Differential Impact of Central Venous Catheters versus Arteriovenous Fistulae on Quality of Life among Irish Haemodialysis Patients.

Background: Arteriovenous fistulae (AVF) have superior clinical outcomes compared with central venous catheters (CVC) among patients undergoing hemodialysis (HD). Yet, there is increasing recognition that health-related quality of life (HRQoL) may be more important to patients than survival and that differences may exist between AVF and CVCs in this regard. This study compared HRQoL between AVF and CVC in an Irish cohort. Methods: We conducted a cross-sectional survey among prevalent patients undergoing hemodialysis (N=119) dialyzing with either an AVF or CVC at a regional program. The Short Form 36 (SF-36) and a validated Vascular Access Questionnaire (SF-VAQ) compared QoL between AVF and CVC in domains of physical functioning, social functioning, and dialysis complications. Multivariable logistic regression compared differences between groups for outcomes of physical functioning, social functioning, and dialysis complications expressed as adjusted odds ratios and 95% CI. Results: Mean age was 66.6 years; 52% were using an AVF and 48% had a CVC. Patients dialyzing with an AVF were more satisfied with their access when asked directly (6.2 versus 5.0; P<0.01). Physical functioning scores for bleeding, swelling, and bruising were significantly higher for AVF than CVC (P=0.001, P=0.001, and P<0.001, respectively). In contrast, patients with a CVC reported greater difficulties in bathing and showering than those using an AVF (4.4 versus 2.0; P<0.001), whereas patients with an AVF expressed greater concerns with physical appearances. Compared with AVF, CVC users were less likely to report difficulties in physical functioning (OR=0.35; 95% CI, 0.12 to 0.94; P=0.04) but more likely to report dialysis complications (OR=1.94; 95% CI, 0.69 to 5.87; P=0.22). Conclusions: Vascular access contributes to HRQoL in hemodialysis. CVCs are associated with fewer difficulties from bleeding and bruising but greater negative effect on social activities, including bathing and showering. Overall, patients with a CVC had lower dissatisfaction scores than patients with an AVF when all three domains were added. Innovation in vascular access design and engineering may confer benefits and improve patient comfort on HD.

Using personas to exploit environmental attitudes and behaviour in sustainable product design.

The aim of this research was to study the relationship between user sustainable design attitudes versus behaviour, and to develop and test environmental personas as design tools. Current approaches towards environmentally sustainable design are primarily focused on capturing the environmentally conscious and pro-environmental consumers, or changing the attitude and behaviour of the anti-environmental consumer. In a survey of 521 consumers, environmental attitude was a poor predictor of environmental behaviour. A series of interviews was performed with different profiles of environmentally orientated users to assess their environmental attitudes and behaviour. The survey and interview data were used to develop four personas, one for each of the environmental attitude and behaviour types based on data from the consumer survey. A case study performed with university design students found that concepts generated by groups using environmentally orientated personas scored higher on environmental sustainability versus those generated by groups using an image board. This study illustrates how user-centred design approaches could be used to embed sustainable design in products by exploiting consumer environmental behaviour to overcome different attitudes and behaviour.

A study of laparoscopic instrument use during colorectal surgery.

The aim of this study was to quantify laparoscopic instrument use and actions of both limbs during a sample of common colorectal surgical procedures. A method was devised using Observer XT software to code video recordings. Anonymised HD video recordings of nine laparoscopic colorectal procedures performed by a single surgeon were analysed. We determined the percentage and frequency of instrument use and limb actions throughout the total laparoscopic surgical duration, as well as the duration of instrument inactivity. Seven instruments and seven actions were studied across nine surgical procedures. Manoeuvring, blunt dissection, and tenting up tissues accounted for the longest amount of total surgical time (non-dominant hand (NDH) 29%, dominant hand (DH) 39%), followed by grasping (NDH 33%, DH 9%), and cauterising (NDH <0.2%, DH 8%). Least time was spent performing other actions such as suction/irrigation (NDH 0.01%, DH 3%) and stapling colorectal tissue (NDH 0.03%, DH 0.5%). The total duration of instrument use and hand actions by the dominant and non-dominant hands were similar overall. However, the frequency of actions performed was lower for the non-dominant hand. This indicates that the non-dominant hand spent more time holding actions than switching between actions, supporting the actions of the dominant hand. These findings highlight the lengthy durations of laparoscopic surgical procedures involved in navigating to anatomical planes and moving tissues. Further, the results detail the extent of secondary functions performed with the surgical instruments.

3D modelling of non-intestinal colorectal anatomy.

PURPOSE: There is a paucity of methods to model soft anatomical tissues. Accurate modelling of these tissues can be difficult with current medical imaging technology. METHODS: The aim of this research was to develop a methodology to model non-intestinal colorectal tissues that are not readily identifiable radiologically to enhance contextual understanding of these tissues and inform medical device design. The models created were used to inform the design of a novel medical device to separate the mesocolon from the retroperitoneum during resection of the colon. We modelled the peritoneum and the mesentery. The mesentery was used to indicate the location of Toldt's fascia. RESULTS: We generated a point cloud dataset using cryosection images as the target anatomy is more visible than in CT or MRI images. The thickness of the mesentery could not be accurately determined as point cloud data do not have thickness. A denser point cloud detailing the mesenteric boundaries could be used to address this. CONCLUSIONS: Expert anatomical and surgical insight and point cloud data modelling methods can be used to model soft tissues. This research enhances the overall understanding of the mesentery and Toldt's fascia in the human specimen which is necessary for medical device innovations for colorectal surgical procedures.

Mechanical characterisation of porcine non-intestinal colorectal tissues for innovation in surgical instrument design.

