Objectives:The objective of the study was to explore the impact of auditory stimulation protocol on auditory response in cerebrovascular stroke(CVS)patients.Materials and Methods:A pre-posttest nonequivalent control g...Objectives:The objective of the study was to explore the impact of auditory stimulation protocol on auditory response in cerebrovascular stroke(CVS)patients.Materials and Methods:A pre-posttest nonequivalent control group quasi-experimental study was conducted at Al Mainal Hospital at Al Kars Einy Hospital,Cairo University,among 60 CVS patients,and the sample was randomly assigned through a coin to allocate subjects to study or control group(30 for each group).Auditory stimulation techniques were applied three times per week for the study group for two consecutive weeks.Patients in the control group received only routine hospital care during the study period.The Glasgow Coma Scale(GCS)score for assessing the neurological function and level of arousal and the auditory subscale score of Western Neuro Sensory Stimulation Profile(WNSSP)for assessing auditory response were recorded and compared between the two groups before and after the intervention.Results:There were statistically significant differences between the study group and the control group regarding third reading of GCS score(11.5±0.3 vs.10.6±0.9,t=4.676,P=0.000).The scores of all auditory subscales of WNSSP in the study groups increased after implementing the auditory stimulation protocol(P<0.05).Conclusion:Utilizing the auditory stimulation protocol by nurse proves to be an effective method for enhancing hearing responses in individuals with CVS.展开更多
The majority of nonlinear stochastic systems can be expressed as the quasi-Hamiltonian systems in science and engineering. Moreover, the corresponding Hamiltonian system offers two concepts of integrability and resona...The majority of nonlinear stochastic systems can be expressed as the quasi-Hamiltonian systems in science and engineering. Moreover, the corresponding Hamiltonian system offers two concepts of integrability and resonance that can fully describe the global relationship among the degrees-of-freedom(DOFs) of the system. In this work, an effective and promising approximate semi-analytical method is proposed for the steady-state response of multi-dimensional quasi-Hamiltonian systems. To be specific, the trial solution of the reduced Fokker–Plank–Kolmogorov(FPK) equation is obtained by using radial basis function(RBF) neural networks. Then, the residual generated by substituting the trial solution into the reduced FPK equation is considered, and a loss function is constructed by combining random sampling technique. The unknown weight coefficients are optimized by minimizing the loss function through the Lagrange multiplier method. Moreover, an efficient sampling strategy is employed to promote the implementation of algorithms. Finally, two numerical examples are studied in detail, and all the semi-analytical solutions are compared with Monte Carlo simulations(MCS) results. The results indicate that the complex nonlinear dynamic features of the system response can be captured through the proposed scheme accurately.展开更多
The stable steady-state periodic responses of a belt-drive system with a one-way clutch are studied. For the first time, the dynamical system is investigated under dual excitations. The system is simultaneously excite...The stable steady-state periodic responses of a belt-drive system with a one-way clutch are studied. For the first time, the dynamical system is investigated under dual excitations. The system is simultaneously excited by the firing pulsations of the engine and the harmonic motion of the foundation. Nonlinear discrete-continuous equations are derived for coupling the transverse vibration of the belt spans and the rotations of the driving and driven pulleys and the accessory pulley. The nonlinear dynamics is studied under equal and multiple relations between the frequency of the fir- ing pulsations and the frequency of the foundation motion. Furthermore, translating belt spans are modeled as axially moving strings. A set of nonlinear piecewise ordinary differ- ential equations is achieved by using the Galerkin truncation. Under various relations between the excitation frequencies, the time histories of the dynamical system are numerically simulated based on the time discretization method. Further- more, the stable steady-state periodic response curves are calculated based on the frequency sweep. Moreover, the convergence of the Galerkin truncation is examined. Numer- ical results demonstrate that the one-way clutch reduces the resonance amplitude of the rotations of the driven pul- ley and the accessory pulley. On the other hand, numerical examples prove that the resonance areas of the belt spans are decreased by eliminating the torque-transmitting in the opposite direction. With the increasing amplitude of the foun- dation excitation, the damping effect of the one-way clutch will be reduced. Furthermore, as the amplitude of the firing pulsations of the engine increases, the jumping phenomena in steady-state response curves of the belt-drive system with or without a one-way clutch both occur.展开更多
The steady-state transverse vibration of an axially moving string with geometric nonlinearity was investigated. The transport speed was assumed to be a constant mean speed with small harmonic variations. The nonlinear...The steady-state transverse vibration of an axially moving string with geometric nonlinearity was investigated. The transport speed was assumed to be a constant mean speed with small harmonic variations. The nonlinear partial-differential equation that governs the transverse vibration of the string was derived by use of the Hamilton principle. The method of multiple scales was applied directly to the equation. The solvability condition of eliminating the secular terms was established. Closed form solutions for the amplitude and the existence conditions of nontrivial steady-state response of the two-to-one parametric resonance were obtained. Some numerical examples showing effects of the mean transport speed, the amplitude and the frequency of speed variation were presented. The Liapunov linearized stability theory was employed to derive the instability conditions of the trivial solution and the nontrivial solutions for the two-to-one parametric resonance. Some numerical examples highlighting influences of the related parameters on the instability conditions were presented.展开更多
