NON-INVASIVE BLOOD GLUCOSE MEASUREMENT

摘要

A method and apparatus for non-invasive measurement of blood glucose concentration based on producing a polarized-modulated laser beam, measuring a phase difference introduced, e.g., by a finger (F) or a ear lobule (E) of a subject, measuring the phase difference between a reference signal (SR) and a probe/measurement signal (SP, SM), and processing the obtained data which are then presented as blood glucose concentration. Apparatus includes an infrared laser source (22), a polarized frequency shifter (24) which produces a polarized-modulated infrared laser beam, a piezoelectric transducer (26) for driving the polarizing frequency shifter (24), and an optical transducer (30) with a glucose measuring head (32). The latter has an optical input for receiving the laser beam and a balanced receiver (62). The probe beam, after passing through the finger, is converted into a probe electrical signal, the reference beam is converted into a reference electrical signal, the probe and reference electrical signals are compared, and the obtained phase difference is processed by an electronic signal processing unit (34) which presents the results in the form of blood glucose concentration. Alternate embodiments based on measurement of circular dichroism caused by the presence of glucose in blood are included. The polarized frequency shifter may be crystal optic or fiber-optic based.