Medicine, Faculty of
Medicine, Department of
DSpace
UBCV
Mashat, Abdullah
Master of Science - MSc
University of British Columbia
Within the dynamic and high-stakes environment of the operating room (OR), the inadvertent dropping of surgical instruments represents a notable challenge, with implications for procedural efficiency, patient safety, and overall healthcare costs. Studies have shown that instruments get dropped at significant rate and up to 60% of the cases. Current solutions that have shown to be effective in decreasing the rate of fall, such as magnetic drapes, have limitations, particularly with their inability to support non-metallic instruments. This thesis addresses this gap by designing, developing and evaluating a magnetic retention system that can decrease the rate of fall of nonmetallic instruments. Through an iterative process, the study developed small magnetic clips that can be mounted to non-metallic instruments and allow them to be compatible with the conventional magnetic drapes. To evaluate the new system’s effectiveness, an accelerated testing model was developed and tested in a simulated OR environment, where surgical residents were recruited to preform simulated surgical procedures using the magnetic retention system. The experimental results demonstrated a significant reduction in instrument falls when using the magnetic retention system. Without the system, the mean number of falls was 7.57 per session, while with the system, the mean number of falls dropped to 0.86 per session, p-value <0.05. Additionally, overall performance scores and task completion rates were higher when the magnetic system was used. This thesis contributes to ongoing efforts aimed to improve surgical efficiency and reducing surgical waste, by addressing the challenges associated with instrument falls in OR. The next steps include refining the magnetic retention system, and preparing for clinical trials to move toward commercialization.
Design and Evaluation of a Device to Prevent Instrument Drops During Surgery by Abdullah Mashat MBBS, University of King AbdulAziz University, 2018 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in The Faculty of Graduate and Postdoctoral Studies (Experimental Medicine) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) September 2024 © Abdullah Mashat, 2024 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Design and Evaluation of a Device To Prevent Instrument Drops During Surgery submitted by Abdullah Mashat in partial fulfillment of the requirements for the degree of Master of Science in Experimental Medicine Examining Committee: Dr. Alice Mui, Associate Professor, Department of Surgery, UBC Supervisor Dr. Antony Hodgson, Professor, Department of Mechanical Engineering, UBC Co-Supervisor Dr. Harvey Hawes, Clinical Instructor, Department of Surgery, UBC Supervisory Committee Member Dr. Morad Hameed, Professor, Department of Surgery, Stanford University Supervisory Committee Member Dr. Jeffrey Potter, Clinical Associate Professor, Department of Surgery, UBC Additional Examiner iii Abstract Within the dynamic and high-stakes environment of the operating room (OR), the inadvertent dropping of surgical instruments represents a notable challenge, with implications for procedural efficiency, patient safety, and overall healthcare costs. Studies have shown that instruments get dropped at significant rate and up to 60% of the cases. Current solutions that have shown to be effective in decreasing the rate of fall, such as magnetic drapes, have limitations, particularly with their inability to support non-metallic instruments. This thesis addresses this gap by designing, developing and evaluating a magnetic retention system that can decrease the rate of fall of nonmetallic instruments. Through an iterative process, the study developed small magnetic clips that can be mounted to non-metallic instruments and allow them to be compatible with the conventional magnetic drapes. To evaluate the new system’s effectiveness, an accelerated testing model was developed and tested in a simulated OR environment, where surgical residents were recruited to preform simulated surgical procedures using the magnetic retention system. The experimental results demonstrated a significant reduction in instrument falls when using the magnetic retention system. Without the system, the mean number of falls was 7.57 per session, while with the system, the mean number of falls dropped to 0.86 per session, p-value <0.05. Additionally, overall performance scores and task completion rates were higher when the magnetic system was used. This thesis contributes to ongoing efforts aimed to improve surgical efficiency and reducing surgical waste, by addressing the challenges associated with instrument falls in OR. The next steps include refining the magnetic retention system, and preparing for clinical trials to move toward commercialization. iv Lay Summary In surgery, preventing the accidental dropping of instruments is important as drops can cause delays, increase costs, and even put patients at risk. Currently, tools such as magnetic drapes, which help secure instruments during the procedure and prevent them from falling, do not work on non-metallic surgical tools, such as those used for cutting and sealing tissue. This research works aims to fill this gap and develop a method an innovative magnetic system designed decrease the incidents of non-metallic surgical instrument drop during surgery. After testing in a simulated operating room, the new system was able to significantly reduce the number of dropped instruments, offering a practical solution to improve surgical safety and efficiency. v Preface This thesis is an original piece of work by the author, Abdullah Mashat. The original concept of magnetic clips to prevent the fall non-metallic surgical instruments was initially developed by a team during Surgical Innovation Week 2022 at the University of British Columbia (UBC). The team members were Abdullah Mashat, Claire Liu, and Sorush Rokui and Luke MacLean. No part of this thesis has been previously published. The research was conducted following approval obtained from the UBC Clinical Research Ethics Board (UBC CREB Number: H24-01189). vi Table of Contents Abstract ................................................................................................................................. iii Lay Summary ......................................................................................................................... iv Preface ................................................................................................................................... v Table of Contents ................................................................................................................... vi List of Tables .......................................................................................................................... ix List of Figures .......................................................................................................................... x List of Abbreviations ............................................................................................................. xii Acknowledgements .............................................................................................................. xiii Chapter 1: Introduction ........................................................................................................... 1 1.1 Evidence of instrument fall, causes in the operating room: .................................................. 1 1.2 Impact of instrument falls on the health care system: ......................................................... 3 1.3 Currently Available Solutions: .............................................................................................. 5 1.4 Magnetic Drapes and Gap of research: ................................................................................ 7 1.5 Proposed Solution and Thesis Goal: Device Design, and Verification: ................................... 9 1.6 Thesis Outline ...................................................................................................................... 9 Chapter 2: Device Design ...................................................................................................... 10 2.1 Initial Design Consideration (Requirements): ..................................................................... 10 2.1.1 Functional Requirements: ................................................................................................................... 10 vii 2.1.2 Non-Functional Requirements: ........................................................................................................... 11 2.2 Concepts: .......................................................................................................................... 12 2.2.1 Project Inception: ................................................................................................................................ 12 2.2.2 Early Prototypes: ................................................................................................................................. 14 2.3 Developments ................................................................................................................... 