BACKGROUND: Auditory steady-state evoked response (ASSR) is one of the new objective electrophysiological methods to test hearing in infants. It can provide a reliable and complete audiogram with specific frequency to...BACKGROUND: Auditory steady-state evoked response (ASSR) is one of the new objective electrophysiological methods to test hearing in infants. It can provide a reliable and complete audiogram with specific frequency to help the hearing diagnosis and rehabilitation of hearing and languaging following auditory screening. OBJECTIVE: To compare the response threshold of ASSR with auditory threshold of visual reinforcement audiometry (VRA) in infants failed in the hearing screening for investigating their hearing loss. DESIGN: A comparative observation. SETTINGS: Maternal and child health care hospitals of Guangdong province, Shunde city, Nanhai city and Huadu district. PARTICIPANTS: Totally 321 infants of 0-3 years undergoing ASSR test were selected from the Hearing Center of Guangdong Maternal and Child Health Care Hospital from January 2002 to December 2004. Informed consents were obtained from their guardians. There were 193 cases (60.2%) of 0-6 months, 31 cases (9.7%) of 7-12 months, 17 cases (5.3%) of 13-18 months, 14 cases (4.4%) of 19-24 months, 33 cases of 25-30 months, and 33 cases (10.2%) of 31-36 months. METHODS: ① The 321 infants failed in the hearing screening were tested under sleeping status, the ranges of response threshold distribution in ASSR of different frequencies were analyzed in each age group. ② The infants above 2 years old were also tested with VRA, and their response thresholds were compared between VRA and ASSR. ③ Evaluative standards: The response threshold was < 30 dB for normal hearing, 31-50 dB for mild hearing loss, 51-70 dB for moderate hearing loss, 71-90 dB for severe hearing loss, and > 91 dB for extremely severe hearing loss. MAIN OUTCOME MEASURES: ① ASSR results of the infants failed in the screening; ② Proportion of cases of each response threshold in each age group; ③ Comparison of ASSR response thresholds and VRA auditory thresholds in the infants of 2-3 years old. RESULTS: ①The response threshold was < 30 dB in 47.4% of the 321 infants failed in the initial hearing screening and secondary screening after 42 days. ② Severe to extremely severe hearing loss was detected in only 16 cases (8.3%) of the 193 infants of 0-6 months, in 9 cases (27.3%) of the 33 infants of 25-30 months, and 13 cases (39.4%) of the 33 infants of 31-36 months. Of the 193 infants of 0-6 months old who failed in the initial screening and the second screening after 42 days, the ASSR auditory threshold was < 30 dB in 97 cases (50.26%), 31-50 dB in 63 cases (32.6%), 51-70 dB in 17 cases (8.8%), 71-90 dB in 7 cases (3.6%), and > 91 dB in 9 cases (4.7%). ③ Among the 321 infants failed in the screening, the auditory threshold in the 6 age groups was < 30 dB in 47.4%, 31-50 dB in 27.1%, 51-70 dB in 8.4%, 71-90 dB in 6.2%, and > 91 dB in 10.9%. ④ The difference between ASSR response threshold and VRA auditory thresholds was 6-18 dB in the normal hearing group, mild and moderate hearing loss groups, and there was high correlation between them. The difference of ASSR and VRA thresholds was less than 5 dB between extremely severe and severe hearing loss groups, 5-13 dB between extremely severe and moderate-to-severe hearing loss groups (P < 0.05), and there was no significant differences between severe and moderate-to-severe hearing loss groups (P > 0.05). CONCLUSION: ① The hearing was normal in about half of the infants, although they failed in the primary screening and secondary screening. ② The proportion of the severity of hearing loss was increased along with aging. ③ Mild and moderate hearing losses are dominant in infants. ④ ASSR is reliable to evaluate the hearing of infants.展开更多
This exploratory study examined the short-term reliability of cortical auditory evoked responses recorded from patients undergoing whole-head scalp elec-troencephalography (EEG) monitoring to assess their candidacy fo...This exploratory study examined the short-term reliability of cortical auditory evoked responses recorded from patients undergoing whole-head scalp elec-troencephalography (EEG) monitoring to assess their candidacy for surgical treatment of intractable focal seizures. Participants were 26 patients with either left-sided (N = 13) or right-sided focal epilepsy admitted to the hospital for continuous scalp EEG monitoring for possible epilepsy surgery planning. Cortical auditory evoked responses were recorded over multiple days from scalp EEG electrodes using tones presented binaurally in a passive oddball paradigm. Test-retest intervals were 1 - 6 days (mean 2 days). Test-retest reproducibility of the auditory N1 response was assessed by paired t-test (latency) and cross-correlation analysis (amplitude and latency). Within-patient comparisons of test-retest auditory N1 peak latencies revealed no significant differences. The cross-correlation coefficient indicated high test-retest reproducibility of the N1 waveform (rcc = 0.88). Seizure lateralization was not associated with asymmetries in N1 latencies or amplitudes. An N1 amplitude asymmetry (right > left) in patients with focal seizures originating from the left hemisphere was initially observed, but disappeared when patients with prior resections were excluded, suggesting that reduced left hemisphere tissue volume may account for the smaller N1 amplitudes. Test-retest reliability of cortical auditory evoked responses was unexpectedly high in patients with focal epilepsy regardless of seizure lateralization or localization. These findings challenge the view that neural responses are intrinsically unstable (unreliable) in patients with seizures.展开更多
