60 years of the medical physics revolution

With the Ray Optics Module, an add-on product to the COMSOL Multiphysics® software, you can use simulation to predict the paths of light rays, including diffuse and specular reflection, refraction, absorption and dispersion of polychromatic light. You can also analyse ray intensity, polarization and monochromatic aberrations.

This webinar will focus on how ray tracing can be combined with other types of physics in a model. For example, you can model the effects of thermal stress in high-powered laser focusing systems and even couple wavelength-scale modelling of antennas and semiconductor devices to ray tracing simulations on a much larger scale.

The webinar includes a live demonstration and will conclude with a Q&A session.

The quality control (QC) of radiation-therapy (RT) treatment units is essential to deliver safe and effective radiation-therapy treatments. The complexity of the equipment and treatment techniques demands that many different tests be performed with varying frequencies, making the management of an RT department’s QC programme a complex and time-consuming task. Many professionals such as therapists, service engineers and physicists are working in collaboration to meet the machine QC requirements.

AQUA is a departmental quality-management software that centralizes all of the machine QC activities, helping to manage the complexity of quality-assurance requirements in a radiation-therapy department. AQUA is a server-based application that can be accessed throughout a RT department using a web browser. It uses a centralized database to consolidate all QC tests, procedures and results in one location and offers a workflow manager to guide the users in their day-to-day QC tasks. QC tests in AQUA can easily be created or customized using a XML-based scripting language. Integration between AQUA and the Elekta linear accelerators and other measurement devices (such as MV flat panels, electrometers and 2D arrays) using a built-in software interface has been implemented to automate time-consuming tasks. Finally, review tools such as near-real-time dashboard, plotting tool and reports are available in AQUA to streamline machine-performance assessment.

In this presentation, we will review some of the main AQUA features such as the workflow manager, QC test scripting language, and the dashboard for performance and compliance review. We will also describe test automation for some QC tasks and review the impact on QC workflows and test frequency. We will then discuss the impact of efficient review tools on the ability to detect change in machine performance and to guide servicing decisions. Finally, we will review new features in the up-coming version of the software.

The advent of MRI-guided radiation therapy has introduced MRI’s powerful soft- tissue contrast into the treatment room, offering strong potential for improved targeting in many disease sites. In February 2017, ViewRay’s MRIdian linear accelerator (linac) received FDA clearance and the first patient treatment using MRIdian® Linac was conducted at Henry Ford Cancer Institute in July 2017. In this webinar, two key physicists involved in this project, Anthony Doemer, M.S., and Carri Glide-Hurst, Ph.D., will present their commissioning and clinical experience. Initial site planning, shielding, and MR safety considerations will be shared. The design aspects and functionality of the double-focused MLC, mechanical, and radiation characterization and validation will be presented. Commissioning of the MRI system, including novel aspects such as distortion assessment and field homogeneity in the presence of the linear accelerator will be highlighted. First clinical images and treatment plans will be shared to highlight the first months of clinical operation.

This webinar is essential viewing for radiation-shielding designers in radiation physics, qualified experts and also useful to anyone involved in the design of radiotherapy facilities.

Join authors Patrick Horton and David Eaton for this 45 min webinar as they guide you through their book Design and Shielding of Radiotherapy Treatment Facilities-IPEM Report 75.

There will be a live Q&A session at the end of the webinar.

The ability to visualize immune responses non-invasively would have tremendous value for basic immunology. In pre-clinical models it would be possible to track events such as the host response to infections, to look at inflammation more generally, and to follow the course of interventions such as checkpoint blocking antibodies in the treatment of tumours.

PET imaging agents require a workflow compatible with the half-life of commonly used isotopes, and must take into account the pharmacokinetic properties of these agents. The specificity of what is being imaged requires the design of compounds that can distinguish between differences in metabolic activity (18F-fluorodeoxyglucose) or that serve as ligands for specific receptors, such as antibodies that recognize surface structures. We have used nanobodies, the smallest antibody-derived fragments that retain antigen-binding capacity. These fragments are ~15 kDa in size, are rapidly cleared from the circulation and are easily modified by chemo-enzymatic means for the installation of metal chelators or click handles to enable radiolabelling. Using nanobodies, we have been able to image various populations of immune cells, and based on longitudinal immuno-PET observations we have been able to make predictions of success and failure in immunotherapy of the B16 mouse melanoma model. The use of 89Zr-labelled nanobodies for immuno-PET will be a powerful adjunct to more conventional, invasive models, and will provide resolution superior to fluorescence- and luminescence-based models.

If you are interested in learning about photonics simulation using the COMSOL Multiphysics® software, then tune into this webinar.

Photonics (the generation, detection, and manipulation of light) plays a fundamental role in modern technology. It is used in a wide range of applications, such as telecommunications, medicine, computing, and manufacturing.

During this webinar, we will discuss using COMSOL Multiphysics® for photonics simulations, in particular periodic structures and crystals. We will show how modeling can provide insight into the design and characterisation of photonic devices. This includes solving for the propagation of electromagnetic waves, even in the presence of wavelength-dependent material properties, as well as multiphysics effects like heating or mechanical loading.

The webinar includes a live demonstration and a Q&A session during which you can ask questions.