15 2.3.1 Iterative Refinement ........................................................................................................................... 15 2.3.2 Final Design: ........................................................................................................................................ 17 2.3.3 Holding station .................................................................................................................................... 21 Chapter 3: Verification Methodology .................................................................................... 24 3.1 Challenges in Testing and Rationale for Accelerated Failure Model .................................... 24 3.2 Study Design: .................................................................................................................... 25 3.3 Operating Table Design Setup: ........................................................................................... 26 3.4 Simulation Procedure ........................................................................................................ 29 3.5 Performance Scoring and Evaluation: ................................................................................ 30 3.6 Data Collection and Analysis .............................................................................................. 32 3.7 Ethical Consideration ......................................................................................................... 32 Chapter 4: Verification Results .............................................................................................. 34 Chapter 5: Discussion: ........................................................................................................... 42 5.1 Research Questions: .......................................................................................................... 42 5.2 Relation to Other Literature .............................................................................................. 44 viii 5.3 Limitations: ....................................................................................................................... 46 5.4 Recommendations and Future Work: ................................................................................ 48 5.5 Conclusion: ........................................................................................................................ 50 Bibliography ......................................................................................................................... 51 Appendices ........................................................................................................................... 59 Appendix A : Post-simulation questionnaire .................................................................................. 59 Appendix B : Participant consent forms ......................................................................................... 63 ix List of Tables Table 1 - Task Completion Scoring .............................................................................................. 31 Table 2 - Transition Time Scoring ................................................................................................ 31 Table 3 - Participant demographics .............................................................................................. 34 Table 4 - Summary of Instrument Falls with and without the Magnetic Attachment System, showing a marked reduction in falls when the system is used. .................................................... 36 Table 5 - Paired t-Test Results ...................................................................................................... 36 Table 6 - Effect Size (Cohen's d) .................................................................................................. 37 x List of Figures Figure 1 - Disposable drapes with built-in instrument pouches ..................................................... 6 Figure 2 Surgical magnetic drape ................................................................................................... 8 Figure 3 - Early prototype during SIW ......................................................................................... 14 Figure 4 - Off-the-shelf rachet hose clamp ................................................................................... 15 Figure 5 - Rachet clamp with circumferential magnets ................................................................ 16 Figure 6 - Application of the rachet magnetic clip on a surgical cautery tool device .................. 17 Figure 7 - CAD schematic of the L-shaped design of the magnetic clip ...................................... 19 Figure 8 - Application of L-shaped magnetic clip on a monopolar cautery tool device .............. 20 Figure 9 - Magnetic docking station for securing the cautery tool, featuring a metallic surface with embedded magnets and a curved artery forceps for attachment to patient drapes. .............. 22 Figure 10 - Docking station securing a cautery tool equipped with a magnetic clip at a steep angle .............................................................................................................................................. 23 Figure 11 - Inside of the surgical simulation model showing different training exercises ........... 27 Figure 12 – Simulated OR setup with the magnetic retention system in place, including the docking station for the cautery tool and a magnetic drape on the left for the rest of the instruments. ................................................................................................................................... 28 Figure 13 - Flowchart showing the sequence of surgical tasks participants go through during each session, this included solving mazed on an iPad screen using an apple pencil attach to the ........ 30 Figure 14 - Clustered bar chart illustrating the comparison of instrument falls with and without the Magnetic Attachment System across participants. ................................................................. 35 xi Figure 15 - Side-by-side box plot showing the reduction in instrument falls with and without the magnetic attachment system. Bold line = median; box length = interquartile range (IQR); error bars = range; circle = outlier. ........................................................................................................ 37 Figure 16 - Clustered bar chart illustrating the mean number of falls for non-metallic instruments with and without the magnetic retention system. .......................................................................... 38 Figure 17 - Clustered bar chart comparing mean total performance scores between control and magnetic conditions across participant. Panel A represents the control condition, and panel B represents the magnetic condition ................................................................................................. 39 Figure 18 - Mean scores for key usability aspects of the magnetic retention system. Participants rated each item using a 5-point Likert scale, with higher scores indicating stronger agreement. 41 xii List of Abbreviations CAD – Computer-Aided Design CASMART – Centre for Aging SMART OR – Operating room PGY – Post graduate year SD – Standard deviation SIW – Surgical Innovation Week SSI – Surgical site infection xiii Acknowledgements First and foremost, I would like to express my deepest gratitude to my supervisors, Dr. Alice Mui and Dr. Tony Hodgson for their invaluable guidance, expertise, and unwavering support throughout this project. I also extend my sincere thanks to Dr. Harvey Hawes and Dr. Morad Hameed, for their supervision and insights, which greatly enriched this work. My heartfelt gratitude goes to my parents, who turn my ambitions into reality. My mother’s abundant love has been a constant source of comfort and strength, and my father, my role model growing up, set the standard for perseverance and integrity that I strive to meet every day. To my wonderful wife, who stood by me through many challenges, I owe a special thanks for her unwavering love and support. I am thankful to UBC Surgical Innovation Week program and my team members, Claire Liu, Sorush Rokui, and Luke MacLean, whose collaboration sparked the conceptualization of this project. Additionally, I would also like to acknowledge the Center for Aging SMART at Vancouver General Hospital for providing the space and resources essential for this research. Lastly, and most importantly, my deepest gratitude and praise to God, whose countless blessings and guidance have continually opened doors for me throughout my journey, bringing me to where I am today. 