KR100498628B1 - System and method for noninvasive hemodynamic measurements in hemodialysis shunts - Google Patents

Abstract

The passage of the passage of the short circuit is quantitatively determined by a method of injecting a standard solution such as saline into the blood stream of the patient 200 upstream of the short circuit. At one of the passage lines, the change in hematocrit (delta H) is measured over time by photometry. The electronic circuit 150 receives the signal from the detector 100 and compares the signal over time with the integral area of the delta H with the standard solution first passing through the passage of the recycle solution and displayed on the recycle display 152.

Description

Non-invasive hemodynamic measurement system and method in hemodialysis paragraph {SYSTEM AND METHOD FOR NONINVASIVE HEMODYNAMIC MEASUREMENTS IN HEMODIALYSIS SHUNTS}

The present invention relates to non-invasive measurement systems and methods for hemodynamic access, passage recirculation and blood flow measurement during hemodialysis.

More specifically, the present invention relates to a non-invasive spectrophotometric system and method for quantitatively measuring lateral recirculation, passage blood flow rate, dialysis blood flow rate, and the amount of priming fluid required for hemodialysis channels. do.

Modern medical technology uses a variety of methods and indicators to assess the condition of patients, especially patients with catapults.

Hemodialysis is a required process for removing biological debris from artificial kidneys that replace the kidney function of patients.

If the human kidney can no longer function to remove urea, potassium, excess water, etc., the patient's blood must be removed through the vascular connection and filtered through an artificial kidney or dialysis machine.

In the process, the blood passes through the dialyzer and is purified and returned to the patient's normal circulation.

Pathways to the patient's circulatory system are achieved using surgically implanted shorts or fistulas.

This "path area" is usually on the arm, leg, or neck.

The needle is generally placed in the "path" in such a way as to easily remove blood upstream of the "artery" or the dialyzer and to return purified blood generally downstream of the first needle location on the "vein" side.

Unfortunately, fistulas and shorts are often clumped or narrowed as they age.

As a result, blood flow reduction eventually requires angioplasty or short-circuit replacement surgery.

A portion of the purified dialysis blood is forced back to the arterial bleeding because of a short or "stuck" short circuit and is therefore recirculated and redialyzed; This is called "path recirculation".

Continuous recirculation of the clarified blood prevents the patient's remaining circulating blood from properly purifying and eventually delivers adequate dialysis to the patient.

Therefore, because of the possibility of more than the amount of dialysis resulting from the recirculation reflux of the purified blood directly to the depression, various methods and techniques have been devised to determine:

(1) passage recyclability or percentage;

(2) the actual blood flow in the paragraph;

(3) dialyzer blood flow rate

Medical practitioners need to know both qualitatively and quantitatively to determine the degree of entanglement or stenosis.

These variables are required to predict when passage will fail and also to determine the need for surgical correction of the passage.

Blood flow Q was measured by Ficke dilution published by the so-called ACGuyton (Textbook of Medical Physiology, Sixth Edition, pg 287. 1981), which indicates that blood flow Q divides the volume of injected diluent by the diluent average concentration It is equal to the product of the diluent passing through.

Dilution curves are obtained by measuring the changes observed continuously during the injection time given the physical parameters of the blood.

The concentration change of the diluent (or medium) is measured over time.

Hester, R. L. et. al is American Journal of Kidney Disease 20: 6, 1992, pp. 598-602 reported that restoring the dialysis vessel vessels could improve blood circulation.

Krivitski's European patent application WO9608305A1 announced that the repair of blood vessels (causing forced recirculation) can measure the actual blood flow in a short circuit.

One method is to utilize color-coded double sonography to measure passage blood flow. However, this technique is expensive.

And the operator's mistake affects the measurement, requiring a high degree of expertise.

In addition, changes in vessel diameter and Doppler flow angle are also significant constraints on this measurement method.

Another method is to intravenously inject a saline solution and photodetect the change in intensity of light passing through the tube at a position higher than the injection point (US Pat. No. 5,312,550).

In addition, there is also a method of injecting physiological saline tablets into the arterial and venous dialysis tube and measuring the change in the ultrasonic speed (US Patent No. 5,453,576).

The technique is sensitive to internal factors that cause temperature changes, plasma protein levels, and blood density changes.