Spherical-symmetric steady-state response problem of piezoelectric spherical shell in the absence of body force and free charges is discussed. The steady-state response solutions of mechanical displacement, stresses, ...Spherical-symmetric steady-state response problem of piezoelectric spherical shell in the absence of body force and free charges is discussed. The steady-state response solutions of mechanical displacement, stresses, strains, potential and electric displacement were derived Sram constitutive relations, geometric and motion equations for the piezoelectric medium under external excitation (i.e. applied surface traction and potential) in spherical coordinate system. As an application of the? general solutions, the problem of an elastic spherical shell with piezoelectric actuator and sensor layers was solved. The results could provide good theoretical basis for the spherical-symmetric dynamic control problem of piezoelectric intelligent structure. Furthermore, the solutions can serve as reference for the research of general dynamic control problem.展开更多
The auditory brainstern responses(ABR)and middle latency responses(MLR)were recorded in 24 normal mice with a 7S11A processor,and the normalparameters of ABR and MLR obtained.The results showed that the ABR of mice we...The auditory brainstern responses(ABR)and middle latency responses(MLR)were recorded in 24 normal mice with a 7S11A processor,and the normalparameters of ABR and MLR obtained.The results showed that the ABR of mice werecomposed of 6 waves,waves Ⅰ to Ⅵ.The mean threshold was 35.12±8.03 dB ,whichwas significantly different from the 22.63 dB of ABR found in guinea pigs.Thelatency of ABR waves Ⅰ to Ⅵizn the mice was found to be 1.30±8.03 ms ;2.02±0.24ms ;2.90±0.27 ms ;3.80±0.24 ms ;4.87±0.42 ms and 5.83±0.40 ms respectively.Nosex or strain differences were found.The MLR waveform of the mice were similar tothose of human and the latency was found to be P0 3.94±1.76 ms;P8.38±1.57ms;Na 14.98±2.54 ms;Pa 24.56±3.15 ms rcspectively.It is suggested that mice can beused for hearing research.Since the Na and Pa waves of MLR were unstable under anes-thesia,testing conditions for determining MLR in mice need further study.展开更多
Objective To analyze the characteristics of auditory brainstem response (ABR) in presbycusis patients el-der than 90 years. Methods Fourteen presbycusis patients elder than 90 years (presbycusis group, 91.1.4 ± 1...Objective To analyze the characteristics of auditory brainstem response (ABR) in presbycusis patients el-der than 90 years. Methods Fourteen presbycusis patients elder than 90 years (presbycusis group, 91.1.4 ± 1.3 years, 26 ears) and 9 normal-hearing young adults (control group, 22.7 ± 1.2 years, 18 ears) participated in the study. Alternative click-evoked ABRs were recorded in both groups. The peak latency (PL) of peak I,Ⅲ, and V, and the inter-peak latency (IPI) of I-Ⅲ,Ⅲ-V, and I-V were compared between groups. Results In elder presbycusis patients, the occurrence rate of peak I andⅢwere both 76.9%, and that of peak V was 84.6%. In presbycusis group, the peak latencies of I, Ⅲ, V were significantly longer than that of control group (P<0.001). There was no significant difference between groups in the IPI of peak I-IⅢ (P=0.298, peakⅢ-V (P=0.254) and peak I-V (P=0.364). Conclusions Auditory brainstem responses in presbycusis pa-tients elder than 90 years showed worse wave differentiation.展开更多
Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate. Methods CM, CAP, DPOAE, and ABR were recorded as indicators of cochlear f...Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate. Methods CM, CAP, DPOAE, and ABR were recorded as indicators of cochlear functions during whole cochlear perfusion. The morphology of the cochlea was studied via transmission electron microscopy. Results There were no significant changes in DPOAE amplitude before and after glutamate perfusion. CM I/O function remained nonlinear during perfusion. ABR latencies were delayed following glutamate perfusion. The average CAP threshold was elevated 35 dB SPL following glutamate perfusion.. The OHCs appeared normal, but the IHCs and afferent dendrites showed cytoplasmic blebs after glutamate perfusion. Conclusions While being a primary amino acid neurotransmitter at the synapses between hair cells and spiral ganglion neurons, excessive glutamate is neurotoxic and can destroy IHCs and spiral ganglion neurons. The technique used in this study can also be used to build an animal model of auditory neuropathy.展开更多
This paper presents a closed-form algorithm for the steady-state response of elastic mecha-nisms. Based on an analytic expression of the initial conditions, the steady-state response can beobtained by just one cycle o...This paper presents a closed-form algorithm for the steady-state response of elastic mecha-nisms. Based on an analytic expression of the initial conditions, the steady-state response can beobtained by just one cycle of integration, thus the algorithm is of high efficiency. The algorithm isthen verified by comparing the computational results with the previously published experimental re-sults.展开更多
To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews(30 ears) were stimulated with clicks and ton...To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews(30 ears) were stimulated with clicks and tone-pips at 11 different frequencies from 1 to 60 kHz. The ABR waves were recorded and analyzed. The ABR consisted of five to seven positive waves in the first 10 ms after a click stimulus, and the average hearing threshold of component III was 27.86 ± 3.78 dB SPL. Wave III was the largest and most clear. The ABR threshold was related to the tone-pip sitmulus by a "U" shaped curve. The sensitive frequency was approximately 8 kHz in tree shrews. The latencies systematically decreased with increasing stimulus frequencies. The ABR amplitudes of wave III increased as the sound pressure level increased. All of these results provide an empirical basis for future studies of hearing diseases in tree shrews.展开更多
