The Great east Japan earthquake and Tsunami that occurred on 11, March 2011, had a major impact on research in Japan. Many universities and research institutes also suffered extensive damage. Reconstruction and revitalization of the research and communities impacted by this disaster remains a national priority. The iPS cells, genetically modified organisms and mutants are important research resources and must be preserved safely to keep the continuity of research activity in Japan's science community. In Interuniversity Bio-Backup project, the core facility for cryopreservation of biological resources was settled to National Institute for Basic Biology to back up the biological materials for each researcher and 7 universities were set up as the initial contact sites for every researchers to cover all part of the country. Through this project, we are aiming to warrant the sustainable development of research activities in Japan.
Cryoprotective agents (CPAs) such as dimethyl sulfoxide (DMSO), glycerol, or ethylene glycol have been used for the cryopreservation of many types of cells. DMSO is the most effective CPA but shows cytotoxicity and can effect differentiation. Here we report that the novel polymeric CPAs having low toxicity and high efficiency for mammalian cells including stem cells. Carboxylated poly-L-lysine (COOH-PLL) showed higher cryopreservation efficiency for many types of cell than the conventional CPAs. In addition, mesenchymal stem cell monolayers were cryopreserved more effectively than with DMSO based cryoprotective solutions via slow or rapid freezing methods. These results indicate that these polymeric extracellular CPAs may replace current CPAs and the high viability after thawing and nonnecessity of serum ensure that these CPAs may be used in tissue engineering fields for the storage of tissue constructs.
Recent advances in tissue engineering have led to the development of various artificial tissues, such as cell sheets and organoids, which are now being used in clinical settings. The progress made in the clinical application of cell sheets is especially remarkable. However, prior preparation of these sheets is a complex process and is a burden to patients. Cryopreservation of artificial tissues in clinical settings may help overcome these limitations. We have successfully cryopreserved tissues/organs, such as chondrocyte sheets, pancreatic islets, and fetal anlagens, via vitrification methods, which was developed through the cryopreservation of mammalian early embryos. Furthermore, we have demonstrated that the presence of carboxylated poly-L-lysine is effective for the stabilization of the vitrified state of the solution, increasing the integrity and survival of the vitrified tissues. This report focuses on the current progress and perspectives in artificial tissue cryopreservation, which will play an essential role in next-generation regenerative medicine.
We have established a system for assembling scaffold-free cell constructs, through the development of an automated 3D bio-printer, which can fabricate 3D cell constructs such as liver, cartilage or blood vessels. Our next challenges were to prepare a lot of spheroids for clinical application and to develop cryopreservation techniques so that spheroids can be transported and preserved for long periods of time. In this study, we have cryopreserved spheroids by using commercially available cryopreservation solution.Preliminary studies consisted of freezing spheroids of various sizes of human dermal fibroblast for 1 week. Spheroids cryopreserved in PBS solution were not fused with each other, whereas spheroids in cryopreserved solution were started to fuse at 5days. And the improvement of cryopreserved method has reduced the fusion time from 5 to 3 days. In conclusion, it was suggested that spheroids can be frozen and used by improvement of cryopreserved method.
Heart regenerative therapy using pluripotent stem cells (PSC) is a promising strategy for patients with heart disease, but the inability to eliminate residual undifferentiated stem cells and generate highly purified cardiomyocytes in sufficient quantities has been a barrier to realizing this potential. Our previously established non-genetic purification method of cardiomyocytes using mitochondrial dye is efficient but not suitable to produce large-scale cardiomyocytes due to the usage of FACS (Nat Methods 2010). To overcome these problems, we developed a novel method for purifying the bulk of PSC-derived cardiomyocytes by focusing on glucose and lactate metabolism in cardiomyocytes and PSCs (Cell Stem Cell 2013). In addition, minute research of amino acids metabolic profiles in human PSCs allowed for clinical-grade purification of matured cardiomyocytes (in revision). Finally, we succeeded to efficiently make a large number of metabolically purified cardiomyocytes balls derived from human PSCs. These technologies will strongly boost regenerative medicine.
