Hospitals currently rely on simple human visual inspection for assessing cleanliness of surgical instruments. Studies showed that surgical site infections are in part attributed to inadequate cleaning of medical devices. Standards groups recognize the need to objectively quantify the amount of residues on surgical instruments and establish guidelines. We developed a portable technology for the detection of contaminants on surgical instruments through fluorescence following cleaning. Weak fluorescence signals are usually detected in the obscurity only with the lighting of the excitation source. The key element of this system is that it works in ambient lighting conditions, a requirement to not disturb the normal workflow of hospital reprocessing facilities. A biocompatible fluorescent dye is added to the detergent and labels the proteins of organic residues. It is resistant to the harsh environment in a washer-disinfector. Two inspection devices have been developed with a 488nm laser as the excitation source: a handheld scanner and a tabletop station using spectral-domain and time-domain ambient light cancellation schemes. The systems are eye safe and equipped with image processing and interfacing software to provide visual or audible warnings to the operator based on a set of adjustable signal thresholds. Micron-scale residues are detected by the system which can also evaluate soil size and mass. Unlike swabbing, it can inspect whole tools in real-time. The technology has been validated in an independent hospital decontamination research laboratory. It also has potential applications in the forensics, agro-food, and space fields. Technical aspects and results will be presented and discussed.
Anthocyanins are water soluble pigments in plants that are recognized for their antioxidant property. These pigments are
found in high concentration in cranberries, which give their characteristic dark red color. The Total Anthocyanin
concentration (TAcy) measurement process requires precious time, consumes chemical products and needs to be
continuously repeated during the harvesting period. The idea of the digital TAcy system is to explore the possibility of
estimating the TAcy based on analysing the color of the fruits. A calibrated color image capture set-up was developed
and characterized, allowing calibrated color data capture from hundreds of samples over two harvesting years (fall of
2007 and 2008). The acquisition system was designed in such a way to avoid specular reflections and provide good
resolution images with an extended range of color values representative of the different stages of fruit ripeness. The
chemical TAcy value being known for every sample, a mathematical model was developed to predict the TAcy based on
color information. This model, which also takes into account bruised and rotten fruits, shows a RMS error of less than
6% over the TAcy interest range [0-50].