Takeshi Ohdaira

Kyushu University, Hukuoka, Fukuoka, Japan

Are you Takeshi Ohdaira?

Claim your profile

Publications (28)41.74 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We know that experienced endoscopic surgeons, despite having extensive training, may make a rare but fatal mistake. Prof. Takeshi Ohdaira developed a device visualizing brain action potential to reflect the latent psychological instability of the surgeon. The Ohdaira system consists of three components: a real-time brain action potential measurement unit, a simulated abdominal cavity, and an intra-abdominal monitor. We conducted two psychological stress tests by using an artificial laparoscopic simulator and an animal model. There were five male subjects aged between 41 to 61 years. The psychological instability scores were considered to reflect, to some extent, the number of years of experience of the surgeon in medical care. However, very high inter-individual variability was noted. Furthermore, we discovered the following: 1) bleeding during simulated laparoscopic surgery-an episode generally considered to be psychological stress for the surgeon-did not form the greatest psychological stress; 2) the greatest psychological stress was elicited at the moment when the surgeon became faced with a setting in which his anatomical knowledge was lacking or a setting in which he presumed imminent bleeding; and 3) the excessively activated action potential of the brain possibly leads to a procedural error during surgery. A modified brain action potential measurement unit can reveal the latent psychological instability of surgeons that possibly leads to errors in surgical procedures.
    Surgical technology international 05/2015; 26:25-30.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aims: To investigate the utility of ozone nanobubble water (NBW3) for the treatment of Helicobacter pylori in the stomach, we tested the influence of pepsin concentrations and pH levels on the disinfective activity of NBW3, and the cytotoxicity of NBW3 against mammalian cells and mucosa. Methods: Different concentrations of pepsin were dissolved in NBW3, and the bactericidal activity was tested on H. pylori. NBW3 was adjusted to different pH levels (2.0-7.4) and the bactericidal activity on H. pylori was also tested. To examine the cytotoxicity of NBW3, AGS cells, human gastric epithelial cells, were treated with NBW3 and the viability of the cells was evaluated in vitro. Furthermore, NBW3 was administered to mice and gastric mucosal damage was evaluated by histology. Results: Pepsin reduced the disinfective activity of NBW3 on H. pylori in a pepsin concentration-dependent manner. NBW3 showed stable disinfective activity at all pH levels examined. Cytotoxicity of NBW3 against human gastric epithelial cells and gastric mucosa was not observed in our experimental setting. Conclusions: NBW3 can sustain its disinfective activity in wide range of pH levels and show no cytotoxicity on mammalian cells and tissue. Pepsin can inhibit NBW3 activity in a dose-dependent manner.
    Digestion 07/2014; 90(1):10-17. DOI:10.1159/000358286 · 2.10 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Current robotic systems have limitations for single-port surgery (SPS) because the instruments are large, the arms collide and the field of vision requires manual readjustment. We have developed an SPS robotic system that manipulates the vision field.Methods The master–slave system included a six degrees of freedom (DOFs) tool manipulator, an easy set-up mechanism, a flexible shaft drive with sufficient DOFs and a vertical arrangement for improved vision. The robot manipulates an endoscope within the body. After assembly, the system was tested in vitro and in vivo.ResultsIn vitro testing showed that the tool manipulators resected tissue precisely, with the range of motion required. In vivo testing indicated that an abdominal organ is accurately approached and diseased tissue removed by combined endoscopy and robotics.Conclusions Our robotics allowed the operator to adjust the vision field intuitively. The tool manipulator approached and resected diseased tissue precisely. Copyright © 2014 John Wiley & Sons, Ltd.