Three-dimensional tissue engineering for regenerative medicine is desired for serious organ diseases. Especially, liver is a central organ for metabolism in our body and is complicated structure. Therefore, liver tissue engineering is one of the most important and difficult themes. However, formation of thick tissue (>1mm) is still impossible, because oxygen consumption rate of hepatocytes is higher than the other organs' cells. Organ-scale scaffold having a template of blood vessel network was obtained by decellularization with detergent. The fineness of the network was the same as original liver, evaluated by 3D-CT. Template of blood vessel network was endothelialized with HUVEC and blood leakage was prevented. On the other hand, decellularized liver was recellularized with hepatocytes. Furthermore, this recellularized liver expressed liver-specific functions of hepatocytes in organ culture, and well metabolized ammonia during blood circulation. In conclusion, decellularized organ is effective scaffold in three dimensional tissue engineering.
Tissue organization is governed by self-assembly phenomenon. In tissue architecture, variety of heterogeneous cell population habitat autonomously in the proper regions and maintain their organization. In our previous studies, a multi-layered human skeletal muscle myoblast (HSMM) sheet regarded as a plate-shaped aggregate was prepared and co-incubated on heterogeneous cell population, such as human umbilical vein endothelial cells (HUVECs), human skeletal muscle fibroblasts (HSMFs) or human mesenchymal stem cells (HMSCs) etc., to quantitatively elucidate their behavior inside the HSMM tissue. Stereoscopic observation by confocal laser scanning microscopy with image processing revealed random or collective migration and habitat aggregation of heterogeneous cell population inside the HSMM sheet depending on their character of cell-cell connection and migration. After understanding heterogeneous cell behavior inside the HSMM sheet, modified method to construct multilayered HSMM sheet with uniform HUVEC network by stacking single HSMM sheets including pre-formed 2D HUVEC network was successfully established.
Living tissues are composed of cells and extracellular matrix (ECM). ECM controls not only cell adhesion but also cell assembly. We have developed cell accumulation technique, which allows construction of three-dimensional (3D) tissues via controlling cell-cell interaction by fabrication of ECM nanofilms on cell surfaces. The 3D-tissues containing networks of blood and lymph endothelial cells have been obtained by sandwich culture of these cells. When cancer cells were cultured on the surface of the 3D-tissues with capillary networks, invasion and intravasation phenomena of the cancer cells were observed depending on the characters of cancer cells. The 3D-tissues with capillary networks are expected to apply for predictive medicine of cancer at early stage.
A fetus in the utero had not been an object of a medical care until medical engineering progressed and became to be used in the field of perinatal medicine. All most all fetuses are monitored with cardiotocometer during labor and saved their lives by proper management in Japan. Congenital abnormalities of the fetus can be diagnosed by 2D and 3D ultrasound in utero. Fetuses with severe congenital abnormalities are treated properly not only after birth, but also in utero in some cases. Newborn babies are checked and monitored non-invasively thanks to medical engineering. Medical engineering have caused “revolution” in perinatal medicine, but still there is room for the improvements.
The skeletal formation of the foot is completed by 20 years of age. In order to promote the appropriate skeletal formation, it is necessary to evaluate it by combining physical exercises and the development of the muscles. In this study, we measured the lower limb muscle strength of children and carried out the follow-up study on the developmental process of the foot and on the state of the foot and toenail. Subjects were 1518 children from 3 to 12 years old.
The results of this study revealed that the development of lower limb muscle strength proceeded from the hip joint to the peripheral and that hip adductor muscle increased greatly for children from 5 to 8 years old, and the peripheral muscle do the same from 7 to 10 years old. The observation of the foot revealed that the hallux valgus of girls from 10 years old, increased significantly.
We investigated variations in a women's cognitive function during a time of pregnancy and childbearing. Volunteers were composed of 114 healthy women ranging in age from 23-43 years. Further, 79 were pregnant and 35 were not pregnant. We instructed the pregnant women to carry out five kinds of tests: simple reaction, SR; choice reaction, CR; working memory, WM; one card learning, OC; and divided attention, DA using card games through a cognitive function test called CogHealth, and compared them to a nonpregnant group. In the results of the four measurement tasks (SR, CR, WM, and DA), there were no significant differences across the three groups in the responses with the tasks. However, the response times relating to the OC learning in the postnatal women were significantly smaller, as contrasted with the times for the pregnant and the nonpregnant women (F(2,144)=4.248).
