JP2009273749A - Hemodialysis system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hemodialysis system permitting setting of more detailed dialysis conditions. <P>SOLUTION: The hemodialysis system comprises an artery-side blood circuit, a vein-side blood circuit, a blood pump, a dialyzer, a dialysis solution feed circuit, a dialysis solution discharge circuit, and a dialysis solution control device for controlling the quantity of feeding and discharging of the dialysis solution. The hemodialysis system also comprises a waste solution flow measuring means for measuring the quantity of the waste dialysis solution discharged from the dialysis solution discharge circuit; a branched circuit disposed in the dialysis solution discharge circuit for feeding part of the discharged waste dialysis solution to the branched circuit; a substance concentration measuring means disposed in the branched circuit for continuously measuring the concentration of the substance in the waste dialysis solution flowing in the branched circuit; and a measuring result processing means for calculating the total quantity of the exchanged substance between the blood and the dialysis solution by the dialyzer during the dialysis treatment based on the result of measurement by the substance concentration measuring device and the waste solution flow measuring means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement in a hemodialysis system used for hemodialysis treatment that uses a dialyzer to exchange substances between dialysate and blood and remove excess water in the blood.

As kidney disease progresses and kidney function declines, the body's waste products and excess water cannot be excreted.
In order to improve such symptoms, the patient's blood is drawn out of the body, the drawn blood is guided to the dialyzer, and waste and excess water are removed from the blood with the dialyzer, and then returned to the patient's body. Dialysis treatment is performed.
A dialyzer used for hemodialysis treatment is provided with a plurality of hollow fibers therein, and is configured such that a dialysate flows outside the hollow fibers. The hollow fiber functions as a blood purification membrane with minute holes formed in its wall surface. With this configuration, when blood is passed through the hollow fiber, blood wastes and the like pass through the blood permeable membrane and are discharged into the dialysate, thereby purifying the blood. Further, by making the amount of dialysate discharged from the dialyzer using the pump larger than the amount of dialysate supplied to the dialyzer, excess water in the blood is drawn to the dialysate.

Dialysis conditions such as the type of dialyzer when starting hemodialysis treatment, the number of needles, blood flow, dialysis time, number of dialysis, and amount of water removal are usually determined based on blood test values to determine how much waste has accumulated. It is determined in consideration of weight gain and physique.
When hemodialysis treatment is actually started, blood tests are performed once or twice a month, and dialysis conditions are managed by comparing the test values of the blood tests. Specifically, if there is no significant change in the blood test results before and after dialysis, the dialysis conditions are maintained as they are.

JP-A-4-166166 JP 10-314299 A Japanese Patent Laid-Open No. 11-76395 JP 2006-102527 A JP 2006-346333 A

However, the amount of waste and excess water remaining in the body is not always constant and varies depending on the daily life of the patient during dialysis treatment. Therefore, depending on the patient's daily life (eating habits and fatigue level) during dialysis treatment, there may be days when blood flow, dialysis time, or water removal amount may be less than predetermined dialysis conditions. Some days are required. However, if dialysis conditions are managed by blood tests once or twice a month as in the past, setting dialysis conditions according to changes in physical condition due to such daily fine daily life Can not.
The greater the blood flow volume, dialysis time, and the number of dialysis times, the higher the blood purification efficiency.The blood purification efficiency increases even if the blood flow volume is increased using a large dialyzer, but the burden on the patient's body is also increased. Therefore, it is desirable to set dialysis conditions according to changes in physical condition of the patient's daily life if possible.
An object of the present invention is to provide a hemodialysis system that allows finer dialysis conditions to be set.

