Feedback Type May Change the EMG Pattern and Kinematics During Robot Supported Upper Limb Reaching Task.

Haptic interfaces and virtual reality (VR) technology have been increasingly introduced in rehabilitation, facilitating the provision of various feedback and task conditions. However, correspondence between the feedback/task conditions and movement strategy during reaching tasks remains a question. To investigate movement strategy, we assessed velocity parameters and peak latency of electromyography. Ten neuromuscularly intact volunteers participated in the measurement using haptic interface and VR. Concurrent visual feedback and various terminal feedback (e.g., visual, haptic, visual and haptic) were given. Additionally, the object size for the reaching task was changed. The results demonstrated terminal haptic feedback had a significant impact on kinematic parameters; showed [Formula: see text] s ([Formula: see text]) shorter movement time and [Formula: see text] m/s ([Formula: see text]) higher mean velocity compared to no terminal feedback. Also, smaller peak latency was observed in different muscle regions based on the object size.

Histology of metastatic colorectal cancer in a lymph node.

BACKGROUND: A primary colorectal cancer (CRC) tumor can contain heterogeneous cancer cells. As clones of cells with different properties metastasize to lymph nodes (LNs), they could show different morphologies. Cancer histologies in LNs of CRC remains to be described. METHODS: Our study enrolled 318 consecutive patients with CRC who underwent primary tumor resection with lymph node dissection between January 2011 and June 2016. 119 (37.4%) patients who had metastatic LNs (mLNs) were finally included in this study. Cancer histologies in LNs were classified and compared with pathologically diagnosed differentiation in the primary lesion. The association between histologies in lymph node metastasis (LNM) and prognosis in patients with CRC was investigated. RESULTS: The histologies of the cancer cells in the mLNs were classified into four types: tubular, cribriform, poorly differentiated, and mucinous. Same degree of pathologically diagnosed differentiation in the primary tumor produced various histological types in LNM. In Kaplan-Meier analysis, prognosis was worse in CRC patients with moderately differentiated adenocarcinoma who had at least some mLN also showing cribriform carcinoma than for those whose mLNs all showed tubular carcinoma. CONCLUSIONS: Histology in LNM from CRC might indicate the heterogeneity and malignant phenotype of the disease.

Torque Estimation of Knee Flexion and Extension Movements From a Mechanomyogram of the Femoral Muscle.

A mechanomyogram is a visualization of the mechanical signal from the surface of a muscle when the muscle is contracted. The setup of the mechanomyography (MMG) measurement is simpler than the setup for surface electromyography (sEMG) measurement and is less affected by sweating. However, torque estimation based on a mechanomyogram involves significant noise, which is an important issue. Therefore, we propose a regression analysis method to estimate the torque of the knee joint during voluntary movement based on the MMG signal. The proposed method differs from conventional methods because it integrates the MMG sensor responses at four locations: anterior, posterior, and medial/lateral just above the main operating muscle. This method focuses on the acceleration response characteristics, which change slightly depending on the location of the MMG sensor. Support vector regression was performed on the root mean square (RMS) of the MMG signals, which were processed by a low-pass filter. Two-channel estimation with an increased number of MMG sensors for the leading and antagonist muscles improved the conventional method, and four-channel estimation with medial and lateral sensors further improved the performance. These results show that the estimation performance of the proposed method does not significantly differ from that of the surface electromyogram.

Oncolytic virotherapy with SOCS3 enhances viral replicative potency and oncolysis for gastric cancer.

Oncolytic virotherapy is an encouraging treatment using herpes simplex virus (HSV) for gastric cancer patients. To treat gastric cancer, we generated and evaluated the efficacy of an attractive type of oncolytic HSV expressing the suppressor of cytokine signaling 3 (SOCS3). We constructed a third-generation type of oncolytic HSV (T-SOCS3) arming with SOCS3 by a bacterial artificial chromosome (BAC) system. We examined the viral replicative intensification and oncolysis of T-SOCS3 for human gastric cancer cell lines ex vivo. T-SOCS3 enhanced its replication and potentiated its cell-killing effect for MKN1 human gastric cancer cell lines, which are resistant to a non-armed third-generation type of oncolytic HSV (T-01) ex vivo. T-SOCS3 also induced the destruction within human gastric cancer specimens. Armed oncolytic HSVs expressing SOCS3 may be an efficacious therapeutic agent for gastric cancer treatment.