Wireless body area network (WBAN) is a wireless sensor network inside, on or around the human body, and is expected to be utilized in medical and health-care applications. Dynamic behavior of radio propagation channel is important information for design and characterization of WBAN system. Various factors simultaneously influence the channel responses, such as position and orientation of antennas, electromagnetic interaction antenna and human body, and obstruction by human body itself. Therefore, it is rather difficult to analyze the propagation mechanism of dynamic WBAN channel. This paper reports the development of simultaneous measurement system of MIMO channel response and body posture of dynamic WBAN channel. Body posture information is utilized to synthesize numerical phantom for electromagnetic simulation via computer animation software. Comparison between measurement and predicted channel responses is possible by using the system, and some examples will be presented.
In this talk, we discuss challenges in the design of networking protocols, especially protocols in physical layer (PHY), medium access control (MAC) layer, and network layer, which we face to realize diverse medical applications of wireless networks. We investigate the key requirements of medical applications and potential enabling technologies in PHY/MAC/network layer protocols. As a concrete application, we introduce real-time vital information monitoring of athletes and people playing sports, which can enhance training efficiency and also prevent injury and disease during sports activities. We present technical challenges that should be solved in order to realize real-time gathering of various sensing data from a large number of densely-located nodes with coordinated mobility. Some preliminary results on sensing and communication aspects are presented and discussed.
We have proposed an intruder detection method by using Multiple Input Multiple Output (MIMO) channel. Although the channel capacity on the MIMO transmission is severely degraded in time variant channels, we can take advantage of this feature MIMO Sensor applications. We have already proposed the channel estimation method using arbitrary amplitude and phase modulation schemes for MIMO sensor. Moreover, the basic performance by the proposed CSI estimation method is verified when considering the intruder detection by MIMO sensor. In this paper, we study try to estimation of e behavior patterns by MIMO sensor with using time correlation with a narrow-band FSK signal. We evaluated the variation of the time correlation with people behavior by experiment. It is shown that motion behavior patterns such as standing up, seating and rotation can be estimated by the time correlation function via the experimental results.
Implant wireless communication has been so far attracting much attention as a promising technology in health care and medical applications. In this paper, for realizing reliable and high-speed implant communication, we pay attention to ultra wideband (UWB) transmission. This paper develops a transmit diversity antenna whose size can be acceptable to implantable medical devices and investigate the performances of the developed diversity antenna based on a finite difference time domain (FDTD) method. Furthermore, we propose an implant communication system with the developed diversity antenna and demonstrate that our proposed system can improve the reliability of the implant communication.
In healthcare data radio system, it is essential to avoid the communication disconnection when the transmission signal bit error rate (BER) exceeds a specific value. When the BAN antenna is attached at wrist, the polarization characteristics will be varied significantly according to the antenna rotation angle caused by the arm-swing motion. In this paper, the BER characteristic of a weighted-polarization BAN antenna considering human walking motion is measured while the validity of the proposed antenna is verified. At first, a method of BER Over-The-Air (OTA) Testing is proposed, where a fading emulator is utilized for realizing the actual propagation environment. Then, the BER measurement is carried out in considerations of the arm-swing motion using a human phantom. Compared with the conventional antenna, less SNR is required when the weighted-polarization BAN antenna is used to obtain the desired BER, indicating the effectiveness of proposed weighted-polarization antenna for BAN wireless applications.
Conventional microdevices are made of substrates having thicknesses relatively greater than the feature scale of the microfabricated components. In contrast, the microscale natural creatures are made of membranes, that are relatively thin compared to their feature size. Inspired by the fact, we have been developing 3-D microdevices composed of thin membranes. The small thickness of the membrane enhances transport between the inside of the device and its surroundings, and it also provides softness to the structure, enabling passive and active morphological changes. These characteristics of thin-membrane microdevices are suitable for biological and medical applications. In this talk, 3-D microfabrication process of thin polymer membrane and its application to biomedical devices are presented.
