Lightweight Deep Neural Network for Joint Learning of Underwater Object Detection and Color Conversion.

Underwater image processing has been shown to exhibit significant potential for exploring underwater environments. It has been applied to a wide variety of fields, such as underwater terrain scanning and autonomous underwater vehicles (AUVs)-driven applications, such as image-based underwater object detection. However, underwater images often suffer from degeneration due to attenuation, color distortion, and noise from artificial lighting sources as well as the effects of possibly low-end optical imaging devices. Thus, object detection performance would be degraded accordingly. To tackle this problem, in this article, a lightweight deep underwater object detection network is proposed. The key is to present a deep model for jointly learning color conversion and object detection for underwater images. The image color conversion module aims at transforming color images to the corresponding grayscale images to solve the problem of underwater color absorption to enhance the object detection performance with lower computational complexity. The presented experimental results with our implementation on the Raspberry pi platform have justified the effectiveness of the proposed lightweight jointly learning model for underwater object detection compared with the state-of-the-art approaches.

A High-Precision CMOS Temperature Sensor with Thermistor Linear Calibration in the (-5 °C, 120 °C) Temperature Range.

A high-precision Complementary Metal-Oxide-Semiconductor (CMOS) temperature sensor for (−5 °C, 120 °C) temperature range is designed and analyzed in this investigation. The proposed design is featured with a temperature range selection circuit so that the thermistor linear circuit automatically switches to a corresponding calibration loop in light of the temperature range besides the analysis of the calibration method. It resolves the problem that the temperature range of a single thermistor temperature sensor is too small. Notably, the output of the proposed design also attains a high linearity. The measurement results in a thermal chamber justifying that the output voltage is 1.96 V to 4.15 V, the maximum linearity error ≤1.4%, and the worst temperature error ≤1.1 °C in the temperature range of −5 °C to 120 °C.

Highly Sensitive FPW-Based Microsystem for Rapid Detection of Tetrahydrocannabinol in Human Urine.

This paper presents a highly sensitive flexural plate-wave (FPW)-based microsystem for rapid detection of tetrahydrocannabinol (THC) in human urine. First, a circular-type interdigital transducer (IDT) was integrated with a circular-type silicon-grooved reflective grating structure (RGS) to reduce insertion loss. Then, with lower insertion loss (-38.758 dB), the FPW device was used to develop a novel THC biosensor, and the results reveal that this FPW-THC biosensor has low detection limit (1.5625 ng/mL) and high mass-sensitivity (126.67 cm²/g). Finally, this biosensor was integrated with field-programmable gate array (FPGA) board and discrete components for prototyping a FPW readout system, whose maximum error was 12.378 kHz to ensure that the linearity of detection up to R-square is equal to 0.9992.

Noninvasive control of the power transferred to an implanted device by an ultrasonic transcutaneous energy transfer link.

Ultrasonic transcutaneous energy transfer is an effective method for powering implanted devices noninvasively. Nevertheless, the amount of power harvested by the implanted receiver is sensitive to the distance and orientation of the external transmitting transducer attached to the skin with respect to the implanted receiving transducer. This paper describes an ultrasonic power transfer link whose harvested power is controlled by an inductive link. A small (5 µF) storage capacitor voltage, which is part of the implanted unit, is allowed to swing between 3.8 and 3.5 V using hysteretic control. The two control states are indicated by excitation (while the implanted storage capacitor voltage decreases) or the absence of excitation of an implanted coil that is magnetically coupled to an external coil attached to the skin surface. A 35 mW Ultrasonic Transcutaneous Energy Transfer link was fabricated using two piezoelectric transducers of equal size (Fuji Ceramics C-2 PZT disc 15 mm × 3 mm) operated at a vibration frequency of 720 kHz. By applying the proposed hysteretic control, the captured power was effectively regulated for implantation depths of up to 85 mm.

A protein concentration measurement system using a flexural plate-wave frequency-shift readout technique.

A protein concentration measurement system with two-port flexural plate-wave (FPW) biosensors using a frequency-shift readout technique is presented in this paper. The proposed frequency-shift readout method employs a peak detecting scheme to measure the amount of resonant frequency shift. The proposed system is composed of a linear frequency generator, a pair of peak detectors, two registers, and a subtractor. The frequency sweep range of the linear frequency generator is limited to 2 MHz to 10 MHz according to the characteristics of the FPW biosensors. The proposed frequency-shift readout circuit is carried out on silicon using a standard 0.18 µm CMOS technology. The sensitivity of the peak detectors is measured to be 10 mV. The power consumption of the proposed protein concentration measurement system is 48 mW given a 0.1 MHz system clock.

Ultrasonic transcutaneous energy transfer using a continuous wave 650 kHz Gaussian shaded transmitter.

This paper proposes ultrasonic transcutaneous energy transfer (UTET) based on a kerfless transmitter with Gaussian radial distribution of its radiating surface velocity. UTET presents an attractive alternative to electromagnetic TET, where a low power transfer density of less than 94 mW/cm(2) is sufficient. The UTET is operated with a continuous wave at 650 kHz and is intended to power devices implanted up to 50mm deep. The transmitter was fabricated using a 15 mm diameter disc shape PZT (Lead Zirconate Titanate) element (C-2 grade, Fujiceramics Corporation Tokyo Japan), in which one surface electrode was partitioned into six equal area electrodes ( approximately 23 mm(2) each) in the shape of six concentric elements. The UTET was experimented using pig muscle tissue, and showed a peak power transfer efficiency of 39.1% at a power level of 100 mW. An efficient (91.8%) power driver for the excitation of the transmitter array, and an efficient rectifier (89%) for the implanted transducer are suggested. To obtain the pressure field shape, the Rayleigh integral has been solved numerically and the results were compared to finite element simulation results. Pressure and power transfer measurements within a test tank further confirm the effectiveness of the proposed UTET.

An implantable bi-directional wireless transmission system for transcutaneous biological signal recording.

This study presents an implantable microcontroller-based bi-directional transmission system with an inductive link designed for biological signal sensing. The system comprises an external module and an implantable module. The external module incorporates a high-efficiency class-E transceiver with amplitude modulation scheme and a data recovery reader. The transceiver sends both power and commands to the implanted module, while the reader recovers the recorded biological signal data and transmits the data to a personal computer (PC) for further data processing. To reduce the effects of interference induced by the 2 MHz carrier signal, the implanted module uses two separate coils to perform the necessary two-way data transmission. The outward backward telemetry circuitry of the implanted module was based on the loadshift keying (LSK) technique. The transmitted sensed signal had a 10-bit resolution and a read-out rate of 115 kbps. The implanted module, measuring 4.5 x 3 x 1.2 cm3, was successfully verified in animal experiment in which the electroneurogram (ENG) signal was recorded from the sciatic nerve of New Zealand rabbits in response to nociceptive stimulation of foot. The reliable operating distance of the system was within about 3.5 cm with an efficiency of around 25%. Our present study confirms that the proposed biological signal sensing device is suitable for various implanted applications following an appropriate biocompatible packaging procedure.