The auditory steady state response (ASSR) may reflect activity from different regions of the brain, depending on the modulation frequency used. In general, responses induced by low rates (_〈40 Hz) emanate mostly ...The auditory steady state response (ASSR) may reflect activity from different regions of the brain, depending on the modulation frequency used. In general, responses induced by low rates (_〈40 Hz) emanate mostly from central structures of the brain, and responses from high rates (〉80 Hz) emanate mostly from the peripheral auditory nerve or brainstem structures. Besides, it was reported that the gamma band ASSR (30-90 Hz) played an important role in working memory, speech understanding and recognition. This paper investigated the 40 Hz ASSR evoked by modulated speech and reversed speech. The speech was Chinese phrase voice, and the noise-like reversed speech was obtained by temporally reversing the speech. Both auditory stimuli were modulated with a frequency of 40 Hz. Ten healthy subjects and 5 patients with hallucination symptom participated in the experiment. Results showed re- duction in left auditory cortex response when healthy subjects listened to the reversed speech compared with the speech. In contrast, when the patients who experienced auditory hallucinations listened to the reversed speech, the auditory cortex of left hemispheric responded more actively. The ASSR results were consistent with the behavior results of patients. Therefore, the gamma band ASSR is expected to be helpful for rapid and objective diagnosis of hallucination in clinic.展开更多
The auditory brainstem response (ABR) was measured for 90 cars of norml gui-nea pigs,from which the mean latency,amplitude and recognition of waves were obtain-ded.The waves were classified into six types,with wave Ⅲ...The auditory brainstem response (ABR) was measured for 90 cars of norml gui-nea pigs,from which the mean latency,amplitude and recognition of waves were obtain-ded.The waves were classified into six types,with wave Ⅲ as the main wave which ac-counted for 77.1% of all the waves.The frequency domain of each type was analysed bymeans of digital filtering and auto-regressive (AR)estimation.The main frequency com-position of ABR in the guinea pigs was restricted within 1600 Hz,in which there werethree peaks at AR spectrum,the mean value of the peaks being 107.33 Hz,566.67 Hzand 1076 Hz respectively.The AR spectrograms of all types waves were very similar toeach other.展开更多
Objective To study local inflammatory response after implantation of hydroxyapatite synthetic ossicular prosthesis. Methods Hydroxyapatite granules were implanted in the bulla in 32 rats. Sham surgical procedures were...Objective To study local inflammatory response after implantation of hydroxyapatite synthetic ossicular prosthesis. Methods Hydroxyapatite granules were implanted in the bulla in 32 rats. Sham surgical procedures were performed in 10 rats as the control. Animals were sacrificed at 1 to 300 days after surgery. Bulla sections, stained with HE and Mallory’s azan, were examined for numbers and percentages of various inflammatory cell types. Results Slightly more inflammatory reaction was seen in animals with the implant than in the controls, mostly during the early stage following the implantation procedure. Few inflammatory cells were observed at later times. There were satisfactory fibrosis in both implanted and control ears. Conclusion The results indicate that hydroxyapatite synthetic prosthesis is a biocompatible implantation material in the middle ear. Nonetheless, the presence of inflammatory reaction immediately following implantation implies that control of infection is important in the early times after the implantation procedure.展开更多
The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process ...The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process employed in its study and the clinical experience required for its analysis. When analyzing the ABR, clinicians are often interested in the identification of ABR signal components referred to as Jewett waves. In particular, the detection and study of the time when these waves occur (i.e., the wave latency) is a practical tool for the diagnosis of disorders affecting the auditory system. In this context, the aim of this research is to compare ABR manual/visual analysis provided by different examiners. Methods: The ABR data were collected from 10 normal-hearing subjects (5 men and 5 women, from 20 to 52 years). A total of 160 data samples were analyzed and a pair- wise comparison between four distinct examiners was executed. We carried out a statistical study aiming to identify significant differences between assessments provided by the examiners. For this, we used Linear Regression in conjunction with Bootstrap, as a method for evaluating the relation between the responses given by the examiners. Results: The analysis suggests agreement among examiners however reveals differences between assessments of the variability of the waves. We quantified the magnitude of the obtained wave latency differences and 18% of the investigated waves presented substantial differences (large and moderate) and of these 3.79% were considered not acceptable for the clinical practice. Conclusions: Our results characterize the variability of the manual analysis of ABR data and the necessity of establishing unified standards and protocols for the analysis of these data. These results may also contribute to the validation and development of automatic systems that are employed in the early diagnosis of hearing loss.展开更多
目的探讨多种听力学检测方法在听性脑干反应(ABR)最大输出未引出患儿的听力学诊断中的应用价值。方法回顾性分析69例(138耳)ABR最大强度未引出患儿的临床资料,年龄42天到5岁,平均1岁6个月,鼓室导抗图均为A型或正向单峰,声反射均未引出,...目的探讨多种听力学检测方法在听性脑干反应(ABR)最大输出未引出患儿的听力学诊断中的应用价值。方法回顾性分析69例(138耳)ABR最大强度未引出患儿的临床资料,年龄42天到5岁,平均1岁6个月,鼓室导抗图均为A型或正向单峰,声反射均未引出,影像学检查内耳无畸形。69例患儿均进行ABR、耳蜗微音电位(CM)、畸变产物耳声发射(DPOAE)和听性稳态反应(ASSR)测试。结果69例138耳中,8例16耳(11.59%)记录到CM,其中10耳(7.25%)记录到DPOAE,0.5、1、2、4 kHz ASSR反应阈值分别为83.2±13.1、82.9±13.0、75.3±12.4、63.1±9.1 dB nHL,结合其他检查结果诊断为听神经病。余61例(122耳)CM和DPOAE均未引出,0.5、1、2、4 kHz的ASSR引出率分别为82.3%、81.9%、76.9%、60.2%,其中20耳ASSR各频率均未引出,102耳至少一个频率引出,0.5、1、2、4 kHz ASSR反应阈分别为93.2±6.1、99.8±7.0、105.4±5.4、108.2±9.8 dB nHL,诊断为极重度感音神经性聋。结论对于ABR最大输出强度未引出的患儿,CM和/或DPOAE引出且ASSR各频率反应阈低于感音神经性聋患儿,有助于听神经病的诊断;CM和DPOAE均未引出有助于极重度感音神经性聋的诊断,ASSR测试有助于评估其残余听力。展开更多
