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We developed an effective hemostatic method using Hydrofit® and a hemostatic gelatin sponge (Spongel®). We evaluated the hemostatic effect in comparison to the conventional silicone sheet method. A simulated circuit was created using the pump of a Nipro ventricular assist system and a prosthetic graft. A hole was made in the graft by a needle and three hemostatic methods were applied: the silicone sheet method (SS) using Hydrofit® and a silicone sheet, the bread and butter method (BB) using Hydrofit® and a gelatin sponge instead of a silicone sheet, and French toast method (FT) using Hydrofit® and a gelatin sponge over which water was poured before compression. The amount of leakage before and after the application each of the methods was measured according to the compression time. In the 60 s compression, the amount of leakage after SS, BB, and FT was 0.4 ± 0.8, 0.2 ± 0.6, and 0 ± 0.0 ml, respectively, and FT showed no leakage. In the 30 s compression, the amount of leakage after SS, BB, and FT was 14.2 ± 27.9, 1.0 ± 3.2, and 7.8 ± 22.6 ml, respectively, and did not differ to a statistically significant extent. The method of combining Hydrofit® and Spongel® could obtain reliable hemostasis in 60 s.

We developed a surgical hemostatic film using Hydrofit® (Hydrofit® film). This film is prepared by reacting Hydrofit® with water in advance, and it can be used in the same way as an accessory silicone sheet. In addition, unlike the silicone sheet, there is no need to remove the Hydrofit® film from the body. In the present study, we describe the hemostatic effect of our new method using Hydrofit® film. We created a pulsatile flow circuit model using a ventricular assist device and a vascular graft. The circuit was filled with water, and the systolic pressure was adjusted to ≥ 130 mmHg. The artificial blood vessel was punctured by an 18-G needle. Operations to prevent water from leaking were attempted through either a conventional method using a silicone sheet or our new method using Hydrofit® film. In the 180-s trial, 14 attempts (93.3%) with the Hydrofit® film were successful. In the silicone sheet group, 13 attempts (86.7%) were successful before the silicone sheet was peeled off, and hemostasis was maintained in 10 (66.5%) cases after the silicone sheet was removed. After short-duration hemostasis for 60 s, good waterproofing was obtained in the Hydrofit® film group (success in 17 cases [85%]). In contrast, in the silicone sheet group, 10 attempts (50%) were successful before the silicone sheet was peeled off, and hemostasis was maintained in only 7 (35%) cases after the silicone sheet was removed. Hydrofit® film showed good hemostatic performance in the pulsatile flow circuit model.

Background: In many developed countries, mood disorders have become problematic, and the economic loss due to treatment costs and interference with work is immeasurable. Therefore, a simple technique to determine individuals’ depressive state and stress level is desired. Methods: We developed a method to assess specific the psychological issues of individuals with major depressive disorders using emotional components contained in their voice. We propose two indices: vitality, a short-term index, and mental activity, a long-term index capturing trends in vitality. To evaluate our method, we used the voices of healthy individuals (n = 14) and patients with major depression (n = 30). The patients were also assessed by specialists using the Hamilton Rating Scale for Depression (HAM-D). Results: A significant negative correlation existed between the vitality extracted from the voices and HAM-D scores (r = −0.33, p &lt, 0.05). Furthermore, we could discriminate the voice data of healthy individuals and patients with depression with a high accuracy using the vitality indicator (p = 0.0085, area under the curve of the receiver operating characteristic curve = 0.76).

In many developed countries, mental health disorders have become problematic, and the economic loss due to treatment costs and interference with work is immeasurable. Therefore, we developed a method to assess individuals’ mental health using emotional components contained in their voice. We propose two indices of mental health: vitality, a short-term index, and mental activity, a long-term index capturing the trends in vitality. To evaluate our method, we used the voices of healthy individuals (n = 14) and patients with major depression (n = 30). The patients were also assessed by specialists using the Hamilton Rating Scale for Depression (HAM-D). A significant negative correlation existed between the vitality extracted from the voices and HAM-D scores (r = -0.33, p < .05). We could discriminate the voice data of healthy individuals and patients having depression with a high accuracy using the vitality (p = .0085, area under the curve = 0.76). Further, we developed a method to estimate stress through emotion instead of analyzing stress directly from voice data. By daily monitoring of vitality using smartphones, we can encourage hospital visits for people before they become depressed or during the early stages of depression, to prevent adverse consequences of depression.

