Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
  • A61M1/36—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
  • A61M1/3621—Extra-corporeal blood circuits
  • A61M1/3653—Interfaces between patient blood circulation and extra-corporal blood circuit
  • A61M1/3656—Monitoring patency or flow at connection sites; Detecting disconnections
  • A61M1/3658—Indicating the amount of purified blood recirculating in the fistula or shunt
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
  • A61M1/36—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
  • A61M1/3621—Extra-corporeal blood circuits
  • A61M1/3623—Means for actively controlling temperature of blood
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2205/00—General characteristics of the apparatus
  • A61M2205/33—Controlling, regulating or measuring
  • A61M2205/3331—Pressure; Flow
  • A61M2205/3334—Measuring or controlling the flow rate
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2205/00—General characteristics of the apparatus
  • A61M2205/33—Controlling, regulating or measuring
  • A61M2205/3379—Masses, volumes, levels of fluids in reservoirs, flow rates
  • A61M2205/3382—Upper level detectors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2205/00—General characteristics of the apparatus
  • A61M2205/33—Controlling, regulating or measuring
  • A61M2205/3379—Masses, volumes, levels of fluids in reservoirs, flow rates
  • A61M2205/3386—Low level detectors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2230/00—Measuring parameters of the user
  • A61M2230/30—Blood pressure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2230/00—Measuring parameters of the user
  • A61M2230/50—Temperature

Definitions

• the invention relates to a blood treatment device with an extracorporeal blood circuit comprising an arterial line, a blood pump, a blood treatment unit and a venous line, wherein the arterial and venous line can be connected to a blood vessel of a patient and wherein the blood treatment device an evaluation and control unit for Determining the blood flow in the claimed vessel of the patient has.
• an arteriovenous fistula is often artificially produced for extracorporeal blood treatment, usually in the forearm between the Arteria Radialis and the Vena Cephalica.
• This short circuit of the artery and vein increases the vascular pressure, which is due to reduced tissue resistance.
• a high blood flow is achieved in the claimed vessel.
• various methods are recommended in relevant guidelines.
• An object of the invention is to provide a device for extracorporeal blood treatment, which allows a simple and reliable measurement of the blood flow in the vascular access.
• the invention relates to a blood treatment device with an extracorporeal blood circulation comprising an arterial line, a blood pump, a blood treatment unit and a venous line, wherein the arterial and venous line can be connected to a blood vessel of a patient and wherein the blood treatment device has an evaluation and control unit.
• the blood treatment device is characterized in that the evaluation and control unit is designed to carry out the following steps: (a1) determination of the blood recirculation in a blood vessel of the patient connected to the extracorporeal blood circulation; and (b) calculating the blood flow in the blood vessel using (a1) determined blood recirculation and a provided or also previously determined value for the cardiac output of the patient.
• the blood treatment device may be, for example, a dialysis machine or an apheresis machine.
• the blood treatment unit may be, for example, a dialyzer or a plasma filter.
• the blood treatment device further comprises a blood pressure sensor and the evaluation and control unit is designed to further perform the following step before step (b): (a2) Determining the cardiac output of the patient by evaluating the time course of a pressure pulse measured using the blood pressure sensor ,
• the blood pressure sensor may be adapted to measure blood pressure directly on the patient, such as the patient's arm or wrist. Suitable pressure sensors include piezoelectric pressure sensors.
• the cardiac output (cardiac output) is determined from oscillometric blood pressure measurements.
• the evaluation of such oscillometric blood pressure measurements is known, for example, for determining the blood pressure (see DE 10 2012 007 081 A1).
• Pulse-based methods for determining cardiac output are known in the art. All of these methods use pulse curves to determine cardiac output.
• the evaluation and control unit of the blood treatment device according to the invention can be designed to determine the cardiac output by means of such a pulse analysis based method and then to use in step (b).
• Suitable pulse analysis-based methods include the impulse response method, which is described in more detail, for example, in US 2011/0034813 A1, or the model flow method, which is described in more detail in EP 0 569 506 B1.
• the determination of cardiac output from the mean arterial blood pressure, the central venous pressure and the peripheral resistance as used for example in the commercially available device "Vicorder" Fa. SMT medical GmbH.
• the blood treatment device further comprises a bolus sensor disposed in the arterial line of the extracorporeal blood circuit, and the evaluation and control unit is configured to perform step (a1) in the following manner: (a1) determining blood recirculation in FIG a blood vessel of the patient connected to the extracorporeal blood circuit using the signal of the bolus sensor.