In order to achieve the above object, a hemodialysis system according to the present invention includes an arterial blood circuit provided with an arterial puncture needle, a venous blood circuit provided with a venous puncture needle, and the arterial blood circuit. A blood pump provided in a blood vessel, a dialyzer provided between an arterial blood circuit and a venous blood circuit, a dialysate supply circuit for supplying dialysate to the dialyzer, and a dialysate discharge circuit for discharging dialysate from the dialyzer And a hemodialysis system equipped with a dialysate control device for controlling the supply and discharge amount of dialysate, provided with a waste fluid flow rate measuring means for measuring the waste fluid amount discharged from the dialysate discharge circuit, A device in which a branch circuit is provided in the dialysate discharge circuit, a part of the discharged dialysate waste fluid is sent to the branch circuit, and the substance concentration in the dialysate waste fluid flowing through the branch circuit is continuously measured in the branch circuit. Measurement result processing for providing a concentration measurement means and calculating the total amount of exchanged substances exchanged between blood and dialysate by a dialyzer during dialysis treatment based on the measurement results of the substance concentration measurement device and the waste liquid flow rate measurement means Means is provided.
The substance in the dialysis waste liquid whose concentration is measured by the substance concentration measuring means may be urea, phosphate, sodium, potassium and / or creatinine.
When measuring the concentration of urea in the dialysis waste liquid by the substance concentration measuring means, by measuring the pH in the dialysis waste liquid that changes when the ammonia and carbon dioxide produced by the urease reaction of urea in the dialysis waste liquid are dissolved. The urea concentration can be measured continuously.
In this case, if necessary, the pH in the dialysis waste solution before the urea reaction of urea is also measured, and based on the measurement result, the pH of the dialysis waste solution after the urea urea reaction has occurred is measured. The measured value can be corrected.
In order to measure the pH in the dialysis waste liquid, the substance concentration measuring means includes a first pH electrode exposed in the branch circuit on which the urease-immobilized membrane is laminated, and at least upstream of the first pH electrode in the branch circuit. A second pH electrode may be provided.
Preferably, the measurement result processing means may be configured to calculate or estimate the concentration of the exchange substance in the blood of the patient based on the total amount of exchange substance calculated from the dialysis waste liquid. Then, based on the total amount of exchange material calculated from the dialysis waste liquid, an appropriate dialysis time can be set and / or an appropriate dialysis end point can be determined.
In addition, the hemodialysis system according to the present invention may include a storage unit that stores the processing result of the measurement result processing unit for each patient. In this case, the measurement result processing unit can be configured to determine the general state and / or the living state of the patient based on the past processing result stored in the storage unit and the current processing result.
Furthermore, the hemodialysis system according to the present invention comprises an output means, for example, a monitor, for comparing and displaying a past processing result stored in the storage means and a current processing result by the measurement result processing means. And a printer.

