Quantification of caffeine in coffee cans using electrochemical measurements, machine learning, and boron-doped diamond electrodes.

Electrochemical measurements, which exhibit high accuracy and sensitivity under low contamination, controlled electrolyte concentration, and pH conditions, have been used in determining various compounds. The electrochemical quantification capability decreases with an increase in the complexity of the measurement object. Therefore, solvent pretreatment and electrolyte addition are crucial in performing electrochemical measurements of specific compounds directly from beverages owing to the poor measurement quality caused by unspecified noise signals from foreign substances and unstable electrolyte concentrations. To prevent such signal disturbances from affecting quantitative analysis, spectral data of voltage-current values from electrochemical measurements must be used for principal component analysis (PCA). Moreover, this method enables highly accurate quantification even though numerical data alone are challenging to analyze. This study utilized boron-doped diamond (BDD) single-chip electrochemical detection to quantify caffeine content in commercial beverages without dilution. By applying PCA, we integrated electrochemical signals with known caffeine contents and subsequently utilized principal component regression to predict the caffeine content in unknown beverages. Consequently, we addressed existing research problems, such as the high quantification cost and the long measurement time required to obtain results after quantification. The average prediction accuracy was 93.8% compared to the actual content values. Electrochemical measurements are helpful in medical care and indirectly support our lives.

Surface EMG Pattern Recognition Using Long Short-Term Memory Combined with Multilayer Perceptron.

Motion classification based on pattern recognition of surface EMG (sEMG) signals is a promising approach for prosthetic control. We present a pattern recognition model that combines long short-term memory (LSTM) network with multiplayer perceptron (MLP) for sEMG signals feature learning and classification. The LSTM network captures temporal dependencies of the sEMG signals while the MLP has no inherent temporal dynamics but focuses on the static characteristics. The combination of the two networks would learn a feature space that contains both the dynamic and static information of the sEMG signals, which helps to improve the motion classification accuracy. The architecture of the proposed network was optimized by investigating the appropriate width and depth of the neural network as well as the dropout to achieve the best classification results. The performance of the proposed pattern recognition model was evaluated using Ninapro database. The results show that the proposed model can produce better classification accuracy than most of the well-known recognition techniques.

[A Case of Juvenile Cerebral Infarction due to Reversible Cerebral Vasoconstriction Syndrome].

A 19-year-old woman had a thunderclap headache, followed by left hemiparesis and left homonymous hemianopsia. Laboratory tests showed no signs of infection and immunological test results were unremarkable. MRI revealed a cerebral infarction in the right posterior cerebral artery territory, and digital subtraction angiography(DSA)showed right posterior cerebral artery stenosis on day 2. The first follow-up DSA demonstrated an irregular, bead-like appearance on day 9, but the stenotic lesion returned to normal on day 21. Reversible cerebral vasoconstriction syndrome should be suspected in cases of rapid resolution of symptoms.

Imbalance in multiple sclerosis and neuromyelitis optica: association with deep sensation disturbance.

Abnormality in balance is one of the most important causes of gait disturbance which has a direct impact to disability and medical cost in multiple sclerosis (MS) and neuromyelitis optica (NMO). However, characteristics of imbalance in these two diseases have not been fully elucidated. The aim of this study was to evaluate the degree and features of imbalance using stabilography, the degree of deep sensation disturbance using tibial nerve somatosensory evoked potentials (SEP), and their association with clinical impairment, in patients with MS and NMO. Seven NMO patients and seven MS patients with balance disturbance were examined. The relationship among stabilography measurements representing the degree and features of imbalance, height-adjusted P38 peak latency of SEP, and neurological functional disability, were analyzed. Stabilography evaluation showed a significantly severer degree of imbalance in NMO than in MS. Romberg quotient of the patients with brainstem lesions was significantly larger than those without them. In all patients, length of excursion per second significantly correlated positively with anterio-posterior-axis power spectra at intermediate frequency band. In all patients and in NMO, P38 peak latency adjusted by height significantly correlated positively with anterio-posterior-axis power spectra at intermediate frequency band. These findings suggest that the degree of imbalance of MS and NMO possibly correlate with deep sensation disturbance, which could be evaluated by anterio-posterior-axis power spectra at intermediate frequency band by stabilography. Severer imbalance in NMO than MS may be associated with the severe longitudinally extensive spinal cord lesions.