Background: In many developed countries, mental health disorders have become a problem, and the economic loss due to treatment costs and interference with work is immeasurable. Therefore, a simple technique must be developed to determine individuals’ depressive state and stress levels. Voice analysis using smartphones is not only noninvasive, it does not require a dedicated device; thus, it can be performed conveniently and remotely. Consequently, we developed a method to assess individuals’ mental health levels using emotional components contained in the human voice. Methods: We proposed two indices of mental health: a short-term index (vitality) and mental activity calculated from long-term trends in vitality. We used the voices of healthy individuals (men: n = 10, Mage = 42.7 ± 6.0 years; women: n = 4, Mage = 35.0 ± 14.4 years) and patients with major depression (men: n = 19, Mage = 43.7 ± 11.0 years; women: n = 11, Mage = 53.9 ± 8.2 years). For patients, simultaneously with voice collection, specialists assessed current depression severity using the Hamilton Rating Scale for Depression (HAM-D). Results: A significant negative correlation existed between the vitality extracted from voice and HAM-D score (r = -0.33, p < .05). We could discriminate the voice data of healthy individuals and patients with depression (judged as moderate or severe by the specialists) with high accuracy using vitality (p = .0085, the area under the curve (AUC) of the receiver operating characteristic curve = 0.87). However, there was no significant difference between the vitality of the healthy individuals and the patients judged to be the “no depression group with almost no depressive symptoms,” even if they were outpatients with depression (p > .1, AUC = 0.64). Conclusions: We developed a method to estimate stress through emotion instead of analyzing stress directly from voice data. By daily monitoring of vitality using smartphones, we can encourage hospital visits for people before they become depressed or during the early stages of depression. This may lead to reduced economic loss due to treatment costs and interference with work.

Mental health disorder is becoming a social problem, and there is a need for technology that can easily check for states of stress and depression as a countermeasure. Conventional methods of diagnostic support and screening include self-administered psychological tests and use of biomarkers. However, there are problems such as burden on subjects, examination costs, dedicated reagents and equipment required for examinations, and reporting bias. On the other hand, voice-based evaluations are advantageous in terms of providing diagnostic support for physicians. They are non-invasive, do not require special and exclusive equipment, and can therefore be easily conducted remotely. We are pursuing the research and development of the Mind Monitoring System (MIMOSYS), which estimates the state of mental health from voice. Recorded audio is often compressed for efficient storage and transmission. However, there are concerns regarding the effects of deterioration of sound quality on analysis by MIMOSYS. Therefore, this study aims to verify the influence of the deterioration of voice quality due to coding on MIMOSYS analysis. As a verification experiment, coding was applied on the recording of 704 subjects reading 17 fixed phrases, assuming compression for transmission and storage. Then, the results of MIMOSYS analysis before and after encoding were compared. A strong correlation was observed before and after encoding, suggesting that MIMOSYS analysis is also valid for voice to which coding was applied.

We propose the use of the pitch rate of free-form speech recorded by smartphones as an index of voice disability. This research compares the effectiveness of pitch rate, jitter, shimmer, and harmonic-to-noise ratio (HNR) as indices of voice disability in English, German, and Japanese. Normally, the evaluation of these indices is performed using long-vowel sounds; however, this study included the recitation of a set passage, which is more similar to free-form speech. The results showed that for English, the jitter, shimmer, and HNR were very effective indices for long-vowel sounds, but the shimmer and HNR for read speech were considerably worse. Although the effectiveness of jitter as an index was maintained for read speech, the pitch rate was better in distinguishing between healthy individuals and patients with illnesses affecting their voice. The read speech results in German, Japanese, and English were similar, and the pitch rate showed the greatest efficiency for identification. Nevertheless, compared to English, the identification efficiency for the other two languages was lower.

We have been developing a method of evaluating the mental health condition of a person based on the sound of their voice. Currently, we have applied this technology to create a smartphone application that shows the vitality and the mental activity as mental health condition indices. Using voice to measure one’s mental health condition is a non-invasive method. Moreover, this application can be used continually through a smartphone call. Unlike a periodic checkup every year, it could be used for monitoring on a daily basis. The purpose of this study is to compare the vitality index to the widely used Beck depression inventory (BDI) and to evaluate its validity. This experiment was conducted at the Center of Innovation Program of the University of Tokyo with 50 employees of one corporation as participants between early December 2015 and early February 2016. Each participant was given a smartphone with our application that recorded his/her voice automatically during calls. In addition, the participants had to read and record a fixed phrase daily. The BDI test was conducted at the beginning of the experimental period. The vitality index was calculated based on the voice data collected during the first two weeks of the experiment and was considered as the vitality index at the time when the BDI test was conducted. When the vitality and the mental activity indicators were compared to BDI score, we found that there was a negative correlation between the BDI score and these indices. Additionally, these indices were a useful method to discriminate a participant of high risk of disease with a high BDI score. And the mental activity index shows a higher performance than the vitality index.

