Muscle tissue swelling occurs immediately after exercise. Conventionally, this phenomenon has been evaluated by diagnostic imaging methods such as ultrasonic B-mode imaging. On the other hand, bioelectrical impedance analysis (BIA) is a simpler method to measure this phenomenon. In the BIA, changes in water volume inside and outside of muscle cells during exercise can be evaluated as changes in bioelectrical impedance (BI) . In this study, the local muscle fatigue was effectively measured using BIA by concentrating the current in a narrow area and the results were compared with muscle thickness measured by ultrasonic B-mode imaging. The measurement site was the upper arm, and the exercise condition was four sets of arm curl exercise. Measurements of upper arms were taken before exercise (base line:BL) and after each exercise set (post exercise:PE1-4) . BI was converted into external cell water resistance (R_ECW), internal cell water resistance (R_ICW), and their parallel resistance (R_ICW//R_ECW) . The results showed that R_ECW increased before PE1 and decreased after PE1. Therefore, exercise hyperemia was inferred to be a factor in muscle swelling after PE1. Then, the correlations between R_ECW, R_ICW, R_ICW//R_ECW and muscle thickness were calculated. Subsequently, a significant correlation was obtained between R_ICW//R_ECW and muscle thickness, especially after PE1.

Sound sources with ultrasound components have a positive effect on human beings, known as the hypersonic effect (HSE). To investigate the conditions causing HSE, changes in alpha waves in response to ultrasound were examined under these conditions:(1) almost similar ultrasound level from head to foot, (2) reduced ultrasound level below the neck, (3) Same conditions as (1), but use of noise-canceling headphones and noise masking, (4) increased in (2) such that the mean ultrasound pressure is equal to that of the super tweeter in the (1), (5) decreased sound pressure levels at the head and chest or only at the head, and (6) exposing ultrasound only to those body parts with a large area of the somatosensory cortex. Significant differences in alpha waves were found under conditions (1) and (3);however, no differences were found under conditions (2), (4), and (5). These results indicate that a wide distribution of ultrasound pressure on the body surface is re-quired for HSE to occur. HSE depends on the distribution, even at the same average sound pressure of the ultrasonic components. In addition, HSE improves the behavioral and psychological symptoms of dementia and reduces postprandial blood glucose elevations. The results of this study can be used for several HSE applications. This phenomenon also occurred when people had difficulty listening to music. This suggests that it is also effective for people with hearing loss.

Anterior cruciate ligament (ACL) injuries and reconstruction surgeries result in changes in the knee joint kinematics, necessitating improvements of the movement pattern of the injured knee joint via monitoring of the knee joint movement pattern. Visual estimation does not afford satisfactory accuracy during walking and running. Furthermore, three-dimensional (3D) motion capture devices using cameras have limited measurement ranges. These problems can be solved by wearable sensors. However, for consistent accuracy, wearable sensors need to be fixed to straps, tapes, or skin-tight garments. Straps and tapes may interfere with movement, while skin-tight garments may be difficult for patients with joint problems to wear. The attachment of existing wearable sensors to loose-fitting clothes has resulted in the reduction of the measurement accuracy. Therefore, this study aims to develop a bending angle sensor that can be attached to loose-fitting garments and to determine whether it has sufficient accuracy for monitoring knee joint motion patterns, especially during running rehabilitation after an ACL injury or a reconstruction surgery. The subjects were twenty healthy adult males who wore loose-fitting garments with the bending angle sensor attached to the right knee. They performed running tasks on a treadmill at speeds of 8, 10, and 12km/h for 90 s. The right knee joint motion was simultaneously measured with a 3D motion capture device and the bending angle sensor. The data for 60 s, excluding the 15 s after the start and before the end, were compared:MAE=5.8±1.1°, RMSE=7.0±1.4°, and R²=0.94±0.02. The results show that loose-fitting clothes attached to the bending angle sensor enables monitoring of the knee joint motion during running rehabilitation.

