Ultrasound imaging of the serratus anterior muscle at rest and during contraction

The purpose of this study is to describe a clinically feasible method for measuring the thickness of the serratus anterior (SA) muscle using rehabilitative ultrasound imaging (RUSI) and to determine the reliability of repeated measures of that method. An exploratory clinical measurement study using a test–retest methodology was utilized to determine the reliability of the measurements in a sample of 20 healthy subjects. While sitting with the arm flexed 120°, the SA of each subject was imaged at rest, during an active hold and while holding a three pound weight. On Day 1, images were repeated three times for each condition by the same examiner. On Day 2, Examiner 1 and Examiner 2 repeated the scans. Images were examined offline by Examiner 1 with SA thickness measured superior to the most distal rib in the image. Reliability was evaluated using intraclass correlation coefficients (ICCs) and Bland–Altman plots. The intra‐examiner reliability (same day) during rest, active hold and active hold with resistance was ICC_3,3 = 0·892; ICC_3,3 = 0·951; and ICC_3,3 = 0·869–0·971, respectively. Intra‐examiner reliability between days ranged from ICC_3,2 = 0·613 at rest to ICC_3,2 = 0·736 during active hold with resistance. Interexaminer reliability was moderate during active hold (ICC_2,2 = 0·526) and active hold with resistance (ICC_2,2 = 0·535) and poor during rest (ICC_2,2 = 0·425). This study demonstrates that SA thickness can be measured reliably using RUSI by the same examiner and suggests that active movements may increase that reliability.     

Fiber-based polarization-sensitive OCT for birefringence imaging of the anterior eye segment

We demonstrate a prototype system of polarization-sensitive optical coherence tomography (PS-OCT) designed for clinical studies of the anterior eye segment imaging. The system can measure Jones matrices of the sample with depth-multiplexing of two orthogonal incident polarizations and polarization-sensitive detection. An optical clock is generated using a quadrature modulator and a logical circuit to double the clock frequency. Systematic artifacts in measured Jones matrices are theoretically analyzed and numerically compensated using signals at the surface of the sample. Local retardation images of filtering blebs after trabeculectomy show improved visualization of subconjunctival tissue, sclera, and scar tissue of the bleb wall in the anterior eye segment.OCIS codes: (110.4500) Optical coherence tomography, (170.4500) Optical coherence tomography, (170.4470) Ophthalmology, (120.2130) Ellipsometry and polarimetry     

Retinal, anterior segment and full eye imaging using ultrahigh speed swept source OCT with vertical-cavity surface emitting lasers

We demonstrate swept source OCT utilizing vertical-cavity surface emitting laser (VCSEL) technology for in vivo high speed retinal, anterior segment and full eye imaging. The MEMS tunable VCSEL enables long coherence length, adjustable spectral sweep range and adjustable high sweeping rate (50–580 kHz axial scan rate). These features enable integration of multiple ophthalmic applications into one instrument. The operating modes of the device include: ultrahigh speed, high resolution retinal imaging (up to 580 kHz); high speed, long depth range anterior segment imaging (100 kHz) and ultralong range full eye imaging (50 kHz). High speed imaging enables wide-field retinal scanning, while increased light penetration at 1060 nm enables visualization of choroidal vasculature. Comprehensive volumetric data sets of the anterior segment from the cornea to posterior crystalline lens surface are also shown. The adjustable VCSEL sweep range and rate make it possible to achieve an extremely long imaging depth range of ~50 mm, and to demonstrate the first in vivo 3D OCT imaging spanning the entire eye for non-contact measurement of intraocular distances including axial eye length. Swept source OCT with VCSEL technology may be attractive for next generation integrated ophthalmic OCT instruments.OCIS codes: (110.4500) Optical coherence tomography, (120.4640) Optical instruments, (140.3600) Lasers, tunable, (170.4460) Ophthalmic optics and devices, (170.4470) Ophthalmology     

The effects of shoulder joint abduction angles on the muscle activity of the serratus anterior muscle and the upper trapezius muscle while vibrations are applied

[Purpose] The purpose of this study was to examine the ratio between the upper trapezius and the serratus anterior muscles during diverse shoulder abduction exercises applied with vibrations in order to determine the appropriate exercise methods for recovery of scapular muscle balance. [Subjects and Methods] Twenty-four subjects voluntarily participated in this study. The subjects performed shoulder abduction at various shoulder joint abduction angles (90°, 120°, 150°, 180°) with oscillation movements. [Results] At 120°, all the subjects showed significant increases in the muscle activity of the serratus anterior muscle in comparison with the upper trapezius muscle. However, no significant difference was found at angles other than 120°. [Conclusion] To selectively strengthen the serratus anterior, applying vibration stimuli at the 120° shoulder abduction position is considered to be appropriate.Key words: Serratus anterior, Upper trapezius, Vibration     

