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

Monitoring and alleviating the effects of pressure related injuries for spinal surgery–a need for improvement?

The development of pressure injuries (PIs) is a common complication arising during surgery. Monitoring and alleviating PIs is currently not possible during lengthy spinal and orthopaedic surgeries, especially if a patient requires x-rays. We interviewed surgical staff to gain an understanding of attitudes regarding current methods and approaches for the management of PIs to allow the development of new devices based on staff feedback. Interviewees provided insights regarding the possible design of a new device used to monitor and alleviate pressure injuries in a surgical environment. From the interviews we derived key themes, including current devices/systems, current risk assessment/scales, and design considerations. As a result, we identified critical design requirements and an appropriate product design specification. Background: Complications can arise when perioperative staff are monitoring a patient’s health status during surgery, including the development of pressure injuries (PIs). It is important to reduce the incidence rates of developing PIs intraoperatively, and thereby mitigate both increased costs and negative impacts to patients and care providers. Current pressure relief supports offer limited monitoring abilities throughout the perioperative environment. Aim: The aim of this study is to establish clear design requirements and a product design specification that enables a new closed-loop product solution to be developed with real-time pressure monitoring during surgery. Method: We conducted semi-structured interviews with nine different clinical staff members involved in the perioperative environment. We conducted the interviews over a two-week period with two major teaching hospitals within the East Midlands, UK. Questions focused on healthcare professionals’ perceptions of current methods and their approaches to managing PIs. We recorded and transcribed participants’ data using NVivo software. Conclusion: The interview data identified a need for an improved method to manage and monitor PIs. We established that the incorporation of live feedback to reduce the prevalence of PIs is a critical design priority. Based on the interviews, we developed design criteria and a product design specification (PDS). Interview transcripts suggest a new device design should focus on a novel radiolucent pressure redistribution solution capable of reducing PIs intraoperatively while incorporating live feedback

The development of a novel steerable bougie to assist in airway management

Background: This paper describes the development of a new airway device that will improve the speed and safety of endotracheal intubation in anaesthesia and critical care. Case of need, design specification and fabrication of the steerable bougie mechanism is discussed. Aims: Identify the need for a novel steerable bougie whilst considering technology readiness levels associated with medical device design. Analyse and produce suitable mechanisms utilising smart materials to increase device functionality aiding successful patient intubation procedures. Methods: This work describes the total design activity that contributes to the successful development of medical devices, from case of need, to smart material actuation mechanisms. Research focuses on identifying a suitable control mechanism to allow a steerable tip to be integrated into a bougie with a control device attached to the laryngoscope. Results: Data collected from a user group survey supported the development of a novel bougie, with better shape retention, variable rigidity within the tip, and an integrated steerable function. Analysis of several mechanisms, artificial muscles, and smart materials identified a cost-effective steerable mechanism that can be incorporated into a bougie. Conclusion: Users have defined a need for an improved bougie. Controlling smart materials and mechanisms, within the predefined dimensions, identified strengths and weaknesses associated with steerable functions. The performance of the selected mechanism for incorporation requires a high level of control to accurately steer a device within the human airway

Democratic manufacturing: a student manufactured and operated 3D printer farm

The DIY movement goes back to the late 60’s and started the trend of shared tools as a reaction to the lack of skills and education on how things are made; this resulted in an increased awareness of democratic manufacturing resources and facilities, especially makerspaces and hackspaces, innovation labs, 3D printer farms etc. At Nottingham Trent University (NTU), we have observed an increase in students choosing to study Product Design thus increasing pressure on workshop/manufacturing spaces, especially automated manufacturing resources such as 3D Printers. Subsequently, the maker experiences students have been experiencing within the workshop environment temporarily lessened to ensure the needs of our rapidly increasing student cohorts are catered for. This paper explores how democratic technologies and manufacturing tools have overcome this issue by enabling designers, makers, and hobbyists to increase their access to facilities within the Product Design Department at NTU. This paper explores/reflects on the initial development of a 3D printer farm located in a product design studio where a group of sixty-nine students manufactured/assembled eighteen Creality CR-10S 3D printers. The success of the initial student led democratic manufacturing project resulted in ADBE developing a second 3D printer farm in a second product design studio consisting of a further eight Creality CR-10S V3 3D printers. The 3D printer farms are now complimented by a blended induction allowing for student independent use of the resource. Student feedback is also presented regarding the blended induction to ascertain knowledge acquisition and confidence on using the resources independently

Proof-of-concept study: a mobile application to derive clinical outcome measures from expression and speech for mental health status evaluation

