Fractal Dynamics in a Whole-Body Dynamic Balance Sport, Slacklining: A Comparison of Novices and Experts.

The present study investigated whether fractal dynamics can be observed during single-leg standing on a slackline. We also examined whether the temporal structure differs with skill level. To address these questions, we compared single-leg standing performance between novices (N=5) and experts (N=5) in terms of fractal dynamics in both ankles (i.e., stance and swing legs), center of mass, and head acceleration time series using detrended fluctuation analysis. Participants were required to perform single-leg standing on a slackline. To collect motion data while slacklining, we used a three-dimensional motion capture system and obtained time-series data on the position. We conducted detrended fluctuation analysis on the original acceleration time series and random shuffled time series to examine the fractal dynamics in each body part's fluctuation. Results suggest that experts showed persistent temporal structure in the swinging leg, center of mass, and head fluctuations in the horizontal direction, while that of novices did not differ from random fluctuations. These findings revealed that experts performing a single-leg standing task on a slackline show fractal dynamics. This might reflect their flexible or adaptive exploratory behavior in the performer-environment system and contribute to the dynamic stability of whole-body dynamic balancing.

Walking through a narrow opening improves collision avoidance behavior in a patient with stroke and unilateral spatial neglect: an ABA single-case design.

We investigated the effect of a 3-week intervention-wherein a patient with unilateral spatial neglect walks through a narrow opening while entering from the contralesional side-to improve walking ability or ADL. A 66-year-old man was diagnosed with right parietal subcortical hemorrhage. We used an ABA single-case design; period B was set as the intervention. The intervention improved the continuous walking distance and balance ability and decreased the number of collisions when walking through the narrow opening; however, it exerted minimal effect on ADL. Thus, the intervention may effectively improve continuous physical or spatial attention behavior, regardless of ADL improvement.

The effect of a haptic biofeedback system on postural control in patients with stroke: An experimental pilot study.

BACKGROUND: Impaired balance in patients with hemiparesis caused by stroke is frequently related to deficits in the central integration of afferent inputs, and traditional rehabilitation reinforces excessive visual reliance by focusing on visual compensation. OBJECTIVE: The present study investigated whether a balance task involving a haptic biofeedback (BF) system, which provided supplementary vibrotactile sensory cues associated with center-of-foot-pressure displacement, improved postural control in patients with stroke. METHODS: Seventeen stroke patients were assigned to two groups: the Vibrotactile BF and Control groups. During the balance task (i.e., standing on a foam mat), participants in the Vibrotactile BF group tried to stabilize their postural sway while wearing the BF system around the pelvic girdle. In the Control group, participants performed an identical postural task without the BF system. RESULTS: Pre- and post-test measurements of postural control using a force plate revealed that the stability of bipedal posture in the Vibrotactile BF group was markedly improved compared with that in the Control group. CONCLUSIONS: A balance task involving a vibrotactile BF system improved postural stability in patients with stroke immediately. This confirms the potential of a haptic-based BF system for balance training, both in routine clinical practice and in everyday life.

[NATURAL ORIFICE TRANSLUMENAL ENDOSCOPIC SURGERY].

The clinical application of natural orifice translumenal endoscopic surgery (NOTES) began in 2007, and several thousand patients worldwide have undergone the technique. In this review, we summarize and highlight the current status and future directions of NOTES. The most common procedures are cholecystectomy and appendectomy, mainly performed as hybrid NOTES through the transvaginal route. In addition, direct-target NOTES such as per oral endoscopic myotomy (POEM) or transanal total mesorectal excision has spread rapidly, because it allows access to the operative field without injuring healthy visceral organs. In Japan, a clinical registration system was established, and clinical applications are carried out safely. NOTES performed in Japan is characterized by procedures requiring extensive techniques of endoscopic treatment such as endoscopic full-thickness resection, POEM, and the submucosal tunnel method. It will be necessary to develop instruments and determine social needs to achieve pure NOTES. It will also be necessary to determine the significance of reducing surgical wounds on the body surface. Although much work is still needed to refine the techniques for NOTES, it appears to be developing as a new minimally invasive form of surgical and endoscopic treatment.

Gastric endoscopic submucosal dissection under steady pressure automatically controlled endoscopy (SPACE); a multicenter randomized preclinical trial.

