[Data-Driven Construction of Operation Evaluation System for Large Medical Equipment in Children's Hospital].

Objective: Through data collection and analysis, the method of evaluating the operation quality of large medical equipment in children's hospital is explored and suggestions on the use and configuration of large medical equipment is put forward. Methods: Collect the equipment operation data through the Internet of Things, and combine the hospital HIS, RIS, HRP and other information system data to establish the operation evaluation system of large medical equipment of children's hospital. CRITIC method is used to quantitatively evaluate single type of equipment and single equipment. Results: Hospital big data platform realizes the longitudinal analysis of the operation data of a single large equipment and forms a visual chart, which is displayed on the PC and mobile terminals. Municipal platform can conduct horizontal analysis on the equipment operation data to realize the comprehensive quantitative evaluation of the operation level of large equipment of children's hospital and put forward suggestions for use and configuration. Conclusion: A large equipment operation evaluation system for children's hospital is established through data collection and analysis, and the fine management level of large medical equipment is improved.

Speech signal enhancement based on deep learning in distributed acoustic sensing.

The fidelity of a speech signal deteriorates severely in a distributed acoustic sensing (DAS) system due to the influence of the random noise. In order to improve the measurement accuracy, we have theoretically and experimentally compared and analyzed the performance of the speech signal with and without a recognition and reconstruction method-based deep learning technique. A complex convolution recurrent network (CCRN) algorithm based on complex spectral mapping is constructed to enhance the information identification of speech signals. Experimental results show that the random noise can be suppressed and the recognition capability of speech information can be strengthened by the proposed method. The random noise intensity of a speech signal collected by the DAS system is attenuated by approximately 20 dB and the average scale-invariant signal-to-distortion ratio (SI-SDR) is improved by 51.97 dB. Compared with other speech signal enhancement methods, the higher SI-SDR can be demonstrated by using the proposed method. It has been effective to accomplish high-fidelity and high-quality speech signal enhancement in the DAS system, which is a significant step toward a high-performance DAS system for practical applications.

Recent Progress in Lithium-Ion Battery Safety Monitoring Based on Fiber Bragg Grating Sensors.

Lithium-ion batteries are widely used in a variety of fields due to their high energy density, high power density, long service life, and environmental friendliness. However, safety accidents with lithium-ion batteries occur frequently. The real-time safety monitoring of lithium-ion batteries is particularly important during their use. The fiber Bragg grating (FBG) sensors have some additional advantages over conventional electrochemical sensors, such as low invasiveness, electromagnetic anti-interference, and insulating properties. This paper reviews lithium-ion battery safety monitoring based on FBG sensors. The principles and sensing performance of FBG sensors are described. The single-parameter monitoring and dual-parameter monitoring of lithium-ion batteries based on FBG sensors are reviewed. The current application state of the monitored data in lithium-ion batteries is summarized. We also present a brief overview of the recent developments in FBG sensors used in lithium-ion batteries. Finally, we discuss future trends in lithium-ion battery safety monitoring based on FBG sensors.

Non-Intrusive Pipeline Flow Detection Based on Distributed Fiber Turbulent Vibration Sensing.

We demonstrate a non-intrusive dynamic monitoring method of oil well flow based on distributed optical fiber acoustic sensing (DAS) technology and the turbulent vibration. The quantitative measurement of the flow rate is theoretically acquired though the amplitude of the demodulated phase changes from DAS based on the flow impact in the tube on the pipe wall. The experimental results show that the relationships between the flow rate and the demodulated phase changes, in both a whole frequency region and in a sensitive-response frequency region, fit the quadratic equation well, with a max R2 of 0.997, which is consistent with the theoretical simulation results. The detectable flow rate is from 0.73 m3/h to 2.48 m3/h. The experiments verify the feasibility of DAS system flow monitoring and provide technical support for the practical application of the downhole flow measurement.

Research Progress in Distributed Acoustic Sensing Techniques.

Distributed acoustic sensing techniques based on Rayleigh scattering have been widely used in many applications due to their unique advantages, such as long-distance detection, high spatial resolution, and wide sensing bandwidth. In this paper, we provide a review of the recent advancements in distributed acoustic sensing techniques. The research progress and operation principles are systematically reviewed. The pivotal technologies and solutions applied to distributed acoustic sensing are introduced in terms of polarization fading, coherent fading, spatial resolution, frequency response, signal-to-noise ratio, and sensing distance. The applications of the distributed acoustic sensing are covered, including perimeter security, earthquake monitoring, energy exploration, underwater positioning, and railway monitoring. The potential developments of the distributed acoustic sensing techniques are also discussed.