More importantly, however, the measurement of absolute ultrasonic velocity changes is influenced by internal blood factors and also by the unknown mechanical properties of the connector itself.

To compensate for these internal and external physical problems, another saline solution is compensated for infusion into the opposite connector, ie the arterial or venous line, causing a relative change in dilution due to the saline tablet.

Thus, the unknown ultrasonic properties and other physical dimensional properties of the connector can be minimized.

The standard method of passage recirculation of the present invention takes three nitrogen urea samples from a patient during dialysis.

However, in addition to taking blood samples from patients, maintaining nursing time, research costs, and adequate blood flow during the actual sampling process is also very important for accurate nitrogen element measurement.

Thus, there is a continuing need for systems and methods for non-invasive and quantitative measurement of hemodynamic pathway blood flow and blood recirculation parameters.

1 shows a conventional dialyzer connection circuit.

FIG. 2 shows a graph of hematocrit% ΔH (or% Δ blood volume (BV)) versus time after injection of 10 ml saline into the bloodstream upstream of the paragraph.

FIG. 3 shows one injection dilution curve with passage recirculation and attention to secondary area (curve 2) after primary area (curve 1).

4 shows one injection dilution curve in reflux artery and vein connections that causes forced (or reflux) recirculation.

5 is a graphical representation of the dialysis circuit in terms of mass flow in the same arterial and venous direction.

6 is a graphical representation of the dialysis circuit in terms of mass flow in the direction of reflux arterial and venous lines.

It is therefore an object of the present invention to provide a non-invasive pathway hemodynamic observation system and method that minimizes nursing time and does not require careful blood collection.

It is yet another object of the present invention to provide a system and method for displaying immediate and continuous visible information regarding hemodynamic pathway data of saline dilution.

Another object is to provide a system and method for repeatedly and reliably and non-invasively measuring hemodynamic pathway fluidity under changing conditions (including changes in ultrafiltration rate, patient posture, connector type and dimensions). , And also various dialysis membranes and dialysis delivery systems.).

Another object of the present invention is to provide a means and a method for quantitatively measuring the blood flow rate (volume) Q _i actually passing through the dialyzer.

The present invention also provides a dilution concentration-time curve which the operator can visually see in visible real-time display means.

As another object the present invention also provides a system and method for instantaneous quantitative measurement of the actual volume of fluid required for the initialization of a dialysis machine circuit.

Similarly, it is another object of the present invention to provide a system and method for measuring passage blood flow and passage recirculation that does not require saline injection.

This is, for example, a method of changing the ultrafiltration (UFR) or the dialyzer blood flow rate.

It is also an object to provide a system and method for measuring dialysis blood flow parameters.

These and other objects and the advantages of the invention appear in more detail in the context of the claims for carrying out the invention.

In one aspect of the invention, passage recirculation of the short circuit is quantitatively determined by injecting a standard solution, such as saline solution, into the patient's bloodstream upstream of the short circuit.

At one point in the passageway, the hematocrit change (ΔH) over time is photometric measured.

The electronic circuit compares the integral area of ΔH over the time of the initial flow reference and the recycled passage through the detector signal, and also provides nearly constant channel recirculation.

In another aspect, channel recirculation or channel blood flow is quantitatively measured without solution injection into the bloodstream.

In this respect, the size of the passage recirculation or passage blood flow is quantitatively measured by measuring the change in dialysis blood flow or ultrafiltration (UFR) and the resulting change in blood concentration.

In this technique, the concentration of blood components is measured as a function of the dialyzer blood- or UFR, and the electronic circuitry converts these measurements into quantitative determinations of channel recirculation or channel blood flow for display almost immediately.

In one preferred embodiment the blood component measured is red blood cells.

In one preferred embodiment, the measurements are carried out using the devices disclosed in US Pat. Nos. 5,456,253 and 5,372,136, as described below.

Both patents are part of the present invention.

In one embodiment, hematocrit is measured in blood flow through a cuvette located in the passageway.

In some embodiments, hematocrit is measured using a device and signal conditioning method disclosed in US Pat. No. 5,372,136.

The part number is the same as that described in FIG. 1 of US Pat. No. 5,456,253.