文摘Objectives:The objective of the study was to explore the impact of auditory stimulation protocol on auditory response in cerebrovascular stroke(CVS)patients.Materials and Methods:A pre-posttest nonequivalent control group quasi-experimental study was conducted at Al Mainal Hospital at Al Kars Einy Hospital,Cairo University,among 60 CVS patients,and the sample was randomly assigned through a coin to allocate subjects to study or control group(30 for each group).Auditory stimulation techniques were applied three times per week for the study group for two consecutive weeks.Patients in the control group received only routine hospital care during the study period.The Glasgow Coma Scale(GCS)score for assessing the neurological function and level of arousal and the auditory subscale score of Western Neuro Sensory Stimulation Profile(WNSSP)for assessing auditory response were recorded and compared between the two groups before and after the intervention.Results:There were statistically significant differences between the study group and the control group regarding third reading of GCS score(11.5±0.3 vs.10.6±0.9,t=4.676,P=0.000).The scores of all auditory subscales of WNSSP in the study groups increased after implementing the auditory stimulation protocol(P<0.05).Conclusion:Utilizing the auditory stimulation protocol by nurse proves to be an effective method for enhancing hearing responses in individuals with CVS.
基金Project supported by the National Natural Science Foundation of China (Grant No. 12072118)the Natural Science Funds for Distinguished Young Scholar of the Fujian Province, China (Grant No. 2021J06024)the Project for Youth Innovation Fund of Xiamen, China (Grant No. 3502Z20206005)。
文摘The majority of nonlinear stochastic systems can be expressed as the quasi-Hamiltonian systems in science and engineering. Moreover, the corresponding Hamiltonian system offers two concepts of integrability and resonance that can fully describe the global relationship among the degrees-of-freedom(DOFs) of the system. In this work, an effective and promising approximate semi-analytical method is proposed for the steady-state response of multi-dimensional quasi-Hamiltonian systems. To be specific, the trial solution of the reduced Fokker–Plank–Kolmogorov(FPK) equation is obtained by using radial basis function(RBF) neural networks. Then, the residual generated by substituting the trial solution into the reduced FPK equation is considered, and a loss function is constructed by combining random sampling technique. The unknown weight coefficients are optimized by minimizing the loss function through the Lagrange multiplier method. Moreover, an efficient sampling strategy is employed to promote the implementation of algorithms. Finally, two numerical examples are studied in detail, and all the semi-analytical solutions are compared with Monte Carlo simulations(MCS) results. The results indicate that the complex nonlinear dynamic features of the system response can be captured through the proposed scheme accurately.
基金project was supported by the State Key Program of the National Natural Science Foundation of China(Grant 11232009)the National Natural Science Foundation of China(Grants 11372171,11422214)
文摘The stable steady-state periodic responses of a belt-drive system with a one-way clutch are studied. For the first time, the dynamical system is investigated under dual excitations. The system is simultaneously excited by the firing pulsations of the engine and the harmonic motion of the foundation. Nonlinear discrete-continuous equations are derived for coupling the transverse vibration of the belt spans and the rotations of the driving and driven pulleys and the accessory pulley. The nonlinear dynamics is studied under equal and multiple relations between the frequency of the fir- ing pulsations and the frequency of the foundation motion. Furthermore, translating belt spans are modeled as axially moving strings. A set of nonlinear piecewise ordinary differ- ential equations is achieved by using the Galerkin truncation. Under various relations between the excitation frequencies, the time histories of the dynamical system are numerically simulated based on the time discretization method. Further- more, the stable steady-state periodic response curves are calculated based on the frequency sweep. Moreover, the convergence of the Galerkin truncation is examined. Numer- ical results demonstrate that the one-way clutch reduces the resonance amplitude of the rotations of the driven pul- ley and the accessory pulley. On the other hand, numerical examples prove that the resonance areas of the belt spans are decreased by eliminating the torque-transmitting in the opposite direction. With the increasing amplitude of the foun- dation excitation, the damping effect of the one-way clutch will be reduced. Furthermore, as the amplitude of the firing pulsations of the engine increases, the jumping phenomena in steady-state response curves of the belt-drive system with or without a one-way clutch both occur.
文摘The steady-state transverse vibration of an axially moving string with geometric nonlinearity was investigated. The transport speed was assumed to be a constant mean speed with small harmonic variations. The nonlinear partial-differential equation that governs the transverse vibration of the string was derived by use of the Hamilton principle. The method of multiple scales was applied directly to the equation. The solvability condition of eliminating the secular terms was established. Closed form solutions for the amplitude and the existence conditions of nontrivial steady-state response of the two-to-one parametric resonance were obtained. Some numerical examples showing effects of the mean transport speed, the amplitude and the frequency of speed variation were presented. The Liapunov linearized stability theory was employed to derive the instability conditions of the trivial solution and the nontrivial solutions for the two-to-one parametric resonance. Some numerical examples highlighting influences of the related parameters on the instability conditions were presented.