    International Journal of Medical Robotics and Computer Assisted Surgery 06/2014; 11(2). DOI:10.1002/rcs.1600 · 1.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Background: Metacognition is the knowledge about one's own methods of perceiving, remembering, thinking, and acting. This study determined the significance of metacognitive skills in laparoscopic surgery with the aim of applying the findings in a laparoscopic surgery training program. Material and methods: Eighteen medical students with no experience in laparoscopic surgery (novice group) and eight expert surgeons who had each performed >100 laparoscopic surgeries (expert group) were enrolled. The examinees in each group performed an evaluation task using a virtual reality simulator and answered questions about the task. Results: The longest performance times, longest path lengths, and most frequent tissue damage occurred at 135° in the novice group and at 180° in the expert group. The greatest recognition of task difficulties, impatience, and irritation occurred at 135° in the novice group and at 180° in the expert group. There were statistically significant correlation coefficients between the instrument path length and task difficulty (metacognition) at 135° (R = 0.74, p = 0.03) and 180° (R = 0.79, p = 0.02) in the expert group, but there were no significant correlations in the novice group. Conclusion: We elucidated the significance of metacognitive skills in laparoscopic surgery. A training program should include recognition feedback systems.
    Minimally invasive therapy & allied technologies: MITAT: official journal of the Society for Minimally Invasive Therapy 12/2013; 23(3). DOI:10.3109/13645706.2013.867273 · 1.27 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Background: Endoscopic surgery is currently a standard procedure in many countries. Furthermore, conventional four-port laparoscopic cholecystectomy is developing into a single-port procedure. However, in many developing countries, disposable medical products are expensive and adequate medical waste disposable facilities are absent. Advanced medical treatments such as laparoscopic or single-port surgeries are not readily available in many areas of developing countries, and there are often no other sterilization methods besides autoclaving. Moreover, existing reusable metallic ports are impractical and are thus not widely used. Material and methods: We developed a novel controllable, multidirectional single-port device that can be autoclaved, and with a wide working space, which was employed in five patients. Results: In all patients, laparoscopic cholecystectomy was accomplished without complications. Conclusion: Our device facilitates single-port surgery in areas of the world with limited sterilization methods and offers a novel alternative to conventional tools for creating a smaller incision, decrease postoperative pain, and improve cosmesis. This novel device can also lower the cost of medical treatment and offers a promising tool for major surgeries requiring a wide working space.
    Minimally invasive therapy & allied technologies: MITAT: official journal of the Society for Minimally Invasive Therapy 06/2013; 22(6). DOI:10.3109/13645706.2013.808229 · 1.27 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Introduction: Transrectal natural orifice translumenal endoscopic surgery (NOTES) requires a good endoluminal view and adequate intrarectal bacterial clearance in the working area. We developed a new occlusion balloon unit with an easily detachable inflation device, which allows the surgeon a clear working area distal to the balloon. Material and methods: The effectiveness of the sealing balloon and the extent of macroscopic and histopathological injury to the bowel wall at the site of balloon placement were examined in 12 pigs. Results: The mean time to place and inflate the balloon unit was 12.0 ± 3.5 min, effective air-tightness lasted for 21.0 ± 12.0 min. There was no leakage of dye (methylene blue) past the balloon when pressure was maintained >6.70 ± 0.08 kPa (6.62-6.78 kPa). After gut irrigation, good visibility was maintained in the working area for six hours, and adequate bacterial clearance was maintained for three hours. There were no macroscopic signs of intestinal wall damage at the site of balloon placement. Histopathological examination showed only patchy mucosal damage and submucosal thrombus at the site of balloon placement. Conclusion: This newly-developed occlusion balloon unit helps to establish good visibility and adequate bacterial clearance for endoluminal surgical procedures.
