medical devices

Abstract

To accurately grasp a change of liquid flowing a pipeline by considering a change of light quantity of an external light.SOLUTION: In a medical device 1, a control part 60 acquires first value b showing a received light quantity of a light receiving part 30 in the state that light emission of a light emitting part 20 is stopped from the light receiving part 30 on the basis that a pipeline 10 is washed. The control part 60 further acquires from the light receiving part 30 second value c showing a received light quantity of the light receiving part 30 in the state that the light emission of the light emitting part 20 is stopped at predetermined timing after the first value b is acquired. The control part 60 calculates differential value (c-b) by subtracting from the second value c the first value b and sets value obtained by adding the differential value (c-b) to predetermined numerical value (p.a) as threshold y. The control part 60 outputs an alarm to an alarm part 50 when value showing the received light quantity of the light receiving part 30 in the state that light of the light emitting part 20 is emitted is below threshold y after the threshold y is set.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to medical devices. [Background technology]

[0002] JP 2018-531366 A (Patent Document 1) discloses a blood monitoring system as a medical device. The blood monitoring system measures blood characteristics and includes a controller, an emitter (e.g., LED) (light-emitting unit), and a sensor (light-receiving unit). The emitter emits light of multiple wavelengths, and the light enters the blood flow channel from a first side and exits the channel from a second side. The sensor is provided on the second side of the blood flow channel and detects characteristics of the light that are affected by blood components in the channel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2018-531366 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in Patent Document 1, there have been medical devices that include a light-receiving unit that receives light from a light-emitting unit via a flow path through which a liquid flows. In this case, the light-receiving unit may receive light other than the light emitted by the light-emitting unit (sometimes referred to as "external light") as well as light that is different from the light originating from the light-emitting unit. Furthermore, the amount of external light may change over time due to changes in the surrounding conditions of the medical device. Therefore, when accurately determining changes in the liquid flowing through a conduit in a medical device based on the amount of light received by the light-receiving unit, it is necessary to take into account the change in the amount of external light over time.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a medical device that can more accurately grasp changes in liquid flowing through a pipeline while taking into account changes in the amount of external light. [Means for solving the problem]

[0006] A medical device according to the present disclosure includes a light-emitting unit, a light-receiving unit, an alarm unit, and a control unit. The light-emitting unit emits light toward the pipeline. The pipeline is translucent and allows a liquid to flow through it. The light-receiving unit receives the light emitted by the light-emitting unit through the pipeline. The alarm unit issues an alarm. The control unit controls the operation of the light-emitting unit and the alarm unit. The control unit, based on the fact that the pipeline has been cleaned, acquires from the light-receiving unit a first value indicating the amount of light received by the light-receiving unit when the light-emitting unit has stopped emitting light. At a predetermined timing after acquiring the first value, the control unit further acquires from the light-receiving unit a second value indicating the amount of light received by the light-receiving unit when the light-emitting unit has stopped emitting light. The control unit subtracts the first value from the second value to calculate a difference value, and sets the value obtained by adding the difference value to a predetermined numerical value as a threshold value. After the threshold value is set, if a value indicating the amount of light received by the light receiving unit while the light emitting unit is emitting light falls below the threshold value, the control unit causes the alarm unit to output an alarm.

[0007] In the medical device according to one embodiment of the present disclosure, the control unit further acquires, based on the fact that the duct has been cleaned, a reference value indicating the amount of light received by the light receiving unit when the light emitting unit is emitting light from the light receiving unit, and sets the value calculated by multiplying the reference value by a predetermined coefficient less than 1 as the predetermined numerical value.