20.0MHz超声对正常活体眼前节结构检测的初步研究

目的　探讨高频超声对眼前节结构的检测价值 ,为进一步研究眼前节组织疾病奠定基础。方法　用 2 0 .0MHz高频探头对 30例正常人眼的眼前节结构进行测量。结果　 2 0 .0MHz高频超声能清楚地观察角膜、虹膜、晶状体、睫状体、前房等结构。角膜呈一条弧形的高回声 ,中央厚度为 (0 .383±0 .0 31)mm ;前房为无回声 ,前房深度为 (2 .2 41± 0 .2 5 6 )mm ;虹膜呈短条状高回声 ,厚度为 (0 .419± 0 .0 44)mm ;晶状体前囊膜呈弧形高回声 ,晶状体内部为无回声 ,晶状体厚度为 (3 .5 33± 0 .185 )mm ;睫状体为类似三角形的中高回声 ,最厚处厚度为 (1.131± 0 .0 94)mm。结论　 2 0 .0MHz高频超声可无创性、清晰地观察正常眼的眼前节结构 ,对青光眼、角膜、巩膜、虹膜、晶状体、睫状体疾病的诊断有较大价值     

Reliability of ultrasound imaging of the transversus abdominis muscle in asymptomatic subjects

[Purpose] The purpose of this study was to assess intra-rater and inter-rater procedural reliability of ultrasound imaging measurements of transversus abdominis thickness. [Subjects] Thirty therapists who attended the B Hospital in Hwaseong participated in the study. [Methods] Two examiners assessed transverse abdominis thickness at rest and during contraction. Intra-class correlation coefficient with 95% confidence interval and, standard error of measurement were calculated. [Results] The intra-rater procedural reliability of ultrasound imaging measurements of transverse abdominis thickness, assessed using the intra-class correlation coefficient, was 0.65–0.86 (within-day, 0.65–0.86; between-day, 0.77–0.85). The inter-rater procedural reliability of ultrasound imaging measurements of transverse abdominis thickness, assessed using the intra-class correlation coefficient, was 0.72–0.86 (within-day, 0.72–0.86; between-day, 0.82–0.83). [Conclusion] Ultrasound imaging can be used as a reliable method for measurements of transverse abdominis thickness.Key words: Reliability, Transversus abdominis, Ultrasound imaging     

Transient absorption spectroscopy and imaging of redox in muscle mitochondria

Mitochondrial redox is an important indicator of cell metabolism and health, with implications in cancer, diabetes, aging, neurodegenerative diseases, and mitochondrial disease. The most common method to observe redox of individual cells and mitochondria is through fluorescence of NADH and FAD+, endogenous cofactors serve as electron transport inputs to the mitochondrial respiratory chain. Yet this leaves out redox within the respiratory chain itself. To a degree, the missing information can be filled in by exogenous fluorophores, but at the risk of disturbed mitochondrial permeability and respiration. Here we show that variations in respiratory chain redox can be detected up by visible-wavelength transient absorption microscopy (TAM). In TAM, the selection of pump and probe wavelengths can provide multiphoton imaging contrast between non-fluorescent molecules. Here, we applied TAM with a pump at 520nm and probe at 450nm, 490nm, and 620nm to elicit redox contrast from mitochondrial respiratory chain hemeproteins. Experiments were performed with reduced and oxidized preparations of isolated mitochondria and whole muscle fibers, using mitochondrial fuels (malate, pyruvate, and succinate) to set up physiologically relevant oxidation levels. TAM images of muscle fibers were analyzed with multivariate curve resolution (MCR), revealing that the response at 620nm probe provides the best redox contrast and the most consistent response between whole cells and isolated mitochondria.     

