著者

Kiyoyuki Chinzei Akinobu Shimizu Kensaku Mori Kanako Harada Hideaki Takeda Makoto Hashizume Mayumi Ishizuka Nobumasa Kato Ryuzo Kawamori Shunei Kyo Kyosuke Nagata Takashi Yamane Ichiro Sakuma Kazuhiko Ohe Mamoru Mitsuishi

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.7, pp.118-123, 2018 (Released:2018-05-24)

参考文献数

3

被引用文献数

30

---

AI-based medical and healthcare devices and systems have unique characteristics including 1) plasticity causing changes in system performance through learning, and need of creating new concepts about the timing of learning and assignment of responsibilities for risk management; 2) unpredictability of system behavior in response to unknown inputs due to the black box characteristics precluding deductive output prediction; and 3) need of assuring the characteristics of datasets to be used for learning and evaluation. The Subcommittee on Artificial Intelligence and its Applications in Medical Field of the Science Board, the Pharmaceuticals and Medical Devices Agency (PMDA), Tokyo, Japan, examined “new elements specific to AI” not included in conventional technologies, thereby clarifying the characteristics and risks of AI-based technologies. This paper summarizes the characteristics and clinical positioning of AI medical systems and their applications from the viewpoint of regulatory science, and presents the issues related to the characteristics and reliability of data sets in machine learning.

著者

Kanchi Ito Yuki Osawa Kenta Kaneko Yutaka Kikuchi Masato Odagaki

出版者

一般社団法人日本生体医工学会

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.6, pp.42-47, 2017 (Released:2017-04-03)

参考文献数

10

---

Two different experiments utilizing the motor imagery of finger movement were conducted. We attempted to reveal the difference in corticospinal excitability between tonic contraction (TC) and rhythmic movement (RM) by transcranial magnetic stimulation (TMS). The magnetic coil was placed over the subject’s primary motor cortex to elicit motor-evoked potentials (MEPs) by TMS. We have previously shown that the MEP amplitude is modulated by the frequency of active and passive finger movements. We hypothesized that visual feedback affects the corticospinal excitability. In the present study, the subject observed both TCs and RMs, and the MEP amplitudes elicited by TMS during both tasks were analyzed to assess changes in corticospinal excitability influenced by the motor imagery. A mirror box was used to show the subject the finger movement executed by a third person as if it were his own finger movement. For the TC task, the third person performed a pinching task consisting of TC of the index finger and thumb. The subject received visual feedback of the TC in the mirror. For the RM task, the subject observed the mirror while the third person performed RM of the index finger until TMS was applied. The frequencies of finger movement were 0.5, 1, 2, 3, and 4 Hz. The resulting MEP amplitudes for the RM task at movement frequencies of 2, 3, and 4 Hz were significantly lower than that for the TC task. These results indicate that corticospinal excitability is increased by visual feedback of TC but is modulated by that of RM.

著者

Kenzo Akazawa Tomoko Ichinose Kakuko Matsumoto Masayoshi Ichie Tsutomu Masuko Ryuhei Okuno

出版者

一般社団法人日本生体医工学会

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.6, pp.1-7, 2017 (Released:2017-01-25)

参考文献数

11

被引用文献数

4

---

We have developed a novel electronic musical instrument with a pre-programmed score, called “Cymis,” to help the disabled enjoy playing musical pieces. In 2008, field experiments commenced at a nursing home (capacity 52 clients; average age 58.6; cerebral palsy 32 clients). The purpose of the present study was to demonstrate that Cymis is useful and effective for helping the severely disabled maintain or improve their quality of life. First, the accessibility of Cymis was revealed by the fact that 34 clients (63%) played Cymis for an average of 5.6 years. Second, each client’s progress in performance, which possibly reflects improvements of upper-limb motor control function, was examined for the longest duration of over 7 years. Among 31 clients, 13 (42%) showed progress, 17 (55%) showed no change (5 of whom showed progress initially but then regressed to their original status), and 1 (3%) revealed deterioration in condition. Third, psychological effects were measured using an original Face Scale before and after playing Cymis, for a total of 395 performances by 38 clients. Clients became happier in 208 performances (53%), showed no changes in 139 (35%), and became sadder in 48 (12%). Finally, with respect to their care plans, 19 of 52 clients (37%) selected Cymis in 2015, and this number itself implies the importance of Cymis. Basic reasons for selection were investigated by care workers’ assessments from mental and psychological perspectives. In conclusion, Cymis was useful, effective, and attractive to the disabled; it permitted them to enjoy playing music that might not otherwise be possible, and some evidence of therapeutic effect was found.