In hemodialysis, blood is taken from the absorbing catheter, for example the feeding catheter 122, as shown in FIG.

The supply catheter 122 is intravenously inserted into the site 180 of the patient 200 and forms a blood pathway upstream of the blood filter for filtering impurities in the blood.

The blood filter is also referred to as dialysis machine 130.

Impure blood flows out of the artery of patient 200 with pump 140.

In the pump 140, blood enters the dialyzer 130.

The dialysis machine 130 is provided with an inlet 230 and an outlet 240.

The pump 140 moves impure blood into the inlet 230 and flows out of the outlet 240 through the dialyzer 130.

In particular, impure blood in the feed catheter 122 is delivered towards the inlet 230 of the dialyzer 130.

The blood purified while passing through the dialysis machine 130 may process heparin drip and the like in the hemodialysis related device 300.

The purified blood enters the patient 200 after the dialysis treatment by the discharge catheter 124.

The discharge catheter 124 is also intravenously inserted into the site 180 of the patient 200 to form a blood path descending from the dialyzer 130, and the blood discharged out of the dialyzer 130 to the patient 200. Allow it to be supplied again.

As described above, the hemodialysis process purifies the blood of the patient 200 using the blood filter or the dialysis machine 130.

When the blood passes through the dialyzer 130, it enters into a sawtoothed tube (not shown) that serves as a passage of impure blood within the dialyzer 130.

The serrated tube removes toxins and excess liquid through diffusion.

The excess liquid in impure blood is, for example, water and the toxins include blood nitrogen urea (BUN) and potassium.

The excess liquid and toxin passed through the ultrafiltration process are removed by a clean dialysate fluid, which is a liquid of chemicals and water.

The dialysate enters the dialyzer 130 connected to the supply pipe 210 from the hybrid controller tank 170.

The dialysate descends toward the dialyzer 130 and surrounds the sawtooth tube therein.

The dialysate collects the fluid and toxin passing through the sawtooth tube by the diffusion method to remove excess fluid and toxin along with the dialysate from the dialyzer 130 through the outlet tube 220 and purify the blood.

Then, the dialysate exiting the outlet pipe 220 after the blood purification is discarded out.

Sometimes, impure blood flows out of the artery of the patient 200 and enters the dialysis machine 130 through the pump 140.

Impure blood exits the inlet catheter 122 and enters the dialyzer 130 and the purified blood exits the dialyzer 130 through the exit catheter 124 and returns back to the patient 200.

Spectrophotometer means installed at both ends of the dialyzer 130 is to limit the blood flow path and to emit radiation into the blood in the flow path to detect radiation penetrating the blood and flow path.

This spectrophotometer means comprises cuvette means for defining the blood flow path and also emitter / detector means for emitting and detecting radiation.

Inside the emitter / detector means are both an emitting means for determining the direction of radiation and a detector means for detecting radiation.

In a known embodiment such as in FIG. 1, device 100 is shown as an example of emitter / detector means.

The emitter means is for example a light emitter 102.

The emitter / detector device 100 also includes a light detector 104 as detection means.

The cuvette means is the cuvette 10 of FIG.

The emitter / detector 100 allows the light detector 104 to detect some of the radiation directed towards the cuvette 10 by the light emitter 102 and passes through both blood and the cuvette 10.

As shown in FIG. 1, the cuvette 10 is installed at either end of the dialysis machine 130.

Each cuvette 10 is equipped with a light emitter 102 and a light detector 104.

In a preferred device implementation, the light emitter 102 and the light detector 104 are joined together by a C-clamped spring inserted into the emitter / detector 100.

The emitter / detector means is electrically connected to the calculation means.

In one preferred embodiment, the calculator means is a computer 150 electrically connected to the light emitter 102 and the light detector 104 of the emitter / detector 100 by cable 120 or 128 as in FIG. )to be.

Absorption catheter 122 sends blood to the cuvette 10 in front of the inlet 230 of the dialyzer 130.

The emitter / detector 100 mounted at the inlet 230 of the dialyzer 130 applies electromagnetic radiation to the blood and analyzes it by spectrophotometry to obtain the concentration of the desired biological component.

Each photodetector 104 at the inlet 230 and outlet 240 of the dialyzer 130 sends the detected radiation to the computer 150 via cable 120 or 128.