This article presents an investigation into the mechanical properties of porcine mesocolon, small intestinal mesentery, fascia, and peritoneum tissues to generate a preliminary database of the mechanical characteristics of these tissues as surrogates for human tissue. No study has mechanically characterised porcine tissue correlates of the mesentery and associated structures. The samples were tested to determine the strength, stretch at failure, and stiffness of each tissue. The results indicated that porcine mesenteric and associated tissues visually resembled corresponding human tissues and had similar tactile characteristics, according to an expert colorectal surgeon. Stiffness values ranged from 0.088 MPa to 6.858 MPa across all tissues, with fascia being the weakest, and mesentery and peritoneum being the strongest. Failure stress values ranged from 0.336 MPa to 6.517 MPa, and failure stretch values ranged from 1.766 to 3.176, across all tissues. These mechanical data can serve as reference baseline data upon which future work can expand.

Toward a Model of Human Information Processing for Decision-Making and Skill Acquisition in Laparoscopic Colorectal Surgery.

OBJECTIVE: To create a human information-processing model for laparoscopic surgery based on already established literature and primary research to enhance laparoscopic surgical education in this context. DESIGN: We reviewed the literature for information-processing models most relevant to laparoscopic surgery. Our review highlighted the necessity for a model that accounts for dynamic environments, perception, allocation of attention resources between the actions of both hands of an operator, and skill acquisition and retention. The results of the literature review were augmented through intraoperative observations of 7 colorectal surgical procedures, supported by laparoscopic video analysis of 12 colorectal procedures. RESULTS: The Wickens human information-processing model was selected as the most relevant theoretical model to which we make adaptions for this specific application. We expanded the perception subsystem of the model to involve all aspects of perception during laparoscopic surgery. We extended the decision-making system to include dynamic decision-making to account for case/patient-specific and surgeon-specific deviations. The response subsystem now includes dual-task performance and nontechnical skills, such as intraoperative communication. The memory subsystem is expanded to include skill acquisition and retention. CONCLUSIONS: Surgical decision-making during laparoscopic surgery is the result of a highly complex series of processes influenced not only by the operator's knowledge, but also patient anatomy and interaction with the surgical team. Newer developments in simulation-based education must focus on the theoretically supported elements and events that underpin skill acquisition and affect the cognitive abilities of novice surgeons. The proposed human information-processing model builds on established literature regarding information processing, accounting for a dynamic environment of laparoscopic surgery. This revised model may be used as a foundation for a model describing robotic surgery.

Review of the sustainability of food systems and transition using the Internet of Food.

Many current food systems are unsustainable because they cause significant resource depletion and unacceptable environmental impacts. This problem is so severe, it can be argued that the food eaten today is equivalent to a fossil resource. The transition to sustainable food systems will require many changes but of particular importance will be the harnessing of internet technology, in the form of an 'Internet of Food', which offers the chance to use global resources more efficiently, to stimulate rural livelihoods, to develop systems for resilience and to facilitate responsible governance by means of computation, communication, education and trade without limits of knowledge and access. A brief analysis of the evidence of resource depletion and environmental impact associated with food production and an outline of the limitations of tools like life cycle assessment, which are used to quantify the impact of food products, indicates that the ability to combine data across the whole system from farm to human will be required in order to design sustainable food systems. Developing an Internet of Food, as a precompetitive platform on which business models can be built, much like the internet as we currently know it, will require agreed vocabularies and ontologies to be able to reason and compute across the vast amounts of data that are becoming available. The ability to compute over large amounts of data will change the way the food system is analysed and understood and will permit a transition to sustainable food systems.

An environmental analysis of options for utilising wasted food and food residue.

The potential environmental impact of wasted food minimisation versus its utilisation in a circular bioeconomy is investigated based on a case study of Ireland. The amount of wasted food and food residue (WFFR) produced in 2010 was used for business-as-usual, (a) and four management options were assessed, (b) minimisation, (c) composting, (d) anaerobic digestion and (e) incineration. The environmental impacts Global Warming Potential (GWP), Acidification Potential (AP) and Eutrophication Potential (EP) were considered. A carbon return on investment (CRoI) was calculated for the three processing technologies (c-e). The results showed that a minimisation strategy for wasted food would result in the greatest reduction of all three impacts, -4.5 Mt CO2-e (GWP), -11.4 kt PO43-e (EP) and -43.9 kt SO2-e (AP) compared to business as usual. For WFFR utilisation in the circular bioeconomy, anaerobic digestion resulted in the lowest environmental impact and best CRoI of -0.84 kg CO2-e per Euro. From an economic perspective, for minimisation to be beneficial, 0.15 kg of wasted food would need to be reduced per Euro spent.

The effect of lameness on the environmental performance of milk production by rotational grazing.

Dairy production leads to significant environmental impacts and increased production will only be feasible if the environmental performance at farm level permits a sustainable milk supply. Lameness is believed to become more prevalent and severe as herd sizes increase, and can significantly reduce milk output per cow while not influencing other attributes of the production system. The objective of this work was to quantify the effect of lameness on the environmental performance of a typical grazed grass dairy farm and evaluate the theoretical value of sensor-based real-time lameness management. Life cycle assessment was used to compare a typical baseline farm with scenarios assuming increased lameness severity and prevalence. It was found that lameness could increase the farm level global warming potential, acidification potential, eutrophication potential and fossil fuel depletion by 7-9%. As increased herd sizes will increase cow: handler ratio, this result was interpreted to suggest that the use of sensors and information and communication technology for lameness detection could improve management on dairy farms to reduce the adverse impact on environmental performance that is associated with lameness.