• the blood treatment device has a control unit and an actuator, wherein the actuator is designed so that a bolus can be provided downstream of a blood pump arranged in the extracorporeal blood circulation and / or the blood treatment unit, and wherein the control unit is designed such that, using the Actor during a measurement interval one or more times a bolus delivery takes place.
• the actuator may be, for example, a heater with which a temperature bolus can be generated.
• the actuator may be a metering system opening into the extracorporeal blood circulation, with which a concentrate bolus or temperature bolus can be produced.
• the blood treatment device further comprises a bolus sensor disposed in the venous line of the extracorporeal blood circuit, wherein the evaluation and control unit is configured to determine the blood recirculation in the vessel portion of the patient using the signals of the arterial and venous bolus sensor ,
• the evaluation and control unit here the similarity of the waveforms and the taken into account temporal offset of the signals received from the different sensors.
• the bolus sensor (s) may be temperature sensors to detect a temperature bolus.
• thermodilution The measurement of recirculation between the venous and arterial needle by means of thermodilution is described, for example, in Schneditz el al (2003), "Surveillance of Access Function by the Blood Temperature Monitor", Seminars in Dialysis 16, pp.
• the evaluation and control unit is designed to take into account, in addition to the blood recirculation and the cardiac output, the extracorporeal blood flow and the outflow of fluid in the blood treatment device when determining the blood flow in step (b).
• the extracorporeal blood flow Q b can be adjusted, for example, by adjusting the delivery rate of a blood pump present in the arterial line.
• the outflow of liquid in the blood treatment device may in particular be the ultrafiltration rate. This can be adjusted for example by means of a UF pump, which is arranged in a likewise connected to the dialyzer dialysis fluid.
• the evaluation and control unit is designed to assume critical values for the recirculation for a normal and / or inverse connection of the arterial and venous line on the assumption that the blood flow in the affected vessel can reach at most a certain proportion of the cardiac output
• the maximum proportion of the cardiac output which can reach the maximum blood flow in the affected vessel, may be, for example, 50%.
• critical values for recirculation at normal and inverse needle position can be defined. The critical values differ depending on the flow in the extracorporeal blood circulation.
• the evaluation and control unit is designed to compare the determined recirculation with these critical values and to group them based on the comparison.
• the device also has an output unit which is connected to the evaluation and control unit, wherein the output unit and the evaluation and control unit are designed to output a different signal to the user depending on the group membership of the determined recirculation.
• the output unit may, for example, output audible and / or visual signals to the user.
• three groups are distinguished: (1) the determined recirculation is below the critical value for normal connection; (2) the detected recirculation is above the critical value for normal port but below the critical value for inverse port; and (3) the determined recirculation is above the critical value for inverse port.
• a signal indicating a correct connection of the extracorporeal blood circulation to the vessel is output and / or if the determined recirculation of the group (3 ) can be assigned a signal indicative of an exchange of arterial and venous connections.
• the evaluation and control unit is designed so that when the determined recirculation of the group (2) has been assigned, the delivery rate of the blood pump is reduced and the implementation of steps (a1) and (b) is repeated.
• the evaluation and control unit is designed to output a warning signal if the determined blood flow in the affected vessel exceeds an upper threshold value or falls below a lower threshold value.
• the lower threshold may be 300 or 500 ml / min and the upper threshold may be 2000 or 1500 ml / min.
• the evaluation and control unit may preferably initiate the necessary procedures for data collection in the dialysis machine (e.g., operation of the blood pump at a certain rate or administration of a temperature bolus). It may be designed to automatically use the data or conclusions obtained (e.g., blood flow in the affected vessel, correct or inverse connection of the needles, correct access signals, etc.) to control the device.
• data or conclusions obtained e.g., blood flow in the affected vessel, correct or inverse connection of the needles, correct access signals, etc.
• the blood treatment device has an acoustic and / or visual output unit with which the data or conclusions (see above) determined by the evaluation and control unit are output to a user.
• the invention comprises a method for determining the blood flow in a blood vessel of a patient connected to the extracorporeal blood circulation of a preferably inventive blood treatment device. It is provided to determine the recirculation in the vessel and to determine the blood flow in the affected blood vessel of the patient on the basis of this recirculation and a likewise determined or otherwise estimated value for the cardiac output.