1 Chapter 1: Introduction 1.1 Evidence of instrument fall, causes in the operating room: The operating room (OR) is a unique place in hospitals, where harmony and collaboration must exist between surgeons, assistants, and scrub nurses occurs within a confined yet dynamic space, handling delicate instruments essential for patient care. This intricate environment, detailed by Lingard (2004), is characterized by a multidisciplinary team of surgeons, residents, nurses, anesthesiologists and even medical students, each playing a unique role that is vital for comprehensive perioperative care (Watkins, 2023). With the increase in the complexity of surgical procedures and patients’ needs, OR teams face growing challenges when it comes to optimizing efficiency while still maintaining high-quality care and cost-effectiveness (Fong, 2016; Wakeman, 2018). The presence of such a diverse team can increase the likelihood of communication breakdowns or coordination errors, both of which can contribute to the mishandling of instruments and an increased rate of instrument falls. Despite meticulous attention to detail, instrument falls remain a persistent issue that can significantly disrupt surgical procedures. A few studies have systematically studied the rate of instrument falls in the OR, revealing that these incidents are more common than one might expect. In a prospective study lasting 18 months and observing 120 major orthopaedic surgeries, Khan (2008) reported that the rates of instrument falls were 38.5% during elective surgeries and 61.5% during emergency surgeries. These rates were similar to those found by Joshi (2012), who conducted a similar 24-month prospective study observing 362 caesarean section surgeries, 2 which revealed that instruments fell at a rate of 18.4% and 56.5% in elective and emergency cases, respectively. The reasons why surgical instrument falls in the OR are complicated and multifaceted. As Khan (2008) and Joshi (2012) have shown, instrument falls occur more frequently and at an earlier stage in emergency cases than elective ones. Also, the initial fall of an instrument has been found to occur at around 1.5-2 hours after the start of surgery, which made some believe that it may be associated with surgeon’s fatigue (Khan, 2008; Dorion, 2013). Additionally, surgeon’s procedural habits can also play a role – tools that are kept within easy reach but outside the primary surgical field are more prone to being accidentally knocked over or dropped (Sedigh et al., 2019). Communication errors among the surgical team further exacerbate the issue, especially those related to instrument handling between the scrub nurse and surgeon. Halverson et al. (2011) noted that misinterpretations during these critical exchanges are common contributors to instrument drops. Lastly, patient position and procedures in the abdominal cavity are associated with more risk of instrument falls, due to the challenging angles and positions required during these surgeries (Sedigh et al., 2019). In the context of this thesis, it is important to distinguish between the term “fall” and “drop”. According to the Oxford English Dictionary, "drop" is defined as “to let or make (something) fall vertically” and "fall" as “to descend freely by the force of gravity” (Oxford English Dictionary, 2024). We have defined “drop” as an event where an instrument is unintentionally released by 3 the user during handling or passing, and “fall” as an event where an instrument, after being placed on a surface, slides off the operating table. For both drops and falls, the critical criterion is that the instrument reaches the ground, descends below the sterile zone, or falls to the level of the waist. This thesis captures and examines both drops and falls, and the terms will be used interchangeably throughout the thesis. 1.2 Impact of instrument falls on the health care system: The consequences of instrument falls in the OR are far-reaching, and can affect surgical efficiency, safety, and overall healthcare costs. Khan (2008) explains how there can be immediate repercussions that range from increased embarrassment to surgical staff, prolonging operating times, waste of resources by needing to sterilize or replace the fallen instrument, and potentially compromising patient care. Each incident can disrupt the surgical flow, leading to delays that can prolong the duration of the surgical procedure. Joshi et al. (2012) reported that instrument falls can cause an average delay of 5.7 minutes for each incident, which can accumulate across multiple surgeries and multiple incidents of instrument drop, which can significantly impact OR scheduling and resource allocation. ORs are one of the most resource-intensive environments in the healthcare system, and is the second most expensive portion of surgical care (Stey et al., 2015). These costs arise from several factors, such as salaries for surgical staff, use of equipment and instruments, anesthesia, electricity and consumption of disposable supplies. These financial burdens are further 4 exacerbated by delays caused by instrument drops. Multiple studies have looked into OR costs, and have reported a range of costs per minute of $26-36 (Childers et al., 2018; Grossi et al., 2015; Lee et al., 2019). These drops can potentially have significant financial implications. Consider the case of British Columbia, where more than 350,000 surgeries are performed annually (British Columbia Ministry of Health, 2023). Since the rate of instrument drops likely ranges from ~30-60%, depending on the case acuity, and if each incident causes an average delay of about 5 minutes, the cumulative cost could reach millions of dollars each year. For instance, if we take a 30% drop rate per procedure as a possibly conservative estimate, the annual delay cost alone could potentially exceed $6M in British Columbia. With over 50 million surgeries performed annually in North America, the opportunity to reduce these incidents represents a compelling case for reducing the cost of health care (Dobson, 2020). Beyond operational delays, the need to re-sterilize or replace fallen instruments introduces additional costs. These costs are not limited to the instruments themselves but include the resources and time needed for re-sterilization. Particularly concerning are non-metallic instruments such as LigaSure devices, harmonic scalpels, and cautery monopolar pen, which are critical in modern surgeries. These devices are often single-use, and their single-use cost ranges from around $30 for a cautery pen up to $2000 for instruments such as harmonic scalpels or powered bowel staplers (Suh et al., 2021; Agarwal et al., 2020; CIA Medical, n.d.; Tiger Medical, n.d.). In recent years, the use of these single-use energy devices has been on the rise, driven by technological advancements in surgical instruments (Olasehinde et al., 2022; Homma, 5 2022). Given the associated high cost and the frequency of use, minimizing the risk of falls for these devices can lead to substantial cost savings within the OR. Moreover, this can also have effects on patients’ safety as unnecessary prolongation of surgery time can put the patients at increased risk of developing surgical site infections (SSI) (Vautrin, 2019; Cheng et al., 2017; Peersman et al., 2006; Procter et al., 2010). Studies have found that the likelihood of SSI can increase by approximately 13%-17% for 15-30 minute extensions of surgery time (Cheng et al., 2017). This increase in SSI not only affects patients’ safety but also has significant financial implications on the health care system, with costs ranging from C$20,000 up to C$50,000 per incidence of SSI (Petrosyan et al., 2021). 1.3 Currently Available Solutions: Several strategies are being used to mitigate the risk of instrument falls in the OR. Traditional approaches focus on improving the organization and handling of instruments and targeted teaching have been described (Jain, 2021). Furthermore, disposable drapes with built-in instrument pouches, as shown in Figure 1, are another method some have utilized due to its ability to store tools. Another simple yet important technique is concentrating on a seamless transfer of instruments between surgeons and scrub nurses, which addresses the precision required for handling microsurgical instruments (Joshi, 2012; Greenberg, 1981). 6 Figure 1 - Disposable drapes with built-in instrument pouches Despite these efforts, the existing solutions still exhibit several limitations. For instance, the effectiveness of the drape pouches is limited by its size and capacity to only accommodate smaller instruments, leaving larger tools still prone to falls (Jain, 2021). Additionally, while behavioural factors and organization of tool placement and handling should be emphasized, these practices rely heavily on individual compliance and can be compromised by the fast-paced, high-pressure environment of the OR (Whalan, 2009; Osborne, 1999). This could also explain why instrument fall rates increase during emergency cases. 7 1.4 Magnetic Drapes and Gap of research: One promising solution for reducing the incidents of instrument fall in the OR is the use of magnetic drapes. These drapes have magnets embedded into them which can securely hold metallic instruments in place once they are placed onto it, and prevents them from slipping off the operating table, as shown in Figure 2. Research has demonstrated their effectiveness, showing a significant reduction in instrument falls when magnetic drapes are used. Sedigh et al. (2019) conducted a prospective study that looked into the effect of incorporating magnetic drapes in the OR and reported that the rate of instrument fall decreased from 55% to 19% during surgeries that utilized magnetic drapes. Moreover, magnetic technologies have been used in the OR for other reasons, such as in needle magnets as noted by Rahmati (2014), that can be used to minimize sharps injuries. 