BACKGROUND: Steady pressure automatically controlled endoscopy (SPACE) is a new modality that eliminates on-demand insufflation but enables automatic insufflation in the gastrointestinal tract. Though its use in porcine esophageal ESD was reported to be promising, its applicability and potential effectiveness to gastric procedures have not been evaluated. OBJECTIVE: The aims were (1) to evaluate feasibility and safety of SPACE in the stomach, and (2) to assess its potential advantages over conventional endoscopy in preventing "blind insufflation"-related complications. DESIGN: A multicenter randomized preclinical animal study. SETTING: Laboratories at three universities. INTERVENTIONS: Experiment 1: Gastric ESD was attempted in the swine (n = 17), under either SPACE or manual insufflation. Experiment 2: Gastroscopy was performed for 10 min in the perforated stomach (n = 10) under either SPACE or manual insufflation. MAIN OUTCOME MEASUREMENTS: Experiment 1: ESD time, energy device activation time, number of forceps exchanges, specimen size, en block resection rate, vital signs and any intraoperative adverse events. Experiment 2: Intra-gastric and intra-abdominal pressures, vital signs, and any adverse events. RESULTS: Experiment 1: Gastric ESD was completed in all animals. ESD time tended to be shorter in SPACE than in the control, though the difference was not significant (p = 0.18). Experiment 2: Although both intra-gastric and intra-abdominal pressures remained within preset values in SPACE, they showed excessive elevation in control. LIMITATIONS: An animal study with small sample size. CONCLUSIONS: SPACE is feasible and safe for complicated and lengthy procedures such as gastric ESD, and is potentially effective in preventing serious consequences related to excessive blind insufflation.

Incidence and predictors of adenocarcinoma following endoscopic ablation of Barrett's esophagus.

BACKGROUND: The rate and risk factors of recurrent or metachronous adenocarcinoma following endoscopic ablation therapy in patients with Barrett's esophagus (BE) have not been specifically reported. AIM: The aim of this study was to determine the incidence and predictors of adenocarcinoma after ablation therapy for BE high-grade dysplasia (HGD) or intramucosal carcinoma (IMC). METHODS: This is a single center, retrospective review of prospectively collected data on consecutive cases of endoscopic ablation for BE. A total of 223 patients with BE (HGD or IMC) were treated by ablation between 1996 and 2011. Primary outcome measures were recurrence and new development of adenocarcinoma after ablation. Recurrence was defined as the presence of adenocarcinoma following the absence of adenocarcinoma in biopsy samples from two consecutive surveillance endoscopies. Logistic regression analysis was performed to assess predictors of adenocarcinoma after ablation. RESULTS: One hundred and eighty-three patients were included in the final analysis, and 40 patients were excluded: 22 for palliative ablation, eight lost to follow-up, five for residual carcinoma and five for postoperative state. Median follow-up was 39 months. Recurrence or new development of adenocarcinoma was found in 20 patients (11 %) and the median time to recurrence/development of adenocarcinoma was 11.5 months. Independent predictors of recurrent or metachronous adenocarcinoma were hiatal hernia size ≥ 4 cm (odds ratio 3.649, P = 0.0233) and histology (HGD/adenocarcinoma) after first ablation (odds ratio 4.141, P = 0.0065). CONCLUSIONS: Adenocarcinoma after endoscopic therapy for HGD or IMC in BE is associated with large hiatal hernia and histology status after initial ablation therapy.

Evaluation of 0.6% sodium alginate as a submucosal injection material in endoscopic submucosal dissection for early gastric cancer.

BACKGROUND AND AIM: We have focused on sodium alginate (SA) solution as a potential submucosal injection material for endoscopic submucosal dissection (ESD). A previous SA solution had high viscosity and problems such as difficult handling. After its properties were adjusted, SA solution was examined in vitro and its clinical safety was evaluated. METHODS: With 0.4% sodium hyaluronate (SH) solution as a control, catheter injectability and mucosa-elevating capacity of 0.3-0.8% SA solutions were evaluated. Next, 0.6% SA solution was used for ESD in 10 patients with early gastric cancer in a prospective clinical study. RESULTS: Compared with 0.4% SH solution, 0.6% SA solution exhibited no significant difference in catheter injectability but significant superiority in mucosa-elevating capacity. In the clinical study, no adverse events were observed in any patient. CONCLUSION: The safety of 0.6% SA solution as a submucosal injection material was confirmed and it is suggested that its efficacy should be investigated in a larger number of cases.

