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<p><strong>A compatible interface between a biomedical material and host tissue is paramount to the continual function and life-span of medical devices that reside in the body. However, the unfavourable host response that ensues when foreign materials inhabit the body must be overcome for sophisticated medical devices, such as artificial organs and real-time biosensors, to be used clinically. My thesis research commenced with a search to find a pharmaceutical compound that could be incorporated into a medical device to suppress the accumulation of fibrous tissue. A prolyl hydroxylase inhibitor, a drug developed to inhibit collagen synthesis, was found to be effective at inhibiting collagen deposition within and on the outer surface of a poly(lactic-glycolic acid) disc, and also limited connective tissue ingrowth. Furthermore, the drug suppressed Scavenger Receptor A (SRA) expression on a macrophage-like cell culture, a receptor known to contain a collagenous domain. The latter finding prompted a review of the literature, upon which it was discovered that SRA mediates leukocyte adhesion and binding to an assortment of materials, such as silica, modified polystyrene, titanium, and iron(III) oxide. As a result, a series of studies were initiated to investigate whether leukocytes use SRA to detect a range of different biomedical materials. Consequently, we found that SRA contributes very little to leukocyte binding of two common medical polymers, polystyrene and poly(lactic-co-glycolic acid), but may interact with the materials to affect the cytokine profile in the local environment. In a subsequent study, SRA was found to be crucial to the leukocyte binding of polyanionic hydrogels. In summary, we have identified a unique pharmaceutical strategy for suppressing the accumulation of fibrous tissue on medical devices in vivo, and uncovered a mechanism of leukocyte stimulation in response to incubation with biomedical materials that the material science research community was not previously aware of. </strong></p> / Doctor of Philosophy (PhD)

Background: Majority of cancer interventions today are performed percutaneously using needle-based procedures, i.e. through the skin and soft tissue. Needle insertion is known as one of the recent needle-based techniques that is used in several diagnostic and therapeutic medical procedures such as brachytherapy, thermal ablations and breast biopsy. The difficulty in most of these procedures is to attain a precise navigation through tissue reaching target locations. Insufficient accuracy using conventional surgical needles motivated researchers to provide actuation forces to the needle’s body for compensating the possible errors of surgeons/physicians. Therefore, active needles were proposed recently where actuation forces provided by shape memory alloys (SMAs) are utilized to assist the maneuverability and accuracy of surgical needles. This work also aims to introduce a novel needle insertion simulation to predict the deflection of a bevel tip needle inside the tissue. Development of a model to predict the behavior of the needle steering in the soft tissue has been always a point of interest as it could improve the performance of many percutaneous needle-based procedures. Methods: In this work first, the actuation capability of a single SMA wire was studied. The complex response of SMAs was investigated via a MATLAB implementation of the Brinson model and verified via experimental tests. The material characteristics of SMAs were simulated by defining multilinear elastic isothermal stress-strain curves. Rigorous experiments with SMA wires were performed to determine the material properties as well as to show the capability of the code to predict a stabilized SMA transformation behavior with sufficient accuracy. The isothermal stress-strain curves of SMAs were simulated and defined as a material model for the Finite Element Analysis of the active needle. In the second part of this work, a three-dimensional finite element (FE) model of the active steerable needle was developed to demonstrate the feasibility of using SMA wires as actuators to bend the surgical needle. In the FE model, birth and death method of defining boundary conditions, available in ANSYS, was used to achieve the pre-strain condition on SMA wire prior to actuation. This numerical model was validated with needle deflection experiments with developed prototypes of the active needle. The third part of this work describes the design optimization of the active using genetic algorithm aiming for its maximum flexibility. Design parameters influencing the steerability include the needle’s diameter, wire diameter, pre-strain, and its offset from the needle. A simplified model was developed to decrease the computation time in iterative analyses of the optimization algorithm. In the fourth part of this work a design of an active needling system was proposed where actuation forces of SMAs as well as shape memory polymers (SMPs) were incorporated. SMP elements provide two major additional advantages to the design: (i) recovery of the SMP’s plastic deformation by heating the element above its glass transition temperature, and (ii) achieving a higher needle deflection by having a softer stage of SMP at higher temperatures with less amount of actuation force. Finally, in the fifth and last part of this study, an Arbitrary-Lagrangian-Eulerian formulation in LS-DYNA software was used to model the solid-fluid interactions between the needle and tissue. A 150mm long needle was considered to bend within the tissue due to the interacting forces on its asymmetric bevel tip. Some additional assumptions were made to maintain a reasonable