8 Figure 2 Surgical magnetic drape While implementing magnetic drapes represents a promising solution to reduce the risk of instrument falls in the OR, a significant research gap exists regarding their applicability to non-metallic instruments. Magnetic drapes are limited to metallic instruments making many new surgical technologies, especially energy devices such as monopolar cautery tool, harmonic scalpels, and bipolar vessel sealing devices incompatible with it. These instruments not only represent a significantly higher cost to healthcare providers due to their expense and single-use nature but also pose a significant challenge in the OR when they fall, requiring longer times to be 9 discarded and replaced and potentially disrupting surgical flow (Suh et al., 2021; Agarwal et al., 2020). 1.5 Proposed Solution and Thesis Goal: Device Design, and Verification: The purpose of the work described in this thesis, therefore, was to design, build, and evaluate a prototype of a magnetic retention system specifically aimed at preventing the fall of non-metallic surgical instruments. The scope of this thesis includes both the design and fabrication of the prototype, as well as its verification through testing. The thesis aimed to answer the following question: Can we develop a prototype device intended to reduce the rate of falls of non-metallic surgical instruments and provide sufficient evidence of its expected performance to justify refining it for use in clinical practice? 1.6 Thesis Outline The remainder of this thesis is organized as follows: • Chapter 2: Device Design • Chapter 3: Verification Methodology • Chapter 4: Verification Results • Chapter 5: Discussion and Future Work 10 Chapter 2: Device Design This chapter details the conceptualization, development and refinement of the magnetic retention system that is designed for non-metallic surgical instruments. The chapter first begins with the design requirements and how the iterative design process led to the final prototype design. 2.1 Initial Design Consideration (Requirements): 2.1.1 Functional Requirements: Several functional and non-functional design requirements were selected for designing a system that would decrease the rate of fall in non-metallic surgical instruments so as to ensure that it is both effective and safe at decreasing the rate of fall of surgical instruments. First, several functional design requirements were selected for the solution to have, which include the following: - Secure attachment: The device must be able to securely hold non-metallic surgical instruments such as monopolar cautery tool tools at various angles during surgical procedures. The magnetic force should be strong enough to hold the weight of the instruments but at the same time allow for easy detachment by the surgical team. - Compatibility: The device should be compatible with common non-metallic instruments such as monopolar cautery tool, plastic suction, or other tools. It also should make non-metallic instruments be able to attach to regular magnetic drapes. - Non-interference: The attachments to the non-metallic instruments should not interfere with the normal operation, handling, or grip of the instruments. 11 - Ease of Use/implementation: The use of the device should be easy and intuitive, designed for quick and straightforward attachment, minimizing time and knowledge required for setup by the surgical staff at the beginning of the case. - Prevention of Device Dislodgement: The design must incorporate features that would prevent the accidental device detachment and falling into the surgical field or inside a patient cavity. - Consideration for Tethered Instruments: Instruments such as cautery and suction are often tethered by cables or tubes, which can add additional weight and torque, making them potentially more prone to fall. As such, the design must ensure that the attachment can handle the loads associated with these tethered instruments. 2.1.2 Non-Functional Requirements: In addition to functional requirements, several non-functional requirements were identified. These requirements focused on the system’s overall quality and usability, ensuring that the system is not only effective in reducing the fall rate of non-metallic surgical instruments but is also durable, safe, and compliant with regulatory standards. It is important to clarify that these non-functional requirements will need to be applied to the final, market-ready design/product. The current design presented in this thesis serves as a functional and look-alike prototype, developed to assess device effectiveness and gather feedback from users. The key non-functional requirements are as follows: - Durability: The system must be robust and durable to withstand being used in the operating room even for long cases, and not malfunction or break down mid-case. 12 - Regulatory Compliance: The system must adhere to all relevant medical regulations and standards in its class, such as those set by Health Canada and the FDA. This includes ensuring that the materials used in the system comply with ISO 10993 standards for biocompatibility. Also, if the system is designed to be reusable it must adhere to ISO 17665 standards for resterilization. However, if it was designed to be as a single-use device, resterilization requirements may not apply. - Cost-Effectiveness: The system should have a reasonable cost and provide a financially viable solution by balancing the cost of production with the potential saving it may provide by reducing the cost of dropped surgical instruments and the increase in surgical efficiency. For instance, preventing a single instrument drop could save approximately $44 to $120 in OR time costs alone, with potential additional cost savings from avoiding the need to replace or re-sterilize the dropped instrument. Therefore, the system should be able to be sold for a price at least somewhat below the typical expected cost savings to ensure it remains cost-effective for the healthcare system. 2.2 Concepts: 2.2.1 Project Inception: The idea for the project originated during UBC Surgical Innovation Week held in Vancouver in 2022. This intensive course brought together surgical residents and engineering students to tackle real-world healthcare challenges through innovative solutions. The program was a collaboration between UBC General, Cardiac, and ENT Surgery Residents and UBC Engineers in Scrubs, the Vancouver General Hospital Foundation, and various healthcare leaders and experts from across 13 North America. Every year participants are given a theme/challenge that they need to work through and come up with an innovative way to approach it. The theme for the week-long event was “How might we improve the environmental performance of healthcare delivery in the operating room in a way that reduces cost and waste?”. The program was structured so each team would be multidisciplinary with different skills and prospective. Our team consisted of three surgical residents – Abdullah Mashat (the author of this thesis), Claire Liu, and Sorush Rokui – and one engineering student, Luke MacLean. Through discussions with various stakeholders in the OR, including surgeons and nurses, our team identified a significant issue: the frequent dropping of non-metallic surgical instruments. These instruments are often single-use, and must be discarded once they are dropped as they are not designed to be sterilizable, leading to considerable waste of time and resources when replaced in the middle of a surgical case. Existing solutions that decrease instrument drops such as magnetic drapes are only effective for metallic instruments but not for non-metallic ones. It is important to clarify that these discussions were not part of a structured qualitative study or formal interviews. Instead, they were informal conversations conducted as part of the SIW program, where we were encouraged to engage with OR stakeholders to identify “pain points” and areas for improvement and future research. 14 2.2.2 Early Prototypes: During the week program, our team developed a very primitive prototype, where we experimented with attaching small magnets onto a surgical cautery tool using tape and testing how it feels to have it attached to and detached from a metallic surface, as shown in Figure 3. This was mainly to test the feasibility of the concept. Although this prototype was rudimentary, it did enable us to image what the system could potentially look like and the need for further development. Figure 3 - Early prototype during SIW While we did not pursue further development or conduct a proof-of-concept study immediately after SIW, that experience laid the groundwork for potential future developments and undertaking this thesis. The goal of this thesis was to further develop our initial concept and carry out a proof-of-concept study to gain more insight into the real-world usability and efficacy of this system. 15 2.3 Developments 2.3.1 Iterative Refinement The initial phase of the prototyping and design process was focused on determining the best way to attach magnetic clips to non-metallic surgical instruments, specifically the monopolar cautery tool. I wanted to find a way to do so while still adhering to the initial set of requirements. The first concept explored was inspired by the mechanism of a ratchet hose clamp (Figure 4). Figure 4 - Off-the-shelf rachet hose clamp 16 To test out this concept, I attached circumferential small magnets around an off-the-shelf ratchet hose clamp, Figure 5,6. The design was made to take advantage of the rachet mechanism, allowing it to be able to fit instruments with various sizes. Also, it facilitated easy attachment and detachment. However, during internal testing one of the issues I found was that, given the tapered shape of the cautery tool, with extensive use, the clip would slip up away from the cautery tool into the wired cord. Moreover, a considerable amount of force was needed for the ratchet to be closed using hands alone. Figure 5 - Rachet clamp with circumferential magnets 17 Figure 6 - Application of the rachet magnetic clip on a surgical cautery tool device As such, although the rachet clip design had potential and a number of advantages, a need for a better way to secure the clips that was more fixed and not prone to slippage was needed to be explored. 