43 research outputs found
Analysing changeability and time parameters due to levels of Automation in an assembly system
Products of today are becoming increasingly customized. Smaller batches in the assembly and decreasing time limits for set-ups between products are some of the resulting demands on the assembly systems, due to the increasing number of variants in the assembly flow. Consequently, assembly systems have to become more flexible and efficient. When companies adopt automated solutions, there is a need to determine the correct amount of automation. It is also necessary to identify the optimal parts of the value-flow to be automated. In automation decisions it is necessary to consider human resources, as well as mechanical technology and information flow. The paper will discuss the importance of measuring different time parameters in an assembly system. Furthermore an analysis of the ability to change level of automation in an assembly system will be discussed based on theory and a case study exampl
Validation of the complexity index method at three manufacturing companies
In order to manage increasing numbers of product variants, tools that can
reduce or manage production complexity are vital. The paper describes CompleXity Index (CXI), an index-based method and tool that assess the complexity and difficulty of work at an industrial workstation. CXI was validated at three Swedish manufacturing companies studying the correctness of the calculation, usage as a prediction tool and the view of different roles. In all three cases, CXI was seen as a useful tool to evaluate the operator-perceived complexity of a workstation
Validation of the complexity index method at three manufacturing companies
Abstract. In order to manage increasing numbers of product variants, tools that can reduce or manage production complexity are vital. The paper describes CompleXity Index (CXI), an index-based method and tool that assess the complexity and difficulty of work at an industrial workstation. CXI was validated at three Swedish manufacturing companies studying the correctness of the calculation, usage as a prediction tool and the view of different roles. In all three cases, CXI was seen as a useful tool to evaluate the operator-perceived complexity of a workstation
Maternal and newborn plasma oxytocin levels in response to maternal synthetic oxytocin administration during labour, birth and postpartum - a systematic review with implications for the function of the oxytocinergic system
BackgroundThe reproductive hormone oxytocin facilitates labour, birth and postpartum adaptations for women and newborns. Synthetic oxytocin is commonly given to induce or augment labour and to decrease postpartum bleeding.AimTo systematically review studies measuring plasma oxytocin levels in women and newborns following maternal administration of synthetic oxytocin during labour, birth and/or postpartum and to consider possible impacts on endogenous oxytocin and related systems.MethodsSystematic searches of PubMed, CINAHL, PsycInfo and Scopus databases followed PRISMA guidelines, including all peer-reviewed studies in languages understood by the authors. Thirty-five publications met inclusion criteria, including 1373 women and 148 newborns. Studies varied substantially in design and methodology, so classical meta-analysis was not possible. Therefore, results were categorized, analysed and summarised in text and tables.ResultsInfusions of synthetic oxytocin increased maternal plasma oxytocin levels dose-dependently; doubling the infusion rate approximately doubled oxytocin levels. Infusions below 10 milliunits per minute (mU/min) did not raise maternal oxytocin above the range observed in physiological labour. At high intrapartum infusion rates (up to 32 mU/min) maternal plasma oxytocin reached 2-3 times physiological levels.Postpartum synthetic oxytocin regimens used comparatively higher doses with shorter duration compared to labour, giving greater but transient maternal oxytocin elevations. Total postpartum dose was comparable to total intrapartum dose following vaginal birth, but post-caesarean dosages were higher.Newborn oxytocin levels were higher in the umbilical artery vs. umbilical vein, and both were higher than maternal plasma levels, implying substantial fetal oxytocin production in labour. Newborn oxytocin levels were not further elevated following maternal intrapartum synthetic oxytocin, suggesting that synthetic oxytocin at clinical doses does not cross from mother to fetus.ConclusionsSynthetic oxytocin infusion during labour increased maternal plasma oxytocin levels 2-3-fold at the highest doses and was not associated with neonatal plasma oxytocin elevations. Therefore, direct effects from synthetic oxytocin transfer to maternal brain or fetus are unlikely. However, infusions of synthetic oxytocin in labour change uterine contraction patterns. This may influence uterine blood flow and maternal autonomic nervous system activity, potentially harming the fetus and increasing maternal pain and stress
Maternal and newborn plasma oxytocin levels in response to maternal synthetic oxytocin administration during labour, birth and postpartum – a systematic review.
This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the dataBackground: The reproductive hormone oxytocin facilitates labour, birth and postpartum adaptations for women and newborns. Synthetic oxytocin is commonly given to induce or augment labour and to decrease postpartum bleeding.
Aim: To systematically review studies measuring plasma oxytocin levels in women and newborns following maternal administration of synthetic oxytocin during labour, birth and/or postpartum and to consider possible impacts on endogenous oxytocin and related systems.
Methods: Systematic searches of PubMed, CINAHL, PsycInfo and Scopus databases followed PRISMA guidelines, including all peer-reviewed studies in languages understood by the authors. Thirty-fve publications met inclusion cri teria, including 1373 women and 148 newborns. Studies varied substantially in design and methodology, so classical meta-analysis was not possible. Therefore, results were categorized, analysed and summarised in text and tables.
