Microvibration Research Articles

On the characterization and correlation of the rock failure-induced electromagnetic radiation and micro-vibration

A complete understanding of the rock fracture-induced electromagnetic radiation (EMR) mechanism and the coupling relationship between EMR and micro-vibration (MV) is highly challenging in rock engineering. For this purpose, a pioneer study is conducted that uses the synchronous monitoring experiments of EMR and MV during rock failure under uniaxial compression by the three-axis electromagnetic antenna and droplet-like MV acceleration sensors. The time-frequency evolution characteristics and correlation of EMR and MV during the failure process of rock under load were obtained, and the EMR-MV coupling effect was analyzed. The obtained results show dominant synchronicity of EMR and MV during the rock's failure process. It is inferred that both EMR and MV are generated with fracture (stress drop), and the signal intensity is proportional to the stress drop; the correlation coefficient between EMR and MV peak value is >0.85. During the rock's failure process, the peak vibration acceleration can reach 105 m/s2, and the attenuation speed of the MV signals was relatively faster than the EMR. However, the dominant frequencies of the two are both concentrated in the low-frequency band (< 30 kHz). The dominant frequency band of EMR is generally less than 20 kHz, while MV showed a slightly wider band, reaching 30 kHz. Besides, almost every fracture generated similar or the same main frequency (with a difference of 1–2 kHz) EMR and MV signals, indicating a noticeable correlation in the frequency domain. The analysis shows that the vibration during the rock's fracture can be regarded as small damping vibration to a certain extent, thus theoretically explaining its faster attenuation. The high time-frequency correlation between EMR and MV indicates that the EMR induced by rock fracture seems to be resulted by the vibrating charged crack clusters. In addition, the maximum EMR peak value mostly appears along the Z-axis of the EMR antenna, which further verifies the rationality of the above hypothesis. In brief, the charge accompanying rock fracture is the physical basis of EMR, and the vibration during the fracture process constitutes the power source of EMR. The research results further clarify the mechanism of EMR induced by rock fracture and lay a theoretical foundation for constructing the EMR location method for rock fracture sources.

Reinforcing the function of bone graft via the Ca-P ceramics dynamic behavior-enhanced osteogenic microenvironment for optimal bone regeneration and reconstruction

Bone tissue engineering is one of the most potential strategies in treating bone defect. However, implantation failure caused by the loss of biological activity has always been a difficulty in clinical transformation, resulting from the numerous cells death after implantation. Therefore, it is a burdensome challenge to design bone grafts with biological function adaptability. In this paper, we report a means to construct dynamically functional bone grafts (DFBGs) with Ca/P ceramics based on mechanical field drive-coupling and mechanobiology theory. In this study, the osteogenic microenvironment and cell functional activity are optimized by micro-vibration (MV) external field drive-coupled with biphasic calcium phosphate (BCP) ceramic, so that the DFBGs are endowed with optimal bone regeneration ability. The test results show that DFBGs have higher osteogenic differentiation ability and mechanical adaptability. The calcium release of BCP ceramics and the activation of calcium channels of cells are enhanced under MV field, thus the osteogenic potential of DFBGs is further up-regulated. The application results show that DFBGs system has excellent efficacy in guiding bone regeneration and the amount of new bone formation is about 35% higher than that of bone grafts (BGs) under static environment after implanted for 1 week, indicating expectable application prospect in treating bone defects.

Micro-vibrational erythrocyte sedimentation rate (ESR) for sensitive measurement of erythrocyte aggregation

