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Beth Chadburn

Ergonomics and Human Factors MSc

I am a product designer who turned to ergonomics and human factors because of a passion for human interaction with objects and systems with a keen interest in medical device design.

Final Project

The operating height and anthropometric size affect on the physical discomfort of females using laparoscopic instruments.

Research Question:

‘Do bed height and anthropometric size affect the physical discomfort in the hands, wrists, and elbows, of females using laparoscopic instruments and carrying out surgical tasks?’. 

Background

As the diversity of practising surgeons is increasing, there is a growing need for inclusive laparoscopic instruments and ergonomic practices (Mesiti, 2023). Often female laparoscopic surgeons experience higher rates of MSDs and chronic pain linked to surgical procedures and instrument design (Hislop, 2023). Limitations of operating room design for female surgeons, such as table height range and laparoscopic instrument design, mean they must adapt techniques to achieve the desired outcomes. Consequently, the inadequate design forces surgeons to use high-risk postures that are held for extended periods or frequently repeated over the procedure inducing MSDs (Sánchez-Margallo, 2017).

Objectives

The objectives of this research are to:

Methods

& Results


Female participants (n=14) were used for a simulation study using training laparoscopic instruments, an adjustable height hospital bed, and a peg board task. A high and low bed height condition was used to assess the discomfort between variables. Data was collected from participants’ joint angles, discomfort ratings and anthropometric measurements, which were used to investigate the hypotheses:
H1 The use of laparoscopic instruments at different bed heights will cause a difference in discomfort or joint angles for female participants in elbows and wrists.
H2 The anthropometric measurements of an individual using laparoscopic instruments will cause a difference in discomfort.
The results of the research found a significance in the difference between discomfort ratings and bed height, with a relationship found that high bed height (HBH) induces greater discomfort ratings than low bed height (LBH). A significant difference was also found between the measured joint angles and bed height. A relationship was found with left and right elbow joint angles being more acute in flexion at HBHs, compared to LBHs where angles of flexion were larger. Participants with smaller index fingers, middle fingers and handbreadth experienced a significantly higher rate of discomfort at the HBH.

Conclusion

The research found that the operating height of female surgeons carrying out laparoscopic procedures influences the discomfort experienced. The lack of anthropometric variability in the design of operating table height and laparoscopic instruments causes an increased risk of MSDs for female surgeons, who are more likely to have a shorter stature and smaller hand size. The accumulation of high bed height and laparoscopic instrument design exacerbates the discomfort experienced by female surgeons who must perform awkward postural movements for surgical tasks. These adaptations some female surgeons use to perform surgery are unsatisfactory ergonomic solutions. Therefore, alterations to operating room equipment in laparoscopic surgery should include a wider range of adjustable operating heights for shorter stature. The design of laparoscopic instruments should focus on adaptability for various anthropometric measurements principally, the index-finger, the middle-finger and the handbreadth.

Other work

Healthcare Systems and Patient Safety:
The system of diagnosis of endometriosis patients within the UK has issues in awareness, support, and resources that impact the ability to timely diagnose patients. The diagnosis of endometriosis is a long and complex process involving multiple individuals and tasks to diagnose and later manage the condition. Systems analysis and models were used to understand the work system in place for the diagnosis of endometriosis, and to provide findings and insights into barriers, facilitators, interactions, quality, and the level of resilience within the system. The models used were SIEPS, STAMP, Swim Lane diagrams and PETT tables. The systems analysis found weaknesses in; the awareness of health professionals and patients, medical gender bias, comorbidity of the condition hindering diagnosis, and lack of legislative action. Recommendations for improvement were made to drive down the waiting times and improve the general experience of diagnosis for patients.

Inclusive Design:
A semi-rural rail service was evaluated for inclusive design aspects of accessibility and usability for elderly users. The consideration of elderly users can help provide benefits for all possible users with a range of needs during the design process of rail services.  A persona, service safari, and expert appraisal checklist were used in the evaluation of rail services. It included the schedule information, the ticket procurement, the platforms, the station, the train, and the journey. The results found a need to introduce more inclusive design and organisational changes such as more staff to improve rail services for elderly users and other excluded groups of people. This is crucial to rural and semi-rural rail services where less accessibility and staff are present and social exclusion to elderly users is more prominent.


Human Factors and Systems:
A human factors systems analysis of accidents and the aggregation of the medical radiation overdoses by the Therac-25 were important to understand the broader picture of how these accidents occur. Systems analysis and models (accimap and FRAM) were used to understand how the accidents of the Therac-25 occurred within the work system and to provide findings for insights into the hierarchal causal links, factors and the level of resilience within the system. The systems analysis found the Therac-25 accidents were caused by a multitude of factors within a complex socio-technical system including, hardware, software and organisational weaknesses where no single cause can be attributed to the accidents. Multiple recommendations were made focusing on the development of software analysis and testing, user testing, defensive design, and organisational review. This emphasised the importance of human factors and systems intervention during the design and testing of medical devices.


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