2.3.2 Final Design: The limitation of the initial hose clamp prototype, especially with regard to its tendency to slip on sloped instruments during surgery, highlighted the need to explore a more secure design that is better fixed to the desired attachment site of a device during the entire case. This led to the development of the next concept design, which consists of two L-shaped components that each 18 would cover two surfaces of the surgical instrument when attached. When both are attached, the instruments would have 360 degree coverage by the clips. Figure 7 shows a Computer-Aided Design (CAD) schematic design of the clips designed using Onshape solid modelling software, where it shows the outside surfaces of the clips. After the clips are printed, small magnets are attached to their external surfaces, and on the inner surface a strong adhesive was placed to allow it to stick to the surgical instrument. For the functional prototype used in this thesis for the effectiveness testing, we used a super glue as an adhesive, for the ready for market prototype it should use a biocompatible strong adhesive. The envisioned use case for the clip would be that the clips would be attached to the desired surgical instrument at the beginning of the surgical case. Figure 8 demonstrates the application of these clips on a cautery tool device. 19 Figure 7 - CAD schematic of the L-shaped design of the magnetic clip 20 Figure 8 - Application of L-shaped magnetic clip on a monopolar cautery tool device While the ratchet clip concept was promising, pilot testing of this new clip design in a simulated OR environment suggested that the adhesive approach could provide a sufficiently secure attachment to the cautery tool. As a result, we decided to advance this concept into the verification testing phase. 21 2.3.3 Holding station The development of the magnetic clips was made in order to make non-metallic surgical instrument such as the cautery tool compatible with conventional magnetic drapes. However, a practical challenge emerged – these magnetic drapes are usually relatively large in size and are placed on the patient’s hips, which can be far from the ideal placement of the cautery tool which is usually fixed near the surgeon’s dominant hand, depending on which side of the patient bed the surgeon is standing. As such, we saw the need to develop a magnetic docking station specifically designed to hold the cautery tool equipped with our clip, that will provide surgeons with the freedom to always have the cautery tool within easy reach during surgery. The docking station we designed, as shown in Figure 9, features a metallic surface with multiple small magnets that are designed to hold on to a cautery tool equipped with the magnetic clip and prevent it from slipping or becoming dislodged. The back surface of the docking station is equipped with a curved artery forceps, which allows it to be securely clipped onto the patient drapes even at steep angles, as shown in Figure 10. The choice of using a curved artery forceps as the fixation method was made as surgeons are already familiar with using artery forceps for tissue dissection in the majority of their OR cases and they often use these forceps to fix tethered instruments such as cautery wires and suction tubing to the drapes during surgery. By incorporating this familiar tool into the docking station's design, the use of the docking station would feel more intuitive and natural to most surgeons. 22 Figure 9 - Magnetic docking station for securing the cautery tool, featuring a metallic surface with embedded magnets and a curved artery forceps for attachment to patient drapes. 23 Figure 10 - Docking station securing a cautery tool equipped with a magnetic clip at a steep angle 24 Chapter 3: Verification Methodology 3.1 Challenges in Testing and Rationale for Accelerated Failure Model Evaluating the efficacy of a device designed to prevent the dropping of surgical instruments presented a significant challenge, when considering real-world OR conditions. On average, instrument falls have been found to occur 1.5 to 2 hours into a procedure (Khan, 2008). This infrequency of falls implies that it would be difficult to gather sufficient validation data within reasonable study times. If the data were acquired during a real clinical trial, it would require monitoring across numerous surgeries, making the process not only time consuming but also expensive. Moreover, real-world testing would require prior health care regulation of the device and logistical complexities that would be resource intensive. Even in a simulated OR environment, where many of the prior limitations can be mitigated, replicating the exact moment when an instrument is likely to fall remains challenging. Since instrument drops are relatively infrequent, naturally occurring at intervals of hours rather than minutes, creating a creating a realistic scenario to capture and study the drop rate changes would require lengthy simulation testing that would make it difficult to recruit participants. As a result, conventional testing approaches would not yield sufficient drop events to accurately assess the device's performance. To overcome these challenges, we designed an accelerated test model as the primary methodology for this study. This approach allows for simulating "worst-case" scenarios where the likelihood of instrument drops is significantly increased. By artificially creating conditions 25 that are more prone to trigger or elicit instrument drops and incorporating many risk factors that are associated with increase instrument fall. By accelerating the conditions that lead to instrument falls, we can gather meaningful data on the device effectiveness in a realistic timeframe. This method of accelerated testing has been used in various engineering and product development fields, where it aims to simulate the long-term effect of a normal use in a much shorter duration by applying higher level of stress and risk factors to a studied device or subject (Klyatis, 2020; Escobar & Meeker, 2006). This methods provides insight into potential failure points by identification of human errors under intensified conditions, which are often missed under normal circumstances. For instance, studies like those by Jamshidi and Sadeghi (2022) have shown that accelerated testing can be effective in capturing the impact fatigue and other stressors on human performance. 3.2 Study Design: The study was designed as an experimental simulation to evaluate the effectiveness and integration of an innovative magnetic attachment intended to prevent the falling of non-metallic surgical instruments such as monopolar cautery tools and plastic suction, in a simulated OR environment. The testing was conducted in a mock surgical suite at Centre for Aging SMART (CASMART) at VGH that was equipped with many essential elements of a real surgical environment. This included an operating table, OR lights and essential surgical instruments. 26 To ensure the study results were as relevant as possible, we only included participants who were surgeons or surgical residents who were post-graduate-year (PGY) 2 or more. Participants were selected based on their availability and volunteering to engage in the simulation exercises, with efforts made to recruit participants from diverse surgical specialties. The study was conducted under UBC CREB Number: H24-01189. 3.3 Operating Table Design Setup: The OR table setup was designed in a way that would increase the risk of instrument fall but still retain important elements of real surgical environments. The instruments included in the simulation included a monopolar cautery tool, plastic suction, mosquito forceps, Addison forceps and suture scissors. In this setup, the monopolar cautery tool was equipped with the magnetic attachment clips. Moreover, because the cautery tool can only work if it was used on a living tissue, an Apple pencil was attached to the cautery tool to allow it to be used on an iPad screen and mimic the motion of an incision using the cautery tool. The inside of the simulated surgical field included various simulated surgical tasks that included a suture trainer silicon pad, a peg transfer exercise, an iPad and an area where the suction can be placed, as shown in Figure 11. We then set up the OR with the magnetic retention system as shown in Figure 12. The selection of these surgical tasks such as suturing, peg transfer, and practicing incisions in our simulated OR was grounded in their recognized importance within surgical training literature. Suturing is a foundational surgical skill that is critical for surgical proficiency and widely used in 27 simulation and training environments (Almeida et al., 2023; Belmar et al., 2023). It also an essential part of the American College of Surgeons and the Association simulation-based surgical skills curriculum (Acton et al., 2015). Similarly, the peg transfer task, well-documented in the literature as a validated method for evaluating precision and dexterity, which are critical skills during handling multiple surgical instruments (McCluney et al., 2007; Dauster et al., 2005). Lastly, the incision task, similar to suturing, is an essential task in almost every surgery, Halfwerk et al. (2020) emphasize the importance of incision tasks as one of the core tasks when they developed a simulation-based course for basic surgical skills. Figure 11 - Inside of the surgical simulation model showing different training exercises 28 Figure 12 – Simulated OR setup with the magnetic retention system in place, including the docking station for the cautery tool and a magnetic drape on the left for the rest of the instruments. Several elements were incorporated into the simulated design to increase the likelihood of instrument drops; these included: - Reduced operating table space: The space available on the operating table was intentionally limited, requiring participants to carefully manage instrument placement. 