[Acute Subdural Hematoma in Snowboarders:A Multivariate Analysis of 79 Cases].

Snowboarding-related head injuries have become less common as the number of snowboarders has decreased;however, severe head injuries, such as acute subdural hematomas, occur every snowboarding season. We investigated the characteristics of cases of snowboarding-related acute subdural hematoma treated at our hospital. A total of 3,632 patients with snowboarding-related head injuries seen at our hospital between the 1995/96 and 2012/13 snowboarding seasons were enrolled in this study. Seventy-nine(2.2%)patients were diagnosed with acute subdural hematomas using computed tomography. We statistically analyzed the patient questionnaire responses, clinical records, and radiological findings. We compared the findings of the acute subdural hematoma(ASDH)group with those of the non-ASDH group. Among beginners, falling on a slope, incidents involving gentle slopes, and injuries of unknown origin were significantly more common in the ASDH group. On the other hand, among the intermediate snowboarders, incidents involving jumps, jump failure, and collisions with other snowboarders were more common in the non-ASDH group. Secondly, in an analysis involving subjects who had an ASDH, we compared the beginner group with the intermediate/advanced group. Falling on a slope, incidents involving gentle slopes, pure ASDH, diffuse brain swelling, and death were more common in the beginner group, and ASDH combined with contusions or subarachnoid hemorrhaging and incidents involving a jump were more common in the intermediate/advanced group. Finally, we summarized the cases of 10 subjects with an ASDH as well as diffuse brain swelling. Nine of the 10 patients died, 8 were first-timers or beginners, 6 had incidents involving flat or gentle slopes, and 5 had fallen on a slope. Snowboarding is a recreational sport;therefore, snowboarders must take responsibility for their actions. However, snowboarders, especially beginners, could decrease their risk of ASDH if they are informed about ASDH and take precautions to reduce their risk of falling on gentle slopes. Educational activities related to this topic should continue.

[Multiple and simultaneous intracranical hemorrhages with homocysteinemia].

A decreased intake of brightly colored vegetables results in increased levels of serum homocysteine, and homocysteinemia is associated with the progression of arteriosclerosis. Moreover, homocysteinemia is a known risk factor for cerebral infarction. Here, we report three cases wherein multiple simultaneous intracranial hemorrhages developed in the presence of homocysteinemia. The dietary habits of the patients involved indicated that decreased intake of brightly colored vegetables and the consequent progression of arteriosclerosis caused intracranial hemorrhage. Thus, in daily medical care, the measurement of serum homocysteine levels is useful for managing dietary habits and progression of arteriosclerosis.

Prediction of the muscle strength by the muscle thickness and hardness using ultrasound muscle hardness meter.

PURPOSES: The present study investigated whether a combination of the thickness and hardness of muscles without muscle tension can be used to estimate muscle strength during knee extension in adult males and females. METHODS: Seventy-two males and thirty-three females, whose ages ranged from 18 to 35 years, participated in this study. We measured muscle thickness and hardness in the right anterior region of the thigh (rectus femoris muscle and vastus intermedius muscle) without muscle tension using an ultrasound muscle hardness meter, and the maximal voluntary isometric contraction of right knee extension (MVIC). The changing ratios (%) of the tissue thickness before compression to those during compression (compression ratio) are calculated as an index of the hardness. Higher ratio indicates a harder muscle compared with that of other individuals showing the same muscle thickness. RESULTS: In male group, although the MVIC had significantly positive correlation to both muscle thickness (r=0.412, p<0.01) and compression ratio (r=0.233, p<0.05), their variables also had correlation mutually. In the female group, the MVIC has significantly positive correlation to only compression ratio (r=0.499, p<0.01), not muscle thickness (r=0.225, n.s.). On multiple linear regression analysis, the combination of two parameters (muscle thickness and compression ratio) allowed more accurate estimation of MVIC (r=0.573, p<0.01) in the female group. CONCLUSION: These findings suggested that the combination of muscle thickness and hardness is capable of effectively estimating muscle strength especially in females.

