Nanocomposite materials for sensing in next-generation minimally-invasive medical devices

Lead Research Organisation: University College London
Department Name: Medical Physics and Biomedical Eng

Abstract

My vision for the EPSRC UKRI Innovation Fellowship is to create a new generation of cutting-edge medical devices for minimally-invasive surgeries, using Materials Chemistry innovations. The devices I will develop will provide improved imaging for guidance and diagnosis during surgeries, as well as precise device locations for example, in magnetic resonance imaging (MRI)-guided interventions. These devices will improve the safety and efficiency of minimally-invasive procedures, and help to reduce the risk of associated complications. One of my key objectives is to translate this healthcare technologies research from academia to pre-clinical validation, providing patient benefits through improved healthcare diagnostics and treatments. Through clinical and industrial collaboration, I will take the healthcare technologies developed during this Fellowship from the benchtop to pre-clinical validation, and establish the most appropriate pathways for commercialisation.

Over the course of the Fellowship I will work towards developing a portfolio of medical devices. The two key devices that I will focus on are:
1) A fibre-optic magnetic field sensor: This miniature sensor will be incorporated into medical devices to facilitate their tracking via magnetic sensing.
2) A fibre-optic ultrasound transmitter with photoacoustic (PA) imaging functionality: This miniature ultrasound transmitter and a fibre-optic ultrasound receiver will be integrated into medical devices to help guide minimally-invasive surgical procedures through ultrasound imaging, providing visualisation of clinically-relevant tissue structures with structural and molecular contrast.

The fibre-optic magnetic sensors will be fabricated by creating elastomeric membranes that are highly deformable in the presence of a magnetic field. These will be developed by incorporating nanoscale magnetic particles into elastomers, and using a range of coating techniques to create micron-scale, freestanding membranes. These membranes will be fabricated into fibre-optic sensors that can be integrated into needles and catheters used for minimally-invasive surgeries. When placed within an MRI-scanner, these devices will respond to changes in the magnetic field in the presence of different gradients, enabling precise device tracking. This technology will open up new avenues for MRI-guided interventions.

The fibre-optic ultrasound transmitter with PA imaging functionality will be created using specially engineered coatings deposited onto optical fibres. These coatings will be designed to strongly absorb visible light within specific wavelength regions for ultrasound generation, and demonstrate transparency to light of other wavelengths for PA imaging. Combined with a fibre-optic ultrasound receiver designed at UCL, this miniature imaging system will be integrated into medical devices used to perform minimally-invasive surgical interventions, for example, cardiovascular procedures. The fibre-optic imaging system will provide unparalleled image guidance from within the needle used to perform the surgery, reducing the risk of complications. The combined ultrasound and PA imaging will provide clinicians with information on tissue structure, as well as molecular information i.e. where lipid rich (fatty) regions are. The latter, can be important for diagnosis and monitoring of atherosclerotic plaques, which are a key cause of cardiovascular disease. Next-generation devices will incorporate both magnetic sensing and ultrasound imaging capabilities, to enable ultrasound-guided interventions, with precise device tracking.

The materials technologies developed will also be translated onto centimetre-scale ultrasound sensors to create a handheld, wide-field all-optical imaging system that can provide three-dimensional combined ultrasound and PA imaging. Potential applications of this system include the detection of head-and-neck cancers, as well as peripheral vascular disease.

Planned Impact

This research is focused on developing new materials for medical devices, to introduce imaging and guidance modalities to improve safety and efficiency in minimally-invasive surgeries. These cutting-edge healthcare technologies greatly benefit the clinical community. The use of Materials Chemistry innovations in Medical Physics technologies such as all-optical ultrasound transmitters, has already rapidly advanced their development, resulting in miniature devices that achieve high ultrasound pressures and wide bandwidths. These properties correspond to high spatial resolution in imaging applications. This research has attracted significant interest from the scientific community, culminating in high impact publications. The Materials Chemistry innovations developed in this Fellowship research will likewise facilitate the advancement of medical device technologies, and will attract much interest from the immediate research community, as well as feed into other research areas where thickness controlled nanocomposites are utilised. I will also set up a Scientific workshop on Materials for Healthcare Technologies to bring together Researchers, Clinicians and industry representatives. This will be of great benefit to all attendees, as it will provide a platform to form critical collaborations to advance the development of healthcare technologies.

