Non-invasive blood pressure monitor with improved performance

• US 20070106163A1
• Filed: 10/12/2005
• Published: 05/10/2007
• Est. Priority Date: 10/12/2005
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Kolluri, Sai, Friedman, Bruce, Hersh, Lawrence
• Granted Patent: US 7,678,059 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/02255 the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]

Abstract

A blood pressure measurement system that utilizes both a non-invasive blood pressure (NIBP) monitor having a blood pressure cuff and a continuous non-invasive blood pressure (CNIBP) monitor. During operation of the NIBP monitor, the blood pressure cuff is inflated to an initial inflation pressure greater than the systolic blood pressure for the patient being monitored. The CNIBP monitor calculates an estimated blood pressure that is supplied to the NIBP monitor. The NIBP monitor utilizes the continuous, estimated blood pressure to select a target inflation pressure for the blood pressure cuff. During operation of the NIBP monitor, the size of the pressure steps from the initial inflation pressure to a final pressure can be varied based upon the continuous blood pressure estimate from the NIBP monitor.

Claims

1. A method of monitoring blood pressure in a patient, the method comprising the steps of:

providing a continuous, non-invasive blood pressure (CNIBP) monitor operable to continuously estimate the blood pressure of the patient and generate a continuous blood pressure estimate;

calculating a target inflation pressure based upon the continuous blood pressure estimate from the CNIBP monitor;

positioning a blood pressure cuff on the patient;

inflating the blood pressure cuff to the target inflation pressure;

continuously decreasing the pressure in the blood pressure cuff while monitoring for oscillometric pulses in the blood pressure cuff; and

calculating the systolic pressure, mean arterial pressure and diastolic pressure based upon the oscillometric pulses detected during deflation of the blood pressure cuff.

2. The method of claim 1 wherein the CNIBP monitor continuously determines at least an estimated systolic blood pressure, wherein the target inflation pressure is selected above the estimated systolic blood pressure.

3. The method of claim 2 wherein the target inflation pressure is the estimated systolic blood pressure plus an offset value.

4. The method of claim 3 wherein the offset value is determined as a statistical function of the estimated systolic pressure over a pre-determined number of the previous beats

5. The method of claim 4 wherein the statistical function of the systolic pressure is the standard deviation

6. The method of claim 1 wherein the inflation pressure in the blood pressure cuff is decreased from the target inflation pressure to a final pressure through a series of pressure steps, wherein the oscillometric pulses are monitored at each pressure step, wherein each pressure step represents a decrease in the in the cuff pressure

7. The method of claim 6 further comprising the step of varying the size of the pressure steps based upon the continuous blood pressure estimate.

8. The method of claim 7 wherein the CNIBP monitor continuously determines at least an estimate systolic blood pressure, an estimated diastolic blood pressure and an estimate mean arterial pressure, wherein the size of the steps decreases near the mean arterial pressure estimated by the CNIBP monitor.

9. The method of claim 8 wherein the size of the steps are increased between the estimated mean arterial pressure and the estimated diastolic pressure.

10. A method of enhancing the operation of a non-invasive blood pressure (NIBP) monitor having a blood pressure cuff selectively inflatable and deflatable to determine at least a systolic pressure, a mean arterial pressure and a diastolic pressure for a patient, the method comprising the steps of:

providing a continuous non-invasive blood pressure (CNIBP) monitoring system operable to continuously estimate the blood pressure of the patient and generate a continuous blood pressure estimate;

calculating an initial target inflation pressure based upon the continuous blood pressure estimate;

inflating the blood pressure cuff to the target inflation pressure;

deflating the blood pressure cuff from the target inflation pressure to a final pressure;

monitoring for oscillometric pulses in the blood pressure cuff as the blood pressure cuff is deflated from the target inflation pressure to the final pressure; and

calculating and displaying the systolic pressure, mean arterial pressure and diastolic pressure based upon the oscillometric pulses.

11. The method of claim 10 wherein the CNIBP monitor continuously determines at least an estimated systolic blood pressure, wherein the target inflation pressure is selected above the estimated systolic blood pressure.

12. The method of claim 11 wherein the target inflation pressure is the estimated systolic blood pressure plus an offset value.

13. The method of claim 10 wherein the inflation pressure in the blood pressure cuff is decreased from the target inflation pressure to a final pressure through a series of pressure steps, wherein the oscillometric pulses are monitored at each pressure step, wherein each pressure step represents a decrease in the inflation pressure in the blood pressure cuff.

14. The method of claim 13 further comprising the step of varying the size of the pressure steps based upon the continuous blood pressure estimate.

15. The method of claim 14 wherein the CNIBP monitor continuously determines at least an estimate systolic blood pressure, an estimated diastolic blood pressure and an estimate mean arterial pressure, wherein the size of the steps decreases near the mean arterial pressure estimated by the CNIBP monitor.

16. The method of claim 15 wherein the size of the steps are increased between the estimated mean arterial pressure and the estimated diastolic pressure.

17. A system for monitoring blood pressure in a patient, the system comprising:

a central processor;

a non-invasive blood pressure monitor including a blood pressure cuff positionable on the patient, the blood pressure cuff being coupled to a supply of pressurized air such that the blood pressure cuff can be selectively inflated and deflated by the central processor;

a continuous non-invasive blood pressure (CNIBP) monitor positionable on the patient to continuously estimate the blood pressure of the patient and generate a continuous blood pressure estimate,

wherein the central processor controls the inflation and deflation of the blood pressure cuff based upon the continuous blood pressure estimates.

18. The system of claim 17 wherein the NIBP monitor includes a pressure transducer operable to detect the blood pressure of the patient, wherein the pressure transducer is coupled to the central processor.

19. The system of claim 18 wherein in the central processor is operable to inflate the blood pressure cuff to a target pressure and deflate the blood pressure cuff in a series of steps from the target pressure to determine the blood pressure of the patient, wherein the central processor estimates the target pressure based upon the continuous blood pressure estimates.

20. The system of claim 18 further comprising a display coupled to the central processor, wherein the central processor displays the detected blood pressure based on the information obtained from the pressure transducer.

21. The system of claim 19 wherein in the CNIBP monitor estimates at least the systolic blood pressure such that the target pressure is based upon the estimated systolic pressure.

22. The system of claim 19 wherein the central processor is operable to vary the size of each of the series of steps following the target pressure based upon the estimated blood pressure from the CNIBP monitor.