Breast reconstruction surgery recovers the lost shape of the breast after mastectomy. However, a method to evaluate breast shape has not been established. Cosmetic evaluation of the breast shape is usually performed by the surgeon, and is therefore a subjective assessment. Moreover, no intraoperative navigation system is available for breast reconstruction surgery. To improve this situation, the present study proposes quantitative indicators of breast shape, and a support system for intraoperative breast reconstruction. First, the preoperative breast shape is measured using a 3-dimensional (3D) sensor (Kinect V2, Microsoft). Using the measured 3D breast shape, the local shape difference between the breast prior to mastectomy and the breast during reconstruction is converted to a 2-dimensional map, i.e., a shape difference map. The shape difference map is converted into 400 (20×20) grid squares for quantification of the local volume difference of the breast prior to mastectomy and after reconstruction. To present the shape difference map more intuitively to the surgeon, we then developed a system that projects the shape difference information onto the patient's body. The projection is performed by projection mapping using a tri-axial camera gimbal (Crane-M, Zhiyun) and a handy projector (ZenBeam E1, ASUS). Finally, the projection mapping data are registered using dedicated software. The developed system was evaluated on a phantom (a manikin simulating a human patient). Registration markers were placed on the upper, left-lower, and right-lower parts of the breast. After registering the projection data, the pre- and post-reconstruction data were compared using 3D viewer software (3D Builder). The registration time and positional error from the registration markers were evaluated during the experiment. The evaluation results were then analyzed using a nonparametric test. The validation experiment confirmed a significant difference between the viewer software and the developed registration software (p<0.01), suggesting that the system provides a useful quantitative index for breast shape evaluation.

The Amended Act on the Protection of Personal Information (Amended PIPA) requires medical information to be handled more securely. In large medical institutions, most medical information is stored in medical information systems. If the designed systems satisfy all the needs of using the medical information, there is no need to export clinical information from these systems. However, export of data is necessary for various purposes including research, public health and regional cooperation. Therefore, we investigated, constructed and evaluated a clinical information export environment in compliance with the Amended PIPA. Requirements for the export environment are as follows. 1. Only the data administrator can save or export data. 2. Depending on the type of data and the purpose of use, differences in criteria are established. 3. A correspondence table for pseudonymization is managed. The constructed export environment consists of the following elements:1. a server-based computing (SBC) environment, 2. a file transfer system, and 3. an image export system. By operating and evaluating the constructed export environment, we verified that the environment permits export of clinical information in compliance with the Amended PIPA.

We have developed a novel method to estimate the fine retinotopic map of the primary visual cortex from the intrinsic optical signal (IOS) induced by visual stimulation in an awake mouse. Unlike methods employing anesthesia, in order to reduce the burden on the animal, shortening the experimental time is an important requirement. During the awake state, eye movement, pupil diameter fluctuations, and brain background activity are present. Occurrence of eye movement blurs the retinal image. Excluding data under such circumstances in the synchronous average method is essential in conventional methods. In order to solve these problems, we focused on the strong correlation between the pupil diameter and the global signal (GS) of IOS and introduced a process to remove GS from IOS in preprocessing. This process improved the SN ratio of visual response in a single trial. We assumed that the response from the region of interest (ROI) of the cortex is described by the product sum of the retinal image and the receptive field function expressing the projection from the retina to the cortex. In this model, unlike the synchronous average method, the influence of eye movement can be expressed by shifting the retinal image. Therefore, all the response data can be used to estimate parameters, irrespective of the stimulation location or eye position. Additionally, in this method, the spatial resolution does not depend on the spatial resolution of the stimulation spot. The parameters of the receptive field function can be estimated using the nonlinear least squares method. By applying this method to real data, we obtained a retinotopic map with much higher spatial resolution than that obtained by conventional methods. Interestingly, structures similar to higher brain regions such as secondary visual cortex, which were previously observed only using invasive methods such as calcium imaging and electrophysiological method with electrode insertion in the mouse brain, were also visualized. These results demonstrate the usefulness of the proposed method with high spatial resolution.

Stochastic resonance (SR) is known as a phenomenon whereby detection of sub-threshold low level stimuli is improved by the addition of random noise at specific noise amplitudes in nonlinear threshold systems such as a neuron. In recent years, we reported observation of a SR-like phenomenon by the addition of periodic pulsatile electric stimuli at a specific pulse rate. The objective of this study was to investigate whether periodic pulsatile electric stimuli at a specific pulse rate enhance synaptic transmission of sub-threshold stimuli and induce periodic spike firings in a recurrent neuron model of four pyramidal neurons with a sub-threshold synaptic current. Computer simulations showed that while no spike firing was observed at lower pulse rates, periodic spike firings were observed as the pulse rate increased. However, with further increase in pulse rate, irregular spike firings were observed due to occurrence of unwanted spikes. Computer simulations also showed that the mean inter-spike interval tended to decrease as pulse rate of electric stimuli increased at specific pulse amplitudes. These results indicated that a pulse rate-dependent resonance phenomenon was present in a recurrent neuron model with sub-threshold synaptic current, and that desirable spike firing rate or mean inter-spike interval could be determined by setting appropriate pulse rate of the electric stimuli.