[0008] In a medical device according to an embodiment of the present disclosure, when a predetermined time has elapsed since the threshold value was set, the control unit again acquires from the light-receiving unit a second value indicating the amount of light received by the light-receiving unit with the light-emitting unit halted from emitting light, and the control unit calculates a difference value by subtracting the first value from the reacquired second value, and resets the value obtained by adding the difference value to a predetermined numerical value as the threshold value. [Effects of the Invention]

[0009] According to the present disclosure, a threshold is set using the difference between the first value and the second value corresponding to the change in the amount of external light, thereby making it possible to more accurately grasp changes in the liquid flowing through the pipeline while taking into account changes in the amount of external light. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a circuit diagram showing a circuit configuration of a medical device according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a partial enlarged view of a medical device according to an embodiment of the present disclosure. [Figure 3] 1 is a perspective view showing the appearance of a medical device according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a hardware configuration diagram of a medical device according to an embodiment of the present disclosure. [Figure 5] FIG. 10 is a flow diagram illustrating a process flow for preparing for alarm unit operation in a medical device according to an embodiment of the present disclosure. [Figure 6] FIG. 10 is a flow diagram illustrating a processing flow up to activating an alarm unit in a medical device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the configuration of a medical device according to an embodiment of the present disclosure will be described with reference to the drawings. In the following description of the embodiment, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and description thereof will not be repeated.

[0012] Fig. 1 is a circuit diagram showing the circuit configuration of a medical device according to an embodiment of the present disclosure. The medical device 1 according to an embodiment of the present disclosure shown in Fig. 1 is specifically a blood purification device, more specifically, a blood purification device used for continuous renal replacement therapy (CRRT). However, the blood purification device of the medical device 1 may also be a blood purification device used for any of continuous hemodiafiltration (CHDF), continuous hemofiltration (CHF), continuous hemodialysis (CHD), and slow continuous ultrafiltration (SCUF).

[0013] As shown in Fig. 1, the medical device 1 is configured so that a conduit 10 can be attached. The conduit 10 is a conduit that is translucent and through which a liquid flows. The conduit 10 is not particularly limited as long as it is a conduit that forms a circuit through which a liquid flows in the medical device 1 and is translucent, but the conduit 10 described in this specification is specifically a conduit through which a drainage liquid flows. The conduit 10 is, for example, a tube made of a soft resin, such as a tube whose base resin is polyvinyl chloride or polybutadiene.

[0014] The medical device 1 includes a plurality of pumps 11. Specifically, the plurality of pumps 11 includes a blood pump 11a, a dialysate pump 11b, a drainage pump 11c, a substitution fluid pump 11d, and a syringe pump 11e.

[0015] The medical device 1 further includes a blood purifier 12, and the blood pump 11a causes the patient's blood to flow into the blood purifier 12. There are no particular limitations on the type of blood pump 11a, but it is typically a rotary pump.

[0016] The dialysate pump 11b delivers dialysate to the blood purifier 12. The drainage pump 11c delivers drainage fluid discharged from the blood purifier 12. The substitution fluid pump 11d delivers a substitution fluid (replacement fluid) to the blood circuit of the medical device 1. The dialysate pump 11b, the drainage pump 11c, and the substitution fluid pump 11d are not particularly limited, but are typically peristaltic pumps. In this embodiment, the conduit 10 is attached to the drainage pump 11c. That is, when the medical device 1 is connected to a patient and operating as a blood purification device, the drainage fluid discharged from the blood purifier 12 flows through the conduit 10.

[0017] The syringe pump 11e is configured to be able to send a liquid medicine in a syringe to the blood circuit. The liquid medicine in the syringe may be, for example, an anticoagulant such as heparin or nafamostat.

[0018] The medical device 1 further includes one or more pressure gauges 13. Examples of the pressure gauges 13 include a pressure gauge that measures outlet pressure, a pressure gauge that measures inlet pressure, a pressure gauge that measures return pressure, and a pressure gauge that measures filtration pressure. The medical device 1 may further include other pressure gauges in addition to those described above.