Differences in clinical characteristics of head injuries to snowboarders by skill level.

BACKGROUND: Many reports have compared head injuries between snowboarding and skiing. However, detailed studies comparing snowboarding head injuries between beginners and intermediates/experts have been lacking. PURPOSE: The authors investigated differences in clinical characteristics of head injuries to snowboarders between beginners (group B) and intermediates/experts (group IE). STUDY DESIGN: Descriptive epidemiology study. METHODS: The study population included 2367 patients treated at Saito Memorial Hospital and Yuzawa Community Health Medical Center, Niigata Prefecture, Japan, during 9 seasons from 1999-2000 to 2007-2008. RESULTS: Group B comprised 959 patients (mean age, 23.0 years; 52% males). Group IE comprised 1408 patients (mean age, 24.8 years; 72% males). Accidents in group B predominantly occurred as falls on gentle slopes (37%) and intermediate slopes (33%), whereas accidents in group IE occurred mostly during jumping (48%). The impact point on the head was predominantly occipital in both groups, but group IE showed a significantly higher frequency of trauma to the frontal region. The ratio of neurologic abnormalities was significantly higher in group IE. However, the ratio of surgical cases was significantly higher in group B (n = 10, 1.04%) than in group IE (n = 5, 0.36%). More acute subdural hematomas were seen in group B, but more fractures, contusions, and acute epidural hematomas were seen in group IE. Four moderate disabilities, 2 comatose patients, and 2 deaths were seen in group B, and 1 moderate disability, 2 severe disabilities, and 1 death were seen in group IE during this study. CONCLUSION: The data suggest significant differences in clinical states between beginners and intermediates/experts. Preventive methods for severe head injuries among snowboarders need to be devised based on differences in skill levels.

Direct visualization of ultrasonic power distribution using mechanoluminescent film.

In this research, a technique for measuring ultrasonic power with a mechanoluminescent (ML) sensing film was developed. A linear relationship was observed between the ultrasonic power and the ML intensity induced by ultrasonic vibration, indicating that ultrasonic power can be evaluated by measuring ML intensity. In addition, the ultrasonic power distribution on the surface of a transducer was visualized by recording ML images with a charge-coupled device camera.

A simple and useful coma scale for patients with neurologic emergencies: the Emergency Coma Scale.

OBJECTIVES: The Emergency Coma Scale (ECS) was developed in Japan in 2003. We planned a multicenter study to evaluate the utility of the ECS by comparison of the ECS and the Glasgow Coma Scale (GCS). METHODS: Ten medical facilities, including 4 university hospitals in Japan, participated in this study. We evaluated and recorded the level of consciousness, using the ECS and GCS, of all patients transported to these medical facilities by ambulance. We then performed a statistical analysis of the level of rater agreement of each scale using the average weighted κ coefficient according to the types of diagnosis at time of discharge and the occupations of the raters. We then evaluated the relationship between outcome of patients and their scores on the ECS and GCS by logistic regression analysis. RESULTS: The ECS showed the greater agreement among raters in patient scoring (0.802). In patients with traumatic brain injury and cerebrovascular disease, the ECS also yielded the higher agreement (0.846 and 0.779, respectively). The ECS score appears to be more strongly related than the GCS to patient outcome as measured by the Glasgow Outcome Scale (GOS). CONCLUSIONS: Our results showed that the ECS is a simple and readily understandable coma scale for a wide range of professionals in the field of neurologic emergencies. Furthermore, ECS appears to be suitable for evaluating patients in neurologic emergency settings.

Development of a flexible system for measuring muscle area using ultrasonography.