We developed an effective hemostatic method using HydrofitA simulated circuit was created using the pump of a Nipro ventricular assist system and a prosthetic graft. A hole was made in the graft by a needle and three hemostatic methods were applied: the silicone sheet method (SS) using HydrofitIn the 60 s compression, the amount of leakage after SS, BB, and FT was 0.4 ± 0.8, 0.2 ± 0.6, and 0 ± 0.0 ml, respectively, and FT showed no leakage. In the 30 s compression, the amount of leakage after SS, BB, and FT was 14.2 ± 27.9, 1.0 ± 3.2, and 7.8 ± 22.6 ml, respectively, and did not differ to a statistically significant extent.The method of combining Hydrofit

We developed a surgical hemostatic film using Hydrofit

The number of publications concerned with typical bulk-heterojunction solar cells that use fullerene derivatives and inorganic materials as electron acceptors has grown very rapidly. In this work, we focus on Ti-alkoxides as electron acceptors in the photoactive layers of fullerene-free bulk-heterojunction solar cells. We show that it is possible to control the morphology by adjusting the molecular structure and size of the Ti-alkoxides. The short-circuit current density ( J sc ) increased to 191 μA/cm 2 from 25 μA/cm 2 with a maximum, when the phase-separation structure was continuously formed to within about 20 nm below the exciton diffusion length by using either titanium(IV) ethoxide or isopropoxide as an electron acceptor. Within a thickness of 30 nm, the photoactive layer is not influenced by the electron transfer ability; thus, we demonstrate that the charge-separation efficiency is equivalent to that of a fullerene system.

Dealing with sleep apnea syndrome (SAS) is important because of its social burden, however current standard diagnosis requires a costly examination (polysomnography, PSG). Therefore, strong demand for easy screening methods for SAS exists. There is also a need for evaluation of therapeutic effect by continuous positive airway pressure (CPAP). Because CPAP requires adjustment of parameters (titration), or CPAP used inadequately will not improve a patient’s symptom. Considering quality of life, evaluation of therapeutic effect requires monitoring of mental and physical conditions in daytime. We already reported that mental healthiness evaluated from voice, called “vitality,” showed some correlation with severity of SAS. In this study we examined feasibility of vitality as an index of therapeutic effect by CPAP. We recorded voices from subjects when they were examined by PSG for first diagnosis and titration, before and after each examination. Then we evaluated vitality of the subjects at the recording. The subjects were categorized into two groups; subjects of a group started using CPAP after titration, and subjects of another group started using CPAP before titration. As results, direction of change in vitality in the former group varied by subjects at titration, while vitality in the latter group showed tendency of improvement. Within the latter group, the change in vitality tends to get larger as usage rate of CPAP before titration is higher. This result suggests that vitality has a potential for an easy method to evaluate therapeutic effect for SAS, and that diligence of CPAP usage is important for effective treatment.

Mental health disorders have become a social problem, and countermeasures are thus required. Previously, the authors developed the MIMOSYS (Mind Monitoring System) algorithm to evaluate an individual’s mental health state using their voice. An individual’s mental health state is detected using aspects of emotions that are present in their voice; however, since emotions change subtly, influence to emotions will be concerned owing to voice acquisition methods such as a natural conversation with someone else or reading fixed phrases. The aim of this research was to evaluate the influence of the type of voice acquisition method on the estimation of emotion and mental health state using the vocal analysis in MIMOSYS. In the experiments, we collected emotions and MIMOSYS analysis results from voice recordings during calls and during readings of fixed phrases from the application for over two weeks. In addition, the Beck’s Depression Inventory (BDI) test was used to evaluate participants’ subjective depression levels at the beginning of the experiment. In the evaluation, we analyzed recordings of calls and readings of fixed phrases for the participants in the normal range of the BDI test. Results indicated that the expression of emotions was suppressed in the recordings of readings of fixed phrases when compared to the recordings of calls, and the analysis result by MIMOSYS tended to be lower. Consequently, when measuring an individual’s mental health state from their voice, it may be necessary to match the type of voice acquisition methods or correct the estimations according to acquisition method.

As the age of the human population increases worldwide, depression in elderly patients has become a problem in medical care. In this study, we analyzed voice-emotion component data, attribute data, and Beck Depression Inventory (BDI) scores by multivariate analysis, particularly in the elderly, and proposed evaluation indicators for estimating the state of depression of elderly patients. We divided the data into two groups according to BDI scores: a state of depression and the absence of this state. The labels distinguishing the two groups were dependent variables, while the voice-emotion component and attribute information were set as independent variables, and we performed logistic regression analysis on the data. We obtained a prediction model with significantly sufficient fitness. In the receiver operating characteristic curve for the proposed depression evaluation indicator, a sorting performance with an area under the curve of approximately 0.93 was obtained.

Mental health disorder has become a problem in many developed countries and in order to cope with it, a screening technology that will help to check depression and stress is being sought. The authors conducted research into estimating health status from the voice in a previous study, and have developed the MIMOSYS (Mind Monitoring System). The recorded voice might compress for efficiently transmitting or store the voice, so it is possible for sound quality deterioration caused by the coding of the voice to impact the results of the MIMOSYS analysis. The degradation of sound quality due to audio compression is performed by general signal quality evaluation, e.g. Peak Signal-to-Noise Ratio (PSNR) and mean opinion score (MOS). However, it is necessary to individually evaluate the impact on the health indicator based on the voice features. The purpose of this study is to verify the impact of voice sound quality degradation by compression on health state evaluation using voice. In the experiment, we used recorded voice of the 979 subjects of reading 17 fixed phrases, and AAC/MP3/WMA coding was applied assuming compression when recording and archiving. Here, the average PSNR square wave between original wave format file and compressed files with an AAC, MP3, and WMA coding were 29.58dB, 55.96dB, and 29.58dB. The audio before and after compressing was analyzed to compare the degree of health by correlation evaluation. The results show that there is a strong correlation between before and after compression, suggesting the possibility of using compressed audio for health state evaluation using voice.