Ectopic pancreatic adenocarcinoma in Meckel's diverticulum: a case report.

BACKGROUND: Malignant neoplasms arising from Meckel's diverticulum are rare and an adenocarcinoma in Meckel's diverticulum originating from ectopic pancreatic tissue is even rarer. Herein, we report a patient with an ectopic pancreatic adenocarcinoma in Meckel's diverticulum who was successfully treated with surgery and chemotherapy. CASE PRESENTATION: A woman in her sixties presented to another hospital with abdominal pain. Plain computed tomography suggested an abdominal tumor and she was referred to our hospital. Enhanced computed tomography revealed a 23-mm low-density tumor in the abdominal cavity. Surgery was performed with a tentative diagnosis of a mesenteric tumor, such as a gastrointestinal stromal tumor, schwannoma, or lymphoma. First, we inspected the peritoneal cavity with a laparoscope. This revealed numerous nodules in the small bowel mesentery, suggesting peritoneal dissemination. A 20-mm-diameter white tumor was found in the small intestine and diagnosed as a small intestinal cancer. The small intestine was partially resected laparoscopically through a small skin incision. The patient's postoperative course was uneventful, and she was discharged on postoperative day 9. Pathological examination revealed well-differentiated adenocarcinoma in the small intestine. The tumor had developed from a sac-like portion protruding toward the serosal side and had a glandular structure lined with flattened atypical cells. Neither pancreatic acinar cells nor islets of Langerhans were evident, suggesting a Heinrich type 3 ectopic pancreas. The final diagnosis was an adenocarcinoma originating from an ectopic pancreas in Meckel's diverticulum. After a smooth recovery, the patient commenced chemotherapy for pancreatic cancer. CONCLUSIONS: We present a very rare case of ectopic pancreatic carcinoma in Meckel's diverticulum.

Transrectal peritoneal access with the submucosal tunnel technique in NOTES: a porcine survival study.

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) procedures have been performed via transgastric, transvaginal, or transcolonic approaches. However, the transcolonic approach has potential disadvantages including intraperitoneal infection. To avoid such disadvantages, we applied the submucosal tunnel technique to transrectal peritoneal access in this study. Study aims are to clarify the technical feasibility of a submucosal tunnel method for transrectal abdominal access and to assess the healing process of the submucosal tunnel histopathologically. METHODS: The study comprised six female pigs. The following procedures were performed: (1) The mucosa was cut after injection of sodium hyaluronate into the submucosa at the upper rectum. (2) Submucosal tunneling was performed by endoscopic submucosal dissection technique. (3) A small incision was made at the end of the tunnel. (4) After transrectal peritoneoscopy, the mucosal incision site was closed with endoclips. RESULTS: Transrectal peritoneoscopy was successfully performed in all pigs. Necropsy revealed no findings of peritonitis. Histopathologic examination showed good healing of the submucosal tunnel. The wound healing process of the submucosal tunnel on postoperative day 7 was mainly in the inflammatory phase at the mucosal incision site, the proliferative phase at the submucosal tract, and the proliferative/remodeling phase at the seromuscular incision site. CONCLUSIONS: The submucosal tunnel technique appears to be useful and safe for transrectal peritoneal access because healing at the seromuscular incision site proceeded rapidly.

[Natural orifice translumenal endoscopic surgery: historical and future perspectives].

Natural orifice translumenal endoscopic surgery (NOTES) has gained much attention worldwide since the first report of transgastric peritoneoscopy in a porcine model in 2004. In this review, we summarize and highlight the current status and future directions of NOTES. Thousands of human NOTES procedures have been performed. The most common procedures are cholecystectomy and appendectomy, mainly performed through transvaginal access in a hybrid fashion with laparoscopic assistance, and the general complication rate is acceptable. Although much work is still needed to refine the techniques for NOTES, the development of NOTES has the potential to create a paradigm shift in minimally invasive surgery.

Impact of Joint Fixation on Postural Dynamics during Single-Leg Stance.

