectifier circuit;

[0160] The symbol HF represents a high-frequency cutoff filter;

[0161] The symbol N represents a puncture needle;

[0162] The symbol W represents a wing;

[0163] The symbol RN indicates the puncture needle on the blood-removing side;

[0164] The symbol AN indicates the puncture needle on the blood return side;

[0165] The symbol DLC indicates a double-lumen catheter;

[0166] The symbol DLT indicates a double-lumen tube;

[0167] Symbol BA represents the blood-depleting side branch;

[0168] The symbol BR represents the blood return side branch;

[0169] Symbol C represents a control device;

[0170] Symbol PS represents a power supply.

Claims

1. A blood purification device, characterized in that: The blood purification device comprises: a blood circuit connected to a puncture needle inserted into a patient, wherein blood from the patient flows through the blood circuit; a blood pump, the blood pump being disposed in the blood circuit and being driven to transport the liquid in the blood circuit; a needle removal detection unit configured to detect whether the puncture needle has been removed from the patient; a control device that initiates a blood return process for returning blood in the blood circuit to the patient, and in response to determining that the blood return process has ended, sets the blood pump to a non-operating state; a dialysate introduction circuit for introducing dialysate into the blood circuit during the blood return step; and an air introduction part, which introduces air into the blood circuit during the blood return step to squeeze out the dialysate introduced into the blood circuit; The control device determines whether the dialysate introduction phase of introducing the dialysate into the blood circuit has been completed based on the amount of returned blood and / or the elapsed time, and in response to determining that the dialysate introduction phase has been completed, starts the air introduction phase of introducing the air into the blood circuit.

2. The blood purification device according to claim 1, characterized in that The control device sets the blood pump to an operating state in response to detecting the removal.

3. The blood purification device according to claim 1 or 2, characterized in that: The control device determines whether the blood return step has been completed based on the blood return amount and / or the elapsed time.

4. The blood purification device according to any one of claims 1 to 3, characterized in that: The control device determines that the blood return step has been completed based on the fact that no blood flowing in the blood circuit is detected and / or the fact that air bubbles are detected in the blood circuit.

5. The blood purification device according to claim 1, characterized in that The air introduction portion is connected to the dialysate introduction circuit, and introduces the air into the blood circuit through the dialysate introduction circuit.

6. The blood purification device according to claim 5, characterized in that: The dialysate introduction circuit includes a priming liquid pipeline. The priming liquid pipeline introduces the dialysate into the blood circuit in a priming step performed before the blood return process, and the blood circuit is filled with the dialysate.

7. The blood purification device according to claim 1, characterized in that: The air introduction portion is connected to the blood circuit and introduces the air into the blood circuit.

8. The blood purification device according to claim 7, characterized in that: The device further comprises a chamber, which is arranged in the blood circuit and receives the blood in the blood circuit. The air introduction portion is connected to the chamber, and adjusts the liquid level in the chamber by flowing air into the chamber except for the blood return step.

9. The blood purification device according to claim 7, characterized in that: The device further comprises a chamber, which is arranged in the blood circuit and receives the blood in the blood circuit. The blood pump is connected to the chamber and serves as the air introduction portion to introduce air into the chamber during the blood return step.

10. The blood purification device according to claim 1, characterized in that: The needle removal detection unit includes a touch sensor integrally formed with the puncture needle, and detects the contact state of the puncture needle with the patient's body surface via the touch sensor, thereby detecting that the puncture needle has been removed.

11. A blood purification device, comprising: a blood circuit connected to a puncture needle inserted into a patient, wherein blood from the patient flows through the blood circuit; a blood pump, the blood pump being disposed in the blood circuit and being driven to transport the liquid in the blood circuit; a needle removal detection unit configured to detect whether the puncture needle has been removed from the patient; It is characterized in that the above-mentioned blood purification device implements the following steps: a step of controlling the blood pump in order to perform a dialysate introduction phase of introducing dialysate into the blood circuit; a step of determining whether to terminate the dialysate introduction phase based on the amount of blood returned and / or the elapsed time; In response to determining that the dialysate introduction phase has ended, starting an air introduction phase of introducing air into the blood circuit; as well as After determining that the air introduction phase has ended, the blood pump is placed in a non-operating state until the puncture needle is detected to be pulled out.

Images