JP2001506873A - System and method for non-invasive measurement of hemodynamics in a hemodialysis shunt - Google Patents

Abstract

Abstract: Access recirculation in a shunt is determined quantitatively by injecting a standard solution, such as saline, into the patient's (200) blood stream upstream of the shunt. At a certain point on the access path, the time change of the hematocrit value (delta H) is measured by photometry. The electronics (150) receives the signal from the detector (100), compares the integrated area of Delta H with the time of the initial standard solution through the access of the recirculating solution, and indicates recirculation (152).

Description

DETAILED DESCRIPTION OF THE INVENTION Cross-Reference to Systems and Methods for Non-Invasive Measurement of Hemodynamics in Hemodialysis Shunts This application is filed in US Provisional Patent Application No. 60/029587, filed October 23, 1996. Prioritize. FIELD OF THE INVENTION The present invention relates to systems and methods for non-invasive measurement of hemodynamics at hemodialysis access sites and for access recirculation and blood flow. More specifically, the present invention provides a spectrometer for quantitatively measuring shunt (access site) recirculation, blood flow at the access site, blood flow of the dialysis machine, and the amount of nominal fluid required in the piping for hemodialysis. The present invention relates to a photometric measurement system and method. Introduction In modern medicine, many methods and indicators are used to determine the condition of patients undergoing dialysis treatment in particular. Hemodialysis is a procedure used when it is necessary to use an artificial kidney in place of a patient's kidney to remove certain biological waste. If the human kidney fails to function properly to remove waste products such as urea, potassium, and excess water, blood is removed from the patient through a blood line and filtered through an artificial kidney or dialyzer. It becomes necessary. In this procedure, the blood is purified through a dialyzer before being returned to the patient's normal circulation system. Access to the patient's circulatory system is provided using a surgically implanted shunt or fistula. The "access site" is typically the arm, foot, or neck of the patient. Usually, a plurality of needles are arranged at the "access site", and the blood on the "arterial side", that is, the upstream side of the dialyzer is removed, and the purified blood is placed downstream, that is, "the venous side" of the position of the first needle. Make it easy to return. Unfortunately, however, over time, the fistula or shunt often becomes plugged or "stenotic." As a result, blood flow through the access site is reduced, ultimately requiring shunt angioplasty or surgical replacement. If the shunt fails "fully clogged", a portion of the dialysis-purified blood will flow back to the arterial removal site, recirculate and dialyze again. This is called "access recirculation". As such recirculation of the purified blood continues, the remaining portion of the patient's circulating blood will not be properly purified, and the patient will receive an inappropriate dialysis volume. To avoid the danger of inadequate dialysis volume caused by such direct recirculation of purified blood returning to the withdrawal site, 1) the degree or percentage of access recirculation, 2) the actual situation within the shunt itself Various techniques and methods have already been devised for determining the blood flow rate of the dialyzer, and 3) the blood flow rate of the dialyzer itself. Medical professionals are reluctant to know these three parameters quantitatively, not just qualitatively, to determine the presence and degree of clogging or stenosis. These parameters are necessary to predict when access will be compromised and to determine the need to surgically repair access. The blood flow Q measured by the so-called Ficke dilution method is described in AC Guyton, "A textbook of medical physiology (A.C. Guyton, Textbook of Medical Physiology), 6th edition, page 287, 1981". Where Q is equal to the infused diluent divided by the average concentration of the diluent times the transit time of the diluent through the blood vessels. The dilution curve can be obtained by continuous monitoring, or the time course of the concentration of the diluent (ie, the medium) may be measured. L., American Journal of Kidney, 20: 6, 1992, pp. 598-602, show that reversing the blood flow path of a dialyzer increases blood recirculation. tski) shows in European Patent Application WO 96608305 A1 that the actual blood flow in the shunt can be determined by reversing the blood flow path (which forces recirculation). Some measurement methods use a color-coded dual sonographic method, but this method is expensive.This method requires skilled specialists and the measurement is less sensitive to