computational time, with no need of parallel processing, while having practical accuracies. Three experimental tests of needle steering in a soft phantom were performed to validate the simulation. Results: The finite element model of the active needle was first validated experimentally with developed prototypes. Several design parameters affecting the needle’s deflection such as the needle’s Young’s modulus, the SMA’s pre-strain and its offset from the neutral axis of the cannula were studied using the FE model. Then by the integration of the SMA characteristics with the automated optimization schemes an improved design of the active needle was obtained. Real-time experiments with different prototypes showed that the quickest response and the maximum deflection were achieved by the needle with two sections of actuation compared to a single section of actuation. Also the feasibility of providing actuation forces using both SMAs and SMPs for the surgical needle was demonstrated in this study. The needle insertion simulation was validated while observing less than 10% deviation between the estimated amount of needle deflection by the simulation and by the experiments. Using this model the effect of needle diameter and its bevel tip angle on the final shape of the needle was investigated. Conclusion: The numerical and experimental studies of this work showed that a highly maneuverable active needle can be made using the actuation of multiple SMA wires in series. To maneuver around the anatomical obstacles of the human body and reach the target location, thin sharp needles are recommended as they would create a smaller radius of curvature. The insertion model presented in this work is intended to be used as a base structure for path planning and training purposes for future studies. / Mechanical Engineering

The needle-based procedures are usually considered minimally invasive. However, in insertion into soft tissues such as brain and liver, the tissue damage caused by needle insertion can be very significant. From the literature, it has been known that reduction in needle insertion and extraction forces as well as tissue deformation during the insertion results in less invasive procedure. This work aims to design and develop a new bioinspired design for surgical needles which reduce the insertion and extraction forces of the needle, and its damage to the tissue. Barbs in honeybee stinger decrease its insertion force significantly. Inspired by that finding, a new honeybee-inspired needle was designed and developed, and its insertion mechanics was studied. To study the insertion mechanics of honeybee-inspired needle, insertion tests into artificial and biological tissues were performed using both honeybee-inspired and conventional needles. The barb design parameters effects on needle forces were studied through multiple insertion and extraction tests into PVC gels. The design parameters values of the barbs were experimentally modified to further reduce the ultimate insertion and extraction forces of the needle. Bioinspired needle with modified barb design parameters values reduces the insertion force by 35%, and the extraction force by 20%. To show the relevance, the insertion tests into bovine liver and brain tissue were performed. Our results show that there was a 10-25% decrease in the insertion force for insertions into bovine brain, and a 35-45% reduction in the insertion force for insertions into the bovine liver using the proposed bioinspired needles. The bioinspired and conventional needles were manufactured in different scales and then used to study the size scale effect on our results. To do so, the insertion tests into tissue-mimicking PVC gels and liver tissues were performed. The results obtained for different sizes of the needle showed 25-46% decrease in the insertion force. The tissue deformations study was conducted to measure tissue deformation during the insertion using digital image correlation. The tissue deformation results showed 17% decrease in tissue deformation using barbed needles. A histological study was performed to accurately measure the damage caused by needle insertion. Our results showed 33% less tissue damage using bioinspired needles. The results of the histological study are in agreement with our hypothesis that reducing needle forces and tissue deformation lead to less invasive percutaneous procedures. / Mechanical Engineering

Yes / The use of information technology and technological medical devices has contributed significantly to the transformation of healthcare. Despite that, many problems have arisen in diagnosing or predicting diseases, either as a result of human errors or lack of accuracy of measurements. Therefore, this paper aims to provide an integrated health monitoring system to measure vital parameters and diagnose or predict disease. Through this work, the percentage of various gases in the blood through breathing is determined, vital parameters are measured and their effect on feelings is analyzed. A supervised learning model is configured to predict and diagnose based on biometric measurements. All results were compared with the results of the Omron device as a reference device. The results proved that the proposed design overcame many problems as it contributed to expanding the database of vital parameters and providing analysis on the effect of emotions on vital indicators. The accuracy of the measurements also reached 98.8% and the accuracy of diagnosing COVID-19 was 64%. The work also presents a user interface model for clinicians as well as for smartphones using the Internet of things. / Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022TR140), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.

