Implementing smart materials and technologies for medical emergency airway access devices

Airway management and intubation procedures continue to challenge anaesthetists daily. Failure to secure the airway with an endotracheal tube in a timely manner upon induction of anaesthesia can lead to serious complications, including death or disability. Most anaesthetists consider endotracheal tube introducers (bougies) as essential equipment; however, there are many different types with relatively little performance data to help anaesthetists make an informed choice. Standard bougies have a requirement to be reshaped multiple times in an attempt to create the desired navigation path of the endotracheal tube. Manoeuvring within the trachea presents significant navigation and control challenges whilst attempting to minimise trauma. Improvements in airway management care is often facilitated by the introduction of new or improved airway management equipment, however understanding their physical properties is imperative for the development of an improved device. This research addresses the development of a new emergency airway access device; the steerable bougie has been designed to enhance device control and improve the speed and the safety of bougie guided endotracheal intubation. Initial work focussed on assessing the case of need for the development of an improved bougie, in addition to identifying design criteria and specifications. A number of anaesthetists were surveyed and identified increased manoeuvrability in-situ, improved shape retention and steerable control as desirable device attributes. Initial design, development and testing explored the feasibility of actuators and smart materials capable of replicating a steerable movement. Initial prototyping and testing demonstrated that flexible steerable tips controlled by Flexinol® actuator wires could effectively control the navigation of the tip. Understanding the physical properties of bougies is fundamental to patient safety, device operation and ultimately equipment procurement decisions. Accurate and reliable bougie safety performance data, including perforation forces, bougie tip pressures and shape retention is not available. Equipment evaluations often fail to consider key testing criteria including testing equipment specifications. Tip pressure studies conducted identified current equipment weaknesses with airway trauma, including significant mucosa damage and perforation easily achieved by low tip pressure forces. The steerable bougie demonstrated significantly lower tip pressure forces compared to commercially available bougies. Repeatability testing conducted assessing tip pressure performance identified variable degradation over time for all commercially available bougies; the developed steerable bougie presented limited degradation over time. Anaesthetists define shape retention as a critical performance characteristic for a bougie. To match the curvature of a patient's airway multiple bougie shaping iterations are usually required, however bougies often return to their original shape within seconds of being manipulated. All bougies present initial snap back and shape loss. To identify bougies with optimal shape retention, an innovative Shape Retention Testing System (SRTS) was designed and built to test shape retention characteristics. Testing demonstrated that bougies with dual or multi-lumened structures provided the highest level of shape retention hold. The steerable bougie outperformed the commercially available bougies at most shaping distances, demonstrating limited shape loss. Utilising the accumulated bougie performance data, a steerable bougie with improved shape retention, reduced tip pressures and reduced likelihood of causing airway trauma has been developed. The steerable bougie is connected to an ergonomically designed controller attached to a laryngoscope that can also be easily attached/detached and sterilised. This research has demonstrated that a steerable bougie with augmented physical properties can be developed that not only provides medical professionals with a device that has increased steerability and usability for time critical procedures but will also reduce the likelihood of patient airway trauma

What airway and vascular access skills can be performed whilst wearing the NHS issued chemical, biological, radiation, and nuclear personal protective equipment?

The introduction of chemical, biological, radiation and nuclear personal protective equipment (CBRN-PPE) across the National Health Service (NHS), in 2007, represented an increase in the capacity to treat patients following a CBRN incident. However, little was known on what impact the NHS CBRN-PPE would have on skill performance. To date a number of studies have evaluated various skills performed whilst wearing a range of CBRN-PPE, none of which resembles the NHS CBRN-PPE. This gap in the evidence prompted a series of research studies addressing the following research question, ‘What airway and vascular access skills can be performed whilst wearing the NHS issued chemical, biological, radiation, and nuclear personal protective equipment? The resulting nine published peer-reviewed papers are presented with a critical commentary in three chapters: Chapter 3 (Papers 1 to 4) assesses what clinical skills can be performed using the NHS CBRN-PPE; Chapter 4 (Papers 5 & 6) explores clinicians’ views on the preferences and experiences of airway management whilst wearing CBRN-PPE; and Chapter 5 (Papers 7 to 9) evaluates the optimal strategies of airway management whilst wearing the NHS CBRN-PPE. Chapter 6 is a summary of the findings presented in this thesis and presents a number of new research questions to further expand our knowledge-base, regarding skill performance whilst wearing NHS CBRN-PPE, reflecting the developmental nature of this area of research. The research contained in this thesis utilises a combination of randomised controlled trials, interviews and questionnaires, to ascertain the impact of the NHS CBRN-PPE on skill completion. Papers 1 to 4 recruited a group of mixed clinicians allowing subgroup analysis observing for inter-professional differences regarding skill performance. Whereas, Papers 7 to 9 recruited student paramedics ensuring similar levels of airway management skills, thereby isolating prior expertise as a variable. The research presented in this thesis has been used during simulation training as part preparations for the 2012 Olympics, in the development of a CBRN training DVD and incorporated into a textbook. The results have also been shared with NHS England working party on CBRN-PPE and, are being incorporated into CBRN treatment protocols by an overseas ambulance service

A Paradigm Shift of Airway Management: The Role of Video-Assisted Intubating Stylet Technique

Difficult or failed intubation is a major contributor to morbidity for patients and to liability for the provider. Research to improve understanding, prevention, and management of such complications remains an anesthetic priority, and a driving force behind continuous improvements in intubation techniques and intubation equipment. The purpose of this review article is to focus on the video-assisted intubating stylet technique (VS; also known as the Shikani optical stylet technique for intubation) and video-assisted optical stylet devices, both for routine use and alternative rescue application for tracheal intubation, and stress their advantages as compared to conventional direct laryngoscopy and videolaryngoscopy. The VS technique was introduced by Dr. Alan Shikani in 1996 and popularized with the advent of the Shikani optical stylet and subsequent similar stylets variations. We focus on the clinical details of the technique itself, and on the various advantages and troubleshooting under different clinical scenarios and practice settings. In our experience, video-assisted intubating stylet technique often constitutes the most appropriate approach both for daily routine and emergency airway management. Furthermore, we also emphasize the importance of video-assisted intubating stylets in enhancing the practitioner systems response when difficult or failed tracheal intubation is encountered

Medical device design within the ISO 13485 framework

The design and development of medical devices has become an increasing complex and regulated process. Little if any consideration is given to the regulatory requirements when developing medical devices in universities. This has resulted in an imposing barrier preventing academic innovation reaching clinical adoption. The scope of universities is not to become the legal manufacturer of medical devices. However, should the development of novel devices ever aim to benefit patient care and reach a clinical setting, design controls must be implemented throughout the project life cycle to demonstrate feasibility and safety. The aim of this thesis is to develop user-centred technologies which comply with industrial design control practices whilst helping to bolster and promote innovation within academia. Four projects relating to medical devices have been designed in response to well-defined and end-user-originated clinical needs. These devices can serve as the exemplar for the framework developed in this work with each reaching staggered phases of development within a controlled design process. Although unique, the devices have significant overlapping characteristics that lend the devices to parallel development, leveraging in-house know-how and ‘lessons learned’ into the process of innovation. This thesis focuses on the novelty and design of the aforementioned projects in a discrete structured approach and reflects on the development of each project within the context of a design control process which was developed as part of this work. It is the ultimate goal of this work to develop a flexible structured system compliant with the international requirements for product design and development which may be exported internationally. However, the full execution of this ambition was limited due physical, and financial limitations. This manuscript will describe the technical and commercial opportunity of devices and reflects on the success of developing same within a design control process developed as part of this work