operator error. In addition, this method is complicated by the limitations of the different vessel diameters and the angle of Doppler flow, and the intravenous infusion of saline solution. There is also a method of optically detecting a change in the intensity of light passing through a conduit at one upstream point and recording the change (U.S. Pat. No. 5,321,550). There is also a method of injecting a bolus of saline into the dialyzer line and measuring the change in the speed of the ultrasound (U.S. Pat. No. 5,453,576), which measures the temperature, Sensitive to changes in plasma protein levels, and other intrinsic factors, but more importantly in this case, the absolute velocity of the ultrasound is not only dependent on the intrinsic factors of the blood, but also of the unknown of the pipeline itself. In order to compensate for these intrinsic and extrinsic physical problems, it is common to add salt in opposing plumbing, either arterial or venous. It is necessary to perform a calibrated injection, thereby creating a relative change in dilution with a bolus of saline. In this way, the effects of unknown ultrasonic characteristics and other physical and dimensional characteristics of the pipeline can be minimized. This standard access recirculation assay requires three blood urea nitrogen samples from a patient on dialysis. However, in order for urea nitrogen measurements to be correct, in addition to taking blood samples from the patient, it is necessary to maintain patient care, experimental costs, and adequate blood flow during the actual sampling process. Required. Thus, there remains a need for systems and methods for non-invasively and quantitatively determining hemodynamic and blood recirculation parameters of blood flow at a patient's access site. OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide an access non-invasive hemodynamic monitoring system and method that minimizes nursing time and does not require direct blood sample collection. It is another object of the present invention to provide a system and method for displaying immediate and continuous visual information on hemodynamic data of access by saline dilution. Yet another object of the present invention is to provide access to blood flow under a variety of conditions including different ultrafiltration volumes, patient positions, tubing types and dimensions, and even different dialyzer membranes and dialysis delivery systems. To provide a repeatable and reliable system and method for non-invasive determination of hemodynamics of a patient. Another object of the present invention is to provide means and a method for quantitatively determining the flow rate Q of blood actually passing through a dialyzer. Another object of the present invention is to present a dilution concentration-time curve to an operator on a visual real-time display means. It is yet another object of the present invention to provide a system and method that allows an immediate determination of the amount of priming fluid actually required for a dialyzer circuit. It is another object of the present invention to provide a system and method for determining access blood flow and access recirculation that does not require infusion of saline. This is done, for example, by changing the ultrafiltration (UFR) or the blood flow of the dialyzer. It is another object of the present invention to provide a system and method for measuring blood flow parameters of a dialyzer. These and other objects and advantages of the present invention will become more apparent from the following description and appended claims, and will be understood by the practice of the invention. SUMMARY OF THE INVENTION In one aspect of the invention, access recirculation of a shunt is determined quantitatively by injecting a standard solution, such as a saline solution, into a patient's blood stream at one upstream point of the shunt. Is done. At a certain point in the access path, the luminous intensity of the change over time (ΔH) of the hematocrit value is measured. An electronic circuit receives the signal from the detector and provides an almost instantaneous indication of the amount of access recirculation as compared to the integrated area of the aging ΔH of the initial standard and recirculating solutions flowing through the access. In another aspect of the invention, access recirculation and / or access blood flow is determined quantitatively without injecting a solution into the blood stream. In this aspect, the degree of access recirculation and / or access blood flow is determined by the method of altering the blood flow or ultrafiltration (UFR) of the dialyzer to determine a corresponding change in the concentration of one component of the blood. It is determined quantitatively. In this method, the concentration of one component of the blood is measured as a function of the blood flow or UFR of the dialyzer, and electronics converts these measurements to quantitatively determine access recirculation and / or access blood flow. Judge and display it almost immediately. One preferred embodiment of the component of blood to be measured includes red blood cells. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a typical dialysis tubing connection circuit. FIG. 2 is a graph plotting the% change in hematocrit over time (or% change in blood volume (BV) over time) after injecting 10 ml of saline solution into the bloodstream at an upstream location of the shunt. It is. FIG. 3 is a graph showing a single injection dilution curve when access recirculation is present. Note the second area (curve 2) after the relatively large first area (curve 1). FIG. 4 is a graph showing a single infusion dilution curve when the arterial and venous lines are reversed to force (reversed) recirculation. FIG. 5 is a diagram showing a dialysis circuit relating to mass flow in a normal duct direction of the arterial system and the venous system. FIG. 6 is a diagram showing a dialysis circuit relating to mass flow when the directions of the arterial and venous conduits are reversed. DETAILED DESCRIPTION OF THE INVENTION In one preferred embodiment, measurements are made using the devices described in U.S. Patent Nos. 5,456,253 and 5,372,136. These patent documents are attached in their entirety to the present application. All of these patents form part of the disclosure of the present invention. That is, in one preferred embodiment, the hematocrit is measured on the blood flowing through a cuvette located in the access line. In one preferred embodiment, the device and signal manipulation described in US Pat. No. 5,372,136 is used to measure hematocrit. The numbered components are the same as those in FIG. 1 of US Pat. No. 5,456,253. In hemodialysis, blood is removed from the patient 200 by means of a collection catheter. FIG. 1 shows an example of the input catheter 122. An input catheter 122 is inserted into the vein of patient 200 at site 180 and is used to define a blood passage upstream of a blood filter used to filter blood to remove impurities. The blood filter is also called a dialyzer 130. Dirty blood flows from the artery in the patient 200 to a pump means, for example, a pump 140. Blood further flows from pump 140 to dialyzer 130. The dialyzer 130 has an inlet 230 and an outlet 240. Pump 140 serves to move the contaminated blood from patient 200 into inlet 230 and through dialyzer 130 out of dialyzer 130 at outlet 240. Specifically, dirty blood in input catheter 122 is sent to inlet 230 of dialyzer 130. After being cleaned through the dialyzer 130, the blood may undergo other treatments, such as heparin infusion, within components 300 related to hemodialysis. The cleaned blood after the dialysis treatment is returned to the patient 200 by output catheter means, for example, output catheter 124. Output catheter 124 is also inserted into the vein of patient 200 at site 180 and serves to define a blood passage downstream from dialyzer 130 and return blood exiting dialyzer 130 to patient 200. As mentioned above, hemodialysis uses a blood filter or dialyzer 130 to purify the blood of the patient 200. As the blood passes through the dialyzer 130, it travels in a straw-like tube (not shown) in the dialyzer 130 that serves as a membrane path for dirty blood. This straw-like tube removes toxics and excess fluid by diffusion. Examples of excess fluid in soiled blood include water, and examples of toxics in soiled blood include blood urea nitrogen (BUN) and potassium. In ultrafiltration, excess fluid and toxics are removed by a clean dialysate, which is a solution of drug and water. Clean dialysate enters the dialyzer 130 at the input line 210 from the controller and tank combination 170. As the dialysate flows through the dialyzer 130, it flows around the straw-like tubing. The clean dialysate drains excess fluid and toxics through the straw-like tubing by diffusion, carries the excess fluid and toxics with dialysate out of dialyzer 130 via output tube 220 and removes blood To purify. The dialysate leaving the output tube 220 is discarded after purifying the blood. In some cases, dirty blood flows from the arteries in the patient 200 to the pump 140 and further to the dialyzer 130. In this case, dirty blood flows from the input catheter 122 into the dialyzer 130, and clean blood returns from the dialyzer 130 to the patient 200 via the output catheter 124. At both ends of the dialyzer 130, spectrophotometric measurement means for defining a blood flow path, emitting radiation into the blood in the flow path, and detecting radiation passing through both the blood and the flow path are provided. ing. The spectrophotometer includes cuvette means for defining a blood flow path and emitter / detector means for emitting detection radiation. In the emitter / detector means, both a launching means for directing and