The erythrocyte sedimentation rate (ESR) can act as a useful index of nonspecific disease activity in the diagnosis of inflammatory conditions. However, there are several drawbacks, including long time measurement. To promote ESR tendency, a micro-vibrational erythrocyte sedimentation rate (MV-ESR) was proposed. By controlling the profile of injecting flow rate into blood sample, air between the syringe pump and bottom of blood column was compressed and released. Micro-vibration (MV) is simple reciprocating flow including motion in both positive and negative directions in a line. It is determined as the edge of the interface between top of blood column and air is pinned under the pressure wave. From that, shear rate generated by determined MV is from 0 to 10–2 (s−1) in this study. Extremely low shear conditions may enhance the probability of erythrocyte aggregation formation. During measurement, a meniscus of separated plasma and sedimented erythrocytes was recorded using a camera. For validation of the proposed MV-ESR method, the effects of hematocrit as well as the frequency and amplitude of flow in the sedimentation tube were investigated. To quantify the enhancement of MV-ESR, the area of relative gradient (ARG) based on a relative gradient of 1 was used. When MV with a maximum flow rate of 1 mL/min and a period of 100 ms was produced until 15 min, MV-ESR exhibited the best performance. Then, the proposed technique was used to diagnose the ESR difference between a normal and periodontitis patient. The characteristic time (λESR), indicating the degree completion of the erythrocyte sedimentation, of the periodontitis patients was lower than that of the control. Based on the experimental demonstrations, λESR of the MV-ESR method has significant potential in the diagnosis of inflammatory conditions and prognosis of non-inflammatory conditions.

Sensing of Human Micro-vibration Transmitted Along Solid Using Pico-Tesla Magneto-impedance Sensor (pT-MI Sensor)

A new sensitive measurement method for the human micro-vibration (MV) is presented using a pico-Tesla resolution magneto-impedance sensor (pT-MI sensor). Various MV such as for the spinal-cord, the heart beat and following blood flow pulsation, and muscle tremors are stably detected by touching the skin position directly or indirectly via any solid transmission media to the sensor head which is dynamically rotated with more than 1.8 micro angular degree in the geomagnetic field. A blood flow promotion effect is detected using the MV sensing at the shoulder and the back of subjects after application of 6 Hz, 1μT pulse magnetic field in 10 min.

Characterisation of arm microvibration recorded on an accelerometer.

Microvibration (MV) of the freely hanging and firmly supported lower arm was studied (n = 8) using two accelerometers, one located over muscle tissue (brachioradialis muscle) and one over bony tissue (processus styloideus). Measurements were made in the completely relaxed arm (REST), during arterial occlusion (CUFF) and during mild handgrip (GRIP), first with the arm relaxed and hanging beside the chair and then repeated with the arm supported in a special rest. At REST. ballistocardiac forces were identified as the driving mechanism for the regular MV pattern, whereas actions of local pulse waves (CUFF) could be excluded. During GRIP irregular MV, related to the contraction process, became superimposed on both signals. The MV at REST was sensitive to arm position. In the freely hanging state, when the arm was family coupled to the trunk, ballistocardiac body motion was present over bony tissue, producing a low damped 7-13 Hz resonant response over muscle tissue. In the supported state, the arm became isolated from body motions. Nevertheless, ballistocardiac forces reached the arm, producing smaller oscillatory responses over bone and muscle tissue. Regionally produced MV (GRIP) was not sensitive to arm position, but the spectrum content in the 7-13 Hz region was very similar to REST. From these results it would appear, that a low damped 7-13 Hz resonance process exists in relaxed muscle tissue, which physiologically becomes stimulated by cardiac and muscle forces. From the close relationship of the simultaneous MV waveforms in the supported arm, evidence for mechanical coupling between bone and muscle tissue is given.

Effect of ceruletide on microvibration in schizophrenics

Ceruletide, a potent analogue of cholecystokinin, was administered by injection to eight schizophrenics treated with neuroleptics. We examined the dose–response effect on microvibration (MV) recorded from the chin of these patients. After 15 min of bed rest, MV was recorded for 5 min as a control recording. Subsequently, saline or ceruletide, at a dose of either 0.4 mg/kg or at 0.8 mg/kg, was injected according to a Latin square design with an interval of 4 weeks for washing out the drug effect and MV was recorded for 30 min. MV data obtained were subjected to the fast Fourier transform and an average power spectrum was computed. A three-way analysis of variance for these data was performed upon dose-effect, time-effect after treatment, and band-effect of the average power spectrum. The present results were similar to previous findings which had revealed effects of ceruletide on tardive dyskinesia symptoms, namely, the effects of ceruletide on MV were different according to the subjects (three cases: facilitation followed by inhibition, three cases: inhibition, two cases: no effects). The dose-response curve of ceruletide appears to be linear in some cases and an inverted U-shape in other cases. Present findings showed small doses of systemically administered ceruletide would modify muscle tonus of schizophrenics under chronic treatment of neuroleptics, and provided further reason for the therapeutic drug of tardive dyskinesia.

