Kazuhiko Yamashita

Prof. Kazuhiko Yamashita


Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 May 2018 in Surgical Innovation
Verified
Journal Article
Open access
KYKazuhiko Yamashita
Kazuhiko Yamashita
KKKaori Kusuda
Kaori Kusuda
YIYoshitomo Ito
Yoshitomo Ito
MKMasaru Komino
Masaru Komino
KTKiyohito Tanaka
Kiyohito Tanaka
YSYoshiki Sawa
Yoshiki Sawa
Background. Surgical instrument retention and instrument breakage compromise surgery quality and lead to medical malpractice. We developed an instrument tracking system that could alert surgeons to instrument retention during surgery and monitor instrument use to reduce the risk of breakage. Methods. This prospective, experimental clinical trial included 15 patients undergoing inguinal hernia surgery or lumpectomy under general anesthesia at Saiseikai Kurihashi Hospital. Radiofrequency identification (RFID)-tagged surgical instruments were used, and a detection antenna was placed on a mayo stand during the operation. We analyzed the 1-loop detection ratio (OLDR)—that is, the capability of the antenna to detect devices in a single reading—and the total detection rate (TDR)—that is, the data accumulated for the duration of the operation—of the RFID-tagged instruments. Results. Data analysis revealed that the OLDR was 95% accurate, whereas the TDR was 100% accurate. The antenna could not detect the RFID tag when there was interference from electrocautery noise radiation, and 6% of instrument movement was undetected by the antenna; however, the TDR and instrument use were detected at all times. Conclusions. Surgical instruments can be tracked during surgery, and this tracking can clarify the usage rate of each instrument and serve as a backup method of instrument counting. However, this study was conducted on a small scale, and RFID tags cannot be attached to small surgical instruments used in complex operations such as neurosurgery. Further efforts to develop a tracking system for these instruments are warranted.

14 March 2019 in BMC Geriatrics
Verified
Journal Article
Open access
PDF file
TYTomoko Yamashita
Tomoko Yamashita
KYKazuhiko Yamashita
Kazuhiko Yamashita
CRChugo Rinoie
Chugo Rinoie
YTYoshimasa Takase
Yoshimasa Takase
MSMitsuru Sato
Mitsuru Sato
ASAnd Yoshiki Sawa
And Yoshiki Sawa
Abnormalities in the feet and toenails are common among the elderly and may increase the risk of falls. This study aimed to investigate the changes in toe-gap force, knee-gap force, foot pressure distribution, the ability to perform activities of daily living, subjects’ feelings and behaviors, and physical function resulting from daily lifestyle modification and foot care. The study participants included 74 elderly adults (mean age 80.3 ± 7.5 years) with foot problems who had been divided into three groups based on Japan’s nursing care insurance system levels: certified ineligible for support, eligible for support, or eligible for long-term care. Additionally, a control group of 106 elderly adults in good health was recruited. The differences between the intervention and control groups was examined using the Student’s t-test, and differences between the three intervention subgroups and the control group were examined using one-way analysis of variance. After intervention, abnormalities in the participants’ feet and toenails improved. Significant increases in lower-limb muscle strength were observed, and foot pressure distribution had improved. The foot-care intervention significantly improved lower-limb muscle strength and decreased the risk of falling, even in elderly adults whose physical function had deteriorated. In frail elderly adults, care of the feet and toenails can improve lower-limb muscle strength and foot pressure distribution. In addition, the individuals’ social participation increased, and their behavior improved. University hospital Medical Information Network- Clinical Trials (UMIN-CTR) with the number: UMIN000034742 . Registration date: 11/01/2018.

18 July 2001 in Electrical Engineering in Japan
Verified
Journal Article
Open access
PDF file
KYKazuhiko Yamashita
Kazuhiko Yamashita
MSMasao Saito
Masao Saito
This study intends to clarify the effect of a static magnetic field on cellular activities. It is concerned with the metabolic activity of mitochondria from the viewpoint of their energy level. As a preliminary examination, the time required to render the cells to the low‐energy state (G0/G1 phase of the cell cycle) and to reduce their energy level was examined by maintaining the cells in medium with low‐density fetal bovine serum. Then, we examined the effect of the magnetic field on mitochondrial energy activity from the viewpoint of cell metabolism estimated by the MTT assay. We also examined the cell respiration, expecting that the mitochondrial energy activity level would be reflected in the respiration. The magnetic field was kept at 100 mT, with 0 mT as the control. The results of the MTT assay indicated that the mitochondrial energy activity was enhanced by a factor of 1.5. We found that the cell respiration was increased by a factor of 1.3 on exposure to the magnetic field. The t‐test showed the difference to be statistically significant. It is thus concluded that mitochondrial energy activity is enhanced in the G0/G1 phase of the cell cycle by exposure to a magnetic field. On the other hand, we also found that the mitochondrial energy cycle period is little affected. © 2001 Scripta Technica, Electr Eng Jpn, 137(1): 36–41, 2001

