• 제목/요약/키워드: Amplitude and Latency

검색결과 144건 처리시간 0.02초

Electrodermal Activity at Palms according to Pressure Stimuli applied to the Scapula

  • Kim, Jae-Hyung;Park, Gun-Cheol;Baik, Sung-Wan;Jeon, Gye-Rok
    • 한국멀티미디어학회논문지
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    • 제19권7호
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    • pp.1137-1145
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    • 2016
  • The system for measuring the electrodermal activity (EDA) signal occurring at the sweet glands in the human body was implemented in this study. The EDA measurement system (EDAMS) consisted of an algometer and the bio-potential measurement system (BPMS). Three experiments were performed using EDAMS. First, the linearity of the output voltage corresponding to the pressure being applied to an algometer was evaluated. The linearity of output voltage according to the pressure was 0.956. Second, the amplitude and the latency of the EDA signal at the left palm was obtained while applying the pressure stimuli to the left and right scapula. The latency of EDA signal was shorter whereas the amplitude of EDA signal was higher when the pressure applied was applied to the left scapula. Third, the amplitude and latency of the EDA was measured at left and right palm while increasing the pressure stimuli to the left scapula. The latency of EDA signal at left and right palm was decreased according to the intensity of pressure stimulus applied to the left scapula. However, the latency of the EDA signals did not show the linearity with respect to the pressure stimuli.

임상적으로 진단된 수근관증후군 환자에서 F파 분석 (F-Wave Analysis in Patients with Clinically Diagnosed Carpal Tunnel Syndrome)

  • 김성희;유봉구;김광수;유경무
    • Annals of Clinical Neurophysiology
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    • 제4권2호
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    • pp.108-113
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    • 2002
  • Background and Objective : Carpal tunnel syndrome (CTS) is the most common mononeuropathy encountered in clinical practice. No single procedure or group of procedures has demonstrated adequate sensitivity. F-wave study in CTS is very rarely reported. To determine the diagnostic usefulness of new parameters of F-wave and comparative study of F-wave parameters of median and ulnar nerves in patients with CTS. Methods : F-wave responses of median and ulnar nerves were analyzed from 27 patients with clinically diagnosed CTS and 22 age and gender-matched normal control. Conventional F-wave parameters were studied. Also, the usefulness of new parameters such as mean and maximal ulnar-median F-wave latency differences, ulnar-median F-wave persistence and chronodispersion differences, median/ulnar F-wave amplitude ratio, and F-wave conduction velocity (FCV) using mean and maximal latency were assessed. Results : Compared with controls, median F-wave minimal, maximal and mean latencies, mean F-wave amplitude/M-wave amplitude, minimal, mean and maximal ulnar-median F-wave latency differences, and FCVs using minimal, maximal and mean latency were significant (P<0.05~0.001). Median F-wave minimal, maximal and mean latencies, mean ulnar-median F-wave latency difference, and FCVs using minimal, maximal and mean latency showed high sensitivity and specificity. Mean ulnar-median F-wave latency difference and FCVs using maximal and mean latency were new parameters. Conclusion : New F-wave parameter including mean ulnar- median F-wave latency difference and FCVs using maximal and mean latency may be a useful to assess the CTS. Also, median F-wave minimal, maximal and mean latencies, and FCV using minimal latency may be included in routine diagnostic tests in CTS.

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Can Narrow Band Chirp Stimulus Shake the Throne of 500 Hz Tone Burst Stimulus for Cervical Vestibular Myogenic Potentials?

