Contactless vital signs monitoring based on few‐mode and multi‐core fibers

Few-mode and multi-core fibers are proposed and demonstrated for contactless vital signs monitoring in this paper.In-line optical fiber interferometers using few-mode and multi-core fibers are designed and offset splicing is utilized for mode excitation.Extinction ratio and insertion loss are analyzed experimentally under different offset distances.The fabricated in-line interferometers are packaged under the mattress to realize contactless vital signs signals collection.By using filtering techniques,both respiration and heartbeat signals can be recovered successfully,and respiration as well as heartbeat ratio are obtained.Mode excitation and interference are theoretically analyzed in few-mode fiber while curvature sensing experiments using multi-core fiber interferometer are performed to verify its excellent performance on vital signs monitoring.The successful demonstration on contactless vital signs monitoring makes few-mode and multi-core fibers promising candidates for healthcare applications.

High-Precision Vital Signs Detection Method Based on Spectrum Refinement and Extended DCMA

In this paper,the spectral estimation algorithm is extended to the detection of human vi-tal signs by mm-wave frequency modulated continuous wave(FMCW)radar,and a comprehensive algorithm based on spectrum refinement and the extended differentiate and cross multiply al-gorithm(DCMA)has been proposed.Firstly,the improved DFT algorithm is used to accurately obtain the distance window of human body.Secondly,phase ambiguity in phase extraction is avoided based on extended DCMA algorithm.Then,the spectrum range of refinement is determ-ined according to the peak position of the spectrum,and the respiratory and heartbeat frequency information is obtained by using chirp z-transform(CZT)algorithm to perform local spectrum re-finement.For verification,this paper has simulated the radar echo signal modulated by the simu-lated cardiopulmonary signal according to the proposed algorithm.By recovering the simulated car-diopulmonary signal,the high-precision respiratory and heartbeat frequency have been obtained.The results show that the proposed algorithm can effectively restore human breathing and heart-beat signals,and the relative error of frequency estimation is basically kept below 1.5%.

Dexmedetomidine-induced anesthesia in elderly patients undergoing hip replacement surgery

BACKGROUND A femoral neck fracture is a common and frequently reported issue in orthopedics, with a greater rate of incidence among the elderly. Due to their advanced age and the presence of some primary diseases, both anesthesia and surgery are increasingly difficult in elderly patients with a femoral neck fractures. In fact,general anesthesia can easily induce complications such as cognitive dysfunction,which is not conducive to postoperative recovery.AIM To analyze the efficacy of dexmedetomidine in inducing anesthesia for elderly patients undergoing hip replacement surgery.METHODS A total of 98 elderly patients undergoing hip replacement in our hospital from June 2020 to June 2021 were randomly divided into control group(49 cases) and observation group(49 cases). The control group was given general anesthesia, and the observation group was combined with dexmedetomidine for anesthesia on the basis of the control group. Both groups were observed until the patients were discharged. The vital signs, serum inflammatory factors and renal function indexes of the two groups were compared before, during and 6 h after operation.The postoperative recovery and adverse events of the two groups were statistically analyzed.RESULTS Compared with the mean arterial pressure of the two groups, the intraoperative and postoperative 6 h was higher than that before the operation, the intraoperative was lower than the postoperative 6 h(P < 0.05);the blood oxygen saturation of the two groups was higher than that before operation and 6 h after operation, and the observation group was higher than the control group 6 h after operation(P < 0.05). The heart rate of the two groups was lower during and 6 h after operation than that before operation, and higher at 6 h after operation than that during operation(P < 0.05).The levels of serum C-reactive protein, tumor necrosis factor-α, interleukin-1β and kidney injury molecule-1 in the two groups were higher during operation and 6 h after operation than those before operation(P < 0.05). The level of serum urea nitrogen in the two groups was higher than that before operation, and that in the observation group was lower than that in the control group(P < 0.05). During hospitalization, the first time of getting out of bed, recovery time of grade Ⅱ muscle strength, recovery time of grade Ⅲ muscle strength and hospitalization time in the observation group were shorter than those in the control group(P < 0.05).CONCLUSION Dexmedetomidine can effectively improve the vital signs of elderly patients undergoing hip replacement surgery, reduce the body’s inflammatory response and renal function damage, and promote postoperative recovery. Meanwhile, dexmedetomidine showcased a good safety profile and a good anesthetic outcome.

Clinical observation on the efficacy and safety of different doses of alfentanil for painless gastroscopy

Objective:To observe the Effective dose and safety of different doses of alfentanil combined with propofol in painless gastroscopy.Method:240 patients who underwent painless gastric examination from January 2021 to December 2021 were randomly divided into a control group and a different dose group of alfentanil(N1 group,N2 group,N3 group,N4 group,and N5 group,with injection doses of 5,6,7,8,and 10ug/kg,respectively)using a number table method,with 40 patients in each group.The control group was anesthetized with propofol injection,while different dosage groups of alfentanil were anesthetized with different doses of alfentanil combined with propofol.Evaluate the anesthesia effect after the examination is completed.Compare the heart rate(HR),systolic blood pressure(SBP),apnea time,incidence of intolerance to gastroscopy insertion,and adverse reactions in each group.Result:Compared with before administration,SBP and HR in all groups decreased before gastroscopy placement(P<0.01);At 1 minute after gastroscopy insertion,both SBP and HR in the control group increased(P<0.01),while SBP in the N3 and N4 groups decreased(P<0.01),while HR remained unchanged(P>0.05).Both SBP and HR in the N5 group decreased(P<0.01).Compared with before gastroscopy insertion,SBP and HR in the control group,N1,N2,and N3 groups increased 1 minute after gastroscopy insertion(P<0.01),while there was no significant change in SBP and HR in the N4 and N5 groups(P>0.05).The apnea time of different dosage groups of alfentanil was lower than that of the control group(P<0.01),and the apnea time of N5 group was higher than that of N1 group,N2 group,N3 group,and N4 group(P<0.01).There was no significant difference in the Incidence of intolerant reactions during gastroscopy insertion,cough reaction,retching reflex,swallowing reflex and limb movement reaction rate between the six groups(P>0.05);There was no statistically significant difference in the incidence of itching,nausea,vomiting,anxiety,dizziness,drowsiness,diarrhea,and constipation after painless gastroscopy examination among the six groups(P>0.05).Conclusion:The combination of 8ug/kg alfentanil and propofol has a definite anesthesia effect,stable respiratory and circulatory system,and low incidence of adverse reactions when used for painless gastroscopy.