著者

Osamu Uehara Toshimasa Kusuhara Takao Nakamura

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.12, pp.1-8, 2023 (Released:2023-02-03)

参考文献数

19

被引用文献数

2

---

Deterioration of skin barrier function causes symptoms such as allergies because it allows various chemical substances to enter the human body. Quantitative evaluation of the thickness and water content of the stratum corneum is useful as a measure of skin barrier function in fields such as dermatology, nursing science, and cosmetics development. The stratum corneum is responsible for most of the skin barrier function, and this function has conventionally been evaluated using transepidermal water loss (TEWL). In this paper, we propose a new model for estimation of TEWL from measurements of the thickness of the stratum corneum and water content of the surface of the stratum corneum, and discuss the results of the measurements. By measuring the thickness and water content of the stratum corneum using confocal laser microscopy and confocal Raman spectroscopy, respectively, and examining the relationship of these variables with TEWL, we established a new potential model for estimating TEWL from these two variables. The correlation coefficient of the validation data was 0.886 and the root mean squared error was 8.18 points. These findings indicate the feasibility of qualitative evaluation of TEWL by measuring the thickness and water content of the stratum corneum.

著者

Tianyi WANG Shima OKADA Masayuki ENDO Masaaki MAKIKAWA Yuko OHNO

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.10, pp.11-17, 2021 (Released:2021-01-26)

参考文献数

34

被引用文献数

3 4

---

Hiesho is the condition of having a cold sensation in one's hands or feet. This is a well-known health problem for young Asian females. However, the definition of Hiesho is still controversial. In this study, we aimed to develop a quantitative and non-invasive approach to determine Hiesho. Sixty-three young females participated in this research. Temperature difference (ΔT) between the forehead and foot sole was utilized to define Hiesho or non-Hiesho condition, and the result was crosschecked with that of a self-reported questionnaire. Central systolic blood pressure and augmentation index were measured to evaluate subjects' physiological indicators. The results of the questionnaire showed that 49% of young females (31 of 63 people) reported Hiesho. There was a significant difference in ΔT between non-Hiesho and Hiesho (1.85℃ and 5.55℃, respectively, p < 0.01). After cross-checking with the self-reported questionnaire, ΔT of 3.64℃ demonstrated acceptable reliability and accuracy for defining Hiesho. Central systolic blood pressure and augmentation index were not different between Hiesho and non-Hiesho. In conclusion, young females with Hiesho had drastically different temperatures at the forehead and foot sole. The temperature difference between the forehead and foot could be used as a quantitative and objective parameter for defining Hiesho.

著者

Toshiyo Tamura Ming Huang Tatsuo Togawa

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.7, pp.88-99, 2018 (Released:2018-04-12)

参考文献数

44

被引用文献数

12 49

---

Wearable thermometers are popular devices for measuring body temperature during fever, as well as for monitoring basal temperature in women. They are easy to handle, inexpensive, accurate and provide continuous recordings. Most wearable thermometers are connected to a smart phone or tablet to display data. Many types of wearable thermometer are available, such as touch, patch and invisible (radiometric) types. In this review, we describe and discuss currently available wearable thermometers.

著者

Richard AJ Wain Nicolas J Gaskell Andrew M Fsadni Jonathan Francis Justin PM Whitty

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.8, pp.63-77, 2019 (Released:2019-02-15)

