Sensory–Motor Loop Adaptation in Boolean Network Robots

: Recent technological advances have made it possible to produce tiny robots equipped with simple sensors and effectors. Micro-robots are particularly suitable for scenarios such as exploration of hostile environments, and emergency intervention, e.g., in areas subject to earthquakes or fires. A crucial desirable feature of such a robot is the capability of adapting to the specific environment in which it has to operate. Given the limited computational capabilities of a micro-robot, this property cannot be achieved by complicated software but it rather should come from the flexibility of simple control mechanisms, such as the sensory-motor loop. In this work, we explore the possibility of equipping simple robots controlled by Boolean networks with the capability of modulating their sensory-motor loop such that their behavior adapts to the incumbent environmental conditions. This study builds upon the cybernetic concept of homeostasis, which is the property of maintaining essential parameters inside vital ranges, and analyzes the performance of adaptive mechanisms intervening in the sensory-motor loop. In particular, we focus on the possibility of maneuvering the robot's effectors such that both their connections to network nodes and environmental features can be adapted. As the actions the robot takes have a feedback effect to its sensors mediated by the environment, this mechanism makes it possible to tune the sensory-motor loop, which, in turn, determines the robot's behavior. We study this general setting in simulation and assess to what extent this mechanism can sustain the homeostasis of the robot. Our results show that controllers made of random Boolean networks in critical and chaotic regimes can be tuned such that their homeostasis in different environments is kept. This outcome is a step towards the design and deployment of controllers for micro-robots able to adapt to different environments

Intragastric gastric band migration: erosion: an analysis of multicenter experience on 177 patients

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) has proven to be a safe and effective surgical treatment for morbid obesity. It can be a simple, fast, reversible, anatomy-preserving procedure. Despite these advantages, its long-term efficacy came into question by the occurrence of complications such as intragastric band migration. Consistent information regarding this complication is still lacking. Treatment for migration is still being debated as well. Most of the inconsistencies of these data stem from the very low number of patients reported in single-center experiences or case reports. Lack of multicenter experience is evident. The aim of this study was to perform a retrospective analysis of data on intragastric migration in a large multicenter cohort of patients who underwent LAGB. METHODS: A retrospective multicenter study on LAGB patients was performed. Data had been entered into a prospective database of the Italian Group for LapBand(®) (GILB) since January 1997. Pars flaccida and perigastric positioning were considered along with different kinds of gastric bands by the same manufacturer. Time of diagnosis, mean body mass index (BMI), presentation symptoms, and conservative and surgical therapy of intragastric migration were considered. RESULTS: From January 1997 to December 2009, a total of 6,839 patients underwent LAGB and their data were recorded [5,660 females, 1,179 males; mean age 38.5 ± 18.2 years (range 21-62 years); mean BMI = 46.7 ± 7.7 kg/m(2) (range 37.3-68.3); excess weight (EW) 61.8 ± 25.4 kg (range 36-130); %EW 91.1 ± 32.4 % (range 21-112 %)]. A total of 177 of 6,839 (2.5 %) intragastric erosions were observed. According to the postoperative time of follow-up, the diagnosis of intragastric migration was made in 74 (41.8 %), 14 (7.9 %), 38 (21.4 %), 40 (22.6 %), 6 (3.4 %), and 4 (2.2 %) banded patients at 6-12, 24, 36, 48, 60, and 72 months after banding, respectively. Most of intragastric band migration during the first 2 years occurred in bands with no or a few milliliters of filling. In patients with late erosion, the bands were adjusted several times; no band was overfilled but one was filled to the maximum or submaximum with a maximum of two adjustments. Erosions diagnosed during the first 24 months were related to the experience of the surgical staff, while late erosions were not. CONCLUSIONS: Intragastric band migration or band erosion is a rare, disturbing, and usually not life-threatening complication of gastric banding. Its pathogenesis is probably linked to different mechanisms in early (technical failure in retrogastric passage) or late (band management) presentation. It is usually asymptomatic and there is no pathognomonic presentation. A wide range of therapeutic options are available, from simple endoscopic or laparoscopic removal to early or late band replacement or other bariatric procedure. More experience and more studies are needed to lower its presentation rate and definitively clarify its pathogenesis to address the right therapeutic option

Improvement in health-related quality of life in first year after laparoscopic adjustable gastric banding