外傷性頸部症候群発症のメカニズムに関する電気生理学的考察

In order to elucidate the mechanism of the traumatic cervical syndrome, electrophysiological studies were conducted in rabbits. The greater occipital nerve (GON), cervical sympathetic trunk (SYMP) or both GON and SYMP (BOTH) was stimulated electrically with frequencies of the 3 Hz or 100 Hz. And diazepam (2-5 mg/kg) and pentazocine (3-6 mg/kg) were administered to observe the effect of these drugs on the cervical syndrome. The following was observed.1) The threshold of arousal reaction and the evoked muscular discharge due to stimulation of the brain stem reticular formation increased. The change with 100 Hz stimulation was more pronounced than with 3 Hz stimulation. The change in the arousal reaction was more pronounced than that of the evoked muscular discharge. The threshold changes were inhibited following administration of diazepam but not greatly inhibited by administration of pentazocine.2) The threshold of the evoked muscular discharge due to stimulation of t he cerebral cortex rose. The change was more prominent when BOTH was stimulated, and was inhibited following administration of diazepam.3) The threshold of the evoked muscular discharge due to stimulation of the hippocampus declined. The change with 3 Hz stimulation of SYMP was more marked than with 100 Hz stimulation of the SYMP, and was inhibited following administration of diazepam.4) The amplitude of the recruiting response due to stimulation of the VA with frequency of 8 Hz, increased markedly. This change disappeared following administration of diazepam, but was reversed following administration of pentazocine.5) The amplitude of the photo-evoked eyelid microvibration (MV) either increased or decreased. These changes were more prominent when SYMP was stimulated. In the cases of inhibition, the change due to GON stimulation alone was inhibited following administration of diazepam. In the cases of facilitation, diazepam had an effect on the change due to GON, SYMP or BOTH stimulation. Pentazocine had no effect in any of the cases.6) The amplitude of the sciatic evoked eyelid microvibration (SMV) increased. This change disappeared following administration of diazepam, and was inhibited following administration of pentazocine 6 mg/kg.7) The amplitu de of the nociceptive reflex decreased. The change due to GON or SYMP stimulation was inhibited following administration of diazepam, but pentazocine had no effect.8) The blood flow volume of the carotid and subclavicular arteries decreased with SYMP and BOTH stimulation, but that by GON stimulation remained almost unchanged. This change was inhibited following administration of diazepam, but was no affected by administration of pentazocine.9) Intestinal movement decreased by stimulation of these nerves. Diazepam inhibited this change markedly but pentazocine did not.10) In order to clarify the mechanis m of the above changes, VA and hippocampus were destroyed, and vagotomy was performed.The inhibition of, the arousal reaction and evoked muscular discharge due to stimulation of the brain stem reticular formation; evoked muscular discharge due to stimulation of the cerebral cortex; MV; and nociceptive reflex; all disappeared after VA destruction. The facilitation of, the evoked muscular discharge due to stimulation of the hippocampus; MV; and SMV; all disappeared after the widespread destruction of the hippocampus. The inhibition of intestinal movement did not disappear after vagotomy of both sides.

へん桃疾患における自律神経の関与に関する研究 自律神経機能検査による検討

To clarify the function of the autonomic nervous system in patients with various tonsillar diseases, the microvibration (MV) pattern and R-R interval of EGG were studied in these patients at rest and after tonsillectomy.R-R interval was below normal and MV frequency was abnormal in those with habitual tonsillitis or focal infection.After tonsillectomy, the R-R interval was significantly decreased in those with habitual tonsillitis or focal infection, compared with those with simple hypertrophic tonsil.The MV pattern showed a significant increase in the sympathetic nerve activity after tonsillectomy in those focal infection, compared with those with habitual tonsillitis or simple hypertrophic tonsil.