We investigated the relationship between the mechanical degrees of freedom (DoF) and its postural dynamics. The joint DoF was fixed to constrain the mechanical DoF. Nine participants were required to perform a single-leg stance task. The center of pressure trajectory data was analyzed. Ankle fixation induced a larger amount of variability in the anteroposterior direction, and less dimensionality and complexity in the mediolateral direction. These results suggest that the ankle joint fixation caused limited postural sway in the mediolateral direction; therefore, functional DoF and complexity decreased. In contrast, it increased the amount of postural sway variability in the anteroposterior direction. Our findings imply a direct relationship between the mechanical DoF of the human movement system and its postural dynamics.

Neurorehabilitation Method for Preventing the Collapse of Internal Model: Verification of Unconscious Motor Change Caused by Implicit Error Involved in Multimodal Sensory FBs(Feedbacks).

It remains challenging for patients with stroke to regain the proper gait they had before stroke onset. In this study, one of the significant reasons for the problem is assumed to be the collapse of patients' internal model. Therefore, this study aimed to propose a method for lower-limb rehabilitation in the acute phase to prevent the collapse of the internal model and simultaneously promote voluntariness.To verify the effect of the proposed method and determine the optimal FB conditions, a supine pseudo-walking system has been developed providing multimodal sensory FBs, including somatosensory FB (walking on the walking robot), load transfer FB (plantar vibration provided by the robot), and visual FB (walking scene shown in virtual reality).First, the implicit error range of each sensory FB that was unable to recognize was investigated according to Weber's law. Subsequently, 12 participants were asked to perform 12 steps of walking exercise in the system to evaluate the unconscious motor-changing effect due to different/multimodal FBs. Errors were presented at the 7th step in either three FBs in the ratio determined or their combinations (two or three types of FBs simultaneously changing).Second, to examine whether the effect can last and influence the motion after the training, a pre-post comparison test was performed with the training in the middle, wherein implicit errors were presented in the three kinds of FBs.The results show that presenting implicit error can cause motor change, and multiple types of FBs may have a better effect. The statistical data of 12 participants of the pre-post comparison test show that the average integrated electromyogram in the post-test appears significantly larger than that in the pre-test. The result indicates that the motor-changing effect of the proposed method has a subsequent influence on motion and shows the possibility of the future application of the proposed method to the rehabilitation field.

Unilateral spatial neglect affected by right-sided stimuli in a three-dimensional virtual environment: A preliminary proof-of-concept study.

Unilateral spatial neglect (USN) is defined as the inability to attend and see on one side, which seriously interferes with daily life. Clinically, patients with left USN commonly demonstrate a striking immediate capture of attention from ipsilesional, right-sided items as soon as a visual scene unfolds (i.e., magnetic attraction [MA]). Therefore, this preliminary study utilized a three-dimensional (3D) virtual environment to evaluate the effects of eliminating stimuli in the rightward space and directing attention to the left on neglect symptoms. METHODS: Seven patients with USN participated in this study, and two types of visual stimuli were created: the numbers and objects in the 3D virtual environment. To eliminate the visual stimuli on the right side, a moving slit was introduced in the virtual environment. During the experiment, patients were required to orally identify each object and number both in moving and nonmoving slit conditions. RESULTS: A statistical comparison of scores with and without the moving slit in the 3D virtual space indicated significant changes in the object stimuli condition; however, no statistically significant difference was observed in the number stimuli condition. CONCLUSIONS: Masking the right side within the 3D virtual space increased the number of objects that can be recognized on the left side by patients with USN. The results may allow interventions in a virtual reality environment that closely resembles the patient's real-life space.Clinical Relevance-Magnetic attraction is a symptom seen in patients in clinical practice, but there is no method of rehabilitation. The proposed moving slit method is expected to be effective because it enables attention guidance in a three-dimensional space.

Safety and efficacy of the submucosal tunnel without mucosal closure for the transgastric approach in a porcine survival model.