A high intensity focused ultrasound (HIFU) field of a transducer for ultrasound therapy was visualized using an image subtraction Schlieren technique. The transducer of 110 mm in diameter and 100 mm in focal length was driven by a burst pulse of 1.58 MHz in center frequency and of 10 W in input electric power. Figure 1 shows beam profiles on the acoustic axis. A FWHM of the beam was 5.8 mm in a visualized field and was 7.3 mm in a field determined by hydrophone measurement.
Since ultrasonography has insufficient performance in depicting the vertebral surface, most examiners perform epidural anesthesia using landmarks on the back without ultrasonography. The final purpose of this study is to improve the performance by ultrasonography in depicting thoracic vertebral surface.RPM method is one of the bi-static imaging methods, it estimates the reflection point on a target surface by intersections of plural ellipses, where the focal points of an ellipse are the position of a transmit element and that of a receive element.We investigated the performance of the RPM method in an experimental study using a phantom with a concave surface of a 2 cm curvature radius. The depicted region of concave surface acquired using the conventional method and the RPM method was approximately 14.8% and 17.7% of the whole concave surface, respectively. This result indicates that the RPM method has high performance in depicting sloping target boundary.
Recent study revealed that menaqunone-4 (MK-4) may be a preferred form among vitamin K (VK) homologues and it would play an important role in the body. There is also consistent evidence that the MK-4 is produced by conversion from dietary VK1 and VK2. VK3 is an intermediate of the conversion reaction. If the serum VK3 concentration can be detected, the relationship between some diseases and VK3 would be clarified. The conventional method to detect VK1 and VK2 is the fluorescence detection method. Therefore, the relationship between VK3 concentration and fluorescence amount has not ever been clarified. Consequently, the purpose of this study was to quantify the relationship between VK3 concentration and fluorescence amount. We constructed the experimental system for the VK3 fluorescence measurement. And we evaluated the relationship between the VK3 concentration and the fluorescence amount.
Superselective intra-arterial infusion for oral cancer has a high anti-cancer effect. Images made by preoperative computed tomography angiography(CTA) and intraoperative digital subtraction angiography(DSA) guide placement of a catheter, which remains in the target artery. However, only these images sometimes cannot help surgeons perform the difficult catheterization. In this report, we present a novel navigation system. This system detected patient's position and orientation by gradient information of maxilla-dental-arch and performed registration by three dimensional CTA image. We made a phantom based on CTA data and we evaluated target registration error(TRE). Measurement device was the optical tracker(NDI Polaris). To evaluate accuracy by the model, the dodecahedron with 1mm hole on each surface was made on the artery bifurcation. At the lingual-facial artery, TRE was satisfied the requirement in one case, this system suggested possibility of adaptation to the superselective intra-arterial infusion.
When oral cancer tissue is irradiated with blue light, red fluorescence is sometimes seen. We think the fluorescence can be a new biomarker for cancer proliferation. Hence, in this study we investigated the properties of the red fluorescence and also examined whether the fluorescence was seen in the proliferative oral tissue other than cancer.
Materials & Methods
Eighteen oral proliferative samples were used in this study. Nine of them were gingival cancer. The most of tissue type was squamous cell carcinoma (11 of the 18 specimens). Fluorescence image of the samples was obtained using an in-vivo imaging system (IVIS, ParkinElmer) with an excitation filter of 420 nm and an emission filter of 620nm.
Results & Discussion
The red fluorescence was seen in 7 of the 18 samples (39%). The fluorescence was not homogeneously distributed in each samples, rather spotty, patchy distribution. When the fluorescent specimens were cut into small pieces, the fluorescence was observed even from the cut surface, suggesting that the fluorescence originates from substances inside cancer tissue. On the other hand, the fluorescence was also seen in granulation tissue (1 of the 3 specimen), thus the fluorescence would not arise from the materials that are unique to cancer cells.
