Detecting a vasoactive agent in the bloodstream

• US 9,968,304 B2
• Filed: 10/05/2012
• Issued: 05/15/2018
• Est. Priority Date: 10/07/2011
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Edwards Lifesciences Corporation
• Inventors: Jian, Zhongping, Hatib, Feras
• Primary Examiner(s): Jang, Christian
• Assistant Examiner(s): PREMRAJ, ANGELINE L
• Application Number:
  US14/350,332
• Publication Number:
  US 20140235971A1
• Time in Patent Office: 2,048 Days
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 8/488 involving Doppler signals

Abstract

A system and method are disclosed for detecting a vasoactive agent in patient'"'"'s bloodstream. In one embodiment, an input signal is received that is associated with arterial blood pressure. A change of an arterial blood pressure parameter over time is determined. A vasoactive agent is then automatically detected using the determined change. In another embodiment, a waveform associated with an arterial blood pressure signal can be received. A parameter associated with the received waveform is calculate. Then the calculated parameter can be used to determine the presence of a vasoactive agent. In yet another embodiment, detection of a vasoactive agent in any of the other embodiments can be used in a calculation of a hemodynamic parameter, such as cardiac output, stroke volume, systemic vascular resistance, stroke volume variation, cardiac index, stroke volume index, systemic vascular resistance index, vascular compliance, and vascular tone.

Claims

1. A method of using a patient monitoring system to detect a vasoactive agent in a bloodstream of a patient, the patient monitoring system including a blood pressure sensor, an analog-to-digital converter and a hardware processor configured to execute a software, the method comprising:

sensing, using the blood pressure sensor, a blood pressure of an artery of the patient and generating a blood pressure signal;

receiving, using the analog-to-digital converter, the blood pressure signal and converting the blood pressure signal to blood pressure data in digital form;

receiving, using the hardware processor executing the software, the blood pressure data for each of a plurality of time segments;

calculating, using the hardware processor executing the software, a first pressure parameter (FPP), a heart rate (HR), a second pressure parameter (SPP) and a ratio of the SPP to the FPP (SPP/FPP) for each of the plurality of time segments based on the blood pressure data;

determining, using the hardware processor executing the software, whether or not the bloodstream of the patient includes the vasoactive agent, wherein the bloodstream of the patient includes the vasoactive agent when the FPP increases over the plurality of time segments to exceed a FPP threshold, the HR is considered to remain unchanged over the plurality of time segments, and the SPP/FPP decreases over the plurality of time segments to fall below a SPP/FPP threshold;

obtaining a cardiac output of the patient;

wherein when the determining determines that the bloodstream of the patient includes the vasoactive agent, clinically treating the patient based on a determination that the cardiac output of the patient is inaccurate; and

wherein when the determining determines that the bloodstream of the patient does not include the vasoactive agent, clinically treating the patient based on the cardiac output of the patient being accurate.

2. The method of claim 1, wherein the blood pressure signal is a waveform, and wherein the method further comprises dividing the waveform into the plurality of time segments of a predetermined time.

3. The method of claim 1, wherein the sensing by the blood pressure sensor is performed non-invasively.

4. The method of claim 1, wherein the sensing by the blood pressure sensor is performed invasively.

5. The method of claim 1, wherein prior to the calculating, the method further comprises detecting beats in each of the plurality of time segments, and wherein the calculating calculates the FPP, the HR, the SPP and the SPP/FPP for each of the beats in each of the plurality of time segments.

6. The method of claim 1, wherein the FPP includes one or more of a diastolic pressure, a systolic pressure and a mean arterial pressure, and the SPP includes one or more of a standard deviation derived from the blood pressure data and a pulse pressure.

7. A method of using a patient monitoring system to detect a vasoactive agent in a bloodstream of a patient, the patient monitoring system including a presenting device, a blood pressure sensor, an analog-to-digital converter and a hardware processor configured to execute a software, the method comprising:

sensing, using the blood pressure sensor, a blood pressure of an artery of the patient and generate a blood pressure signal;

receiving, using the analog-to-digital converter, the blood pressure signal and converting the blood pressure signal to blood pressure data in digital form;

receiving, using the hardware processor executing the software, the blood pressure data for each of a plurality of time segments;

calculating, using the hardware processor executing the software, a mean arterial pressure (MAP), a heart rate (HR), a pulse pressure (PP) and a ratio of the PP to the MAP (PP/MAP) for each of the plurality of time segments based on the blood pressure data;

determining, using the hardware processor executing the software, whether or not the bloodstream of the patient includes the vasoactive agent, wherein the bloodstream of the patient includes the vasoactive agent when the MAP increases over the plurality of time segments to exceed a MAP threshold, the HR is considered to remain unchanged over the plurality of time segments, and the PP/MAP decreases over the plurality of time segments to fall below a PP/MAP threshold; and

obtaining, using the hardware processor executing the software, a hemodynamic parameter, using the blood pressure data, by taking into account whether or not that the bloodstream of the patient includes the vasoactive agent; and

clinically treating the patient using the hemodynamic parameter.

8. The method of claim 7, wherein the blood pressure signal is a waveform, and wherein the waveform is divided into the plurality of time segments of a predetermined time.

9. The method of claim 7, wherein the blood pressure sensor senses the blood pressure of the artery of the patient non-invasively.

10. The method of claim 7, wherein the blood pressure sensor senses the blood pressure of the artery of the patient invasively.

11. The method of claim 7, wherein prior to the calculating, the method further comprises detecting beats in each of the plurality of time segments, and wherein the calculating calculates the MAP, the HR, the PP and the PP/MAP for each of the beats in each of the plurality of time segments.

12. The method of claim 7, wherein when the determining determines that the bloodstream of the patient includes the vasoactive agent, clinically treating the patient based on the hemodynamic parameter being inaccurate, and wherein when the determining determines that the bloodstream of the patient does not include the vasoactive agent, clinically treating the patient based on the hemodynamic parameter being accurate.