• the invention relates to a blood treatment device with an extracorporeal blood circuit comprising an arterial line, a blood pump, a blood treatment unit and a venous line, wherein the arterial and venous line can be connected to a blood vessel of a patient and wherein the blood treatment device has an evaluation and control unit.
• the evaluation and control unit is designed to determine the blood recirculation in a blood vessel of the patient connected to the extracorporeal blood circulation and to compare the ascertained recirculation with likewise determined or predetermined critical values and on the basis of the comparison group.
• a grouping of the recirculation values thus takes place optionally without ascertaining the blood flow in the blood vessel.
• the determination of the blood recirculation can be carried out as described above.
• the device may further comprise an output unit, which is in communication with the evaluation and control unit, wherein the output unit and the evaluation and control unit are designed to depending on the group affiliation the detected recirculation to issue a different signal to the user.
• the output can be carried out as described above.
• a response of the blood treatment device may be initiated.
• three groups can also be distinguished here: (1) the determined recirculation lies below the critical value for normal connection; (2) the detected recirculation is above the critical value for normal port but below the critical value for inverse port; and (3) the determined recirculation is above the critical value for inverse port.
• the evaluation and control unit can be designed so that when the determined recirculation of the group (2) has been assigned, the delivery rate of the blood pump is reduced and the determination of the blood recirculation is repeated.
• the invention comprises a method for determining the quality of the vascular access in a blood vessel of a patient connected to the extracorporeal blood circulation of a blood treatment device according to the invention. It is intended to determine the recirculation in the vessel, to compare the determined recirculation with likewise determined or predetermined critical values and to group them on the basis of the comparison.
• FIG. 1 shows a schematic representation of an embodiment of a dialysis machine according to the invention
• FIG. 2 shows a plot of critical values determined according to the invention for the proportion of recirculations R n and R x in normal or inverse needle position as a function of the cardiac output CO for extracorporeal blood flows of 200, 300 and 400 ml / min;
• FIG. 3 a plot of the relative error in the case of the invention
• FIG. 5 a plot of the relative error in the determination of the
• Cardiopulmonary recirculation in hemodialysis patients with cardiac output CO treated via vascular access with a shunt flow Q a is defined as
• Q a can be calculated if only one of the variables R n or R x is known.
• the error of determining Q a from CO and R n can be estimated as follows.
• CO (MAP-CVP) / R P
• MAP the mean arterial blood pressure
• CVP the central venous pressure
• R p the peripheral resistance.
• the central venous pressure can be measured or estimated using a central venous catheter and entered manually, for example Resistance can be determined from the falling edge of a pulse curve.
• FIG. 1 A schematic representation of an embodiment of a dialysis machine according to the invention is shown in FIG.
• the dialysis machine is generally identified by the reference numeral 1 in the figure. It has an extracorporeal blood circulation 2, which in a known manner comprises an arterial line 3 with a blood pump 4, a dialyzer 5 and a venous line 6.
• the arterial line 3 and the venous line 6 are connected to a vessel 9 of a patient 10 by means of an arterial needle 7 or a venous needle 8.
• a semipermeable membrane 11 is arranged, which separates the blood chamber 12 from the dialysis fluid chamber 13 within the dialyzer 5.
• a dialysis fluid system 14 is connected to the dialysis fluid chamber 13 and comprises a device 15 for the treatment of dialysis fluid, a supply line 16 to the dialyzer 5 and a discharge line 17 from the dialyzer 5.
• an ultrafiltration pump not shown in the figure can be arranged.
• the flow directions of the blood in the extracorporeal blood circulation 2 and the dialysis fluid in the dialysis fluid system 14 are shown in the figure by arrows.
• the dialysis machine 1 comprises an evaluation and control unit 18 and an output unit 19.
• temperature sensors 20 and 21 are arranged near the respective needles.
• the device 1 further comprises means, not shown in the figure, for changing the blood temperature in the venous blood line.
• These means can be, for example, that the temperature of the dialysis fluid generated in the device 15 are varied according to the specification of the evaluation and control unit 18 with the aim of changing the blood temperature.
• the change in blood temperature can also be effected, for example, by Peltier elements attached to the blood tubing system.
• the device 1 comprises a sensor 22 for measuring a pulse pressure curve of the patient which is suitable for determining CO, for example by a cuff on the upper arm. The sensor is connected to the evaluation and control unit 18 in a manner not shown in the figure.