    Minimally invasive therapy & allied technologies: MITAT: official journal of the Society for Minimally Invasive Therapy 10/2012; 22(3). DOI:10.3109/13645706.2012.732080 · 1.27 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Radiofrequency (RF) ablation is increasingly used to treat cancer because it is minimally invasive. However, it is difficult for operators to control precisely the formation of coagulation zones because of the inadequacies of imaging modalities. To overcome this limitation, we previously proposed a model-based robotic ablation system that can create the required size and shape of coagulation zone based on the dimensions of the tumor. At the heart of such a robotic system is a precise temperature distribution simulator for RF ablation. In this article, we evaluated the simulation accuracy of two numerical simulation liver models, one using a constant thermal conductivity value and the other using temperature-dependent thermal conductivity values, compared with temperatures obtained using in vitro experiments. The liver model that reflected the temperature dependence of thermal conductivity did not result in a large increase of simulation accuracy compared with the temperature-independent model in the temperature range achieved during clinical RF ablation.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2012; 2012:5712-7. DOI:10.1109/EMBC.2012.6347292
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have developed a new generation device called rigid-flexible outer sheath with multi-piercing surgery (MPS) to solve the issues of tissue closure, triangulation, and platform stability in natural orifice transluminal endoscopic surgery (NOTES), and the problems of restricted visual field, organ damage, and removing a resected organ from body in needlescopic surgery (NS). The shape of the flexible outer sheath can be selectively locked by a novel pneumatic shapelocking mechanism. Major features include four directional flexion at the distal end, four working channels, and suction and water jet functions. The insertion part of the prototype is 330 mm long with a 25 mm maximum outer diameter. The outer sheath system has successfully preformed in vivo experiment using a swine on partial gastrectomy. The advanced outer sheath system has shown great promise for solving NOTES and NS issues.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In endoscopic surgery, limited views and lack of tactile sensation restrict the surgeon's abilities and cause stress to the surgeon. Therefore, an intra-operative navigation system is strongly recommended. We developed an augmented reality (AR) navigation system based on preoperative CT imaging. The purpose of this study is to evaluate the usefulness, feasibility, and accuracy of this system using laparoscopic splenectomy in children. Volume images were reconstructed by three-dimensional (3D) viewer application. We used an optical tracking system for registration between volume image and body surface markers. The AR visualization was superimposed preoperative 3D CT images onto captured laparoscopic live images. This system was applied to six cases of laparoscopic splenectomy in children. To evaluate registration accuracy, distances from the marker position to the volume data were calculated. The operator recognized the hidden vascular variation of the splenic artery and vein, accessory spleen, and pancreatic tail by overlaying an image onto a laparoscopic live image. The registration accuracy of six cases was 5.30 ± 0.08, 5.71 ± 1.70, 10.1 ± 0.60, 18.8 ± 3.56, 4.06 ± 1.71, and 7.05 ± 4.71. This navigation system provides real-time anatomical information, which cannot be otherwise visualized without navigation. The registration accuracy was acceptable in clinical operation.
    Pediatric Surgery International 12/2011; 28(4):341-6. DOI:10.1007/s00383-011-3034-x · 1.00 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Radiofrequency ablation is increasingly being used for liver cancer because it is a minimally invasive treatment method. However, it is difficult for the operators to precisely control the formation of coagulation zones because of the cooling effect of capillary vessels. To overcome this limitation, we have proposed a model-based robotic ablation system using a real-time numerical simulation to analyze temperature distributions in the target organ. This robot can determine the adequate amount of electric power supplied to the organ based on real-time temperature information reflecting the cooling effect provided by the simulator. The objective of this study was to develop a method to estimate the intraoperative rate of blood flow in the target organ to determine temperature distribution. In this paper, we propose a simulation-based method to estimate the rate of blood flow. We also performed an in vitro study to validate the proposed method by estimating the rate of blood flow in a hog liver. The experimental results revealed that the proposed method can be used to estimate the rate of blood flow in an organ.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2011; 2011:7441-5. DOI:10.1109/IEMBS.2011.6091745
  • [Show abstract] [Hide abstract]
    ABSTRACT: Recently, robotics systems are focused to assist in Single Port Endoscopic Surgery (SPS). However, the existing system required a manual operation of vision and viewpoint, hindering the surgical task. We proposed a surgical endoscopic robot for SPS with dynamic vision control, the endoscopic view being manipulated by a master controller. The prototype robot consists of a manipulator for vision control, and dual tool tissue manipulators (gripping: 5DOFs, cautery: 3DOFs) can be attached at the tip of sheath manipulator. In particular, this paper focuses on an in vivo experiment. We showed that vision control in the stomach and a cautery task by a cautery tool could be effectively achieved.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2011; 2011:7045-8. DOI:10.1109/IEMBS.2011.6091781
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have invented multi-piercing surgery (MPS) which could potentially solve the triangular formation loss and device clashing which occur in single-port surgery (SPS), as well as restricted visual field, organ damage by needle-type instruments, and impaired removal of a resected organ from the body which occur in needlescopic surgery (NS). MPS is natural orifice translumenal endoscopic surgery (NOTES)-assisted NS. We used 3-mm diameter robots as needle-type instruments for MPS to examine the possibility of local immune cell therapy and regenerative therapy using stem cells for pancreatic cancer. In MPS using two robots, the therapeutic cell suspension was injected into a target region of pancreas in two pigs. Both retention of a capsule of liquid cell suspension and invasive level were evaluated. Triangular formation could be ensured. The use of small-diameter robots allowed (1) the surgical separation of the pancreas and the retroperitoneum, and (2) the formation of the capsule containing the immune cell and stem cell suspension. The endoscope for NOTES provided a clear visual field and also assisted the removal of a resected organ from the body. The visual field of the endoscope could be oriented well by using an electromagnetic navigation system. MPS using small-diameter robots could potentially solve the issues inherent in SPS and NS and could allow minimally invasive local immune cell and stem cell therapy.
