Development of a noninvasive olfactory stimulation fMRI system in marmosets.

Olfactory dysfunction is associated with aging and the earliest stages of neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases; it is thought to be an early biomarker of cognitive decline. In marmosets, a small non-human primate model used in brain research, olfactory pathway activity during olfactory stimulation has not been well studied because of the difficulty in clearly switching olfactory stimuli inside a narrow MRI. Here, we developed an olfactory-stimulated fMRI system using a small-aperture MRI machine.

Prediction and prevention system for Severe Acute Respiratory Syndrome CoronaVirus 2 infection by preempting the onset of a cough.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is fast becoming one of the most significant infections worldwide. Of all the causes of SARS-CoV-2 infection, airborne-droplet infection via coughing is the most common. Therefore, if predicting the onset of a cough and preventing infection were possible, it would have a globally positive impact.

In Vitro Modelling for Bulging Sinus Effects of an Expanded Polytetrafluoroethylene Valved Conduit Based on High-Speed 3D Leaflet Evaluation.

The study aimed to develop a pulmonary circulatory system capable of high-speed 3D reconstruction of valve leaflets to elucidate the local hemodynamic characteristics in the valved conduits with bulging sinuses. Then a simultaneous measurement system for leaflet structure and pressure and flow characteristics was designed to obtain valve leaflet dynamic behaviour with different conduit structures. An image preprocessing method was established to obtain the three leaflets behaviour simultaneously for one sequence with two leaflets images from each pair of three high-speed cameras.

Development and initial performance of a miniature axial flow blood pump using magnetic fluid shaft seal.

In this study, we developed a new catheter-mounted micro-axial flow blood pump (MFBP) using a new miniature magnetic fluid shaft seal (MFSS). The prototype of the catheter-mounted MFBP had a maximum diameter of 8 mm and a length of 50 mm. The new MFSS composed a neodymium magnet ring, an iron ring, and a magnetic fluid particularly designed for the MFSS.

Acute Phase Pilot Evaluation of Small Diameter Long iBTA Induced Vascular Graft "Biotube" in a Goat Model.

Objective: There is a need for small diameter vascular substitutes in the absence of available autologous material. A small diameter, long tissue engineered vascular graft was developed using a completely autologous approach called "in body tissue architecture technology (iBTA)". The aim of this pilot study was to evaluate "Biotubes", iBTA induced autologous collagenous tubes, for their potential use as small diameter vascular bypass conduits.

Development of muscle connection components for implantable power generation system.

We have been developing an implantable power generation system that uses muscle contraction following electrical stimulation as a permanent power source for small implantable medical devices. However, if the muscle tissue is overloaded for power generation, the tissue may rupture or blood flow may be impaired. In this study, we developed a new muscle-connecting component that solves these problems.

Design of an Artificial Tongue Driven by Shape Memory Alloy Fibers.

Dysphasia is one of the complications which may cause functional disability after the surgical treatment of oral cancer. The loss of the function derived by tongue and other oral tissues impairs the retention and delivery of liquids and food masses as well as the swallowing motion into pharynx. As accumulation of liquids or food masses in the larynx can lead to pneumonia, therefore swallowing support to improve each coordination of the tongue, the epiglottis and the esophagus in the process of swallowing is highly desirable.

Impact of nocturnal hypoxemia on the recurrence of atrial tachyarrhythmia after catheter ablation of atrial fibrillation.

Factors causing atrial tachyarrhythmia recurrence after catheter ablation (CA) of atrial fibrillation (AF) remain undetermined. This study aimed to investigate the effect of nocturnal hypoxemia on the recurrence of atrial tachyarrhythmia after CA of AF. Among 594 patients with AF who underwent an ambulatory sleep study at the National Cerebral and Cardiovascular Center, Suita, Osaka, Japan (2014-2019), 365 underwent CA of AF; 290 patients who underwent CA were followed up for > 3 months.

Reflected wave intensity increases based on aortic diameter after endovascular aortic therapy in a goat model.

Reflected wave increases after endovascular aortic repair (EVAR) in patients with aortic aneurysm. This affects the left ventricular (LV) diastolic function and leads to a poor prognosis. This study aimed to evaluate the relationship between increased reflected wave amplitude and aortic diameter after EVAR.

Relationship between electrical gaps after Maze procedure and atrial tachyarrhythmias and ablation outcomes after cardiac surgery and concomitant Maze procedure.

Atrial tachycardia (AT) and atrial fibrillation (AF) commonly occur after cardiac surgeries (CSs). This study investigated the mechanisms and long-term outcomes of AT and AF ablation after various Maze procedures, particularly whether atrial tachyarrhythmias after the Maze procedure occur due to gaps in the Maze lines. We analyzed 37 consecutive cases with atrial tachyarrhythmias after the Maze procedures and concomitant CSs between 2007 and 2019.

Hemolysis and von Willebrand factor degradation in mechanical shuttle shear flow tester.

Chronic blood trauma caused by the shear stresses generated by mechanical circulatory support (MCS) systems is one of the major concerns to be considered during the development of ventricular assist devices. Large multimers with high-molecular-weight von Willebrand factor (VWF) are extended by the fluid forces in a shear flow and are cleaved by ADAMTS13. Since the mechanical revolving motions in artificial MCSs induce cleavage in large VWF multimers, nonsurgical bleeding associated with the MCS is likely to occur after mechanical hemodynamic support.

Diagnosis System for Swallowing and Peristalsis Function for Artificial Tongue and Esophagus Development.