Combined indocyanine green and quantitative perfusion assessment with hyperspectral imaging during colorectal resections

Anastomotic insufficiencies still represent one of the most severe complications in colorectal surgery. Since tissue perfusion highly affects anastomotic healing, its objective assessment is an unmet clinical need. Indocyanine green-based fluorescence angiography (ICG-FA) and hyperspectral imaging (HSI) have received great interest in recent years but surgeons have to decide between both techniques. For the first time, two data processing pipelines capable of reconstructing an ICG-FA correlating signal from hyperspectral data were developed. Results were technically evaluated and compared to ground truth data obtained during colorectal resections. In 87% of 46 data sets, the reconstructed images resembled the ground truth data. The combined applicability of ICG-FA and HSI within one imaging system might provide supportive and complementary information about tissue vascularization, shorten surgery time, and reduce perioperative mortality.     

Comparison of the electromyographic activity of the tibialis anterior and gastrocnemius in stroke patients and healthy subjects during squat exercise

[Purpose] The purpose of this study was to compare the EMG activity of the tibialis anterior (TA) and gastrocnemius (GCM) during the downward, maintenance, and upward phases of the squat exercise and during passive ankle dorsiflexion range of motion between stroke patients and healthy subjects. [Subjects] Fifteen hemiplegic (8 males, 7 females) and 15 healthy subjects (4 males, 11 females) volunteered for this study. [Methods] All subjects performed a double-leg squat exercise with the knee joint flexed to 30°. Surface electromyography (EMG) signals were recorded from the TA and GCM on the paretic or nondominant side. Passive ankle dorsiflexion range of motion (DF PROM) was measured using a goniometer in the knee-extended prone position. [Results] In the downward and maintenance phases, TA activity was significantly higher in stroke patients compared with healthy subjects. In the upward phase, GCM activity was significantly lower in stroke patients compared with healthy subjects. Ankle DF PROM was significantly lower in stroke patients compared with healthy subjects. [Conclusion] The observed EMG patterns should be taken into consideration to inform and enhance therapy for stroke patients.Key words: EMG, Squat exercise, Stroke     

下壁导联ST段压低对前壁急性心肌梗死患者近期预后的影响

前壁急性心肌梗死时,心电图胸前导联抬高的同时可出现下壁导联ST段压低改变,这种改变的意义近年来常引起人们的重视。本文通过对36例前壁急性心肌梗死患者的心电图分析和临床观察,旨在探讨下壁导联ST段压低对前壁急性心肌梗死患者近期预后的影响。     

Gender differences in muscle blood volume reduction in the tibialis anterior muscle during passive plantarflexion

Physical flexibility, such as joint range of motion and muscle extension, may influence muscle blood volume. Women have been shown to have a greater degree of flexibility than men. We examined whether there is a gender difference in the relationship between fascicle length and muscle blood volume or oxygenation in untrained men and women. In 16 untrained men and thirteen untrained women, we measured the total‐[haemoglobin (Hb) + myoglobin (Mb)] (total‐[Hb + Mb]) and relative oxy‐[Hb + Mb] after calibrating baseline and arterial occlusion deoxygenation levels with near‐infrared spectroscopy. Also, fascicle length was measured with B‐mode ultrasonography at the tibialis anterior muscle during passive plantarflexion. Increases in fascicle length from baseline (ankle joint angle 120°, composed from the caput fibulae, the malleolus (pivot), and the distal epiphysis of the fifth metatarsal bone) were greater in women than in men during plantarflexion of 140° and 160° and the maximal angle without pain. However, the decreases in total‐[Hb + Mb] and relative oxy‐[Hb + Mb] from baseline were not different between women and men at any degree of plantarflexion. Moreover, fascicle length and total‐[Hb + Mb]/muscle thickness (men > women) showed a similar relationship, with muscle thickness increasing capillary compression. These findings indicate the possibility of a mechanical function underlying muscle blood volume during muscle stretching, which is greater in women than in men.     

Determination of the fascicle length of the gastrocnemius muscle during calf raise exercise using ultrasonography

[Purpose] The purpose of this study was to find a strength training protocol which maintains isometric contraction of the triceps surae during dorsal flexion of the ankle. [Subjects] The left feet of 22 young normal volunteers who did not have orthopedic injuries or lower limb pain participated in this study. [Methods] All subjects performed four sets of five repetitions of four sets calf-raise (CR) exercise at were (1) 60 bpm without a pedestal, (2) 60 bpm with a pedestal, (3) 90 bpm without a pedestal, and (4) 90 bpm with a pedestal. The fascicle length of the lateral head of the gastrocnemius and ankle angle were measured using ultrasonography and a video camera. The CR exercise was divided into two or three phases using the kinematics of the ankle. The average change in fascicle length over the five repetitions of each phase were compared. [Results] The change of the fascicle length during the hyper-dorsiflexion phase was significantly smaller than during the other two phases. [Conclusion] It is possible that eccentric CR exercises have progressed to motor learning of the isometric contraction during counter movement, and improved the release of elastic energy of the Achilles tendon during running, jumping, and other athletic activities.Key words: Gastrocnemius, Isometric contraction, Eccentric calf raise exercise     