Muscular strength can be estimated by quantification of muscle area. For this purpose, we developed a flexible measuring system for muscle area using ultrasonography. This method is completely safe and is particularly suitable for elderly people because the subjects are not required to perform any muscular contraction during measurement. The ultrasound probe is installed on a mechanical arm, and continuously scans fragmental images along the body surface. A wide-area cross-sectional image is then constructed using the measured images. The link mechanism is very flexible, enabling the operator to measure images for any body posture and body site. Use of the spatial compounding method reduces speckle and artifact noise in the resultant cross-sectional images. The operator can observe individual muscles (extensor, flexor muscle, etc.) in detail. We conducted experiments to evaluate the performance of the system. In the experiments, the position of the ultrasound probe was calculated with high accuracy according to the link posture. In addition, a high degree of correlation was verified between MR images and those of the developed system. We observed a reduction in noise due to use of the spatial compounding method, and propose a new calibration method for correcting the measured muscle area, which were slightly deformed by the contact pressure of the ultrasound probe. Finally, we examined the relation between muscular area and muscular strength in young and middle-aged subjects. The results of these experiments confirm that the developed system can estimate muscular strength based on muscular area.

[Cerebral infarction suspected due to dissection of intracranial carotid artery in 2 children].

Intracranial cerebral artery dissection in children is very rare. We report 2 children who were diagnosed as having cerebral infarction which was suspected to be due to dissection of intracranial cerebral artery. Case 1: An 11-year-old girl presented with conscious disturbance and hemiparesis after seizure. Computed tomography (CT) showed cerebral infarction in the right frontal lobe. Her symptoms did not change, but angiography demonstrated reversible change. She received conservative therapy. Case 2: A 10-year-old boy complained of headache, and presented nausea and monoparesis of the left upper extremity. CT showed cerebral infarction in the right frontal lobe. He received superficial temporal artery-middle cerebral artery anastomosis because his symptoms fluctuated. In both cases, cerebral angiography showed string sign from the supraclinoid portion of the internal carotid artery to the middle and the anterior cerebral artery. Follow-up angiography showed improvement of stenosis. In pediatric cases of cerebral artery dissection, improvement with conservative therapy is frequently reported. It is necessary to follow-up such patients closely using magnetic resonance angiography or conventional angiography to determine whether or not surgery is indicated.

Calibration of cross-sectional images measured by an ultrasound-based muscle evaluation system.

The quantification of muscle volume can be used to estimate muscular strength. Therefore, we developed a flexible measuring system for muscle volume using ultrasonog-raphy. In the measuring process, subjects are not required to perform any muscular contraction, so it is completely safe and particularly suitable for elderly people. The ultrasound probe is installed on a mechanical arm, and continuously scans fragmental images along the body surface. The measured images are then composed into a wide area cross-sectional image. However, the muscle area measured by our system was slightly smaller than that measured by MRI. because the ultrasound probe contacted the body surface with a little pressure during the measurement. The strain then decreases the total image size and its circumference. This paper introduces our developed system and proposes a new calibration method for the muscle area in the thigh based on its circumference.

Automated discrimination method for measuring the thickness of muscular and subcutaneous fat layers based on tissue elasticity.

The balance between human body composition, e.g. bones, muscles, and fat, is a major and basic indicator of personal health. This paper proposes a new discrimination method for measuring the thickness of subcutaneous fat and muscular layers based on tissue elasticity. The validity of the proposed method was evaluated in twenty-one subjects (twelve women, ten men; aged 20-70 yr) at three anatomical sites. Experimental results show that the proposed method can achieve considerably high discrimination performance.

Giant plexiform neurofibroma and suboccipital meningocele manifesting as segmental neurofibromatosis.

A 34-year-old woman presented with segmental neurofibromatosis manifesting as a soft lump with a large café-au-lait macule on her occipital region and neck. Magnetic resonance imaging showed a thick skin tumor in the occipital region and posterior neck, and a suboccipital meningocele which seemed to have no association with her symptoms. Biopsy lead to a histological diagnosis of giant plexiform neurofibroma. During biopsy, massive local bleeding occurred and hemostasis was achieved by electrocautery and meticulous suture ligation. The postoperative course was uneventful and observation was continued for both the giant plexiform neurofibroma and the meningocele.

[Bickerstaff's brainstem encephalitis with positive findings on head MRI--case report].

