Effectiveness of one-to-one feedback methods of teaching with proper metered-dose inhaler technique and correcting errors in chronic obstructive lung disease patients

Objective:To determine the most common mistakes made during the use of a metered-dose inhaler(MDI),and the effect of the repeated trainings performed with demonstration method by providing one-to-one feedback on these mistakes.Methods:This is a quasi-experimental study with a control group.A total of 100 chronic obstructive pulmonary disease(COPD)patients(50 in the control group and 50 in the experimental group)were included in the research.“Patient Information Form(PIF)”(to determine the descriptive characteristics of patients)through the face-to-face interview method,using“MDI Skill Assessment Form”(MDISAF)(it is composed of 10 skill steps about the use of MDI)through observation method was used.Patients in both the groups were asked to use MDI and their abilities regarding use of MDI were assessed.Then in the intervention group,usage of MDI was explained by a nurse via demonstration and placebo MDI.Trainings were repeated on days 1,3,and 5 as from hospitalization of the patient.In the intervention group,three methods were used in this study:“face-to-face training,”“one-to-one,”and“with feedbacks and repeated.”Routine training regarding use of MDI was given by the nurses in the clinic to patients in the control group.The use of an MDI was assessed using MDISAF before training and after the training on the first,third and fifth days of hospitalization.On the seventh day,the last measurement was performed.Percentage,chi square,and mean were used to assess the data.Results:After repetitive training with one-to-one feedback,several differences between the groups in favor of the experimental group were found in 7 of the 10 skill levels of the MDI.There was a significant difference after“training”between the groups in the third,fourth,fifth,sixth,seventh,eighth and ninth MDI steps in posttest measurement(P<0.05).Evaluating the skills of the groups to use MDI from pretest to posttest,it was determined that while the intervention group made less mistakes in steps in which mistakes were made mostly,the control group continued to make mistakes.Conclusions:Inhaler technique intervention with repeated,face to face,and one-to-one feedback trainings can significantly enhance the MDI techniques in COPD patients.The patients in the intervention group made less mistakes during MDI application and their application skills improved.It may be asser ted that the training provided to the intervention group was effective for using the device correctly,while the training provided in the clinic for the control group was inadequate.

Effects of Signal Spectrum Bandwidth on Different PMD Compensation Feedback Methods

We compared efficiencies of different PMD compensation feedback methods against transmission signal bandwidth, including NRZ, RZ, CRZ format under various duty cycles. We found that the critical factor determining the efficiency of PMD compensation is not the modulation format, but the spectral bandwidth of the transmission signal.

Cooperative trajectory optimization of UAVs in approaching stage using feedback guidance methods

This paper mainly studies the problem of using UAVs to provide accurate remote target indication for hypersonic projectiles.Based on the optimal trajectory trends and feedback guidance methods,a new cooperative control algorithm is proposed to optimize trajectories of multi-UAVs for target tracking in approaching stage.Based on UAV kinematics and sensor performance models,optimal trajectory trends of UAVs are analyzed theoretically.Then,feedback guidance methods are proposed under the optimal observation trends of UAVs in the approaching target stage,producing trajectories with far less computational complexity and performance very close to the best-known trajectories.Next,the sufficient condition for the UAV to form the optimal observation configuration by the feedback guidance method is presented,which guarantees that the proposed method can optimize the observation trajectory of the UAV in approaching stage.Finally,the feedback guidance method is numerically simulated.Simulation results demonstrate that the estimation performance of the feedback guidance method is superior to the Lyapunov guidance vector field(LGVF)method and verify the effectiveness of the proposed method.Additionally,compared with the receding horizon optimization(RHO)method,the proposed method has the same optimization ability as the RHO method and better real-time performance.