Haptic Coupling in Dyads Improves Motor Learning in a Simple Force Field.

In dyadic motor learning, pairs of people learn the same motion while their limbs are loosely coupled together using haptic devices. Such coupled learning has been shown to outperform solo learning (including robot-guided learning) for simple one-degree-of-freedom tasks. However, results from more complex tasks are limited and sometimes conflicting. We thus evaluated coupled learning in a two-degree-of-freedom tracking task where participants also had to compensate for a simple force field. Participant pairs were split into two groups: an experiment group that experienced a compliant haptic coupling between participants' hands and a control group that did not. The study protocol consisted of 70 repetitions of 18.9-second tracking trials: 10 initial solo trials with no coupling, 50 "learning" trials (where participants in the experiment group were coupled), and 10 final solo trials with no coupling. The experiment group (coupled) improved their solo tracking performance both in the presence (p = 0.008) and absence (p <; 0.001) of the force field; however, the control group (no coupling) only improved their solo performance in the absence of the force field (p <; 0.001) but not in the presence of the field (p = 0.81). This suggests that dyadic motor learning can outperform solo learning for two-dimensional tracking motions in the presence of a simple force field, though the mechanism by which learning is improved is not yet clear.Clinical Relevance-As motor learning is critical for applications such as motor rehabilitation, dyadic training could be used to achieve a better overall outcome and a faster learning speed in these applications compared to solo training.

Movement strategy and EMG activities of the upper extremity at assisted reaching exercise with a 7 DOF collaborative robot.

Recovering of upper extremity functions is important for stroke patients to perform various tasks in daily life. For better rehabilitation outcomes and accurate measurement, robot assisted exercises have been developed. However, there are limited number of studies related to arm muscles activities corresponding to task complexity. We conducted a preliminary case study on strategy and activities of upper extremity muscles in a healthy volunteer at reaching exercise with haptic feedback by a robot with seven degree-of-freedom when a different target was presented in the virtual environment. Impedance control for Franka Emika Panda robot arm has been developed. The study protocol consisted of 4 sets of 40 reaching trials. The trials had two modes with two different feedback: big target task mode and the small target task mode. In each mode both options, with/without haptic feedback were tested. The preliminary results suggest that different distance to target and target's size is related to the change of activation order and intensity of muscle activities at reaching task. Additionally, the haptic feedback required different activation order and higher intensity regardless of the task difficulty.

Hysteresis Compensation in Force/Torque Sensors Using Time Series Information.

The purpose of this study is to compensate for the hysteresis in a six-axis force sensor using signal processing, thereby achieving high-precision force sensing. Although mathematical models of hysteresis exist, many of these are one-axis models and the modeling is difficult if they are expanded to multiple axes. Therefore, this study attempts to resolve this problem through machine learning. Since hysteresis is dependent on the previous history, this study investigates the effect of using time series information in machine learning. Experimental results indicate that the performance is improved by including time series information in the linear regression process generally utilized to calibrate six-axis force sensors.

Visual Biofeedback of Force Information for Eccentric Training of Hemiplegic Patients.

Motor learning issues for hemiplegics not only include motor impairments such as spastic paralysis, but reportedly also an inability to appropriately recognize somatic sensations. In this regard, biofeedback of movement information through visual information and auditory information has been found effective as a method for drawing attention to appropriate somatic sensations. In this context, here, we propose a novel eccentric training system utilizing visual biofeedback of force information. We first develop a compact and highly portable rehabilitation robot for home use. The robot estimates the force on the tiptoe without the use of a force sensor, and a display connected to the robot presents the force information to the trainee. Clinical trials with two chronic hemiplegics have been conducted. The results show that the timed up and go tests of both trainees are shortened after training twice a week for three weeks (six times in total). Simultaneously, the co-contraction index scores of the tibialis anterior and gastrocnemius muscles decrease. These findings in conjunction with previous results suggest that training with visual biofeedback of force information may enhance reciprocal inhibition of the tibialis anterior muscle and reduces co-contraction.

Robot-Assisted Eccentric Contraction Training of the Tibialis Anterior Muscle Based on Position and Force Sensing.

