Method And System For Determining Vascular Changes Using Plethysmographic Signals
Embodiments of the present disclosure relate to determining changes in a vasculature by analyzing changes in one or more attributes of a plethysmographic signal. According to certain embodiments, an apparatus may obtain plethysmographic signals prior to and subsequent to the administration of a vasoactive stimulus. The apparatus may include a processing unit configured to analyze and to compare attributes of the plethysmographic signals. The processing unit may correlate any changes in signal attributes to a change in a physiological condition of the vasculature (e.g., vascular tone/compliance). The apparatus may also include a display unit configured to present any changes in the vasculature as well as any alarms in response to a trigger from the processing unit.
1 . A monitor comprising:
a processing unit configured to:
calculate one or more baseline attributes of a baseline plethysmographic signal obtained from a patient;
compare one or more calculated attributes of a plethysmographic signal to the one or more calculated baseline attributes; and
correlate changes in the one or more calculated attributes from the one or more calculated baseline attributes to a change in vascular compliance; and
a display unit configured to provide an indication of the change in vascular compliance.
2 . The monitor of claim 1 , wherein the baseline plethysmographic signal or the baseline attributes are obtained from a memory of a sensor.
3 . The monitor of claim 1 , wherein the baseline plethysmographic signal and the plethysmographic signal comprise continuous wavelet transformed signals.
4 . The monitor of claim 1 , wherein the attributes of the baseline plethysmographic signal and the plethysmographic signal comprise one or more amplitudes of one or more peaks, a length in duration from a beginning of a systolic phase to an end of a diastolic phase, an area under a curve, a position of a dicrotic notch, slopes of ascending and descending limbs, or movement of the dicrotic notch.
5 . The monitor of claim 1 , wherein the processing unit is configured to trigger an alarm when the change in vascular compliance exceeds a certain threshold.
6 . The monitor of claim 5 , wherein the threshold comprises a percent change in the vascular compliance.
7 . The monitor of claim 5 , wherein the display unit is configured to present the alarm in response to the trigger from the processing unit.
8 . The monitor of claim 1 , wherein the plethysmographic signal is obtained from the patient after the administration of a vasoactive stimulus.
9 . A system comprising:
a sensor capable of generating a physiological signal;
a processing unit configured to:
calculate one or more baseline attributes of a baseline physiological signal obtained from a patient;
compare one or more calculated attributes of a subsequent physiological signal obtained from the patient to the one or more calculated baseline attributes; and
correlate changes in the one or more calculated attributes from the one or more calculated baseline attributes to a change in vascular compliance.
10 . The system of claim 9 , wherein the baseline physiological signal and the subsequent physiological signal comprise continuous wavelet transformed signals.
11 . The system of claim 9 , wherein the attributes of the baseline physiological signal and the subsequent physiological signal comprise one or more amplitudes of one or more peaks, a length in duration from a beginning of a systolic phase to an end of a diastolic phase, an area under a curve, a position of a dicrotic notch, slopes of ascending and descending limbs, or movement of the dicrotic notch.
12 . The system of claim 9 , wherein the processing unit is configured to obtain the baseline physiological signal or the baseline attributes from a memory of the sensor.
13 . The system of claim 9 , comprising a display unit configured to provide an indication of the change in vascular compliance.
14 . The system of claim 9 , wherein the processing unit is configured to trigger an alarm when the change in vascular compliance exceeds a certain threshold.
15 . The system of claim 14 , comprising a display unit configured to present the alarm in response to the trigger from the processing unit.
16 . The system of claim 14 , wherein the threshold comprises a percent change in the vascular compliance.
17 . The system of claim 9 , wherein the subsequent physiological signal is obtained from the patient after the administration of a vasoactive stimulus.
18 . A method, comprising:
obtaining a baseline plethysmographic signal from a patient;
calculating one or more attributes of the baseline plethysmographic signal;
administering a vasoactive stimulus to the patient;
obtaining a subsequent plethysmographic signal from the patient;
calculating one or more attributes of the subsequent plethysmographic signal;
comparing the one or more calculated attributes of the subsequent plethysmographic signal to the one or more calculated attributes of the baseline plethysmographic signal; and
correlating changes in the one or more calculated attributes to a change in vascular compliance in the patient.
19 . The method of claim 18 , comprising providing an indication of change in the vascular compliance on a display.
20 . The method of claim 18 , comprising triggering an alarm when the change in vascular compliance exceeds a certain threshold.