29 - Tilted table edges: Each of the table edges were slightly placed on a slop to mimic the patient abdomen curvature. - Time pressure: Participants were given a limited amount of time to complete each task with a red 10 second countdown timer that appears towards the end of each task. - Rapid Instrument Switching: The chosen simulated surgical tasks required participants to switch instruments frequently and quickly, further raising the likelihood of mishandling and potential drops. - Double Gloving: Participants were instructed to wear double gloves on each hand to mimic a real OR situation; this added a layer of challenge when handling instruments. - Auditory Distractions: To mimic a chaotic emergency OR environment, loud sounds of beeping monitors and ventilatory machines were played in the background. The sounds ranged from a monitor sound of a stable patient to a more alarming sound of a hemodynamically unstable patient. 3.4 Simulation Procedure The simulation test consisted of a control phase without using the magnetic clip and magnetic drape functions and a test phase where the magnetic drape and clip were used. Both conditions were performed twice in an alternating fashion for a total of 4 phase/sessions, each lasting 6 minutes. To account for any effects from having Participants were asked to perform a series of surgical tasks, psychomotor skills and decision-making activities. These included performing incisions, solving mazes, suturing, suctioning and peg transfer, as shown in Figure 13. Each task had a limited time to be completed and as the 30 session passes the time allowed for each task was reduced. Participants had a monitor beside the OR table that played a video which prompted them to proceed to the specific task they were required to do next. Figure 13 - Flowchart showing the sequence of surgical tasks participants go through during each session, this included solving mazed on an iPad screen using an apple pencil attach to the 3.5 Performance Scoring and Evaluation: The quality and efficiency of the participants' performance were evaluated using two criteria: the percentage of task completion and the time taken to transition to the next task. As each task was given a limited time to be completed, participants were evaluated based on how much of each task they completed in the timeframe. This was evaluated on a scale of 1 to 4, as shown in Table 1. Secondly, transition efficiency was scored on a scale of 0 to 2, to evaluate how quickly participants moved from one task to the next after the timer signaled the end of the current task, as shown in table 2. 31 The overall performance score for each participant was calculated by summing the scores for task completion and transition time, resulting in a total score out of 6 points. Table 1 - Task Completion Scoring Percentage of Task Completed Score 0% 0 1% - 25% 1 26% - 50% 2 51% - 75% 3 76% - 100% 4 Table 2 - Transition Time Scoring Transition Time Score Less than 2 seconds 0 3 - 5 seconds 1 More than 5 seconds 2 This scoring system was implemented to determine whether any improvements in drop rates were achieved at the expense of task performance quality or efficiency. 32 3.6 Data Collection and Analysis Demographics of participants were recorded, including their surgical specialty and the number of years of clinical experience. All simulation sessions were videorecorded with prior consent from the participants. These recordings were used to document the number of instrument drops during each phase of the simulation. Participant feedback was collected through both structured surveys and open-ended interviews immediately following the mock surgery sessions. These surveys were designed to capture outcomes related to the effectiveness and usability of the magnetic attachment, with responses rated on a Likert scale of 1 to 5. In addition to the quantitative data, qualitative feedback was gathered through open-ended questions, which provided participants the opportunity to express their opinions on the device’s potential integration into their daily clinical practice and to offer suggestions or comments; more details can be found in appendix A. Data analysis was conducted using SPSS Statistics for Mac Version 29.0 (IBM Corp, Armonk, New York, USA). Descriptive analysis was used to summarize the demographic characteristics of the participants and the rate of fall in all participants. The differences in the rate of instrument falls between the control and test phases were compared using a paired t-test, with a p-value of <0.05 considered statistically significant. Additionally, Cohen’s d statistic was calculated to assess the effect size and the impact of that difference. 3.7 Ethical Consideration The study was conducted after approval was obtained from the UBC Research Ethics Board (UBC CREB Number: H24-01189). All participants provided informed consent before starting 33 the experiment and were fully briefed on the study's purpose, procedures, and their rights, including the option to withdraw at any time - see appendix B. 34 Chapter 4: Verification Results This section presents the key findings of the study, focusing on the effectiveness of the magnetic attachment system in preventing the fall of non-metallic surgical instruments. The results are drawn from both quantitative data such as the rate of falls in the different phases of the experiment and from participants’ feedback and experience. A total of seven participants were in involved in the study from various surgical specialties and levels of residency. Table 3 summarizes the demographic information of the participants, including their specialty and level of residency. The majority of the participants were from General Surgery, and the remaining were from either from Vascular surgery or orthopedics. Table 3 - Participant demographics Participant Number Specialty Level of Residency Number of surgical procedures preformed 1 General Surgery PGY-4 750 2 Vascular Surgery PGY-3 250 3 General Surgery PGY-2 80 4 General Surgery PGY-2 110 5 General Surgery PGY-2 140 6 General Surgery PGY-3 180 7 Orthopedic Surgery PGY-4 600 35 Each participant preformed 4 sessions of the experiments, with two under the control condition (with the magnetic attachment system) and two under the test condition (with the magnetic attachment system); these were performed in an alternating fashion. Without the magnetic attachment, the participants experienced a range of 1 to 18 instrument falls during the simulations. The mean number (SD) of instrument falls in this condition was 7.57 (SD: 5.77). In contrast, when the magnetic attachment system was used, the number of falls ranged from 0 to 2, with an average of 0.86 (SD: 0.90), as shown in table 4. Figure 14 presents the number of instrument falls recorded for each participant under both conditions, which illustrates the substantial decrease in fall rates when the magnetic attachment system was employed. Figure 14 - Clustered bar chart illustrating the comparison of instrument falls with and without the Magnetic Attachment System across participants. 