The hemodialysis system according to the present invention includes an arterial blood circuit provided with an arterial puncture needle, a venous blood circuit provided with a venous puncture needle, a blood pump provided in the arterial blood circuit, and an arterial side. A dialyzer provided between the blood circuit and the venous blood circuit, a dialysate supply circuit for supplying dialysate to the dialyzer, a dialysate discharge circuit for discharging dialysate from the dialyzer, and supply and discharge of dialysate In a hemodialysis system equipped with a dialysate control device for controlling the amount, a waste fluid flow rate measuring means for measuring the amount of waste fluid discharged from the dialysate drain circuit is provided, and a branch circuit is provided in the dialysate drain circuit A part of the discharged dialysis waste liquid is sent to a branch circuit, and the branch circuit is provided with substance concentration measuring means for continuously measuring the substance concentration in the dialysis waste liquid flowing in the branch circuit, Since there is a measurement result processing means that calculates the total amount of exchanged substances exchanged between blood and dialysate by the dialyzer during dialysis treatment based on the measurement results of the degree measurement device and the waste liquid flow rate measurement means, dialysis The total amount of exchange material exchanged between blood and dialysate can be known by the dialyzer during treatment. Knowing the total amount of exchanged material makes it possible to calculate and estimate the concentration of the exchanged substance in the patient's blood during dialysis treatment, so dialysis conditions must be evaluated each time dialysis treatment is performed. As a result, it is possible to set dialysis conditions according to changes in physical condition of the patient's daily life.
In particular, according to the hemodialysis system of the present invention, a branch circuit is provided in the dialysate discharge circuit, a part of the discharged dialysate waste liquid is sent to the branch circuit, and the dialysate waste liquid supplied to the branch circuit is used. Since the exchange substance concentration is measured, stable measurement results can be obtained without being affected by changes in the flow rate and flow rate of the dialysis waste liquid by controlling the supply and discharge rates of the dialysate during dialysis treatment. There is an effect.
Furthermore, by providing a substance concentration measuring means and a measurement result processing means separately from the dialysate control apparatus that controls the supply and discharge volumes of the dialysate, the supply and discharge volumes of the dialysate by the dialysate control apparatus can be reduced. It is also possible to monitor the control state and monitor the dialysis efficiency using a dialyzer. This produces the effect of promptly taking action when an abnormality occurs.
In the present invention, the removal amount of the waste product is calculated from the measurement of the substance concentration (that is, the waste solution component) in the dialysis waste solution, and the removal amount of the waste product from the blood is estimated. When hemodialysis treatment actually begins, blood tests are performed once or twice a month, and the amount of waste products removed from blood by dialysis treatment is confirmed. If the urea removal is not appropriate, there is also a problem that dialysis is insufficient. In other words, it cannot be said that dialysis is sufficiently performed just because the amount of urea in the blood is lowered by dialysis treatment. The urea concentration in the blood is not only dependent on the urea removal rate, but is also related to the urea production rate. This is because most of the nitrogen compounds of proteins in the blood are excreted as urea, so the urea production rate is related to the protein catabolism rate.
From the above, monitoring the urea concentration in the dialysate waste liquid, particularly continuous monitoring, can grasp the urea removal kinetics in dialysis treatment, and has the following effects.
(1) The dialysis treatment time can be optimized.
(2) The urea concentration in blood can be estimated.
(3) It can be used for dietary guidance for patients with malnutrition, extreme catabolism, or patients with high protein intake.
(4) Evaluation of cardiopulmonary recirculation when using artificial blood vessels, double lumen clavicular veins, internal jugular veins or femoral vein catheters.
(5) Evaluation of recirculation of blood access.
(6) Evaluation of dialyzer.
(7) Theoretical analysis (using the Compartment Model) is simple and accurate estimation is possible.
(8) A new safety management system during dialysis treatment that confirms the effect of appropriate treatment conditions can be constructed.
In addition, patients who have to undergo artificial dialysis have impaired or impaired kidney function. In the living body, phosphate is excreted through the kidney. If renal function is impaired, phosphate cannot be excreted, and the phosphate level in the blood rises. The phosphoric acid in the living body has a certain balance with the calcium ion concentration, and when the phosphoric acid concentration becomes high, calcium is supplied from bones and the like, and a function of lowering the phosphoric acid concentration occurs. When such a function occurs, various obstacles occur in the living body. Therefore, the management of the removal of phosphate is also important in hemodialysis.
In addition, many discussions have been made regarding fluctuations in water electrolyte during hemodialysis therapy. In particular, measuring Na ⁺ , K ⁺ , and Cl ^- ion concentrations in blood is important for diagnosis and treatment, and is regularly measured. Na ⁺ is the central cation in the extracellular fluid. Cl ^- together, mainly sodium chloride (NaCl), it is from the diet in the form of salt. K ⁺ is a major cation in the intracellular fluid that is taken orally as a meal and is released from cells in the body when catabolism is enhanced. In renal insufficiency, the central excretory route of the kidney is lost, so accumulation in the body becomes a problem. Na ⁺ accumulates in the body, resulting in hypertension and edema. The diet in dialysis patients is important Na ⁺ limit, in order to keep the body of Na ⁺ balance during dialysis, that is to remove the Na ^+, to lower the Na ⁺ value, the body and the dialysis fluid side concentration Removed with a gradient. Hyperkalemia is directly life-threatening due to impaired myocardial stimulation and can actively remove K ⁺ from the blood. However, when the serum K ⁺ level is rapidly decreased, hypokalemia occurs, and myocardial stimulation conduction disorder still occurs. The effect is particularly strong in patients with heart disease who are using diquitaris. Therefore, it is important to monitor closely the blood Na ⁺ and K ⁺ levels in dialysis patients with impaired kidney function and reflect them in treatment. In dialysis patients, regular measurement and control are important. In addition, grasping the amount removed by dialysis is an important point in appropriate dialysis treatment.