BACKGROUND: We analyzed the health-related quality of life (HRQOL) and its determinants in the first year after laparoscopic adjustable gastric banding (LAGB). The setting was 10 Italian public and private bariatric surgery centers. METHODS: Data collected in an ongoing, prospective, 3-year multicenter Italian study on the changes in HRQOL after LAGB were used. HRQOL was investigated using the Medical Outcomes Study Short-Form 36 questionnaire. Hunger, satiety, and the self-perceived effects of LAGB were recorded. RESULTS: A total of 334 patients were enrolled. The follow-up rate was 92.2%. The percentage of excess weight loss was 39.6% \ub1 25.8%, with very few side effects or complications. Hunger in the morning (0-10 scale) was 4.5 \ub1 2.7 before surgery and 3.8 \ub1 2.4 after 1 year (P <.001). Satiety after a meal (0-10 scale) was 7.1 \ub1 2.7 before surgery and 8.2 \ub1 1.9 at 1 year (P <.001). The self-perceived effect of LAGB on caloric intake (0-10 scale) was 8.4 \ub1 1.9 after 1 year. The scores for the 8 Medical Outcomes Study Short-Form 36 subscales were significantly improved after surgery. The physical component summary score was 52.6 \ub1 11.9 at baseline and 79.1 \ub1 15.6 after 1 year (P <.001). The corresponding mental component summary scores were 52.2 \ub1 12.3 and 76.5 \ub1 17.2 (P <.001). Greater physical component summary improvement was independently associated with a low initial physical component summary (P <.001), high satiety (P = .002), a high percentage of excess weight loss (P = .013), and a high self-perceived effect of the LAGB (P = .026). Greater mental component summary improvement was associated with a low initial mental component summary (P <.001), high satiety (P <.001), a low frequency of heartburn (P = .004), and a high percentage of excess weight loss (P = .012). CONCLUSIONS: Significant improvements in HRQOL were observed in the first year after LAGB. A poor baseline HRQOL, a high efficacy of the banding in eating control, and better weight loss might influence HRQOL change

Improvement in health-related quality of life in first year after laparoscopic adjustable gastric banding

Background: We analyzed the health-related quality of life (HRQOL) and its determinants in the first year after laparoscopic adjustable gastric banding (LAGB). The setting was 10 Italian public and private bariatric surgery centers. Methods: Data collected in an ongoing, prospective, 3-year multicenter Italian study on the changes in HRQOL after LAGB were used. HRQOL was investigated using the Medical Outcomes Study Short- Form 36 questionnaire. Hunger, satiety, and the self-perceived effects of LAGB were recorded. Results: A total of 334 patients were enrolled. The follow-up rate was 92.2%. The percentage of excess weight loss was 39.6% 25.8%, with very few side effects or complications. Hunger in the morning (0–10 scale) was 4.5 2.7 before surgery and 3.8 2.4 after 1 year (P .001). Satiety after a meal (0–10 scale) was 7.1 2.7 before surgery and 8.2 1.9 at 1 year (P .001). The self-perceived effect of LAGB on caloric intake (0–10 scale) was 8.4 1.9 after 1 year. The scores for the 8 Medical Outcomes Study Short-Form 36 subscales were significantly improved after surgery. The physical component summary score was 52.6 11.9 at baseline and 79.1 15.6 after 1 year (P .001). The corresponding mental component summary scores were 52.2 12.3 and 76.5 17.2 (P .001). Greater physical component summary improvement was independently associated with a low initial physical component summary (P .001), high satiety (P .002), a high percentage of excess weight loss (P .013), and a high self-perceived effect of the LAGB (P .026). Greater mental component summary improvement was associated with a low initial mental component summary (P .001), high satiety (P .001), a low frequency of heartburn (P .004), and a high percentage of excess weight loss (P .012). Conclusions: Significant improvements in HRQOL were observed in the first year after LAGB. A poor baseline HRQOL, a high efficacy of the banding in eating control, and better weight loss might influence HRQOL changes. (Surg Obes Relat Dis 2012;8:260 –268.) © 2012 American Society for Metabolic and Bariatric Surgery. All rights reserved

Improvement in Health-Related Quality of Life (HR-QOL) in the First Year after Laparoscopic Adjustable Gastric Banding (LAGB)