Clinicians in low and middle-income countries (LMIC) face many challenges, including high patient-to-staff ratios, limited resources, and inconsistent access to electricity. This research aimed to improve health outcomes in LMIC through an enlightened understanding of challenges associated with healthcare technology. To understand LMIC barriers to acquiring, maintaining, and repairing medical equipment, a community-based participatory study was conducted at three clinical settings in southern Malawi. Thirty-six clinical staff participated in surveys and focus groups to provide information on medical device challenges. Results from the study emphasize the importance of community-based participatory innovation to improve global health. Many clinical staff expressed frustration regarding inability to prevent patient mortality attributed to equipment failure. Data from the community-based participatory study of medical technology conducted in Malawi revealed key insights for designing for low and middle income countries, and more specifically, for communities in southern Malawi. Specifically, partner communities identified mechanical suction machines as a top priority for design innovation. Working with technical and clinical staff in Malawian communities, a prototype mechanical suction machine was designed and constructed. This work suggests that engineers working in low and middle income countries face a unique sundry of design requirements that require an intimate understanding of the local community, including community leaders, community beliefs and values, and locally available resources. Technology innovation for global health should incorporate community expertise and assets, and health and technical education efforts should be developed to increase working knowledge of medical devices. / Master of Science / Clinicians in low and middle-income countries (LMIC) face many challenges, including high patient-to-staff ratios, limited resources, and inconsistent access to electricity. This research aimed to improve health outcomes in LMIC through an enlightened understanding of challenges associated with healthcare technology. To understand LMIC barriers to acquiring, maintaining, and repairing medical equipment, a community-based participatory study was conducted at three clinical settings in southern Malawi. Thirty-six clinical staff participated in surveys and focus groups to provide information on medical device challenges. Results from the study emphasize the importance of community-based participatory innovation to improve global health. Many clinical staff expressed frustration regarding inability to prevent patient mortality attributed to equipment failure. Data from the community-based participatory study of medical technology conducted in Malawi revealed key insights for designing for low and middle income countries, and more specifically, for communities in southern Malawi. Specifically, partner communities identified mechanical suction machines as a top priority for design innovation. Working with technical and clinical staff in Malawian communities, a prototype mechanical suction machine was designed and constructed. This work suggests that engineers working in low and middle income countries face a unique sundry of design requirements that require an intimate understanding of the local community, including community leaders, community beliefs and values, and locally available resources. Technology innovation for global health should incorporate community expertise and assets, and health and technical education efforts should be developed to increase working knowledge of medical devices.

