Regards to the therapy for end-stage failing heart, the heart transplantation is the only effective treatment but is still limited by donor shortage. Therefore, a novel strategy for myocardial regeneration are desired. Cell transplantation as a new approach to restore impaired heart still has several problems. Recently, we have developed cell sheet implantation to impaired heart. Therefore, we hypothesized that a tissue engineered contractile cardiomyocyte sheets may promise myocardial regeneration in the impaired myocardial injury.‹Experiment 1› Two weeks after Left anterior descending (LAD) ligation, two different treatments were conducted; 30 rats were divided into three groups; cardiomyocytes sheets implantation (T group, n=10), fibroblast sheets implantation (F group, n=10) and the control group with no treatment (C group, n=10). Cardiomyocyte sheets attached on the infarct myocardium in alignment and seemed to be homogeneous tissue in the myocardium. And immunohistochemical stain demonstrated neoangiogenesis and randomly oriented Connexin 43 in implanted cardiomyocyte sheets.‹Experiment 2› We constructed autologous myoblast sheets by the same method as cardiomyocyte sheets and implanted to the infarct myocardium. Myoblast sheets showed attachment to myocardium with angiogenesis. Systolic function was significantly higher in the myoblast sheet group. Histology revealed greater cellularity without scar formation and reduction of LV dilatation due to significant thickened wall. In conclusion, cardiomyocyte sheets integrated the impaired myocardium and improved cardiac performance. Thus, the contractile cardiomyocyte sheets may potentially regenerate the impaired myocardium.
In order to realize true regenerative medicine, diverse research fields should be integrated for the establishment of a collective research group with various disciplines. For example, less invasive cell sheet transplantation in clinical settings should be achieved by the utilization of computer-aided robotic surgery. Here, I summarize my personal view and inside stories on early development of cell sheet engineering and its clinical applications in regenerative medicine from my research experiences as well as philosophy inspired by scientific fiction movies.
The development of artificial blood had been proceeded through the development research of the artificial oxygen carrier: TRM-645 to substitute for the blood transfusion. We have developed the liposome encapsulated hemoglobin that have superior function for oxygen transport which was close to red blood cell as the biomimetics-technology of red blood cell. The function of oxygen transport was designed which the P50 value was controlled to 40-50 torr to use the inositol-hexaphosphate as an allosteric effector. The oxygen transporting efficiency of TRM-645 under respiration with 30-50% oxygen was superior to that of human red blood cells (hRBC). The development of the artificial oxygen carrier will be able to evolve to aim at the treatment for the stroke and the myocardial infarction as oxygen infusion liquid from the blood substitution in future. So, development of the function design will change from the blood substitution to the therapeutic purposes.
Though the Human Genome Project was completed, analyses of gene information will continue for many years especially in live cell analysis. To take observation for these research, various systems for examining living cells and DNA have developed. With these solutions, research in post genome science trends toward new approaches to research on new drugs, clinical analysis and diagnosis.
In this paper, we propose a method for generating virtual laparoscopic images for the aid of laparoscopic surgery. Since the field of view of a laparoscope is very limited, the load of a surgeon who performs laparoscopic surgery is quite large. It would be very useful to generate virtual laparoscopic images from pre-operative CT or MRI images. Since the abdominal wall is lifted during laparoscopic surgery, it is required to deform an original CT image for generating a virtual laparoscopic image. We extract the abdominal wall semi-automatically and model the extracted abdominal wall by using a node and spring model. The method lifts the abdominal wall by elastic deformation. A virtual laparoscopic image is obtained by reconstructing the CT image from the result of elastic deformation. We applied the proposed method to four abdominal X-ray CT images. Experimental results showed that the proposed method could generate virtual laparoscopic images and were very useful for pre-operative surgical planning and intra-operative surgical navigation.
This paper proposes the planning and navigation of a surgical robot to perform safe and effective operations using finite element analysis results based on physical models of the brain. The physical brain models were determined based on the results of physical property tests. Finite element analyses of virtual tension tests were carried out under the same conditions as the actual tension tests, and the results of the analysis coincided with those of the test. The finite element analyses of robotic brain surgery were carried out using a two-dimensional structure, which consisted of the proposed physical models. Assuming two types of robot models are used (the brain spatula and capsule type robot respectively), stress distribution in the brain, caused by each robot model, was simulated in the analyses. The preoperative planning was considered based on the analysis results, and the safe velocity of the robot's movement was estimated as well. The results of this research showed that organ modeling was necessary for preoperative planning in order to implement safe surgery.
For medical stereoscopic imaging, the usefulness of the presentation of depth information and the issues of picture quality and fatigue have been discussed. The aim of this study is to investigate the influence of binocular stereopsis on surgeon's fatigue by subjective and psychophysiological scores. 14 subjests were asked to perform three kinds of tasks-a pegboard, incision, and suturing-under the 2D and 3D conditions conducted for one hour in total. We evaluated the degree of fatigue by a questionnaire (Subjective Symptom Test of Fatigue) and by the critical flicker fusion frequency (CFF) test. In the flicker test, eyestrain due to the tasks was not observed under either 2D or 3D display conditions. Although subjective fatigues of muscles and eyes were significant, no difference was found depending on the display conditions. CFF did not show any evidence of fatigue caused by the binocular stereopsis.