  • Ocal, F Ceyda Akin;Karacayli, Ceren;Coban, Volkan Kenan;Satar, Bulent
    • Journal of Audiology & Otology
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    • 제25권2호
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    • pp.98-103
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    • 2021
  • Background and Objectives: The aim of the study was to compare effects of tone-burst (TB) and narrow-band (NB) Claus Elberling (CE)-chirp stimuli on amplitude, latency and interaural asymmetry ratio (IAR) of cervical vestibular evoked myogenic potentials (cVEMP) in healthy individuals. Subjects and Methods: The study included 50 healthy volunteers. cVEMP procedure was carried out using 500 Hz TB and NB-CE-chirp stimulus (360-720 Hz, up-chirp) in random order. cVEMP were recorded at 100 dB nHL. For each ear and each stimulus, P1 latency, N1 latency and P1N1 amplitude were measured. IAR was also calculated. Results: Mean age was 26.66±9.48 years. cVEMP's in response to both TB and NB CE-chirp stimuli were obtained in all subjects. No statistically significant difference in P1 latency, N1 latency, and P1N1 amplitude was found between the right and left ears for both TB and NB CE-chirp stimuli (p>0.05). In both sides, P1 and N1 latencies were significantly shorter in NB CE-chirp stimulation compared to TB stimulation (p=0.000). In both sides, no statistically significant difference was found in P1N1 amplitude between two types of stimuli (p>0.05). Conclusions: The chirp stimulus produces robust but earlier cVEMP than TB does. This largest series study on NB chirp cVEMP shows that NB chirp is a good and new reliable alternative.

Can Narrow Band Chirp Stimulus Shake the Throne of 500 Hz Tone Burst Stimulus for Cervical Vestibular Myogenic Potentials?

  • Ocal, F Ceyda Akin;Karacayli, Ceren;Coban, Volkan Kenan;Satar, Bulent
    • 대한청각학회지
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    • 제25권2호
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    • pp.98-103
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    • 2021
  • Background and Objectives: The aim of the study was to compare effects of tone-burst (TB) and narrow-band (NB) Claus Elberling (CE)-chirp stimuli on amplitude, latency and interaural asymmetry ratio (IAR) of cervical vestibular evoked myogenic potentials (cVEMP) in healthy individuals. Subjects and Methods: The study included 50 healthy volunteers. cVEMP procedure was carried out using 500 Hz TB and NB-CE-chirp stimulus (360-720 Hz, up-chirp) in random order. cVEMP were recorded at 100 dB nHL. For each ear and each stimulus, P1 latency, N1 latency and P1N1 amplitude were measured. IAR was also calculated. Results: Mean age was 26.66±9.48 years. cVEMP's in response to both TB and NB CE-chirp stimuli were obtained in all subjects. No statistically significant difference in P1 latency, N1 latency, and P1N1 amplitude was found between the right and left ears for both TB and NB CE-chirp stimuli (p>0.05). In both sides, P1 and N1 latencies were significantly shorter in NB CE-chirp stimulation compared to TB stimulation (p=0.000). In both sides, no statistically significant difference was found in P1N1 amplitude between two types of stimuli (p>0.05). Conclusions: The chirp stimulus produces robust but earlier cVEMP than TB does. This largest series study on NB chirp cVEMP shows that NB chirp is a good and new reliable alternative.

The Latency of Distortion Product Otoacoustic Emissions in Ears with Hearing Impairment

  • Lee, Jung-Hak;Cho, Soo-Jin;Kim, Jin-Sook
    • 음성과학
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    • 제7권1호
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    • pp.77-87
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    • 2000
  • Distortion Product Otoacoustic Emissions (DPOAEs) can be measured in the external ear canal two fold: amplitude and latency, but most DPOAE studies deal with amplitude aspects. The purpose of this study was to investigate the latency of the 2f1-f2 DPOAEs in ears with hearing losses and to see if it could be a clinically useful method to distinguish normal from abnormal ears. For this purpose, DPOAE latency were measured as a function of frequency from 1 to 8 kHz in 30 ears with conductive and sensorineural hearing losses (SNHLs). DPOAEs were recorded with Otodynamic Analyzer ILO92. Results showed that the latency decreased as the frequency increased up to 8 kHz. The mean values of DPOAE latency for ears of SNHLs were shorter at all frequencies when they were compared to the mean values of normal ears. The latency in ears of conductive hearing losses was shorter than normal ears at the selective frequencies, as well. The results support the hypothesis that latency values are shorter in pathological ears.

