The objective of this study was to verify the usefulness of a “parallel link type human ankle rehabilitation assistive device” (PHARAD) that we developed for prevention of deep vein thrombosis (DVT). We evaluated the blood flow (BF)-promoting effect of passive and active (with and without load) ankle exercises performed using the PHARAD, by comparing BF before and after exercise. Ten healthy male adults were recruited. Each subject performed 3-minute passive, active (without load), and active loaded ankle exercise, as well as walking. The ankle exercise consisted of plantar flexion/dorsiflexion (P/D) and rotation motion. BF was measured at the medial head of the gastrocnemius muscle (MG) and the vastus medialis muscle (VM). BF was calculated from the rate of increase in total hemoglobin concentration during venous occlusion. During all the exercises, BF measured at both muscles increased significantly compared to resting level (p<0.05). In passive P/D, BFs in MG/VM increased to 154.5±66.2%/146.4±55.4% of the resting levels. In passive rotation motion, the corresponding BFs increased to 183.6±91.9%/144.3±63.0% of the resting levels. The BF-promoting effects (MG/VM) of passive P/D were 51.2%/105.7% of active (without load) exercise and 53.3%/56.4% of walking. In active loaded P/D, BFs at MG/VM increased to 239.2±71.1%/182.8±132.6% of the resting levels. In active loaded rotation motion, the corresponding BFs increased to 286.3±148.6%and 208.7±130.5% of the resting levels. The BF-promoting effects (MG/VM) of active loaded P/D were 131.3%/177.3% of active (without load) exercise and 182.2%/132.2% of walking. There were no significant differences in passive, active (without load) and active loaded exercises with respect to the BF-promoting effects of P/D and rotation motion. These results suggest the following:1) Passive and active loaded exercises using PHARAD significantly increase BF compared to the resting level. 2) Passive exercise has the potential to prevent DVT. 3) Active loaded exercise is more effective than walking in promoting BF. 4) P/D and rotation motion have the same level of BF-promoting effect. 4)does not suggest the superiority of PHARAD that can perform rotation exercise, but 1)-3)suggest the usefulness of PHARAD for DVT prevention.
Daily walking keeps our body healthy. However, it is difficult to continue walking as a daily habit. To promote the habit of daily walking, we focus on the effect of team work. We often achieve big goals with others by working as a team and assisting each other. In this paper, we propose a system that helps users work as a team in daily walking. Our system uses a smartphone and a web application to allow users to see not only his/her own activity but also his/her team members' activities. We expected that seeing the exercise data of team members would encourage an individual to exercise. We held a one-month field trial in Nagahama City as a walking event. A total of 457 participants (96 teams and 85 individuals) were enrolled in the trial. Each participant was asked to walk 40km within 10 days, which is equivalent to 10,000 steps a day. At the end of the trial, 87 out of 96 teams achieved this goal. Analysis of participants' records for teams consisting of 5 members showed a difference in walking distance of over 20km among team members in 80% of the teams. This finding indicates that even though not all members of a team walked the same distance, they achieved the team's goal by sharing target distances according to their capability. Web access records show that 85% of the team participants watched his/her team members' activity more than once every 2 days. Participants' responses to questionnaires showed that 73% of team participants used communication within team members to motivate themselves. Additionally, the number of people who walk everyday increased even three months after the trial. These results suggest that the team effect has the potential to motivate members to continue their exercising activities.
Antihypertensive treatments are inadequate for many hypertensive patients. In these patients, technologies for continuous and comprehensive analysis of the cardiovascular system based on non-invasive measurements of blood pressure, blood flow, and peripheral vascular resistance are desirable. Tonometry and Doppler methods are non-invasive and continuous sensing methods for blood pressure and blood flow, respectively. However, simultaneous measurements of pressure pulse wave by tonometry and blood flow by Doppler method on the same vessel or nearby vessels are difficult, because of the mechanical occlusion of the vessel by the tonometry sensor. This study examined the relationship between pulse pressure and blood flow at the hold-down pressure (HDP) for measuring pressure pulse wave at the radial artery. We quantified the influence on tonometry and blood flow based on the experimental data and determined the optimal HDP that caused no interference between tonometry and Doppler method. The results indicate that the detected pressure pulse wave represents the blood pressure under the optimal HDP, and that the proposed method is capable of sensing blood pressure and blood flow continuously. This proposed method for detecting unexpected fluctuations in blood pressure and its mechanism may contribute to the treatment of cardiovascular disease.
Surgery under endoscopic vision has advantages such as lower invasiveness, less bleeding, and less pain for patients, providing expanded vision for precise operation compared with open abdominal surgery. To improve preservation of normal tissue and flexible utilization of ultrasound imaging, water-filled laparoendoscopic surgery (WaFLES) has been actively researched. In WaFLES, the abdominal cavity is filled with saline instead of insufflated with carbon dioxide gas. The circulating irrigating solution maintains desirable moisture and temperature for organs as well as provides a clear endoscopic view. By buoyancy effect, the organs are floating and easy to move during surgery, but organs around the surgical field often affect the surgeon's view. We propose a novel surgical spacer for WaFLES based on reversible structural alteration between two- and three-dimensional shapes, which is designed to be inserted through a single small incision and expanded in the abdominal cavity independently. We designed and fabricated prototypes of the proposed spacer made of polyvinyl chloride and polyethylene terephthalate, and tested their structural strengths. The prototypes demonstrated the required strength to withstand the forces loaded from organs around the treated area under WaFLES conditions.