Viability variation of T-cells under ultrasound exposure according to adhesion condition with bubbles.

Purpose: Although cellular immunotherapy is expected as a new cancer treatment, its therapeutic efficiency is limited in solid tumors, because most cells return to the bloodstream rather than adhere to the target site. Therefore, we are motivated to develop a technique to concentrate the cells in the blood flow using active control of bubble-surrounded cells under ultrasound exposure considering both aspects of cell controllability and viability.

Methods: We prepared a lipid bubble conjugating ligand to adhere to the surface of the T-cells.

Registration between 2D and 3D Ultrasound Images to Track Liver Blood Vessel Movement.

Background: For the accurate positioning of surgical tools, conventional intraoperative navigation systems have been developed to recognize the relationship between target positions and the tools. However, since an internal organ is deformed during the operation, registration between realtime two-dimensional (2D) ultrasound images and three-dimensional (3D) CT or MRI images is not always effective. Therefore, this study developed image registration between 2D and 3D ultrasound images considering deformation for tracking target vessel movement in the liver.

Ultrasound image-guided gene delivery using three-dimensional diagnostic ultrasound and lipid-based microbubbles.

Gene therapy is a promising technology for genetic and intractable diseases. Drug delivery carriers or systems for genes and nucleic acids have been studied to improve transfection efficiency and achieve sufficient therapeutic effects. Ultrasound (US) and microbubbles have also been combined for use in gene delivery.

Three-dimensional extension of blood vessel network by combining multiple ultrasound volumes from different directions.

We have previously proposed the use of acoustic radiation force in blood vessels for therapeutic application of ultrasound. For this purpose, we have developed a blood vessel network reconstruction algorithm to fuse between B-mode and Doppler-mode volumes. However, a size of ultrasound volume was insufficient to recognize the network for treatment.

Effect of ultrasonic irradiation on bacterial biofilms.

Purpose: The purpose of this study was to clarify the effect of ultrasonic irradiation on biofilm produced by Staphylococcus epidermidis (S. epidermidis), which causes central venous catheter-related infections.

Materials And Methods: Staphylococcus epidermidis (S.

Active induction of in vivo microbubbles by acoustic radiation force at the bifurcation of blood vessel and its evaluation.

Alhough the development of drug delivery system using microbubbles and ultrasound is expected, because microbubbles diffuse in bloodstream, we have so far reported our attempts for active control of the microbubbles in flow by acoustic radiation force in order to increase local concentration of the microbubbles. However, there was no evidence that in vivo microbubbles act as similar as in vitro experiments, because there were limitations for reproduction of in vivo conditions. In this study, we have elucidated the relationship between brightness variation and microbubbles concentration in the suspension to estimate the absolute concentration in an invisible condition considering in vivo experiment.

Control of a thin catheter bending at bifurcation points in artificial blood vessel by using acoustic radiation force.

In this paper, control of a thin catheter bending by using acoustic radiation force was carried out to develop precise and noninvasive surgery in small blood vessel. First, it was elucidated that the acting force to a thin catheter made from perfluoroalkoxy (PFA) copolymer could be obtained from the cantilever equation in the effective range, where the displacement of the catheter divided by the cube of the length of the catheter was less than 1.0×10(-5) mm(-2).

Production of acoustic field with multiple focal points to control high amount of microbubbles in flow using a 2D array transducer.

We have newly developed a 2D array transducer to control the behavior of microbubbles, which is different from that for HIFU therapy, to emit continuous wave by designing acoustic field including multiple focal points. In the experiment using a straight path model, we have confirmed that higher concentration of acoustic energy does not result more aggregation. We also have confirmed the trapped areas of microbubbles are located not in the peak of the distribution of sound pressure, but in the middle range.

Active control of microbubbles stream in multi-bifurcated flow by using 2D phased array ultrasound transducer.

We have previously reported our attempt to propel microbbles in flow by a primary Bjerknes force, which is a physical phenomenon where an acoustic wave pushes an obstacle along its direction of propagation. However, when ultrasound was emitted from surface of the body, controlling bubbles in against flow was needed. It is unpractical to use multiple transducers to produce the same number of focal points because single element transducer cannot produce more than two focal points.

Image plane positioning by pneumatic actuators for ultrasound guidance.

Image guided procedures such as percutaneous needle insertion or high intensity focused ultrasound, have become quite widespread. In images acquisition, ultrasound (US) is convenient to use in a conventional operating room, and inexpensive compared to CT and MRI. However, US requires to handle an US probe and do not have the base coordinate system.

Supporting reconstruction of the blood vessel network using graph theory: an abstraction method.

The blood vessel network (BVN) has a complex structure. As this structure is unique for each individual, it is not possible to establish a general model for the BVN. However, many medical applications do rely on this structure.

Observation of flow variation in capillaries of artificial blood vessel by producing microbubble aggregations.

Microbubbles form their aggregations between the neighboring microbubbles by the effect of secondary Bjerknes force under ultrasound exposure. However, because of the difficulty to reproduce a capillary-mimicking artificial blood vessel, the behavior of aggregations in a capillary has not been predicted. Thus we prepared artificial blood vessels including a capillary model, which was made of poly(vinyl alcohol) (PVA) by grayscale lithography method, with minimum diameter of the path of 0.