Computer 150 calculates both predialysis (via cable 120) and postdialysis (via cable 128) concentrations of the desired biological component.

The computer 150 then displays the induced concentration of the biological component in analog or digital form in each of the first display 152 and the second display 154.

The calculation means has a complex function such as computer 150 that can simultaneously perform real-time calculations and display of multiple blood parameters.

1. First injection dilution technique

In the first aspect, about 10 ml of saline is injected into the artery for 5 seconds.

The measuring cuvette 10 immediately descends from the injection position 15 (in the artery) as shown in FIG. 1.

Changes in hematocrit (AH) occur immediately because the whole blood is diluted by saline.

Therefore, if the area under the dilution curve is accurately measured and calculated as shown in FIG. 2 (Ficke principle), the dialysis machine blood flow rate Q _i , the passage recirculation AR, and the passage blood flow rate Q _a are measured in the following manner. .

Q _i = V / K∫ (% △ H) dt (1)

here

Q _i = dialyzer blood flow rate, ml / min

K = conversion factor, hematocrit in percentage, in area and minutes

      This value is for conversion and is determined experimentally.

∫ (% ΔH) dt = area under the hematocrit dilution curve (1) of FIG.

V = brine volume (volume) (typically 10 ml)

If there is passage recirculation AR, the curve of FIG. 3 can be obtained.

To determine the AR, use the following equation:

AR = (∫ (% △ H) ₂ dt / ∫ (% △ H) ₁ dt) 100 (2)

here

AR =% passage recycle

∫ (% △ H) ₂ dt = area under curve 2, "measurement area"

∫ (% △ H) ₁ dt = area under curve 1, "calculated area"

The area under the dilution curve (1) is called the “calculated area” and is a 100% salt solution of 10 ml that passes through the chamber and dilutes blood in the optical detector path.

The area under the dilution curve (2) is called the "measurement area" and indicates the amount of saline that is "recirculated" from the vein into a short circuit (or passage) and "returned" to the artery, and passes the optical detector secondarily.

The area under the dilution curves is measured in the following manner for a specific period

In Fig. 3, the brine solution is injected at 0 seconds.

At this time, the line 51 is almost inclined and increases rapidly when it reaches 19 seconds.

At this point, the area under the curve 1 is measured.

The area under the curve 1 is continuously measured until the slope of the line 51 changes from a negative value to a positive value that occurs when it is zero or about 41 seconds.

At the point of 41 seconds, measurement of the area under the curve 1 is stopped, and measurement of the area under the curve 2 is started.

The area measurement of curve 2 continues as shown in Fig. 3 until 78 seconds, when the slope of the line 51 changes from a negative value to a zero point.

At this point, the measurement of the area of the curve 2 is stopped.

If the Q _i value (ml / min) and the time T between the dilution curves (1) and (2) of FIG. 3 are known, the volume PDCV of the initial dialysis circuit can be calculated as follows.

PDCV = Q _i T (l / 60) (3)

Finally, the arterial line is placed in the opposite direction to the venous line and installed "downstream" of the short circuit to calculate passage blood flow.

10 ml saline tablet (supplied for 5 seconds) is injected into the artery line to obtain a dilution curve as shown in FIG.

In determining passage recirculation, the reverse passage recirculation (RAR) is calculated according to the following equation:

RAR = ∫ (% △ H) ₂ dt / ∫ (% △ H) ₁ dt (4)

As in equation (2), there is no ultrafiltration.

Once the RAR is determined, the channel blood flow rate Q _a is calculated from:

^{_{Q a = Q i (RAR -1}} -1) (5)

Thus, upon one saline injection into the artery line, the compensation area (curve 1) and measurement area (curve 2) are obtained upstream of the vascular chamber for measurement, as in FIGS. 3 and 4.

The reference or compensation area is already included in the area of the single injection saline tablet without a double sensor or without the usual secondary saline injection (where one injection is for reference measurement and secondary injection is measurement injection).

One-time saline injection using a single detector is a major improvement and has several advantages.

For example, other methods require the two detectors to be adjusted exactly the same.

In the double injection method, the same amount is injected twice at the same speed. Otherwise, the compensation area and the measurement area are different, resulting in an error in the result.