The red fluorescence was seen in approximately 40% of oral proliferative tissue. We intend to identify the origin of the fluorescence and examine whether it can be used for cancer detection.
The scattering effect in light propagation through random media can be suppressed with the phase-conjugate optics. We have applied this technique to the transillumination imaging of animal body using a digital phase-conjugate system. In the experiment, we attempted to restore various incident light patterns through a scattering medium. Fig. 1 shows the images of the incident light patterns (a) and the observed images (b) through the scattering medium. The feasibility of scattering suppression using digital phase-conjugate light was verified as shown in Fig. 1(c).
The low attenuation areas (LAA) in lung are understood one of the important factor for promoting Chronic Obstructive Pulmonary Disease (COPD). Mortality of COPD has been increasing, and World Health Organization (WHO) expects it to become the third leading cause of death in the world by 2030, up from its current tenth place. In this present report, we studied the estimating procedure for confirm the primary changes of LAA using Computer Tomography (CT) images. Under -950 HU CT areas were scored in CT image, and estimated using Goddard's method. No relationships were confirmed in age and smoking history. The data might be indicated that the other factors of promoting LAA have been existed.
Following natural disasters, accidents, and shocking incidents, some children experience mental disorder. A respiration control method that relaxes the body and mind may efficiently prevent and improve mental disorder. Therefore, we developed a stuffed toy using two airbags to measure the respiration wave and lead a child's respiration using the up-and-down movement of the toy's abdomen to help them relax. After evaluating that children's respiration could be measured and guided by the stuffed toy, we then performed an experiment of relaxation effect. Participants in the experiment consisted of 9 healthy girls aged 8-10 years old. We measured the difference of heart rate variation between "Hug condition" (just hugging the stuffed toy) and "Respiration-Leading (RL) condition". The results showed that RL condition made children's heart rate variation lower than Hug condition. This means that the relaxation effect of respiration-leading by the stuffed toy is larger than just hugging it.
Though palpation is an important technique for distinguishing a tumor, the palpation during thoracoscopic surgery is difficult because of the lack of tactile sense. In order to compensate the surgeon's tactile sense, we developed a forceps with two MEMS (Micro Electro Mechanical Systems) triaxial tactile sensors. In this study, we proposed a tumor size estimation method focusing on the detected force difference according to the hardness of the grasping area. Then, we evaluated the size of tumor models located in the soft tissue models to prove the feasibility of the estimation method. The diameter of the 5 mm and 10 mm spherical tumor models located in the tissue models were estimated 4.6 mm and 10.7 mm, respectively. This result indicates the possibility that the proposed method enables to estimate the size of a tumor within an organ.
In this study, a multi-point LDV was developed to improve upon the near infrared laser Doppler flow velocity distribution device for the purpose of non-invasive measurement of in vivo blood flow state. Using the special features of this device, when a follow-up exam was performed on a mouse ear that had undergone a melanoma transplant, it was confirmed that there had been a reduction in the melanoma. It is known that cancer cells can be killed at 40 degrees centigrade, so we believe that the temperature increase at the laser intersection is the cause of the reduction in the melanoma. Therefore, the MLDV that was used in this research is now being considered for use in cancer treatment. The temperature rises of biological tissue when measured at various irradiation depths was announced, and there was a debate regarding the possibility of the use of this device in curative treatment.
[Purpose] The membrane hollow fiber made from dense silicone has an advantage for long-term ECMO application because of no plasma leakage, but is inferior to the micro porous polypropylene membrane in gas permeability. This study proposes a new method to improve gas exchange rate of silicone hollow fiber.
[Material and method] The prototype artificial lung with silicone hollow fiber was designed as an endocapillary blood flow oxygenator. Because the hollow fiber wall was thin and elastic, the pulsatility of blood flow provided expansion and contraction of the fibers. The gas transfer was measured by PO2 and PCO2 in the closed loop circulation mock.
[Results] ΔPO2 increased 50 mmHg when the pulsatile flow in 100 bpm was provided in comparison with non-pulsatile flow. The mean flow rate was 2 L/min and the FiO2 was 1.0. On the other hand, there is no significant difference in ΔPCO2.