1 January 2017 in Advanced Biomedical Engineering
Verified
Journal Article
Closed access
KYKazuhiko Yamashita
Kazuhiko Yamashita
EAEmi Anzai
Emi Anzai
TYTomoko Yamashita
Tomoko Yamashita
YOYuji Ohta
Yuji Ohta
MSMitsuru Sato
Mitsuru Sato
YOYuko Ohno
Yuko Ohno

13 November 2024 in Journal of Surgical Research
Verified
Journal Article
Open access
KKKaori Kusuda
Kaori Kusuda
KYKazuhiko Yamashita
Kazuhiko Yamashita
EMEmiko Morishita
Emiko Morishita
NINao Ishibashi
Nao Ishibashi
YSYoshito Shiraishi
Yoshito Shiraishi
HYHiromitsu Yamaguchi
Hiromitsu Yamaguchi
Introduction: To improve patient safety and reduce burden on healthcare professionals and institutions, the individual management of surgical instruments is essential. There are two methods for individual item management: radio-frequency identification (RFID) and barcoding. However, there has been no examination of efficiency regarding reading times. Therefore, this study aimed to compare the reading times of RFID-tagged and barcodeengraved surgical instruments and evaluate the influence of operator proficiency. Methods: The participants included 8 individuals and 41 surgical instruments from a varicose vein set. RFID tags and barcodes were attached to the surgical instruments. Five trials were conducted for each, and the reading times were measured. Results: The reading times for RFID-tagged surgical instruments in the skilled and unskilled groups were 64.0 f 9.0s and 79.4 f 17.0 s, respectively, whereas those for barcode-engraved surgical instruments were 190.4 f 28.1 s and 212.3 f 40.3 s, respectively. Barcodes took 3.0 and 2.7 times longer to read than RFID-tagged instruments for the skilled and unskilled groups, respectively. Additionally, skilled operators using barcodes required 2.4 times more time than unskilled operators using RFID. Even nonmedical individuals were able to achieve quick and accurate readings with RFID. The estimated labor hours per person were $24,146-$42,322 for RFID and $71,078-$110,898 for barcode scanning for a year (working 8 h/ d for 250 d). Conclusions: RFID-tagged surgical instruments impose a lighter workload and financial burden than barcode-engraved surgical instruments. RFID technology may also improve patient safety due to less dependency on operator proficiency. (c) 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

15 February 2024 in Medical Engineering & Physics
Verified
Journal Article
Open access
TYTomoko Yamashita
Tomoko Yamashita
KYKazuhiko Yamashita
Kazuhiko Yamashita
MSMitsuru Sato
Mitsuru Sato
SAShingo Ata
Shingo Ata
Frailty in older adults often leads to foot issues, increasing fall-related fracture risk. Mechanoreceptors, the pressure receptors in the foot sole, are pivotal for postural control. Foot problems can impair mechanoreceptor function, compromising balance. This study aimed to examine the effect of foot care on postural control in frail older adults. Forty-eight participants underwent a five-month monthly foot care intervention. Measurements were taken before and after this intervention. Participants stood for 45 s in a static, open-eyed position on a stabilometer. Center-of-pressure (CoP) analysis included total trajectory length, integrated triangle area, rectangular area, and range of motion in anterior-posterior and medio-lateral directions. Results indicated that foot care significantly increased toe ground contact area by 1.3 times and improved anterior-posterior motion control during static standing. Enhanced postural control resulted from improved skin condition due to foot care that intensified mechanoreceptor signal input and improved postural control output. These findings underscore the potential for reducing fracture risks in older adults through proactive foot care. The study highlights the vital role of foot care in enhancing postural control, with broader implications for aging population well-being and safety.