Bipedal Robot Running: Human-like Actuation Timing Using Fast and Slow Adaptations

We have been developing human-sized biped robots based on passive dynamic mechanisms. In human locomotion, the muscles activate at the same rate relative to the gait cycle during running. To achieve adaptive running for robots, such characteristics should be reproduced to yield the desired effect. In this study, we designed a central pattern generator (CPG) involving fast and slow adaptation to achieve human-like running using a simple spring-mass model and our developed bipedal robot, which is equipped with actuators that imitate the human musculoskeletal system. Our results demonstrate that fast and slow adaptations can reproduce human-like running with a constant rate of muscle firing relative to the gait cycle. Furthermore, the results suggest that the CPG contributes to the adjustment of the muscle activation timing in human running.Comment: 15 pages, 12 figures, submitted to Advanced Robotic

膵癌重粒子線治療前後のFDG-PET/CT変化

[Objective] FDG-PET/CT has been reported to be of prognostic value for pancreaic cancer. However, few previos studies have shown the relationsip between FDG-PET/CT metabolic parameters and the early response after carbon-ion radiotherapy (CIRT) and surgeryain patients with pancreatic cancer. The aim of this study is to assess the metabolic changes on F-18 FDG-PET/CT (FDG-PET/CT ) performed before and 3 months after CIRT in patients with locally advanced pancreatic cancer.[Materials and Methods] Nineteen locally advanced pancreatic cancer patients who had pre-CIRT chemotherapy followed by 55.2Gy/12Fractions CIRT were enrolled in this study. Patients received FDG-PET/CT before treatment (pre-CIRT PET/CT) and 3 months from the end of CIRT (3M-CIRT PET/CT)metabolic parameters such as SUVmax, Metabolic tumor volume (MTV), Total lesion glyclysis and SUVpeak were evaluated to assess the relationship with the early response of CIRT for the pancreatic cancer. Moreover, On 3M-CIRT PET/CT, metabolic response group of CMR or PMR was defined as responder, and another group of SMD or PMD was defined as non-responder. Then, PERCIRT were used for response evaluation based on SUV corrected for lean body mass (SUL and SULpeak).[Rsults] SUVmax pre- and 3M after CIRT were 4.32+/-1.50 and 2.94+/-0.83, respectively. MTV pre- and 3M after CIRT were 4.45+/-3.78 and 2.34+/-2.44, respectively. TLG pre- and 3M after CIRT were 17.39+/-17.39 and 6.89+/-8.33, respectively. SUVpeak pre- and 3M after CIRT were 3.94+/-1.39 and 2.64+/-0.96, respectively. Lof-rank t-test analysis for progression free survival revealed that patients who showed SUVpeak-reduction greater than 30% than that of pre-CIRT predicted early response of the therapy. The result of Kaplan-Meier analysis of PFS stratified using PERCIST showed a significant difference getween responder group and non-responder group (P<0.05, Lof-rand test).[Conclusion] The chanses of metabolic activity ana PERCIST criteria based of FDG-PET/CT during pre and 3 months after CIRT would be useful for prediction of progression-free survival after CIRT in patients with locally advanced pancreatic cancer.第77回日本医学放射線学会総

Assessment of PERCIST criteria of FDG-PET/CT to predict progression-free survival after carbon-ion radiotherapy in patients with locally advanced pancreas cancer.

[Objective] FDG-PET/CT has been reported to be of prognostic value for pancreaic cancer. However, few previos studies have shown the relationsip between FDG-PET/CT metabolic parameters and the early response after carbon-ion radiotherapy (CIRT) and surgeryain patients with pancreatic cancer. The aim of this study is to assess the metabolic changes on F-18 FDG-PET/CT (FDG-PET/CT ) performed before and 3 months after CIRT in patients with locally advanced pancreatic cancer.[Materials and Methods] Nineteen locally advanced pancreatic cancer patients who had pre-CIRT chemotherapy followed by 55.2Gy/12Fractions CIRT were enrolled in this study. Patients received FDG-PET/CT before treatment (pre-CIRT PET/CT) and 3 months from the end of CIRT (3M-CIRT PET/CT)metabolic parameters such as SUVmax, Metabolic tumor volume (MTV), Total lesion glyclysis and SUVpeak were evaluated to assess the relationship with the early response of CIRT for the pancreatic cancer. Moreover, On 3M-CIRT PET/CT, metabolic response group of CMR or PMR was defined as responder, and another group of SMD or PMD was defined as non-responder. Then, PERCIRT were used for response evaluation based on SUV corrected for lean body mass (SUL and SULpeak).[Rsults] SUVmax pre- and 3M after CIRT were 4.32+/-1.50 and 2.94+/-0.83, respectively. MTV pre- and 3M after CIRT were 4.45+/-3.78 and 2.34+/-2.44, respectively. TLG pre- and 3M after CIRT were 17.39+/-17.39 and 6.89+/-8.33, respectively. SUVpeak pre- and 3M after CIRT were 3.94+/-1.39 and 2.64+/-0.96, respectively. Lof-rank t-test analysis for progression free survival revealed that patients who showed SUVpeak-reduction greater than 30% than that of pre-CIRT predicted early response of the therapy. The result of Kaplan-Meier analysis of PFS stratified using PERCIST showed a significant difference getween responder group and non-responder group (P<0.05, Lof-rand test).[Conclusion] The chanses of metabolic activity ana PERCIST criteria based of FDG-PET/CT during pre and 3 months after CIRT would be useful for prediction of progression-free survival after CIRT in patients with locally advanced pancreatic cancer.SNMMI201