In the above equation, the area ∫ (% ΔH) dt under the hematocrit dilution curve should be measured accurately.

The most common measurement error is due to a change in the rate of injection of the salt tablet (usually 10 ml for 5 seconds).

The actual saline injection rate can be calculated from a parameter based on the time of arterial infusion.

The resulting change (variation) Q is due to the change at injection, which is compensated for as shown in equations (5a) and (5b) (derived from equation 1).

Q _i (correction) = V / [K (area _m minus area _p )] (5a)

Where _m = area under the hematocrit dilution curve

Area _p = area of extrusion velocity during saline injection

Area _p = [(-0.018) Q _i (first value) +1.22] [(2013 / span) -Q _i (first value) (0.3661)] (5b)

here,

Q _i (initial value) = initial blood flow rate based on area _m .

Span = time interval from start to end of saline injection, in seconds.

Compensation for changes in infusion rate can provide more accurate blood flow, channel recirculation, and channel blood flow measurements.

2. Secondary side, △ Hematocrit method

Referring to Figure 5, it is possible to measure the passage recirculation using the ΔH hematocrit method in the following equation, where the balance of mass (m) and blood flow rate (Q) is as follows:

m _a + m _r = m _i (6)

And Q _a + Q _r = Q _i (7)

Therefore, Q _a H _a + Q _r H _o = Q _i H _i (8)

Where Q _o = Q _i -UFR

Where Q _i H _i = Q _o H _o (9)

= (Q _i -UFR) H _o

In addition, H _o = (Q _i / (Q _i -UFR)) H _i (10)

However, R = Q _r / Q _i , so dividing Eq. (8) by Q _i gives:

H _i / H _a = (1-R) [1-R (Q _i / (Q _i -UFR))] ^-1 (11)

Thus, the following formula is obtained to determine passage recirculation according to the Hematocrit method:

AR = 100 (H _i -H _a ) [(Q _i / (Q _i -UFR)) H _i -H _a ] ^-1 (12)

It can be seen from Equation (12) that a change in dialysis blood flow Q _i or a change in ultrafiltration (UFR) results in a change in hematocrit (thus, a direct measurement of passage recirculation can be determined).

In order to determine the passage blood flow rate Q _a by the Δhematocrit method, it can be seen that the arterial line and the venous line are opposite to each other as shown in FIG. 6.

Only by maintaining the hematocrit equilibrium of the connector / dialysis circuit can the following equation be applied:

Q _a H _a + Q _o H _o = H _i (Q _a + Q _o ) (13)

However, Q _i H _i = Q _o H _o , (also Q _o = Q _i -UFR) (14)

In addition, Q _a H _a + Q _i H _i = H _i (Q _a + Q _i -UFR) (15)

H _i / H _a = Q _a (Q _a -UFR) (16)

Thus Q _a = H _i (UFR) / (H _i -H _a ) (17)

In equation (17), Q _a is independent of the dialysis blood flow rate Q _i according to the Δhematocrit method.

Therefore, the passage blood flow can be directly calculated by simply changing the ultrafiltration amount (UFR).

For example, the Q _a value is determined in the following manner.

Assume UFR = 0 ml / min.

According to equation (17), Q _a is equal to 0 ml / min.

If UFR = 0 ml / min, the passage hematocrit H _a is determined to be 30.0.

This is the lowest value of H _a .

If the UFR increases, for example to 30 ml / min, the hematocrit value H _i of the arterial line is 31.0 when measured after a short period (3 or 4 minutes).

_{Thus, Q a = 31 (30)} / (31-30) = 930 ml / min according to the equation (17).

Using an instantaneous hematocrit observer, AR and Q _i are measured instantaneously or directly by the above Δhematocrit method.

Using the hematocrit method with a blood volume observer (relative measurement of hematocrit), AR and Q _a can be measured to obtain instantaneous and direct results.

However, the result is not accurate because it is a relative measurement of hematocrit.

While US Pat. No. 5,372,136 shows the absolute measurement of hematocrit, the method and technique disclosed in the secondary aspect of the present invention can be used to obtain a relative measurement of hematocrit (ΔAB), and also to use a single wavelength optical method or inductive measurement method. Alternatively, BV can be measured by ultrasonic method.