参考文献数

80

被引用文献数

1

---

Simulation using computational methods is well-established for investigating mechanical and haemodynamic properties of blood vessels, however few groups have applied this technology to microvascular anastomoses. This study, for the first time, employs analytic and numeric models of sutured and coupled microarterial anastomoses to evaluate the elastic and failure properties of these techniques in realistic geometries using measured arterial waveforms. Computational geometries were created of pristine microvessels and microarterial anastomoses, performed using sutures and a coupling device. Vessel wall displacement, stress, and strain distributions were predicted for each anastomotic technique using finite element analysis (FEA) software in both static and transient simulations. This study focussed on mechanical properties of the anastomosis immediately after surgery, as failure is most likely in the early post-operative period. Comparisons were also drawn between stress distributions seen in analogous non-compliant simulations. The maximum principal strain in a sutured anastomosis was found to be 84% greater than in a pristine vessel, whereas a mechanically coupled anastomosis reduced arterial strain predictions by approximately 55%. Stress distributions in the sutured anastomoses simulated here differed to those in reported literature. This result is attributed to the use of bonded connections in existing studies, to represent healed surgical sites. This has been confirmed by our study using FEA, and we believe this boundary condition significantly alters the stress distribution, and is less representative of the clinical picture following surgery. We have demonstrated that the inertial effects due to motion of the vessel during pulsatile flow are minimal, since the differences between the transient and static strain calculations range from around 0.6–7% dependent on the geometry. This implies that static structural analyses are likely sufficient to predict anastomotic strains in these simulations. Furthermore, approximations of the shear strain rate (SSR) were calculated and compared to analogous rigid-walled simulations, revealing that wall compliance had little influence on their overall magnitude. It is important to highlight, however, that SSR variations here are taken in isolation, and that changing pressure gradients are likely to produce much greater variation in vessel wall strain values than the influence of fluid flow alone. Hence, a formal fluid-structure interaction (FSI) study would be necessary to ascertain the true relationship.

著者

Ryutaro Kasedo Atsuhiko Iijima Kiyoshi Nakahara Yusuke Adachi Isao Hasegawa

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.10, pp.26-31, 2021 (Released:2021-02-11)

参考文献数

15

---

The rhythm of vocalizing a written language depends on a merge process that combines meaningless linguistic units into a meaningful lexical unit, word, or Bunsetsu in Japanese. However, in most previous studies, written language was presented to the participants in lexical units (word-by-word) with explicit inter-word (or inter-Bunsetsu) marks or spacing. Therefore, it has been difficult to conduct psychophysical assessment of the participants' own speed in segmenting meaningful units from unstructured written language when reading. Here, we hypothesized that the spontaneous reading speed of Japanese readers reflects their own punctuation process, even when sentences are written without punctuation marks or spaces. To test this hypothesis, we developed a new “self-paced sequential letterstring reading task,” which visually presents sentences letter-by-letter. The task required participants to push a button to proceed to the next letter at their own pace, hence allowing evaluation of the reaction time (RT) to individual letters. We found that the average RT decreased parametrically as the position of the letter approached the end of a Bunsetsu. Moreover, the RT increased drastically at the last letter completing the Bunsetsu. Participants were not shown any punctuation marks and not instructed to explicitly recognize the punctuations during reading. Therefore, these effects strongly suggest that the implicit and spontaneous punctuation is the origin of the rhythm in reading. These results show that spontaneous punctuation of letterstring affects the reading speed. The task we have developed is a promising tool for revealing the temporal dynamics of natural reading, which opens a way to shape the fluency of script-to-speech human interfaces.

著者

Kazuhiko Yamashita Tomoko Yamashita Mitsuru Sato Masahiro Inoue Yoshimasa Takase

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.9, pp.117-124, 2020 (Released:2020-07-30)

参考文献数

27

被引用文献数

3

---

Chronic diseases such as diabetes, hypertension, and hyperlipidemia increase the medical costs for middle-aged and elderly people, thus requiring preventive intervention. Monitoring, maintaining, or increasing the number of steps walked per day could be expected to effectively reduce medical costs. We evaluated the medical costs for chronic diseases after the implementation of a step count monitoring system with an information communication technology that we hypothesized would efficiently decrease medical costs. We enrolled 342 subjects in the intervention group. An additional 1,025 subjects were selected as controls by matching with the intervention group for age, gender, and total medical costs accumulated in the year prior to the study. The subjects in the intervention group were provided with pedometers that were used with reading devices stationed throughout the city. The duration of the intervention was 18 months. The subjects were given health points based on their activity performance improvements such as the number of steps they walked. The medical costs for the 18 months before and afer the intervention were compared. The effect of cost reduction was evaluated by comparing the percent increase in medical cost from before to after intervention between the control group and the intervention group. After the intervention period, the medical costs increased in the control group but not in the intervention group. The step counts for the first three months and the last three months of the intervention period were assessed, and the results showed that an average step count of 8000 steps was maintained throughout the intervention period. Assuming that the control group showed a natural increase in medical costs, the results suggest that the natural increase in medical costs was suppressed in the intervention group during the intervention period as a result of using the pedometer technology and health points. Therefore, we found that encouraging the participants to proactively participate in walking was an effective strategy.