The purpose of this study was to determine the clinical effects of a training robot that induced eccentric tibialis anterior muscle contraction by controlling the strength and speed. The speed and the strength are controlled simultaneously by introducing robot training with two different feedbacks: velocity feedback in the robot controller and force bio-feedback based on force visualization. By performing quantitative eccentric contraction training, it is expected that the fall risk reduces owing to the improved muscle function. Evaluation of 11 elderly participants with months training period was conducted through a cross-over comparison test. The results of timed up and go (TUG) tests and 5 m walking tests were compared. The intergroup comparison was done using the Kruskal-Wallis test. The results of cross-over test indicated no significant difference between the 5-m walking time measured after the training and control phases. However, there was a trend toward improvement, and a significant difference was observed between the training and control phases in all subjects.

Triangulating stapling vs functional end-to-end stapling for cervical esophagogastric anastomosis after esophagectomy for thoracic esophageal cancer: study protocol for a randomized controlled trial.

BACKGROUND: Several studies have reported that the triangulating stapling method decreases the incidence of anastomotic stricture after esophagectomy. Our previous randomized controlled trial, however, could not confirm the superiority of the triangulating stapling (TS) method over the circular stapling (CS) method in terms of postoperative anastomotic stricture rate. Recently, the functional end-to-end stapling (FEES) method for cervical anastomosis after esophagectomy was developed, and lower anastomotic stricture rates with FEES have been reported than for our previously experienced anastomotic methods. To investigate the optimal anastomotic method, we now compare the TS method with the FEES method for cervical anastomosis regarding decrease in anastomotic stricture after esophagectomy for thoracic esophageal cancer. METHODS: This is a randomized, single-center clinical trial designed to examine the superiority of the FEES method over the TS method for esophageal cancer patients. The primary endpoint is reduction of anastomotic stricture of cervical esophagogastric anastomosis within 12 months after esophagectomy. Secondary endpoints include overall postoperative morbidity within the first 12 months after esophagectomy, incidence of anastomotic leakage, aspiration pneumonia, or reflux esophagitis, and quality of life assessment as measured by the FACT-E at 12 months after esophagectomy. The incidence rate of anastomotic stricture of the TS method was 20% and this rate of the FEES method was estimated to be 4% in our preliminary study. We calculated sample size with a beta error of 0.20 and an alpha error of 0.05. We have been enrolling 125 patients in this trial to either the TS group or the FEES group since January 2017. DISCUSSION: This study should help to define the optimal anastomotic method for cervical esophagogastric anastomosis after esophagectomy in patients with esophageal cancer. The FEES method, if proven to be superior to the TS method, can be implemented routinely for esophageal cancer patients with gastric-conduit reconstruction after esophagectomy. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trial Registry ( UMIN 000025632 ). Registered on 13 January 2017.

Conversion Surgery for Gastric Cancer with Peritoneal Metastasis Based on the Diagnosis of Second-Look Staging Laparoscopy.

BACKGROUND: Patients with positive peritoneal cytology (CY1) or peritoneal dissemination (P1) have significantly poor prognosis. We performed pre-therapeutic staging laparoscopy (SL) to diagnose peritoneal metastasis for patients with advanced gastric cancer. When peritoneal metastasis disappears by chemotherapy for patients with CY1 or P1, we have intention to perform conversion surgery (CS). This study aims to clarify the clinical significance of CS for such patients. METHODS: We retrospectively analyzed clinical outcomes of 115 patients with advanced gastric cancer (large type 3, type 4, serosa-invasion) who underwent SL between 2005 and 2014. Disappearance of peritoneal metastasis was confirmed by second-look SL. RESULTS: CY0P0, CY1P0, and P1 were found in 56, 26, and 33 patients, respectively. In patients with CY1P0, 12 patients (66.7%) underwent CS (R0) as peritoneal cytology turned negative. All cases received S-1-based regimens, with median five treatment courses. The survival of patients with CS was significantly longer than those without CS (median survival time (MST); 41 vs. 11 months, respectively, P < 0.001). We observed no difference in overall survival between patients who underwent CS and patients with CY0P0 at the first SL (P = 0.913). All patients with P1 received chemotherapy. As peritoneal metastasis of five patients (15.2%) disappeared by chemotherapy, those patients underwent the CS (R0). The survival of patients who underwent CS was significantly longer than those who did not (MST; 31 vs. 10 months, respectively, P = 0.034). CONCLUSION: This study suggests that conversion surgery contributes to improvement in survival of patients with peritoneal metastasis.