[0019] Fig. 2 is a partially enlarged view of a medical device according to an embodiment of the present disclosure. As shown in Figs. 1 and 2, the medical device 1 further includes a light-emitting unit 20 and a light-receiving unit 30. Specifically, the light-emitting unit 20 is an infrared light-emitting diode (LED). The light-emitting unit 20 emits light toward the pipeline 10. The light-emitting direction from the light-emitting unit 20 toward the pipeline 10 intersects with the flow path direction of the pipeline 10. The light-emitting unit 20 is configured to be able to switch between emitting light and stopping light emission.

[0020] The light receiving unit 30 receives the light emitted by the light emitting unit 20 via the pipe 10. That is, the light emitting unit 20 is positioned so as to emit light toward the light receiving unit 30. The light receiving unit 30 is specifically an infrared sensor and includes, for example, a photodiode. The light receiving unit 30 receives external light, including the light emitted by the light emitting unit 20, and outputs a digital value indicating the amount of received light.

[0021] The medical device 1 further includes a conduit mounting portion 40. The conduit mounting portion 40 is configured to be able to mount a conduit 10. The conduit mounting portion 40 has a first support portion 41 and a second support portion 42 located spaced apart from the first support portion 41. The conduit 10 is sandwiched between the first support portion 41 and the second support portion 42, thereby allowing the conduit mounting portion 40 to hold the conduit 10. Furthermore, at least a portion of the light-emitting portion 20 is located within the first support portion 41. The light-emitting portion 20 is exposed from within the first support portion 41 towards the light-receiving portion 30. At least a portion of the light-receiving portion 30 is located within the second support portion 42. The light-receiving portion 30 is exposed from within the second support portion 42 towards the light-emitting portion 20.

[0022] FIG. 3 is a perspective view showing the appearance of a medical device according to one embodiment of the present disclosure. As shown in FIG. 3, the medical device 1 further includes an alarm unit 50. The alarm unit 50 issues an alarm. The alarm unit 50 notifies the operator of the medical device 1 of predetermined information by issuing an alarm. The alarm is specifically a flashing motion, but is not limited to this. The alarm may also be a sound. The alarm unit 50 is specifically an alarm lamp, but may also be an alarm light or alarm message information displayed on a screen.

[0023] Fig. 4 is a hardware configuration diagram of a medical device according to an embodiment of the present disclosure. As shown in Fig. 4, the medical device 1 further includes a control unit 60. The control unit 60 controls the operations of the pump 11, the light-emitting unit 20, and the alarm unit 50. The control unit 60 acquires the pressure value measured by the pressure gauge 13. The control unit 60 acquires a digital value indicating the amount of light received by the light-receiving unit 30 from the light-receiving unit 30.

[0024] The control unit 60 is specifically a control board, and includes a processor 61 and a memory 62. The control unit 60 controls the overall operation of the medical device 1. Specifically, the processor 61 controls the operation of the medical device 1 by executing various programs stored in the memory 62.

[0025] The medical device 1 has at least a priming mode for rinsing the circuit including the conduit 10 and a normal operation mode in which the medical device 1 is connected to a patient. In the priming mode, the conduit 10 may be filled with a cleaning fluid. Specifically, the cleaning fluid is physiological saline. In the normal operation mode, the conduit 10 is in a state in which a predetermined liquid corresponding to the position of the circuit installed within the medical device 1 flows through it, specifically, a drainage fluid discharged from the blood purifier 12 flows through it. The medical device 1 further includes an input unit 70 that can be input by an operator, and the control unit 60 switches between these modes based on an input signal acquired from the input unit 70. The input unit 70 is not particularly limited, but specifically, is a touch panel screen. The input unit 70 may be a keyboard, a mouse, or the like. The control unit 60 operates the pump 11, the light-emitting unit 20, and the alarm unit 50 according to each mode based on information acquired from the pressure gauge 13, the light-receiving unit 30, and the like.

[0026] Below, we will explain the processing that is performed to operate the alarm unit 50 based on a value indicating the amount of light received by the light receiving unit 30 when operating the medical device 1 according to one embodiment of the present disclosure in normal operation mode.

