System and a method of determining a physiological parameter of a body comprising blood perfused tissue

A method of using a system for determining a physiological parameter of a body comprising blood perfused tissue, the method comprising:

• providing first information relating to an amount of blood in the blood perfused tissue from a photoplethysmography sensor (PPG sensor) of the system, based on the PPG sensor receiving first radiation from the blood perfused tissue, wherein the first radiation is radiation in a wavelength interval of 450 nm to 1000 nm,
• providing second information relating to a speed of blood in the blood perfused tissue from a laser Doppler velocimetry sensor (LDV sensor) of the system, the LDV including a source of coherent radiation, the providing of the second information based on the LDV sensor receiving second radiation from the blood perfused tissue, the LDV sensor receiving the second radiation based on the source emitting the coherent radiation to the blood perfused tissue, wherein the second radiation is radiation in a wavelength interval of 700 nm to 1000 nm, and
• determining, by a controller of the system, the physiological parameter by:
• calculating a prediction of a time derivative of the first information from both the second information and the first information, as an output of a model that predicts the time derivative of the first information relating to the amount of blood in the blood perfused tissue from both the first information relating to the amount of blood in the blood perfused tissue and the second information relating to the speed of blood in the blood perfused tissue;
• and
• determining the physiological parameter from the prediction of the time derivative of the first information, wherein the physiological parameter includes blood pressure;
• and
• causing, by the controller of the system, the physiological parameter to be output, illustrated, indicated, or any combination thereof.

A computer-readable medium storing a computer program comprising instructions which, when executed by a computing device or system, cause said computing device or system to execute a method, the method comprising:

• obtaining first information relating to an amount of blood in blood perfused tissue from a photoplethysmography sensor (PPG sensor), based on the PPG sensor receiving first radiation from the blood perfused tissue, wherein the first radiation is radiation in a wavelength interval of 450 nm to 1000 nm,
• obtaining second information relating to a speed of blood in the blood perfused tissue from a laser Doppler velocimetry sensor (LDV sensor), the LDV sensor including a source of coherent radiation, the second information obtained from the LDV sensor based on the LDV sensor receiving second radiation from the blood perfused tissue, the LDV sensor receiving the second information based on the source emitting the coherent radiation to the blood perfused tissue, wherein the second radiation is radiation in a wavelength interval of 700 nm to 1000 nm, and
• determining a physiological parameter by:
• calculating a prediction of a time derivative of the first information from both the second information and the first information, as an output of a model that predicts the time derivative of the first information relating to the amount of blood in the blood perfused tissue from both the first information relating to the amount of blood in the blood perfused tissue and the second information to the speed of blood in the blood perfused tissue;
• and
• determining the physiological parameter from the prediction of the time derivative of the first information;
• and
• causing the physiological parameter to be output, illustrated, indicated, or any combination thereof.