In stressful modern society, mental health care is one of important issues. The authors have been developing methods to assess mental health status by voice. Analysis using voice has benefits such as, noninvasive, not necessary any specialized device, easy use, and remote-able monitoring. We focused on the pattern of voice frequency during in daily life telephone calls, and developed the Mind Monitoring System (MIMOSYS) which is the smartphone application to monitor the mental health status by voice during telephone calls. MIMOSYS uses voice emotion recognition technology (ST: Sensibility Technology) and outputs “Vitality” which is the indicator to denote the health status immediately after the telephone call and “Mental Activity” which is the indicator to denote the mid-to long-term health status. Higher vitality and Mental Activity values represent a better mental health status. We expect that the user can avoid behavior mental condition due to inducing behavior change, for example depression state, by monitoring mental health status daily using MIMOSYS. When using MIMOSYS, it is desirable to avoid noise as much as possible during telephone calls because empirically at least 7 utterances or more are appropriate for calculating the vitality and it is difficult to correctly detect utterances if noise is contained in the voice. However, environmental sounds will be included when talking in a hands-free manner, and it may cause analyzed results of incorrect mental health status because of unreliable vitality. In this study, we investigate the impact of various noises on the mental health status output by our voice analysis method. We used the sound corpus CENSREC-1-C provided by Speech Resources Consortium in the experiment. This corpus consists of two kinds of data, the simulated data by the noise-addition and the recording data in real environments. One voice data is a numeric string vocalized with several intervals and includes nine or ten utterances. The simulated data includes eight kinds of noise, such as Subway, Babble, Car, Exhibition, Restaurant, Street, Airport and Station. In each noisy environment, noises at SNRs from 20dB to −5dB every 5 dB increments are artificially added to clean voice data without noise. The number of speaker is 104 in this data set. The real environmental data includes two real-noisy environments, such as the university restaurant and the vicinity of highway. In each real environment, there are two SNR conditions, the lower and higher SNR conditions. Furthermore, voice data was recorded with close microphone and remote microphone synchronously in real environments. The number of speaker is 10 in this data set, Voice analysis was performed for both voice data sets. We used only “vitality” for this research because the data have only one time point data. As a result for the simulated data, the mean of vitality values for voice data at SNR of 20dB was lower than it for clean voice data in each environment, and the means of vitality values for voice data at noise levels noisier than 20dB tended to show higher values in five environments (Car, Restaurant, Street, Airport and Station). As a result for the real environmental data, the mean of vitality values for voice data recorded with remote microphone was higher than it with close microphone in any combination of two noisy environments and two SNR conditions. On the other hand, utterances detected in the voice analysis were almost correctly detected for clean voice data and voice data at SNR of 20dB in all environments in the simulated data, but the detection accuracies at noise levels noisier than 20dB were poor markedly. The similar trend was shown in the real environmental data, that is, the detection accuracy of utterances for voice data recorded with remote microphone was poor markedly in any combination of two noisy environments and two SNR conditions. This means that a noise part is incorrectly recognized as an utterance and the voice analysis is performed including the false utterance. Therefore, it is possible that the mental health status cannot be calculated correctly under noisier environments. From the above results, the noisy environment at SNR of about 20dB is the limit of the analysis under some noise. Moreover, changes of emotions calculated by ST were also investigated in the simulated data. As a result, the means of joy and sorrow components of voice data at SNR of 20dB were higher than these means of clean voice data in all noisy environments, and the mean of anger component of voice data at SNR of 20dB was lower than that mean of clean voice data in all noisy environments. This indicates that not only the speech detection but also the noise itself affects the analysis result of the mental health status. In the future, we will increase the accuracy of utterance detection under noise environment and verify that the accuracy of mental health status analysis will improve with an appropriate noise filter.

The purpose of this study is to verify the impact of a deterioration of the sound quality of voice by a telephone line on estimating Vitality as the extent of depressive tendency based on voice analysis using MIMOSYS. First, the voices of about 1,000 people recorded using a recorder were prepared. Next, each voice was coded and resampled in preparation for transmission over a phone line. Vitalities obtained by analyzing the voices before and after these processes were compared. The results showed high correlation between the Vitality after coding and Vitality before coding, revealing that using a telephone would be an effective way to obtain voices.