emitting radiation and a detecting means for detecting radiation are arranged. In the prior art embodiment shown in FIG. 1, an example of the emitter / detector means is depicted as an emitter / detector device 100. A light emitter 102 is shown as an example of the launch means. The emitter / detector device 100 also has detection means, of which an optical detector 104 is depicted as an example. FIG. 1 shows a cuvette 10 as an example of the cuvette means. In the emitter / detector device 100, the portion of radiation directed at the cuvette 10 by the light emitter 102 and passing through both the internal blood and the cuvette 10 is detected by the light detector 104. As shown in FIG. 1, cuvettes 10 are provided at both ends of dialyzer 130. Each cuvette 10 has a light emitter 102 and a light detector 104 thereon. In a preferred embodiment of this system, light emitter 102 and light detector 104 are held together by a spring loaded C-clamp in emitter / detector light device 100. The emitter / detector means is electrically connected to the computing means. In one preferred embodiment of this system, as an example of the computing means, FIG. 1 shows that the computer 150 is electrically connected to the light emitter 102 and the light detector 104 on the emitter / detector device 100 and to the cable 120 or 128. It is drawn. The collection catheter 122 collects blood into the cuvette 10 placed in front of the input port 230 of the dialyzer 130. The emitter / detector device 100 at the input 230 of the dialyzer 130 irradiates the blood therein with radiation of the wavelength of electromagnetic radiation for spectrophotometric analysis to determine the concentration of the biological components that are present. The light detectors 104 at both the input 230 and the output 240 of the dialyzer 130 each transmit the detected radiation to the computer 150 via the cable 120 or 128. Computer 150 calculates the pre-dialysis (obtained via cable 120) and post-dialysis (obtained via cable 128) concentrations of the desired or desired biological component, respectively. The computer 150 then displays the resulting concentration of the biological component on the first display 152 and the second display 154, respectively, in an analog or digital manner. The calculation means, illustrated here as computer 150, preferably has a multiplexing function of calculating in real time and displaying some blood parameters of interest. 1. Single Injection Dilution In a first aspect, about 10 ml of saline is infused into the arterial tract in about 5 seconds. Immediately downstream of the injection point 15 (in the arterial tract), a disposable measuring blood chamber 10 is arranged. See FIG. Immediate changes in hematocrit (AH) occur due to dilution of whole blood with saline. Next, the area under the dilution curve is appropriately measured and calculated, see FIG. The access blood flow (Qa) is determined. Qi = V / K∫ (% ΔH) dt (1) where Qi = dialyzer blood flow rate (ml / min). K = conversion coefficient. Empirically determined to convert the rate of change of hematocrit to area and minute units. ∫ (% ΔH) dt = area under the hematocrit dilution curve (1) in FIG. V = volume of saline injected (usually 10 ml). If access recirculation (AR) is present, FIG. 3 is obtained. The following equation is used to determine AR. AR = (∫ (% ΔH) _Two dt / S∫ (% ΔH) ₁ dt) · 100 (2) where AR =% access recirculation when ultrafiltration is off. ∫ (% ΔH) _Two dt = area under curve 2, "measured area". ∫ (% ΔH) ₁ , Dt = area under curve 1, "calibration area". The area under the dilution curve 1, the "calibration area", represents 100% of the bolus of 10 ml saline that passes through the chamber and dilutes the blood in the passage of the light detector. The area under Dilution Curve 2, the "measured area", represents the amount of saline that has flowed into the shunt (or access) from the venous tract and recirculated back to the arterial tract twice through the light detector. The area under the dilution curve is measured during a specific time as follows. In FIG. 3, the injection of the saline solution is performed at time 0 seconds. The resulting line 51 transitions substantially flat until time 19 seconds, at which point the slope of the line 51 increases dramatically. At this point, the system starts measuring the area under the curve. The system continues to measure the area under curve 1 until the slope of line 51 changes from a negative slope to zero or a positive slope. In the figure, this change occurs at approximately time 41 seconds. At this point, the measurement of the area of the curve 1 is stopped, and the measurement of the area of the curve 2 is started. The measurement of curve 2 continues until the slope of line 51 changes from negative to zero. In FIG. 3, this change occurs at about time 78 seconds. At this point, the measurement of the area of the curve 2 stops. Knowing Qi (in ml / min) and the time (T) between dilution curves 1 and 2 in FIG. 3, the following equation can be used to calculate the amount of nominal fluid required for the dialyzer circuit. PDCV = Qi T (1/60) (3) Finally, to calculate the access blood flow, the arterial tract is placed “downstream” of the shunt's venous tract, inverted from the venous tract. Here, a bolus of 10 ml saline is infused into the arterial tract as usual (over 5 seconds) to obtain a dilution curve as shown in FIG. As in the case of the access recirculation determination, the recirculation (RAR) of the inverted access is calculated by the following equation. RAR = ∫ (% ΔH) _Two dt / ∫ (% ΔH) ₁ dt (4) Also, as in Equation 2 above, the process of ultrafiltration is turned off. Once the RAR is determined, the access blood flow Qa is calculated by the following equation. Qa = Qi (RAR ^-1 -1) (5) Thus, the calibration area (curve 1) and measurement area (curve 2) for a single injection of saline into the arterial tract immediately upstream of the disposable measurement blood chamber are determined. See FIGS. 3 and 4. The reference area, the calibration area, is already incorporated into the bolus of saline injected once, eliminating the need for two sensors. Alternatively, a conventionally used injection of a second saline solution may be performed. In that case, the first injection is a reference value measurement, and the second injection is a measurement injection. Single injection using a single detector is a significant improvement and has many advantages. For example, other methods typically require that two detectors be "tuned" exactly the same. In the double injection method, two injections must be performed each time in exactly the same amount and at the same given rate. Otherwise, the calibration area and the measurement area will be different, giving incorrect results. The above equation requires that the area under the hematocrit dilution curve, ∫ (% ΔH) dt, be accurately measured. The most common error in this measurement results from a change in the infusion rate of a saline bolus (typically 10 ml in 5 seconds). The actual rate of saline infusion can be calculated from basic parameters in arterial infusion. The changes (perturbations) caused by the transients induced by these injections, Qi, are compensated as in Equations 5a and 5b (obtained from Equation 1). Qi (after compensation) = V / [K (Area _m -Area _p )] (5a) However, Area _m = Measured area under hematocrit dilution curve. Area _p = Area of extrusion speed for saline injection. Area _p = [(-0.018) Qi (raw) + 1.22]-[2013 / span-Qi (raw) (0.3661)] (5b) where Qi (raw) = Area _m Based on the raw blood flow. span = the time (in seconds) from the beginning of the saline infusion to the end of the infusion. By compensating for the transients induced by the infusion rate in this way, more accurate blood flow, access recirculation, and access blood flow measurements can be made. 2. Second Aspect, ΔHematocrit Method Referring to FIG. 5, the access recirculation by the Δhematocrit method is obtained by the following mathematical calculation, and the mass (m) and the blood flow (Q) are calculated as follows. Can be balanced. ma + mr = mi (6) and Qa + Qr = Qi (7) Therefore, QaHa + QrHo = QiHi (8) (where Qo = Qi-UFR) because QiHi = QoHo = (Qi-UFR) Ho (9) and Ho = ( Qi / (Qi-UFR)) Hi (10) However, when R = Qr / Qi and equation 8 is divided by Qi, the following equation is obtained. Hi / Ha = (1-R) [1-R (Qi / Qi-UFR)] ^-1 (11) Therefore, the following equation for determining access recirculation (AR) by the Δhematocrit value method is obtained. AR = 100 (Hi-Ha) [Qi / Qi-UFR)) Hi-Ha] ^-1 (12) From equation 12, changing the blood flow rate, Qi, or changing the ultrafiltration (UFR) of the dialyzer causes a change in the hematocrit value, and thus a direct measurement of access recirculation is made. You can see that. The case where the access blood flow Qa is obtained by the Δ hematocrit value method will be described with reference to FIG. Since the hematocrit must be balanced around the piping / dialyzer circuit, the following equation holds: QaHa + QoHo = Hi (Qa + Qo) (13) However, QiHi = QoHo and (Qo = Qi-UFR) (14) Therefore, QaHa + QiHi = Hi (Qa + Qi-UFR) (15) Also, Hi / Ha = Qa (Qa-UFR) (16) Therefore, Qa = Hi (UFR) / (Hi−Ha) (17) From equation 17, it can be seen that Qa obtained by the Δhematocrit value method does not depend on the blood flow Qi of the dialyzer. Therefore, the access blood flow can be calculated directly by simply changing the ultrafiltration (UFR). As an example, the value of Qa can be determined as follows. Assume UFR = 0 ml / min, ie ml / min. According to equation (17), Qa is 0 ml / min. Further, since UFR = 0 ml / min, the hematocrit value Ha of the access is 30.0. This is the basic value of Ha. When the UFR rises, for example to 30 ml / min, the hematocrit of the arterial tract measured after a short time (3 