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.

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.