Embodiments of a hemodialysis system according to the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a schematic diagram showing the configuration of an embodiment of a hemodialysis system according to the present invention. As shown in the drawings, this hemodialysis system is configured by an arterial blood circuit 2 provided with an arterial puncture needle 1, a venous blood circuit 4 provided with a venous puncture needle 3, and a dialyzer 5. In this blood circuit, dialysis treatment is performed by purifying the patient's blood while circulating it extracorporeally.
A blood pump 6 is provided in the arterial blood circuit 2, and the blood flow sent to the blood circuit is adjusted by the blood pump 6.
A plurality of hollow fibers 5a are accommodated in the dialyzer 5 (in FIG. 1, only one hollow fiber is shown for explanation), and the hollow fibers 5a are minute on the wall surface. Pores are formed and function as a blood purification membrane. An arterial blood circuit 2 and a venous blood circuit 4 are connected to a passage 5b inside the hollow fiber 5a in the dialyzer 5, and a dialysate supply circuit 7 and a dialysate discharge circuit 8 are connected to a passage 5c outside the hollow fiber 5a. Is connected.
The dialysate supply circuit 7 is connected to a dialysate supply means (not shown) via a dialysate control device 9. The dialysate discharge circuit 8 is connected to a waste liquid tank (not shown) via a dialysate control device 9.
Inside the dialysate control device 9, there is provided a quantitative water removal control unit 9a extending over the dialysate supply circuit 7 and the dialysate discharge circuit 8, and the discharge amount of the water removal control unit 9a is controlled. Thus, the flow rate of the dialysate supplied to the dialyzer 5 is controlled.
Further, a water removal pump 9 b is provided inside the dialysate control device 9. The water removal pump 9b is provided in a bypass line 8a formed in the dialysate discharge circuit 8 so as to bypass the water removal control unit 9a. The water removal pump 9b is a pump for removing excess water from the blood of the patient flowing into the dialyzer 5, and when the water removal pump 9b is driven, the water removal control unit 9a is a quantitative type, so that the dialysate supply The amount of dialysis waste fluid discharged from the dialyzer 5 to the dialysate discharge circuit 8 is larger than the amount of dialysate introduced from the circuit 7 to the dialyzer 5, and the water is removed from the blood into the dialysate by the difference. The
With the configuration described above, the arterial puncture needle 1 is punctured into the patient's blood access, the venous puncture needle 3 is punctured into the patient's vein, and each pump is driven. Blood is guided to the inner passage 5b of 5a, and while the blood passes through the inner passage 5b of the hollow fiber 5a, blood waste and excess water permeate through the blood permeable membrane and are discharged into the dialysate, thereby purifying the blood. Is done. The blood that has passed through the inner passage 5b of the hollow fiber 5a in the dialyzer 5 enters the venous blood circuit 4, is defoamed in the drip chamber 10, and then returns to the patient's vein.
On the other hand, the dialysate led to the outer passage 5c of the hollow fiber 5a in the dialyzer 5 through the dialysate supply circuit 7 receives waste and excess water from the blood, and then passes through the dialysate discharge circuit 8 to waste liquid. Is done.

