Do Combined Oculomotor and Bimanual Coordination Exercises Instantly Stabilize Balance in Athletes?

Purpose: This study examined the immediate effects of oculomotor and bimanual coordination exercises, as well as a combination of the two, on stability of balance in athletes.

Patients And Methods: Changes in center-of-gravity sway were measured in 30 college student athletes before and after the following three exercise conditions: 1) oculomotor exercises, 2) bimanual coordination exercises, and 3) a combination of oculomotor and bimanual coordination exercises (1+2). The order of these exercises was counterbalanced.

Development of a three-dimensional bioprinter: construction of cell supporting structures using hydrogel and state-of-the-art inkjet technology.

We have developed a new technology for producing three-dimensional (3D) biological structures composed of living cells and hydrogel in vitro, via the direct and accurate printing of cells with an inkjet printing system. Various hydrogel structures were constructed with our custom-made inkjet printer, which we termed 3D bioprinter. In the present study, we used an alginate hydrogel that was obtained through the reaction of a sodium alginate solution with a calcium chloride solution.

Development of mechanical circulatory support devices at the University of Tokyo.

The development of mechanical circulatory support devices at the University of Tokyo has focused on developing a small total artificial heart (TAH) since achieving 532 days of survival of an animal with a paracorporial pneumatically driven TAH. The undulation pump was invented to meet this purpose. The undulation pump total artificial heart (UPTAH) is an implantable TAH that uses an undulation pump.

Development of a novel intrafascicular nerve electrode.

Artificial organs could be controlled using autonomic neural signals, because they exhibit rapid responses to physical needs similar to those of natural organs. A nerve electrode must satisfy many requirements to measure autonomous neural signals such as a long lifetime, high signal-to-noise ratio, multichannel recording, simple installation into a nerve fascicle, and good manufacturing productivity. The purpose of our study is to propose and evaluate a novel nerve electrode that satisfies these conditions, which to date has not been developed.

Microcirculation of the bulbar conjunctiva in the goat implanted with a total artificial heart: effects of pulsatile and nonpulsatile flow.

A new system to observe the microcirculation on the bulbar conjunctiva was developed using a digital high definition microscope to investigate the influence of the flow patterns on the microcirculation in a goat with a total artificial heart (TAH). The undulation pump TAH was implanted into the goat. When the whole body condition became stable, the flow pattern was modulated between the pulsatile and the nonpulsatile mode, and the changes in the microcirculation were observed.

A temporal and spatial analysis of cavitation on mechanical heart valves by observing faint light emission.

Cavitation on mechanical heart valves (MHVs) could cause the mechanical failure of the occluder. A simple and reliable in vitro test method to evaluate cavitation potential must be developed. The bubble implosion damages the MHV material; thus, observing the behavior of the bubble implosion is essential.

Evaluation of pulsatile and nonpulsatile flow in microvessels of the bulbar conjunctiva in the goat with an undulation pump artificial heart.

This study has three purposes, as follows. The first is to develop a microscopic system to observe the microcirculation of animals implanted with an artificial heart. The second is to investigate the influence of flow pattern change from pulsatile to nonpulsatile on the microcirculation.

Preliminary study of a new type of energy transmission system for artificial hearts.

A transcutaneous energy transmission (TET) system is the most common way to power artificial hearts and ventricular assist devices. However, an external battery used with a TET system poses several problems, such as its heavy mass, small charge capacity, and long recharging time. The battery is indispensable when patients want to be ambulatory.

Functions for detecting malposition of transcutaneous energy transmission coils.

A transcutaneous energy transmission system (TETS) for artificial hearts and ventricular assist devices uses electrical coupling of power between external and implanted coils. If the position of coils changes relative to each other, the TETS cannot feed the required power of the implanted device. During activity or sleep, the coils may move accidentally.

Pathophysiologic study of goats with undulation pump total artificial heart: those that survived for more than 1 month.

The undulation pump total artificial heart is an implantable total artificial heart that is being developed at the University of Tokyo. Many advances in our system have been made by the adoption of hardware and software solutions that enabled the animals with the undulation pump total artificial hearts to survive more than 1 month. Pathophysiologic observations were performed for these goats that survived.

A new approach to detection of the cavitation on mechanical heart valves.