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복합근육활동전위의 시작잠복기와 진폭에 대한 기준전극의 영향 (The Influence of the Reference Electrode on Compound Muscle Action Potential Onset Latency and Amplitude)

  • 이상무;손종희;최휘철
    • Annals of Clinical Neurophysiology
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    • 제12권1호
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    • pp.11-15
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    • 2010
  • Background: In belly-tendon (bipolar) montage, reference (R2) electrode placed on muscle's tendon has traditionally been considered to be electrically inactive. However, recent studies have revealed that R2 electrode is not simply referential, but actively contributes to compound muscle action potential (CMAP) waveform morphology. These findings suggest that CMAP onset latency and amplitude may also be influenced by the position of R2 electrode. This study was performed in order to evaluate the effect of R2 electrode position on CMAP onset latency and amplitude. Methods: We performed motor nerve conduction studies of median, ulnar, tibial and peroneal nerves on bilateral limbs of 20 normal subjects. We used traditional bipolar and monopolar montage and compared their CMAP onset latencies and amplitudes. In bipolar montage, recording (R1) electrode was placed on mid-belly of muscle with R2 electrode on the tendon of the muscle. In monopolar montage, R1 electrode was placed on the same site of bipolar montage, while R2 electrode was placed on the contralateral limb. Results: The mean CMAP onset latencies of median and peroneal nerves in bipolar montage were significantly different (p<0.05) with those in monopolar montage. And those of ulnar and tibial nerves were not significantly different (p>0.05). The mean CMAP amplitudes of all the tested nerves except ulnar nerve were significantly different (p<0.05). Conclusions: This study shows that change in R2 electrode position can affect the CMAP onset latency and amplitude, and these differences seem to be related to the generation of far field potential by CMAP.

Utilization of Averaging Process of Blink Reflex to Improve Diagnosis of Facial Nerve Palsy

  • Yoo, Jong-Kyun;Cho, Jeong-Hee;Kim, Dea-Sik
    • 대한의생명과학회지
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    • 제18권4호
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    • pp.391-398
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    • 2012
  • The conventional blink reflex has limited clinical application since it displays a wide range of change in the responses. Thus, we studied the blink reflex using the averaging process which is engaged in evoked potential studies in order to measure various responses such as latency, amplitude, and duration, which have been difficult to measure due to their wide ranges of changes. Among the Bell's palsy patient group, 13 patients who had the symptoms of incomplete palsy were examined to assess the results of the blink reflex through the averaging process. The subjects were 54 people in a normal group (108 eyes) and 18 patients (36 eyes) with Bell's palsy. For the study method, the conventional blink reflex and the blink reflex using the averaging process were measured for the people in the normal group, while in the Bell's palsy group, only the blink reflex using the averaging process was analyzed. In the case of the normal group, the blink reflex using the averaging process could measure all of the latency, amplitude, and duration. It was also observed that the latency, amplitude, and duration of R1, ipsilateral R2, and contralateral R2 significantly differed on the affected side of the Bell's palsy patients, compared to the unaffected side. The blink reflex using the averaging process should be more effective than the conventional method since the former can evaluate the latency, amplitude, and duration for Bell's palsy, while the latter can only assess latency.

정중운동신경과 척골운동신경의 전기생리학적 연구 (An Electrophysiologic Study on the Median Motor Nerve and Ulnar Motor Nerve)

  • 김종순;이현옥;안소윤;구봉오;남건우;김영직;김호봉;류재관;류재문
    • 대한정형도수물리치료학회지
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    • 제11권2호
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    • pp.62-70
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    • 2005
  • The determination of peripheral nerve conduction velocity is an important part to electrodiagnosis. Its value as neurophysiologic investigative procedure has been known for many years but normal value of median and ulnar motor nerve was poorly reported in Korea. To evaluate of median and ulnar motor nerve terminal latency, amplitude of CMAP(compound muscle action potential), conduction velocity and F-wave latency for obtain clinically useful reference value. 71 normal volunteers(age, 19-65 years; 142 hands) examined who has no history of peripheral neuropathy, diabetic mellitus, chronic renal failure, endocrine disorders, anti-cancer medicine, anti-tubercle medicine, alcoholism, trauma, radiculopathy. Nicolet Viking II was use for detected terminal latency, amplitude of CMAP, conduction velocity and F-wave latency of median and ulnar motor nerve. Data analysis was performed using SPSS. Descriptive analysis was used for obtain mean and standard deviation, independent t-test was used to compare between Rt and Lt side also compare between different in genders. The results are summarized as follows: 1. Median motor nerve terminal latency was right 3.00ms, left 2.99ms and there was no significantly differences between right and left side and genders. 2. Median motor nerve amplitude of CMAP was right 17.26mV, left 1750mV and there was no significantly differences between right and left side and genders. 3. Median motor nerve conduction velocity was right 57.89m/sec, left 58.03m/sec and there was no significantly differences between right and left side and genders. 4. Median motor nerve F-wave latency was right 25.74ms, left 25.59ms and there was significantly differences between genders. 5. Ulnar motor nerve terminal latency was right 2.38ms, left 2.45ms and there was significantly differences between right and left side. 6. Ulnar motor nerve amplitude of CMAP was right 15.99mV, left 16.02mV and there was no significantly differences between right and left side and genders. 7. Ulnar motor nerve conduction velocity was right 60.35m/sec, left 59.73m/sec and there was no significantly differences between right and left side and genders. 8. Ulnar motor nerve F-wave latency was right 25.53ms, left 25.57ms and there was significantly differences between genders.