脳障害治療薬の効果検定に関する電気生理学的研究

The effect of destruction of the internal capusule, caudate, globus pallidus and putamen on threshold of the arousal reaction and evoked muscular discharge due to stimulation of cerebral cortex, photo-evoked eyelid microvibration (MV) and photopalpebral reflex (PPR) was investigated in the rabbit.The effect of administration of CDP-choline and TRH for 4 weeks was investigated using rabbits with experimentaly damaged internal capusule, and for the influence of stopping the administration of these drugs at the 2 weeks was also investigated.EEG activity following IC destruction was studied in rabbits by the topographic system.1) The threshold of the arousal reaction and evoked muscural discharge increased markedly following internal capusule destruction.2) The threshold increased slig htly following caudate, globus pallidus and putamen destruction, but did not show prominent changes in comparison with internal capusule des t r uction.3) The changes in amplitude of MV following internal capusule destruction was di vided into 2 groups, one in which the amplitude is decreased and the other in which the amplitu d e is increased.4) The amplitude of MV was increased after caudate and putamen destruction, and was decreased after globus pallidus destruction.5) The amplitude of the late comp onents (PPR5-PPR9) was depressed by internal capusule destruction, slightly intensified by caudate and putamen destruction, and slightly d e p ressed by globus pallidus destruction.6) The increase of thre shold in the arousal reaction and the evoked muscular discharge by internal capusule destruction was suppressed by administration of CDP-choline and TRH.7) TRH had a greater effect on the threshold of arousal reaction, while CDP-choline had a greater effect on the threshold of evoked muscular discharge.8) The suppressed amplitude of MV by internal capusu le destruction was restored and the increased amplitude of MV by internal capusule destruction was suppressed by admini s tration of CDP-choline.9) The suppressed amplitude of MV by internal capusule destruction was restored and the increased amplitude of MV by internal capusule destruction was more greatly increased b y administration of TRH.10) The suppressed ampulitude of the late components of PPR by internal capusule destruction was restored by the administration of CDP-choline.

Evaluation of muscular load of m. biceps brachii in isometric contraction with the use of microvibration.

The influence of load by maintaining isometric muscular contraction till exhaustion to microvibration (MV) on m. biceps brachii was studied with the use of MV sensor (MT-3T, acceleration type). The amplitude of MV was calculated with both band pass filter and integrator, while the frequency of MV was analyzed by Fourier transform and the power spectrum was obtained. It was found to be reasonable that the effective load to the muscle was evaluated not by the force but by the momentum which was the product of the force and endurance time till exhaustion.The momentum which corresponded to holding the force less than 25 %MVC (maximum voluntary contraction) till exhaustion increases the amplitude by about 40%, as compared with that at rest state. The augmentation of the momentum also increases the change of the peak frequency. The results indicated that MV as well as electromyogram could be applied to the evaluation of muscular fatigue in isometric contraction.

Microvibration-Related Responses to Optokinetic Stimulation

The body surface of all warm-blooded animals vibrates constantly. This phenomenon was termed microvibration (MV) by Rohracher. Since 1961 Kawata and students have been studying MV otolaryngologically and they detected slight changes with auditory and vestibular stimuli in the waves of MV. The authors observed changes in the MV responses in the upper extremities, in the presence of optokinetic stimulation. They found a close relationship between the direction of optokinetic stimulation and changes in the MV response. Therefore, these observations suggest that for MV recording, optic stimulation can be used to test the oculospinal reflex.