Laser Doppler holography of the anterior segment for blood flow imaging,eye tracking,and transparency assessment

Laser Doppler holography (LDH) is a full-field blood flow imaging technique able to reveal human retinal and choroidal blood flow with high temporal resolution. We here report on using LDH in the anterior segment of the eye without making changes to the instrument. Blood flow in the bulbar conjunctiva and episclera as well as in corneal neovascularization can be effectively imaged. We additionally demonstrate simultaneous holographic imaging of the anterior and posterior segments by simply adapting the numerical propagation distance to the plane of interest. We used this feature to track the movements of the retina and pupil with high temporal resolution. Finally, we show that the light backscattered by the retina can be used for retro-illumination of the anterior segment. Hence digital holography can reveal opacities caused by absorption or diffusion in the cornea and eye lens.     

Chronaxie and accommodation index in the diagnosis of muscle denervation

OBJECTIVE: To determine the sensitivity of the combined measurement of chronaxie and the accommodation index in the qualitative diagnosis of muscle denervation with needle electromyography and to compare quantitative diagnoses. DESIGN: Ninety-three neurogenic muscles diagnosed by needle electromyography were consecutively included for measurement of chronaxie and the accommodation index in this prospective study. The sensitivity of qualitative diagnosis was assessed for all muscles, separately for the acute and subacute-chronic denervation phase and for the complete and partial denervation. RESULTS: The combined measurement of chronaxie and the accommodation index showed a 90% sensitivity to needle electromyography for qualitative diagnosis of muscle denervation for all muscles. A 100% sensitivity was found for the acute denervation phase and for complete denervation. The subacute-chronic denervation phase revealed a 86% sensitivity, and partial denervation had a 88% sensitivity. The kappa coefficients did not show satisfactory agreement in quantitative diagnosis, and Bowker's test revealed a statistically significant underestimation of muscle denervation for measurement of chronaxie. CONCLUSION: The combined measurement of chronaxie and the accommodation index can be recommended for the screening of neurogenic lesions in the acute denervation phase.     

Effects of shoe type on lower extremity muscle activity during treadmill walking

[Purpose] The purpose of this study was to analyze the effects of different shoe types on lower extremity muscle activity in healthy young women by using electromyography. [Subjects and Methods] Fifteen healthy young women in their 20s were included in this single-group repeated measures study. The subjects were divided into three groups: Converse sneakers, rain boots, and combat boots. The subjects walked on a treadmill at 4 km/h for 30 min, during which six muscles were examined using electromyography: the rectus femoris, vastus medialis, semimembranosus, tibialis anterior, peroneus longus, and medial head of the gastrocnemius. Between switching shoe types, a 24-h rest period was instated to prevent the fatigue effect from treadmill walking. [Results] One-way analysis of variance used to compare electromyography results among the three groups showed that the main effect of group differed significantly for the vastus medialis. Vastus medialis activity was higher in the rain boots group than the Converse sneakers group, and it was higher in the combat boots group than rain boots group. [Conclusion] Shoe type affects lower extremity muscle activity. Our findings may help individuals choose the ideal shoes for daily walking.Key words: Electromyography, Lower extremity, Shoe type     

Simultaneous real-time echocardiographic imaging of myocardial perfusion and regional function using color-encoded, contrast-enhanced power modulation

We hypothesized that color-encoded, contrast-enhanced, power modulation imaging could allow simultaneous quantification of myocardial perfusion and regional left ventricular function. We studied 12 anesthetized, closed-chest pigs at baseline, during acute ischemia, and during reperfusion, and 8 patients after acute myocardial infarction. Color kinesis was used to color encode endocardial motion during real-time contrast perfusion imaging with high-energy ultrasound pulses. Wall motion was assessed by calculating regional fractional area changes. Translation-free perfusion analysis was performed in automatically identified myocardial regions of interest. Steady-state intensity and postimpulse rate of contrast replenishment were calculated. In all animals, ischemia caused reversible changes in the images and the perfusion- and function-calculated indices. A significant decrease in pixel intensity (14%) and contrast replenishment rate (66%) in left anterior descending coronary artery segments, in agreement with fluorescent microspheres measurements, coincided with a decrease in fractional area change (34%). For patients, respective perfusion and function indices were 61%, 51%, and 58% lower in segments where perfusion defects, regional wall-motion abnormalities, or both were noted in gray scale images. Color-encoded, contrast-enhanced power modulation allows simultaneous real-time imaging and quantitative analysis of myocardial perfusion and regional left ventricular function.     

