Systems and methods for monitoring blood pressure

A patient monitor configured to monitor blood pressure, comprising:

• a memory, comprising machine-readable instructions that, when executed by one or more processors, cause the one or more processors to:
• receive a plurality of plethysmography signals representative of one or more patient parameters;
• determine a change in a differential pulse transit time of the plurality of plethysmography signals over a period of time;
• determine a change in a pulse shape metric of a plethysmography signal of the plurality of plethysmography signals over the period of time;
• determine a confidence level based on whether there is an expected correlation between the change in the differential pulse transit time and the change in the pulse shape metric over the period of time, wherein the confidence level is determined to be a low confidence level based on a positive correlation between the change in the differential pulse transit time and the change in the pulse shape metric over the period of time;
• and
• in response to determining the confidence level is the low confidence level, switching from determining a blood pressure via a first monitoring mode to determining a blood pressure via a second monitoring mode different from the first monitoring mode.

A method, comprising:

• receiving, via a processor, a plurality of plethysmography signals representative of one or more patient parameters;
• generating, via the processor, a blood pressure measurement based on a differential pulse transit time of the plurality of plethysmography signals;
• determining, via the processor, a change in the differential pulse transit time over a period of time;
• determining, via the processor, a change in a pulse shape metric of a plethysmography signal of the plurality of plethysmography signals over the period of time;
• determining, via the processor, a low confidence level associated with the blood pressure measurement based on a positive correlation between the change in the differential pulse transit time and the change in the pulse shape metric over the period of time;
• and
• generating, via the processor, the blood pressure measurement based on the pulse shape metric of the plethysmography signal in response to determining the low confidence level.

A system for monitoring blood pressure comprising:

• a plurality of plethysmography sensors configured to obtain respective plethysmography signals;
• a patient monitor configured to:
• receive a plurality of plethysmography signals representative of one or more patient parameters;
• determine a change in a differential pulse transit time of the plurality of plethysmography signals over a period of time;
• determine a change in a pulse shape metric of a plethysmography signal of the plurality of plethysmography signals over the period of time;
• determine a high confidence level based on an inverse correlation between the change in the differential pulse transit time and the change in the pulse shape metric over the period of time;
• and
• generating a blood pressure measurement based on the differential pulse transit time in response to determining the high confidence level.