An accurate calibration method of ultrasound images by center positions of a metal ball.

This paper provides a novel method for three-dimensional tracking of ultrasound images. One of the issues to determine the position of a ultrasound image plane is the thickness of the image plane. The proposed methodology address the issue by the calibration phantom using a fiducial sphere with the diameter of 5.

Dependence of aggregate formation of microbubbles upon ultrasound condition and exposure time.

We have previously reported our attempts to control microbubbles (microcapsules) behavior in flow by primary Bjerknes force to increase the local concentration of the bubbles at a diseased part. However, there was a limitation in efficiency to propel bubbles of μm-order size. Thus we consider that forming aggregates of bubbles is effective to be propelled before entering into an ultrasound field by making use of secondary Bjerknes force under continuous ultrasound exposure.

Development of support system to handle ultrasound probe by coordinated motion with medical robot.

We have developed a support system using our ultrasound diagnosis robot, which is able to support manual handling of ultrasound probe in echography to alleviate fatigue of examiner. This system realizes a coordinated motion according to the motion of the probe, which is hold by the robot and is moved by an examiner. We have established four kinds of situations, which are initial fixation, coordinate motions with/without contact on the body surface, and automatic chase motion of an internal organ.

Study to prevent the density of microcapsules from diffusing in blood vessel by local acoustic radiation force.

We have already reported our attempt to constrain direction of microcapsules in flow owing to an acoustic radiation force. However, the diameter of capsules was too large not to be applied in vivo. Furthermore, acoustic radiation force affected only in focal area because focused ultrasound was used.

Fabrication and conductive properties of multilayered ultrathin films designed by layer-by-layer assembly of water-soluble fullerenes.

Fullerene ultrathin films were fabricated by layer-by-layer (LbL) assembly of an anionic fullerene C(61)(COO(-))(2) (FDCA) and poly(diallyldimethylammonium chloride) (PDDA) or a cationic fullerene C(60)C(2)H(4)N(CH(3))(2)(+) (FMAC) and poly(sodium 4-styrenesulfonate) (PSS). The dynamic light scattering and zeta-potential measurements revealed that both water-soluble fullerenes are stably dispersed as polyelectrolytes with a diameter of 20-70 nm for FDCA and 60-180 nm for FMAC in aqueous solutions. In spite of such large fullerene aggregates, the thickness of fullerene LbL films increased regularly by a few nanometers with each deposition, and the resultant LbL films were homogeneous.

Development of 3D space-sharing interface using augmented reality technology for domestic tele-echography.

We propose a domestic tele-echography system linking between the patient's home and a hospital because of the demand due to increase in the number of patients by aging society and recent progress in portable echography enabled us to develop this system. In previous researches three-dimensional position of the ultrasound probe was difficult to specify because a remote doctor observe the patient through a video camera. Therefore we have developed a reproduction system of the probe position and angle using the ARToolKit and GUI interface using OpenGL.

Active control of microcapsules in artificial blood vessel by producing local acoustic radiation force.

Micrometer-sized microcapsules collapse upon exposure to ultrasound. Use of this phenomenon for a drug delivery system (DDS), not only for local delivery of medication but also for gene therapy, should be possible. However, enhancing the efficiency of medication is limited because capsules in suspension diffuse in the human body after injection, since the motion of capsules in blood flow cannot be controlled.

Field testing of a remote controlled robotic tele-echo system in an ambulance using broadband mobile communication technology.

We report the testing of a mobile Robotic Tele-echo system that was placed in an ambulance and successfully transmitted clear real time echo imaging of a patient's abdomen to the destination hospital from where this device was being remotely operated. Two-way communication between the paramedics in this vehicle and a doctor standing by at the hospital was undertaken. The robot was equipped with an ultrasound probe which was remotely controlled by the clinician at the hospital and ultrasound images of the patient were transmitted wirelessly.

Development of recognition software of heart to find the standard cross section on echocardiography.

We have developed an algorithm to find standard cross sections (the long-axis view and the short-axis view) of the heart from successive echograms. We first divided an echogram into small spatial regions and detected the typical motion of the mitral valve by analyzing the brightness variation and correlation coefficient among the regions. We have obtained 95% accuracy in the position of the valve through time series echogram of 25 normal volunteers.

Robot-based tele-echography: the TER system.

This paper presents a master-slave robotized system enabling a remote echographic diagnosis. The expert holds a virtual probe placed on a haptic device; he moves this virtual probe in order to control the motion of the real probe positioned on the body of the patient located remotely. The real probe is placed on a lightweight and user-friendly slave robot and moved by it.

Development of a tele-echography system by using an echographic diagnosis robot.

We have developed a tele-diagnosis system of echography (tele-echography system) using an Echographic Diagnosis Robot. The examiner moves the robot by using a control device at a distance from the patient and obtaining the echogram and the situation around the patient. The examiner and the patient locations are connected by a wireless local area network.