Background: We analyzed the health-related quality of life (HRQOL) and its determinants in the first year after laparoscopic adjustable gastric banding (LAGB). The setting was 10 Italian public and private bariatric surgery centers. Methods: Data collected in an ongoing, prospective, 3-year multicenter Italian study on the changes in HRQOL after LAGB were used. HRQOL was investigated using the Medical Outcomes Study Short- Form 36 questionnaire. Hunger, satiety, and the self-perceived effects of LAGB were recorded. Results: A total of 334 patients were enrolled. The follow-up rate was 92.2%. The percentage of excess weight loss was 39.6% 25.8%, with very few side effects or complications. Hunger in the morning (0–10 scale) was 4.5 2.7 before surgery and 3.8 2.4 after 1 year (P .001). Satiety after a meal (0–10 scale) was 7.1 2.7 before surgery and 8.2 1.9 at 1 year (P .001). The self-perceived effect of LAGB on caloric intake (0–10 scale) was 8.4 1.9 after 1 year. The scores for the 8 Medical Outcomes Study Short-Form 36 subscales were significantly improved after surgery. The physical component summary score was 52.6 11.9 at baseline and 79.1 15.6 after 1 year (P .001). The corresponding mental component summary scores were 52.2 12.3 and 76.5 17.2 (P .001). Greater physical component summary improvement was independently associated with a low initial physical component summary (P .001), high satiety (P .002), a high percentage of excess weight loss (P .013), and a high self-perceived effect of the LAGB (P .026). Greater mental component summary improvement was associated with a low initial mental component summary (P .001), high satiety (P .001), a low frequency of heartburn (P .004), and a high percentage of excess weight loss (P .012). Conclusions: Significant improvements in HRQOL were observed in the first year after LAGB. A poor baseline HRQOL, a high efficacy of the banding in eating control, and better weight loss might influence HRQOL changes. (Surg Obes Relat Dis 2012;8:260 –268.) © 2012 American Society for Metabolic and Bariatric Surgery. All rights reserved

Determinants of health-related quality of life (HR-QoL) in morbid obese candidates to gastric banding: baseline results from the quality study

Objective. To analyse determinants of self reported health-related quality of life (HR-QoL) in morbid obese patients candidates to laparoscopic adjustable gastric banding (LAGB). Methods. Determinants of HR-QoL were investigated in 383 morbid obese patients (82 M and 301 F) with BMI\uf0b340 kg/m2 (BMI\uf0b335 kg/m2 if complicated obesity) and age 18-60 years. HR-QoL was determined with the SF-36 questionnaire. Determinants of the two summary measures of SF-36 (physical component and mental compoment) were analysed by stepwise multiple linear regression analysis with age, BMI, physical comorbidites, mental comorbidites and eating behaviour disorders as independent variables. Physical comorbities (diabetes, hypertension, hypertriglyceridemia, low HDL, sleep apnea and osteoarthritis) were coded as present or absent on the basis of simple diagnostic clinical criteria. Mental comorbidities (depression) and eating behaviour disorders (binge eating, sweet eating and nibbling) on the basis of a unstructured clinical interview. Results. Mean age was 38.8\ub110.2 years and mean BMI was 41.5\ub15.4 kg/m2. Scores in the 8 SF-36 subscales were lower in women than in men and lower than in the general Italian population. However, 18.4-43.5% of the participants had HR-QoL levels above the normative values, but 12 to 43% of them, depending on the scale. In both genders, low scores in the mental component of the SF-36 were associated to the presence of depression and eating behaviour disorders and not to physical comorbidities or BMI levels. Low physical self-perceived well being was associated to high BMI levels in men and to depression, hypertension and hypertriglyceridemia in women. Conclusion. HR-QoL was poor in morbid obese candidates to LAGB, particularly in women, and was negatively affected more by mental comorbidites and eating behaviour disorders than by physical comorbidities or BMI level

Determinants of health-related quality of life in morbidy obese candidates to gastric banding : baseline results from the quality study

Objective. To analyse determinants of self reported health-related quality of life (HR-QoL) in morbid obese patients candidates to laparoscopic adjustable gastric banding (LAGB). Methods. Determinants of HR-QoL were investigated in 383 morbid obese patients (82 M and 301 F) with BMI\uf0b340 kg/m2 (BMI\uf0b335 kg/m2 if complicated obesity) and age 18-60 years. HR-QoL was determined with the SF-36 questionnaire. Determinants of the two summary measures of SF-36 (physical component and mental compoment) were analysed by stepwise multiple linear regression analysis with age, BMI, physical comorbidites, mental comorbidites and eating behaviour disorders as independent variables. Physical comorbities (diabetes, hypertension, hypertriglyceridemia, low HDL, sleep apnea and osteoarthritis) were coded as present or absent on the basis of simple diagnostic clinical criteria. Mental comorbidities (depression) and eating behaviour disorders (binge eating, sweet eating and nibbling) on the basis of a unstructured clinical interview. Results. Mean age was 38.8\ub110.2 years and mean BMI was 41.5\ub15.4 kg/m2. Scores in the 8 SF-36 subscales were lower in women than in men and lower than in the general Italian population. However, 18.4-43.5% of the participants had HR-QoL levels above the normative values, but 12 to 43% of them, depending on the scale. In both genders, low scores in the mental component of the SF-36 were associated to the presence of depression and eating behaviour disorders and not to physical comorbidities or BMI levels. Low physical self-perceived well being was associated to high BMI levels in men and to depression, hypertension and hypertriglyceridemia in women. Conclusion. HR-QoL was poor in morbid obese candidates to LAGB, particularly in women, and was negatively affected more by mental comorbidites and eating behaviour disorders than by physical comorbidities or BMI level