[0027] FIG. 5 is a flow diagram illustrating a process flow for preparing the alarm unit operation in a medical device according to an embodiment of the present disclosure. As shown in FIG. 5, first, the control unit 60 causes the light-emitting unit 20 to emit light based on the fact that the conduit 10 has been cleaned (step S11). Specifically, the control unit 60 causes the light-emitting unit 20 to emit light after all operations of the pump 11 in the cleaning mode have been completed and before the transition to the normal operation mode has been made. With the light-emitting unit 20 emitting light in step S11, the control unit 60 acquires a reference value a indicating the amount of light received by the light-receiving unit 30 from the light-receiving unit 30 (step S12). That is, the reference value a is a value indicating the amount of light received when the light emitted by the light-emitting unit 20 via the conduit 10 and ambient light (sometimes referred to as "external light") other than the light originating from the light-emitting unit are received in a state in which the cleaning-completed conduit 10 is filled with cleaning solution.

[0028] Then, the control unit 60 stops the light emission of the light-emitting unit 20 based on the fact that the pipe 10 has been cleaned (step S21). Specifically, the control unit 60 stops the light emission of the light-emitting unit 20 after all operations of the pump 11 in the cleaning mode have been completed and before the transition to the normal operation mode. Then, with the light emission of the light-emitting unit 20 stopped in step S21, the control unit 60 acquires a first value b indicating the amount of light received by the light-receiving unit 30 from the light-receiving unit 30 (step S22). In other words, the first value b is a value indicating the amount of light received when only external light is received in a state in which the pipe 10 after cleaning has been completed is filled with cleaning liquid.

[0029] In this embodiment, steps S21 and S22 are performed after steps S11 and S12, but may be performed before steps S11 and S12. Note that steps S11, S12, S21, and S22 are all performed in a state where the pipeline 10 is filled with cleaning liquid.

[0030] 6 is a flow diagram illustrating the flow of processing up to activating the alarm unit in a medical device according to an embodiment of the present disclosure. As shown in FIG. 6, the control unit 60 stops the light emission of the light-emitting unit 20 at a predetermined timing after acquiring the first value b (step S31). The timing of step S31 is a state in which the control unit 60 is at least operating the medical device 1 in the normal operation mode. At this timing, a predetermined liquid (in this embodiment, a drainage fluid) may or may not be flowing through the conduit 10.

[0031] Next, with the light-emitting unit 20 halted from emitting light in step S31, the control unit 60 further acquires a second value c indicating the amount of light received by the light-receiving unit 30 from the light-receiving unit 30 (step S32). That is, the second value c is a value indicating the amount of light received when only external light is received after a period of time has elapsed since the acquisition of the first value b. The second value c may also be a value indicating the amount of light received when only external light is received in a state in which a predetermined liquid (specifically, drainage fluid) is flowing through the conduit 10. The amount of external light received by the light-receiving unit 30 changes over time due to changes in the surrounding conditions of the medical device 1 and changes in the transparency of the liquid flowing through the conduit 10. For this reason, the second value c may have changed from the first value b acquired in step S22.

[0032] Next, the control unit 60 multiplies the reference value a acquired in step S12 by a predetermined coefficient p less than 1, and sets the calculated value as the provisional threshold. The coefficient p is arbitrarily set based on predetermined experiments, and in this embodiment, the coefficient p is set to, for example, approximately 0.925. The control unit 60 then subtracts the first value b from the second value c to calculate a difference value (cb), adds the difference value (cb) to the provisional threshold (p·a), and sets the resulting value as the threshold y (step S33). That is, the threshold y is set by correcting the provisional threshold (p·a) by the amount of the difference value (cb), which corresponds to a change over time in the amount of external light received by the light-receiving unit 30. For example, if the amount of external light received by the light-receiving unit 30 increases over time, the difference value (cb) becomes a positive value, and the threshold y is set higher than the provisional threshold (p·a). Furthermore, if the amount of external light received by the light receiving unit 30 decreases over time, the difference value (cb) becomes a negative value, and the threshold value y is set lower than the provisional threshold value (p·a).