基金a grant from Medical Scientific Research Foundation of G uangdong Bureau of Hygiene,No.W STJJ2001111044082219581224001
文摘BACKGROUND: Auditory steady-state evoked response (ASSR) is one of the new objective electrophysiological methods to test hearing in infants. It can provide a reliable and complete audiogram with specific frequency to help the hearing diagnosis and rehabilitation of hearing and languaging following auditory screening. OBJECTIVE: To compare the response threshold of ASSR with auditory threshold of visual reinforcement audiometry (VRA) in infants failed in the hearing screening for investigating their hearing loss. DESIGN: A comparative observation. SETTINGS: Maternal and child health care hospitals of Guangdong province, Shunde city, Nanhai city and Huadu district. PARTICIPANTS: Totally 321 infants of 0-3 years undergoing ASSR test were selected from the Hearing Center of Guangdong Maternal and Child Health Care Hospital from January 2002 to December 2004. Informed consents were obtained from their guardians. There were 193 cases (60.2%) of 0-6 months, 31 cases (9.7%) of 7-12 months, 17 cases (5.3%) of 13-18 months, 14 cases (4.4%) of 19-24 months, 33 cases of 25-30 months, and 33 cases (10.2%) of 31-36 months. METHODS: ① The 321 infants failed in the hearing screening were tested under sleeping status, the ranges of response threshold distribution in ASSR of different frequencies were analyzed in each age group. ② The infants above 2 years old were also tested with VRA, and their response thresholds were compared between VRA and ASSR. ③ Evaluative standards: The response threshold was < 30 dB for normal hearing, 31-50 dB for mild hearing loss, 51-70 dB for moderate hearing loss, 71-90 dB for severe hearing loss, and > 91 dB for extremely severe hearing loss. MAIN OUTCOME MEASURES: ① ASSR results of the infants failed in the screening; ② Proportion of cases of each response threshold in each age group; ③ Comparison of ASSR response thresholds and VRA auditory thresholds in the infants of 2-3 years old. RESULTS: ①The response threshold was < 30 dB in 47.4% of the 321 infants failed in the initial hearing screening and secondary screening after 42 days. ② Severe to extremely severe hearing loss was detected in only 16 cases (8.3%) of the 193 infants of 0-6 months, in 9 cases (27.3%) of the 33 infants of 25-30 months, and 13 cases (39.4%) of the 33 infants of 31-36 months. Of the 193 infants of 0-6 months old who failed in the initial screening and the second screening after 42 days, the ASSR auditory threshold was < 30 dB in 97 cases (50.26%), 31-50 dB in 63 cases (32.6%), 51-70 dB in 17 cases (8.8%), 71-90 dB in 7 cases (3.6%), and > 91 dB in 9 cases (4.7%). ③ Among the 321 infants failed in the screening, the auditory threshold in the 6 age groups was < 30 dB in 47.4%, 31-50 dB in 27.1%, 51-70 dB in 8.4%, 71-90 dB in 6.2%, and > 91 dB in 10.9%. ④ The difference between ASSR response threshold and VRA auditory thresholds was 6-18 dB in the normal hearing group, mild and moderate hearing loss groups, and there was high correlation between them. The difference of ASSR and VRA thresholds was less than 5 dB between extremely severe and severe hearing loss groups, 5-13 dB between extremely severe and moderate-to-severe hearing loss groups (P < 0.05), and there was no significant differences between severe and moderate-to-severe hearing loss groups (P > 0.05). CONCLUSION: ① The hearing was normal in about half of the infants, although they failed in the primary screening and secondary screening. ② The proportion of the severity of hearing loss was increased along with aging. ③ Mild and moderate hearing losses are dominant in infants. ④ ASSR is reliable to evaluate the hearing of infants.
文摘This exploratory study examined the short-term reliability of cortical auditory evoked responses recorded from patients undergoing whole-head scalp elec-troencephalography (EEG) monitoring to assess their candidacy for surgical treatment of intractable focal seizures. Participants were 26 patients with either left-sided (N = 13) or right-sided focal epilepsy admitted to the hospital for continuous scalp EEG monitoring for possible epilepsy surgery planning. Cortical auditory evoked responses were recorded over multiple days from scalp EEG electrodes using tones presented binaurally in a passive oddball paradigm. Test-retest intervals were 1 - 6 days (mean 2 days). Test-retest reproducibility of the auditory N1 response was assessed by paired t-test (latency) and cross-correlation analysis (amplitude and latency). Within-patient comparisons of test-retest auditory N1 peak latencies revealed no significant differences. The cross-correlation coefficient indicated high test-retest reproducibility of the N1 waveform (rcc = 0.88). Seizure lateralization was not associated with asymmetries in N1 latencies or amplitudes. An N1 amplitude asymmetry (right > left) in patients with focal seizures originating from the left hemisphere was initially observed, but disappeared when patients with prior resections were excluded, suggesting that reduced left hemisphere tissue volume may account for the smaller N1 amplitudes. Test-retest reliability of cortical auditory evoked responses was unexpectedly high in patients with focal epilepsy regardless of seizure lateralization or localization. These findings challenge the view that neural responses are intrinsically unstable (unreliable) in patients with seizures.