筋微小振動を指標としたそしゃく筋の機能特性把握 第１編 加速度センサを用いた測定方法の妥当性の検討

An attempt was made to apply microvibration (MV) on the skin surface of the skeletal muscle to investigate some functions of the masticatory muscle.The purpose of this study was to investigate the influences of the weight and the methods used for attaching the improved accelerometer on the acceleration output of the masseter muscle (Mm) and the anterior temporal muscle (Ta).For this purpose, the transmissibility on the skin surface of Mm and Ta of the vibration table driven by the regular continuous sinusoidal vibration was measured by sweeping the vibration frequency from 1 to 60Hz.Furthermore, the validity of this measurement system for MV with the improved accelerometer was checked by the other method using photoelectric principles without the sensing element making contact with the body.The results obtained were as follows:1) From investigations of the weight of the accelerometer (4, 8 and 12g), the accelerometer weighing 4g was considered appropriate.2) A comparison of three methods of attachment (surgical-tape, double-faced tape and adhesive) to Mm and Ta showed there was little difference between them.3) The transmissibility measured by the improved accelerometer corresponded to that measured by the photoelectric method.4) From the transmissibility for Mm and Ta, for a vertical directional vibration, the vibration behaviors of Ta showed a double resonance system and those of Mm showed a triple system, while for a horizontal directional vibration, those of Ta and Mm showed a single resonance system.

NLA変法(modified neuroleptanalgesia)の中枢作用機序に関する電気生理学的研究

An attempt was made to clarify the effects of the modified NLA on the central nervous system using Diazepam and Pentazocine. The unanesthetized rabbit was used as the experimental animal. The results obtained were as follows.1) Threshold of arousal reaction and evok ed muscular discharge rose more remarkably when Diazepam and Pentazocine were administered in the ratio of 1 to 3 than when either one of them was administered. This finding showed that the combination of the two agents had more inhibitory effect on consciousness and motor activity than either of them.2) Average threshold of arousal reaction in the hippocampus rose more rem arkably than in the cerebral cortex when the two agents were administered in the same way.3) Under the combination of the two agents, average threshold rose most remarkably in hind limbs, followed by fore limbs, the hippocampus and the cerebral cortex in this order.4) Under the combination of the two agents, threshold of evoked muscular d ischarge showed a marked elevation, about double the threshold of arousal reaction. This finding proved that the modified NLA had an inhibitory effect on the sensory nerve, and an even more powerful inhibitory effect on the motor nerve.5) Pentazocine showed as equally inhibitory effect as the combination of the two agents did on the early components of average evoked potential in the cerebral cortex. Consequently, it was clear that the effect on the afferent pathway was mostly attributed to Pentazocine.6) The late components (N4 and N5) of the average evoked potential in creased in the cerebral cortex under the combination of the two agents.7) The late components of the average evoked potential in the hippocampus were powerfully inhibited under the same condition. This finding made it clear that the combination of the two agents powerfully suppressed pain reaction.8) M and H waves showed no incre ase under the combination of the two agents, whereas they did with the administration of either one of them. This fact is advantageous to anesthetization in a surgical operation.9) The combina tion of the two agents showed powerful inhibition on the microvibration (MV).10) With regard to photopalpebral reflex (PPR), PPR6 showed an increase under the combination of the two agents.11) The rate of in crease of the threshold of arousal reaction and evoked muscular discharge diminished remarkably after the destruction of nucleus ventralis anterior (VA) under the combination of the two agents. This finding elucidated that the VA was concerned with the increase of the threshold of arousal reaction and evoked muscular discharge.12) The increase of N4, N5 and PPR6 under the combination of the two agents disappeared after the destruction of VA. It was therefore obvious that the increase of these responses was caused by excitement of the diffuse thalamocortical projection system.13) Recruiting response caused by excitement of the d iffuse thalamocortical projection system showed an increase under the combination of the two agents.14) The action potentials, VAN4 and VAN5, induced from the cerebral cortex by a 1Hz stimulation on the VA increased under the combination of the two agents. This finding led us to the conclusion that the increase in N4, N5 and PPR6 was a direct expression of the excitement of the diffuse thalamocortical projection system.

Influence of hyperbaric heliox environment at 31ATA on microvibration and electroencephalogram in four divers.