[0033] After setting the threshold value y, the control unit 60 causes the light-emitting unit 20 to emit light (step S41). With the light-emitting unit 20 emitting light in step S41, the control unit 60 determines whether the value indicating the amount of light received by the light-receiving unit 30 is below the threshold value y (step S42). In this embodiment, in a situation where the transparency of the predetermined liquid flowing through the conduit 10 has decreased to a certain extent, the value of the provisional threshold value (p·a) is set in step S42 so that the amount of light received by the light-receiving unit 30 falls below the threshold value y. More specifically, when blood leakage from the blood purifier 12 occurs and the patient's blood is mixed into the effluent flowing through the conduit 10, causing the transparency of the effluent to decrease, the value of the provisional threshold value (p·a) is set so that the amount of light received by the light-receiving unit 30 falls below the threshold value y.

[0034] When the control unit 60 determines in step S41 that the acquired value indicating the amount of light received by the light receiving unit 30 is below the threshold y (YES in step S42) with the light emitting unit 20 emitting light, it causes the alarm unit 50 to output an alarm (step S51). In this embodiment, the operator of the medical device 1 can recognize the possibility of blood leakage based on the alarm.

[0035] If it is determined in step S41 that the value indicating the amount of light received by the light-receiving unit 30 is not below the threshold value y with the light-emitting unit 20 emitting light (NO in step S42), the control unit 60 determines whether or not a predetermined time has elapsed since the threshold value y was set (step S43). If the control unit 60 determines that the predetermined time has not elapsed since the threshold value y was set (NO in step S43), the control unit 60 returns to step S42 again and determines whether or not the value indicating the amount of light received by the light-receiving unit 30 is below the threshold value y with the light-emitting unit 20 emitting light. In this way, the control unit 60 does not change the threshold value y until the predetermined time has elapsed after setting the threshold value y, and continues to determine whether or not the value indicating the amount of light received by the light-receiving unit 30 is below the threshold value y.

[0036] If the control unit 60 determines that a predetermined time has elapsed since setting the threshold value y (YES in step S43), the process returns to step S31 and stops the light emission of the light-emitting unit 20. Then, with the light emission of the light-emitting unit 20 stopped in step S31, the control unit 60 again acquires a second value c' indicating the amount of light received by the light-receiving unit 30 from the light-receiving unit 30 (step S32). The control unit 60 subtracts the first value b from the reacquired second value c' to calculate a difference value (c' - b), and adds the difference value (c' - b) to a predetermined value to reset the threshold value y' (step S33). Thus, the threshold value y' is reset by correcting the provisional threshold value (p·a) by the difference value (c' - b), which corresponds to further changes over time in the amount of external light received by the light-receiving unit 30. In this way, the threshold value y' is periodically reset in the normal operation mode.

[0037] As described above, in the medical device 1 according to this embodiment, the control unit 60 acquires, based on the fact that the conduit 10 has been cleaned, a first value b indicating the amount of light received by the light-receiving unit 30 when the light-emitting unit 20 has stopped emitting light from the light-receiving unit 30. At a predetermined timing after acquiring the first value b, the control unit 60 further acquires, from the light-receiving unit 30, a second value c indicating the amount of light received by the light-receiving unit 30 when the light-emitting unit 20 has stopped emitting light. The control unit 60 subtracts the first value b from the second value c to calculate a difference value (cb), and adds the difference value (cb) to a predetermined value (p·a) to set the resulting value as the threshold value y. After the threshold value y is set, the control unit 60 causes the alarm unit 50 to output an alarm when the value indicating the amount of light received by the light-receiving unit 30 when the light-emitting unit 20 is emitting light falls below the threshold value y.

