A small form-factor, lightweight wireless capsule endoscope (WCE) system with body channel communication (BCC) transceiver ICs is proposed for VGA-resolution image transferring and capsule localization. The transceiver ICs are composed of capsule chip and receiver chip, implemented in a 65-nm CMOS process. In the capsule side, the proposed system provides 360° image capturing through four-camera integration to reduce the miss rate. Also, a dual-band pulse-shaping BCC transmitter is proposed to enable low-power (<1 mW), high-speed (80 Mb/s) image transmission. In the receiver side, contact attenuation compensated-received signal strength indicator (CAC-RSSI) is proposed to increase the capsule localization accuracy. The external system is composed of eight-receiver nodes that allow signal demodulation and localization of the capsule. To reduce transceiver payload and system power consumption, image encoder is implemented in the capsule. The transceiver IC is integrated into the capsule system and verified with body mimicking phantom. The proposed system satisfies compatibility with medical grade diagnosis by operating longer than 8 h with 4 fps and 12 h with 2 fps with conventional two silver oxide 55-mA· h coin batteries. The tested localization accuracy shows less than sub-centimeter range.

The natural compound eye system has many outstanding properties, such as a more compact size, wider-angle view, better capacity to detect moving objects, and higher sensitivity to light intensity, compared to that of a single-aperture vision system. Thanks to the development of micro- and nano-fabrication techniques, many artificial compound eye imaging systems have been studied and fabricated to inherit fascinating optical features of the natural compound eye. This paper provides a review of artificial compound eye imaging systems. This review begins by introducing the principle of the natural compound eye, and then, the analysis of two types of artificial compound eye systems. We equally present the applications of the artificial compound eye imaging systems. Finally, we suggest our outlooks about the artificial compound eye imaging system.

This article presents a wireless neural implant with body-coupled (BC) data transmission and power delivery for freely behaving animals and incorporates a precision front end for high-quality neural recordings. The neural implant utilizes the body as a wireless transmission medium where it only needs small electrodes for data transmission and power delivery. An external device with patch electrodes can then be placed far away from the implant without the need for precise alignment. Furthermore, a four-channel continuous-time delta–sigma modulator (CT- $\Delta \Sigma \text{M}$ ) is integrated into the system for precision neural recordings. Each neural recording CT- $\Delta \Sigma \text{M}$ achieves an 82.3-dB signal-to-noise and distortion ratio (SNDR) and an 83.3-dB dynamic range (DR) while consuming only 8.6- $\mu \text{W}$ at a signal bandwidth of 10 kHz. The neural implant integrated circuit (IC) is fabricated in a 0.11- $\mu \text{m}$ CMOS with a high-density capacitor option, and the BC data receiver (RX) IC is implemented in a 0.18- $\mu \text{m}$ CMOS. The implant IC occupies a chip area of 4 $\text {mm}^{2}$ , including a 5-nF on-chip capacitor, and draws 280 $\mu \text{A}$ from a 2.3-V supply with a working data transmitter (TX) electrode. By exploiting direct-digital signaling for data transmission, the neural implant achieves a data rate of 20.48 Mb/s and a wireless power recovery of 644 $\mu \text{W}$ , resulting in an energy efficiency of 32 pJ/b. The entire neural implant system has been successfully verified by both electrical and in vivo measurements, while the wirelessly recorded electrocorticography (ECoG) signals with the prototype neural implant inside a rat demonstrate the end-to-end functionality of the proposed system.

This study presents a system for assessing the freshness of meat with electrical impedance spectroscopy (EIS) in the frequency range of 125 Hz to 128 kHz combined with an image classifier for non-destructive and low-cost applications. The freshness standard is established by measuring the aerobic plate count (APC), 2-thiobarbituric acid reactive substances (TBARS), and composition analysis (crude fat, crude protein, and moisture) values of the microbiological detection to represent the correlation between EIS and meat freshness. The EIS and images of meat are combined to predict the freshness with the Adaboost classification and gradient boosting regression algorithms. As a result, when the elapsed time of beef storage for 48 h is classified into three classes, the time prediction accuracy is up to 85% compared to prediction accuracy of 56.7% when only images are used without EIS information. Significantly, the relative standard deviation (RSD) of APC and TBARS value predictions with EIS and images datum achieves 0.890 and 0.678, respectively.

When designing readout circuits for physiological signal measurement, one needs to understand that applications define the required signal quality and the circuit architecture. In addition, a clear understanding of electrode interface is as important as the circuit design since it is first and an integral part of the readout circuits. It is also necessary to be aware of signal aggressors so that they can be removed properly. The readout circuits are part of the overall system; therefore, various challenges and issues can be addressed in other parts of the system.

We present an energy-efficient reception and transmission scheme based on the exploitation of the conductive properties of the body for wireless neural interface applications. High efficiencies were achieved with: 1) a three-level clock-embedded direct digital signaling scheme in the transmitter (TX) and 2) with a squaring clock extraction enabling data recovery scheme using a clocked-comparator in the receiver (RX). Additionally, the output voltage of the TX was boosted to secure the link budget of the RX. As a result, the RX and TX consumed 62 and 566 μW, respectively, for a rated output power of 185 μW and achieved a maximum data rate of 16.7 Mb/s. These operational characteristics corresponded to the energy consumptions of 3.7 pJ per received bit and 34 pJ per transmitted bit, demonstrating a promising potential for use in implanted devices.