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상지역동학 치료가 수근관 증후군 환자의 통증, 악력, 신경전도속도에 미치는 효과 (The Effects of Upper Limb Neuro Dynamic Treatment on the Pain, Grip Strength and Nerve Conduction Velocity of Patients with Carpal Tunnel Syndrome)

  • 유성훈;박성두;김태원;송현승;김진영
    • 대한정형도수물리치료학회지
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    • 제18권1호
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    • pp.49-56
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    • 2012
  • Background: When applying the upper limb neurodynamic treatment ULNT1 and upper limb neurodynamic treatment ULNT2, The object of this study evaluates the pain and grip strength, nerve conduction velocity and tries to present the treatment that is effective in the carpal tunnel syndrome through the comparison of effect between tests. Methods: The ULNT1 (n=10) and ULNT2 (n=10) was applied to the carpal tunnel syndrome in patient of 20 subject for 10 time 5 set during 4 weeks. Both groups received conventional physical therapy (hot pack with 30 minutes and ICT with 15 minutes and ultra sound with 15 minutes). Results: The ULNT1 showed the difference which the result of this study significantly in the median nerve motor latency, median nerve motor amplitude, median nerve sensory latency, median nerve sensory amplitude, grip strength and pain. ULNT2 showed the difference significantly in median nerve motor latency, median nerve motor amplitude, median nerve sensory latency, median nerve sensory amplitude and pain. Conclusions: If it implements by applying the traditional physiotherapy and ULNT1 and ULNT2 to the carpal tunnel syndrome subjects according to the subject state and function, the remedial value can be more enhanced.

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Electrodiagnostic study of Sympathetic Skin Response on Normal Korean Subjects

  • 김대식;우종균;김병원
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2009년도 추계학술발표논문집
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    • pp.501-504
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    • 2009
  • Sympathetic skin response (SSR) is defined as a minute change of skin potential after electrical stimulation. This test measures the change in voltage that originates from the surface of the skin and is attributed to sudomotor activity. The aim of this study was to define the criteria for validation of the responses. 40 normal subjects (20-73 years of age) with non-sympathetic dysfunction were tested and SSR was generated form all subjects. SSR latency was 1331.22${\pm}$177.51ms in the right palm, 1331.74${\pm}$156.42ms in the left palm, 1851.79${\pm}$220.99ms in the right sole, and 1874.10${\pm}$215.01ms in the left sole. And SSR amplitude was 595.83${\pm}$221.16${\mu}$V in the right palm, 605.33${\pm}$226.45${\mu}$V in the left palm, 291.76${\pm}$133.36${\mu}$V in the right sole, and 288.77${\pm}$129.70${\mu}$ V in the left sole. SSR latency and amplitude had no significantly difference between the right and the left side. SSR latency was consistently shorter (p<0.001) and SSR amplitude higher (p<0.001) in feet than in hands. SSR waveforms were P-type (32 subjects, 75%) and N-type (8 subjects, 25%), respectively. The SSR latency and amplitude in palms/soles were closely correlated with age (p<0.05) and height (p<0.05). The SSR test is one of methods assessing impairment of sympathetic fibers in peripheral neuropathy as well as a disorder of sympathetic system in other diseases and so our results from normal healthy subjects can be used as clinical criteria for SSR test.

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