We have developed a novel electronic musical instrument with a pre-programmed score, called “Cymis,” to help the disabled enjoy playing musical pieces. In 2008, field experiments commenced at a nursing home (capacity 52 clients; average age 58.6; cerebral palsy 32 clients). The purpose of the present study was to demonstrate that Cymis is useful and effective for helping the severely disabled maintain or improve their quality of life. First, the accessibility of Cymis was revealed by the fact that 34 clients (63%) played Cymis for an average of 5.6 years. Second, each client’s progress in performance, which possibly reflects improvements of upper-limb motor control function, was examined for the longest duration of over 7 years. Among 31 clients, 13 (42%) showed progress, 17 (55%) showed no change (5 of whom showed progress initially but then regressed to their original status), and 1 (3%) revealed deterioration in condition. Third, psychological effects were measured using an original Face Scale before and after playing Cymis, for a total of 395 performances by 38 clients. Clients became happier in 208 performances (53%), showed no changes in 139 (35%), and became sadder in 48 (12%). Finally, with respect to their care plans, 19 of 52 clients (37%) selected Cymis in 2015, and this number itself implies the importance of Cymis. Basic reasons for selection were investigated by care workers’ assessments from mental and psychological perspectives. In conclusion, Cymis was useful, effective, and attractive to the disabled; it permitted them to enjoy playing music that might not otherwise be possible, and some evidence of therapeutic effect was found.

Bipedal locomotion requires an automatic process for rhythmic motor generation, as well as volitional and precise motor control for purposeful action. The neural substrates for these two distinct locomotion controls in humans are still unclear. This functional magnetic resonance imaging (MRI) study investigated the neural activity of the locomotor-related brain regions along with participants' lower limb behavior. Participants lay face-up in the MRI bore and moved their legs up and down at the knees under two conditions. Under the non-obstacle condition, they moved their legs while watching a point-of-view video that showed walking straight along a corridor at a constant speed. On the other hand, under the obstacle condition, the point-of-view video showed walking while avoiding obstacles in the passage. Two white markers were pasted on the soles of the participants' feet and images were captured by a video camera throughout the experiment to track the participants' lower limb movements. The horizontal fluctuation of lower limb movement was extracted offline. We assumed that the horizontal fluctuation reflected participants' volitional behavior of lower limb movement. The results showed that the obstacle condition elicited greater fluctuation of lower limb movement compared to the non-obstacle condition, and elicited brain activation in wider areas including the parietal and occipital lobes compared to the non-obstacle condition. The involvement of the parietal and occipital lobes in volitional control is consistent with findings of previous animal studies. In a correlation analysis between the signal change extracted from the locomotor-related cortical/subcortical regions and the horizontal fluctuation of the feet, activities in the cortical motor areas (primary motor cortex, premotor cortex, and supplementary motor area) showed weak but significant correlation with the fluctuation of lower limb movement. Activities in the cerebellar and mesencephalic locomotor regions showed no significant correlation, but almost constant activation irrespective of fluctuation of the lower limbs. These results suggest that the parietal, occipital cortices, and cortical motor areas are involved in volitional control.

Surgery can become safer and more reliable if the conditions of the organs can be physically and quantitatively assessed through simultaneous intraoperative measurements and physical estimations of deformed organs. This study proposes a new method for estimating external forces based on local displacement of elastic bodies. Using this method, one can estimate the magnitude and position of forces not only on the forceps but also in the invisible field. Simulation studies confirmed the effectiveness of this method. The experimental results showed that partial observation of a deformed shape achieved successful estimation of the external forces.

In this study, we improved upon a high-input impedance monitoring device comprising capacitive sheet electrodes placed under a bed sheet, aiming to detect all ECG waves including T waves. To accomplish this, we widened the passbands for ECG and respiratory movement (RM) signals. However, because this widening may lower noise tolerance, we substituted conventional front-end buffers with buffers able to discharge DC potential. Further, the backside of the modified electrode was doubly shielded by using the electric potential of the buffer's output and ground. We also introduced a virtual midpoint circuit to realize stable ECG and independent RM measurements of the chest and abdomen with the goal to detect obstructive sleep apnea in future applications. We tested our device on seven healthy adults during a six-hour sleep experiment. In all subjects, we detected T waves and observed ECG and RM signals in supine and lateral positions. In experiments in which respiratory rate was changed at regular intervals, the RM signal was synchronized with the simultaneously measured reference signal. The sensitivity and accuracy of R waves averaged over all subjects were 93.2% and 92.9%, respectively. Both averaged sensitivity and accuracy for T waves were 94.5%, while averaged accuracy of chest and abdominal RM was 70.9% and 74.0%, respectively. The results for ECG signals indicate that our improved system is applicable to unconstrained monitoring of vital signs in adults. Although there is still room for improvement in RM measurements, the results suggest that our system may also be used to detect variations in breathing.