Results: Infusions of synthetic oxytocin increased maternal plasma oxytocin levels dose-dependently; doubling the infusion rate approximately doubled oxytocin levels. Infusions below 10 milliunits per minute (mU/min) did not raise maternal oxytocin above the range observed in physiological labour. At high intrapartum infusion rates (up to 32mU/ min) maternal plasma oxytocin reached 2–3 times physiological levels. Postpartum synthetic oxytocin regimens used comparatively higher doses with shorter duration compared to labour, giving greater but transient maternal oxytocin elevations. Total postpartum dose was comparable to total intrapartum dose following vaginal birth, but post-caesarean dosages were higher Newborn oxytocin levels were higher in the umbilical artery vs. umbilical vein, and both were higher than maternal plasma levels, implying substantial fetal oxytocin production in labour. Newborn oxytocin levels were not further elevated following maternal intrapartum synthetic oxytocin, suggesting that synthetic oxytocin at clinical doses does not cross from mother to fetus.
Conclusions: Synthetic oxytocin infusion during labour increased maternal plasma oxytocin levels 2–3-fold at the highest doses and was not associated with neonatal plasma oxytocin elevations. Therefore, direct efects from synthetic oxytocin transfer to maternal brain or fetus are unlikely. However, infusions of synthetic oxytocin in labour change uterine contraction patterns. This may infuence uterine blood fow and maternal autonomic nervous system activity, potentially harming the fetus and increasing maternal pain and stress.publishedVersio
Maternal plasma levels of oxytocin during breastfeeding - a systematic review
Introduction: Oxytocin is a key hormone in breastfeeding. No recent review on plasma levels of oxytocin in response to breastfeeding is available. Materials and methods: Systematic literature searches on breastfeeding induced oxytocin levels were conducted 2017 and 2019 in PubMed, Scopus, CINAHL, and PsycINFO. Data on oxytocin linked effects and effects of medical interventions were included if available. Results: We found 29 articles that met the inclusion criteria. All studies had an exploratory design and included 601 women. Data were extracted from the articles and summarised in tables. Breastfeeding induced an immediate and short lasting (20 minutes) release of oxytocin. The release was pulsatile early postpartum (5 pulses/10 minutes) and coalesced into a more protracted rise as lactation proceeded. Oxytocin levels were higher in multiparous versus primiparous women. The number of oxytocin pulses during early breastfeeding was associated with greater milk yield and longer duration of lactation and was reduced by stress. Breastfeeding-induced oxytocin release was associated with elevated prolactin levels; lowered ACTH and cortisol (stress hormones) and somatostatin (a gastrointestinal hormone) levels; enhanced sociability; and reduced anxiety, suggesting that oxytocin induces physiological and psychological adaptations in the mother. Mechanical breast pumping, but not bottle-feeding was associated with oxytocin and prolactin release and decreased stress levels. Emergency caesarean section reduced oxytocin and prolactin release in response to breastfeeding and also maternal mental adaptations. Epidural analgesia reduced prolactin and mental adaptation, whereas infusions of synthetic oxytocin increased prolactin and mental adaptation. Oxytocin infusion also restored negative effects induced by caesarean section and epidural analgesia. Conclusions: Oxytocin is released in response to breastfeeding to cause milk ejection, and to induce physiological changes to promote milk production and psychological adaptations to facilitate motherhood. Stress and medical interventions during birth may influence these effects and thereby adversely affect the initiation of breastfeeding
Maternal plasma levels of oxytocin during breastfeeding-A systematic review
Introduction Oxytocin is a key hormone in breastfeeding. No recent review on plasma levels of oxytocin in response to breastfeeding is available. Materials and methods Systematic literature searches on breastfeeding induced oxytocin levels were conducted 2017 and 2019 in PubMed, Scopus, CINAHL, and PsycINFO. Data on oxytocin linked effects and effects of medical interventions were included if available. Results We found 29 articles that met the inclusion criteria. All studies had an exploratory design and included 601 women. Data were extracted from the articles and summarised in tables. Breastfeeding induced an immediate and short lasting (20 minutes) release of oxytocin. The release was pulsatile early postpartum (5 pulses/10 minutes) and coalesced into a more protracted rise as lactation proceeded. Oxytocin levels were higher in multiparous versus primiparous women. The number of oxytocin pulses during early breastfeeding was associated with greater milk yield and longer duration of lactation and was reduced by stress. Breastfeeding-induced oxytocin release was associated with elevated prolactin levels; lowered ACTH and cortisol (stress hormones) and somatostatin (a gastrointestinal hormone) levels; enhanced sociability; and reduced anxiety, suggesting that oxytocin induces physiological and psychological adaptations in the mother. Mechanical breast pumping, but not bottle-feeding was associated with oxytocin and prolactin release and decreased stress levels. Emergency caesarean section reduced oxytocin and prolactin release in response to breastfeeding and also maternal mental adaptations. Epidural analgesia reduced prolactin and mental adaptation, whereas infusions of synthetic oxytocin increased prolactin and mental adaptation. Oxytocin infusion also restored negative effects induced by caesarean section and epidural analgesia. Conclusions Oxytocin is released in response to breastfeeding to cause milk ejection, and to induce physiological changes to promote milk production and psychological adaptations to facilitate motherhood. Stress and medical interventions during birth may influence these effects and thereby adversely affect the initiation of breastfeeding
Maternal plasma levels of oxytocin during physiological childbirth - a systematic review with implications for uterine contractions and central actions of oxytocin