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting material. However, fullerene derivatives are air-sensitive; therefore, air-stable material is needed as an alternative. In the present study, we propose and describe the properties of Ti-alkoxide as an alternative electron-accepting material to fullerene derivatives to create highly air-stable BHJ solar cells. It is well-known that controlling the morphology in the photoactive layer, which is constructed with fullerene derivatives as the electron acceptor, is important for obtaining a high overall efficiency through the solvent method. The conventional solvent method is useful for high-solubility materials, such as fullerene derivatives. However, for Ti-alkoxides, the conventional solvent method is insufficient, because they only dissolve in specific solvents. Here, we demonstrate a new approach to morphology control that uses the molecular bulkiness of Ti-alkoxides without the conventional solvent method. That is, this method is one approach to obtain highly efficient, air-stable, organic-inorganic bulk-heterojunction solar cells.

The effect of formic acid and citric acid surface modification on the bonded strength of the solid-state direct bonded interface of copper was investigated by SEM observations of interfacial microstructures and fractured surfaces. Copper surfaces were modified by boiling in 98% formic acid for 0.6 ks and 17% aqueous solution of citric acid for 0.96 s. Solid-state bonding was performed in a vacuum chamber at bonding temperature of 423 ~ 673 K under a pressure of 588 N (bonding time of 0.9 ks). As a result of surface modification by formic acid and citric acid, bonded joints were obtained at a bonding temperature 150 K (formic acid) and 100 K (citric acid) lower than that required for non-modified surfaces, and the bond strength was comparable to that of the maximum load.

We have developed pitch rate (pitch detection ratio) in the speech segment as a voice disability index for use in free form speech data from smartphones. Its performance was compared with jitter, shimmer, and harmonic to noise ratio (HNR) indices. Conventionally, the performance of these indices is evaluated using long vowel sounds, but in this study we used the read speech of “Rainbow passage”. As a result, although jitter, shimmer, HNR displayed good performance for long vowel sounds, for the read speech data, performance of shimmer and HNR was significantly low. However, although jitter performed comparatively well for read speech, pitch rate was found to be a better indicator for voice disability between patients and healthy individuals.

Objective: In this study, we propose a voice index to identify healthy individuals, patients with bipolar disorder, and patients with major depressive disorder using polytomous logistic regression analysis.Methods: Voice features were extracted from voices of healthy individuals and patients with mental disease. Polytomous logistic regression analysis was performed for some voice features.Results: With the prediction model obtained using the analysis, we identified subject groups and were able to classify subjects into three groups with 90.79% accuracy.Conclusion: These results show that the proposed index may be used as a new evaluation index to identify depression.

Article, PSYCHIATRY AND CLINICAL NEUROSCIENCES. 62(3): 286-292(2008)

Das mehrdimensionale Feld der Fahrdynamik bietet eine Vielfalt an Interpretationen, wie der Kunde sich ein Fahrzeug wunschen wurde. Im Spannungsfeld zwischen den Emotionen der Kunden und den erforderlichen Zahlen und Fakten fur Ingenieure bietet die Anwendung der abgesicherten Methode Quality Function Deployment (QFD) ein effektives Hilfsmittel der Ubersetzung. TUV Sud Automotive hat gemeinsam mit der Toyota Motor Corporation mit der Methode „Improve by QFD“ die Kundenwunsche am Beispiel Lenkverhalten nach statistischen Grundsatzen aufgenommen, in Zielwerte fur die entwickelnden Ingenieure weiterverarbeitet, in einem Fahrzeugprototyp umgesetzt und final die Erfullung der Kundenwunsche erfolgreich verifiziert.

The multi-dimensional field of driving dynamics offers a multitude of interpretations of the type of vehicle the customer would wish for. Between the two poles customer’s emotions and facts and figures required by engineers, the application of the method “Quality Function Deployment” (QFD) is intended as an effective tool for translation. TUV Sud Automotive captured together with Toyota Motor Corporation with the method “Improve by QFD” the customer’s wishes at the example steering behavior according to statistical principles, translated these information into target parameters for the R&D engineers, realized them in a prototype vehicle and finally validated the fulfillment of the customer’s expectations successfully.

We are developing a high-performance brain PET scanner, jPET-D4, which provides 4-layer depth-of-interaction (DOI) information. The scanner is designed to achieve not only high spatial resolution but also high scanner sensitivity with the DOI information obtained from multi-layered thin crystals. The scanner has 5 rings of 24 detector blocks each, and each block consists of 1024 GSO crystals of 2.9 mm/spl times/2.9 mm/spl times/7.5 mm, which are arranged in 4 layers of 16/spl times/16 arrays. At this stage, a pair of detector blocks and a coincidence circuit have been assembled into an experimental prototype gantry. In this paper, as a preliminary experiment, we investigated the performance of the jPET-D4's spatial resolution using the prototype system. First, spatial resolution was measured from a filtered backprojection reconstructed image. To avoid systematic error and reduce computational cost in image reconstruction, we applied the DOI compression (DOIC) method followed by maximum likelihood expectation maximization that we had previously proposed. Trade-off characteristics between background noise and resolution were investigated because improved spatial resolution is possible only when enhanced noise is avoided. Experimental results showed that the jPET-D4 achieves better than 3 mm spatial resolution over the field-of-view.

