Integrated biosensing systems

An integrated sensing system for characterizing blood flow in a subject, the sensing system comprising:

• a light source assembly comprising a light source configured to emit light of a particular wavelength;
• and
• an integrated circuit electrically connected to the light source assembly, the integrated circuit comprising;
• a light detector assembly comprising multiple light detectors configured to detect light of the particular wavelength;
• a correlator configured to determining a delay between optical signals detected by respective light detectors of the light detector assembly.

A method for characterizing blood flow in a subject, the method comprising:

• illuminating a blood vessel of the subject with light from a light source assembly electrically connected an integrated circuit;
• detecting, by a first light detector of a light detector assembly of the integrated circuit, a first optical signal indicative of a blood flow event at a first location in the blood vessel;
• detecting, by a second light detector of the light detector assembly of the integrated circuit, a second optical signal indicative of a blood flow event at a second location in the blood vessel;
• based on (i) a time delay between the first optical signal and the second optical signal and (ii) a separation between the first light detector and the second light detector, determining a characteristic of blood flow in the subject.

A method for determining a physical characteristic of a subject, the method comprising:

• illuminating skin of the subject with light of multiple wavelengths from a light source assembly electrically connected to an integrated circuit;
• detecting, by a spectral sensor of the integrated circuit, a spectrum of light absorption by the skin;
• and
• determining a physical characteristic of the subject based on the detected spectrum of light absorption by the skin.