文摘Spherical-symmetric steady-state response problem of piezoelectric spherical shell in the absence of body force and free charges is discussed. The steady-state response solutions of mechanical displacement, stresses, strains, potential and electric displacement were derived Sram constitutive relations, geometric and motion equations for the piezoelectric medium under external excitation (i.e. applied surface traction and potential) in spherical coordinate system. As an application of the? general solutions, the problem of an elastic spherical shell with piezoelectric actuator and sensor layers was solved. The results could provide good theoretical basis for the spherical-symmetric dynamic control problem of piezoelectric intelligent structure. Furthermore, the solutions can serve as reference for the research of general dynamic control problem.
文摘The auditory brainstern responses(ABR)and middle latency responses(MLR)were recorded in 24 normal mice with a 7S11A processor,and the normalparameters of ABR and MLR obtained.The results showed that the ABR of mice werecomposed of 6 waves,waves Ⅰ to Ⅵ.The mean threshold was 35.12±8.03 dB ,whichwas significantly different from the 22.63 dB of ABR found in guinea pigs.Thelatency of ABR waves Ⅰ to Ⅵizn the mice was found to be 1.30±8.03 ms ;2.02±0.24ms ;2.90±0.27 ms ;3.80±0.24 ms ;4.87±0.42 ms and 5.83±0.40 ms respectively.Nosex or strain differences were found.The MLR waveform of the mice were similar tothose of human and the latency was found to be P0 3.94±1.76 ms;P8.38±1.57ms;Na 14.98±2.54 ms;Pa 24.56±3.15 ms rcspectively.It is suggested that mice can beused for hearing research.Since the Na and Pa waves of MLR were unstable under anes-thesia,testing conditions for determining MLR in mice need further study.
基金supported by grants from the Science and Technology Innovation Nursery Foundation of PLA General Hospital(12KMM29)the military medical metrology research project(2012-JL1-028)+1 种基金Clinical Research Supporting Foundation of PLA General Hospital(2012FC-TSYS-3056)the Military Medical and Sanitation Research Project(11BJZ33)
文摘Objective To analyze the characteristics of auditory brainstem response (ABR) in presbycusis patients el-der than 90 years. Methods Fourteen presbycusis patients elder than 90 years (presbycusis group, 91.1.4 ± 1.3 years, 26 ears) and 9 normal-hearing young adults (control group, 22.7 ± 1.2 years, 18 ears) participated in the study. Alternative click-evoked ABRs were recorded in both groups. The peak latency (PL) of peak I,Ⅲ, and V, and the inter-peak latency (IPI) of I-Ⅲ,Ⅲ-V, and I-V were compared between groups. Results In elder presbycusis patients, the occurrence rate of peak I andⅢwere both 76.9%, and that of peak V was 84.6%. In presbycusis group, the peak latencies of I, Ⅲ, V were significantly longer than that of control group (P<0.001). There was no significant difference between groups in the IPI of peak I-IⅢ (P=0.298, peakⅢ-V (P=0.254) and peak I-V (P=0.364). Conclusions Auditory brainstem responses in presbycusis pa-tients elder than 90 years showed worse wave differentiation.
文摘Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate. Methods CM, CAP, DPOAE, and ABR were recorded as indicators of cochlear functions during whole cochlear perfusion. The morphology of the cochlea was studied via transmission electron microscopy. Results There were no significant changes in DPOAE amplitude before and after glutamate perfusion. CM I/O function remained nonlinear during perfusion. ABR latencies were delayed following glutamate perfusion. The average CAP threshold was elevated 35 dB SPL following glutamate perfusion.. The OHCs appeared normal, but the IHCs and afferent dendrites showed cytoplasmic blebs after glutamate perfusion. Conclusions While being a primary amino acid neurotransmitter at the synapses between hair cells and spiral ganglion neurons, excessive glutamate is neurotoxic and can destroy IHCs and spiral ganglion neurons. The technique used in this study can also be used to build an animal model of auditory neuropathy.
文摘This paper presents a closed-form algorithm for the steady-state response of elastic mecha-nisms. Based on an analytic expression of the initial conditions, the steady-state response can beobtained by just one cycle of integration, thus the algorithm is of high efficiency. The algorithm isthen verified by comparing the computational results with the previously published experimental re-sults.
基金supported by Natural Science Foundation of China[grant numbers 81760188]Scientific Research Fund of Guangxi Provincial Education Department [grant numbers 2017KY0103 (02601217023C)]
文摘To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews(30 ears) were stimulated with clicks and tone-pips at 11 different frequencies from 1 to 60 kHz. The ABR waves were recorded and analyzed. The ABR consisted of five to seven positive waves in the first 10 ms after a click stimulus, and the average hearing threshold of component III was 27.86 ± 3.78 dB SPL. Wave III was the largest and most clear. The ABR threshold was related to the tone-pip sitmulus by a "U" shaped curve. The sensitive frequency was approximately 8 kHz in tree shrews. The latencies systematically decreased with increasing stimulus frequencies. The ABR amplitudes of wave III increased as the sound pressure level increased. All of these results provide an empirical basis for future studies of hearing diseases in tree shrews.
