Proximity Sensing Electronic Skin: Principles, Characteristics, and Applications.

The research on proximity sensing electronic skin has garnered significant attention. This electronic skin technology enables detection without physical contact and holds vast application prospects in areas such as human-robot collaboration, human-machine interfaces, and remote monitoring. Especially in the context of the spread of infectious diseases like COVID-19, there is a pressing need for non-contact detection to ensure safe and hygienic operations. This article comprehensively reviews the significant advancements in the field of proximity sensing electronic skin technology in recent years. It covers the principles, as well as single-type proximity sensors with characteristics such as a large area, multifunctionality, strain, and self-healing capabilities. Additionally, it delves into the research progress of dual-type proximity sensors. Furthermore, the article places a special emphasis on the widespread applications of flexible proximity sensors in human-robot collaboration, human-machine interfaces, and remote monitoring, highlighting their importance and potential value across various domains. Finally, the paper provides insights into future advancements in flexible proximity sensor technology.

Study on reconstruction and analytical method of seawater radioactive gamma spectrum.

Gamma detector detection technology based on NaI(Tl) scintillation crystal has become a popular research topic and has been applied in the field of marine radioactive environment automatic monitoring because of its advantages of low power consumption, low cost and strong environmental adaptability. However, insufficient energy resolution of the NaI(Tl) detector and great Compton scattering in the low-energy region caused by the abundance of natural radionuclides in seawater hinder the automatic analysis of radionuclides in seawater. This study adopts the combination of theoretical derivation, simulation experiment, water tank test and seawater field test, establishing an effective and feasible spectrum reconstruction method. The measured spectrum in seawater is regarded as the output signal formed by the convolution of the incident spectrum and the detector response function. The acceleration factor p is introduced to construct the Boosted-WNNLS deconvolution algorithm, which is used to iteratively reconstruct the spectrum. The analysis results of the simulation test, water tank test and field test meet the radionuclide analysis speed and accuracy requirements for the in-situ automatic monitoring of seawater radioactivity. The spectrum reconstruction method in this study converts the physical problem of insufficient detection accuracy of spectrometer in the practical application into a mathematical problem of deconvolution solution, restores the original radiation information in seawater, and improves the resolution of the seawater gamma spectrum.

New method for calibrating optical dissolved oxygen sensors in seawater based on an intelligent learning algorithm.

Oxygen sensors based on luminescence quenching are the most commonly used instruments for in situ measurement in seawater due to their accuracy and long-term stability. The calibration method of the sensor is crucial for their accuracy. Conventional methods exhibit some defects, such as strict control of calibration conditions and cumbersome and time-consuming operation. To improve calibration operation and obtain good calibration results, a new calibration method was proposed for the optical dissolved oxygen sensor in seawater based on an intelligent learning algorithm. The sensor to be calibrated and the reference sensor were deployed in the water for synchronous measurements. The calibration system consisted of a temperature-regulated device and a sampling method to improve calibration operation. An intelligent learning algorithm was used to train the calibration data and model the oxygen response of the sensor. Calibration and test results in both laboratory and field showed that the new calibration method is feasible and efficient. It is highly significant for sensor development and in situ measurement in seawater.

Research on minimum detectable activity (MDA) of underwater gamma spectrometer for radioactivity measurement in the marine environment.

To improve the capability of underwater gamma spectrometer to quantify radiation levels slightly above the background radiation in the seawater, the minimum detection activity (MDA) and factors including the background count, detection efficiency and acquisition time were studied using Monte Carlo simulation and field experiments. The simulation results show that the crystal type selected in the spectrometer and its volume, enclosure materials of the spectrometer and its thickness all affect the marine detection efficiency in in-situ measurement, and thus determine MDA of the underwater gamma spectrometer. The acquisition time and the placement depth of the spectrometer in the seawater also affect the MDA in the in-situ measurement. Some research data and suggestions on design and use of underwater gamma spectrometer were presented, which are of guiding significance for the in-situ radioactivity measurement in the marine environment.

Development and deployment of an autonomous sensor for the in-situ radioactivity measurement in the marine environment.

An autonomous sensor for the in-situ radioactivity measurement is developed，based on NaI(Tl) crystal, to detect the activity concentrations of natural and anthropogenic radionuclides in seawater. Its electronics module, integral enclosure and spectrum analysis were presented. The energy, resolution and efficiency were calibrated. Monte Carlo simulation and the minimum detection estimations were realized. The sensor was tested in the water tank and then successfully deployed for the continuous monitoring in the marine environment in Qingdao offshore for the performance test, background measurement and environmental survey. Some results were deduced from the gamma ray spectra and discussed in comparison with those from the laboratory and literatures.

Automated spectra analysis of in situ radioactivity measurements in the marine environment using NaI(Tl) detector.

The NaI(Tl) detector has become the main way of research and application of in-situ radioactivity measurement in the marine environment due to many advantages on detection efficiency, power consumption, cost and applicability. But for the poor energy resolution and there is a high background in the low energy region of the spectrum measured mainly originating from the Compton scattering of natural radionuclides such as 40K with high concentrations in seawater, it is difficult and also an interesting topic for NaI(Tl) detector to identificate the radionuclides and calculate them in seawater by analyzing the spectra measured. In this paper, an in situ NaI(Tl) detector developed for the marine environment was energy, resolution and efficiency calibrated. The detection response matrix was calculated by taking all the responsible processes and interactions of gamma rays in water as well as in the detector into account using Monte Carlo simulation method. And then an improved Richardson-Lucy (R-L) deconvolution algorithm was proposed to reconstruct the gamma spectrum measured in the seawater to remove as efficiently as possible the background counts into the corresponding photopeaks. The original spectrum was transformed from poor energy resolution to the corresponding deconvolution spectrum of the high energy resolution with several isolated photopeaks. The experiments of synthetic spectrum and measured spectrum both showed promising results for the radionuclide qualitative and quantitative analysis.

The exact estimation of visual acuity by VEP technology: a report of 726 cases of eye injury.

This study explored the accuracy of using visual evoked potentials (VEP) technology for visual acuity estimation. The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group, and the healthy eyes as the control group. The least signal visual angle (LSVA), and amplitude and latency of P(100) were chosen as test indexes. The results under different experimental conditions were recorded by PRVEP technology. All data collected were processed and analyzed by SPSS software. The results showed that the coincidence between subjective and VEP visual acuity was 96.7% in control group, but there was very significant difference in experimental group. It was concluded that with the regression formulation for the amplitude of P(100) and vision under LSVA, visual acuity can be estimated more accurately and impartially.

The Exact Estimation of Visual Acuity by VEP Technology: A Report of 726 Cases of Eye Injury / 华中科技大学学报（医学）（英德文版）

This study explored the accuracy of using visual evoked potentials (VEP) technology for visual acuity estimation. The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group, and the healthy eyes as the control group. The least signal visual angle (LSVA), and amplitude and latency of P100 were chosen as test indexes. The results under different experimental conditions were recorded by PRVEP technology. All data collected were processed and analyzed by SPSS software. The results showed that the coincidence between subjective and VEP visual acuity was 96.7% in control group, but there was very significant difference in experimental group. It was concluded that with the regression formulation for the amplitude of P100 and vision under LSVA, visual acuity can be estimated more accurately and impartially.