This proof-of-concept study aimed to assess the ability of a mobile application and cloud analytics software solution to extract facial expression information from participant selfie videos. This is one component of a solution aimed at extracting possible health outcome measures based on expression, voice acoustics and speech sentiment from video diary data provided by patients. Forty healthy volunteers viewed 21 validated images from the International Affective Picture System database through a mobile app which simultaneously captured video footage of their face using the selfie camera. Images were intended to be associated with the following emotional responses: anger, disgust, sadness, contempt, fear, surprise and happiness. Both valence and arousal scores estimated from the video footage associated with each image were adequate predictors of the IAPS image scores (p < 0.001 and p = 0.04 respectively). 12.2% of images were categorised as containing a positive expression response in line with the target expression; with happiness and sadness responses providing the greatest frequency of responders: 41.0% and 21.4% respectively. 71.2% of images were associated with no change in expression. This proof-of-concept study provides early encouraging findings that changes in facial expression can be detected when they exist. Combined with voice acoustical measures and speech sentiment analysis, this may lead to novel measures of health status in patients using a video diary in indications including depression, schizophrenia, autism spectrum disorder and PTSD amongst other conditions

Development of a PPE visor for female healthcare workers

During the COVID-19 pandemic the demand for personal protective equipment (PPE) has increased dramatically. However, the lack of PPE designed specifically for women is leaving many without adequate protection, as current “universal” solutions fail to address female healthcare workers’ varied needs. Instead, current solutions present users with a host of problems, including discomfort, hindrance, incompatibility with other wearable items, and adjustment difficulties. This paper explores and reflects upon the design thinking approach used to develop a PPE visor for female healthcare workers while following a user-centred design approach/methodology

Usability assessment of facial tracking for use in clinical outcomes

There is an ever-growing body of facial tracking assessment applications available within the health and wellness sector. One of the most prominent areas is the use of 3D cameras and processing technologies in the development of rehabilitation interventions and in the measurement of health outcomes. Recent advancements in facial tracking applications within mobile platforms and cloud computing analytics suggests that new clinical assessment and human computer assessment technologies have significant future potential for pervasive in-clinic and field-based health assessment solutions. This paper reviews the technical capabilities of three facial tracking platforms with a focus on the common issues relating to clinical measurement considerations required for patient-facing systems. Key factors are assessed in relation to 3D camera platforms, mobile applications and cloud computing applications including camera position, lighting and shadows, eye detection and common obstructions or features that affect tracking. Published examples of fcial tracking clinical and health wellness applications are presented in relation to human computer interaction interfaces. This paper aims to demonstrate the potential for future applications being developed relating to each of these technologies for clinic-based applications

Postable peak flow meters: improving remote patient monitoring from the home

As healthcare providers globally adapt/change their practices because of the ongoing global pandemic, a greater emphasis is being placed on remote/telemedicine diagnostic/monitoring models. To support such a model, especially for respiratory diseases-ie, asthma, chronic obstructive pulmonary disease (COPD), or interstitial lung disease (ILD)-it is essential that data are collected over a sustained time period. As such, the distribution of portable medical devices to patients' homes poses a significant logistical challenge. We present the user-centred design approach undertaken by a multidisciplinary design team consisting of product designers, design engineers, electronics/programming experts, and healthcare professionals to develop a postable modular peak flow meter

Mechanical performance assessment system for endotracheal tube introducers using motion detection and object tracking

Failure to secure the airway with an endotracheal tube in a timely manner on induction of anaesthesia can lead to serious complications, including death. Equipment design and selection can often contribute to procedure success or failure, although current equipment does not always provide optimum solutions. Most anaesthetists consider endotracheal tube introducers (bougies) essential equipment; however, there are many different types available, with little relative performance data to inform choice. To date, no performance assessment system exists that is capable of assessing the shape retention properties of bougies. This paper discusses the design development process of the Shape Retention Testing System (SRTS) that utilises motion detection, object tracking and image processing to assess the relative performance of bougie introducers

Performance analysis system for endotracheal tube introducers: standardising for success

Equipment design and selection can contribute to the success or failure of difficult airway management. The design of medical devices/testing systems completed by multidisciplinary design teams that include healthcare professionals can significantly influence device success or failure. This paper presents an overview of the design tasks used to develop the Shape Retention Testing System (SRTS) for the assessment of bougie introducers. By using a multidisciplinary design team that includes healthcare professionals, critical design tasks such as design criteria generation, product design specification (PDS) generation, focused design approaches, and iterative design processes have ensured essential feedback is collected to influence the SRTS’s design and manufacture