Some of oxygenators in extracorporeal membrane oxygenation (ECMO) systems have been demonstrated durability for over 1 week continuous use recently. In this study, we conducted chronic ECMO animal experiment using a membrane oxygenator (BIOCUBE2000), and systematically evaluated the change of thrombus formation due to conditions of anticoagulant therapy and ECMO period by quantifying the thrombus distribution in the oxygenator after ECMO using an image processing. As a result of the area ratios of red thrombus at inlet side, middle of fiber bundle and outlet side were 0.049, 0.001 and 0.013 in the group for 2 weeks without continuous anticoagulation. And, we tried to compare results of the thrombus distributions to numerical analysis for blood flow in the oxygenator. There were similar distributions between observed thrombus in the section images and calculated lower velocity region in the oxygenator.
I have constructed a 4D subacinar model which contains the capillary space in the alveolar wall (Figure). Oxygen transport is computed by the use of computational fluid dynamics in which incompressive Navier-Stokes equation and the diffusion equation are directly coupled. Simulated results indicated that the blood oxygen partial pressure was little influenced by the alveolar wall thickness but highly dependent of the effective blood flow rate. This simulation study will be useful for investigating respiratory pathophysiology and for developing an implantable artificial lung.
Inhaled gas imaging techniques have been used for investigating ventilation distribution. Does the tracer concentration distribution accurately reflect the ventilation distribution? I simulated intra-pulmonary distribution of inhaled gas by the use of computational fluid dynamics with Kitaoka's 4D lung model The simulation results suggested that the concentration distribution of inhaled gas tracer did not quantitatively reflect ventilation distribution. Although the tracer imaging technique is useful for basic investigation of respiratory physiology, clinical evaluation of the ventilation distribution should be directly obtained by image-based motion analysis technique.
Excessive mechanical stretches induce pathological effects including mitochondrial dysfunctions. Among the mitochondrial dysfunctions, alteration of mitochondria morphology has been observed in endothelial cells. Shock waves are used in various medical applications. However, side effects including mitochondria damaging have been reported. Actin cytoskeletons physically link to mitochondria and involve in mechanical stretch induced mitochondrial morphology alterations. Furthermore, shock wave irradiation induced intracellular Ca2+ increase is largely affected by state of actin cytoskeleton polymerization. To understand how shock wave irradiation damage mitochondria, alterations in cytoskeletons were observed in human aortic endothelial cells (HAECs). In this study, actin cytoskeletons were visualized with fluorescence proteins. Alterations in actin cytoskeletons were compared with shock wave irradiation conditions such as peak pressure and irradiation shot numbers.
Shock wave irradiation accelerates angiogenesis and osteogenesis. Thus, it could be possible that shock wave induce physiological responses in cells. At cellular level, shock wave irradiation evokes the intracellular Ca2+ increase. In this evoking, actin cytoskeleton is involved. To verify this involvement of actin cytoskeleton in the evoking of intracellular Ca2+ increase, elasticity of cell substrates was altered to control actin cytoskeleton in bovine aortic endothelial cells. The elasticities used in this study were ~10 kPa through ~1 MPa. Elasticity was altered by altering ratio of base and curing agents of PDMS. When elasticity of cellular substrate was lowed, the intracellular Ca2+ increase represented 2 patterns: one is that Ca2+ increase with the second and subsequent irradiation and another not increase. Thus, it was further suggested that actin cytoskeleton is involved in shock wave irradiation induced intracellular Ca2+ increase.
The purpose is to clarify the efficiency of a micro-periodic structure applied to fluid control mechanism to improve the hydrophobicity. The centrifugal microfluidic platform has a flow channel connecting two same-sized reservoirs. The micro-periodic structure was impressed on the flow channel of the centrifugal fluid valve integrated in the chip. Cortisol sample and ALP-labelled antibody conjugate solution were dropped simultaneously into the injection reservoir. Next, a chemiluminescent substrate was dropped into the reservoir. The substrate was hydrolysed by the ALP and the resultant intensity was measured using an optical reader. The relationship between the intensity, I, and the cortisol concentration, Cort, was given by I = 10×10^5 e^-0.032Cort (count/gate). On the other hand, the relationship without the micro-periodic structure was given by I = 8.5×10^5 e^-0.017Cort (count/gate). The sensitivity of the cortisol immunosensor was improved by adding the micro-periodic structure on the flow channel.