or 4 minutes), Hi, is about 31.0. Therefore, according to Equation 17, Qa = 31 (30) / (31-30) = 930 ml / min. Utilizing instantaneous hematocrit monitoring, the AR hematocrit method described above can directly and directly measure AR and Qa. If AR and Qa are measured using the Δhematocrit method together with a blood volume monitor (relative measurement of hematocrit), a direct and immediate result can be obtained. However, the results are not very accurate because hematocrit values are measured relatively. It must be emphasized again that U.S. Pat. No. 5,372,136 shows a method for measuring absolute hematocrit. The method described in the second aspect of the invention is intended to incorporate the relative measurement of hematocrit with the optical, conductive or ultrasonic single wavelength measurement of BV measurement. Therefore, simply changing Qi or UFR to measure AR or simply changing UFR to measure Qa is a very important, new and unique concept. U.S. Pat. No. 5,372,136 clearly describes an operating means by which hematocrit values can be measured instantaneously and continuously and can be used with the disposable blood chambers described above. Although the above description relates to the non-invasive analysis of hemodynamic information of access blood flow, it is understood that the circuits and algorithms described above can be applied to the analysis of other fluid parameters. Like. The present invention may be embodied in other specific forms without departing from its spirit and essential characteristics. The embodiments described above are merely illustrative in all respects and do not limit the invention.

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), OA (BF, BJ, CF) , CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (GH, KE, LS, MW, S D, SZ, UG, ZW), EA (AM, AZ, BY, KG) , KZ, MD, RU, TJ, TM), AL, AM, AT , AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, F I, GB, GE, GH, HU, IL, IS, JP, KE , KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, M X, NO, NZ, PL, PT, RO, RU, SD, SE , SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZW (72) Inventor Miller David Earl             United States Vermont 84050             Morgan North Trapper's Loop               6551

Claims (1)

[Claims] 1. Measuring access recirculation in dialysis systems with arterial and venous lines   In the method for     A step of confirming that ultrafiltration is off,     Apply a predetermined amount of saline to the injection site in the arterial tract   Introducing over a period of time,     Measuring a percentage change in hematocrit during a first period;     Percentage change in hematocrit for a second period that occurs after the first period   Measuring the G value, and     Measuring the change in hematocrit value for the second period   Generates a signal that is directly proportional to access recirculation, as compared to a measured change in lit value   Process,   Having a method. 2. The method of claim 1, further comprising:     A song showing the percentage change in hematocrit during the first and second periods   Area under the line (Area_mMeasuring),     Determining the uncorrected blood flow (Qi (raw));     Time in seconds from the beginning of Qi (raw) and solution injection to the end of injection   Area of extrusion rate of solution injection (Area_p)   About     Measuring the amount of saline injected,     The amount of saline injected (Area_m-Area_p) X conversion factor,   Obtaining a result indicating the corrected blood flow,   Having a method. 3. Uncorrected blood flow (Qi (raw)) is Area_mClaims calculated from the value of   3. The method according to 2. 4. Area_pThe process of finding   Formula Area_p= [(-0.018) Qi (raw) + 1.22]                   • Solve [-(2013 / span) -Qi (raw) (0.3661)]   3. The method of claim 2, comprising: 5. The method of claim 1, further comprising:     The signal is multiplied by a predetermined factor to obtain a percentage change in access recirculation.   A step of obtaining a count value. 6. The method according to claim 5, wherein the coefficient is 100. 7. The method of claim 1, further comprising:     Place a blood chamber in the arterial tract downstream from the point of introduction of saline into the arterial tract   Process, and     Each of the two measurement steps is determined by determining the hematocrit of blood passing through the chamber.   Performing photometric measurement. 8. Measuring access recirculation in dialysis systems with arterial and venous lines   In the method for     A predetermined amount of saline is injected into the arterial tract for a predetermined period   The process of introducing     Measuring a percentage change in hematocrit during a first period;     The amount of saline introduced is a measure of the change in hematocrit during the first period.   Is compared with a product of a predetermined conversion factor,   Generating a number,   Having a method. 