Ultra-wideband Breast Cancer Detection Research Articles

A compact ultra-wideband sub-nanosecond pulse generator with step recovery diodes

This article presents a compact ultra-wideband (UWB) sub-nanosecond monocycle pulse generator. The proposed circuit has a simple structure and low cost, and its core components are step recovery diodes (SRDs). It is composed of a power supply circuit, pulse drive circuit, short pulse-forming circuit, and pulse-shaping circuit. A transistor-based drive circuit is used to generate a drive pulse with sharp fall time. Then, a sub-nanosecond pulse width is realized through the combination of two SRDs in series and parallel. Finally, a monocycle pulse is directly formed by the inductance-based differentiator. This design achieves a full pulse width of 406 ps with a 260 mV peak-to-peak amplitude and a −10 dB bandwidth of 510 MHz to 6.1 GHz at a pulse repetition frequency of 10 MHz square waveform. The symmetry and ringing level are 96.9% and −25.3 dB, respectively, providing good symmetry and low ringing with a circuit size of 55 × 15 mm. In actual experiments, two identical UWB antennas with appropriate bandwidth are used to radiate a monopulse to breast phantoms. The results and uncertainty analyses of the test system show that there are distinguishable differences under diverse tumor phantoms and locations, proving that the proposed pulse generator is attractive for the application of UWB breast cancer detection.

Flexible 16 Antenna Array for Microwave Breast Cancer Detection.

Radar-based microwave imaging has been widely studied for breast cancer detection in recent times. Sensing dielectric property differences of tissues has been studied over a wide frequency band for this application. We design single- and dual-polarization antennas for wireless ultrawideband breast cancer detection systems using an inhomogeneous multilayer model of the human breast. Antennas made from flexible materials are more easily adapted to wearable applications. Miniaturized flexible monopole and spiral antennas on a 50-μm Kapton polyimide are designed, using a high-frequency structure simulator, to be in contact with biological breast tissues. The proposed antennas are designed to operate in a frequency range of 2-4 GHz (with reflection coefficient (S11) below -10 dB). Measurements show that the flexible antennas have good impedance matching when in different positions with different curvature around the breast. Our miniaturized flexible antennas are 20 mm × 20 mm. Furthermore, two flexible conformal 4 × 4 ultrawideband antenna arrays (single and dual polarization), in a format similar to that of a bra, were developed for a radar-based breast cancer detection system. By using a reflector for the arrays, the penetration of the propagated electromagnetic waves from the antennas into the breast can be improved by factors of 3.3 and 2.6, respectively.

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Ultra Wideband Breast Cancer Detection by Using SAR for Indication the Tumor Location

Design and Test of an Imaging System for UWB Breast Cancer Detection

Electromagnetic ultra-wideband (UWB) sensing and imaging provide perspectives for early-stage breast cancer detection. This paper deals with practical chal- lenges of real measurements. We present an experimental setup for breast phantom trials based on M-sequence radar technology and short active dipole antennas. It com- bines short impulse responses, appropriate fidelity and very small antenna dimension and allows array construc- tion with sufficient number of antennas around the breast. The basic approach and obtained imaging results are pre- sented. Furthermore, in this extended paper version con- tinuative development steps are described and measure- ment results reflecting specific performance aspects are discussed.

An overview of radar based ultra wideband breast cancer detection algorithms

Breast cancer is the most common cancer in women in almost all countries around the world, and is one of the most common non-infective causes of death. Mammography, which uses ionising radiation, is the only early breast cancer screening technique proven to reduce breast cancer mortality in randomised controlled clinical trials. However, screening mammography is expensive, technically demanding and requires a high level of clinical expertise. It cannot be performed in general medical clinical settings readily. Ultra wideband (UWB) or microwave breast screening has the potential to be a safe, accurate and easy-to-use technique for breast disease detection that is more effective than routine clinical palpation or breast self-examination. Ultra wideband breast cancer detection algorithms have been researched by several groups for over a decade, with numerous algorithms reported. This paper serves to give an overview of existing algorithms for UWB breast cancer detection.

Effect of Lesion Morphology on Microwave Signature in 2-D Ultra-Wideband Breast Imaging

This paper studies the possibility of distinguishing between benign and malignant masses by exploiting the morphology-dependent temporal and spectral characteristics of their microwave backscatter response in ultra-wideband breast cancer detection. The spiculated border profiles of 2-D breast masses are generated by modifying the baseline elliptical rings based upon the irregularity of their peripheries. Furthermore, the single- and multilayer lesion models are used to characterize a distinct mass region followed by a sharp transition to background, and a blurred mass border exhibiting a gradual transition to background, respectively. Subsequently, the complex natural resonances (CNRs) of the backscatter microwave signature can be derived from the late-time target response and reveal diagnostically useful information. The fractional sequence CLEAN algorithm is proposed to estimate the lesions' delay intervals and identify the late-time responses. Finally, it is shown through numerical examples that the locations of dominant CNRs are dependent on the lesion morphologies, where 2-D computational breast phantoms with single and multiple lesions are investigated. The analysis is of potential use for discrimination between benign and malignant lesions, where the former usually possesses a better-defined, more compact shape as opposed to the latter.

Time of Arrival Data Fusion Method for Two-Dimensional Ultrawideband Breast Cancer Detection

A new microwave imaging method is given for breast tumor detection using an ultrawideband (UWB) imaging system. By combining the time of arrival (TOA) measurements from different sensors, the presence and location of small malignant lesions can be identified. At each sensor, the generalized sequence CLEAN (GS-CLEAN) algorithm is proposed to resolve the impulse response (IR) components into bins smaller than the duration of the sounding pulse. This novel deconvolution technique, working well with largely continuous image content, also solves an inverse problem to estimate the unknown tumors' morphological/dielectric properties and delay intervals. Subsequently, the TOA data fusion step is applied to obtain an estimate of the locations of dominant scattering sources such as cancerous tumors. We also apply the entropy-based approaches to collectively estimate the tumor morphological and electrical features based on the information acquired at various antenna elements. Preliminary two-dimensional (2-D) analysis and simulations demonstrate that the system developed is feasible to detect small breast malignant masses using this approach.

Co-polarised and cross-polarised antenna arrays for breast, cancer detection

The detection capabilities of two novel co-polarised and cross-polarised antenna arrays consisting of two slot antennas have been studied and compared for the purpose of ultra-wideband breast cancer detection. For both arrays, the measured antenna return loss is below −10 dB from 3.1 to 10 GHz. The measured coupling between the two elements is below −20 dB for the co-polarised and −25 dB for the cross-polarised formation. It is shown through simulations and measurements that the cross-polarised array improves the signal-to-clutter ratio for tumours close to a planar chest wall.