著者

Lulin Dai Jun-ya Okamura Gang Wang

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.9, pp.93-99, 2020 (Released:2020-05-15)

参考文献数

15

---

Neuroscientists usually investigate stimulus selectivity by using a stimulus set and identifying the stimulus that evokes the largest electrophysiological responses averaged over a certain time period. However, the visual environment, and hence the brain activity, changes all the time. A method with sufficiently high temporal resolution for the investigation of dynamic changes in stimulus selectivity is desired. Here, we propose a method by dividing the usual time window for spike rate calculation into multiple smaller time windows. We applied this method to the analysis of temporal change in stimulus selectivity of inferotemporal (IT) cells in macaque monkey recorded previously using microelectrode while they were performing an object discrimination task, in which one object had to be discriminated from others regardless of change in viewing angle. The IT cortex is located at the last stage of the ventral cortical pathway, and is important for object recognition and discrimination. The proposed method theoretically possesses temporal resolution in millisecond order. We demonstrated its ability by following the changes in stimulus selectivity with temporal resolution as high as 20 ms. Furthermore, we divided the response time window into early phase and late phase. In each phase, single cell responses to images (4 objects × 4 views; 16 images in each of the stimulus set) were compared to identify the stimulus evoking the largest response. When comparing the early and late phases, 40% of the cells showed the largest response to the same stimulus (same object and same viewing angle); 13% of the cells showed the largest response to the same object but at different viewing angles; 20% of the cells showed the largest response to different objects at the same viewing angle; and 20% of the cells showed the largest response to different objects at different viewing angles. The dynamic change of stimulus selectivity from early phase to late phase may provide important information about the underlying neuronal mechanism for object recognition. Successful application of the proposed method to the analysis of IT cell activity demonstrates the validity and usefulness of the method.

著者

Yoshio Tsuchiya Takayuki Tanaka Tamotsu Kamishima

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.9, pp.181-188, 2020 (Released:2020-09-19)

参考文献数

21

被引用文献数

2

---

Lumbar loading causes increased intervertebral pressure and is an important factor in low back pain. However, it is difficult to quantitatively judge the actions that affect lumbar load and the magnitude of lumbar load increase. Low back pain occurs not only in the workplace but also during activities of daily living. Therefore, it is necessary to investigate the factors inducing low back pain by measuring movements in various planes and determining the magnitude of the lumbar load. Accordingly, the lumbar spine should be examined during various movements. Several studies have examined vertebral bodies in the anteflexion posture. However, the relationship between body flexion angle and vertebral body angle during lateral flexion and rotation remains unknown. In this study, we proposed an estimation method for changes in vertebral body angle during lateral flexion and rotation in the lumbosacral region using a wearable sensor system we previously developed. The accuracy of the proposed estimation method was evaluated and demonstrated using X-ray images.

著者

Yusuke Yuasa Kenji Suzuki

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.8, pp.85-91, 2019 (Released:2019-02-23)