A feedback control method for phase signal demodulation in fber-optic hydrophones

In the realm of acoustic signal detection,the identification of weak signals,particularly in the presence of negative signal-to-noise ratios,poses a significant challenge.This challenge is further heightened when signals are acquired through fiber-optic hydrophones,as these signals often lack physical significance and resist clear systematic modeling.Conventional processing methods,e.g.,low-pass filter(LPF),require a thorough understanding of the effective signal bandwidth for noise reduction,and may introduce undesirable time lags.This paper introduces an innovative feedback control method with dual Kalman filters for the demodulation of phase signals with noises in fiber-optic hydrophones.A mathematical model of the closed-loop system is established to guide the design of the feedback control,aiming to achieve a balance with the input phase signal.The dual Kalman filters are instrumental in mitigating the effects of signal noise,observation noise,and control execution noise,thereby enabling precise estimation for the input phase signals.The effectiveness of this feedback control method is demonstrated through examples,showcasing the restoration of low-noise signals,negative signal-to-noise ratio signals,and multi-frequency signals.This research contributes to the technical advancement of high-performance devices,including fiber-optic hydrophones and phase-locked amplifiers.

An improved car-following model with consideration of the lateral effect and its feedback control research

A car-following model is presented, in which the effects of non-motor vehicles on adjacent lanes are taken into ac- count. A control signal including the velocity differences between the following vehicle and the target vehicle is introduced according to the feedback control theory. The stability condition for the new model is derived. Numerical simulation is used to demonstrate the advantage of the new model including the control signal; the results are consistent with the analytical ones

Time-delayed feedback control optimization for quasi linear systems under random excitations

A strategy for time-delayed feedback control optimization of quasi linear systems with random excitation is proposed. First, the stochastic averaging method is used to reduce the dimension of the state space and to derive the stationary response of the system. Secondly, the control law is assumed to be velocity feedback control with time delay and the unknown control gains are determined by the performance indices. The response of the controlled system is predicted through solving the Fokker-Plank-Kolmogorov equation associated with the averaged Ito equation. Finally, numerical examples are used to illustrate the proposed control method, and the numerical results are confirmed by Monte Carlo simulation .

A sensitive method of determining optic axis azimuth based on laser feedback

A sensitive method to determine the optic axis azimuth of the birefringence element is presented, which is based on laser feedback. The phase difference between the two intensities in birefringence feedback changes with the angle between the optic axis of the birefringence element and laser original polarization. The phase difference is highly sensitive to the relative position of the optic axis and the laser original polarization. This method is used to highly precisely determine the optic axis azimuth, and is able to distinguish between the fast axis and the slow axis of the birefringence element. Theoretical analysis and experimental results are both demonstrated.

Effect of feedback health education on postoperative rehabilitation of patients with lumbar disc herniation: a cluster randomised trials

Aims and objective:A theoretical model based on guided postoperative rehabilitation with feedback was developed for patients with lumbar intervertebral disc protrusion to explore the effects of feedback-based health education.Patients were assessed in terms of disease knowledge,general self-efficacy,medical behaviour,and the Oswestry disability index(ODI).During postoperative rehabilitation,nursing staff provided health education regarding lumbar intervertebral disc protrusion.Design:The CONSORT 2010 statement extension for cluster randomized trials checklist(Campbell et al.,2012)was used to guide reporting outcomes(File S1).Methods:The methods were based on previous research on the feedback method of health education.A cluster randomized controlled trial design was used.From March 2019 to January 2020,patients who underwent spinal surgery at a first-class tertiary hospital were enrolled,and 76 met the inclusion criteria for lumbar disc disease(lumbar disc herniation,LDH).Patients were divided into an experimental group and a control group,with 38 patients in each group.Feedback-based health education was conducted for the experimental group,and routine health education was provided for the control group.Disease knowledge,general self-efficacy,compliance behaviour,and ODI scores were compared between the two groups.The intervention effect was compared between groups by means of t tests.SPSS 23.0 was used for statistical analysis,and P<0.05 was considered statistically significant.The research was reported according to CONSORT statement.Results:1.Comparison of baseline data between the two groups before the intervention.Before the intervention,there was no statistically significant difference between the two groups in terms of general demographic data,disease-related data,disease knowledge,general self-efficacy,compliance behaviour,or ODI(P>0.05).2.Comparison of relevant indicators between the two groups of patients before and after the intervention.(1)One,four and 12 weeks after surgery,the disease knowledge,general self-efficacy and postoperative compliance behaviour of the experimental group were significantly higher than those of the control group(P<0.05).(2)At 1,4 and 12 weeks after surgery,the ODI of the experimental group was significantly lower than that of the control group(P<0.05).Conclusions:Feedback-based health education is conducive to improving disease knowledge,general self-efficacy and compliance behaviour and reducing ODI scores in patients with LDH.Relevance to clinical practice:This study provides nurses worldwide with a reference for health education during postoperative rehabilitation for lumbar disc herniation.