Thus, simply measuring Q _i or UFR to measure AR or changing UFR to measure Q _a is a novel and unique concept.

U.S. Patent No. 5,372,136 discloses an operation means capable of instantaneous and continuous measurement of hematocrit and using together the above-described blood processing vessel.

While the above review concerns the analysis of non-invasive hemodynamic pathway flow information, it is clear that the above circuits and algorithms can be suitably used for the analysis of other rheological parameters.

The invention can be embodied in other specific forms without departing from the scope of the essential features, and the foregoing implementations are merely examples and are not limited thereto.

Claims (25)

A device for determining the passage blood flow rate (Q _a ) of a dialysis system with arterial and venous connections reflux, Means (10,100) for measuring predialyzer hematocrit (H _a ) at _a selected initial ultrafiltration (UFR); Means (10,100) for measuring predialysis hematocrit (H _i ) in the primary UFR and in the secondary UFR; And And means (150) for solving the equation Q _a = H _i (UFR) / (H _i -H _a ). A device for determining percent passage recirculation (AR) of a dialysis system with arterial and venous connections, Means (10,100) for measuring an initial dialyzer blood flow rate (Q _i ); It means for determining a passage hematocrit (H _a) at a selected early or early UFR dialyzer blood flow rate (150); Means (10,100) for measuring arterial hematocrit (H _i ) at dialysis blood flow rate different from the second or initial value of UFR; And And means for calculating percent channel recirculation (AR) as a function of a change in either the UFR or the dialyzer blood flow rate. The method of claim 2, Means for measuring the dialyzer blood flow rate are: Means (10,100) for measuring a change in hematocrit percentage during the first time period; And Means for comparing the volume of saline supplied and a predetermined conversion factor for the result of the measured change in hematocrit percentage during the first period to obtain a signal indicating the dialyzer blood flow rate Device. The method of claim 2, The means for calculating the percent passage recycle includes means 150 for solving the equation AR = 100 (H _i -H _a ) [(Q _i / (Qi -UFR)) H _i -H _a ] ^-1 . Device characterized in that. A device for measuring passage recirculation of dialysis systems with arterial and venous connections and stopping superfiltration, Means (10,100) for measuring a percentage change in hematocrit during a second period of time following a change in blood parameter in the arterial connection line during the first period of time; Means (10,00) for measuring a percentage change in hematocrit during the third period that occurs after the second period; And Means for comparing the measured hematocrit percentage change over the third time period to the outcome of the measured hematocrit percentage change over the second time period to obtain a signal directly proportional to the passage recirculation or backflow passage recirculation (RAR). Apparatus comprising a). The method of claim 5, And means for subtracting 1 from the reciprocal of the RAR and multiplying the result by the dialyzer blood flow to obtain a signal indicative of the passage blood flow. The method of claim 5, And means (150) for multiplying the signal by a predetermined coefficient to obtain a percentage change in the passage recycling. The method of claim 7, wherein And the count value is 100. The method of claim 5, The change in blood parameters is a result of supplying saline into an injection site in an arterial connection. An apparatus for determining passage blood flow in a dialysis system having arterial and venous connections, Means for determining the pathway hematocrit in the initial UFR; Means (10,100) for measuring arterial hematocrit at a second UFR that is different from the initial UFR; And And means (150) for multiplying the arterial hematocrit with the second UFR and dividing the result by the arterial hematocrit and subtracting the passage hematocrit therein to calculate the passage blood flow. The method of claim 9, Means (10,100) for measuring an area (area _m ) under a curve indicating a percentage change in hematocrit for the first and second periods; Means 150 for determining an incorrect blood flow rate Q _i (initial value); Means (150) for determining, in seconds, the solution forced injection area (area _p ) as a function of the saline injection start Q (initial value) and the span if the span is equal to the period from the start of the saline injection to the end; Means for measuring the volume of injected saline (10,100); And And means (150) for dividing the volume of saline injected by the conversion factor of (area _m -area _p ) times in order to obtain a result representing an accurate blood flow rate. The method of claim 11, Inaccurate blood flow rate (Q _i (initial value)) is determined from the area _m value. The method of claim 11, The means for determining the area _p is a means 150 for solving the equation area _p = [(-0.018) Q _i (initial value) + 1.22] [-(2013 / span)-Q _i (initial value) (0.3661)]. Apparatus comprising a). The method of