Claims
- 1. 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 filtered blood to the patient; (b) passing a dilution indicator past the blood property sensor in the venous tubing portion; (c) determining at least one property of blood passing the blood property sensor; and (d) determining a calibration coefficient of the blood property sensor.
- 2. The method of claim 1, further comprising determining a blood volume change corresponding the calibration coefficient.
- 3. The method of claim 1, further comprising changing an ultrafiltration rate of the dialysis system to introduce a dilution indicator into the dialysis system.
- 4. The method of claim 1, further comprising employing an ultrasound sensor as the blood property sensor.
- 5. The method of claim 1, wherein determining at least one property of blood includes determining one of protein concentration, saline or electrolyte of the blood.
- 6. The method of claim 1, wherein determining at least one property of blood includes measuring one of a photometric, optical, electrical or thermal property of the blood.
- 7. The method of claim 1, wherein passing a dilution indicator past the blood property sensor includes passing a known volume of the dilution indicator past the blood property sensor.
- 8. A method for calibrating a 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; (b) measuring a property of diluted blood with the blood property sensor in the extracorporeal portion; and (c) determining a calibration coefficient of the blood property sensor corresponding to the measured property of the blood.
- 9. The method of claim 8, further comprising changing an ultrasound velocity in the blood upon introducing an indicator bolus.
- 10. The method of claim 8, wherein measuring a property of diluted blood includes measuring one of photometric, optical, electrical or thermal property of the blood.
- 11. The method of claim 8, wherein measuring a property of diluted blood includes measuring one of protein concentration, saline, ultrasound velocity or electrolyte of the blood.
- 12. 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 of the blood property sensor corresponding to the detected property of the diluted blood.
- 13. The apparatus of claim 12, wherein the blood property sensor is one of a photometric, optical, electrical or thermal sensor.
- 14. The apparatus of claim 12, wherein the extracorporeal portion includes an arterial length and the blood property sensor is located along the arterial length.
- 15. 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 of the blood property sensor corresponding to the detected property of the diluted blood in the extracorporeal portion.
- 16. 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 known 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 of the blood property sensor corresponding to the measured change.
- 17. 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 of the blood property sensor corresponding to the measured change.
- 18. 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 of the blood property sensor corresponding to the measured blood property.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Divisional of 10/314,817, filed Dec. 9, 2002, which is CIP of U.S. Ser. No. 09/528,880, now U.S. Pat. No. 6,493,567, issued Dec. 10, 2002, which is a Divisional of U.S. Ser. No. 08/950,244 filed Oct. 14, 1997, now U.S. Pat. No. 6,041,246, issued Mar. 21, 2000.
Divisions (2)
|
Number |
Date |
Country |
Parent |
10314817 |
Dec 2002 |
US |
Child |
10769834 |
Feb 2004 |
US |
Parent |
08950244 |
Oct 1997 |
US |
Child |
09528880 |
Mar 2000 |
US |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09528880 |
Mar 2000 |
US |
Child |
10314817 |
Dec 2002 |
US |