INTRODUCTION: Usefulness of submucosal tunneling for transgastric approach with clip closure of the mucosal incision in natural orifice translumenal endoscopic surgery (NOTES) has been described. Although the narrow longitudinal submucosal tunnel itself is considered good for wound approximation and healing, no reports have evaluated the sealing effect in this technique. This study was aimed at evaluating the technical feasibility of a submucosal tunnel technique for transgastric peritoneal access without mucosal closure. METHODS: Transgastric peritoneoscopy using submucosal tunneling with endoscopic submucosal dissection without mucosal closure was performed on six 40- to 45-kg female pigs. Measures included (a) evaluation of technical feasibility, (b) clinical monitoring for 7 days, (c) necropsy findings, and (d) pathological examination. RESULTS: NOTES transgastric peritoneoscopy was successfully performed in all pigs, and all recovered well clinically. Necropsy findings revealed no peritonitis, confirming completeness of gastric closure in 5 of the 6 pigs. One pig in which the submucosal layer of the tunnel was injured during dissection from the muscular layer showed local peritonitis. Pathological examination at the submucosal site tunnel showed wound healing with focal transmural fibrosis and inflammatory cell infiltration in 5 pigs, whereas the pig with peritonitis had a large mucosal defect with necrotic tissue, abscess formation, and focal transmural fibrosis. CONCLUSIONS: The submucosal tunnel technique without mucosal closure is safe and effective for transgastric peritoneal access and subsequent closure, when the endoscopists' learning curve is accomplished and the submucosal tunnel is produced without damaging of mucosa. It is necessary to use devices such as mucosal clips or tissue anchors in order to achieve adequate healing of mucosal defect.

Development of a vibrotactile cueing device that implicitly increases walking speed during gait training in stroke patients: an observational case series study.

One of the main sequelae of stroke is difficulty walking, which is characterised by decreased walking speed and asymmetrical walking patterns. Physical therapists often rely on explicit motor learning strategies, i.e., providing mainly verbal instructions for how movements should be performed. However, the voluntary movement induced by explicit instruction may lead to associated unintended muscle contractions or higher cognitive demand, which could be detrimental. We introduce a vibrotactile cueing device that implicitly improves walking speed. The stroke patient walks while alternating vibrational cues are given to the left and right sides of their waist. At each specified step, cueing frequency increases in the cueing group without the patient's awareness. The four patients in the cueing group did not notice the increase in walking speed during training; however, we observed an improvement in walking speed and cadence in patients using the proposed cueing system, which was maintained during the posttest phase. Additionally, patients using the cueing system were able to suppress excessive compensatory movements during training compared with patients who did not use the system. This case series study indicates that the proposed system for gait rehabilitation of stroke patients can enable an increase in walking speed without excessive effort.

The influence of a vibrotactile biofeedback system on postural dynamics during single-leg standing in healthy older adults.

The effectiveness of sensory substitution technology, such as haptic-based vibrotactile biofeedback (VBF), has been verified for balance training and rehabilitation. However, whether VBF training changes postural dynamics in older people remains unknown. This study investigated the influence of VBF training on postural dynamics during single-leg standing in older adults, using detrended fluctuation analysis (DFA). Twenty older adults participated in this study. Measurement of postural sway comprised three phases: first measurement session as a baseline test, postural training (day 1), and second measurement session (day 2). The BF group received BF training during the balance training session, while the control group practiced single-leg stance without BF. The center of pressure (CoP) trajectory was recorded in the first measurement session (pre) and second measurement session (post) at 50 Hz. DFA revealed the presence of two linear scaling regions in the CoP, indicating the presence of fast- and slow-scale fluctuations. For the BF group, slow-scale postural dynamics revealed more anti-persistent behavior after training in the anterior-posterior direction. However, the control group showed a change toward more random dynamics after training. These different influences suggest that the BF system might improve error correction strategies during single-leg standing for older adults, while single-leg standing training without the BF system might cause the loss of controllability in single-leg standing. Further, the results of the DFA are discussed in the context of balance training using VBF.

Quantification of Unilateral Spatial Neglect Symptoms Based on Identification of Exploratory Ability.

Unilateral spatial neglect (USN) is the failure to report, respond, or orient to novel or meaningful stimuli presented on the side opposite a brain lesion. In our previous study, we reported that the ability of patients with USN to perform when the neck was fixed (called cognitive ability) was different from that when the neck was not fixed (called exploratory ability). However, the exploratory ability index has not been clarified, and cognitive and exploratory abilities have not been quantified. Thus, in this study, we identified neck movement as an exploratory ability index for patients with USN. Furthermore, we proposed equations to quantify cognitive and exploratory abilities and suggested that these equations can be used to understand patients' neglect symptoms in more detail. These findings revealed that the two evaluations of cognitive and exploratory abilities are crucial in USN evaluation and are key to individualizing intervention for each patient.