The development of optical magnetic sensors and miniature multimodality imaging devices will be of great benefit to the NHS; The improved visualisation and tracking capabilities enabled by these medical devices will result in improved patient outcomes in minimally-invasive surgeries through enhanced surgical precision, reduced procedural times and risks of complications. This will reduce NHS costs of surgical interventions, as well as potential costs of corrective surgeries. The devices will also benefit clinicians, providing cutting-edge imaging modalities to guide minimally-invasive surgeries, facilitating treatment and diagnosis. In particular, the proposed multimodality imaging device will enable visualisation of tissue with molecular contrast, and have applications for example, in cardiology, to enhance the identification of atherosclerotic plaques, a key cause of cardiovascular disease. The research achieved through this fellowship will consequently impact on the public through improved health.

Currently, there is a drive towards performing surgeries with minimal invasiveness and to achieve this, improved image guidance, diagnostic and tracking technologies are crucial. The proposed research will contribute to strengthening the UK's position in cutting-edge surgical interventions, as well as as a leader in healthcare technologies. The proposed technologies are reliant upon UK expertise in lasers, e.g. ElforLight (UK laser manufacturer) and the clinical translation of these technologies will boost UK industry in this sector. Moreover, the UK is a hub for Nanotechnology and Materials Science innovations and it is envisaged that the development and manufacture of the composite materials required for developing these devices will remain in the UK. This will benefit both the UK Nanotechnology and polymer industries.

Lastly, passionate about public engagement, during this Fellowship I plan to be involved in open days, science festivals and other scientific engagement events. I have previously co-organised an exhibit for the Royal Society Summer Science Exhibition and was inspired by the enthusiasm and interest of the public regarding cutting-edge healthcare technologies. I plan to continue engaging with the public during this Fellowship to showcase research outputs. I will also train up a team of volunteers-for the Royal Society Summer Science Exhibition this was >30 people. This will provide the volunteers with skills needed for science engagement, enabling them to continue disseminating research on the public stage.

Publications

10 25 50
 
Title Knowledge is Power Zine 
Description Worked closely with artist Soofiya to organise and host a zine-making patient workshop and deliver a 'research and art collaborative zine' to help empower patients undergoing surgeries 
Type Of Art Artefact (including digital) 
Year Produced 2022 
Impact The zine was distributed at the WEISS In-Theatre pop-up installation that ran from 17 October - 6 November 2022 at 28 Brick Lane, London. Over the 3-week period that the installation was open, over 2000 people came to see it. For more information on the installation please go to: https://www.ucl.ac.uk/interventional-surgical-sciences/public-engagement/theatre/about-theatre 
URL https://www.ucl.ac.uk/interventional-surgical-sciences/sites/interventional_surgical_sciences/files/...
 
Description Over the course of the Fellowship I worked towards developing a portfolio of materials for medical device integration. The two key devices that I focused on materials development for were:

1) A fibre-optic magnetic field sensor with miniature dimensions that is well-suited for incorporation into medical devices, to facilitate their tracking via magnetic sensing.

2) A fibre-optic ultrasound transmitter with photoacoustic (PA) imaging functionality. These transmitters are designed with miniature lateral dimensions and when combined with a fibre-optic ultrasound receiver fabricated by a collaborating group, are well-suited for integration into medical devices to help guide minimally-invasive surgical procedures through ultrasound imaging, providing visualisation of clinically-relevant tissue structures with structural and molecular contrast.

The fibre-optic magnetic sensors were be fabricated by creating elastomeric membranes that are highly deformable in the presence of a magnetic field. Highly magnetically deformable materials were developed by incorporating carbonyl iron particles into skin-safe elastomers (for example, ecoflex), and using a range of coating techniques to either create micron-scale, freestanding membranes or create coatings directly onto the fibre tip. These elastomeric materials were fabricated into fibre-optic sensors that responded to changes in the magnetic field in the presence of different gradients. It is hopeful that this technology will ultimately enable precise device tracking within clinical MR environments and will open up new avenues for MRI-guided interventions.

