Ross E. Bland

A Nyquist folding analog-to-information receiver

Many radar and communications applications require detection and estimation of signal information across an extremely wide radio frequency (RF) bandwidth. In practice, however, direct digitization of this broadband RF environment is problematic. Physical limitations in analog-to-digital converter (ADC) technology restrict the total bandwidth that can be digitized, as well as the ability to digitize high RF signals directly. This paper describes a novel ldquoanalog-to-informationrdquo receiver, motivated by recent developments in compressed sensing (CS), which overcomes both of these challenges in certain settings. The proposed receiver performs frequency modulated pulsed sampling at sub-Nyquist/Shannon rates to compress a broadband RF environment into an analog interpolation filter. The RF sample clock modulation induces a Nyquist-zone dependent frequency modulation on the received signals, allowing separation and recovery of the signal information from a sparse broadband RF environment.

Employment after Radiation Oncology Residency: A Survey of the Class of 2014

The number of US radiation oncology training positions offered in the National Resident Matching Program increased by 56% in the last decade, from 128 positions in 2006 to 200 positions in 2015 (www.nrmp.org). This increase parallels a report that predicted demand for radiation therapy between 2010 and 2020 would grow faster than supply (1). However, there is a growing concern that the radiation oncology job market is unfavorable for graduating residents and will only worsen as the effect of increasing the number of training positions is realized over the coming years (2). There has not been a direct measure of radiation oncology new graduate employment since the 1990s (3, 4). We surveyed the 2014 graduates of US radiation oncology training programs about their employment experience.

Inverse 4D conformal planning for lung SBRT using particle swarm optimization.

A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%-41% for D max esophagus, 31%-68% for D max spinal cord and 7%-32% for V 13 lung.

A reconfigurable direct RF receiver architecture

This paper describes a bandpass sampling architecture for direct RF conversion that is reconfigurable and efficient. The receiver architecture avoids the requirement for high clock speeds and fast quantizers by using a two-stage sampling process. In the first stage, the RF signal is bandpass filtered and sampled using an impulse-like sampling device without quantizing the signal. After continuous time low-pass or bandpass filtering, the resulting analog signal is then sampled and quantized by a traditional analog-to-digital converter. This architecture also provides a high degree of reconfigurability in tuning range and bandwidth by using a tunable or selectable anti-aliasing filter before the first stage of sampling and by using a tunable sample clock in the first stage of sampling.

Radiotherapy and Third Generation Concurrent Chemotherapy Agents

Evidence shows that treating locally advanced non-small cell lung cancer (NSCLC) patients with concurrent radiation and second generation chemotherapy agents provides a survival benefit when compared to delivering the same therapy sequentially. However, survival results remain dismal and concurrent chemoradiation exhibits significant toxicity. As third generation chemotherapy agents have become available, their radiation-sensitizing properties have been extensively studied in the laboratory. Subsequently, clinical studies have been performed to evaluate the potential benefit of incorporating these newer agents in concurrent chemoradiation regimens. This chapter aims to provide insight into how these agents were transitioned from the laboratory bench to their current role in the standard of care of patients with locally advanced disease.