36 Table 4 - Summary of Instrument Falls with and without the Magnetic Attachment System, showing a marked reduction in falls when the system is used. Condition Mean Instrument Falls Standard Deviation Minimum Maximum Without Magnetic Attachment 7.57 5.77 1 18 With Magnetic Attachment 0.86 0.90 0 2 To statistically evaluate the effectiveness of the magnetic attachment system, a paired t-test was used. The analysis revealed a significant mean difference of 6.71 falls, with participants experiencing fewer instrument falls when the magnetic attachment system was used, p-value <0.05. To further assess the practical significance of this chance, Cohen’s d was calculated. The resulting effect size was calculated as 1.359, which indicates that the magnetic attachment system has a strong impact on the reduction of instrument falls. According to Cohen (1988), effect sizes of 0.2, 0.5, and 0.8 are typically interpreted as small, medium, and large, respectively, with values above 0.8 representing a large effect size (Fritz et al., 2012). Further details are shown in Tables 5 and 6. Table 5 - Paired t-Test Results Mean Difference Std. Deviation Std. Error Mean t Two-Sided p 6.857 5.047 1.908 3.594 0.005 37 Table 6 - Effect Size (Cohen's d) The side-by-side box plot (Figure 15) provides a visual comparison of the number of instrument falls in the two conditions, and shows a significant reduction in the median number of falls when the magnetic attachment was used. Figure 15 - Side-by-side box plot showing the reduction in instrument falls with and without the magnetic attachment system. Bold line = median; box length = interquartile range (IQR); error bars = range; circle = outlier. Effect Size (Cohen's d) 95% Confidence Interval (Lower) 95% Confidence Interval (Upper) 1.359 0.279 2.387 38 A sub-analysis was conducted to examine the effect of the magnetic retention system on only non-metallic surgical instruments used in the experiment. The cluster bar chart (Figure 16) illustrates the mean number of falls for the monopolar cautery tool with and without the magnetic retention system for each participant. Using the Wilcoxon Signed-Rank Test, there was a significant reduction in the number of falls of non-metallic instruments with the magnetic retention system compared to the control, p-value < 0.05. Figure 16 - Clustered bar chart illustrating the mean number of falls for non-metallic instruments with and without the magnetic retention system. With regard to the overall performance differences between the two groups, participants showed significant improvements in task completion rates and transition efficiency under the magnetic condition compared to the control condition. When the magnetic retention system was used, 39 participants had an overall mean performance score of 5.19 (SD = 1.19), compared to 4.21 (SD = 1.26) for the control condition, as shown in Figures 17. A Wilcoxon signed-rank test confirmed that this difference was statistically significant with a p-value < 0.05. A Wilcoxon signed-rank test was performed separately on each sub-score. For task completion rates, participants had a statistically significant improvement with the magnetic retention system (p < 0.05). However, the transition efficiency score, although better under the magnetic condition, did not reach statistical significance (p = 0.104). Figure 17 - Mean total performance scores between control and magnetic conditions across participants., with contributions from the task completion and transition efficiency components shown in different shades. Panel A represents the control condition, and panel B represents the magnetic retention system condition To evaluate whether participants experienced fewer instrument drops as they became more familiar with the simulation, a paired samples t-test was conducted comparing the first and second rounds of the experiment for each of the control and test groups. The analysis showed no 40 significant differences in the number of instrument drops between the first and second rounds, either with or without the magnetic attachment system (p = 0.175 and 0.517, respectively). The post-simulation feedback questionnaire revealed overall strong support for the use of the magnetic retention system. Participants indicated that the system would be easily integrated into their daily clinical practice with the interaction being rated as highly intuitive (mean ratings of 4.4 and 4.8 out of 5, respectively). Despite being a new system that is not used in the OR, participants did not anticipate that it would disrupt their focus or workflow (mean = 1.8). Lastly, they strongly thought that this system would increase their efficiency if they would use it in a real OR on a regular bases and that they would recommend it to be used in the OR (mean = 4.5). These results, illustrated in Figure 18, suggest that the magnetic retention system has significant potential for adoption in clinical practice. 41 Figure 18 - Mean scores for key usability aspects of the magnetic retention system. Participants rated each item using a 5-point Likert scale, with higher scores indicating stronger agreement. 42 Chapter 5: Discussion: The purpose of this study was to develop and evaluate a magnetic retention system intended to effectively decrease the rate of non-metallic instrument falls in the OR. By designing small magnetic clips that are attached to such instruments, we were able to make them compatible with conventional magnetic drapes that are commonly used in the OR. 5.1 Research Questions: The first objective of this thesis work was to design and develop a magnetic retention system intended to prevent the fall of non-metallic instruments. This was addressed through an iterative design process, followed by testing the prototype in an accelerated usage setting. This study demonstrated that using the system enabled users to complete the surgical tasks with markedly fewer instrument drops, while simultaneously improving their task completion and transition efficiency scores. A sub-analysis focused on non-metallic surgical instruments showed that the magnetic retention system significantly decreased the drop rate of these instruments, confirming the device's potential to enhance the retention of non-metallic instruments during surgery. These findings demonstrate significant potential for the device to improve the retention of these non-metallic instruments during surgery, thus meeting the first objective of the thesis. This process was guided by specific pre-set functional and non-functional requirements. This challenge required the design of a system that could allow for the integration with existing OR practices in a seamless way while introducing a novel solution. 43 The first design for the magnetic clip that was explored involved the use of a ratchet clamp like design, this allowed for the versatility in fitting instruments with various sizes. Although this was a promising design, during internal testing we identified a significant design issue: the tapered shape of instruments like the monopolar cautery tool caused the clamp to slip, especially with extended use. Moreover, the force required for closing the ratcheted clip was considerable when done bare-handed. Acknowledging these limitations, we moved on to explore a new design concept: the L-shaped clip. The clip provided 360-degree coverage and addressed the slippage issue by using a strong adhesive that ensured the clip was fixed to a specific spot on the instrument during the entire surgical procedure and simplified the process of attaching to the instrument at the beginning of a case. The L-shaped design was the design we settled on as the primary design to be carried over to the verification stage, as this design satisfied the requirements we needed such as secure attachment, ease of use, and compatibility. Evaluating this design intraoperatively posed significant logistical challenges, as regulatory approval from Health Canada or FDA need to be first acquired before any real world testing, requiring a lengthy double-arm clinical trial, that would demand substantial time and financial resources. In addition, the relatively low frequency of instrument drops in the live operating room would require a long period of monitoring. To overcome these challenges, we developed a novel accelerated testing model using a simulated surgical environment. Accelerated testing is a technique that is used in various engineering and 44 product development fields, where it aims to simulate the long-term effect of a normal use in a much shorter duration by applying higher level of stress and risk factors to a studied device or subject (Klyatis, 2020; Escobar & Meeker, 2006). In the context of our study, we designed a simulated environment which aimed to emulate scenarios in which surgical instruments are at risk of fall. This approach allowed for rigorous testing under controlled conditions, providing reliable data on the system's effectiveness without the limitations and constraints of real-world trials. This accelerated failure model represents a versatile evaluation method and expands the scope of solutions available for managing surgical instruments and studying the effectiveness of new medical innovations in this field. 