Body surface registration considering individual differences with non-rigid iterative closest point.

Purpose: In telemedicine such as remote auscultation, patients themselves or non-medical people such as patient's parents need to place the stethoscope on their body surface in appropriate positions instead of the physicians. Meanwhile, as the position depends on the individual difference of body shape, there is a demand for the efficient navigation to place the medical equipment.

Methods: In this paper, we have proposed a non-rigid iterative closest point (ICP)-based registration method for localizing the auscultation area considering the individual difference of body surface.

Towards fully automated robotic platform for remote auscultation.

Background: Since most developed countries are facing an increase in the number of patients per healthcare worker due to a declining birth rate and an ageing population, relatively simple and safe diagnosis tasks may need to be performed using robotics and automation technologies, without specialists and hospitals. This study presents an automated robotic platform for remote auscultation, which is a highly cost-effective screening tool for detecting abnormal clinical signs.

Method: The developed robotic platform is composed of a 6-degree-of-freedom cooperative robotic arm, LiDAR camera, and a spring-based mechanism holding an electric stethoscope.

A visualization method for a wide range of rising temperature induced by high-intensity focused ultrasound using a tissue-mimicking phantom.

Purpose: High-intensity focused ultrasound (HIFU) treatment requires prior evaluation of the HIFU transducer output. A method using micro-capsulated thermochromic liquid crystal (MTLC) to evaluate the temperature distribution in the media during HIFU exposure has been previously developed. However, the color-coded temperature range of commercial MTLC is approximately 10 °C, which is insufficient for temperature measurement for HIFU exposure.

The feasibility of a noise elimination method using continuous wave response of therapeutic ultrasound signals for ultrasonic monitoring of high-intensity focused ultrasound treatment.

Purpose: In this study, the robustness and feasibility of a noise elimination method using continuous wave response of therapeutic ultrasound signals were investigated when tissue samples were moved to simulate the respiration-induced movements of the different organs during actual high-intensity focused ultrasound (HIFU) treatment. In addition to that, the failure conditions of the proposed algorithm were also investigated.

Methods: The proposed method was applied to cases where tissue samples were moved along both the lateral and axial directions of the HIFU transducer to simulate respiration-induced motions during HIFU treatment, and the noise reduction level was investigated.

Investigation of feasibility of noise suppression method for cavitation-enhanced high-intensity focused ultrasound treatment.

In high-intensity focused ultrasound (HIFU) treatment, a method that monitors tissue changes while irradiating therapeutic ultrasound is needed to detect changes in the order of milliseconds due to thermal coagulation and the presence of cavitation bubbles. The new filtering method in which only the HIFU noise was reduced while the tissue signals remained intact was proposed in the conventional HIFU exposure in our preliminary study. However, HIFU was irradiated perpendicular to the direction of the imaging ultrasound in the preliminary experiment, which was believed to be impractical.

Histological observation for needle-tissue interactions.

We histologically investigated tissue fractures and deformations caused by ex vivo needle insertions. The tissue was formalin-fixed while the needle remained in the tissue. Following removal of the needle, the tissue was microtomed, stained, and observed microscopically.

Coaxial needle insertion assistant for epidural puncture effect of lateral force on needle.

We validated the effectiveness of a coaxial needle insertion assistant under the condition that the needles were laterally deformed. The coaxial needle insertion assistant separates the cutting force at the needle tip from shear friction on the needle shaft, and haptically display it to a user in order to assists her/his perception during epidural puncture. An outer needle covers the side of an inner needle, preventing the shear friction from acting on the inner needle.

Coaxial needle insertion assistant with enhanced force feedback.

Many medical procedures involving needle insertion into soft tissues, such as anesthesia, biopsy, brachytherapy, and placement of electrodes, are performed without image guidance. In such procedures, haptic detection of changing tissue properties at different depths during needle insertion is important for needle localization and detection of subsurface structures. However, changes in tissue mechanical properties deep inside the tissue are difficult for human operators to sense, because the relatively large friction force between the needle shaft and the surrounding tissue masks the smaller tip forces.

Experimental evaluation of a coaxial needle insertion assistant with enhanced force feedback.

During needle insertion in soft tissue, detection of change in tissue properties is important both for diagnosis to detect pathological tissue and for prevention to avoid puncture of important structures. The presence of a membrane located deep inside the tissue results in a relatively small force variation at the needle tip that can be masked by relatively large friction force between the needle shaft and the surrounding tissue. Also, user perception of force can be limited due to the overall small force amplitude in some applications (e.

MRI-compatible micromanipulator: Positioning repeatability tests & kinematic calibration.

In this paper, we report results from positioning repeatability tests and kinematic calibration of our magnetic resonance imaging (MRI)-compatible micromanipulator. This manipulator provides medical and biological scientists with the ability to concurrently manipulate and observe micrometer size objects inside an MRI-gantry. We have already reported on its design, implementation, and the results of preliminary testing of MRI compatibility.

MRI-compatible micromanipulator; design and implementation and MRI-compatibility tests.

In this paper, we present a magnetic resonance imaging (MRI)-compatible micromanipulator, which can be employed to provide medical and biological scientists with the ability to concurrently manipulate and observe micron-scale objects inside an MRI gantry. The micromanipulator formed a two-finger micro hand, and it could handle a micron-scale object using a chopstick motion. For performing operations inside the MRI gantry in a manner such that the MRI is not disturbed, the system was designed to be nonmagnetic and electromagnetically compatible with the MRI.