A range of fibre-optic ultrasound transmitting coatings were designed and created onto optical fibres with coatings engineered to enable both optical ultrasound and multimodality functionality. Some of these coatings were created using candle-soot nanoparticles and a silicone elastomer (as an alternative to coatings designed using costly carbon nanotubes that have higher associated toxicities). These broadly optically absorbing coatings enabled optical ultrasound generation and we demonstrated their potential for applications such as monitoring ablation (ex vivo). Other coatings using quantum dots were designed to strongly absorb visible light within specific wavelength regions for ultrasound generation providing information on tissue structure, and demonstrate transparency to light of other wavelengths for PA imaging providing molecular information i.e. where lipid rich (fatty) regions are. The latter, can be important for diagnosis and monitoring of atherosclerotic plaques which are a key cause of cardiovascular disease. Combined with a fibre-optic ultrasound receiver designed at UCL, this miniature imaging system is well-suited for integration into medical devices used to perform minimally-invasive surgical interventions, for example, cardiovascular procedures to enable unparalleled image guidance from within the needle used to perform the surgery, reducing the risk of complications.

The materials technologies developed have also been translated onto centimetre-scale ultrasound sensors designed at UCL, to create a handheld, wide-field all-optical imaging system that can provide three-dimensional combined ultrasound and PA imaging. Here, gold nanoparticle elastomeric coatings were fabricated as thin, free-standing, centimetre-scale membranes. Potential applications of this system include the detection of head-and-neck cancers, as well as peripheral vascular disease.
Exploitation Route The next steps are to integrate the technologies developed within this research programme and undertake pre-clinical investigations.
Sectors Healthcare

 
Description During this Fellowship I was appointed as an academic lead for the University College London In-Theatre Project. Through this project I had the opportunity to collaborate with zine artist Soofiya and organise a zoom-based zine-making workshop where people with experience of surgical interventions could share their perspectives and discuss their personal experiences. The workshop was well-attended with 14 online public attendees. The workshop facilitated discussions and inspired the attendees' zines. Key themes throughout the workshop included patient communication, information and innovation. Using the zine attendee outputs, I worked with Soofiya to produce a zine called "Knowledge is Power" that compiled views, experiences, key themes and tips for patients that emerged from the workshop. 200 copies were printed and 125 were distributed through the In Theatre exhibition. This zine is also available online at: https://www.ucl.ac.uk/interventional-surgical-sciences/file/2074
First Year Of Impact 2022
Sector Healthcare
Impact Types Societal

 
Description All-Optical Ultrasound Imaging for Gastrointestinal Interventions
Amount £56,800 (GBP)
Funding ID 203145/Z/16/z 
Organisation Wellcome / EPSRC Centre for Interventional and Surgical Sciences 
Sector Public
Country United Kingdom
Start 03/2020 
End 04/2022
 
Description WHOLE-BODY, HIGH RESOLUTION, 3D, SMALL ANIMAL PHOTOACOUSTIC AND ULTRASOUND COMPUTED TOMOGRAPHY SYSTEM
Amount £1,233,566 (GBP)
Funding ID EP/T014369/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 09/2020 
End 09/2024
 
Title Thermal Modelling of Fibre-Optic Laser Generated Ultrasound Transmitters - Data.zip 
Description Optical generation of ultrasound has broad applicability in diagnostic and therapeutic clinical applications. With fibre-optic ultrasound transmitters, ultrasound waves are generated photoacoustically by laser pulses incident on an optically-absorbing coating at the distal end of an optical fibre. Energy from the laser pulses that is not converted to ultrasound raises the temperature of the transmitter coating and surrounding medium. Limiting the maximum temperature is important for tissue safety and the integrity of the transmitter. In this study, we used a finite element thermal model of a fibre-optic ultrasound transmitter to study the influence of three parameters on the temperature rises in the transmitter and the surrounding medium: the laser pulse energy, the laser pulse repetition frequency, and the coating absorption coefficient. To evaluate the validity of the model, the simulation results were compared with thermal imaging experiments of a carbon-polydimethylsiloxane composite-based fibre-optic ultrasound transmitter. Of the studied parameters, the pulse repetition frequency (PRF) has the greatest impact on the temperature rise in the surrounding medium, with a six-fold rise in temperature change resulting from an increase in PRF from 100 Hz to 1 kHz. Our findings have direct applicability to optimising the performance of fibre optic transmitters. 
Type Of Material Database/Collection of data 
Year Produced 2024 
Provided To Others? Yes  
URL https://rdr.ucl.ac.uk/articles/dataset/Thermal_Modelling_of_Fibre-Optic_Laser_Generated_Ultrasound_T...
 