A high-performance brain PET scanner, jPET-D4, which provides four-layer depth-of-interaction (DOI) information, is being developed to achieve not only high spatial resolution, but also high scanner sensitivity. One technical issue to be dealt with is the data dimensions which increase in proportion to the square of the number of DOI layers. It is, therefore, difficult to apply algebraic or statistical image reconstruction methods directly to DOI-PET, though they improve image quality through accurate system modelling. The process that requires the most computational time and storage space is the calculation of the huge number of system matrix elements. The DOI compression (DOIC) method, which we have previously proposed, reduces data dimensions by a factor of 1/5. In this paper, we propose a transaxial imaging system model optimized for jPET-D4 with the DOIC method. The proposed model assumes that detector response functions (DRFs) are uniform along line-of-responses (LORs). Then each element of the system matrix is calculated as the summed intersection lengths between a pixel and sub-LORs weighted by a value from the DRF look-up-table. 2D numerical simulation results showed that the proposed model cut the calculation time by a factor of several hundred while keeping image quality, compared with the accurate system model. A 3D image reconstruction with the on-the-fly calculation of the system matrix is within the practical limitations by incorporating the proposed model and the DOIC method with one-pass accelerated iterative methods.

A high-performance positron emission tomography (PET) scanner, which measures depth-of-interaction (DOI) information, is under development at the National Institute of Radiological Sciences in Japan. Image reconstruction methods with accurate modeling of the system response functions have been successfully used to improve PET image quality. It is, however, difficult to apply these methods to the DOI-PET scanner because the dimension of DOI-PET data increases in proportion to the square of the number of DOI layers. In this paper, we propose a compressed imaging system model for DOI-PET image reconstruction, in order to reduce computational cost while keeping image quality. The basic idea of the proposed method is that the DOI-PET imaging system is highly redundant. First, DOI-PET data is transformed into compact data so that data bins with highly correlating sensitivity functions are combined. Then image reconstruction methods based on accurate system modeling, such as the maximum likelihood expectation maximization (ML-EM), are applied. The proposed method was applied to simulated data for the DOI-PET scanner operated in 2-D mode. Then the tradeoff between the background noise and the spatial resolution was investigated. Numerical simulation results show that the proposed method followed by ML-EM reduces computational cost effectively while keeping the advantages of the accurate system modeling and DOI information.

A 40-year-old woman was admitted with altered consciousness and hyperammonemia after she had delivered her first baby. DNA analysis of the citrin gene and enzymatic assay of argininosuccinate synthetase in the liver led to a diagnosis of adult-onset type II citrullinemia (CTLN2). She was also found to have hepatocellular carcinoma (HCC) and underwent palliative surgery consisting of partial liver section of the HCC. Delivery may be a trigger for the development of CTLN2, while certain pathologic conditions associated with citrin gene abnormality are likely to induce hepatocellular carcinoma in patients with this disorder.

A recent method "wavelet analysis" is applied as a tool for analyzing time sequential quantities derived from chaotic systems. As typical examples, the present method is applied to two well known systems, the Lorenz model and the Rossler model. The main procedure consists of calculating the local cross correlations between the signal to be analyzed and a predefined waveform called a "wavelet" at various time scales. This makes it possible to unfold the signal into both time and frequency, whereas in Fourier analysis, results are obtained in the frequency domain. The present paper mainly focuses on understanding the properties of this method, and shows a way to interpret the results.

In this study, the effect of the metal salt generation bonding technique on the strength of a direct-bonded copper–copper interface was investigated. Copper surfaces were modified by boiling in several types of organic acids, and direct bonding was performed at a bonding temperature of 423–673 K under a load of 588 N (for a bonding time of 0.9 ks). As a result of the surface modification, bonded joints were obtained at bonding temperatures of 150 K (after treatment with formic acid) and 100 K (after citric acid treatment) lower than that required for the unmodified surfaces. In addition, the duration of the modification effects was investigated by exposing the modified surface to an air atmosphere furnace kept at 323 K. The bonding strength of the citric acid-modified surface remained unchanged even after 168 h, whereas that of the surface modified with formic acid decreased within 6 h.

We proposed a unique motion detection method that can be used for motion correction in brain PET imaging. This method uses a specially-designed solid marker that enables position and angle (direction) measurement with one optical movie camera. Therefore, it is applicable to a long, narrow patient port space in which a two-camera system cannot be installed. By refining machining accuracy of the solid marker, angle measurement accuracy was significantly improved. As a result, we obtained sufficient measurement accuracies in the angles as well as in the trans-axial positions. In addition, we have been developing a model to calculate axial positions from measured trans-axial positions and angles. As a result of a multivariate analysis of measured motion tracking data, we found that sufficient accuracy can be obtained under well-controlled experimental conditions. In order to realize head motion correction for jPET-D4, we are also considering marker attaching, camera calibration, device installation, and correction algorithms.