[0038] According to the above configuration, the threshold value y is set using the difference between the second value c corresponding to the change in the amount of external light and the first value b, so that it is possible to more accurately grasp the change in the amount of external light and the change in the liquid flowing through the pipeline 10. As a result, it is possible to prevent the alarm unit 50 from operating unintentionally.

[0039] In the medical device 1 according to this embodiment, the control unit 60 further acquires, based on the fact that the pipeline 10 has been cleaned, a reference value a indicating the amount of light received by the light receiving unit 30 when the light emitting unit 20 is emitting light, from the light receiving unit 30. The control unit 60 sets the value calculated by multiplying the reference value a by a predetermined coefficient p that is less than 1 as the predetermined numerical value (p·a).

[0040] According to the above configuration, the numerical value serving as the reference for threshold value y is set when the pipeline 10 is attached to the medical device 1, so that changes in the liquid within the pipeline 10 can be grasped more accurately regardless of the type of pipeline 10.

[0041] In the medical device 1 according to this embodiment, when a predetermined time has elapsed after setting the threshold value y, the control unit 60 again acquires from the light-receiving unit 30 a second value c' indicating the amount of light received by the light-receiving unit 30 when the light-emitting unit 20 has stopped emitting light. The control unit 60 subtracts the first value b from the reacquired second value c' to calculate a difference value (c'-b), and then adds the difference value (c'-b) to a predetermined numerical value (p·a) to reset the value obtained as the threshold value y'.

[0042] According to the above configuration, even if the amount of external light further changes over time while the medical device 1 is in operation, the change can be reflected again in the threshold value y'. This makes it possible to more accurately grasp changes in the liquid flowing through the conduit 10 while taking into account further changes in the amount of external light. As a result, unintended operation of the alarm unit 50 can be suppressed.

[0043] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0044] 1 medical device, 10 pipe, 11 pump, 11a blood pump, 11b dialysis fluid pump, 11c drainage pump, 11d replacement fluid pump, 11e syringe pump, 12 blood purifier, 13 pressure gauge, 20 light emitting unit, 30 light receiving unit, 40 pipe attachment unit, 41 first support unit, 42 second support unit, 50 alarm unit, 60 control unit, 61 processor, 62 memory, 70 input unit.

Claims

1. a light-emitting portion that is translucent and emits light toward a pipe through which the liquid flows; a light receiving unit that receives the light emitted by the light emitting unit through the pipe; an alarm unit that issues an alarm; a control unit that controls operations of the light emitting unit and the alarm unit, The control unit acquiring, from the light-receiving unit, a first value indicating an amount of light received by the light-receiving unit in a state in which light emission by the light-emitting unit is stopped based on the completion of cleaning of the pipeline; At a predetermined timing after acquiring the first value, a second value indicating the amount of light received by the light receiving unit is acquired from the light receiving unit in a state in which light emission by the light emitting unit is stopped; subtracting the first value from the second value to calculate a difference value, and adding the difference value to a predetermined value to set the obtained value as a threshold value; After the threshold value is set, if a value indicating the amount of light received by the light receiving unit while the light emitting unit is emitting light falls below the threshold value, the medical device causes the alarm unit to output an alarm.

2. The control unit Based on the completion of cleaning of the pipeline, a reference value indicating the amount of light received by the light receiving unit in a state in which the light emitting unit is emitting light is further acquired from the light receiving unit; The medical device according to claim 1 , wherein a value calculated by multiplying the reference value by a predetermined coefficient less than 1 is set as the predetermined numerical value.

3. The control unit When a predetermined time has elapsed after setting the threshold value, a second value indicating the amount of light received by the light receiving unit is acquired again from the light receiving unit in a state where light emission by the light emitting unit is stopped; 3. The medical device according to claim 1, wherein the threshold value is reset by subtracting the first value from the reacquired second value to calculate a difference value, and adding the difference value to the predetermined numerical value.

Images