Ultra-miniature (diameter: 6 mm, thickness: 5 mm) low-cost (1,000 EUR) point-one-shot mid-infrared Fourier spectroscopic imager for ear clip type non-invasive blood glucose sensors

摘要

We propose an ultrasonic-assisted point-one-shot mid-infrared Fourier spectroscopy device involving an ultrasonic liquid-cell and point-one-shot Fourier spectroscopy (diameter: 6 mm, thickness: 5 mm) for ear clip type non-invasive blood glucose sensors, at a low cost (approximately 1,000 EUR). As the prevalence of diabetes increases over time, methods for non-invasive monitoring of blood glucose concentration in daily life are increasingly important for diabetes control and prevention. However, there are currently no sensors for non-invasively detecting biological components in daily environments. In the current study, we propose a point-one-shot Fourier spectroscopy method comprising one objective lens and a camera. The objective lens is a spherical lens at the front side and a dual-axis wedge prism inclined along the horizontal and vertical axes. An objective beam is collimated by the objective lens, with a difference in optical path length caused by the wedge prism. This device can be used to obtain two-dimensional spatial fringe patterns. Conventional one-shot Fourier spectroscopy produces one-dimensional fringe patterns in the horizontal direction of the array device. Thus, the maximum optical path length is limited by the number of pixels in only the horizontal line of the array device. However, our proposed point-one-shot Fourier spectroscopy device can produce an interferogram with longer maximum optical path lengths compared with conventional devices because horizontal lines at difference rows are connected by the same phase pixel. Thus, spectroscopic imaging devices can be produced at a low cost because low-resolution cameras (e.g., 80 × 80 pixels) can be used for spectroscopy.