A novel four-layered depth-of-interaction (DOI) positron emission tomography (PET) scanner is being developed at National Institute of Radiological Sciences, Japan. It aims to improve the image resolution, particularly at the edge of field of view while maintaining high sensitivity. However, inter-crystal scatter (ICS) occurs in the detector blocks of the jPET-D4. It is a phenomenon where there are multiple scintillations for a single irradiation of gamma photon due to Compton scatter in detecting crystals. Because of the Anger-type logic calculation, only one approximated position is detected by the jPET-D4 in the case of ICS. This causes error in position detection and ICS worsens the image contrast, particularly for smaller hotspot. In this paper, we propose to model an ICS probability by utilizing a Monte-Carlo simulator. It is a statistical relationship between gamma-ray first interaction crystal pair and the detected crystal pair. The ICS probability is then used to improve the system matrix of statistical image reconstruction algorithm ML-EM in order to correct the error of ICS. We have shown in computer simulation that image contrast is recovered successfully by applying the proposed method.

A high-performance brain PET scanner, jPET-D4, which provides depth-of-interaction (DOI) information, is under development. The scanner is designed to achieve not only high spatial resolution but also high scanner sensitivity with the DOI information obtained from multi-layered thin crystals. The scanner has 5 rings of 24 detector blocks each, and the detector block consists of 1,024 GSO crystals of 2.9 mm/spl times/2.9 mm/spl times/7.5 mm, which are arranged in 4 layers of 16/spl times/16 arrays. At this stage, a pair of detector blocks and a coincidence circuit has been assembled into an experimental prototype gantry. In this paper, as a preliminary experiment, we have investigated the performance of the jPET-D4's inherent spatial resolution and noise characteristics using the prototype system. Spatial resolution and background noise were measured by using a line source and a uniform cylinder phantom respectively. To avoid systematic error and reduce computational cost in image reconstruction, the DOI compression (DOIC) method followed by the ML-EM with accurate system modeling, that we have previously proposed, was applied. Experimental results showed that the JPET-D4 achieves less than 3 mm spatial resolution over the field-of-view. Trade-off results between spatial resolution and background noise also promise an excellent performance of the scanner.

We present a preliminary study on the design of a high sensitivity small animal DOI-PET scanner: jPET-RD (for Rodents with DOI detectors), which will contribute to molecular imaging. The 4-layer DOI block detector for the jPET-RD that consists of scintillation crystals (1.4 mm x 1.4 mm x 4.5 mm) and a flat panel position-sensitive photomultiplier tube (52 mm x 52 mm) was previously proposed. In this paper, we investigate imaging performance of the jPET-RD through numerical simulations. The scanner has a hexagonal geometry with a small diameter and a large axial aperture. Therefore DOI information is expected to improve resolution uniformity in the whole field of view (FOV). We simulate the scanner for various parameters of the number of DOI channels and the crystal length. Simulated data are reconstructed using the maximum likelihood expectation maximization with accurate system modeling. The trade-off results between background noise and spatial resolution show that only shortening the length of crystal does not improve the trade-off at all, and that 4-layer DOI information improves uniformity of spatial resolution in the whole FOV. Excellent performance of the jPET-RD can be expected based on the numerical simulation results.

We compared postural sway parameters during a 1-minute quiet stance in 28 patients with idiopathic Parkinson's disease (PD) in off phase with those in 17 age-matched normal subjects and investigated differences in the sway parameters before and after unilateral pallidotomy in 16 PD patients. The PD patients showed larger sway area (SA) and longer total sway path length (SPL) compared with normal subjects. Total SPL after subtraction of tremor effect did not differ from that in normal subjects. The shift of the mean center of foot pressure (CFP) position from the first 30 seconds to the last 30 seconds showed that the CFP tended to move forward in PD patients compared with normal subjects and to move laterally more in PD patients than normal subjects, especially in those with less severity (Unified Parkinson's Disease Rating Scale, motor score < 40). After the operation, there was little change in either SA or lateral movement of CFP, but forward movement of CFP and total SPL tended to be normalized, along with an improvement of major parkinsonian symptoms. From these results, it is concluded that SPL elongation significantly involves tremor effect, forward movement of CFP in PD derives from basal ganglia dysfunction, and SA enlargement and large lateral movement of CFP may be caused partly by compensatory movements or by dysfunction outside the basal ganglia circuitry.