5.2 Relation to Other Literature The literature on surgical instrument fall in the OR is limited, with only 3 studies identified that examined the incidence rate of these falls. Despite the scarcity of research, these studies have reported significant findings with generally consistent results between the studies. In these studies, the rate of instrument falls ranges from about 30% to 60%, with the biggest determining factor being whether the surgery was elective or emergency (Khan et al., 2008; Sedigh et al., 2019; Joshi et al., 2012). Emergency surgery is significantly more associated with instrument drops than elective cases, one of the reasons likely being that during the fast-paced and high-pressure environment of emergency surgeries, shortcuts in organizing and and handling tools are often taken (Whalan, 2009; Osborne, 1999). Sedigh et al. (2019) is the only study in the literature to have explored the effect of an intervention on decreasing the rate of instrument falls. For their study, they conducted a double-45 arm clinical trial with two groups – a control (not using magnetic drape) and an interventional group (using magnetic drape) – and observed 200 surgeries in various different surgical departments. They demonstrated a substantial reduction in the rate of instrument drops in the magnetic drape group, from 55% in the control group to 19% in the intervention group. This shows the potential effectiveness of magnetic solutions in decreasing the rate of instrument falls. In comparison, our study aimed to address a similar challenge, but with a focus on non-metallic instruments, which cannot directly make use of traditional magnetic drapes. This was possible due to the introduction of a novel method that can make non-metallic instruments compatible with magnetic drapes, thus extending the scope of solutions available for preventing instrument falls. Similar to Sedigh et al. (2019) our results also showed a significant reduction in instrument fall rates, with a mean reduction in the number of instrument drops of 6.7 per case. In principle, it may have been possible that participants dropped fewer instruments when using the magnetic retention system during the simulation test, at the expense of task performance and completion time (i.e., they could have simply moved more slowly when using the system and so dropped fewer instruments). However, the results showed the opposite. The magnetic retention system group not only maintained the quality of task performance and timing but actually enhanced it. Participants demonstrated better performance scores when using the magnetic retention system, which highlights the potential of increased surgical efficacy when using the new system. Moreover, this is also consistent with post-simulation feedback, where participants noted that they thought that this system would increase their efficiency if they would use it in a real OR on a regular basis and said that they would recommend it to be used in the OR (mean ratings of 4.4/5). 46 5.3 Limitations: Despite the study’s promising results, several limitations need to be acknowledged. First the study verification methodology used a simulated OR environment, which, although it was designed to mimic real-world surgical conditions as closely as possible, cannot fully replicate real OR conditions. Several factors related to surgical team dynamics and longer-duration surgical procedures were not captured in our setting, so performance in the live OR is still undetermined. Sedigh et al. (2019) conducted their study in a real OR setting, as magnetic drapes are already an approved medical device. This allowed them to implement the intervention directly into clinical practice, and allowed for a “real-use” assessment of the drape’s effectiveness under normal surgical conditions. In contrast, our study faced several logistical challenges, as it was a novel device and therefore did not have health regulatory approval. As such, we opted to evaluate our system in a simulated environment. Moreover, we designed our simulated model to allow for accelerated testing, which enabled us to better capture the effects of this new magnetic retention system within a realistic time frame. While this method of testing might have limitations, this model of accelerated testing can be also adopted by other innovators seeking to evaluate new medical technologies aimed to reduce instrument rates of fall as a practical and efficient pathway prior to (and to justify) clinical testing. 47 One of limitations of the study was the lack of randomization when assigning participants whether to start the experiment with the control or magnetic conditions. This raises the possibility that the improvements in the drop rate seen in the magnetic retention system condition was due to the effect of the magnetic retention system itself or simply due to participants becoming more familiar with the simulation tasks over time. To address this, we conducted a paired-t test that showed that there were no significant differences in the drop rate between the first and second rounds for either condition, suggesting that the improvement in drop rate seen with the magnetic system was not simply due to familiarity with the tasks. Another point to be discussed was the presence of several outliers. For instance, participants 1 and 7 had the most extreme rates of instrument drops, with one being very high and the other very low. These variations could reflect individual differences and habits in tool handling. Additionally, it was noted that participant 4 was the only one whose performance score remained constant and did not improve when using the magnetic retention system. The effectiveness of the magnetic retention system relies on users’ compliance. The proper attachment and use of the system by the surgeons and residents are crucial to its success. As a result, inconsistent or improper use of this system by the surgical team could potentially reduce its effectiveness. Nonetheless, users reported little or no difficulty in using the system, and, as noted above, overall performance in the simulated surgical tasks improved relative to the control condition, so we do not anticipate any significant impact on surgical performance in the live operating room. 48 5.4 Recommendations and Future Work: This study has laid a foundation for the design and development of a magnetic retention system for non-metallic surgical instruments. It also has developed an accelerated testing method for evaluating innovations in this space. However, several areas remain for further research and development. First, as a pilot study, we focused on developing the magnetic clips and tested them on the monopolar cautery tool and plastic suction devices as a starting point, given that they are the most used non-metallic instruments in the OR. Future work should explore the system’s adaptability to a broader range of surgical tools with varying shapes and sizes such as bipolar cauterizers, harmonic scalpels, surgical staplers, and others. To further build on the promising results obtained by the simulated model, it is import to validate the magnetic retention system in real-world OR settings. The current results justify moving this device forwards towards conducting a clinical trial aimed at more comprehensively evaluating the system’s overall impact on the surgical workflow, efficiency, and cost-effectiveness. Such studies could also evaluate the environmental impact of the system with regard to reducing surgical waste and associated carbon emissions. With regard to the regulatory classification of the magnetic clip designed to attach to non-metallic instrument, we assessed the device based on the Health Canada guidelines (Health Canada, 2015). Based on the intended use of the device, we feel that it would most likely be considered a class II medical device. This is based on Rule 1 of the Health Canada regulatory classification, which regards all surgically invasive disposable surgical instruments as being of class II, including relatively benign devices such as surgical gloves and internal sponges. The 49 magnetic clip, although not directly invasive itself, is associated with a surgically invasive procedure as it attaches to a cautery tool, which is used inside the body during surgery. The classification is not altered by Rule 3, which excludes reusable instruments. This classification would require a pre-market notification and a device license from Health Canada before being marketed. As the project moves toward potential commercialization, several factors must be carefully considered, including production costs, pricing strategies, profit margins, and market demand. These considerations will be critical in determining the financial viability of the system and ensuring its successful adoption in the healthcare market. In addition, further functional considerations should be addressed. The magnetic clips are designed to be lightweight and small to ensure it does not interfere with the functionality or grip of the surgical instruments to which it is attached, but, since surgical devices vary, the device’s attachment site is important, and moving forward we intend to develop comprehensive user instructions identifying recommended placement sites for common non-metallic surgical instruments (and/or modifying the design to accommodate differently shaped instruments). Lastly, given the nature of medical innovation, testing is challenging because of the associated logistical and ethical considerations. The accelerated testing simulation model developed in this study has shown promising results on how it can be used to gain insight into a proposed medical device’s effectiveness before clinical trials. Moreover, future research can modify and adopt this method of testing as a versatile tool for evaluating a wide range of medical devices in the pre-clinical phases. 50 5.5 Conclusion: This study successfully designed, developed and evaluated a magnetic retention system aimed at reducing the incidence of non-metallic instrument falls in the operating room. By designing attachable magnetic clips, we were able to make non-metallic surgical instruments compatible with conventional magnetic drapes. The use of a simulated OR and an accelerated testing model allowed us to assess the system’s effectiveness. 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Thesis/Dissertation
eng
Experimental Medicine
Vancouver : University of British Columbia Library
Attribution-NonCommercial-NoDerivatives 4.0 International
Graduate
Mui, Alice
Hodgson, Antony J.
Design and evaluation of a device to prevent instrument drops during surgery
Text