A Pneumatic Artificial Muscle and Spring Combination System that Assists Ankle Rocker and Transforms Energy into Push-Off Support: A Feasibility Study in Heathy Participants.

Insufficient push-off is a common problem for stroke hemiplegia patients. Assistive systems using extension spring to store energy during stance phase of gait to provide push-off assistance have been developed. However, patients could also suffer poor ankle rocker function; that is, poor dorsiflexion movement in stance phase. In such case, the spring could reversely become a burden for ankle movement. In this research, we proposed a system that combines a pneumatic artificial muscle and a tension spring. The artificial muscle mimics a human's tibialis anterior muscle, while the spring mimicking the Achilles tendon. Upon foot flat event of gait, the artificial muscle contracted to assist ankle rocker function and stretched the spring to store energy simultaneously. After heel off, the artificial muscle extended and the spring was released to provide push-off assistance. A feasibility study in seven healthy participants was conducted to verify assistance effects on their ankle rocker function and push-off movements. The results show significant increase in ankle rocker angle, push-off angle, and push-off torque compared with those during normal walk when the participants were assisted by our system. Therefore, we believe that the proposed system has great potential to assist stroke survivors with problems of poor ankle rocker function and push-off movements.

A Proposal for a New Index to Quantify the Ratio of Near and Far Spatial Neglect Using Immersive Virtual Reality Technology: A Technical Report.

Unilateral spatial neglect (USN) is defined as impaired attention to sensory stimuli on one side, which can exist for near and far spaces combined or independently. Thus, quantifying both near- and far-space neglect is crucial. This study aims to propose an index to quantify the near/far spatial neglect ratio to describe the USN symptoms' characteristics in each patient using immersive virtual reality (VR) technology. An object-detecting task was performed for five USN patients in a three-dimensional VR space. The examiner recorded the positional data of the objects that were recognized by the USN patient using coordinate data. The near/far ratio (NFRatio) was calculated using the proposed equation to quantify the difference in neglect severity in near and far spaces of each patient. Among the patients, four tended to have greater far-space neglect, and one tended to have greater near-space neglect. Moreover, the near/far spatial neglect ratio was shown to vary according to height. This is the first study to propose immersive VR to quantify the near and far spatial neglect. However, further study is needed to assess its reliability and validity and describe its clinical usability. Clinical Relevance- In clinical practice USN symptoms cause neglected symptoms in 3D space so the proposed system will be of high clinical significance if 3D assessment is realized.

Evaluation of a new multitasking platform for endoscopic full-thickness resection.

BACKGROUND: The advent of natural orifice transluminal endoscopic surgery (NOTES) has accelerated the development of new technology in the field of GI endoscopy. Various suturing devices or multitasking platforms are expected to be valuable for endoluminal surgery as well as for NOTES. OBJECTIVE: To evaluate a new multitasking platform in performing endoscopic full-thickness resection (EFTR). DESIGN: Bench-top comparison study. SETTING: Research laboratory study of 10 ex vivo porcine models. INTERVENTION: Ten EFTRs (5 with a double-channel endoscope vs 5 with a new multitasking platform) assisted with percutaneous gastric lifting. Each group was given the task of resecting a full-thickness specimen of the gastric wall including a pseudolesion 10 mm in diameter with an effective margin. MAIN OUTCOME MEASUREMENTS: Outcome measurements included time to perform the procedure, accuracy of the resection, and efficiency for the task. Accuracy was assessed according to variability of the surgical margin and misalignment between the mucosal layer and the seromuscular layer. Efficiency was assessed according to the duty ratio, which is the percentage of time spent for the main purposes compared with the total procedure time. RESULTS: Mean diameter of the specimen was not significantly different between the groups. All other assessment items were significantly superior in group B to those in group A (P < .05). LIMITATIONS: Ex vivo animal model study. CONCLUSION: We were able to perform EFTR procedures precisely and effectively by using a new multitasking platform compared with use of a conventional endoscope in a porcine model. A multitasking platform developed for NOTES procedures would be useful for advanced endoluminal surgery such as endoscopic submucosal dissection or EFTR as well as NOTES.