The dialysis fluid flow and solute removal performance of newly developed dialyzers and a downsized dialyzer were evaluated using a dimensionless correlation equation related to the mass transfer coefficient of the dialysate-side film in a mass transfer model, which was used in quantitative analyses in our previous study. The solute removal performance is greatly dependent on the dialysis fluid flow for low molecular weight solutes. Hence, the recently developed dialyzers are based on new design concepts incorporating jackets or hollow fibers that provide an evenly distributed flow. The new dialyzers tested were APS-15SA, PES-15Sαeco, PN-140S, and NV-15U. APS-15DSplus was used as a downsized version of the APS-15SA. The dialysate-side equivalent diameter de is smaller in the APS-15DSplus than in the APS-15SA, while the other design specifications are identical for these two devices. We measured vitamin B12 clearance with the dialyzers operated at a blood-side flow rate QB = 200 mL/min, dialysate-side flow rates QD = 300–700 mL/min, and a net filtration rate QF = 0 mL/min. We then calculated the overall mass transfer coefficient. Using this value, we derived the dimensionless correlation of the Sherwood number (Sh), which includes the dialysate-side film mass transfer coefficient (kD) and Reynolds number (ReD). The exponent of ReD was approximately 0.5 for all the dialyzers. The newly developed dialyzers have various design features for improving dialysis fluid flow. Unlike previous devices, the various new designs result in a convergence of performance. A comparison of APS-15SA and the downsized APS-15DSplus showed similar dependence of kD on ReD. This finding is novel and is attributed to the similarity in the relationship between dialysate-side fluid flow and dialysate-side film mass transfer in the two devices. In both dialyzers, the jacket has a full baffle and short taper structure, and the wave design of the hollow fiber membranes is identical. However, de was smaller in APS-15DSplus. Thus, analogous design concept employing the dimensionless correlation can be adopted for downsizing a device.

Spatial control of cell position is essential for numerous studies in tissue engineering, such as generation of linearly patterned muscle tissues, radially patterned liver lobule tissues, and circularly formed anal sphincter. This study proposes a novel method capable of patterning cells in a certain shape on a cell cultivation substrate. The concept is to pattern cells along the nodal position of resonance vibration on a cell cultivation substrate. Note that there are numerous resonance vibrations with different nodal patterns. In this study, we constructed a cell cultivation device consisting of a metallic cell cultivation substrate that can be excited to generate resonance vibration using a piezoelectric ceramic disk glued to the back of the substrate. In this study, we generated resonance vibration with a cross-circle nodal pattern. The cultivation substrate was a ø40 mm × 1 mm stainless steel plate, and the resonance frequency of the vibration was 21.4 kHz. Using the device, we conducted cell patterning experiments employing calf chondrocytes using various vibration amplitudes (1.0, 1.5, and 2.0 µmp-p). Cells were cultured for 2 hours. After the experiment, the cell density distribution on the substrate was measured by staining viable cells with calcein. Additionally, we confirmed the viability of the patterned cells after exposure to acoustic pressure produced by the resonance vibration by counting the number of cells attached to the substrate. Viable cells were successfully patterned along the nodal position when the vibration amplitude was 1.5 µmp-p. The number of cells attached to the substrate was 99.2% of that without vibration. Conversely, when the amplitude was 1.0 µmp-p, the cells were not patterned. The acoustic pressure produced by 1.0-µmp-p vibration was not large enough to move cells. Similarly, the cells could not be patterned when the amplitude was 2.0 µmp-p. In this case, flow of the culture medium induced by the high acoustic pressure probably prevented the cells from patterning. In conclusion, cells can be patterned along the nodal position of resonance vibration generated with an appropriate vibration amplitude. We believe that this method has great potential for use in tissue engineering.

Good mass transfer and high cell density culture are required for bioreactors using animal cells. These criteria can be met by fabricating a tissue in the bioreactor. In the present study, polypod particles were prepared using agarose, carrageenan, calcium alginate, and hydroxyapatite. The particles were then packed into reactors, and the reactors were filled with enzymatically cross-linked gelatin. Reactors with flow channels were then obtained upon dissolution of the gel particles. Cell adhesion, growth, and expression of organ (liver) function in the reactor were subsequently examined. Experiment using CHO-K1 cells suggested that the cells adhered and grew on the internal surface of the flow channels. HepG2 cells inoculated into the reactor expressed liver-specific functions over the 3-day culture period examined. Thus, the current findings demonstrate that the method developed can be applied to fabricate bioreactors to provide physiologically active substances and medical treatments for tissue engineering. Furthermore, this method was extended to the preparation of a hydroxyapatite-packed reactor by combining calcium alginate gel particles and hydroxyapatite. Therefore, this technique is expected to be applicable to both soft tissue models and hard tissue models such as bone.