In the hemodialysis system configured as described above, a branch circuit 11 is formed in the dialysate discharge circuit 8.
The branch circuit 11 is provided with substance concentration measuring means 12.
As shown in FIG. 2, the substance concentration measuring means 12 includes a dialysis waste liquid passage 12b in the housing 12a.
Two detection parts 13 and 14 and a reference electrode 15 are provided in the housing 12a.
The first detection unit 13 on the upstream side (that is, the dialyzer side) includes a pH electrode, and detects the pH value of the dialysis waste liquid discharged from the dialyzer 5.
The second detection unit 14 on the downstream side is formed by laminating a urease layer 14b as an enzyme of urea on the pH electrode 14a. When the dialysis waste liquid passes through the second detection unit 14, urea extracted from the blood contained therein causes an enzyme reaction with the urease layer 14b. Thereby, ammonia and carbon dioxide are generated in the dialysis waste liquid, and the pH value of the dialysis waste liquid is changed. The second detection unit 14 detects the pH value changed by the enzyme reaction.
The reference electrode 15 is an electrode serving as a reference for the electrodes of the first detection unit 13 and the second detection unit 14, and the electrode outputs of the first detection unit 13 and the second detection unit 14 with respect to the electrode potential are measured result processing means 16. Sent to.
The pH values detected by the first and second detection units 13 and 14 of the substance concentration measurement unit 12 are output to the measurement result processing unit 16 via terminals connected to the detection units 13 and 14.

Based on the output signals from the detectors 13 and 14 of the substance concentration measuring means 12, the measurement result processing means 16 is a substance (specifically, a substance exchanged between blood and dialysate by the dialyzer 5 during dialysis treatment). In this embodiment, the total amount of urea extracted from the blood through the blood permeable membrane is calculated.
Specifically, the measurement result processing unit 16 obtains output signals from the first detection unit (pH sensor) 13 and the second detection unit (urea sensor) 14 of the substance concentration measurement unit 12.
Here, the output of the second detection unit (urea sensor) 14 changes along with the carbon dioxide and ammonia generated by the urease reaction in the urease layer 14b dissolved in water to become bicarbonate ions and ammonium ions. This is a signal from the pH electrode 14a.
The output of the first detection unit (pH sensor) 13 is a signal from the pH electrode of the pH of the dialysate waste liquid itself.
The measurement result processing means 16 obtains signals from both of the detectors 13 and 14, but the measurement result processing means 16 preliminarily monitors the urea concentration of the actual dialysate waste liquid before monitoring the urea concentration. Measure dialysate without water and dialysate with known concentrations of urea. That is, the measurement result processing means 16 measures in advance the relationship between the output of the first detection unit (pH sensor) 13 and the second detection unit (urea sensor) 14 and the urea concentration, and based on the relationship, Measure urea concentration in dialysate waste.
Regarding the outputs of the first detection unit (pH sensor) 13 and the second detection unit (urea sensor) 14, it is necessary to correct the fluctuation in pH in the dialysate waste liquid. Subtract the output of the second detection unit (urea sensor) 14 from the output of the detection unit (pH sensor) 13 and substitute the result obtained by subtracting into the calibration curve based on the urea concentration of a known concentration calculated in advance. Is calculated.
As shown in FIG. 1, the measurement result processing means 16 outputs not only the output from the substance concentration measuring means 12 but also the output from the waste liquid flow measuring means 17 disposed upstream of the branch circuit 11 in the dialysate discharge circuit 8. input.
The measurement result processing means 16 uses the urea concentration calculated based on the outputs of the first detection unit (pH sensor) 13 and the second detection unit (urea sensor) 14 based on the waste liquid flow rate input from the waste liquid flow rate measurement unit 17. Convert to urea amount.
The measurement result processing means 16 continuously calculates the urea amount in the dialysis waste liquid from the start to the end of a single dialysis treatment, integrates the calculation results, and discharges it to the dialysis fluid during the dialysis treatment. Calculate the total amount of urea produced.
The amount of exchanged substance calculated in the measurement result processing means 16 (the urea amount in this embodiment) is stored in the storage means 18 in association with the patient identification information.
The measurement result processing means 16 is configured to calculate or estimate the concentration of the exchange substance in the blood of the patient based on the total amount of exchange substance calculated from the dialysis waste liquid. The estimated concentration of the exchange substance in the blood of the patient is stored in the storage means 18 in association with the patient identification information.
Further, the measurement result processing means 16 includes the past processing results (total amount of exchange substances in dialysis waste liquid or blood) stored in the storage means 18 and the current processing results (total amount of exchange substances in dialysis waste liquid or blood). And the comparison result can be output via the output means 19 and, if necessary, the concentration of the past exchanged substance and the behavior to be removed are constant based on the past and the present processing result. Beyond the range, it can be determined that there is a change in the general condition and / or living condition of the patient and can be configured to determine it.
Various processing results obtained by the measurement result processing unit 16 and / or processing results stored in the storage unit 18 are output via an output unit 19 including a printer or a monitor as necessary.