    Journal of Hepato-Biliary-Pancreatic Sciences 07/2011; 18(4):499-505. DOI:10.1007/s00534-011-0384-7 · 2.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Single port access (SPA) surgery is a laparoscopic procedure using only one transumbilical-placed port. Natural orifice transluminal endoscopic surgery (NOTES) offers the possibility of surgery without visible scars. To address the access and stability problems in SPA and NOTES, we developed a device called rigid-flexible outer sheath. This sheath can be switched between flexible and rigid modes by a novel pneumatic shapelocking mechanism, and it has a double curvature structure that enables it to flex in four directions at the distal end and three directions on the rigid-flexible shaft. The insertion part of the prototype is 300 mm long with a 20 mm outer diameter, and the part is equipped with four working channels. In vivo experiments using a swine show that the outer sheath has high potential for solving access and stability problems. We expect that the outer sheath will be useful for SPA and NOTES.
  • Takeshi Ohdaira · Yoshikazu Yasuda · Makoto Hashizume ·
    [Show abstract] [Hide abstract]
    ABSTRACT: In natural orifice transluminal endoscopic surgery (NOTES) using a single endoscope, the visual field moves unstably and a wide blind space is formed. We used wireless two wireless CCD cameras (270,000 and 380,000 pixels) placed on the abdominal wall of pigs and a conventional endoscope (410,000 pixels) at the same time to assess whether it was possible to observe the entire process of sigmoidectomy by NOTES. The titanium dioxide-coated lens was used as an antifogging apparatus. To control the CCD image frames, a magnetic body was affixed to the back of the CCD camera unit. To select a suitable visual-transmitter, three frequency bands were assessed: 0.07 GHz, 1.2 GHz, and 2.4 GHz. The cameras showed good performance for monitoring all procedures of the sigmoidectomy. The magnetic force most suitable to control the cameras was found to be 360 mT, and the best transmission frequency was 1.2 GHz. The battery could be used for up to 4 hours with intermittent use. The issue of lens fogging could be resolved by a water supply into the anal canal and a more than 12-hour ultraviolet irradiation. We verified that the CCD camera with the titanium dioxide-coated lens may be useful as the second eye in NOTES.
    Surgical technology international 01/2010; 19:38-46.