The simulated experiment of heliox dive to 31ATA in four subjects was periormed for one month including the pressure holding for one week. In order to study the influence of hyperbaric environment on physical condition and level of consciousness, microvibration (MV) on thenar and eyelid and electroencephalogram (EEG) on T4 and O2 were measured at various atmosphere conditions. The power spectrum of MV and EEG were calculated : The peak frequency of power spectrum and the magnitude of power spectrum at the peak frequency were evaluated. The amplitude of MV increased after compression as compared with the value at pre-compression i.e., 1ATA, and the tendency was emphasized on eyelid MV at post-compression i.e., 1ATA, whereas the peak frequency of MV did not change significantly throughout the experiment. A rerharkable hyperbaric effect was found in the evaluation of EEG peak frequency ; The lowering of the peak frequency was recognized during the process of compression, pressure holding, and decompression. As the high pressure nervous syndrome (HPNS), especially during compression, was not recognized here, MV was not used as a detector of omen of HPNS, but the hyperbaric effect on skeletal muscle was found in ballistocardiogram cornponent of MV due to the increase of the amplitude at post-compression. EEG denoted the lowering of level of consciousness during pressure holding, so that the result meant calling one's attention to the operation in hyperbaric environment of 31ATA.

生体の電気的諸現象に及ぼすキンドリング効果の影響(第1報)

An electrophysiological study was made with kindled rabbits (which were experimentaly produced in the amygdaloid nucleus, hippocampus, septal nucleus and cerebral cortex) on the electrical changes of photopalpebral reflex (PPR) and photo-evoked eyelid microvibration (MV).The results obtained were as follows.1) In control group, no rema r kable change was observed in the PPR and MV.2) In amygdaloid kindled-group, the period required for the completion of the kindling effect was 7 to 21 days (average,16 days). The afterdischarge was propagated to cerebral cortex and hippocampus on the first trial.3) In amygdaloid-kindled group, the afterdischarge threshold was from 0.7 upto 2.6mA (average,1.5mA). The duration time of afterdischarge extended from 2 to 13 sec. (average,6sec. ) on the first trial to 12 to 86 sec. (average,46.8 sec. ) on the last trial after the kindling effect was completed.4) In amygdaloid -kindled group, the amplitude of MV increased in the early stage, but stepped down later. The amplitude of PPR1_4,6,9 showed no marked change. The PPR7,8increased remarkably and the PPR5 slightly following the initiation of stmulation.5) In hippocampus-kindled group, the period required for the comp letion of the kindling effect was 19 to 190 days (average,72 days). The afterdischarge was propagated to the amygdaloid nucreus, but not to the cerebral cortex on the first triral.6) In hippocampus-kindled group, the afterdischarge threshold was from O.6 upto 1.4 mA (average,1. imA). The duration of the afterdischarge extended from 6.5 to 16 sec. (average,9.3 sec. ) on the first trial to 12 to 281 sec. (average,178 sec) on the last trial.7) In hippocampns-kindled group, the amplitude of MV increased remarkabl y following the initiation of stimulation. The amplitude of PPR 1-4 showed no marked change, while the PPR5-8 increased in amplitude. The PPR9 either increased or decreased by cases.8) In septal nudes-kindled group, the period required for the completion of the kindling effect was 17 to 38 days (average,26 days). The afterdischarge was propagated to the amygdaloid nucleus and hippocampus, but not to the cerebral cortex except one case on the first trial.9) In septal nucleus-kindled group, the afterdischarge threshold was from 1.8 upto 4.6mA (average,3.4mA). The duration of the afterdischarge extanded from 2 to 16 sec. (average,6.8 sec. ) on the first trial to 20 to 311 sec. (average,121 sec. ) on the last trial.10) In septal nucleus-kindled group, the amplitude of PPR1-4 showed no mark ed change, while the PPR5-9 incresed. The amplitude of MV increased in the early stage and later decreased gradually.11) In ce rebral cortex-kindled group, the period required for the completion of the kindling effect was 16 to 64 days (avetage,33 days). The afterdischarge was propagated to the amygdaloid nucleus and the hippocampus on the first trial.12) In cerebral cortex-kindled group, the afterdischar ge threshold was from 0 4 upto 3.8mA (average,1.4mA). The duration of the afterdischarge extended from 5 to 28sec. (average,13.6 sec. ) on the first trial to 14 to 206 sec. (average,67.6sec. ) on the last trial.13) In cerebral cortex-kindled group, the amplitude of MV increased. The amplitude of PPR1-4 showed no marked change, while the PPR5-9 increased.