claim 10, And means (150) for multiplying the signal with a predetermined coefficient to obtain a percentage change in passage recycling. The method of claim 14, And said count value is one hundred. The method of claim 10, Means for measuring the percentage change in hematocrit during the first period and means for measuring the percentage change in hematocrit during the second period are respectively used for blood entering the arterial connection line through the blood chamber in the arterial connection line downstream of the saline feed point. Means (10,100) for measuring hematocrit in a photometric manner. A device for measuring the volume of an initial dialysis circuit of a dialysis system with arterial and venous connections, Means (10,100) for measuring a percentage change in hematocrit during a second period of time following a change in blood parameter in the arterial connection line during the first period of time; Means (10,100) for measuring a percentage change in hematocrit during a third period of time following a change in blood parameter in the arterial connection line during the first period of time;  Means (150) for comparing the changed blood parameters and the predetermined conversion coefficients in the arterial connection lines to the results of the measured hematocrit changes during the first time period to obtain a signal indicating the dialyzer blood flow rate; And And means (150) for multiplying the dialyzer blood flow by the sum of the first, second and third periods and dividing the result by 60 to obtain a signal indicating the initial dialyzer circuit volume. . The method of claim 17, The change in blood parameters is a result of supplying saline into the injection site in the arterial connection. A device for measuring passage blood flow in a dialysis system having arterial and venous connections, Means (10,150) for measuring a percentage change in hematocrit during a second period of time following a change in blood parameter in the venous connection line during the first period of time; Means (10,150) for measuring a percentage change in hematocrit for a third period of time following a change in blood parameter in the venous line during the first period; Means 150 for comparing the measured hematocrit changes over the third period to the measured hematocrit changes over the second period to obtain a signal directly proportional to the reversed passage recycling (RAR); And And means (150) for subtracting 1 from the reciprocal of the RAR and multiplying the result with the dialyzer blood flow to obtain a signal indicating the passage blood flow rate. The method of claim 19, The change in blood parameters is a result of supplying saline into the injection site in the arterial connection. A device for measuring the dialyzer blood flow in a dialysis system with arterial and venous connections, Means (10,100) for measuring a percentage change in hematocrit during the first period of time after supplying a predetermined amount of saline into the arterial connection line for a predetermined period of time; And And means (150) for comparing the volume of saline supplied and a predetermined conversion factor for the measured hematocrit changes over the first period of time to obtain a signal indicating the dialyzer blood flow rate. A device that eliminates injection-induced transients when a solution is injected into an artery or vein connection with a stop of ultrafiltration, Means (10,100) for measuring an area under the curve (area _m ) indicating a percentage change in hematocrit over a period of time following the supply of a predetermined amount of solution to at least one of the arterial and venous lines for a period of time; Means 150 for determining an incorrect blood flow rate Q _i (initial value); In seconds, means 150 for determining Q (initial value) and the forced solution injection area (area _p ) as a function of the span if the span is equal to the period from start to end of solution injection; Means (10,100) for measuring the volume of the injected solution; And And means (150) for dividing the volume of the injected solution by the conversion factor of (area _m -area _p ) times in order to obtain a result indicating an accurate blood flow rate. The method of claim 22, Inaccurate blood flow rate (Q _i (initial value)) is determined from the area _m value. The method of claim 22, The means for determining the area _p is a means 150 for solving the equation area _p = [(-0.018) Q _i (initial value) + 1.22] [-(2013 / span)-Q _i (initial value) (0.3661)]. Apparatus comprising a). An apparatus for determining passage blood flow in a dialysis system having arterial and venous connections, Means (150) for determining passage hematocrit at an initial ultrafiltration flow rate (UFR) subsequent to injecting a predetermined amount of saline to an injection location within the venous connection for a period of time; Means (10,100) for measuring arterial hematocrit at a second UFR that is different from the initial UFR; And And means (150) for multiplying the arterial hematocrit with the second UFR and dividing the result by the arterial hematocrit and subtracting the passage hematocrit therein to calculate the passage blood flow.