参考文献数

15

被引用文献数

1 10

---

Asthma is a chronic respiratory disease, in which symptoms appear or intensify suddenly, even when patients are being monitored by doctors. Continuous measurement is important to monitor a patient's breathing without missing asthma attacks. In this study, we propose a method of continuous breathing monitoring in daily life using a wearable device. There are several studies using microphones to continuously monitor breathing during activities, which show various possibilities of extracting qualitative characteristics related to asthma. Other studies on breathing measurement using accelerometers or belts have achieved breathing detection and measurement without ambient acoustic noises. Taking advantage of the breathing sound and chest movement signals, they are simultaneously acquired using a chest-mounted device, which consists of a microphone, a photoreflector, and a flexible cover. Various acoustic noises and body movements are present in the environment. Thus, acquiring these two different signals in a complementary manner makes it easier to detect breathing in daily life. For monitoring asthma, we focused on detecting the breathing phases. Most of the asthma symptoms appear during the exhalation phase. Thus, phase detection plays an important role as an asthma symptom identifier. We developed a new algorithm for breathing phase measurement using both acquired signals. The algorithm is based on the periodicity of the chest movement signal. Breathing sounds are analyzed considering their frequency characteristics. In this paper, the basic performance of the proposed device in an experimental condition which is quiet and without participant movements is examined. The results of performance evaluation confirm that the left medial side of the second intercostal space is appropriate for placing the device and studying the correlation between breathing sound amplitude and tidal volume, which implies a potential to acquire tidal volumes. The phase measurement experiment shows that chest movement can be used for estimating the breathing period. The portable system developed can measure breathing in external conditions and tracking the wearer's location. Making the system portable expands the measurable situations and facilitates an acquisition of time and location information, which is useful in identifying the causes of asthma attacks.

著者

Yasuo Terasawa Hiroyuki Tashiro Yukari Nakano Takashi Tokuda Jun Ohta

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.5, pp.137-141, 2016 (Released:2017-01-12)

参考文献数

19

被引用文献数

2 5

---

Implantable neural stimulators have recently attracted attention because of their potential applicability to the treatment of sensory neural disorders such as hereditary hearing loss and retinitis pigmentosa. However, the requirements for stimulation electrodes tend to be contradictory in some applications that require transmission of complex information to the nervous system, such as cochlear implants and retinal prostheses. They have to be sufficiently small to realize fine interfacing with the nervous system while remaining sufficiently large to inject enough charge to stimulate neurons without causing an irreversible electrochemical reaction. One solution to these requirements is to employ three-dimensional (3D) instead of planar electrodes. However, in conventional photolithography, the available material and size for fabricating electrodes are greatly limited. To overcome these limitations, we propose a novel fabrication process for stimulation electrodes, using mechanical micromachining. Using 3D bullet-shaped electrode increased the surface area by 3.6 times compared to conventional planar electrode with the same diameter. The proposed electrode, which was developed for retinal prostheses, showed sufficient charge injection capacity (CIC) to evoke light perception (phosphene) for blind patients. Furthermore, the CIC and electrode surface morphology remained stable during a six-month period of current pulsing in phosphate-buffered saline, which suggests suitability for chronic neural stimulation. The cause of the variance in the measured CIC and future applications of the proposed 3D electrodes were also considered.

著者

Hiroyuki Tashiro Yasuo Terasawa Mariko Kuwabara Koji Osawa Takashi Tokuda Jun Ohta Takashi Fujikado

出版者

Japanese Society for Medical and Biological Engineering

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.6, pp.8-14, 2017 (Released:2017-02-17)

参考文献数

17

被引用文献数

1 2

---

We have developed retinal prosthetic devices based on suprachoroidal-transretinal stimulation (STS). The effectiveness and safety of such novel devices are confirmed by in vitro and in vivo tests based on scientific knowledge. Animal testing is especially important because it demonstrates the total safety of the device. We successfully developed a long-term evaluation system with automatic stimulation and measurement of electrochemical characteristics in freely moving rabbits. This system allows evaluation of long-term safety and change in electrochemical characteristics. In addition, we conducted a pilot evaluation of the safety of STS using bullet-shaped electrodes in rabbits. No obvious injuries were observed in all examinations. However, the array moved away from the retina in a few rabbits. Visual and electrical evoked potentials (EEPs) were recorded after three-month implantation. The function of the retinal neurons around the electrode is assumed to be maintained because EEPs were observed after three-month stimulation. However, the evoked potentials become indistinct with time in some rabbits. The development of implantable recording electrode capable of long-term evaluation is necessary for assessing the function of retina exposed to electrical stimulation. Long-term safety and change in electrochemical characteristics can be confirmed easily using this system. No histological difference was observed between the active and inactive electrodes, suggesting that the amount of charge used in the study can be safely injected. The charge injection capacity (CIC) of these electrodes provides an indication of the safety threshold for STS. The electrode array should have a curvature to fit the eyeball to avoid movement of the array away from the retina. The electrode height is slightly greater compared to the sclera thickness. Accordingly, methods to enhance the CIC vs. geometrical surface area are required if the electrode height is reduced. We were able to obtain an indication of the required performance for the stimulation electrode based on the safe charge injection for STS (CIC of approximately 90 μC/cm2 in PBS) and establish a system capable of evaluating safety and durability of retinal prostheses for long-term stimulation.