基金supported by the National Natural Science Foundation of China(No.90820304,61105123,and 31100714)National Basic Research Program of China(No.2011CB933204)
文摘The auditory steady state response (ASSR) may reflect activity from different regions of the brain, depending on the modulation frequency used. In general, responses induced by low rates (_〈40 Hz) emanate mostly from central structures of the brain, and responses from high rates (〉80 Hz) emanate mostly from the peripheral auditory nerve or brainstem structures. Besides, it was reported that the gamma band ASSR (30-90 Hz) played an important role in working memory, speech understanding and recognition. This paper investigated the 40 Hz ASSR evoked by modulated speech and reversed speech. The speech was Chinese phrase voice, and the noise-like reversed speech was obtained by temporally reversing the speech. Both auditory stimuli were modulated with a frequency of 40 Hz. Ten healthy subjects and 5 patients with hallucination symptom participated in the experiment. Results showed re- duction in left auditory cortex response when healthy subjects listened to the reversed speech compared with the speech. In contrast, when the patients who experienced auditory hallucinations listened to the reversed speech, the auditory cortex of left hemispheric responded more actively. The ASSR results were consistent with the behavior results of patients. Therefore, the gamma band ASSR is expected to be helpful for rapid and objective diagnosis of hallucination in clinic.
文摘The auditory brainstem response (ABR) was measured for 90 cars of norml gui-nea pigs,from which the mean latency,amplitude and recognition of waves were obtain-ded.The waves were classified into six types,with wave Ⅲ as the main wave which ac-counted for 77.1% of all the waves.The frequency domain of each type was analysed bymeans of digital filtering and auto-regressive (AR)estimation.The main frequency com-position of ABR in the guinea pigs was restricted within 1600 Hz,in which there werethree peaks at AR spectrum,the mean value of the peaks being 107.33 Hz,566.67 Hzand 1076 Hz respectively.The AR spectrograms of all types waves were very similar toeach other.
基金a grant from theNational Natural Science Foundation of China (no:60578057).
文摘Objective To study local inflammatory response after implantation of hydroxyapatite synthetic ossicular prosthesis. Methods Hydroxyapatite granules were implanted in the bulla in 32 rats. Sham surgical procedures were performed in 10 rats as the control. Animals were sacrificed at 1 to 300 days after surgery. Bulla sections, stained with HE and Mallory’s azan, were examined for numbers and percentages of various inflammatory cell types. Results Slightly more inflammatory reaction was seen in animals with the implant than in the controls, mostly during the early stage following the implantation procedure. Few inflammatory cells were observed at later times. There were satisfactory fibrosis in both implanted and control ears. Conclusion The results indicate that hydroxyapatite synthetic prosthesis is a biocompatible implantation material in the middle ear. Nonetheless, the presence of inflammatory reaction immediately following implantation implies that control of infection is important in the early times after the implantation procedure.
文摘The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process employed in its study and the clinical experience required for its analysis. When analyzing the ABR, clinicians are often interested in the identification of ABR signal components referred to as Jewett waves. In particular, the detection and study of the time when these waves occur (i.e., the wave latency) is a practical tool for the diagnosis of disorders affecting the auditory system. In this context, the aim of this research is to compare ABR manual/visual analysis provided by different examiners. Methods: The ABR data were collected from 10 normal-hearing subjects (5 men and 5 women, from 20 to 52 years). A total of 160 data samples were analyzed and a pair- wise comparison between four distinct examiners was executed. We carried out a statistical study aiming to identify significant differences between assessments provided by the examiners. For this, we used Linear Regression in conjunction with Bootstrap, as a method for evaluating the relation between the responses given by the examiners. Results: The analysis suggests agreement among examiners however reveals differences between assessments of the variability of the waves. We quantified the magnitude of the obtained wave latency differences and 18% of the investigated waves presented substantial differences (large and moderate) and of these 3.79% were considered not acceptable for the clinical practice. Conclusions: Our results characterize the variability of the manual analysis of ABR data and the necessity of establishing unified standards and protocols for the analysis of these data. These results may also contribute to the validation and development of automatic systems that are employed in the early diagnosis of hearing loss.
文摘目的探讨多种听力学检测方法在听性脑干反应(ABR)最大输出未引出患儿的听力学诊断中的应用价值。方法回顾性分析69例(138耳)ABR最大强度未引出患儿的临床资料,年龄42天到5岁,平均1岁6个月,鼓室导抗图均为A型或正向单峰,声反射均未引出,影像学检查内耳无畸形。69例患儿均进行ABR、耳蜗微音电位(CM)、畸变产物耳声发射(DPOAE)和听性稳态反应(ASSR)测试。结果69例138耳中,8例16耳(11.59%)记录到CM,其中10耳(7.25%)记录到DPOAE,0.5、1、2、4 kHz ASSR反应阈值分别为83.2±13.1、82.9±13.0、75.3±12.4、63.1±9.1 dB nHL,结合其他检查结果诊断为听神经病。余61例(122耳)CM和DPOAE均未引出,0.5、1、2、4 kHz的ASSR引出率分别为82.3%、81.9%、76.9%、60.2%,其中20耳ASSR各频率均未引出,102耳至少一个频率引出,0.5、1、2、4 kHz ASSR反应阈分别为93.2±6.1、99.8±7.0、105.4±5.4、108.2±9.8 dB nHL,诊断为极重度感音神经性聋。结论对于ABR最大输出强度未引出的患儿,CM和/或DPOAE引出且ASSR各频率反应阈低于感音神经性聋患儿,有助于听神经病的诊断;CM和DPOAE均未引出有助于极重度感音神经性聋的诊断,ASSR测试有助于评估其残余听力。