Title Thermal Modelling of Fibre-Optic Laser Generated Ultrasound Transmitters - Data.zip 
Description Optical generation of ultrasound has broad applicability in diagnostic and therapeutic clinical applications. With fibre-optic ultrasound transmitters, ultrasound waves are generated photoacoustically by laser pulses incident on an optically-absorbing coating at the distal end of an optical fibre. Energy from the laser pulses that is not converted to ultrasound raises the temperature of the transmitter coating and surrounding medium. Limiting the maximum temperature is important for tissue safety and the integrity of the transmitter. In this study, we used a finite element thermal model of a fibre-optic ultrasound transmitter to study the influence of three parameters on the temperature rises in the transmitter and the surrounding medium: the laser pulse energy, the laser pulse repetition frequency, and the coating absorption coefficient. To evaluate the validity of the model, the simulation results were compared with thermal imaging experiments of a carbon-polydimethylsiloxane composite-based fibre-optic ultrasound transmitter. Of the studied parameters, the pulse repetition frequency (PRF) has the greatest impact on the temperature rise in the surrounding medium, with a six-fold rise in temperature change resulting from an increase in PRF from 100 Hz to 1 kHz. Our findings have direct applicability to optimising the performance of fibre optic transmitters. 
Type Of Material Database/Collection of data 
Year Produced 2024 
Provided To Others? Yes  
URL https://rdr.ucl.ac.uk/articles/dataset/Thermal_Modelling_of_Fibre-Optic_Laser_Generated_Ultrasound_T...
 
Description Collaboration with Prokopovich Group (University of Cardiff) 
Organisation Cardiff University
Department School of Pharmacy and Pharmaceutical Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution We developed a range of highly magnetically deformable elastomers with varying concentrations of magnetic particles for integration into optical magnetic field sensors.
Collaborator Contribution Our partners (Prokopovich group) undertook mechanical testing of a range of materials fabricated to determine their Young's modulus and to help facilitate materials optimisation.
Impact 10.1002/adfm.202301857
Start Year 2021
 
Description iCASE studentship 
Organisation Johnson Matthey
Department Johnson Matthey Technology Centre
Country United Kingdom 
Sector Private 
PI Contribution Supervision and training of PhD student to develop wavelength-selective nanocomposite coatings on minute targets.
Collaborator Contribution In-kind contribution by JM: Sample characterisation using TEM/FIB/SEM, Development of new nanomaterials, Supervision and input
Impact DOI: 10.1117/12.2549559 Ultrasonics 2020: Fibre-Optic Ultrasound Probes Coated with CuInS2 Quantum Dot-PDMS Films.
Start Year 2018
 
Title A SENSOR FOR MEASURING A FLOW OF A FLUID 
Description A sensor is provided for measuring a flow of a fluid in a physiological environment, such as within a vessel of a human or animal subject. The sensor comprises an interrogation light guide extending from a proximal end to a distal end of the sensor. The interrogation light guide is configured to transmit interrogation light to, and receive reflected interrogation light from, the distal end of the sensor. The sensor further comprises an excitation light guide configured to transmit excitation light to the distal end of the sensor. The excitation light is provided for heating the fluid (directly or indirectly). The sensor further comprises a sensing element located at the distal end of the sensor. The sensing element comprises at least two etalons for reflecting interrogation light back along the interrogation light guide towards the proximal end of the sensor. Each etalon has a respective optical path length and further has at least one reflective surface external to the interrogation light guide. The sensing element is configured to be in thermal contact with the fluid such that the optical path length of at least one etalon is dependent on a temperature of the fluid. The reflected interrogation light forms an interferogram which is dependent on the optical path lengths of the respective etalons. 
IP Reference US2021052173 
Protection Patent application published
Year Protection Granted 2021
Licensed Yes
Impact Patent applications in: EP (EP3743694A1) US (US20210052173A1) JP (JP2020560611A) CA (CA3089265A1) GB (GB2570332A) [WO (WO2019142006A1)]
 
Title ULTRASOUND IMAGING PROBE 
Description An ultrasound probe comprises an optical light guide comprising a multi-mode optical waveguide for transmitting excitation light and a single-mode optical waveguide for transmitting interrogation light. The probe further comprises an ultrasound transmitter located at a distal end of the probe, the ultrasound transmitter comprising an optically absorbing material for absorbing the excitation light from the multi-mode optical waveguide to generate an ultrasound beam via the photoacoustic effect. The probe further comprises an ultrasound receiver including an optical cavity external to the single-mode optical waveguide. The interrogation light from the single-mode optical waveguide is provided to the ultrasound receiver. The optical cavity has a reflectivity that is modulated by impinging ultrasound waves. The interrogation light is reflected from the optical cavity to a proximal end of the single-mode optical waveguide where it can be received for generating a signal. At least a portion of the ultrasound probe is configured to rotate so that the ultrasound beam is transmitted in a rotating direction. 
IP Reference US2021251605 
Protection Patent application published
Year Protection Granted 2021
Licensed Yes
Impact Patent applications in: EP (EP3806750A1) US (US20210251605A1) GB (GB2570332A) [WO (WO2019239148A1)]
 