聴覚誘発眼輪筋反射に関する電気生理学的研究第2編-中枢神経系の破壊および切断実験-

The pathway of the blink reflex elicited by auditory stimulation was investigated by means of destructions and transections in some parts of the central nervous system. The reflex was recorded as microvibrations of the eyelid (auditory-evoked eyelid microvibration, AMV).1) Bilateral electric lesions in the midbrain reticular formation resulted in a marked re duction or a disappearance of AMV.2) Lesions in the inferior colliculus reduced the amplitude of AMV, while lesions in the medial geniculate body had no effect.3) Temporal suppression of the cerebral cortex by KCI solution did not reduce the amplitude of AMV, but sometimes increased it. The same result was obtained after mechanical destruction including the hippocampus.4) The transecti ons of the brainstem at both the intercollicular and upper medullary level did not affect AMV. On the other hand, AMV disappeared after the transection at the postcollicular level.5) The se results suggest that the reflex pathway of AMV exists between lower midbrain and upper medulla, including the classical auditory pathway, peripheral to the inferior colliculus. AMV has a close relation to the function of the midbrain reticular formation, but does not have a direct relation to the cerebral cortex.6) AMV will be useful in evalua ting the function of the brainstem. Furthermore, MV (photo-evoked eyelid microvibration) is preferable to record in combination, to certify the localization of the lesion in the brainstem.

Photo-evoked eyelid microvibration (blink reflex elicited by flash stimuli) in newborns and children

The orbicularis oculi muscle contracts in response to photic stimulation. It was recorded as the microvibration of the eyelid contraction and it is called the photo-evoked eyelid microvibration (MV). MV was recorded using a special transducer on the central part of the upper eyelid from 167 subjects free of any neurological abnormalities. One G of the vibration was converted into 100 mV. The normal value was shown in newborns and children. The latency was 171.0 +/- 30.5 msec in newborns, 70.3 +/- 12.3 msec in 4 to 5 year-olds, 46.3 +/- 11.2 msec in 7 to 8 year-olds and 57.0 +/- 4.9 msec in adults. The latency of MV became shortened with growth. It is thought that the shortening of the latency during maturation is related to the myelination of the brainstem reticular formation and the maturation of the retina.

高浸透圧血症の中枢神経系に与える影響について(第4編)

The orbicularis oculi muscle contracts in response to photic stimulation as a reflexive action. It is called the photopalpebral reflex and is already present during the newborn period. In adults or animals, the photopalpebral reflex shows the function of the midbrain and cerebrum. It is known that hyperosmolality is a cause of intracranial hemorrhage and the dysfunction of the brain in newborns, but the functional damage is not yet clear. So the dysfunction of the brain induced by hyperosmolality can be examined and was in this study using the photopalpebral reflex, There are two ways of recording the palpebral reflex induced by photic stimulation one way utilizes the changes in the electrical potential between the upper eyelid and the ear, which is known as the photopalpebral reflex (PPR), and the other utilizes acceleration changes of eyelid microvibration, and is known as the photo-evoked eyelid microvibration (MV).The subjects were 9 newborns who had hyperosmolality 4 to 65 hours after birth,107newborns ranging in conceptional age from 25 to 45 weeks, and 5 children (4 to 9 years of age) free of any neurological abnormalities. In both methods, the electrode or pickup was applied to the central part of the upper eyelid with EEG paste and the average of 30 responses was calculated on a digital computer.The reproducibility of MV and PPR in the same individual was fairly good. PPR responses were observed in the following manner; the early component (PPR1,2,3 and PPR4) and the late component (PPRs and PPR5). The latency in the appearance of MV and PPR shortened with growth, but the amplitude of each reaction was not related to growth.In active sleep the latency of MV was prolonged and the amplitude was either markedly suppressed or completely lost. But in other sleep states the amplitude of MV was suppressed to about 30% of the responses in the awake state. While the amplitude of the late PPR component was also suppressed during sleep to about 30% of the amplitude in the awake state, the PPR never disappeared during active sleep. The latency of PPR1,2,3,4 and PPRs was not affected during sleep but the latency of PPR5 was affected. The latency of the late PPR component is the same as the latency of MV, so it is thought that these reactions have the same reaction pathway. And, because the amplitude of late PPR component and MV were suppressed during sleep, the reaction pathway might include the midbrain reticular formation.In the case of the early-infantile epileptic encephalopathy with suppression-burst, the late component of PPR and MV were completely lost, so it is suggested that the late PPR component and MV are related to the brainstem Because the early PPR com ponent alone disappeared upon the extraction of the right eye, it is believed that the early component is the ERG. As MV and the late PPR component were observed in the extracted side, the appearance of these reactions is related to the orbicularis oculi muscle and the movement of the eye scarcely affects these reactions.The latency of MV and PPR s were prolonged and the amplitude of MV and the late PPR component were suppressed with hyperosmolality. But the amplitude of the late PPR component was not directly proportional to the level of plasma osmolality. In newborns, it is believed that the dysfunction of the midbrain reticular formation caused by hyperosmolality can be studied by observing MV.