Oxytocin is a key hormone in childbirth, and synthetic oxytocin is widely administered to induce or speed labour. Due to lack of synthetized knowledge, we conducted a systematic review of maternal plasma levels of oxytocin during physiological childbirth, and in response to infusions of synthetic oxytocin, if reported in the included studies. An a priori protocol was designed and a systematic search was conducted in PubMed, CINAHL, and PsycINFO in October 2015. Search hits were screened on title and abstract after duplicates were removed (n = 4039), 69 articles were examined in full-text and 20 papers met inclusion criteria. As the articles differed in design and methodology used for analysis of oxytocin levels, a narrative synthesis was created and the material was categorised according to effects. Basal levels of oxytocin increased 3-4-fold during pregnancy. Pulses of oxytocin occurred with increasing frequency, duration, and amplitude, from late pregnancy through labour, reaching a maximum of 3 pulses/10 min towards the end of labour. There was a maximal 3- to 4-fold rise in oxytocin at birth. Oxytocin pulses also occurred in the third stage of labour associated with placental expulsion. Oxytocin peaks during labour did not correlate in time with individual uterine contractions, suggesting additional mechanisms in the control of contractions. Oxytocin levels were also raised in the cerebrospinal fluid during labour, indicating that oxytocin is released into the brain, as well as into the circulation. Oxytocin released into the brain induces beneficial adaptive effects during birth and postpartum. Oxytocin levels following infusion of synthetic oxytocin up to 10 mU/min were similar to oxytocin levels in physiological labour. Oxytocin levels doubled in response to doubling of the rate of infusion of synthetic oxytocin. Plasma oxytocin levels increase gradually during pregnancy, and during the first and second stages of labour, with increasing size and frequency of pulses of oxytocin. A large pulse of oxytocin occurs with birth. Oxytocin in the circulation stimulates uterine contractions and oxytocin released within the brain influences maternal physiology and behaviour during birth. Oxytocin given as an infusion does not cross into the mother's brain because of the blood brain barrier and does not influence brain function in the same way as oxytocin during normal labour does
An Analysis of the Proactive Approach as a Potential Tool for Adaptability in Production Systems
Competitive systems for manufacturing, especially assembly systems, have to cope with frequent changes of external as well as internal demands. A proactive behaviour in an assembly system should make it capable of rapid changes and have an ability to handle frequent changes and disturbances. During recent decades several different system theories have occurred of which the majority remained theories never taken to actual production solutions. The thesis presents results from four case studies. It is suggested, that the proactivity of an assembly system is strongly influenced by the system’s ability to change the three parameters: 1) level of automation, 2) level of information, 3) level of competence[l3] (among the operators in a defined work area). Proactivity is not easy to describe. However, this[l4] thesis has taken a step in that direction. A general definition of proactivity is “taking action by causing change towards a state and not only reacting to change when it happens”. Another way to phrase this is "to be anticipatory and taking charge of situations”. Proactivity can be described as the ability of preparation for: - Changes and disturbance during operation; - Planned long-term evolution for a sustainable and perfect production system. Such a system consists of technical components efficiently integrated with human operators and has the ability to handle frequent changes. Proactivity in an assembly system is dependent on the following factors: - Continuous changes; - Mandate to allocate resources; - Mandate to do short term planning. The thesis presents a first model for evaluation of different technical resources that contributes to an overall proactive system behaviour. The model has been published but not yet tested.QC 2012011
A model for assessment of proactivity potential in technical resources
The ultimate aim when designing an assembly system is to make it strategically and operationally competitive.Competitive systems for manufacturing, especially assembly systems, have to cope with frequent changes ofdemands. The aim to have a short response time to customer demand, e.i. mass customization, requiresassembly systems that are reliable, have high availability and have ability to produce the right product correctly.This means a combination of short resetting time and ability to vary the systems output of products. A majorchallenge is to minimize the lead-time that directly has influence on order-to-delivery time, while maintainingproduct flexibility and robustness to absorb late market changes. Given that the assembly system is working theway it is supposed to do, the order-to-delivery time is directly dependant on the setup time and the operationtime. The problem is that automated assembly systems have a low availability due to that technical equipmentdoes not work, caused by lack of knowledge, breakdowns, limited ability to perform the operation etc. Thisoften leeds to that when a company needs variant flexibility they keep the assembly system tasks manual.Totally manual assembly system is not the future for competitiveness. Therefore we need to develop assemblysystems that are available and have product flexibility to absorb late market changes, and still have a shortorder-to delivery time. This paper focuses on the level of automation and is a contribution to future evaluationof how technical solutions either support or work counter to proactivity. The result is a model for evaluation oftechnical solutions contribution to proactivityThis paper describes a model for assessment of technology and assembly system solutions that fulfilrequirements for a proactive assembly system. Criteria for proactivity in different technical solutions ofassembly system are reviewed