Description In Theatre- an interactive pop-up installation, which explored how AI and robotics will revolutionise surgery now and in the future 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I have deeply participated in 'In-Theatre'- an interactive public installation and arts-based community engagement programme, which was designed using arts-based approaches effective at helping people discuss challenging topics and breaking down barriers to engagement.

As one part of the WEISS public engagement team, I was actively involved in the 'Deep-listening' project, and co-led one of seven workshops, Making the Invisible Visible- The Art of the Medical Scan, with two artists Arieh Frosh and Ed Compson, as the academic advisor. Five people from East London who have had medical scans took part in the workshop. They were taken through a variety of processes that stimulated a discussion about people's experiences of different health professionals interpreting the same scan images differently, and the advantages of using AI to introduce consistency and remove bias. The workshop resulted in images that were available to visitors of the In-Theatre installation.

I have also participated in running the pup-up installation housed in the heart of Brick Lane. Over the 3-weeks that the pop-up installation was open, we welcomed over 2000 people in to see the project. Visitors to In Theatre were led on a journey deep inside the human body and were sent whizzing through the high-tech machines used during surgery. They were invited to beat the buzzer to test just how steady their hands were compared with the arms of a robot surgeon and could sit in on a virtual robotic operation.
Year(s) Of Engagement Activity 2021,2022
URL https://www.ucl.ac.uk/interventional-surgical-sciences/public-engagement/theatre
 
Description SURGE Online SciArt Gallery - contributed to OpUS exhibit led by researcher Dr Richard Colchester and artist Priya Odedra. Contributed two audio clips that were created into short animated videos - one of which featured in exhibit. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Patients, carers and/or patient groups
Results and Impact Online Science Arts gallery - arts science collaboration between UCL researchers and artists to connect members of public with researchers working on new medical technologies e.g. minimally invasive medical imaging devices to help guide surgeries. This exhibit, led by Dr Colchester, involved contacting heart patients/ families and young people aged 16-18 and asking them to complete a short survey to discover their experiences and views, or concerns about technologies. In response to the outcome of the survey, researchers contributed short audio clips/videos which were collated and exhibited in an online gallery.
Feedback included that the exhibit was "inspiring", public were "excited about the work" and they "loved the idea of combining Art and Science"

SURGE SciArt Gallery Launch URL: https://www.youtube.com/watch?v=sXDQ7QySo0M
Year(s) Of Engagement Activity 2021
URL https://www.youtube.com/watch?v=KmiJy9BmsUE&list=PLVtCXK1JHQp4DmpL2UnT69tqg-_4JIgYG&index=5
 
Description Science Museum Half Term week 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Exhibited our research at a stall for the Science Museum Half Term week activities 2020 in the newly opened medical gallery. We communicated our research to at least 800 people over 2 days. It was a mixed public ranging from toddlers, school children to parents and other interested adults. The stall inspired the young children and sparked a lot of interest about the general research theme and how the technology worked.
Year(s) Of Engagement Activity 2020
 
Description Science Museum Lates January 2020 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Exhibited our research at a stall for the Science Museum Lates 2020 (celebrated opening of new medical gallery). We communicated our research to at least 590 people over 2 stalls (one directly associated with this project). The public was over 18s and the stall sparked lots of interesting questions and discussions on the research exhibited. We have been asked to exhibit our research in the upcoming Science Museum half term week events to engage with schoolchildren.
Year(s) Of Engagement Activity 2020
 
Description WEISS In-Theatre Installation 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I was an academic lead for In Theatre project delivery group, representing WEISS's research interests. I also worked closely with artist Soofiya to organise and deliver a zine-making patient workshop (see Artistic and Creative products section).
For more information on the In-Theatre installation, please see the attached link: https://www.ucl.ac.uk/interventional-surgical-sciences/public-engagement/theatre/about-theatre
Year(s) Of Engagement Activity 2022