Leader-following coordination of multiple UUVs formation under two independent topologies and time-varying delays

The new method which uses the consensus algorithm to solve the coordinate control problems of multiple unmanned underwater vehicles （multi-UUVs） formation in the case of leader-following is adapted. As the communication between the UUVs is difficult and it is easy to be interfered under the water, time delay is assumed to be time-varying during the members communicate with each other. Meanwhile, the state feedback linearization method is used to transfer the nonlinear and coupling model of UUV into double-integrator dynamic. With this simplified double-integrator math model, the UUV formation coordinate control is regarded as consensus problem with time-varying communication delays. In addition, the position and velocity topologies are adapted to reduce the data volume in each data packet which is sent between members in formation. With two independent topologies designed, two cases of communication delay which are same and different are considered and the sufficient conditions are proposed and analyzed. The stability of the multi-UUVs formation is proven by using Lyapunov-Razumilkhin theorem. Finally, the simulation results are presented to confirm and illustrate the theoretical results.

Control and Stabilization of Chaotic System Based on Linear Feedback Control Method

In this paper, two kinds of chaotic systems are controlled respectively with and without time-delay to eliminate their chaotic behaviors. First of all, according to the first-order approximation method and the stabilization condition of the linear system, one linear feedback controller is structured to control the chaotic system without time-delay, its chaotic behavior is eliminated and stabilized to its equilibrium. After that, based on the first-order approximation method, the Lyapunov stability theorem, and the matrix inequality theory, the other linear feedback controller is structured to control the chaotic system with time-delay and make it stabilized at its equilibrium. Finally, two numerical examples are given to illustrate the correctness and effectiveness of the two linear feedback controllers.

Method for in situ calibration of multiple feedback interferometers

A method is presented for in situ resolution calibration of multiple feedback interferometers(MFIs) using two lasers with di?erent feedback levels simultaneously. The laser with weak optical feedback level generates half-wavelength optical fringes, whereas the laser with strong multiple feedback level generates optical nanofringes. By using this method, the number of displaced optical nano-fringes can be easily counted, and the resolution of the MFIs can be accurately determined. The integrated MFIs can be used to measure displacements and calibrate other displacement sensors.

Design of Non-rational MIMO Feedback Systems with Inputs and Outputs Satisfying Certain Bounding Conditions by Using Rational Approximants

When a feedback system has components described by non-rational transfer functions, a standard practice in designing such a system is to replace the non-rational functions with rational approximants and then carry out the design with the approximants by means of a method that copes with rational systems. In order to ensure that the design carried out with the approximants still provides satisfactory results for the original system, a criterion of approximation should be explicitly taken into account in the design formulation. This paper derives such a criterion for multi-input multi-output（MIMO） feedback systems whose design objective is to ensure that the absolute values of every error and every controller output components always stay within prescribed bounds whenever the inputs satisfy certain bounding conditions. The obtained criterion generalizes a known result which was derived for single-input single-output（SISO） systems; furthermore, for a given rational approximant matrix, it is expressed as a set of inequalities that can be solved in practice. Finally, a controller for a binary distillation column is designed by using the criterion in conjunction with the method of inequalities. The numerical results clearly demonstrate that the usefulness of the criterion in obtaining a design solution for the original system.