Potential changes and eyelid microvibration elicited by flash stimulation.

The photopalpebral reflex evoked in the upper eyelid of the rabbit by flash stimulation was studied in terms of potential change (PPR) and microvibration (MV) and the following conclusions drawn. (1) Of the PPR components, the early components from PPR1 to PPR4 are mainly ERG components, while PPR5 to PPR9 and MV are components appearing via the central nervous system. (2) Excitation of the brainstem reticular formation is involved in the appearance of the central PPR components and MV. Components PPR6 to PPR8 and MV originate in excitation of the same nervous tissue, but PPR9 occurs by excitation of different nervous tissue. (3) Contraction of the extraocular muscles, as well as the orbicularis oculi muscles, is involved in the appearance of MV. (4) Unit discharge takes place in the brainstem reticular formation coinciding with the occurrence of MV and an increase in discharge takes place later. The relation of the increase in this late discharge to PPR9 must be further investigated.

末しょう性顔面神経麻ひの臨床的研究 誘発（加算）筋電図検査，眼けん振動検査，眼けん微細振動測定による検討

A completely ideal and handy diagnostic test for facial paralysis has not yet been established. The effectiveness of the electrical test has been reported. It has, however, a few faults. For example, its reliability, the uneasiness patients feel and the actual impossibility of daily and continual testing. We, therefore, had to devise a surer electrical method as well as some supplemental methods for easier and handier diagnosis of facial paralysis.(I) The averaged potentials of the orbicularis oris muscle (ORm) and the orbicularis oculi muscle (OLm) was registered which were evoked by supramaximal electrical stimulation (from 8 to 32 times) by way of coaxial needle electrodes. Statistically, the latencies from 60 normal subjects were less dispersed (mean 3.2msec, standard deviation 0.45; ORm: mean 2.9msec, Standard deviation 0.42; OLm) than both their duration and amplitude. There were variously oifferent features in 120 patients. In patients with moderate denervation longer latency and reduced amplitude were found. In patients with advanced denervation, reduction of amplitude and intermittent lack of response in the graph were occasionally observed.(II) The lid vibration test (vibration divided into four stages from “0” to “3” according to its intensity) was performed on 60 patients. Some patients healed completely. The vibration stage of these patients went down at first but without getting to “0” (no vibration at all) it recovered speedily to “3” (normal condition). Other patients whose vibration stage once reached “0” had difficulty in recovery except for 18% of the people. This lid vibration stage has a correlation with the NMU-spike-discharge stage of OLm in the process of recovery.(III) Twenty-two subjects were examined quantatively with respect to microvibration (MV) on the lid surface with a crystal pick up and analyzed by a data analyzer. Ordinarily, voluntary contraction of OLm brought enlarged amplitudes compared with that when not contracted. But in the case of paralyzed patients, the contraction did not show such noticeable amplitudes. Therefore, the ratio of the mean MV amplitude when contracted to the mean when not contracted showed whether a patient was recovering favorably or not.(IV) The lid vibration test is a handy and both diagnostically and prognostically effective method which supplements the electrical test. Quantative measurement of MV on the lid surface is also an effective diagnostic method.