The cavitation on the mechanical heart valves (MHVs) is thought to be a cause of the mechanical failure of the occluder; also, the free radicals that would be generated when the cavitation bubbles implode might affect the patients chemically. These cavitation effects are attributed to the bubble collapse. Therefore, it is important to detect the bubble implosion behavior to analyze the cavitation on MHVs.

Miniature vibrating flow blood pump using a cross-slider mechanism for external shunt catheter.

The prototype of the miniature vibrating flow pump (VFP) is developed for the external shunt catheter. The cross-slider mechanism is applied to vibrate the tube, which causes the pumping effect. This mechanism results in successful development of the miniature and lightweight VFP.

A study on an energy supply method for a transcutaneous energy transmission system.

This study proposes a new type of a transcutaneous energy transmission system (TETS) that can supply electrical power for an implanted device without an external battery. In this system, the power is supplied from the floor to the shoes of the patients through coils that are set beneath the floor and the bottom of the shoes. If the patients wear the special shoes, they will be able to move freely on the specially designed floor without an external battery.

Progress in the control system of the undulation pump total artificial heart.

The undulation pump total artificial heart (UPTAH) is a small implantable total artificial heart. As the UPTAH generates outflow and inflow at the same time, control of the UPTAH is very difficult. Therefore suitable control methods specifically for the UPTAH should be established.

[A case of subacute bacterial endocarditis showing acute macular neuroretinopathy-like lesions].

Purpose: We report one case of mimic fundus lesions with acute macular neuroretinopathy due to subacute bacterial endocarditis.

Case: A 55-year-old male had about a 1 DD reddish petal-shaped lesion at the level of the retinal pigment epithelium in the macula and a white lesion about 1/6 DD at the level of the retinal pigment epithelium in the upper fovea. Fluorescein angiography showed the reddish lesion to be hypofluorescence due to a filling defect and indocyanine green angiography showed the hypofluorescence was due to a circulatory disturbance of the choriocapillaris.

Development of design methods of a centrifugal blood pump with in vitro tests, flow visualization, and computational fluid dynamics: results in hemolysis tests.

There are few established engineering guidelines aimed at reducing hemolysis for the design of centrifugal blood pumps. In this study, a fluid dynamic approach was applied to investigate hemolysis in centrifugal pumps. Three different strategies were integrated to examine the relationship between hemolysis and flow patterns.

Computational fluid dynamic analyses to establish design process of centrifugal blood pumps.

To establish quantitative, efficient design theories for centrifugal blood pumps, computational fluid dynamics (CFD) analyses were compared to the results of flow visualization tests and hemolysis tests, mainly on the Nikkiso centrifugal blood pump. The results turned out to coincide in the velocity vector plots. CFD analysis revealed that the smaller the gap is, the greater the shear stress becomes.

Flow visualization as a complementary tool to hemolysis testing in the development of centrifugal blood pumps.

With a 250% scaled-up pump model, high speed video camera, and argon ion laser light sheet, flow patterns related to hemolysis were visualized and analyzed with 4 frame particle tracking software. Different flow patterns and shear distributions were clarified by flow visualization for pumps modified to have different hemolysis levels. A combination of in vitro hemolysis tests, flow visualization, and CFD analysis suggested a close relationship between hemolysis and high shear caused by small impeller/casing gaps.

Early changes in circulating blood volume and volume regulating humoral factors after implantation of an electrohydraulic total artificial heart.

The early changes in circulating blood volume (CBV) and volume regulating humoral factors after implantation of an electrohydraulic total artificial heart (EH-TAH) were investigated in a calf and compared with results in a sham operated control calf. CBV was measured by the dye dilution method using indocyanine green. CBV and humoral factors were periodically investigated.

In vitro and in vivo evaluation of a left-right balancing capacity of an interatrial shunt in an electrohydraulic total artificial heart system.

The authors evaluated the basic performance of an interatrial shunt (IAS) made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in compliance with the amount of bronchial flow and the size of the IAS. The IAS of 4.

In vitro and in vivo heat dissipation of an electrohydraulic totally implantable artificial heart.

The authors evaluated the heat transfer characteristics of an electrohydraulic totally implantable artificial heart (EH-TAH) developed at our institute. In three in vitro experiments, the heat dissipation of the EH-TAH was investigated. First, the EH-TAH was connected to a closed mock circuit filled with 1 L of saline, and driven at an input power of 20 W.