FIG. 3 is a graph showing the result of continuous measurement of the urea concentration of the dialysis waste liquid during dialysis treatment by actually performing dialysis treatment for 3 hours on the patient using the hemodialysis system configured as described above.
From FIG. 3, it can be seen that the urea concentration in the dialysis waste liquid is temporarily lowered around 30 minutes (around 1800 seconds) after the start of dialysis treatment. According to the present invention, it is possible to accurately grasp the change in urea concentration that occurs during dialysis treatment in this way. For example, by collecting dialysis waste liquid and measuring the urea concentration at regular intervals. Then, there is a high possibility of overlooking a temporary change in urea concentration as shown in FIG.

In the embodiment described above, an example is described in which urea is detected as an exchange material by the substance concentration measuring means, but the exchange substance detected by the substance concentration measuring means is not limited to this embodiment, Any substance can be used as long as it is exchanged between blood and dialysate by dialysis treatment. For example, phosphate, sodium, potassium and / or creatinine can be detected.
In the above-described embodiment, the branch circuit 11 is provided on the downstream side of the dialysate control device 9 in the dialysate discharge circuit 8, but the position where the branch circuit 11 is provided is not limited to the present embodiment. You may provide in the upstream of the dialysate control apparatus 9 in the dialysate discharge circuit 8. FIG.
In the embodiment described above, the waste liquid flow rate measuring means 17 is arranged upstream of the branch circuit 11. However, the position where the waste liquid flow rate measuring means 17 is provided is not limited to this embodiment, and for example, downstream of the branch circuit 11. It may be arranged on the side. When the waste liquid flow rate measuring means 17 is arranged on the downstream side of the branch circuit 11, the waste liquid flow rate is measured by adding the amount of waste liquid flowing to the branch circuit 11. Further, the waste liquid flow rate measuring means 17 may directly measure the waste liquid amount, or may be configured to measure the flow rate of the waste liquid flowing through the dialysate discharge circuit 8 and calculate the waste liquid amount based on the flow rate. Good.
The configuration of the blood circuit composed of the arterial blood circuit, the venous blood circuit, the blood pump and the dialyzer, and the dialysate circuit comprising the dialysate supply circuit, the dialysate discharge circuit, the dialysate control device and the dialyzer is limited to this embodiment. Without being done, any existing hemodialysis circuit can be used.

1 is a schematic diagram showing a configuration of a hemodialysis system according to the present invention. (A) is a schematic diagram which shows the structure of a substance concentration measurement means and a measurement result processing means, (b) is a detection part and reference in a substance concentration measurement means for demonstrating schematic structure of the detection part in a substance concentration measurement means. It is a schematic sectional drawing of the part corresponding to an electrode. A graph showing the results of continuous measurement of the urea concentration of the dialysis waste liquid during dialysis treatment after dialysis treatment was actually performed on the patient for 3 hours using a hemodialysis system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arterial side puncture needle 2 Arterial side blood circuit 3 Vein side puncture needle 4 Vein side blood circuit 5 Dializer 5a Hollow fiber 5b Inner channel | path (blood channel)
5c Outer passage (dialysis fluid passage)
6 Blood Pump 7 Dialysate Supply Circuit 8 Dialysate Discharge Circuit 8a Bypass Line 9 Dialysate Control Device 9a Water Removal Control Unit 9b Water Removal Pump 10 Drip Chamber

