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Spectroscopy is widely used in biomedicine, agriculture, remote sensing, industrial process monitoring, etc. The emerging on‐chip integration techniques further extend these applications to on‐site and portable operating modes. However, realizing high‐applicability and low‐cost spectroscopy chips is still a major challenge particularly in infrared due to the requirements on a large number of spectral channels. Here, a compact and low‐cost near‐infrared spectral sensing platform is demonstrated, releasing the burden of scaling up the spectral channel and simultaneously keeping a high accuracy in chemical classification. The monolithically integrated spectral sensor consists of a small amount of plasmon‐modulated narrowband photodetection units and operates with on‐chip photoelectric responses via a statistical machine learning method. Both plasmonic resonances with low spectral correlation and advanced regression algorithms contribute to high sensing accuracy in the case of limited hardware resources. Chemical concentration quantification, plastic sorting, and scanning spectral imaging are realized using such a sensor with up to twelve spectral channels. This concept avoids the uncertainty of various spectral reconstruction algorithms, high cost, and processing complexity and therefore provides promising strategies for miniaturized spectral sensing platforms. [ABSTRACT FROM AUTHOR]

By combining information such as genomics, proteomics, and metabolomics data, multiomics methodologies have the potential to reveal the otherwise invisible processes of carcinogenesis. Using these data, a new-generation point-of-care (POC) device may support patient care through rapid diagnosis involving accurate and simultaneous multiomics measurements. In this work, we present a proof-of-concept portable system capable of measuring a metabolite (glutamate) and a protein [proteolytically active prostate-specific antigen (aPSA)] simultaneously on a single device in a 2-min interval using on-chip optical methods. The device has the potential to improve the current diagnostic pathways of prostate cancer (PCa) by reducing the high false-positive rate with the widely used total prostate-specific antigen (tPSA) test. We demonstrate a simultaneous assay of glutamate and aPSA in buffer and synthetic urine. For the glutamate assay, the limit of detection (LOD) and resolution were found to be 0.9 and $2.7 {\boldsymbol {\mu }}\text{M}$ , respectively. The LOD and resolution for aPSA were 0.5 and 2.0 ng $/$ ml, respectively. The LOD and resolution achieved using this device are, therefore, in line with human physiological ranges. The platform is suitable for accommodating two independent optical assays, and, therefore, chemistry can be modified to measure different analytes regardless of their nature. This technological breakthrough has the potential to deliver an accurate multiomics portable device for PCa and may be extended to other diseases. [ABSTRACT FROM AUTHOR]

An approach for matching the transconductance characteristics of CMOS ion-sensitive field-effect transistor (ISFET) arrays is discussed. The ISFET array is found to have a measured sensitivity of 46 mV/pH after matching.

We report the experimental in situ characterization of 30--40 MHz and 868 MHz wireless transmission schemes for ingestible capsules, in porcine carcasses. This includes a detailed study of the performance of a magnetically coupled near-field very high-frequency (VHF) transmission scheme that requires only one eighth of the volume and one quarter of the power consumption of existing 868-MHz solutions. Our in situ measurements tested the performance of four different capsules specially constructed for this study (two variants of each transmission scheme), in two scenarios. One mimicked the performance of a body-worn receiving coil, while the other allowed the characterization of the direction-dependent signal attenuation due to losses in the surrounding tissue. We found that the magnetically coupled near-field VHF telemetry scheme presents an attractive option for future, miniturized ingestible capsules for medical applications. Index Terms--Biomedical telemetry, finite-difference time-domain (FDTD) methods, UHF radio propagation, VHF radio propagation.

In this paper, we present a radiotelemetry sensor, designed as a lab-in-a-pill, which incorporates a two-channel micro-fabricated sensor platform for real-time measurements of temperature and pH. These two parameters have potential application for use in remote biological sensing (for example they may be used as markers that reflect the physiological environment or as indicators for disease, within the gastrointestinal tract). We have investigated the effects of biofouling on these sensors, by exploring their a response time and sensitivity in a model in vitro gastrointestinal system. The artificial gastric and intestinal solutions used represent a model both for fasting, as well as for the ingestion of food and subsequent digestion to gastrointestinal chyme. The results showed a decrease in pH sensitivity after exposure of the sensors for 3 h. The response time also increased from an initial measurement time of 10 s in pure GI juice, to ca. 25 s following the ingestion of food and 80 s in simulated chyme. These in vitro results indicate that changes in viscosity in our model gastrointestinal system had a pronounced effect on the unmodified sensor. Index Terms--Biofouling, in vitro measurements, lab-in-a-pill, microfabricated sensors, radio telemetry.

A telemetry microsystem, including multiple sensors, integrated instrumentation and a wireless interface has been implemented. We have employed a methodology akin to that for System-on-Chip microelectronics to design an integrated circuit instrument containing several 'intellectual property' blocks that will enable convenient reuse of modules in future projects. The present system was optimized for low-power and included mixed-signal sensor circuits, a programmable digital system, a feedback clock control loop and RF circuits integrated on a 5 mm x 5 mm silicon chip using a 0.6 [micro]m, 3.3 V CMOS process. Undesirable signal coupling between circuit components has been investigated and current injection into sensitive instrumentation nodes was minimized by careful floor-planning. The chip, the sensors, a magnetic induction-based transmitter and two silver oxide cells were packaged into a 36 mm x 12 mm capsule format. A base station was built in order to retrieve the data from the microsystem in real-time. The base station was designed to be adaptive and timing tolerant since the microsystem design was simplified to reduce power consumption and size. The telemetry system was found to have a packet error rate of 10-3 using an asynchronous simplex link. Trials in animal carcasses were carried out to show that the transmitter was as effective as a conventional RF device whilst consuming less power. Index Terms--Biomedical telemetry, laboratory-in-a-pill, microsystems, system-on-chip, very-large-scale integration.

This paper describes the design and implementation of a system-on-chip digital pH meter, for use in a wireless capsule application. The system is organized around an 8-bit microcontroller, designed to be functionally identical to the Motorola 6805. The analog subsystem contains a floating-electrode ISFET, which is fully compatible with a commercial CMOS process. On-chip programmable voltage references and multiplexors permit flexibility with the minimum of external connections. The chip is designed in a modular fashion to facilitate verification and component re-use. The single-chip pH meter can be directly connected to a personal computer, and gives a response of 37 bits/pH, within an operating range of 7 pH units. Index Terms--CMOS, ISFET, pH, system-on-chip.

A novel microelectronic 'pill' has been developed for in situ studies of the gastro-intestinal tract, combining microsensors and integrated circuits with system-level integration technology. The measurement parameters include real-time remote recording of temperature, pH, conductivity, and dissolved oxygen. The unit comprises an outer biocompatible capsule encasing four microsensors, a control chip, a discrete component radio transmitter, and two silver oxide cells (the latter providing an operating time of 40 h at the rated power consumption of 12.1 mW). The sensors were fabricated on two separate silicon chips located at the front end of the capsule. The robust nature of the pill makes it adaptable for use in a variety of environments related to biomedical and industrial applications. Index Terms--Microelectronic pill, microsensor integration, mobile analytical microsystem, multilayer silicon fabrication, radiotelemetry, remote in situ measurements.

For the purpose of low-power data acquisition in a small footprint microsystem, a method for variable-rate data sampling is proposed. It indicates that the effectiveness of the variable-rate sampling (VRS) technique is dependent on the high-frequency content of the data being sampled.