Blood volume determination and sensor calibration
AssigneeTransonic Systems, Inc.
InventorsNikolai M. Krivitski, Dimitry M. Starostin
Life of this patent
Estimating the term…
Abstract
An apparatus is provided for determining a calibration coefficient of a blood property sensor located in a blood system, wherein the blood system can include a vascular portion and an extracorporeal portion. The blood property sensor can be located in the extracorporeal portion to measure the change in a blood property corresponding to the passing of an indicator. The indicator can include a known amount of an introduced dilution indicator. The controller is provided for determining the calibration coefficient of the blood property sensor corresponding to the introduced dilution indicator in the measured change in the blood property.
Claims17
A method for calibrating a blood property sensor, the method comprising:
- (a) connecting an arterial tubing portion of a dialysis system to withdraw blood from a patient and connecting a venous tubing portion of the dialysis system to deliver blood to the patient;
- (b) passing diluted blood having a dilution indicator past the blood property sensor in the venous tubing portion;
- (c) determining at least one property of the diluted blood passing the blood property sensor in the venous tubing portion;
- and
- (d) determining a calibration coefficient K of the blood property sensor based on the determined blood property of the diluted blood passing the blood property sensor in the venous tubing portion and the relationship
- K
- =
- -
- V
- Inj
- V
- +
- V
- Inj
- *
- Δ
-
-
- U
- Inj
- where Vinj is a volume of the dilution indicator;
- V=(QB−QUF)*ΔTinj where QB is a blood flow rate in the arterial tubing portion. QUF is an ultrafiltration rate of the dialysis system, ΔTinj is the transit time of the dilution indicator;
- and ΔUinj relates to the determined blood property and is integrated over ΔTinj.
A method for calibrating a blood property sensor in a blood system having a vascular portion and an extracorporeal portion, the method comprising:
- (a) introducing an indicator bolus upstream of a blood property sensor in the extracorporeal portion to form diluted blood;
- (b) measuring a property of the diluted blood with the blood property sensor in the extracorporeal portion;
- and
- (c) determining a calibration coefficient K of the blood property sensor based on the measured property of the diluted blood and the relationship
- K
- =
- -
- V
- Inj
- V
- +
- V
- Inj
- *
- Δ
-
-
- U
- Inj
- where Vinj is a volume of the indicator bolus;
- V=(QB−QUF)*ΔTinj where QB is a blood flow rate in the extracorporeal portion, QUF is an ultrafiltration rate of a dialysis system, ΔTinj is the transit time of the indicator bolus;
- and ΔUinj relates to the measured property of the diluted blood and is integrated over ΔTinj.
An apparatus for calibrating a blood property sensor in a blood system, comprising:
- (a) an extracorporeal portion having a first end adapted to be connected to a vascular portion of the blood system at an upstream end and a second end adapted to be connected to the vascular portion at a downstream end;
- (b) a blood property sensor coupled to the extracorporeal portion for detecting a property of diluted blood flowing within the extracorporeal portion;
- and
- (c) means for determining a calibration coefficient K of the blood property sensor based on the detected property of the diluted blood and the relationship
- K
- =
- -
- V
- Inj
- V
- +
- V
- Inj
- *
- Δ
-
-
- U
- Inj
- where Vinj is a volume of a dilution indicator forming the diluted blood;
- V=(QB−QUF)*ΔTinj where QB is a blood flow rate in the extracorporeal portion, QUF is an ultrafiltration rate of a dialysis system connected to the extracorporeal portion, ΔTinj is the transit time of the diluted blood:
- and ΔUinj relates to the detected property of the diluted blood and is integrated over ΔTinj.
An apparatus for calibrating a blood property sensor in a blood system having an extracorporeal portion, comprising:
- (a) a blood property sensor coupled to the extracorporeal portion for detecting a property of diluted blood flowing within the extracorporeal portion;
- and
- (b) means connected to the blood property sensor for determining a calibration coefficient K of the blood property sensor based on the detected property of the diluted blood in the extracorporeal portion and the relationship
- K
- =
- -
- V
- Inj
- V
- +
- V
- Inj
- *
- Δ
-
-
- U
- Inj
- where Vinj is a volume of a dilution indicator forming the diluted blood;
- V=(QBQUF)*ΔTinj where QB is a blood flow rate in the extracorporeal portion, QUF is an ultrafiltration rate of a dialysis system connected to the extracorporeal portion, ΔTinj is the transit time of the diluted blood;
- and ΔUinj relates to the detected property of the diluted blood and is integrated over ΔTinj.
A method of calibrating a blood property sensor in an extracorporeal blood circuit fluidly connected to a vascular blood circuit, the method comprising:
- (a) introducing a change to a predetermined blood property;
- (b) measuring a corresponding change in the blood property at a blood property sensor in the extracorporeal blood circuit;
- and
- (c) determining a calibration coefficient K of the blood property sensor based on the measured change and the relationship
- K
- =
- -
- V
- Inj
- V
- +
- V
- Inj
- *
- Δ
-
-
- U
- Inj
- where Vinj is a volume of a dilution indicator introducing the change in the predetermined blood property;
- V=(QB−QUF)*ΔTinj where QB is a blood flow rate in the extracorporeal blood circuit, QUF is an ultrafiltration rate of a dialysis system connected to the extracorporeal blood circuit, ΔTinj is the transit time of the dilution indicator:
- and ΔUinj relates to the measured change and is integrated over ΔTinj.
A method of calibrating a blood property sensor in an extracorporeal blood circuit, the method comprising:
- (a) introducing a known amount of indicator into an extracorporeal blood circuit;
- (b) measuring a change in a blood parameter corresponding to passage of the indicator at a blood property sensor coupled to the extracorporeal blood circuit;
- and
- (c) determining a calibration coefficient K of the blood property sensor based on the measured change and the relationship
- K
- =
- -
- V
- Inj
- V
- +
- V
- Inj
- *
- Δ
-
-
- U
- Inj
- where Vinj is a volume of the introduced indicator;
- V=(QB−QUF)*ΔTinj where QB is a blood flow rate in the extracorporeal blood circuit, QUF is an ultrafiltration rate of a dialysis system connected to the extracorporeal blood circuit, ΔTinj is the transit time of the introduced indicator;
- and ΔUinj relates to the measured change and is integrated over ΔTinj.
A method of calibrating a blood property sensor in an extracorporeal blood circuit fluidly connected to a vascular blood circuit, the method comprising:
- (a) measuring a blood property of a dilution indicator bolus passing a blood property sensor in the extracorporeal blood circuit;
- and
- (b) determining the calibration coefficient K of the blood property sensor based on the measured blood property and the relationship
- K
- =
- -
- V
- Inj
- V
- +
- V
- Inj
- *
- Δ
-
-
- U
- Inj
- where Vinj is a volume of the dilution indicator;
- V=(QB−QUF)*ΔTinj where QB is a blood flow rate in the extracorporeal blood circuit, QUF is an ultrafiltration rate of a dialysis system connected to the extracorporeal blood circuit, ΔTinj is the transit time of the dilution indicator;
- and ΔUinj relates to the measured blood property and is integrated over ΔTinj.
Dependencies are inferred from the claim text.