In a world with a growing need for rapid medical diagnosis, point-of-care devices based on optics have become an interesting solution. Moreover, the low cost, simplicity, and ease of use also become essential to be applied in a clinical environment. Nowadays, smartphones are an attractive, user-friendly option, but the rapid changes in the models, the variety of brands, and the risk of contamination of personal smartphones in a clinical situation make this choose not the best one. Single-board computers as Raspberry Pi can be an alternative for a low-cost imaging device that allows image acquisition, visualization, and processing. This study describes a portable system capable of acquiring and processing white light and fluorescence images, suitable for clinical purposes. The system consists of a single-board computer (Raspberry Pi 3B+, Raspberry Pi Foundation, UK) coupled to a digital camera and a touchscreen display. The portable device comprises six violet LEDs (emitting at 407 nm) to excite the tissue and a long-pass optical filter to acquire the fluorescence images; four white LEDs to obtain the white light one, besides a digital camera to perform the acquisition itself. The images are saved in the singleboard computer, where an algorithm written in Python (Python Foundation) calibrates the camera, acquires, and processes the acquired images, interacting with the user through touch with a GUI. Being a portable, easy to use, low-cost system, this device is convenient to be used in a clinical environment and allows a fast diagnosis and the possibility to be reproduced for widespread point-of-care use.
This paper describes the assembly and characterization of a system to treat and monitor ALA-based photodynamic therapy, using near-infrared fluorescence images for photosensitizer monitoring. The system is portable, user friendly and low cost, using a diode laser emitting at 633 nm as treatment light, capable to delivery up to 150 mW/cm2 at the lesion surface. The PpIX fluorescence is excited by the treatment light itself, and detected by camera in real-time. Since the excitation and emission wavelengths are in the red-NIR spectral regions, the penetration into the skin is improved and the volume measured by the fluorescence images is larger when compared to the widely used violet excitation.
In this work we show that the fiber optic angular displacement sensor is capable of Lamb wave detection, with results
comparable to a piezoelectric transducer. Therefore, the fiber optic sensor has a great potential to be used as the Lamb
wave ultrasonic receiver and to perform non-destructive and non-contact testing.