DESCRIPTION OF SYMBOLS 11 Branch circuit 12 Substance density | concentration measurement means 12a Housing 12b Dialysis waste liquid channel | path 13 1st detection part 14 2nd detection part 14a pH electrode 14b Urease layer 15 Reference electrode 16 Measurement result processing means 17 Waste liquid flow rate measurement means 18 Memory | storage means 19 Output means

Claims (11)

An arterial blood circuit provided with an arterial puncture needle,
A venous blood circuit provided with a venous puncture needle,
A blood pump provided in the arterial blood circuit;
A dialyzer provided between the arterial blood circuit and the venous blood circuit;
Dialysate supply circuit for supplying dialysate to the dialyzer,
In a hemodialysis system comprising a dialysate discharge circuit for discharging dialysate from the dialyzer, and a dialysate control device for controlling the supply and discharge of dialysate,
Provided with a waste liquid flow rate measuring means for measuring the amount of waste liquid discharged from the dialysate discharge circuit,
A branch circuit is provided in the dialysate discharge circuit, a part of the discharged dialysate waste liquid is sent to the branch circuit, and a substance concentration measurement for continuously measuring the substance concentration in the dialysate waste fluid flowing through the branch circuit to the branch circuit. Providing means,
Based on the measurement results of the substance concentration measuring device and the waste liquid flow rate measuring means, a measurement result processing means for calculating the total amount of exchanged substances exchanged between blood and dialysate by the dialyzer during dialysis treatment is provided. Characterized hemodialysis system. The hemodialysis system according to claim 1, wherein the substance in the dialysis waste liquid whose concentration is measured by the substance concentration measuring means is urea. The hemodialysis system according to claim 1 or 2, wherein the substance in the dialysis waste liquid whose concentration is measured by the substance concentration measuring means is phosphoric acid, sodium, potassium and / or creatinine. The substance concentration measuring means continuously measures the urea concentration in the dialysis waste liquid by measuring the pH in the dialysis waste liquid that changes when the ammonia and carbon dioxide produced by the urease reaction of urea in the dialysis waste liquid are dissolved. The hemodialysis system according to claim 2. The substance concentration measuring means is
Measure the pH based on urease reaction of urea in the dialysis waste liquid, while measuring the pH in the dialysis waste liquid before urea urease reaction occurs,
Based on the measurement result of pH in the dialysis waste liquid before the urease reaction of urea occurs,
The hemodialysis system according to claim 4, wherein the measured value of pH in the dialysis waste liquid after the urease reaction of urea is corrected. The substance concentration measuring means is
A first pH electrode exposed in the branch circuit and laminated with a urease-immobilized membrane;
The hemodialysis system according to claim 5, further comprising: a second pH electrode disposed at least upstream of the first pH electrode in the branch circuit. The measurement result processing means is configured to calculate or estimate the concentration of the exchange substance in the blood of a patient based on the total amount of exchange substance calculated from the dialysis waste liquid. The hemodialysis system according to any one of 6. The hemodialysis system according to any one of claims 1 to 7, further comprising storage means for storing a processing result by the measurement result processing means for each patient. The measurement result processing means is configured to determine the general state and / or living state of the patient based on the past processing result stored in the storage means and the current processing result. The hemodialysis system according to claim 8. The hemodialysis system according to claim 1, wherein an appropriate dialysis time setting and / or an appropriate dialysis end point is determined based on a current processing result by the measurement result processing means. The output means which displays and / or prints by comparing the past process result memorize | stored in the said memory | storage means and the present process result by a measurement result process means is provided. The hemodialysis system described.

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