Optical sensor containing a waveguide with holographic elements for measuring a pulse and blood oxygen saturation

A spectrometry device for noninvasive measurement of at least one medical characteristic value on biological tissue, comprising:

• a carrier medium, formed as a light guide for transmitting coupled-in light by internal reflection, having a transceiver region and a measuring region arranged offset along a longitudinal extension direction of the carrier medium with respect to the transceiver region and provided for application of the biological tissue;
• a transceiver device having a detector and at least one first light source to emit first light having a first wavelength onto the transceiver region of the carrier medium,
• the transceiver region having a predefined transceiver deflector to couple at least the first light emitted by the first light source into the carrier medium towards the measuring region,
• the measuring region having a predefined measuring deflector configured to
• decouple the first light out of the carrier medium towards a measuring surface of the carrier medium in the measuring region, the biological tissue reflecting the first light back to the carrier medium when the biological tissue is applied to the measuring surface, and
• couple the first light reflected from the biological tissue back into the carrier medium towards the predefined transceiver deflector of the transceiver region where the first light is decoupled out of the carrier medium onto the detector of the transceiver device, and
• the detector configured to determine a first intensity signal of the first wavelength;
• and
• an evaluator configured to determine at least one of a pulse frequency signal and a pulse curve signal as a medical characteristic value based on a time curve of the first intensity signal,
• wherein
• the at least one optical grating is one of a surface holographic grating and a volume holographic grating having a multiplex diffraction structure for at least the first wavelength,
• the first wavelength is in a range from 600 nm to 800 nm,
• the transceiver device further comprises a second light source to emit second light having a second wavelength onto the transceiver region of the carrier medium,
• the predefined transceiver deflector of the transceiver region is configured to couple the second light emitted by the second light source into the carrier medium towards the measuring region,
• the detector is configured to determine a second intensity signal of the second wavelength,
• the evaluator is configured to determine a blood oxygen saturation as a medical characteristic value from the first intensity signal and the second intensity signal,
• the second wavelength is in a range of 850 nm to 1000 nm,
• the detector is configured to distinguish between the first wavelength and the second wavelength,
• the spectrometry device further comprising a housing configured to protect the transceiver region and the transceiver device from outside light,
• wherein
• each of the predefined transceiver deflector and the predefined measuring deflector have at least one optical grating, and
• the at least one optical grating is one of a surface holographic grating and a volume holographic grating having a multiplex diffraction structure for at least the first wavelength and the second wavelength.