When two flat ring coils are layed on a plane in free space, overlapping about 20%, there can be found a null-coupling point where mutual flux coupling is cancelled to make zero transmission to each other. On such setup we can detect nearby interrupting magnetic material and/or LC-resonant tank circuit which causes extra transmission via cross-coupling to the interrupter. Such detection capabikity would depend on accuracy of null-point setup, driving signal design, gain and bandwidth of detecting amplifier and the size of the interrupter to be detected. Adequate design can detect a similar size tank circuit having Q0=70 or more at several times distance of interlogating coil pair diameter. In this study we aimed to use this for extrra corporeal sensing of intra corporeal passive sensing device. In our model experiment 5cm interlogating coil pair can steadily sense 1cm dia. x 1cm length ferrite cored LC tank circut, at 1 to 2 MHz frequency band.
Mammalian motile sperms make spiral trajectories. We tried to find the factors to make the trajectories. We prepared circular microfluidic channels with diameters of approximately 50 μm and 100 μm made of poly(dimethylsiloxiane), and we compared the trajectory of the motile sperms in the microfluidic channels with and without flow. As a result, percentage of motile sperms with spiral motion increased under fluid flow. The period of spiral motion in the circular channel with diameter of 50 μm was longer than that with diameter of 100 μm.
(Introduction) The various biological phenomena are concern with diffusion. We study about the visualization of glucose diffusion in the cellulose membrane, and make the fittest model to this diffusion phenomenon. (Result) It was possible for the glucose molecule to visualize by ammoniacal silver nitrate solution which was diffused into the cellulose membrane previously. We measured the diffusion distance by the silver density by image analysis. This experimental data seemed to be ogistic behaviour. Then we tried to be fit logistic model by curve fit. In this way, we got the diffusion coefficient D by calculating. This D of glucose molecule in cellulose membrane is approximately D=1.04x10-6[cm2/s]. Then, this value is 6 times as much as that of in the solution. (Conclusion) We visualized the glucose diffusion and measured the diffusion coefficient. This was the support layer of coacervate cellulose membrane had 6 times larger than the diffusion constant in solution.
A physical stimulus is very promising method to promote the regeneration of bone tissue in vitro by stimulating osteoblastic calcification, giving better mechano-compatibility to the regenerated bone. However, the prediction of stimulation effect on the tissue regeneration is still difficult due to the non-linear responses of osteoblasts to the stimulation. In this study, to explain the non-linear relationship between physical stimulus and the osteoblastic response, a mathematical model for an osteoblast was constructed based on the established non-linear models for a nerve cell and a heart muscle cell, which are Hodgkin-Huxley and Luo-Rudy dynamics models, respectively. Since calcium ions (Ca2+) play as second messengers in the mechano-transduction pathway of the osteogenic response, Ca2+ channels were implemented for the constructed model. Our model was validated by observing intracellular Ca2+ dynamics of osteoblasts (MC3T3-E1) after electrical stimulation using intracellular Ca2+ indicator (Fluo-4AM).
Toward a development of noninvasive tissue oxygen consumption monitoring method, we propose an arteriovenous blood oxygen saturation measurement based on near-infrared spectroscopy. For arterial blood oxygen saturation measurement, we employ a conventional arterial blood oxygen saturation measurement method, pulse oximetry. Then, for venous blood oxygen saturation measurement, based on a similar principle of pulse oximetry, we developed a new venous blood photoplethysmographic oximetry using cyclic cuff compression technique (mean pressure: 10mmHg with 10mmHg amplitude, cyclic frequency: 0.1Hz). The noninvasive arteriovenous blood oxygen saturation measurement system comprises two-wavelength, 750/830nm. The calibration curve of blood oxygen saturation measurement was calibrated, without blood-drawing, using theoretical photon propagation model based on radiative transfer. The newly designed noninvasive arteriovenous blood oxygen saturation measurement system was evaluated with healthy subjects' forearms during isometric hand-grip exercise. The noninvasive measurement system could offer reasonable blood oxygen saturation changes during the exercise and following resting period.