We report a case of Bickerstaff's brainstem encephalitis (BBE) with positive findings on head MRI. Abnormal lesions on head MRI were detected in approximately 30% cases of BBE. An 81-year-old female presented with disturbance of consciousness (Japan Coma Scale 200), ophthalmoplegia (downward deviation) and tetraplegia. Cerebrospinal fluid examination revealed mild pleocytosis 244 cells in 3 microl of CSF with normal glycorrhachia. Head MRI showed high-intensity abnormalities extending over the brain stem. The patient was diagnosed with BBE. It was thought that her symptoms were believed to arise from the lesion in reticular formation, rostral interstitial nucleus of the medial longitudinal fasciculus, and the pyramidal tract. At discharged after 1 month, she had no sequela.

Development of an ultrasound system for measuring tissue strain of lymphedema.

This paper develops a portable measurement system for tissue strain distribution using ultrasonic pulse echo method. A single element ultrasonic transducer attached to a force sensor compresses biological tissue and observes the deformation process of the tissue. The center frequency of the ultrasound pulse is 3 MHz. The force applied to the tissue is kept at 10 N by an internal coil spring. Received echo signals are transferred to a personal computer via Universal Serial Bus. The developed measurement system was applied to measuring strain of subcutaneous fat for lymphedema patients and healthy subjects. The results quantified the fact that affected tissue becomes harder than unaffected tissue. Our experiment demonstrated that the system can be used for evaluating the condition of lymphedema with measurement of strain in subcutaneous tissue.

Recurrent intracranial solitary fibrous tumor initially diagnosed as hemangiopericytoma.

We describe a case of an intracranial solitary fibrous tumor that recurred three times consecutively in an 11-year period. A 72-year-old man presented with a headache and gait disturbance. Magnetic resonance imaging (MRI) revealed a dumbbell tumor at the left tentorium. The tumor was removed but recurred. The first diagnosis was hemangiopericytoma, but all specimens showed a "patternless pattern" and few reticulin fibers, which features were not compatible with hemangiopericytoma. All tumors showed immunoreactivity for CD34 and bcl-2. These results point to a solitary fibrous tumor (SFT) and not to hemangiopericytoma. We present here a hypercellular spindle-cell tumor that was very similar to hemangiopericytoma but is better diagnosed as SFT.

Characteristics of helmet or knit cap use in head injury of snowboarders.

The rate of head injury is 1.86-6 times higher for snowboarding than for skiing. Detailed data about the usefulness of a helmet or knit cap for protecting against serious head injuries have not been reported. The present study evaluated the use of a helmet or knit cap for preventing head injuries. Questionnaire data were collected from 1,190 consecutive patients in a hospital during the 1999/2000-2002/2003 winter seasons at Uonuma ski resort, Niigata, Japan. Patients were divided into the helmet, knit cap, and no cap groups. Upper technical level was highest and jumping as the cause of injury was most frequent in the helmet group. After adjustment for other confounders, there was a significant negative association between the occurrence of serious head injury during snowboarding and female sex (adjusted odds ratio 0.55, 95% confidence interval 0.421-0.718, p < 0.0001) and a significant positive association between serious head injury and jumping (adjusted odds ratio 2.25, 95% confidence interval 1.48-3.43, p = 0.0001). Among snowboarding maneuvers, only jumping showed a significant negative association between wearing of a helmet or knit cap and the occurrence of serious head injury (p = 0.036). Snowboarders who wear helmets might attempt dangerous maneuvers causing injuries. Wearing of a helmet or knit cap protected against serious head injuries on jumping. Every snowboarder should wear a helmet or knit cap on jumping to prevent head injury.

Automated discrimination of tissue boundaries using ultrasound images of "ubiquitous echo".

Balance between human body compositions, e.g. bones, muscles, and fat, is one of the major and basic indicators related to personal health. Body composition analysis using ultrasound imaging has developed rapidly. However, interpretation of ultrasound images is conducted manually, and accuracy and confidence in interpretation requires experience. This paper proposes an automated approach to determine boundaries between tissues, with which thickness of subcutaneous fat and muscles can be obtained. A portable B-mode ultrasound echographic device, which is called Ubiquitous Echo, was used in this study. The validity of the proposed method was evaluated in eleven subjects (three women, eight men; ages 22-77 yr) at three anatomical sites. Experimental results show that the proposed method can achieve considerably high discrimination performance.