  • Takeshi Ohdaira · Kazuhiro Endo · Nozomi Abe · Yoshikazu Yasuda ·
    [Show abstract] [Hide abstract]
    ABSTRACT: In natural orifice transluminal endoscopic surgery (NOTES), the endoscope has the disadvantages of an unstable visual field and wide blind space. We developed a compact charge-coupled device (CCD) camera unit that can be transgastrointestinally placed in the abdominal cavity. The requisites for a wireless CCD camera unit for use in NOTES have been cited as: monitoring performance, fixation to the abdominal wall, attitude control, and antifogging functionality. Models to meet these requisites were prepared to assess their performance. The monitor had a CCD with dimensions of 7 x 7 x 7 mm and resolution of 410,000 pixels. The unit had a structure that allowed its attachment to the endoscope apex when placed to the abdominal wall. The abdominal wall fixation unit was equipped with a pantograph-type needle structure that was easily activated and retained by changing the polarity of an electromagnetic force. The pantograph-type needle head was designed to rotate by 360 degrees as an attitude-control mechanism, and both the pantograph and attitude-control mechanisms enabled attitude control in horizontal and vertical directions by a magnetic force applied from outside the body. Fogging was prevented by a vibration mechanism that physically cleaned the CCD lens surface and by titanium dioxide coating of the lens surface. The CCD camera unit was confirmed to have sufficient performance as an auxiliary monitor for endoscopy in terms of visual field and resolution. The pantograph-type needle structure successfully completed fixation of the CCD camera unit to the abdominal wall. Unit attitude was easily controlled, and fogging could be addressed by water supply before insertion of the CCD camera unit into the peritoneal cavity. The wireless CCD camera unit was verified to function as an effective second eye in NOTES by using the described mechanisms and antifogging coating.
    Surgical Endoscopy 07/2009; 24(1):198-209. DOI:10.1007/s00464-009-0554-8 · 3.26 Impact Factor
  • Takeshi Ohdaira · Kazuhiro Endo · Nozomi Abe · Yoshikazu Yasuda ·
    [Show abstract] [Hide abstract]
    ABSTRACT: We tried to determine whether the customization of an X-TRACT Tissue Morcellator could avoid the laceration-induced distension of surgical incisions/openings when transintestinally removing resected liver tissue from the body, when the greatest dimension of the tissue exceeded the dimension of the opening. Pigs were used to examine changes in the caliber and shape of surgical incisions made with a conventional hook knife and insulation-tipped diathermic (IT) knife for electrodissection in endoscopy, and to examine changes in circular incision made with a customized X-TRACT Tissue Morcellator. The ENDO CATCH II device was used to remove tissue. Laceration occurred in the "roundness-lost portion" of the surgical incisions made with the hook knife, thus confirming the greatest dimension of the distended incisions and the occurrence of an irregular laceration. In the circular incision that were made with the customized X-TRACT Tissue Morcellator, by contrast, the removal of resected liver tissue whose greatest dimension was fivefold greater than that of the surgical openings did not increase the caliber of the openings. The shape of the openings remained round, and no laceration was observed. The use of the customized X-TRACT Tissue Morcellator with an electrifiable round cutter allowed the performance of transintestinal hepatectomy and the removal of a solid organ through surgical openings that had been made in the gastrointestinal wall.
    Journal of Hepato-Biliary-Pancreatic Surgery 05/2009; 16(3):274-82. DOI:10.1007/s00534-009-0084-8 · 1.60 Impact Factor
  • Shigeto Ogura · Takeshi Ohdaira · Yasuo Hozumi · Yawara Omoto · Hideo Nagai ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Previous reports have indicated that small breast cancers without lymph node metastasis present a favorable prognosis. However, 10-20% of patients with T1 N0 invasive ductal carcinoma experience recurrence and have a poor prognosis. The objective of this study was to examine whether certain metastasis-related factors are prognostic of cancer recurrence in such patients at risk for relapse. Nineteen patients with the carcinoma who had recurrence 1-15 years after margin-free resection were examined. The control group consisted of 20 patients with pT1 pN0 invasive ductal carcinoma who had no recurrence for > or =10 years after radical surgery. The two groups were compared with respect to clinical profiles, conventional neoplastic features, and immunohistochemical expressions of 16 metastasis-related factors. No significant difference was found between the two groups in clinical profiles and conventional neoplastic features. However, six factors (MMP-2, MT1-MMP, T1MP-2, VEGF, cMET, and PCNA) were significantly expressed in the recurrence group against the control group. MMP-9 was significantly less expressed in the recurrence group. Of these factors, MMP-2, MT1-MMP, and VEGF showed the highest adjusted odds ratios. MMP family and growth factors may be promising predictors of recurrence risk of early stage breast cancer.