The next generation PET scanner named jPET-D4 is being carried out at the National Institute of Radiological Sciences (NIRS) in Japan. At this stage, we plan to apply the reconstruction techniques after the histogramming of list-mode data because it is easy to implement and has low computational cost. The jPET-D4 has 4 layers DOI detectors and it can obtain true list-mode data. However, the conventional histogramming technique is inapplicable to 4 layer DOI detectors, so in this paper we propose a new histogramming method which is suitable for the multi-layer DOI detector. In this method, DOI-PET list-mode data is transformed into sinogram with an accurate system model of the crystal block. We also applied the method to simulated data for the JPET-D4 scanner. Numerical simulation results show that the proposed method reduces sampling error effectively while keeping the advantage of DOI information, and the image quality of JPET-D4 is superior to a conventional nonDOI PET scanner.

We describe a patient with cutaneous polyarteritis nodosa (CPN) and a patient with nonsystemic vasculitic neuropathy (NSVN), both presenting mononeuritis multiplex. Patient 1 was a 50 year-old woman. She developed livedo reticularis, palpable purpura, and sensory disturbance of lower extremities. Laboratory examinations showed no abnormal findings except for slight elevation of ESR, CRP, and anti-nuclear antibody. Skin biopsy revealed vasculitis of small to medium sized arterioles in dermis and subcutaneous adipose tissue. Sural nerve biopsy revealed axonal degeneration of myelinated fibers and infiltration of polymorphonuclear cells and mononuclear cells around feeding arteries. From these findings, she was diagnosed as having CPN. She was treated with intravenous injections of methylprednisolone (1,000 mg/day) followed by oral prednisolone (40 mg/day), which had a limited effect. Addition of an immunosuppressive agent (azathioprine 50 mg/day) produced marked improvement in her clinical symptoms. However, azathioprine was discontinued because of liver injury. Then, we added cyclophosphamide which was as effective as azathioprine. Patient 2 was a 57 year-old man. He developed weakness of legs and sensory disturbance of lower extremities and trunk. Laboratory examinations showed no abnormal findings except for slight elevation of CRP and anti-nuclear antibody. Sural nerve biopsy revealed infiltration of inflammatory cells mainly consisting of mononuclear cells around small sized arterioles in the epineurium and severe loss of myelinated fibers. From these findings, he was diagnosed as having NSVN. Treatment with oral prednisolone (60 mg/day) and azathioprine (50 mg/day) improved his clinical symptoms. CPN is differentiated from NSVN by the existence of skin lesions and the type of inflammatory cells involved. However, these two diseases share common clinical features such as mononeuritis multiplex, absence of systemic organ involvement, no specific abnormal laboratory data, effectiveness of immunosuppressive therapy, and relatively good prognosis. We suggest that CPN and NSVN are included in the same category of nonsystemic vasculitis that can involve peripheral nerves and/or skin.

Coccolithophores are important microorganism for the carbon and sulfur cycles. Coccolithophores bloom was found on 3 October 2007 in Suruga Bay. The seasonal appearance of coccolithophores and the relationship between nutrients are as follows.1. Coccolithophores generally increased in spring and showed the maximum in May. In spring they distributed more offshore surfaces than coastal area. The whole cell density decreased in summer and became the peak in October. 2. The dominant species was Emiliania huxleyi. 3. Increase of coccolithophores at the forehead of stratification appeared after the bloom of small diatoms. As for the nutrients, phosphate and silicate were less than the half of saturation constant of diatoms, while nitrate still remained, of which concentration sufficient for coccolithophores to increase.

A high-performance PET scanner, which measures depth-of-interaction (DOI) information, is in progress at the National Institute of Radiological Sciences in Japan. Image reconstruction methods with accurate modeling of the system response functions have been successfully used to improve PET image quality. It is, however, difficult to apply these methods to the DOI-PET system because the dimension of DOI-PET data increases in proportion to the square of the number of DOI layers. In this paper, we propose a compressed imaging system model for DOI-PET image reconstruction, in order to reduce computational cost with keeping image quality. The basic idea of the proposed method is that the DOI-PET system is highly redundant. First, DOI-PET data are transformed into compact data so that data bins of which sensitivity functions highly correlate are combined. Then image reconstruction methods based on accurate system modeling, such as the maximum likelihood expectation maximization (NIL-EM), are applied. The proposed method was applied to simulated data for the DOI-PET operated in 2D mode. Then the trade-off between the background noise and the spatial resolution was investigated. Numerical simulation results show that the proposed method followed by ML-EM reduces computational cost effectively with keeping the advantages of the accurate system modeling and DOI information.

食道癌に対し新しい合併療法の試みとして, Cisplatin+Pepleomycin (以下本療法) を術前術後に投与してきたが, 今回は本療法の術前合併療法としての意義について検討した.対象症例は昭和60年8月31日までに本療法が施行され当科で切除された35例 (うち術前照射例4例を含む) である.本療法による術前の臨床的改善度は33%～50%であった.切除された主病巣の組織学的効果度は45.7%であり, 転移リンパ節105個の組織学的効果度は29.5%であった.術後本療法に関連する合併症として1例に急性腎不全がみられた.他には重篤な副作用はみられなかった.本療法は有効な合併療法と考えられる.今後投与量, 併用薬剤についてさらに検討する.