• the blood pump 4 draws blood via the arterial needle 7 from the vessel 9 of the patient 10 into the arterial line 3 of the extracorporeal blood circuit 2 and then pumps the blood back through the dialyzer 5, the venous line 6 and the venous needle 8
• the temporal temperature profile of the withdrawn and returned blood is measured at the sensors 20 and 21 and the measured values are transmitted to the evaluation and control unit 18.
• the recirculation R is then determined in the evaluation and control unit 18 as described in Schneditz (2003).
• the heart time volume is determined by means of oscillometric blood pressure measurements on the blood pressure sensor.
• the calculations described above for determining the blood flow in the vessel 9 of the patient 10 are now carried out in the evaluation and control unit 18.
• the results can be output, for example, at the output unit 19, transmitted via any type of communication such as via network and / or automatically used for the control of the device 1. I Interpretation and use of the results:
• FIG. 2 shows the critical values calculated according to formula 9 for R n and R x as a function of cardiac output CO for extracorporeal blood flows of 200, 300 and 400 ml / min.
• FIG. 3 shows the relative error calculated in Formula 6 in the determination of Q a at a blood flow of 300 ml / min assuming a recirculation measurement error of ⁇ 1% and the determination of CO and Q b of ⁇ 10% for values of Q a from 400 to 2000 ml / min. From this it is clear that at low Q a the measurement accuracy is severely limited. Nevertheless, it is ensured that in any case Q a > Q b . Since the relative error for high Shunt flows decreases, the determination of Q a can be used to detect dangerously high shunt fluxes. Shunt flows> 2000 ml / min strain the heart of the patient resulting in increased mortality.
• a high shunt flow warning may be generated. If too low a shunt flow of ⁇ 600 ml / min or too high a shunt flow is detected with the described method, the user may be asked to exchange the needles for a more accurate determination of the shunt flow, which is then advantageously easily possible if already Disposable is available for this. From the determination of R x , Q a can then be determined more accurately according to formula 3, the determination of R n and CO would then serve only as prescreening.
• R> Rx crit the vascular recirculation is so high that there is a high probability of an exchange of arterial and venous needle. Again, the user can be informed by the output unit 19 in any way.
• FIG. 4 shows a plot of the shunt flux Q a as a function of CO at various values of R x according to formula 5 with an extracorporeal blood flow of 300 ml / min. It can be seen that, especially at low shunt flows ( ⁇ 800 ml / min), the shunt flow can be determined solely from the measured recirculation R x in the case of exchanged needles and that the value of the CO only slightly influences the value of the shunt flow if Q a ⁇ % CO is. This can also be seen in Figure 5, where the relative error in the determination of Q a formula 7 was applied at an extracorporeal blood flow of 300 ml / min.
• the shunt flow can be determined solely by measuring the recirculation of exchanged needles can be determined without requiring recirculation measurement in normal needle orientation.
• the needle exchange generally has to be done manually by the user using a corresponding disposable.
• the shunt flow can be immediately indicated by means of formula 5.
• the present invention provides a way of detecting a particularly excessively high shunt flow at hand.
• a very high shunt flow is medically undesirable.
• the recirculation and, for example, based on an oscillometric blood pressure measurement, the cardiac output is determined, for example, by administering a temperature bolus. From both, the shunt flow is calculated using formula 4. This can be determined, especially at very high rivers with relatively little error.
• the invention allows the determination of two limit values of the recirculation and the derivation of corresponding conclusions. Another aspect of the invention is particularly concerned with the comparison of recirculation with limits and the derivation of conclusions, regardless of how the limits are determined.

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• Health & Medical Sciences (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Biomedical Technology (AREA)
• Engineering & Computer Science (AREA)
• Anesthesiology (AREA)
• Cardiology (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• External Artificial Organs (AREA)
• Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)

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• 2016
  • 2016-02-15 DE DE102016001710.4A patent/DE102016001710B4/de active Active
• 2017
  • 2017-02-15 EP EP17705314.7A patent/EP3416701B1/de active Active
  • 2017-02-15 WO PCT/EP2017/000214 patent/WO2017140424A2/de not_active Ceased
  • 2017-02-15 US US15/998,566 patent/US11529450B2/en active Active
  • 2017-02-15 CN CN201780011559.6A patent/CN108697841B/zh active Active
  • 2017-02-15 JP JP2018561302A patent/JP7082577B2/ja active Active

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