    Journal of Surgical Oncology 07/2007; 96(1):46-53. DOI:10.1002/jso.20805 · 3.24 Impact Factor
  • T Ohdaira · H Nagai ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Intraoperative tumor localization often is difficult during laparoscopic surgery for early-stage upper gastrointestinal tumors. This study enrolled 15 patients undergoing laparoscopic gastrectomy. A magnetic marking clip-detecting system was used to apply a marking clip to the tumor site during preoperative gastroscopy, and to detect a marking magnetic body. In a basic ex vivo study, the mean permeance rate on the gastric wall serosal surface was 0.97 +/- 0.01. Magnetic flux densities required for exploration were 52.6 mT on the gastric wall serosal surface and 312.4 mT 10 mm away from the surface. In a clinical study, the mean distance between the detected tumor site and the clip along the longitudinal axis was 8.3 +/- 3.2 mm. The mean detection time was 5.7 +/- 2.3 min. The magnetic marking clip-detecting system may be useful for tumor site detection during laparoscopic gastrectomy.
    Surgical Endoscopy 06/2007; 21(5):810-5. DOI:10.1007/s00464-006-9037-3 · 3.26 Impact Factor
  • T Ohdaira · Hideo Nagai ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Using a conventional Doppler probe, it is difficult to identify blood vessels precisely in lymph node dissection during laparoscopic surgery. For 26 patients undergoing laparoscopic colectomy and 26 patients undergoing laparoscopic subtotal gastrectomy, we used conventional and vertical scanning Doppler probes to compare their ability to identify invisible blood vessels through differences in power output voltage. The vertical scanning Doppler probe was 100% successful in identifying the target blood vessels regardless of the patient's body mass index (BMI), and also was superior to the conventional Doppler probe in detection sensitivity. The vertical scanning Doppler probe was useful for image training of recently qualified surgeons through real-time monitoring of the probe position and response on the monitor. Furthermore, findings showed that the vertical scanning Doppler probe was applicable to lymph node dissection as a forceps for laparoscopic usage. The vertical scanning Doppler could identify the target blood vessels regardless of the patient's BMI. It was verified to be useful as a surgical assistive device apart from being a sensor and may serve in the education of recently qualified surgeons.
    Surgical Endoscopy 06/2007; 21(5):782-4. DOI:10.1007/s00464-006-9094-7 · 3.26 Impact Factor
  • T Ohdaira · H Nagai · S Kayano · H Kazuhito ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Lens fogging during laparoscopic surgery extensively deteriorates operative field visibility and may provoke serious complications. A simulation model study was conducted using a conventional laparoscope, a conventional laparoscope plus heating (100 degrees C, 10 s), a conventional laparoscope plus surfactant, and a conventional laparoscope plus both a titanium dioxide (TiO2)-coated glass (with > or = 15 h of preoperative ultraviolet irradiation) and a water supply. For each, the time from laparoscope insertion into the peritoneal cavity to fogging-induced interruption of surgery was measured. The TiO2-coated glass had unique verified properties of exerting antifogging effects on the oil film after 15 or more hours of previous ultraviolet irradiation, and of inversely accelerating fogging after less than 15 h of previous ultraviolet irradiation. The clinical study showed later fogging with the TiO2-coated glass model, which successfully completed surgery without retraction of the laparoscope from the peritoneal cavity, as compared with the other models. An antifogging device using superhydrophilic TiO2-coated glass was very effective in preventing fogging during laparoscopic surgery.
    Surgical Endoscopy 02/2007; 21(2):333-8. DOI:10.1007/s00464-006-0795-8 · 3.26 Impact Factor

Publication Stats

184 Citations
41.74 Total Impact Points


  • 2010-2015
    • Kyushu University
      • Department of Advanced Medical Initiatives
      Hukuoka, Fukuoka, Japan
  • 2014
    • Kobe University
      Kōbe, Hyōgo, Japan
  • 2011
    • Waseda University
      • Graduate School of Science and Engineering
      Tokyo, Tokyo-to, Japan
  • 1999-2009
    • Jichi Medical University
      • • Division of General Surgery
      • • Department of Surgery
      Totigi, Tochigi, Japan