Datamining and Its Applications

Artificial intelligence and machine learning are widely applied in all domain applications today,including noncontact vital sign monitoring,data mining and denoising,data analysis,and application as traffic simulation and green finance.We briefly introduce the noncontact vital sign monitoring using video data and the solutions to this problem supplied by Artificial intelligence and machine learning.Then,we present the five papers selected in the related areas for this journal issue.

Comparative Study on the Trans-Province Transfer of the Multiple Trauma Patients after Sichuan Earthquake

Background: Trans-province transfer of the patients has been successfully carried out and has greatly relieved the burden of the hospitals in Sichuan Province after Sichuan earthquake. The aim of the study was to retrospectively analyze the efficacy and feasibility of the trans-province transfer of the multiple trauma patients after Sichuan earthquake. Methods: A retrospective and descriptive analysis was conducted based on the medical records of the multiple trauma patients (ISS ≥ 16) transferred to the Grade 3A hospitals outside Sichuan province. The patients were divided into two groups based on the distance to Sichuan province, i.e., Group A (the seismic patients transferred to Chongqing) and Group B (the seismic patients transferred to the other provinces/ municipalities). A comparison was done in aspects of distance of transfer, time from injury to transfer, vital signs, the infection rates (at transfer and on discharge), injury severity and prognostic indices (cure rate, disability rate and mortality). Results: The distance between Chengdu and the other places was at a wide range of 313 - 1653 km, whereas the time from injury to transfer showed no statistical difference between groups (P > 0.05). There were no significant differences between both groups with respects to patient demographics, injury mechanism, time from injury to transfer, vital signs, infection rate and injury severity. The prognostic indices showed no significant difference, except for FIM scores (P < 0.05). Conclusions: The results of the study indicate that the different distance of the transfer of the multiple trauma patients does not aggravate the severity or deteriorate the prognosis, which proves that the medical supportive transfer system is acceptable, effective and worthy of further implementation in China, which may be ascribed to the advanced transportation system and high level of therapeutic capacity of the hospitals. In the meantime, attention should be paid to psychological intervention and functional rehabilitation during the treatment of the transferred seismic patients.

Pulse Generation and Compression Techniques for Microwave Electronics and Ultrafast Systems

Ultrabroadband systems and ultrafast electronics require the generation,transmission,and processing of high-quality ultrashort pulses rang-ing from nanoseconds(ns)to picoseconds(ps),which include well-established and emerging applications of time-domain reflectometry,arbitrary wave-form generation,sampling oscilloscopes,frequency synthesis,through-wall radar imaging,indoor communication,radar surveillance,and medical radar detection.Impulse radar advancements in industrial,scientific,and medical(ISM)domains are,for example,driven by ns-scale-defined ultrawideband(UWB)technologies.Nevertheless,the generation of ultrashort ps-scale pulses is highly desired to achieve unprecedented performances in all these ap-plications and future systems.However,due to the variety and applicability of different pulse generation and compression techniques,the selection of optimum or appropriate pulse generators and compressors is difficult for practitioners and users.To this end,this article aims to provide a comprehen-sive overview of ultrashort ns and ps pulse generation and compression techniques.The proposed and developed pulse generators available in the litera-ture and on the market,which are characterized by their corresponding pros and cons,are also explored.The theoretical analysis of pulse generation us-ing a nonlinear transmission line(NLTL)presented in the literature is briefly explained as well.Additionally,a holistic overview of these pulse genera-tors from the perspective of applications is given to describe their utilization in practical systems.All of these techniques are well summarized and com-pared in terms of fundamental pulse parameters,and research gaps in specified areas are highlighted.A thorough discussion of previous research work on various topologies and techniques is presented,and potential future directions for technical advancement are examined.

Design of a search and rescue terminal based on the dual-mode satellite and CDMA network

The current goal is to create a set of portable terminals with GPS/BD2 dual-mode satellite positioning, vital signs monitoring and wireless transmission functions. The terminal depends on an ARM processor to collect and combine data related to vital signs and GPS/BD2 location information, and sends the message to headquarters through the military CDMA network. It integrates multiple functions as a whole. The satellite positioning and wireless transmission capabilities are integrated into the motherboard, and the vital signs sensors used in the form of belts communicate with the board through Bluetooth. It can be adjusted according to the headquarters' instructions. This kind of device is of great practical significance for operations during disaster relief, search and rescue of the wounded in wartime, non-war military operations and other special circumstances.

Millimeter waves in medical applications:status and prospects

Millimeter waves are electromagnetic waves with wavelengths of 1–10 mm,which have characteristics of high frequency and short wavelength.They have gradually and widely been used in engineering and medical fields.We have identified studies related to millimeter waves in the biomedical field and summarized the biological effects of millimeter waves and their current status in medical applications.Finally,the shortcomings of existing studies and future developments were analyzed and discussed,with the aim of providing a reference for further research and development of millimeter waves in the medical field.