High-power and high-energy Nd:YAG-Nd:YVO4 hybrid gain Raman yellow laser.

We present a simple and reliable method to successfully reconcile the average output power and pulse energy of the solid-state Raman yellow lasers. By virtue of the hybrid laser gain of Nd:YAG and Nd:YVO4 in an intracavity frequency-doubled Raman, much higher pumping is allowed and nearly linear polarized fundamental and Stokes waves can be delivered for efficient non-critical phase matching. 7.6 W of yellow output at 588 nm is obtained under incident pump power of 42.0 W at the pulse repetition frequency (PRF) of 110 kHz and the pulse energy reaches 0.41 mJ under the same incident pump power at the PRF of 10 kHz.

[Management System of Implantable Medical Device in Accordance with JCI Standard Based on HRP System].

JCI standard is the most professional and authoritative certification standard of medical quality and safety system in the world. HRP information system is a systematic hospital resource management platform which integrates the existing hospital information resources and establishes a set of unified, efficient, interconnected and information sharing operation and management of the hospital. In order to meet the requirements of closed-loop management of implantable medical devices in the JCI standard, our hospital has established a set of standards which based on the HRP system platform, including access permission, purchase application, entering and leaving the warehouse, bookkeeping charge, cost accounting and postoperative traceability of implanted medical device management system. HRP system improves the management level of implantable medical devices, and realizes the closed-loop management of the whole process of implantable medical devices.

Novel gas sensor combined active fiber loop ring-down and dual wavelengths differential absorption method.

A novel active fiber loop ring-down gas sensor combined with dual wavelengths differential absorption method is proposed. Two Distributed Feedback Laser Diodes (DFB LDs) with different wavelengths are employed. One LD whose wavelength covered with the absorption line of target gas is used for sensing. Another LD whose wavelength is centered outside the absorption line is used for reference. The gas absorption loss can be obtained by differencing the reference signal and sensing signal. Compared with traditional method of one wavelength employed, it can eliminate the influence of the cavity loss variety and photoelectric device drift in the system efficiently. An Erbium Doped Fiber Amplifier (EDFA) with Automatic Gain Control (AGC) is used to compensate the loss of the light in the ring-down cavity, which will increase the cavity round trips and improve the precision of gas detection. And two fiber Bragg gratings (FBGs) are employed to get rid of amplified spontaneous emission (ASE) spectrum noise as filters. The calibrating ethyne samples of different concentrations are measured with a 65 mm long gas cell in order to evaluate the effect of reference. The results show the relative deviation is found to be less than ± 0.4% of 0.1% ethyne when a certain additional loss from 0 to 1.2dB is introduced to the cavity and the relative deviation of measured concentration is less than ± 0.5% over 24 hours.

High pressure sensor based on intensity-variation using polymer optical fiber.

Silica fiber under high pressure increases the risk of fiber breakage or permanent deformation, which may cause sensor failure due to mechanical strength limitations. High pressure can also induce birefringence in optical fiber. In this study, we present a simple design and low-cost high pressure sensor using polymer optical fiber (POF) based on the intensity-variation technique. A side-coupling mechanism in the sensor structure is adopted, which varies the intensity with applied pressure. Two POFs are twisted together to create a sensing region where the light is launched in the first fiber and measurement is taken from the second fiber. In sensing phenomena, cladding mode frustrated total internal reflection occurs when pressure increases. Silicone gel is used in the pressure chamber for sealing and preventing leakage. The sensor structure is able to detect high pressure in the MPa range, where we tested up to 4 MPa. For higher sensitivity, twisted and bend structure is analyzed, and sensitivity is achieved at about 432.21 nW/MPa. However, twisted helical structure is adopted to enhance sensing range which is about 50 cm. The proposed high-pressure sensor structure is easier to fabricate and has high stability because it doesn't require any destructive method as compared to other conventional methods.

Research on a novel composite structure Er³âº-doped DBR fiber laser with a π-phase shifted FBG.

A simple composite cavity structure Er³âº-doped fiber laser was proposed and demonstrated experimentally. The resonant cavity consists of a pair of uniform fiber Bragg gratings (FBGs) and a π-phase shifted FBG. By introducing the π-phase shifted FBG into the cavity as the selective wavelength component, it can increase the effective length of the laser cavity and suppress the multi-longitudinal modes simultaneously. The narrow linewidth of 900 Hz and low RIN of -95 dB/Hz were obtained. And the lasing wavelength was rather stable with the pump power changing. The SMRS was more than 67 dB. The results show that the proposed fiber laser has a good performance and considerable potential application for fiber sensor and optical communication.