Functional coupling between anterior prefrontal cortex (BA10) and hand muscle contraction during intentional and imitative motor acts

The present study tested the hypothesis that functional cortico-muscular coupling is a putative physiological mechanism by which Brodmann area 10 (BA10) of anterior prefrontal cortex controls subjects' behavior. Intracerebral stereo electroencephalographic (SEEG) data were recorded from BA10 of epilepsy subjects in the course of pre-surgical monitoring. During the SEEG recordings, these subjects were engaged in three conditions: the execution of intentional hand muscle contractions as triggered by auditory stimuli ("EXE"); the execution of the same muscle contractions as an imitation of a person seated in front of the subject ("IMI"); and the mere observation of the hand muscle contractions performed by that person ("OBS"). SEEG frequency bands of interest were theta (4-7 Hz), alpha (8-12 Hz), beta 1 (13-21 Hz), beta 2 (22-30 Hz), and gamma (31-45 Hz). Results showed that functional cortico-muscular coupling at gamma band was higher in amplitude during the intentional muscle contraction ("EXE") than the other conditions ("IMI" and "OBS"). Instead, cortico-muscular coupling at theta band was higher in amplitude during the imitative muscle contraction ("IMI") than the other conditions ("EXE" and "OBS"). In parallel, there was an increase of SEEG gamma band power during the intentional muscle contraction and an increase of SEEG theta band power during its imitation. The present results suggest that anterior prefrontal cortex (BA10) might control subjects' behavior by means of functional cortico-muscular coupling at selective frequency bands (theta and wide gamma rhythms).     

Comparisons of shoulder stabilization muscle activities according to postural changes during flexi-bar exercise

[Purpose] The purpose of this study was to compare shoulder stabilization muscle activities according to postural changes during flexi-bar exercise. [Subjects] The subjects included 18 students (10 males, 8 females) at B University. [Methods] The subjects performed the following flexi-bar exercises: 1) medio-lateral oscillation with the 90° shoulder abduction, with the hand in the neutral position; 2) dorso-ventral oscillation with 90° shoulder flexion, with the hand in the neutral position; 3) superior-inferior oscillation with 90° shoulder flexion, with the 80° hand pronation. [Results] The activity of the serratus anterior showed significant differences between each position; however, activities of the upper trapezius and middle trapezius were not significantly different. [Conclusion] The results of this study indicate that posture control is important for selective strengthening of the serratus anterior muscle during flexi-bar exercises.Key words: Flexi-bar exercise, Shoulder stabilization, Muscle activity     

Retinal oxygen kinetics imaging and analysis (ROKIA) based on the integration and fusion of structural-functional imaging

The retina is one of the most metabolically active tissues in the body. The dysfunction of oxygen kinetics in the retina is closely related to the disease and has important clinical value. Dynamic imaging and comprehensive analyses of oxygen kinetics in the retina depend on the fusion of structural and functional imaging and high spatiotemporal resolution. But it’s currently not clinically available, particularly via a single imaging device. Therefore, this work aims to develop a retinal oxygen kinetics imaging and analysis (ROKIA) technology by integrating dual-wavelength imaging with laser speckle contrast imaging modalities, which achieves structural and functional analysis with high spatial resolution and dynamic measurement, taking both external and lumen vessel diameters into account. The ROKIA systematically evaluated eight vascular metrics, four blood flow metrics, and fifteen oxygenation metrics. The single device scheme overcomes the incompatibility of optical design, harmonizes the field of view and resolution of different modalities, and reduces the difficulty of registration and image processing algorithms. More importantly, many of the metrics (such as oxygen delivery, oxygen metabolism, vessel wall thickness, etc.) derived from the fusion of structural and functional information, are unique to ROKIA. The oxygen kinetic analysis technology proposed in this paper, to our knowledge, is the first demonstration of the vascular metrics, blood flow metrics, and oxygenation metrics via a single system, which will potentially become a powerful tool for disease diagnosis and clinical research.