After the first demonstration of an optical frequency comb based on a mode-locked laser in 1999, Ti:sapphire lasers with repetition rates around 1 GHz were the sources of choice for scientists around the world. Their key feature was a mode spacing 10 times higher than that of comparable 100 MHz sources (simplifying mode identification) and the ability to generate a fully coherent super-continuum with 100 times more power per mode either directly from the cavity or using an external microstructured fibre (enhancing signal-to-noise ratio). The world’s first optical atomic clock was built in 2001 using a 1 GHz Ti:sapphire laser and subsequently it has been shown that these lasers indeed support an accuracy at the 10–20 level with a 1 s stability at the 10–17 level and optical linewidths at the millihertz level, i.e. ideal candidate clockworks for a new generation of optical atomic clocks. The Ti:sapphire technology has even been taken out to as far as 10 GHz, a regime where individual modes with powers in excess of 1 mW can be separated with a grating spectrometer and used individually for direct spectroscopy, spectrograph calibration or optical arbitrary waveform generation.

To overcome some of the disadvantages of early Ti:sapphire lasers (requirement for frequent alignment, cleaning and use of AO modulators for control purposes) and to make the full advantages of GHz frequency comb technology accessible to the science community, Laser Quantum has developed the hermetically sealed and permanently aligned taccor 1 GHz Ti:sapphire laser featuring an integrated pump laser with direct pump power control. This intervention free laser forms the basis for the new taccor comb system featuring an f-2f interferometer and full comb-stabilization electronics.

This webinar reviews the benefits of gigahertz Ti:sapphire frequency combs and focuses on the recent progress using Laser Quantum‘s hermetically sealed line of taccor lasers.

The UK Quantum Technology Hubs led by the Universities of Birmingham, Glasgow, Oxford and York are offering fully funded PhD studentships in the areas of sensing and metrology, enhanced imaging, quantum computing and secure communications, Find out more about each hub’s research and their partners, and the studentship opportunities available.

The UK Quantum Technology Hubs are part of the UK government’s £270 million National Quantum Technologies Programme set up to exploit the potential of quantum science and develop a range of emerging technologies with the potential to benefit the UK.

If you are interested in modelling smart materials and MEMS using COMSOL Multiphysics®, then tune into this webinar.

Smart materials are materials whose properties or shape respond dynamically to stimuli in their environment. For example, piezoelectric materials experience strain under an applied electric field, while magnetostrictive materials deform in the presence of a magnetic field.

In this live webinar, you will learn how to model MEMS sensors and actuators based on smart materials for a wide range of applications, including vibration and active shape control as well as structural health monitoring and energy harvesting. We will also demonstrate the applicability of the COMSOL Multiphysics® simulation environment for coupling mechanical, electrical and thermal models of smart materials.

At the end of this webinar, you can ask questions during the Q&A session.

How to commission and maintain a proton-therapy system.
Expert physicists explain in detail what it entails.

In the fifth and final of our series of webinars showcasing presentations from the PMB 60th Anniversary Symposium, Robert Jeraj from the University of Wisconsin takes a look at what may lie ahead for medical physics in the next 60 years.

The physics of electromagnetic coupling through space is fundamental to modern technology. It is exploited in some devices such as RFID tags and directional couplers to communicate information. In other devices, electromagnetic interference (EMI) is an unwanted effect that must be controlled: for example, the problem of crosstalk in electrical circuits and cables. In this webinar we will discuss the simulation of electromagnetic coupling in a variety of different applications, considering examples of capacitive, inductive and radiative couplings in frequencies from the kHz to GHz range. We will show how modelling can provide insight into design, either to improve the quality of a communication device, or to mitigate EMI through effective electromagnetic shielding. A live demo will illustrate how to simulate antenna crosstalk using COMSOL Multiphysics®. We will conclude this webinar with a Q&A session.

In the fourth of our series of webinars showcasing presentations from the PMB 60th Anniversary Symposium, Katia Parodi examines the key ingredients of modern adaptive radiotherapy, including fast computational models and methods for in-vivo dose/range assessment. She also takes a look forward to the era of biological guidance.

Almost all clinics, small and large, use magnetic resonance images (MRI) in their treatment-planning workflows. Modern treatment planning requires images of high geometric fidelity with high spatial and contrast resolution to delineate disease extent and proximity to adjacent organs at risk. However, imaging protocols needed for accurate treatment planning differ significantly from those used in diagnostic radiology. As the integration of MRI into radiation oncology is expanding rapidly, a need exists to highlight the considerations for safe and effective implementation. This webinar will describe the major differences from diagnostic MRI, provide an overview of MRI safety and training models, introduce clinical-workflow considerations, and describe the development of a robust quality-assurance programme. Special considerations for motion management and treatment planning will be described.

Optical devices are key components in many areas, such as communications, remote sensing and medical applications, and their role will increase in the future. Simulations are already a very efficient way of optimizing a device, even before the prototype stage. However, simulating optical devices needs distinct consideration due to the special material models, such as graphene, or simply due to the size of the device in relation to the wavelengths of interest.

CST STUDIO SUITE® offers a unique platform for handling such challenges. The user may import or build even highly complex structures using a user-friendly, interactive GUI. The photonic/plasmonic behaviour of the device can then be simulated by selecting the most appropriate algorithm (e.g. FIT/FDTD, FEM, BEM/MoM, MLFMM and more). Dispersive, anisotropic and nonlinear materials are supported. High-performance computing (HPC) options, such as MPI or GPU, are available, and the results can be displayed and analysed in the GUI using a comprehensive post-processing library and state-of-the-art visualization engine.

In addition, CST STUDIO SUITE® includes multiphysics solvers linked to EM, allowing users to, for example, simulate the effect of thermal tuning.

This webinar will demonstrate how CST STUDIO SUITE can be used to analyse a number of essential optical devices, such as silicon-on-insulator (SOI) waveguide components, photonic crystals (PC), plasmonic devices and optical gratings.