Low-cost solutions for the detection of ammonia and its related compounds are of deep interest, due to several application contexts requiring suitable approaches for its detection, both as a direct ...product of industrial or biological processes, as well as a byproduct of complex reactions. This paper addresses the need of ammonia detection for the indirect estimation of phenylalanine, which is of interest in the context of Phenylketonuria disorder. The main idea behind the proposed approach is to exploit the ammonia produced by the enzymatic reaction phenylalanine-phenylalanine ammonia-lyase. The sensing methodology investigated through this paper is based on a chemo-capacitive readout strategy, implemented by a stack structure using interdigited electrodes and a functional layer of Yttria-Stabilized Zirconia. The sensor behavior is addressed, along with a dedicated signal processing allowing to retrieve a reliable information on the target media from the sensor output. The system shows a responsivity of 0.077 pF/μM, a resolution of 2.5 μM and an accuracy of 22.5 μM in the 3σ level.
As bacterial infections are still a risk for human health, the market offers different systems able to detect bacterial growth in biological samples. One of them is the WASPLab automated platform, ...commercialized by COPAN Italia S.p.A., which combines growth detection capabilities with high levels of automation and connectivity, in compliance with Industry 4.0 principles. In this paper, we describe a study carried out on a system, whose operation relies on impedance measurements, to evaluate the possibility of its integration to the WASPLab. This integration would provide a larger quantity of data about bacterial growth to the user and would optimize analysis process. By using this system, we observed the growth of S. aureus in Petri dishes, while they were directly inside one of the WASPLab incubators. System provided enough information to successfully detect bacterial growth with detection time equal to three, four and a half, and six hours when initial pathogen concentration was in the order of 4.5... 10 8 CFU ml, \ 4.5... 10 7 CFU ml, and 4.5... 10 6 CFU/ml, respectively. Results highlight that the measuring system could work together with the WASPLab, enhancing its monitoring performances, connectivity, and flexibility. This contributes to the realization of an architecture compliant with the model of the Factory of the Future.
Diagnosing the presence of bacteria in a biological sample is a task to accomplish as early as possible, since bacterial infections still represent a serious threat to human health. In the market, ...there are commercial systems carrying out pre-analytical tests on biological specimens. An example is provided by the WASPLab, by COPAN Italia S.p.A., which monitors bacterial growth on Petri dishes that contain the samples, by taking and processing images of one dish at a time in a completely automated way. In this paper, we propose a newly monitoring sensor system for all the Petri dishes at the same time for the detection of bacterial growth with the aim of integrating it directly in the WASPLab. It could permit to obtain quantitative information about bacterial activity in real time directly inside the incubator, offering a more rapid and complete diagnosis response and avoiding the movement of the samples. In addition, the user can set measurement parameters according to his/her needs. This allows the system reaching a great level of flexibility. We tested our solution in two ways. First, we analyzed the behavior of the proposed solution comparing the output signals with the data obtained using an impedance analyzer (HP4194A) as reference. We obtained an average deviation equal to 0.768 Ω in magnitude and 0.059 ° in phase angle. Second, we carried out a 24-hour test to monitor the activity of Staphylococcus Aureus AT C 6538 in a climate chamber. We found that our system succeeded in observing bacterial growth, with an early detection time of 4 hours. Research is undergoing to integrate the proposed system in the WASPLab.
Bacterial infections are still one of the main causes of disease around the world. For this reason, the early diagnosis of an infection becomes fundamental for patient's health. In the market, there ...are very advanced systems that perform such analyses on biological samples, such as WASPLab, by COPAN Italia S.p.A. This platform monitors the growth of bacterial cultures, in a fully automated way, by taking periodic images of the Petri dishes inoculated with bacteria. In this work, we describe the preliminary study on a concept sensor-based system that, when optimized, could be integrated in the WASPLab, to provide a more rapid and complete diagnosis response. The system measures the electrical impedance related to a Petri dish instrumented with an electrode-based sensor, only at two fixed frequencies. In addition, it presents quantitative information associated to bacterial growth to the user in real time. Such information comes under the form of parameters derived from impedance response. We tested the system through a specific experimental analysis. During repeated tests, we inoculated a Petri dish with an initial concentration equal to 1.5 McFarland of Staphylococcus Aureus ATC 6538. We have been monitoring its growth for 18 hours, while the dish was staying in an incubator at 35°C, by measuring the impedance at 100 Hz and 1000 Hz. After six hours, we observed a variation higher than 10% on the best parameter, which allowed finding a growth detection time of four hours. Achieved results demonstrate the validity of our approach, paving the way to the possibility to integrate our device in the WASPLab, to enhance its flexibility and diagnosis capabilities.
In this paper, the development of a system capable of tracking finger motion is presented. The proposed wearable tracking unit is placed on the finger and it is wirelessly powered without using ...cables or batteries, thus enhancing freedom of movement. The system is comprised by two sections: a measurement unit and a wireless power transfer apparatus. The measurement unit consists of an electronic board able to measure, acquire and transmit sensors signals; a stretch sensor and an inertial measurement unit are integrated on the measurement unit. Furthermore, the wireless power transfer apparatus is implemented by means of inductively-coupled resonant circuits. A prototype of the developed system is characterized by experimental tests. Results show the feasibility of the proposed approach. The measuring system can track finger movement with a sample rate of 30 Hz, while the wireless power transfer system demonstrates the capability of transferring 67.72 mW, necessary to power the measurement unit, at a maximum distance of about 8 cm.
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