9. Measure the nominal solution volume of the dialysis circuit in a dialysis system with arterial and venous lines.   In the method     A predetermined amount of saline is introduced into the arterial tract for a first period   Process,     Measuring a percentage change in hematocrit for a second period;     Measuring a percentage change in hematocrit during a third period;     The amount of saline introduced into the arterial tract is determined by the change in hematocrit during the first period.   Compared to the product of the measured value of dialysis and a predetermined conversion factor,   Generating a signal indicative of the quantity; and     The value obtained by multiplying the blood flow rate of the dialyzer by the sum of the first, second and third periods   Dividing by 60 to generate a signal indicative of the nominal solution volume of the dialysis circuit;   Having a method. Ten. Measuring access blood flow in dialysis systems with arterial and venous lines   In the law,     Introduce a predetermined amount of saline into the venous tract for a first period   Process,     The step of determining the blood flow rate of the dialyzer,     Measuring a percentage change in hematocrit for a second period;     Measuring a percentage change in hematocrit during a third period;     The measured change in hematocrit during the third period is compared to the hematocrit during the second period.   In comparison to the measured value of the change in the access value, the inverted access recirculation (RAR)   Generating an example signal; and     Subtract 1 from the reciprocal of RAR, multiply the obtained value by the blood flow rate of the dialyzer, and   Generating a signal indicative of cess blood flow;   Having a method. 11． Induced by injection when injecting solution into arterial and venous tracts   In a method for removing transients,     A step of confirming that ultrafiltration is off,     Apply a predetermined amount of saline, at least to the arterial and venous   One of which is introduced into one of them for a predetermined period,     Area under the curve showing the percentage change in hematocrit over a period of time   (Area_mMeasuring),     Determining the uncorrected blood flow (Qi (raw));     Time in seconds from the beginning of Qi (raw) and solution injection to the end of injection   Area of extrusion rate of solution injection (Area_p)   About     Measuring the amount of saline injected,     The amount of saline injected (Area_m-Area_p) X conversion factor,   Obtaining a result indicating the corrected blood flow,   Having a method. 12． Uncorrected blood flow (Qi (raw)) is Area_mClaims calculated from the value of   12. The method according to 11. 13. Area_pThe process of finding   Formula Area_p= [(-0.018) Qi (raw) + 1.22]                   -Solve [-(2013 / span) -Qi (raw) (0.3661)]   12. The method according to claim 11, comprising: 14. To determine access blood flow in dialysis systems with arterial and venous lines   In the method     A predetermined amount of saline is injected into a vein for a predetermined period.   The process of introducing     Setting an initial ultrafiltration (UFR),     Determining the access hematocrit value in the initial UFR;     Changing the value of UFR to a second UFR;     Measuring the arterial hematocrit value in the second UFR;     The arterial hematocrit value is multiplied by the second UFR, and the obtained value is used as the arterial hematocrit.   Access blood flow divided by crit value minus access hematocrit value   The step of calculating   Having a method. 15． Access Recirculation (AR) in a dialysis system with arterial and venous lines   In a method for determining a percentage value,     Apply a predetermined amount of saline to the injection site in the IV vein.   Process to be introduced over a period     Setting an initial ultrafiltration (UFR),     Measuring the initial dialyzer blood flow (Q);     Access hematocrit (H) at initial UFR or initial dialyzer blood flow   a) determining a)     Changing the value of UFR or dialyzer blood flow to a second value;     Measuring the hematocrit value (Hi) of the artery with the second value;     The access recirculation (AR) percentage is determined by the UFR or dialyzer blood flow.   Calculating as a function of the change in displacement,   Having a method. 16． 16. The method of claim 15, wherein measuring the dialyzer blood flow.   Is     Measuring a percentage change in hematocrit during a first period;     The amount of saline introduced is a measure of the change in hematocrit during the first period.   Is compared with a product of a predetermined conversion factor,   Generating a number,   Having a method. 17． 16. The method of claim 15, wherein the access recirculation percentage value   The process of calculating     Formula AR = 100 (Hi-Ha) [Qi / Qi-UFR)) Hi-Ha]^-1   A method having a step of solving.