Control with Adjusted Pulse Frequency and Amplitude in Functional Electrical Stimulation.

In this paper, we describe the control of a body using functional electrical stimulation (FES) by adjusting pulse amplitude and frequency. FES is a technique used in the rehabilitation of spinal injury patients and application development for healthy people. However, control using the FES involves a delay time, resulting a high-frequency vibration (called chattering). In this paper, we propose that the control performance can be improved by adjusting the frequency in addition to the conventional pulse amplitude adjustment. In experiments, target values were controlled using subjects, and the performance of the proposed method was verified. Results confirmed that chattering is suppressed by the proposed method.

Endoscopic treatment of esophageal fistulas after esophagectomy with injection of an alpha-cyanoacrylate monomer: a phase II study.

Background and study aims Interventional endoscopic treatments including the application of glue are becoming more frequently used for the treatment of esophageal fistulas. However, there are no prospective studies of endoscopic treatment for esophageal fistulas. This prospective study aims to investigate the efficacy and safety of endoscopic injection of alpha-cyanoacrylate monomer for intractable esophageal fistulas. Patients and methods This single-center prospective phase II trial included patients with more than 1 wk of conservative medical treatment for intractable esophageal fistulas after esophagectomy. In the image-guided therapy suite, a mixture of alpha-cyanoacrylate monomer and oily contrast agent in a ratio of 0.3 to 1.7 mL was endoscopically injected through the fistula. Results Twenty-five patients who underwent esophagectomy at Wakayama Medical University Hospital were enrolled in this study. The primary disease was esophageal cancer in 16 patients (64 %) and gastric cancer in the remaining 9 patients (36 %). Complete closure of the esophageal fistula was performed in 22 patients after endoscopic injection of alpha-cyanoacrylate monomer. The overall success rate was 88 %. There was no fistula recurrence in any successful closure cases. Three patients with failed esophageal fistula closure had esophageal cancer with cervical esophageal fistulas and required reoperation of the fistulectomy under general anesthesia. No complications associated with this endoscopic treatment were detected. Conclusions Endoscopic treatment with injection of alpha-cyanoacrylate monomer facilitated healing of post-esophagectomy fistula in 88 % of patients without complications. This suggests that the treatment is effective and safe for patients with esophageal fistulas.

Prevention of Internal Hernia During Robotic Total Gastrectomy for Gastric Cancer.

BACKGROUND: Postoperative internal hernia (IH) is a potentially life-threatening acute protrusion of viscus through an iatrogenic mesenteric defect. In our retrospective study of 1943 consecutive gastric cancer (GC) patients who had undergone surgery, the incidence of IH after laparoscopic total gastrectomy (LTG) was 4.9%.1 This high incidence seems to be caused by decreased adhesion formation after LTG. There is no consensus regarding orifice management during robotic total gastrectomy (RTG). We therefore developed a new procedure for IH prevention during RTG. METHODS: We performed RTG with antecolic Roux-en-Y reconstruction using the da Vinci S system (Intuitive, Sunnyvale, CA). We chose an intracorporeal side-to-side esophagojejunostomy (overlap method).2 First, mesenteric defect of jejunojejunostomy was closed under direct vision following retrieval of the stomach. Second, the esophagus hiatus and Petersen's defect were closed under laparoscopic vision using robotic suture.3 Finally, the duodenal stump and the Roux limb were fixed to prevent torsion of the Roux limb. RESULTS: We performed this procedure on five patients between May and October 2017. The median duration of surgery was 395 min (range, 319-442 min), median bleeding was 60 ml (range, 35-140 ml). There were no anastomosis-related complications higher than Clavien-Dindo grade II in any patients.4 Although the follow-up period is less than 1 year, no IH after RTG has been observed in any patients. CONCLUSION: Regarding short-term surgical outcomes, this procedure is recommended for GC patients who undergo RTG. However, more long-term follow-up for patients who have undergone RTG with closure of all mesenteric defects is required.

Usefulness of indocyanine green fluorescence imaging: A case of laparoscopic distal gastrectomy after distal pancreatectomy with splenectomy.

