Cerebral hemodynamic monitoring system

• US 5,676,145 A
• Filed: 08/21/1995
• Issued: 10/14/1997
• Est. Priority Date: 08/21/1995
• Status: Expired due to Fees

• Current Assignee: University of Maryland
• Original Assignee: University of Maryland
• Inventors: Bar-Lavie, Yaron P.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): CARTER, RYAN CHRISTOPHER
• Application Number:
  US08/517,356
• Time in Patent Office: 785 Days
• Field of Search: 128/634, 128/664-665, 128/691-692, 128/670, 128/642, 128/736, 604/53, 606/41
• US Class Current: 600/342
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/028 by thermo-dilution
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence

Abstract

A cerebral hemodynamics monitoring device includes a catheter having an optic fiber 20 for measurement of oxygen saturation, a first thermistor 30 positioned not more than about 25 mm from the tip of the catheter, and a second thermistor 32, located preferably at an entry to the catheter. The catheter is insertable in a vein over a guide wire using the Seldinger technique. The monitoring device also includes a computerized cerebral hemodynamics monitor that performs continuous jugular oximetry (S_j O₂, %), arterial pulse oximetry (S_a O₂, %), and measurement of jugular blood flow (JBF, ml/min/100 g tissue), preferably via retrograde thermodilution based on data collected in the catheter devices. Based on these measurements, the monitoring device performs continuous calculation of cerebral O₂ extraction (CEO₂, %), cerebral O₂ consumption (CMRO₂), cerebral blood flow (CBF), and cerebral vascular resistance (CVR). The device system also includes a programmable injectate infusion pump connected to the catheter that provides for background flow, planned interval boluses, and PRN bolus capability. The monitoring system also includes output devices for displaying data and for communicating data to other external devices.

Claims

1. A cerebral hemodynamic monitoring system comprising:

a jugular catheter provided with means for measuring jugular blood flow and means for measuring blood oxygen saturation;

an independently regulatable infusion pump connected to an entry of the jugular catheter; and

a computer data analysis and storage system connected to receive data from said means for measuring jugular blood flow and said means for measuring blood oxygen saturation for calculating cerebral O₂ extraction (CEO₂, %), cerebral O₂ consumption (CMRO₂), cerebral blood flow (CBF), and cerebral vascular resistance (CVR).

2. The cerebral hemodynamic monitoring system of claim 1, wherein the jugular catheter has a length sufficient to reach the jugular bulb in an adult.

3. The cerebral hemodynamic monitoring system of claim 2, wherein the jugular catheter has a length in a range of 18-20 cm long.

4. The cerebral hemodynamic monitoring system of claim 1, wherein the jugular catheter has an outer diameter less than an inner diameter of an adult vein to permit blood flow past the catheter.

5. The cerebral hemodynamic monitoring system of claim 4, wherein the jugular catheter has an outer diameter of 4.5-5.5 Fr, and an inner diameter of 4-5 Fr.

6. The cerebral hemodynamic monitoring system of claim 1, wherein the jugular catheter is 18 cm long, has an outer diameter of 4.5 Fr, and an inner diameter of 4 Fr.

7. The cerebral hemodynamic monitoring system of claim 1, wherein the jugular catheter is composed of a substance which is substantially rigid at room temperature and during insertion, and pliant at body temperature.

8. The cerebral hemodynamic monitoring system of claim 1, wherein the jugular catheter is opaque to X-rays, and is marked at the tip for easy visualization using conventional X-ray equipment.

9. The cerebral hemodynamic monitoring system of claim 1, wherein the means for measuring oxygen saturation comprises an optic fiber for measuring oxygen saturation.

10. The cerebral hemodynamic monitoring system of claim 9, wherein the optic fiber is capable of transmitting at least two wavelengths of light.

11. The cerebral hemodynamic monitoring system of claim 1, wherein said means for measuring jugular blood flow comprises a first thermistor located not more than 25 mm from a tip of the catheter, and a second thermistor located at an entry to the catheter.

12. The cerebral hemodynamic monitoring system of claim 11, wherein the first thermistor is located 25 mm from the tip of the catheter.

13. The cerebral hemodynamic monitoring system of claim 1, wherein the jugular catheter is insertable over a guide wire.

14. The cerebral hemodynamic monitoring system of claim 1, further comprising a guide wire having a length greater than a length of the catheter and disposed within an inner lumen of the catheter.

15. The cerebral hemodynamic monitoring system of claim 14, wherein the guide wire has a soft tip, and has a length in a range of 40-45 cm and a diameter less than 0.025".

16. The cerebral hemodynamic monitoring system of claim 14, wherein the guide wire is 40 cm long.

17. The cerebral hemodynamic monitoring system of claim 1, wherein the computer data analysis and storage system comprises:

a computer for analyzing data received from said means for measuring oxygen saturation and said means for measuring blood flow;

means for displaying raw and processed data;

means for printing raw and processed data; and

means for storing raw and processed data.

18. A cerebral hemodynamic monitoring system comprising:

a jugular catheter;

means for measuring jugular blood flow attached to the jugular catheter;

means for measuring blood oxygen saturation attached to the jugular catheter;

an independently regulatable infusion pump connected to an entry of the jugular catheter; and

a computer data analysis and storage system connected to receive data from said means for measuring blood flow and said means for measuring oxygen saturation and calculating cerebral O₂ extraction (CEO₂, %), cerebral O₂ consumption (CMRO₂), cerebral blood flow (CBF), and cerebral vascular resistance (CVR), wherein said means for measuring jugular blood flow is a retrograde thermodilution device.

19. A method for monitoring cerebral hemodynamics with a system a jugular catheter comprising means for measuring blood flow and means for measuring oxygen saturation, an independently regulatable infusion pump connectable to the jugular catheter, and a computer data analysis and storage system connected to receive blood flow and oxygen extraction data from the jugular catheter, the method comprising the steps of:

a) inserting the jugular catheter in a patient;

b) introducing an infusion liquid in the catheter;

c) collecting data on blood flow and oxygen saturation with the catheter;

d) analyzing said data with the computer data analysis system to obtain cerebral O₂ extraction (CEO₂, %), cerebral O₂ consumption (CMRO₂), cerebral blood flow (CBF), and cerebral vascular resistance (CVR);

e) providing analyzed data in a comprehensible form; and

f) repeating steps b through e as needed.

20. The method according to claim 19, further comprising the step of storing the analyzed data obtained in step d, and wherein the step of providing analyzed data includes retrieving and providing previously stored data.

22. The method according to claim 19, wherein said step of repeating steps "b" through "e" as needed is performed at a rate of at least ten times per hour.

21. A jugular catheter usable in a cerebral hemodynamic monitoring system, said catheter comprising:

a catheter shaft including at least one through lumen;

at least one sensor attached to said catheter shaft for obtaining data that permits measurement of jugular blood flow;

at least one sensor attached to said catheter shaft for obtaining data that permits measurement of blood oxygen saturation;

wherein said catheter shaft is sized and configured to permit fluid to be injected at a frequency of at least ten times per hour through said at least one through lumen into a patient'"'"'s jugular vein in which said catheter shaft has been inserted for a continuous and prolonged time.