著者

Mariko Kuwabara Hiroyuki Tashiro Yasuo Terasawa Koji Osawa Takashi Tokuda Jun Ohta Takashi Fujikado

出版者

一般社団法人日本生体医工学会

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.6, pp.59-67, 2017 (Released:2017-05-31)

参考文献数

25

被引用文献数

3

---

Development of direct neural interface (DNI) including visual prostheses absolutely requires confirmation of their long-term safety and stability. Functional evaluation by electrically evoked potentials (EEPs) is effective in this regard, although the recording system must be stable for chronic use. In addition, control of anesthetic depth is important for stable recording of the evoked potentials. The purpose of this study was to develop a chronically implanted electrode capable of recording visual evoked responses safely during repeated anesthesia over long periods, which would allow more effective safety evaluations of not only visual prostheses but also DNI. We developed two types of electrodes, and implanted them into rabbits. A general screw electrode was used for comparison with the novel electrodes. Structurally, the newly developed platinum (Pt) ball-tip screw electrode consisted of a plastic screw with smoothly surfaced Pt balls on the tip. The depth of implantation into the brain was adjustable via a threaded insert installed in the skull. The newly developed platinum/iridium (Pt/Ir) ball-tip planar multi-electrode array (MEA) comprised Pt/Ir ball electrodes placed in a two-dimensional lattice pattern, which was implanted just beneath the skull. These electrodes recorded variations in visual evoked potentials (VEPs) in response to 20 J flash stimuli over a period of 48 weeks. After 48 weeks of implantation, the ability of the electrodes to continue recording EEPs was confirmed (500 µA, 500 µs, cathodic first biphasic). During the recording of VEPs and EEPs, stable anesthesia was maintained with isoflurane (end-tidal 2.4%). The depth of anesthesia using isoflurane could be adjusted safely, and allowed stable recording of evoked potentials throughout the long-term study. However, stable recording using the general screw electrode was possible only for a short period. We also obtained stable latency and N1 amplitude readings over the 48 weeks using the newly developed electrodes, and successfully recorded EEPs after the 48-week period. These results suggest that the novel electrodes work well over the entire duration of the study, and may allow assessment of long-term safety and stability of not only visual prostheses, but also other devices utilizing brain machine interfaces or direct neural interfaces.

著者

Kaori Shikano Keisuke Chiba Shogo Miyata

出版者

一般社団法人日本生体医工学会

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.4, pp.170-178, 2015 (Released:2015-11-25)

参考文献数

19

被引用文献数

5

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Hypertrophic scars are frequently observed at wound sites that had been subjected to cyclical stretch stimuli, such as skin of the anterior chest wall and lower abdomen. Previous studies found that cyclic stretch modulated fibroblast infiltration and collagen fiber remodeling compared with static culture conditions. However, these studies used homogeneous cultures that poorly replicated the physiological organization at the wound site. Similar to early studies, we hypothesized that cyclic stretch modulated fibroblast infiltration and collagen fiber remodeling compared with static culture conditions. However, we replaced the homogeneous culture condition used in previous studies with a novel two-gel wound model consisting of an inner decellularized collagen gel mimicking the wound site and an outer fibroblast gel simulating the epidermis. These models were then subjected to either 1-Hz uniaxial cyclical stretch for 3 h each day or were placed under static culture conditions. After day 4 in culture, we found two significant differences between specimens under the cyclic stretch conditions and those under static conditions. First, there were fewer fibroblast infiltrates in the inner wound-mimicking gel in cyclically stretched specimens than in statically stretched specimens. Second, the microstructure and orientation of collagen fibers in cyclically stretched specimens differed histologically from those in static culture. These results add to the growing evidence that cyclical stretch modulates the wound-healing process.