We investigated the effects of two prominent aromas, lavender and jasmine, on peripheral and cardiac autonomic nervous system activity under stressful conditions, in a highly reproducible manner using an olfactometer. The subjects comprised 17 healthy men aged 20–24 years. In this within-subjects study design, all subjects were required to perform a simple calculation task for 30 min to induce cognitive stress, and aroma from lavender or jasmine essential oil or a control stimulus was inhaled intermittently (first 20 s of each 1-min interval) to prevent olfactory fatigue. The control stimulus was provided by triethyl citrate, an odourless solvent. In addition to subjective psychological assessments using a visual analogue scale, the temperature at the tip of the nose and cardiac activity on electrocardiogram were recorded as indices of peripheral and cardiac autonomic nervous system activities, respectively. Significant decreases in nose tip temperature and high-frequency (HF) component of heart rate variability (HRV), and a significant increase in heart rate were observed under all three conditions. However, compared with the control condition, lavender inhalation induced significantly greater decreases in nose tip temperature (p < 0.01) and HF component of HRV (p < 0.01), which indicated greater enhancement of sympathetic nervous system activity and suppression of parasympathetic nervous system activity. On the other hand, lavender inhalation induced a positive mood, less subjective stress, and increased concentration during the task (p < 0.01). These contradictory results of enhanced physiological stress response and lower subjective stress induced by lavender inhalation under stressful conditions suggest that lavender aroma may have effects other than sedation. Further studies are necessary to further clarify these effects.

Right ventricular outflow tract (RVOT) reconstruction surgery is one of the surgical strategies for congenital heart failure, and is commonly used for the treatment of severe heart failure with pulmonary valvular problems. An expanded polytetrafluoroethylene (ePTFE) pulmonary valve was invented for RVOT reconstruction, and the authors have tested its hemodynamic and hydrodynamic characteristics for design improvement. The special features of the ePTFE valve are as follows: (a) anatomically identical trileaflet structure, and (b) bulging sinuses in the vicinity of leaflets. In this study, we used three types of pulmonary valves; an ePTFE valve with bulging sinuses, an ePTFE valve in straight conduit, and a natural pulmonary arterial valve extracted from a goat after the animal experiment. Then we measured the hemodynamic characteristics of the various types of ePTFE valves using a mechanical pulmonary circulatory system. Next, using the pressure and flow data derived from the mechanical circulatory system, we calculated the mechanical design parameters of the ePTFE valves based on a numerical modeling method by inverse analyses. The mathematical parameters we used in the model were inertia, damping, and stiffness coefficients, and we compared these values among three types of pulmonary valves. We succeeded to estimate the mechanical parameters for each valve from the hemodynamic data. The results suggest that the ePTFE valve with bulging sinuses may exhibit similar parametric characteristics to those calculated from the natural pulmonary heart valves.

Recently, ultra-low field MRI (ULF-MRI) has attracted attention as a medical imaging technique. In ULF-MRI, because nuclear magnetization is very weak, hyperpolarized nuclear magnetization is expected to increase the intensity of MR signals. The use of hyperpolarized xenon gas, which has substantially larger polarization ratio than protons, has been proposed. However, MR signals decay rapidly when a large gradient field is used in MR signal detection. Meanwhile, the sweep imaging with Fourier transformation (SWIFT) approach, which utilizes an adiabatic radio frequency pulse with amplitude and frequency modulations and small gradient field, has been proposed. In this study, we evaluated the influence of the parameters used in the SWIFT approach on hyperpolarized xenon imaging in ULF-MRI. To simulate signal reconstruction of hyperpolarized xenon with the SWIFT approach, we calculated motions of magnetization according to the Bloch equation using a fourth-order Runge–Kutta method. Two pyramidal profiles with widths of 25 and 75 mm were simulated as nuclear magnetization density profiles. The motions of magnetization and the acquired MR signals caused by magnetization were subsequently computed using various parameters comprising sampling points, bandwidth, and duration of excitation. The signals were finally reconstructed using a cross-correlation method. The results indicated that reconstructed signals could be calculated from the MR signals acquired by the SWIFT approach at a bandwidth of 1, 10 or 100 kHz and a matrix size of 100, 200 or 400. However, signals reconstructed using a bandwidth of 1 kHz or a matrix size of 100 were distorted near the position where the signal changed. These results suggest that a wide bandwidth (≥10 kHz) and a large matrix size (≥200) should be used for better signal reconstruction from the MR signals acquired by the SWIFT approach, and that the Larmor frequency of ULF-MRI should be greater than 10 kHz to achieve wide bandwidth. In addition, DC component distortions in the reconstructed signals increased when distribution of nuclear magnetization density in the field-of-view (FOV) was large. Therefore, a wide FOV should be selected to reduce DC component distortions.