According to prior research, high-intensity endurance training (HIT) conducted more than twice a week significantly improves the maximum oxygen uptake (V_O2max), a marker of cardiorespiratory fitness, compared to low or moderate-intensity training. This training modality not only benefits athletes but also aids individuals with metabolic syndrome and circulatory and respiratory conditions, enhancing their quality of life. Despite these potentials, exploratory studies of exercise regimens with shorter durations, lower frequencies, and fewer sets remain insufficient; thus minimalistic HIT protocols remain under-investigated. In this research, our objective was to investigate the impact of an even less frequent, once-weekly, maximum effort high-intensity training (HIT) on cardiorespiratory function and exercise performance across various age groups. We enrolled 11 healthy participants (4 males and 7 females;age 36.9±16.7 years;height 163.4±11.7cm;weight 58.4±10.6kg) to participate in exhaustive training sessions for 8 weeks. The intensity was set at 80%of their maximum load reached in an initial ramp test (80%WR_max) . Before and after the training, participants underwent ramp test and head-up tilt (orthostatic load) test to assess adaptations in cardiorespiratory function during maximum exercise and circulatory adjustment to postural changes. Exercise performance was evaluated by maximum exercise duration until exhaustion (Exhaustion Time) . Post-training results indicated significant improvements in V_O2max (＋12%, p=0.02), ＋7.5% (p=0.026) WR_max＋12.7%, and Exhaustion Time. Furthermore, in the head-up tilt test, a significant increase in end-tidal CO₂ partial pressure (P_ETCO2) (＋17.5%, p=0.04) was observed in the supine position, and P_ETCO2 increased by ＋11.9% (p=0.03) while tidal volume decreased by -19.9% (p=0.02) in the tilt position. Although no interaction was found in ANOVA, significant Primary effects of training and condition were observed for P_ETCO2. Our findings suggest that once-weekly HIT to maximum exertion enhances cardiorespiratory function and exercise performance. No changes in parameters maintaining blood pressure were observed during the head-up tilt test. These findings may be valuable for future development of efficient exercise training programs for wider age groups.

In recent years, percutaneous coronary intervention (PCI) has become established as a treatment for angina pectoris and acute coronary syndromes due to technological advances and improved devices. However, highly calcified lesions, which cause stent failures after stent implantation, are one of the major problems in PCI. Therefore, optical coherence tomography (OCT) is used to determine the thickness of calcification in the vessel wall to guide the treatment strategy for calcified lesions. Although OCT can evaluate the angle and thickness of calcification, it requires skilled reading and is only available in a limited number of centers. In this study, we focused on the amount of calcification measurable by CT coronary angiography (CCTA) and used CCTA to delineate slices of all calcified areas and measure their volumes. Similarly, we used OCT images to measure the angle of calcification and the thickness of calcium in the vessel wall in all slices where calcification was observed. In 18 patients undergoing PCI for angina pectoris, calcification volume on CCTA images was significantly positively correlated with calcification angle and thickness summation on OCT images. These results suggest that CCTA calcification volume may allow estimation of calcification severity by OCT and may serve as a noninvasive index to complement OCT calcification assessment.

The development of cuffless blood pressure monitoring devices is attracting attention. The method of measuring vessel diameter from ultrasound A-mode waveforms is expected to be applied to daily blood pressure measurement due to the simplicity of the device. On the other hand, there is a problem in that the received intensity of the reflected wave from the blood vessel wall decreases due to displacement caused by body movement, resulting in incorrect measurement of the vessel diameter. In this paper, we examine how displacement of the positional relationship between the sensor and the blood vessel affects the measurement of blood vessel diameter and present a solution to the sensitivity reduction caused by angular displacement in the direction of the vessel axis by sending ultrasonic waves radially in the direction of the vessel axis. As a verification, a prototype sensor with an acoustic lens was fabricated. Evaluation of the sensor using a silicone resin tube model of a blood vessel showed that it maintained received intensity of about 50%of the strongest received intensity over a range of ±10°and the calculated blood vessel diameter was accurate to±0.05mm over a range of ±10°. Since this technology does not require a complex system, it is expected to be applied to devices that daily blood pressure measurement without the patient’s consciousness.

An endoscope is a device that allows an observation for the inside of objects that are difficult for humans to see directly by inserting a thin tube with an optical system. By the endoscope, doctors can observe the inside of the human body in real time and perform treatment by using treatment instruments through the forceps channel installed inside the endoscope. In this manuscript, the author explains the history of endoscope, the basic structure of the endoscope system, the fields of use and endoscope types, and the technology used.