With the progress of surgical technology, the survival rate after resection of esophageal and tongue carcinomas has improved. However, the surgical protocol for esophageal and tongue surgery is complex, and surgery for elderly esophageal and tongue carcinoma patients with cardiopulmonary dysfunction is difficult. Using an artificial tongue and esophagus will be helpful for patients.

Evaluation of the Pulse wave in the face for the patients with rotary blood pump (RP) in the Outpatient clinic.

Rotary blood pump (RP) is one of the most important devices in the treatment of profound heart failure and is known to reduce the pulse in the blood pressure waveform, especially when it is used for axial flow. In an outpatient clinic, checking the pulse of a patient implanted with an RP can help diagnose the patient's condition. For that purpose, animal experiments with healthy adult goats implanted with the EVAHEART system were carried out after obtaining ethical committee approval.

Modeling Approach for An Aortic Dissection with Endovascular Stenting.

Repair of dissected aorta requires remodeling the structure of the media. Modeling approaches specific to endovascular stenting for aortic dissection have been reported. We created a goat model of descending thoracic aortic dissection and reproduced its morphological characteristics in a mock circulatory system.

Development and accuracy evaluation of a degree of occlusion visualization system for roller pumps used in cardiopulmonary bypass.

In roller pumps used for cardiopulmonary bypass (CPB), the degree of blockage within the tube resulting from compression of the tube by the rollers, or the degree of occlusion, is closely related to hemolysis, with both tight occlusive and non-occlusive degrees promoting hemolysis. There are as yet no international standards regarding methods of adjusting occlusiveness, and the amount of mechanical stress exerted upon blood remains unknown. To prevent hemolysis during CPB using roller pumps, there is a need to clarify and quantitatively assess the mechanical stress of the occlusiveness of the roller pump.

Pulse rate variability: a new biomarker, not a surrogate for heart rate variability.

With the popularization of pulse wave signals by the spread of wearable watch devices incorporating photoplethysmography (PPG) sensors, many studies are reporting the accuracy of pulse rate variability (PRV) as a surrogate of heart rate variability (HRV). However, the authors are concerned about their research paradigm based on the assumption that PRV is a biomarker that reflects the same biological properties as HRV. Because PPG pulse wave and ECG R wave both reflect the periodic beating of the heart, pulse rate and heart rate should be equal, but it does not guarantee that the respective variabilities are also the same.

In vitro performance of trans-valve left ventricular assist device installed at aortic valve position.

In this study, we developed a trans-valve left ventricular assist device (LVAD) that unites a rear-impeller axial-flow blood pump (AFBP) and a polymer membrane valve placed at the aortic valve position. The diameter and length of the rear impeller AFBP was 12 and 63 mm, respectively. The polymer membrane valve was similar to the jelly-fish valve consisting of a valve leaflet made of silicone rubber (thickness 0.

Cloud Database Construction for the Expressway Design by the use of the Medical Information.

Your heart rate and blood pressure are respond to the curve, slope, lane width, and road surface friction coefficient of the expressway design. However, no report was reported concerning about the Expressway design from the viewpoint of medical information of the driver until now. To prevent the traffic accident, human factor is of course one of the most important factors.

Development of rear-impeller axial flow blood pump for realization of axial flow blood pump installed at aortic valve position.

In this study, rear-impeller axial flow blood pumps (RIAFBP) were developed to realize a trans-valve axial ventricular assist device (VAD) which consists of the latter blood pump and a polymer monomembrane aortic valve, such as the jellyfish valve. The motor of the RIAFBP is installed in the left ventricle, and its impeller is placed at the aortic valve position. In the prototype RIAFBP, the rotation of the motor is sustained by polyethylene bushings.

Nonthrombogenic, stretchable, active multielectrode array for electroanatomical mapping.

High-precision monitoring of electrophysiological signals with high spatial and temporal resolutions is one of the most important subjects for elucidating physiology functions. Recently, ultraflexible multielectrode arrays (MEAs) have been fabricated to establish conformal contacts with the surface of organs and to measure propagation of electrophysiological signals with high spatial-temporal resolution; however, plastic substrates have high Young's modulus, causing difficulties in creating appropriate stretchability and blood compatibility for applying them on the dynamically moving and surgical bleeding surface of the heart. Here, we have successfully fabricated an active MEA that simultaneously achieves nonthrombogenicity, stretchability, and stability, which allows long-term electrocardiographic (ECG) monitoring of the dynamically moving hearts of rats even with capillary bleeding.

Idiopathic ventricular arrhythmias arising from the posterior septum of tricuspid and mitral annuli: comparison of electrocardiographic characteristics and outcomes of catheter ablation.

Purpose: Ventricular arrhythmia (VA) arising from the tricuspid annulus in the posterior septum (PS) (TAPS-VA) has similar electrocardiographic characteristics as VA arising from the mitral annulus in the PS (MAPS-VA) because the two locations are adjacent. We examined the electrocardiographic characteristics that differentiate MAPS-VA from TAPS-VA and the efficacy of catheter ablation.

Methods: We studied 13 patients whose VAs were successfully ablated in the TAPS (n = 7) and MAPS (n = 6).

Measurement of hemodynamic changes with the axial flow blood pump installed in descending aorta.

We have developed various axial flow blood pumps to realize the concept of the Valvo pump, and we have studied hemodynamic changes under cardiac assistance using an axial flow blood pump in series with the natural heart. In this study, we measured hemodynamic changes of not only systemic circulation but also cerebral circulation and coronary circulation under cardiac support using our latest axial flow blood pump placed in the descending aorta in an acute animal experiment. The axial flow blood pump was installed at the thoracic descending aorta through a left thoracotomy of a goat (43.