In this paper, simultaneous measurement of electromyogram (EMG), Mechanomyogram (MMG), and oxygen dynamics at the forearm is presented by the proposed sensor. The proposed sensor is a layered structure of a transparent thin electrode, a transparent piezo film and near-infrared sensor. EMG, MMG and oxygen dynamics are respectively measured by the electrodes, piezo film and near-infrared sensors. The three types of data are obtained by a pair of proposed sensors. In an experiment, simultaneous measurement of EMG, MMG and oxygen dynamics at the forearm was demonstrated using the proposed sensors. As a result, it was shown that simultaneous measurement of EMG, MMG and oxygen dynamics at the forearm was possible although measurement accuracy was insufficient. In addition, it is suggested that the proposed sensor has the potential for analysis of the muscular activity.
It is important to consider the thigh-calf contact force to analyze the kinetics of a lower limb during deep knee flexion, however, the measured forces have varied very much and difficult to understand systematically. In this study, we considered that the thigh-calf contact force might be estimated by considering not only the individual difference but also the joint angles or the posture of an upper body, and measured the forces and introduced the estimating equation. As a result, the maximum error of estimation was 0.43BW.
Facial paralysis is the loss of voluntary muscle movement on one or both sides of the face inhibits the movement of orbicularis oculus. People with facial paralysis cannot blink which triggers dry eye and it affects the lives of many people. We propose a novel approach for supporting blinking with facial wearable robotic technology. This robot has a novel eyelid gating support mechanism using deformation of elastomer for recreating eye blink, triggered by blink detection on healthy side. We evaluated this system with a healthy participant and indicated the feasibility of eye blink support for people with facial paralysis.
Bio-information are important to confirm body condition.We focus on myoelectricity.It will be expected improvement of exercise efficiency because muscle condition is controlled by sensing and feedback myoelectricity.General myoelectricity measurement method is used some disposable electrodes.These are caused skin irritation and uncomfortable feelings.Furthermore,these are difficult to use for the long time.Therefore,the new system without disposable electrodes are needed.We developed wearable myoelectricity measurement system by using capacitance coupling.The condenser is consisted between skin and electrodes.It can measure myoelectricity in noncontact to the skin.We measured myoelectricity during calf raises by commercial system and developed system.We could measure myoelectricity by developed system.However,myoelectricity by developed system is smaller output than commercial system.This is because of impedance between skin and electrodes became higher.
Developing a ubiquitous hand motion sensing system is valuable for understanding biomechanism and developing Human Computer Interface. Unless to the traditional hand motion sensing technologies which impose the mechanical constriction to user's motion, we have developed an obtrusive hand motion sensing system focusing on the interlocked musculoskeletal structure. The proposed system detects electrically the changes of wrist shape related to the finger motion and estimates finger joint angles by using a multiple regression model. The wristband device with multiple electrodes converts the finger motion to the changes of electrical contact resistance. The parameters of multiple regression model are optimized by using the outputs form the system and a calibrated data glove. The visualization of the estimated finger posture during open-close movement of the hand showed a good result of the estimation. This paper reports the evaluation of the estimated errors of joint angles for several subjects.
Feet with hallux valgus increases deformation from too much weight put on a position of the foot and causes symptoms. Therefore, plain standing X-ray images are used for diagnoses and surgical plan. However, three-dimensional evaluation should offer more accurate pathological information because of three-dimensional deformity of hallux valgus. Therefore, we created a loading device and we have reported that mobility of the first ray in hallux valgus patients are larger than healthy volunteer using weightbearing CTs. We evaluated the mobility of the first TMT joint in 3D and then examined its correlation with degree of deformity using the hallux valgus angle and intermetatarsal angle.