Safe preservation of the remnant stomach during distal gastrectomy in patients who have undergone distal pancreatectomy is important. During distal pancreatectomy, the splenic artery that supplies arterial blood to the cardiac part of stomach is resected. Previous reports suggested that blood flow to the remnant stomach may be insufficient when supplied by only the left inferior phrenic artery. In the present case, a 79-year-old woman who underwent distal pancreatectomy with splenectomy 20 years before she was diagnosed with gastric cancer and referred to our hospital. We performed laparoscopic distal gastrectomy and Roux-en-Y reconstruction because preoperative CT scan indicated a developed left inferior phrenic artery. To evaluate the blood supply, we employed indocyanine green fluorescence and were able to safely preserve the remnant stomach. Our experience suggests that indocyanine green fluorescence is potentially useful for evaluating blood flow to the remnant stomach.

Internal Hernia After Laparoscopic Total Gastrectomy for Gastric Cancer.

PURPOSE: The aim of this study was to clarify internal hernia (IH) characteristics after laparoscopic gastrectomy. MATERIALS AND METHODS: This was a retrospective study of 1943 consecutive gastric cancer patients who underwent surgery at our institute between 2004 and 2015. Since 2013, our technique includes antecolic Roux-en-Y (RY) with closure of all mesenteric defects during laparoscopic total gastrectomy (LTG) as standard. RESULTS: Postoperative IH was only detected in patients who underwent total gastrectomy with RY reconstruction. Furthermore, the incidence of IH was significantly higher after LTG than after open total gastrectomy (4.9% vs. 1.0%; P=0.005). IH after LTG occurred in 8.0% of patients before standardization with closure of the mesenteric defects, but no IH was observed after standardization (P=0.047). CONCLUSIONS: Closure of all mesenteric defects is recommended for gastric cancer patients who undergo LTG with antecolic RY. Registration number: UMIN000009163/000025029 (www.umin.ac.jp/ctr/).

Gait training assist system of a lower limb prosthetic visualizing muscle activation pattern using a color-depth sensor.

Some unilateral lower-limb amputees load the intact limb more than the prosthetic limb. This can cause chronic pains, fatigue, lumbago, and joint diseases, including knee osteoarthritis. To avoid and counteract these symptoms it is necessary to improve their asymmetric gait. Increasing the function of the hip abductor muscle is important to maintaining symmetrical weight distribution. Therefore, the purpose of this study is to develop a training assist system, which estimates and visualizes an abductor muscle by using a color-depth sensor. To estimate the muscle activation, first, the floor reaction force is calculated using a simple dynamic model. Then, the hip torque is calculated using joint angles. The floor reaction force and, the muscle length are calculated based on a human musculoskeletal model. Muscle activity is estimated by these parameters. Evaluation experiments of this proposed method were performed on healthy persons and unilateral trans femoral amputees, and the effectiveness of this proposed algorithm has been confirmed.

Rehabilitation for hemiplegia using an upper limb training system based on a force direction.

Hemiplegia patients have complete paralysis of half their body, and encounter many challenges in living an independent life. Rehabilitation of the lower body is more important than that of the upper body for independent living; thus, recovering upper body functions of their paralyzed side is not enough. Rehabilitation robots may be used to assist training without therapists. In this study, a small portable rehabilitation robot was developed for use at home, and a new training method was proposed. This robot consists on an omni wheel mechanism and a force sensor, and is capable of deciding the motion based on the force value. Voluntary movement of a hemiplegia patient is recovered by the rehabilitation robot and proposed training method. Thus, verification experiments were performed using participants with hemiplegia. The CCI (Co-Contraction Index) from after training were smaller than ones of before training, thus the movement skills of the participants improved with respect to controlling force direction and magnitude. Moreover, manual function test (MFT) scores increased as reflected by improvements in the motor function of the upper limb using the proposed training method.

Inverse estimation of multiple muscle activations based on linear logistic regression.

This study deals with a technology to estimate the muscle activity from the movement data using a statistical model. A linear regression (LR) model and artificial neural networks (ANN) have been known as statistical models for such use. Although ANN has a high estimation capability, it is often in the clinical application that the lack of data amount leads to performance deterioration. On the other hand, the LR model has a limitation in generalization performance. We therefore propose a muscle activity estimation method to improve the generalization performance through the use of linear logistic regression model. The proposed method was compared with the LR model and ANN in the verification experiment with 7 participants. As a result, the proposed method showed better generalization performance than the conventional methods in various tasks.