醫療器材法律規章與監督管理制度的探討，能夠教育社會大眾遵守法律、保障醫療器材產品品質、維持市場公平競爭、保障人們使用安全和身體健康。進而對於整體醫療器材產業，可以在面對法律問題之前的法律責任、行為規則、違法情形以及類推適用作為憑據和參考。 本研究目的是(1)檢視中國大陸醫療器材法律規章之起源與形成由來。(2)瞭解中國大陸醫療器材監督管理制度的發展情況。(3)探討中國大陸醫療器材監督管理相對人違法責任與違法處罰行為。 本研究主要以「內容分析法」，從中英文參考書籍、學術論文以及相關市場報告、期刊文章等，蒐集具有醫療器材相關的法學理論、法規制度、監督管理等關聯性資料加以歸納整理並進行討論。其次，採用「比較分析法」，將歐盟、日本、中華民國以及美國之醫療器材法規和監督管理制度與中國大陸進行對比分析。本研究以中國大陸醫療器材法律體系、法規制度和監督管理三項研究構面進行觀察，期許呈現符合學術標準的信度與效度之研究結果。 研究結果發現，中國大陸《醫療器械監督管理條例》屬於「行政法規」層級。監督管理的方式主要為「產品上市前審查」與「產品上市後監督」。其中「產品上市前審查」需要遵循：(a)醫療器材檢測管理、(b)醫療器材註冊管理、(c)醫療器材生產管理、(d)醫療器材說明書、標籤和包裝管理與(e)醫療器材經營管理；「產品上市後監督」必須恪守：(f)醫療器材使用管理、(g)醫療器材廣告管理、(h)醫療器材進出口管理、(i)醫療器材不良事件監測管理、(j)醫療器材召回管理、(k)醫療器材監督檢查和(l)醫療器材行政處罰等各項法規與條例。 研究結論歸納，2014年最新修訂的中國大陸《醫療器械監督管理條例》主要是：(1)風險管理分級、(2)審查制度精簡、(3)產品流向追蹤、(4)監管功能強化以及(5)明確法律責任。 / This study aimes to determine the regulations for the supervision and administration of medical devices which is able to educate citizen to complying with the law, ensuring the quality of medical products, maintaining fair competition in the market, protecting the safety and health of people utilization. Furthermore, according to the breadth and complexity of the industry, this proposal can be directed rules as reference in case encountered juridic liability, legal issues or wrongful circumstances before acquired appreciable support from counsellor. The research topics of this article are (1) Examining the draft laws, regulations and rules and policy plots on the governance of medical devices in China. (2) Understanding the development of medical devices regulatory system in China. (3) Exploring the regulatory responsibility of medical devices and penalize illegal behavior in China. Content analysis methodology was conducted for this overview, this writings evaluated regulations of medical devices and administrative institution. Quality system regulations were also investigated by the comparative analysis along with China, European Union, Japan, Taiwan, R.O.C. and the United States. Results reveal that the regulations of medical devices are belong to administrative statute level, the supervision of meical devices is divided to pre-market review and post-market surveillance. Pre-market review contains (a) inspection management, (b) registered management, (c) production management, (d) manuals, labeling and packaging management and (e) advertisement management. Post-market surveillance embodies (f) the application of medical devices management, (g) medical devices advertising management, (h) medical devices import and export management, (i) medical devices monitoring and management of adverse events, (j) medical devices recall management, (k) supervision and inspection of medical dvices together with (l) medical devices regulations and administrative penalties, and other regulations. The findings were summarized as the following statements, the essentials on the latest revised regulations for the supervision and administration of medical devices in China in 2014 are (1) risk based classification, (2) market notification and approval, (3) products sales tracking, (4) supervisory functions strength and (5) distinct legislative liability.

This thesis presents a qualitative study of the role of devices in the technological innovation phenomena of two venture medical equipment companies located in the Midlands, UK. The inquiry takes an empirical and non-foundational approach based on post-ANT and process philosophy. In particular, the thesis employs the theoretical lenses of both ANT and post-ANT concepts, Deleuze’s and Guattari’s machinic thought and Michel Serres’ parasitic philosophy. The data for this thesis comes from a fieldwork study lasting around one year. The methodology is mainly based on interviews and observations of engineers, technicians and managers working in venture companies. The central argument of this thesis shows that the venture organizing process of technological innovation is the product of discursive and non-discursive elements that act in several forms, keeping the venture company working but crucially reorganizing it. The present thesis offers a conceptualization of the device as a parasite-selector that reorganizes the venture company’s work activities and brings novelty to their operation. Equally, the mediational power of diagrams - which presents constitutional indifference - participates in the definition and production of the engineers’, managers’ and technicians’ professional identities. The thesis shows how the ideas regarding innovation in use at Med Dialysis and Med Diabetes bring forth the necessity of a life that embraces the uncertainty and ambiguity of the market. As a consequence, engineers and technicians build their professional identities by embracing the uncertainty of the venture company. This thesis names this process ‘engineering the engineer’. This is a process that leads to the emergence of a professional identity that this thesis tentatively calls the ‘venture engineer’.